JP7338262B2 - Image encoding device, image encoding method and image encoding program - Google Patents

Description

The present invention relates to image encoding and decoding techniques for dividing an image into blocks and performing prediction.

In image encoding and decoding, an image to be processed is divided into blocks each of which is a set of a predetermined number of pixels, and each block is processed. Encoding efficiency is improved by dividing into appropriate blocks and appropriately setting intra-prediction and inter-prediction.

Patent Literature 1 discloses an intra-prediction technique for obtaining a predicted image using decoded pixels adjacent to a block to be encoded/decoded.

JP 2009-246975 A

However, the technique of Patent Literature 1 uses only decoded pixels adjacent to a block to be encoded/decoded for prediction, resulting in poor prediction efficiency.

In one aspect of the present invention for solving the above problems, a block vector candidate deriving unit for deriving a block vector candidate of a block to be processed in a picture to be processed from coding information stored in a coding information storage memory; a selection unit that selects a selected block vector from candidates; and a predetermined position of the referable area when it is determined that the reference block referred to by the selected block vector does not fit in the referable area. a reference position correction unit that corrects the reference position of the reference block so as to refer to the reference position, and uses the decoded pixel in the target picture as a prediction value of the target block based on the reference position of the reference block. Acquired from the decoded image memory unit.

According to the present invention, highly efficient image encoding/decoding processing can be realized with a low load.

1 is a block diagram of an image coding device according to an embodiment of the present invention; FIG. 1 is a block diagram of an image decoding device according to an embodiment of the present invention; FIG. FIG. 11 is a flowchart for explaining an operation of dividing a treeblock; FIG. FIG. 4 is a diagram showing how an input image is divided into treeblocks; FIG. 4 is a diagram for explaining z-scan; It is a figure which shows the division|segmentation shape of a block. 4 is a flowchart for explaining an operation of dividing a block into four; 4 is a flowchart for explaining an operation of dividing a block into two or three; This is the syntax for expressing the shape of block division. It is a figure for demonstrating intra prediction. FIG. 4 is a diagram for explaining reference blocks for inter prediction; A syntax for expressing coding block prediction modes. FIG. 4 is a diagram showing the correspondence between syntax elements and modes related to inter-prediction; FIG. 4 is a diagram for explaining affine transformation motion compensation of two control points; FIG. 4 is a diagram for explaining affine transformation motion compensation of three control points; 2 is a block diagram of a detailed configuration of inter prediction section 102 in FIG. 1. FIG. FIG. 17 is a block diagram of a detailed configuration of a normal motion vector predictor mode derivation unit 301 of FIG. 16; FIG. 17 is a block diagram of a detailed configuration of a normal merge mode derivation unit 302 of FIG. 16; 17 is a flowchart for explaining normal predicted motion vector mode derivation processing of the normal predicted motion vector mode deriving unit 301 of FIG. 16; FIG. 10 is a flowchart showing a processing procedure of normal motion vector predictor mode derivation processing; FIG. FIG. 10 is a flowchart for explaining the procedure of normal merge mode derivation processing; FIG. 3 is a block diagram of a detailed configuration of an inter prediction unit 203 in FIG. 2; FIG. FIG. 23 is a block diagram of a detailed configuration of a normal motion vector predictor mode derivation unit 401 of FIG. 22; FIG. 23 is a block diagram of a detailed configuration of a normal merge mode derivation unit 402 of FIG. 22; 23 is a flowchart for explaining normal predicted motion vector mode derivation processing of the normal predicted motion vector mode deriving unit 401 of FIG. 22; FIG. 11 is a flowchart for explaining a history motion vector predictor candidate list initialization/update processing procedure; FIG. FIG. 10 is a flowchart of a same-element confirmation process procedure in the history motion vector predictor candidate update process procedure; FIG. FIG. 10 is a flowchart of an element shift processing procedure in the historical motion vector predictor candidate update processing procedure; FIG. FIG. 10 is a flowchart for explaining a history motion vector predictor candidate derivation processing procedure; FIG. FIG. 10 is a flowchart for explaining history merge candidate derivation processing procedures; FIG. FIG. 10 is a diagram illustrating an example of history motion vector predictor candidate list update processing; FIG. 10 is a diagram illustrating a valid reference area for intra block copy; FIG. 10 is a diagram for explaining motion compensation prediction in the case of L0 prediction in which the reference picture (RefL0Pic) of L0 is before the picture to be processed (CurPic); FIG. 11 is a diagram for explaining motion compensation prediction when L0 prediction is performed and the reference picture for L0 prediction is at a time after the picture to be processed; FIG. 10 is a diagram for explaining motion compensation prediction in the case of bi-prediction where the reference picture for L0 prediction is before the picture to be processed and the reference picture for L1 prediction is after the picture to be processed; . FIG. 10 is a diagram for explaining the prediction direction of motion compensation prediction when bi-prediction is performed and the reference picture for L0 prediction and the reference picture for L1 prediction are located before the picture to be processed; FIG. 10 is a diagram for explaining the prediction direction of motion compensation prediction when bi-prediction is performed and the reference picture for L0 prediction and the reference picture for L1 prediction are located after the picture to be processed; FIG. 11 is a flowchart for explaining an average merge candidate derivation processing procedure; FIG. 10 is a table showing information about merge difference motion vectors; FIG. 10 is a diagram illustrating derivation of a merge difference motion vector; FIG. 2 is a block diagram of a detailed configuration of an intra prediction unit 103 in FIG. 1; FIG. FIG. 3 is a block diagram of a detailed configuration of an intra prediction unit 204 in FIG. 2; FIG. 3 is a block diagram of an intra block copy prediction unit 352; FIG. 3 is a block diagram of an intra block copy prediction unit 362; FIG. FIG. 11 is a flowchart for explaining prediction intra block copy processing of an intra block copy prediction unit 352; FIG. FIG. 11 is a flowchart for explaining prediction intra block copy processing of an intra block copy prediction unit 362; FIG. FIG. 11 is a flowchart for explaining merge intra block copy processing; FIG. FIG. 11 is a flowchart showing a processing procedure of block vector mode derivation processing for predictive intra block copy; FIG. FIG. 11 is a diagram for explaining processing of a reference position correction unit 380 and a reference position correction unit 480; It is a figure which shows an example of a mode that a reference position is correct|amended. FIG. 10 is a diagram showing another example of how the reference position is corrected; FIG. 10 is a diagram showing an example of how the reference position is corrected when the referable area is not rectangular. FIG. 10 is a diagram showing another example of how the reference position is corrected when the referable area is not rectangular.

Techniques and technical terms used in this embodiment are defined.

<Tree Block>
In the embodiment, an image to be encoded/decoded is equally divided into a predetermined size. This unit is defined as a treeblock. As shown in FIG. 4, the size of the treeblock is set to 128×128 pixels in this embodiment, but the size of the treeblock is not limited to this, and any size may be set. The treeblock to be processed (corresponding to the encoding target in the encoding process and the decoding target in the decoding process) is switched in raster scan order, that is, from left to right and from top to bottom. The interior of each treeblock can be further recursively split. A block to be coded/decoded after treeblock division is defined as a coded block. Also, tree blocks and coding blocks are collectively defined as blocks. Appropriate block division enables efficient encoding. The size of the treeblock can be a fixed value that is prearranged between the encoding device and the decoding device, or can be configured such that the treeblock size determined by the encoding device is transmitted to the decoding device.

<Prediction mode>
For each encoding block to be processed, the image to be processed has been processed (in the encoding process, the signal that has been encoded is used for the decoded image, image signal, tree block, block, encoding block, etc. In the decoding process, Intra prediction (MODE_INTRA) that performs prediction from the surrounding image signals of decoded images, image signals, tree blocks, blocks, coding blocks, etc.), and inter prediction that performs prediction from the image signals of processed images Switch (MODE_INTER). A mode for distinguishing between intra prediction (MODE_INTRA) and inter prediction (MODE_INTER) is defined as a prediction mode (PredMode). The prediction mode (PredMode) has intra prediction (MODE_INTRA) or inter prediction (MODE_INTER) as a value.

<Intra block copy prediction>
Intra block copy prediction is a process of encoding/decoding a block to be processed by referring to decoded pixels in a picture to be processed as prediction values. The distance from the block to be processed to the pixel to be referred to is represented by a block vector. Since the block vector refers to the picture to be processed and the reference picture is uniquely determined, no reference index is required. The difference between a block vector and a motion vector is whether the picture referred to is a picture to be processed or a picture that has been processed. In addition, block vectors can be selected from 1-pixel precision or 4-pixel precision using adaptive motion vector resolution (AMVR).

In intra-block copy, two modes of predictive intra-block copy mode and merge intra-block copy mode can be selected.

The predictive intra block copy mode is a mode in which a block vector of a block to be processed is determined from a predictive block vector derived from processed information and a difference block vector. A predictive block vector is derived from a processed block adjacent to the block to be processed and an index for specifying the predictive block vector. An index for specifying a predicted block vector and a differential block vector are transmitted in a bitstream.

The merge intra block copy mode is a mode for deriving intra block copy prediction information of a block to be processed from intra block copy prediction information of processed blocks adjacent to the block to be processed without transmitting differential motion vectors.

<Inter Prediction>
In inter prediction, in which prediction is performed from image signals of processed images, a plurality of processed images can be used as reference pictures. In order to manage a plurality of reference pictures, two types of reference lists, L0 (reference list 0) and L1 (reference list 1), are defined, and reference pictures are specified using reference indices. L0 prediction (Pred_L0) is available for P slices. L0 prediction (Pred_L0), L1 prediction (Pred_L1), and bi-prediction (Pred_BI) are available for B slices. L0 prediction (Pred_L0) is inter prediction that refers to reference pictures managed by L0, and L1 prediction (Pred_L1) is inter prediction that refers to reference pictures that are managed by L1. Bi-prediction (Pred_BI) is inter-prediction in which both L0 prediction and L1 prediction are performed and one reference picture managed by each of L0 and L1 is referred to. Information specifying L0 prediction, L1 prediction, and bi-prediction is defined as an inter-prediction mode. In the subsequent processing, it is assumed that the constants and variables with the suffix LX attached to the output are processed for each of L0 and L1.

<Predicted motion vector mode>
The motion vector predictor mode is a mode in which an index for specifying a motion vector predictor, a differential motion vector, an inter prediction mode, and a reference index are transmitted, and inter prediction information of the block to be processed is determined. The motion vector predictor is a motion vector predictor candidate derived from a processed block adjacent to the target block or a block belonging to the processed image and located in the same position or in the vicinity of the target block (neighborhood), and a motion vector predictor. Derived from the index to identify the vector.

<Merge mode>
Merge mode is a processed block adjacent to the target block, or a block belonging to the processed image and located at the same position as the target block or its vicinity (neighborhood) without transmitting the differential motion vector and the reference index. This mode derives the inter prediction information of the block to be processed from the inter prediction information of the target block.

A processed block adjacent to the block to be processed and the inter prediction information of the processed block are defined as spatial merge candidates. A block belonging to a processed image and located at the same position as or in the vicinity (neighborhood) of the block to be processed and inter prediction information derived from the inter prediction information of the block are defined as temporal merge candidates. Each merging candidate is registered in a merging candidate list, and a merging candidate to be used in prediction of a block to be processed is specified by a merging index.

<Adjacent block>
FIG. 11 is a diagram illustrating reference blocks referred to for deriving inter prediction information in motion vector predictor mode and merge mode. A0, A1, A2, B0, B1, B2, and B3 are processed blocks adjacent to the target block. T0 is a block belonging to the processed image, and is a block located at the same position as or in the vicinity (neighborhood) of the encoding block to be processed of the image to be processed.

A1 and A2 are blocks located on the left side of the target encoding block and adjacent to the target encoding block. B1 and B3 are blocks positioned above the target encoding block and adjacent to the target encoding block. A0, B0, and B2 are blocks positioned at the lower left, upper right, and upper left of the encoding block to be processed, respectively.

Details of how adjacent blocks are handled in motion vector predictor mode and merge mode will be described later.

<Affine transformation motion compensation>
Affine transformation motion compensation divides a coding block into sub-blocks of a predetermined unit, sets a motion vector individually for each sub-block, and performs motion compensation. The motion vector of each sub-block is derived from the inter-prediction information of a processed block adjacent to the target block or a block belonging to the processed image and located at or near the same position as the target block (neighborhood)1 Based on one or more control points. In this embodiment, the size of the sub-block is 4×4 pixels, but the size of the sub-block is not limited to this, and the motion vector may be derived in units of pixels.

FIG. 14 shows an example of affine transform motion compensation when there are two control points. In this case, since the two control points have two parameters of a horizontal component and a vertical component, the affine transformation with two control points is called a four-parameter affine transformation. CP1 and CP2 in FIG. 14 are control points. FIG. 15 shows an example of affine transform motion compensation with three control points. In this case, since the three control points have two parameters of a horizontal component and a vertical component, the affine transformation with three control points is called a six-parameter affine transformation. CP1, CP2, and CP3 in FIG. 15 are control points.

Affine transform motion compensation can be used in both predictive motion vector mode and merge mode. A mode in which affine transform motion compensation is applied in motion vector predictor mode is defined as sub-block motion vector predictor mode, and a mode in which affine transform motion compensation is applied in merge mode is defined as sub-block merge mode.

<Syntax of encoding block>
The syntax (syntax rule of the encoded bit string) for encoding/decoding the prediction mode of the encoded block will be described with reference to FIGS. pred_mode_flag in FIG. 12A is a flag indicating whether inter prediction is performed. If pred_mode_flag is 0, inter prediction is performed, and if pred_mode_flag is 1, intra prediction is performed. In the case of intra prediction, pred_mode_ibc_flag, which is a flag indicating intra block copy prediction, is coded/decoded. If intra block copy prediction (pred_mode_ibc_flag=1), encode/decode merge_flag. merge_flag is a flag indicating whether to use the merge intra block copy mode or the predictive intra block copy mode. Encode/decode merge index merge_idx if merge intra block copy mode (merge_flag=1). If it is not intra block copy prediction (pred_mode_ibc_flag=0), normal intra prediction is used, and normal intra prediction information intra_pred_mode is encoded/decoded.

Encode/decode merge_flag in case of inter prediction. merge_flag is a flag indicating whether to set the merge mode or the motion vector predictor mode. In the case of the motion vector predictor mode (merge_flag=0), encode/decode the flag inter_affine_flag indicating whether to apply the sub-block motion vector predictor mode. When applying the sub-block predictive motion vector mode (inter_affine_flag=1), encode/decode cu_affine_type_flag. cu_affine_type_flag is a flag for determining the number of control points in the sub-block predicted motion vector mode.

On the other hand, in the merge mode (merge_flag=1), the regular_merge_flag in FIG. 12(b) is encoded/decoded. regular_merge_flag is a flag indicating whether to apply the normal merge mode. For regular merge mode (regular_merge_flag=1), encode/decode the merge index merge_idx for regular merge mode. On the other hand, if it is not the regular merge mode (regular_merge_flag=0), it encodes/decodes the flag merge_subblock_flag indicating whether to apply the subblock merge mode. For subblock merge mode (merge_subblock_flag=1), encode/decode merge index merge_subblock_idx. On the other hand, if the subblock merge mode is not set (merge_subblock_flag=0), the block splitting direction merge_triangle_split_dir and the merge triangle indices merge_triangle_idx0 and merge_triangle_idx1 are encoded/decoded for each of the two split partitions.

FIG. 13 shows the value of each syntax element and the prediction mode corresponding thereto. merge_flag=0,inter_affine_flag=0 corresponds to normal predicted motion vector mode (Inter Pred Mode). merge_flag=0, inter_affine_flag=1 corresponds to the sub-block prediction motion vector mode (Inter Affine Mode). merge_flag=1,regular_merge_flag=1 corresponds to regular merge mode. merge_flag=1,regular_merge_flag=0,merge_subblock_flag=0 corresponds to Triangle Merge Mode. merge_flag=1,regular_merge_flag=0,merge_subblock_flag=1 corresponds to subblock merge mode (Affine Merge Mode).

<POC>
POC (Picture Order Count) is a variable associated with a picture to be encoded, and is set to a value that increases by 1 in the order in which pictures are output. Based on the POC value, it is possible to determine whether the pictures are the same, determine the sequential relationship between the pictures in the output order, and derive the distance between the pictures. For example, if two pictures have the same POC value, it can be determined that they are the same picture. When two pictures have different POC values, it can be determined that the picture with the smaller POC value is the picture to be output first, and the difference between the POCs of the two pictures determines the inter-picture distance in the time axis direction. show.

(First embodiment)
An image encoding device 100 and an image decoding device 200 according to the first embodiment of the present invention will be described.

FIG. 1 is a block diagram of an image coding device 100 according to the first embodiment. The moving image coding apparatus of the embodiment includes an image coding apparatus 100, a block division unit 101, an inter prediction unit 102, an intra prediction unit 103, a decoded image memory 104, a prediction method determination unit 105, a residual signal generation unit 106, An orthogonal transform/quantization unit 107 , a bit stream encoding unit 108 , an inverse quantization/inverse orthogonal transform unit 109 , a decoded image signal superimposing unit 110 , and an encoded information storage memory 111 are provided.

The block division unit 101 recursively divides an input image to generate coding blocks. The block dividing unit 101 includes a 4-dividing unit that horizontally and vertically divides a block to be divided, and a 2-3 dividing unit that horizontally or vertically divides a block to be divided. . The generated image signal of the coding block to be processed is supplied to the inter prediction unit 102 , the intra prediction unit 103 and the residual signal generation unit 106 . Information indicating the determined recursive partitioning structure is also supplied to the bit stream encoding unit 108 . A detailed operation of the block division unit 101 will be described later.

The inter prediction unit 102 performs inter prediction of the encoding block to be processed. A plurality of inter prediction information candidates are derived from the inter prediction information stored in the encoded information storage memory and the decoded image signal stored in the decoded image memory 104, and suitable inter prediction is performed from among the plurality of candidates. A mode is selected, and the selected inter-prediction mode and the predicted image signal corresponding to the selected inter-prediction mode are supplied to the prediction method determination unit 105 . A detailed configuration and operation of the inter prediction unit 102 will be described later.

The intra prediction unit 103 performs intra prediction on the encoding block to be processed. In intra prediction, a predicted image signal is created from a decoded region of the same image signal as the target encoding block stored in the decoded image memory 104 and supplied to the prediction method determination unit 105 . A detailed configuration and operation of the intra prediction unit 104 will be described later.

The decoded image memory 104 stores the decoded image generated by the decoded image signal superimposing unit 110 . Also, the decoded image stored in the decoded image memory is supplied to the inter prediction unit 102 and the intra prediction unit 103 .

The prediction method determination unit 105 evaluates each prediction using the coding information and the code amount of the residual signal, the amount of distortion between the predicted image signal and the image signal to be processed, and the like, thereby determining the optimum prediction. Determine the mode (inter prediction or intra prediction). In the case of the inter-prediction merge mode, the encoding information of the merge index and the information indicating whether the sub-block merge mode is selected (sub-block merge flag) is supplied to the bit stream encoding unit 108, and the inter-prediction motion vector prediction mode is encoded. In this case, bitstream encoding section 108 encodes encoded information such as inter prediction mode, predicted motion vector index, L0 and L1 reference indices, differential motion vector, information indicating whether sub-block mode (sub-block predicted motion vector flag), etc. supply to The determined encoded information is supplied to the encoded information storage memory 111 .

The residual signal generation unit 106 generates a residual signal by subtracting the predicted image signal from the image signal to be processed, and supplies the residual signal to the orthogonal transformation/quantization unit 107 .

Orthogonal transformation/quantization section 107 performs orthogonal transformation and quantization on the residual signal according to a quantization parameter to generate an orthogonal transformation/quantized residual signal, and performs bit stream encoding section 108 and inverse quantization. supplied to the normalization/inverse orthogonal transformation unit 109 .

The bit stream encoding unit 108 encodes encoding information according to the prediction method determined by the prediction method determination unit 105 for each encoding block, in addition to the information for each sequence, picture, slice, and encoding block. Specifically, the prediction mode PredMode and the division mode PartMode are encoded for each encoding block. When the prediction mode is intra prediction (PRED_INTRA), a flag (pred_mode_ibc_flag) for determining whether intra block copy is performed is coded. In the case of intra block copy, encoding information such as a merge index in merge mode, a prediction block vector index in non-merge mode, a difference block vector, etc. is encoded according to a prescribed syntax (syntax rules for encoded bitstreams), and A coded bit string of 1 is generated. In the case of inter prediction (PRED_INTER), information about the flag to determine whether it is in merge mode, sub-block merge flag, merge index in case of merge mode, inter prediction mode if not in merge mode, predicted motion vector index, differential motion vector , and the sub-block prediction motion vector flag, etc., are encoded according to a prescribed syntax (syntax rules for encoded bitstreams) to be described later to generate a first encoded bitstream. In addition, bit string encoding section 108 entropy-encodes the orthogonally transformed and quantized residual signal according to a prescribed syntax to generate a second encoded bit string. The first encoded bit stream and the second encoded bit stream are multiplexed according to a prescribed syntax, and a bit stream is output.

The inverse quantization/inverse orthogonal transform unit 109 performs inverse quantization and inverse orthogonal transform on the orthogonal transform/quantized residual signal supplied from the orthogonal transform/quantization unit 107 to calculate a residual signal, and decodes the residual signal. It is supplied to the image signal superimposing unit 110 .

The decoded image signal superimposition unit 110 superimposes the prediction image signal determined by the prediction method determination unit 105 and the residual signal inversely quantized and inverse orthogonally transformed by the inverse quantization/inverse orthogonal transformation unit 109 to generate a decoded image. is generated and stored in the decoded image memory 104 . Note that the decoded image may be stored in the decoded image memory 104 after being subjected to filtering processing for reducing distortion such as block distortion due to encoding.

The coding information storage memory 111 stores coding information such as the prediction mode (inter prediction or intra prediction) determined by the prediction method determination unit 105 . The coding information stored in the coding information storage memory 111 includes, in the case of inter prediction, the determined motion vector, reference list, and reference index; Coding information of information indicating whether or not (sub-block merge flag), inter prediction mode in case of motion vector predictor mode of inter prediction, motion vector predictor index, reference index of L0 and L1, differential motion vector, sub-block mode Information indicating whether or not (sub-block prediction motion vector flag), in the case of intra prediction, the determined intra prediction mode, and the like. Construction of the history candidate list managed by the encoded information storage memory 111 will be described later.

FIG. 2 is a block diagram showing the configuration of a video decoding device according to an embodiment of the present invention corresponding to the video encoding device of FIG. The video decoding device of the embodiment includes a bit string decoding unit 201, a block division unit 202, an inter prediction unit 203, an intra prediction unit 204, an encoded information storage memory 205, an inverse quantization/inverse orthogonal transformation unit 206, a decoded image signal A superimposing unit 207 and a decoded image memory 208 are provided.

The decoding process of the video decoding device in FIG. 2 corresponds to the decoding process provided inside the video encoding device in FIG. The components of the inverse orthogonal transform unit 206, the decoded image signal superimposition unit 207, and the decoded image memory 208 are the inverse quantization/inverse orthogonal transform unit 109, the decoded image signal superimposition unit 110, and the It has a function corresponding to each configuration of the encoded information storage memory 111 and the decoded image memory 104 .

The bitstream supplied to the bitstream decoding unit 201 is separated according to a prescribed syntax rule. The separated first encoded bit stream is decoded to obtain sequences, pictures, slices, information in units of encoded blocks, and encoded information in units of encoded blocks. Specifically, the prediction mode PredMode and the division mode PartMode for determining inter prediction (PRED_INTER) or intra prediction (PRED_INTRA) are decoded in coding block units. In the case of intra prediction (PRED_INTRA), decode a flag (pred_mode_ibc_flag) for determining whether it is an intra block copy. In the case of intra block copy, encoded information such as the merge index if in merge mode, the prediction block vector index if not in merge mode, the difference block vector, etc. The coding information is supplied to the inter prediction section 203 or intra prediction section 204 and the coding information storage memory 205 . In the case of inter prediction (PRED_INTER), flag to determine whether it is merge mode, merge index in case of merge mode, sub-block merge flag, inter prediction mode in case of motion vector predictor mode, motion vector predictor index, differential motion It decodes coded information about vectors, sub-block predicted motion vector flags, etc. according to a specified syntax described later, and supplies the coded information to the inter predictor 203 or intra predictor 204 and the coded information storage memory 205 . The separated second encoded bit string is decoded to calculate an orthogonally transformed and quantized residual signal, and the orthogonally transformed and quantized residual signal is supplied to the inverse quantization and inverse orthogonal transformation section 206 .

When the prediction mode PredMode of the encoding block to be processed is inter prediction (PRED_INTER) and motion vector prediction mode, the inter prediction unit 203 predicts the code of the already decoded image signal stored in the encoding information storage memory 205. Using the transformation information, a plurality of motion vector predictor candidates are derived and registered in a motion vector predictor candidate list described later, and bit string decoding is performed from among the plurality of motion vector predictor candidates registered in the motion vector predictor candidate list A motion vector predictor corresponding to a motion vector predictor index decoded and supplied by the unit 201 is selected, a motion vector is calculated from the differential vector decoded by the bit string decoding unit 201 and the selected motion vector predictor, and other encoding is performed. It is stored in the encoded information storage memory 205 together with the information. The coding information of the coding block supplied and stored here includes flags predFlagL0[xP][yP], predFlagL1[xP] indicating whether to use prediction mode PredMode, partition mode PartMode, L0 prediction, and L1 prediction. [yP], reference indices refIdxL0[xP][yP], refIdxL1[xP][yP] of L0, L1, motion vectors mvL0[xP][yP], mvL1[xP][yP] of L0, L1, etc. . Here, xP and yP are indices indicating the position of the upper left pixel of the coding block in the picture. When the prediction mode PredMode is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the flag predFlagL0 indicating whether to use L0 prediction is 1, and the flag predFlagL1 indicates whether to use L1 prediction. is 0. When the inter prediction mode is L1 prediction (Pred_L1), the flag predFlagL0 indicating whether to use L0 prediction is 0, and the flag predFlagL1 indicating whether to use L1 prediction is 1. When the inter prediction mode is bi-prediction (Pred_BI), the flag predFlagL0 indicating whether to use L0 prediction and the flag predFlagL1 indicating whether to use L1 prediction are both 1. Furthermore, when the prediction mode PredMode of the encoding block to be processed is inter prediction (PRED_INTER) and merge mode, merge candidates are derived. A plurality of merging candidates are derived using the coding information of already decoded coding blocks stored in the coding information storage memory 205 and registered in a merge candidate list, which will be described later. A merge candidate corresponding to the merge index decoded and supplied by the bit string decoding unit 201 is selected from among the plurality of merge candidates, and a flag indicating whether to use the L0 prediction and L1 prediction of the selected merge candidate. predFlagL0[xP][yP], predFlagL1[xP][yP], L0, L1 reference index refIdxL0[xP][yP], refIdxL1[xP][yP], L0, L1 motion vector mvL0[xP][yP ], mvL1[xP][yP], etc. are stored in the encoded information storage memory 205 . Here, xP and yP are indices indicating the position of the upper left pixel of the coding block in the picture. The detailed configuration and operation of the inter prediction unit will be described later.

The intra prediction unit 204 performs intra prediction when the prediction mode PredMode of the encoding block to be processed is intra prediction (PRED_INTRA). The encoded information decoded by the bit string decoding unit 201 includes an intra prediction mode, and a predicted image signal is obtained by intra prediction from the decoded image signal stored in the decoded image memory 208 according to the intra prediction mode. is generated, and the predicted image signal is supplied to the decoded image signal superimposing unit 207 . Since the intra prediction unit 204 corresponds to the intra prediction unit 103 of the image encoding device 100, it performs the same processing as the intra prediction unit 103.

The inverse quantization/inverse orthogonal transformation unit 206 performs inverse orthogonal transformation and inverse quantization on the orthogonally transformed/quantized residual signal decoded by the bit stream decoding unit 201, and performs inverse orthogonal transformation/inverse quantization. to obtain the residual signal.

The decoded image signal superimposing unit 207 performs inverse orthogonal transform/transform/ The decoded image signal is decoded by superimposing it with the inverse quantized residual signal and stored in the decoded image memory 208 . When storing the decoded image in the decoded image memory 208, the decoded image may be stored in the decoded image memory 208 after being subjected to a filtering process for reducing block distortion due to encoding.

Next, the operation of the block dividing section 101 in the image encoding device 100 will be described. FIG. 3 is a flowchart illustrating the operation of dividing an image into treeblocks and subdividing each treeblock. First, an input image is divided into tree blocks of a predetermined size (step S1001). Each treeblock is scanned in a predetermined order, that is, in raster scan order (step S1002), and the inside of the treeblock to be processed is divided (step S1003).

FIG. 7 is a flow chart showing the detailed operation of the division processing in step S1003. First, it is determined whether or not to divide the block to be processed into four (step S1101).

When it is determined that the block to be processed is to be divided into four, the block to be processed is divided into four (step S1102). Each block obtained by dividing the block to be processed is scanned in the order of Z scanning, that is, upper left, upper right, lower left, and lower right (step S1103). FIG. 5 shows an example of the Z scan order, and 601 in FIG. 6 shows an example in which the block to be processed is divided into four. Numbers 0 to 3 in 601 in FIG. 6 indicate the order of processing. Then, the flowchart of FIG. 7 is recursively called for each block divided in step S1101.

If it is determined that the block to be processed is not divided into 4, it is divided into 2-3 (step S1105).

FIG. 8 is a flow chart showing the detailed operation of the 2-3 division processing in step S1105. First, it is determined whether or not to divide the block to be processed into 2-3, that is, whether to divide into 2 or 3 (step S1201).

If it is determined not to divide the block to be processed into 2-3, that is, if it is determined not to be divided, the division is terminated (step S1211), and the block in the upper layer is returned to.

If it is determined to divide the block to be processed into 2 or 3, it is determined whether to further divide the block to be processed into two (step S1202).

If the block to be processed is determined to be divided into two, it is determined whether to divide the block to be processed vertically (step S1203), and based on the result, the block to be processed is vertically divided (step S1204). Alternatively, the block to be processed is horizontally divided (step S1205). As a result of step S1204, the block to be processed is divided into two vertically as indicated by 602 in FIG. 6, and as a result of step S1205, the block to be processed is divided into two horizontally as indicated by 604 in FIG. be done.

If it is determined in step S1202 that the block to be processed is not to be divided into two, that is, if it is determined to be divided into three, it is determined whether or not to divide the block to be processed in the vertical direction (step S1206). Based on this, the block to be processed is divided vertically (step S1207) or horizontally (step S1208). As a result of step S1207, the block to be processed is vertically divided into three parts as indicated by 603 in FIG. be done.

After executing any one of steps S1204 to S1205, each block obtained by dividing the block to be processed is scanned from left to right and from top to bottom (step S1209). Numbers 0 to 3 in 602 to 605 in FIG. 6 indicate the order of processing. For each divided block, the division process 2-3 in the flow chart of FIG. 8 is recursively executed (step S1210).

In the recursive block division described here, necessity of division may be restricted by the number of divisions, the size of the block to be processed, or the like. Information that limits whether or not division is necessary may be implemented by a configuration in which information is not transmitted by prior agreement between the encoding device and the decoding device, or the coding device may limit whether or not division is necessary. The information may be determined and recorded in the encoded bit string to be transmitted to the decoding device.

Here, when a certain block is divided, the block before division is called a parent block, and each block after division is called a child block.

Next, the operation of the block dividing section 202 in the image decoding device 200 will be described. The block dividing unit 202 divides the treeblocks in the same processing procedure as the block dividing unit 101 of the image encoding device 100 . However, the block division unit 101 of the image encoding device 100 applies optimization techniques such as estimation of the optimum shape by image recognition and distortion rate optimization to determine the optimum block division shape, whereas the image decoding device The block division unit 202 in 200 is different in that the block division shape is determined by decoding the block division information recorded in the encoded bit stream.

FIG. 9 shows the syntax (syntax rules for encoded bit strings) relating to block division in the first embodiment. coding_quadtree() represents the syntax for dividing a block into four, and multi_type_tree() represents the syntax for dividing the block into two or three. qt_split is a flag indicating whether to divide the block into four or not. When the block is divided into four, qt_split=1, and when not divided into four, qt_split=0. When dividing into four (qt_split=1), each block divided into four is recursively divided into four (coding_quadtree(0), coding_quadtree(1), coding_quadtree(2), coding_quadtree(3)). When not splitting into 4 (qt_split=0), the subsequent splitting is determined according to multi_type_tree(). mtt_split is a flag indicating whether or not to further split. For further splitting (mtt_split=1), refer to mtt_split_vertical, which is a flag indicating whether to split vertically or horizontally, and mtt_split_binary, which is a flag for determining whether to split into two or three. mtt_split_vertical=1 indicates splitting in the vertical direction, and mtt_split_vertical=0 indicates splitting in the horizontal direction. mtt_split_binary=1 indicates splitting into two, and mtt_split_binary=0 indicates splitting into three. Perform hierarchical block splitting by recursively calling multi_type_tree until mtt_split=0.

<Intra prediction>
The intra prediction method according to the embodiment is implemented in the intra prediction section 103 of the video encoding device in FIG. 1 and the intra prediction section 203 of the video decoding device in FIG.

An intra-prediction method according to an embodiment will be described with reference to the drawings. The intra-prediction method is implemented in both encoding and decoding processes in units of encoded blocks.

<Explanation of Intra Predictor 103 on Encoding Side>
FIG. 41 is a diagram showing the detailed configuration of the intra prediction unit 103 of the moving picture coding apparatus of FIG. The normal intra prediction unit 351 generates a predicted image signal by normal intra prediction from decoded pixels adjacent to the encoding block to be processed, selects a suitable intra prediction mode from among a plurality of intra prediction modes, and selects The selected intra prediction mode and the predicted image signal corresponding to the selected intra prediction mode are supplied to the prediction method determination unit 105 . FIG. 10 shows an example of normal intra prediction. FIG. 10(a) shows the correspondence between the prediction direction of normal intra prediction and the intra prediction mode number. For example, intra-prediction mode 50 produces intra-predicted images by copying pixels vertically. Intra-prediction mode 1 is a DC mode, and is a mode in which all pixel values of a block to be processed are average values of reference pixels. Intra prediction mode 0 is a planar mode, and is a mode in which a two-dimensional intra prediction image is created from reference pixels in the vertical and horizontal directions. FIG. 10B is an example of generating an intra-prediction image in intra-prediction mode 40. FIG. The value of the reference pixel in the direction indicated by the intra prediction mode is copied to each pixel of the block to be processed. When the reference pixel in the intra prediction mode is not at the integer position, the reference pixel value is determined by interpolation from the reference pixel values at the surrounding integer positions.

The intra-block copy prediction unit 352 acquires the decoded region of the same image signal as the encoding block to be processed from the decoded image memory 104, generates a prediction image signal by intra-block copy processing, and predicts the prediction method determination unit 105. supply to A detailed configuration and processing of the intra block copy prediction unit 352 will be described later.

<Description of Intra Predictor 204 on the Decoding Side>
FIG. 42 is a diagram showing the detailed configuration of the intra prediction unit 204 of the video decoding device of FIG.

The normal intra prediction unit 361 generates a predicted image signal by normal intra prediction from decoded pixels adjacent to the encoding block to be processed, selects a suitable intra prediction mode from among a plurality of intra prediction modes, and selects A predicted image signal corresponding to the selected intra prediction mode and the selected intra prediction mode is obtained. This predicted image signal is supplied to the decoded image signal superimposing unit 207 via the switch 364 . Since the processing of the normal intra prediction unit 361 in FIG. 42 corresponds to the normal intra prediction unit 351 in FIG. 41, detailed description thereof will be omitted.

The intra block copy prediction unit 362 acquires the decoded area of the same image signal as the encoding block to be processed from the decoded image memory 208, and obtains a predicted image signal by intra block copy processing. This predicted image signal is supplied to the decoded image signal superimposing unit 207 via the switch 364 . A detailed configuration and processing of the intra block copy prediction unit 362 will be described later.

<Inter Prediction>
The inter prediction method according to the embodiment is implemented in the inter prediction section 102 of the video encoding device in FIG. 1 and the inter prediction section 203 of the video decoding device in FIG.

An inter-prediction method according to an embodiment will be described with reference to the drawings. The inter-prediction method is implemented in both encoding and decoding processes in units of encoded blocks.

<Description of inter prediction unit 102 on the encoding side>
FIG. 16 is a diagram showing the detailed configuration of the inter prediction unit 102 of the video encoding device of FIG. A normal motion vector predictor mode deriving unit 301 derives a plurality of normal motion vector predictor candidates, selects a motion vector predictor, and calculates a differential vector from the detected motion vector. The detected inter prediction mode, reference index, motion vector, and calculated difference vector are inter prediction information for the normal predicted motion vector mode. This inter prediction information is supplied to the inter prediction mode determination unit 305 . The detailed configuration and processing of the normal motion vector predictor mode derivation unit 301 will be described later.

A normal merge mode derivation unit 302 derives a plurality of normal merge candidates, selects a normal merge candidate, and obtains inter prediction information in the normal merge mode. This inter prediction information is supplied to the inter prediction mode determination unit 305 . The detailed configuration and processing of the normal merge mode derivation unit 302 will be described later.

A sub-block predictor motion vector mode deriving unit 303 derives a plurality of sub-block predictor motion vector candidates, selects a sub-block predictor motion vector, and calculates a difference vector from the detected motion vector. The detected inter prediction mode, reference index, motion vector, and calculated difference vector are inter prediction information for the normal predicted motion vector mode. This inter prediction information is supplied to the inter prediction mode determination unit 305 . The detailed configuration and processing of the sub-block predicted motion vector mode derivation unit 303 will be described later.

A sub-block merging mode derivation unit 304 derives a plurality of sub-block merging candidates, selects a sub-block merging candidate, and obtains inter-prediction information for the sub-block merging mode. This inter prediction information is supplied to the inter prediction mode determination unit 305 . A detailed configuration and processing of the sub-block merge mode derivation unit 304 will be described later.

Based on the inter prediction information supplied from the normal prediction motion vector mode derivation unit 301, the normal merge mode derivation unit 302, the sub-block prediction motion vector mode derivation unit 303, and the sub-block merge mode derivation unit 304, the inter prediction mode determination unit 305 , determine the inter-prediction mode. The inter prediction information according to the determination result is supplied from the inter prediction mode determination unit 305 to the motion compensation prediction unit 306 .

Based on the determined inter prediction information, the motion compensation prediction unit 306 performs inter prediction on the reference image signal stored in the decoded image memory 104 . Detailed configuration and processing will be described later.

<Description of Inter Predictor 203 on the Decoding Side>
FIG. 22 is a diagram showing a detailed configuration of the inter prediction unit 203 of the video decoding device of FIG. 2. As shown in FIG.

A normal motion vector predictor mode deriving unit 401 derives a plurality of normal motion vector predictor candidates, selects a motion vector predictor, and calculates a differential vector from the detected motion vector. The detected inter prediction mode, reference index, motion vector, and difference vector are inter prediction information for the normal predicted motion vector mode. This inter prediction information is supplied to the motion compensation prediction section 406 via the switch 408 . The detailed configuration and processing of the normal motion vector predictor mode derivation unit 401 will be described later.

A normal merge mode derivation unit 402 derives a plurality of normal merge candidates, selects a normal merge candidate, and obtains inter prediction information in the normal merge mode. This inter prediction information is supplied to the motion compensation prediction section 406 via the switch 408 . The detailed configuration and processing of the normal merge mode derivation unit 402 will be described later.

A sub-block predictor motion vector mode derivation unit 403 derives a plurality of sub-block predictor motion vector candidates, selects a sub-block predictor motion vector, and calculates a difference vector from the detected motion vector. The detected inter prediction mode, reference index, motion vector, and calculated difference vector are inter prediction information for the normal predicted motion vector mode. This inter prediction information is supplied to the motion compensation prediction section 406 via the switch 408 .

A sub-block merging mode deriving unit 404 derives a plurality of sub-block merging candidates, selects a sub-block merging candidate, and obtains inter-prediction information for the sub-block merging mode. This inter prediction information is supplied to the motion compensation prediction section 406 via the switch 408 . Based on the determined inter prediction information, the motion compensation prediction unit 406 performs inter prediction on the reference image signal stored in the decoded image memory 208 . The detailed configuration and processing are the same as those on the encoding side.

<Normal predicted motion vector mode derivation unit (normal AMVP)>
The normal motion vector predictor mode deriving unit 301 in FIG. A vector detection unit 326 , a motion vector predictor candidate selection unit 327 and a motion vector subtraction unit 328 are included.

The normal motion vector predictor mode deriving unit 401 in FIG. A vector candidate selection unit 426 and a motion vector addition unit 427 are included.

Processing procedures of the normal predicted motion vector mode deriving unit 301 on the encoding side and the normal predicted motion vector mode deriving unit 401 on the decoding side will be described with reference to the flowcharts of FIGS. 19 and 25, respectively. FIG. 19 is a flowchart showing the normal predicted motion vector mode derivation processing procedure by the normal motion vector mode derivation unit 301 on the encoding side, and FIG. 25 is the normal predicted motion vector mode derivation processing by the normal motion vector mode derivation unit 401 on the decoding side. It is a flow chart which shows a procedure.

<Normal predicted motion vector mode derivation unit (normal AMVP): description on the encoding side>
A normal motion vector prediction mode derivation processing procedure on the encoding side will be described with reference to FIG. In the explanation of the processing procedure in FIG. 19, the term "motion vector" in the specification corresponds to the term "normal motion vector" in FIG.

First, the normal motion vector detection unit 326 detects a normal motion vector for each inter prediction mode and reference index (step S100 in FIG. 19).

Subsequently, a spatial motion vector predictor candidate deriving unit 321, a temporal motion vector predictor candidate deriving unit 322, a historical motion vector predictor candidate deriving unit 323, a motion vector predictor candidate supplementing unit 325, a motion vector predictor candidate selecting unit 327, and a motion vector subtracting unit. At 328, differential motion vectors of motion vectors used for inter prediction in normal motion vector predictor mode are calculated for each of L0 and L1 (steps S101 to S106 in FIG. 19). Specifically, when the prediction mode PredMode of the block to be processed is inter prediction (MODE_INTER) and the inter prediction mode is L0 prediction (Pred_L0), the L0 motion vector predictor candidate list mvpListL0 is calculated and the motion vector predictor mvpL0 is selected. Then, the difference motion vector mvdL0 of the motion vector mvL0 of L0 is calculated. When the inter prediction mode of the block to be processed is L1 prediction (Pred_L1), the L1 motion vector predictor candidate list mvpListL1 is calculated, the motion vector predictor mvpL1 is selected, and the differential motion vector mvdL1 of the L1 motion vector mvL1 is calculated. . When the inter prediction mode of the block to be processed is bi-prediction (Pred_BI), both L0 prediction and L1 prediction are performed, L0 motion vector predictor candidate list mvpListL0 is calculated, L0 motion vector predictor mvpL0 is selected, and L0 Calculates the differential motion vector mvdL0 of the motion vector mvL0 of L1, calculates the motion vector predictor candidate list mvpListL1 of L1, calculates the predicted motion vector mvpL1 of L1, and calculates the differential motion vector mvdL1 of the motion vector mvL1 of L1. do.

Differential motion vector calculation processing is performed for each of L0 and L1, and the processing is common to both L0 and L1. Therefore, L0 and L1 are represented as common LX in the following description. X is 0 in the process of calculating the differential motion vector of L0, and X is 1 in the process of calculating the differential motion vector of L1. Also, when referring to the information of the other list instead of LX during the process of calculating the differential motion vector of LX, the other list is represented as LY.

If the LX motion vector mvLX is used (step S102 in FIG. 19: YES), the LX motion vector predictor candidates are calculated and the LX motion vector predictor candidate list mvpListLX is constructed (step S103 in FIG. 19). A spatial motion vector predictor candidate deriving unit 321, a temporal motion vector predictor candidate deriving unit 322, a historical motion vector predictor candidate deriving unit 323, and a motion vector predictor candidate supplementing unit 325 in the normal motion vector predictor mode deriving unit 301 generate multiple predicted motions. A motion vector predictor candidate list mvpListLX is constructed by deriving vector candidates. A detailed processing procedure of step S103 in FIG. 19 will be described later using the flowchart in FIG.

Subsequently, the motion vector predictor candidate selection unit 327 selects the LX motion vector predictor mvpLX from the LX motion vector predictor candidate list mvpListLX (step S104 in FIG. 19). A motion vector difference between the motion vector mvLX and each motion vector predictor candidate mvpListLX[i] stored in the motion vector predictor candidate list mvpListLX is calculated. A code amount when the differential motion vectors are encoded is calculated for each element of the motion vector predictor candidate list mvpListLX. Then, among the elements registered in the motion vector predictor candidate list mvpListLX, the motion vector predictor candidate mvpListLX[i] having the minimum code amount for each motion vector predictor candidate is selected as the motion vector predictor mvpLX. Get index i. If there are multiple motion vector predictor candidates with the smallest amount of generated code in the motion vector predictor candidate list mvpListLX, the motion vector predictor candidate list mvpListLX with a small index i is indicated by a small number. , is selected as the optimal motion vector predictor mvpLX, and its index i is obtained.

Subsequently, the motion vector subtraction unit 328 subtracts the selected predicted motion vector mvpLX of LX from the motion vector mvLX of LX,
mvdLX = mvLX - mvpLX
, the differential motion vector mvdLX of LX is calculated (step S105 in FIG. 19).

<Normal predicted motion vector mode derivation unit (normal AMVP): description on the decoding side>
Next, the decoding-side normal predicted motion vector mode processing procedure will be described with reference to FIG. On the decoding side, the spatial motion vector predictor candidate deriving unit 421, the temporal motion vector predictor candidate deriving unit 422, the historical motion vector predictor candidate deriving unit 423, and the motion vector predictor candidate supplementing unit 425 use inter prediction in normal motion vector predictor mode. A motion vector is calculated for each of L0 and L1 (steps S201 to S206 in FIG. 25). Specifically, when the prediction mode PredMode of the block to be processed is inter prediction (MODE_INTER) and the inter prediction mode of the block to be processed is L0 prediction (Pred_L0), the L0 motion vector predictor candidate list mvpListL0 is calculated and the predicted motion Select the vector mvpL0 and calculate the motion vector mvL0 of L0. When the inter prediction mode of the block to be processed is L1 prediction (Pred_L1), the L1 motion vector predictor candidate list mvpListL1 is calculated, the motion vector predictor mvpL1 is selected, and the L1 motion vector mvL1 is calculated. When the inter prediction mode of the block to be processed is bi-prediction (Pred_BI), both L0 prediction and L1 prediction are performed, L0 motion vector predictor candidate list mvpListL0 is calculated, L0 motion vector predictor mvpL0 is selected, and L0 L1's motion vector mvL0 is calculated, L1's motion vector predictor candidate list mvpListL1 is calculated, L1's predicted motion vector mvpL1 is calculated, and L1's motion vector mvL1 is calculated.

Similar to the encoding side, the decoding side also performs motion vector calculation processing for each of L0 and L1, but the processing is common to both L0 and L1. Therefore, L0 and L1 are represented as common LX in the following description. LX represents an inter-prediction mode used for inter-prediction of a coding block to be processed. X is 0 in the process of calculating the motion vector of L0, and X is 1 in the process of calculating the motion vector of L1. Also, when referring to the information of another reference list instead of the same reference list as that of LX to be calculated during the process of calculating the motion vector of LX, the other reference list is represented as LY.

If the LX motion vector mvLX is to be used (step S202 in FIG. 25: YES), LX motion vector predictor candidates are calculated to construct the LX motion vector predictor candidate list mvpListLX (step S203 in FIG. 25). A spatial motion vector predictor candidate deriving unit 421, a temporal motion vector predictor candidate deriving unit 422, a historical motion vector predictor candidate deriving unit 423, and a motion vector predictor candidate supplementing unit 425 in the normal motion vector predictor mode deriving unit 401 generate a plurality of predicted motions. Vector candidates are calculated and a motion vector predictor candidate list mvpListLX is constructed. A detailed processing procedure of step S203 in FIG. 25 will be described later using the flowchart in FIG.

Subsequently, the motion vector predictor candidate selection unit 426 selects a motion vector predictor candidate mvpListLX[mvpIdxLX] corresponding to the motion vector predictor index mvpIdxLX decoded and supplied by the bit string decoding unit 201 from the motion vector predictor candidate list mvpListLX. fetched as the predicted motion vector mvpLX (step S204 in FIG. 25).

Subsequently, the motion vector addition unit 427 adds the differential motion vector mvdLX of LX and the predicted motion vector mvpLX of LX, which are decoded and supplied by the bit string decoding unit 201, and
mvLX = mvpLX + mvdLX
, the motion vector mvLX of LX is calculated (step S205 in FIG. 25).

<Normal Predictive Motion Vector Mode Derivation Unit (Normal AMVP): Motion Vector Prediction Method>
FIG. 20 shows a normal predicted motion vector having functions common to the normal predicted motion vector mode derivation unit 301 of the video encoding device and the normal predicted motion vector mode derivation unit 401 of the video decoding device according to the embodiment of the present invention. 4 is a flow chart showing a processing procedure of mode derivation processing;

The normal motion vector predictor mode deriving unit 301 and the normal motion vector predictor mode deriving unit 401 have a motion vector predictor candidate list mvpListLX. The motion vector predictor candidate list mvpListLX has a list structure, and is provided with a motion vector predictor index indicating the location in the motion vector predictor candidate list and a storage area for storing the motion vector predictor candidate corresponding to the index as an element. The number of the motion vector predictor index starts from 0, and the motion vector predictor candidates are stored in the storage area of the motion vector predictor candidate list mvpListLX. In this embodiment, the motion vector predictor candidate list mvpListLX can register at least two motion vector predictor candidates (inter prediction information). Furthermore, 0 is set to a variable numCurrMvpCand indicating the number of motion vector predictor candidates registered in the motion vector predictor candidate list mvpListLX.

Spatial motion vector predictor candidate deriving units 321 and 421 derive a motion vector predictor candidate from the left adjacent block. In this processing, a flag availableFlagLXA indicating whether or not the motion vector predictor candidate of the block (A0 or A1) adjacent to the left side is available, a motion vector mvLXA, and a reference index refIdxA are derived, and mvLXA is added to the motion vector predictor candidate list mvpListLX. (step S301 in FIG. 20). Note that X is 0 when L0 and X is 1 when L1 (same below). Subsequently, the spatial motion vector predictor candidate deriving units 321 and 421 derive a motion vector predictor candidate from the upper adjacent block (B0, B1 or B2). In this process, a flag availableFlagLXB indicating whether or not the motion vector predictor candidate of the block adjacent to the upper side is available, a motion vector mvLXB, and a reference index refIdxB are derived. Add to the candidate list mvpListLX (step S302 in FIG. 20). The processes of steps S301 and S302 in FIG. 20 are common except that the positions and numbers of adjacent blocks to be referred to are different, and flag availableFlagLXN indicating whether or not the motion vector predictor candidate of the coding block is available, and motion vector mvLXN. , a reference index refIdxN (N is A or B, and so on).

Subsequently, the temporal motion vector predictor candidate deriving units 322 and 422 derive candidate motion vector predictors from the encoding blocks in the pictures whose time is different from that of the current picture to be processed. In this processing, a flag availableFlagLXCol, which indicates whether or not a motion vector predictor candidate for a coded block in a picture at a different time is available, a motion vector mvLXCol, a reference index refIdxCol, and a reference list listCol are derived, and mvLXCol is derived as a motion vector predictor candidate. Add to list mvpListLX (step S303 in FIG. 20). A detailed description of the derivation processing procedure in step S303 will be omitted.

It is assumed that the processing of the temporal motion vector predictor candidate deriving units 322 and 422 can be omitted for each sequence (SPS), picture (PPS), or slice.

Subsequently, the historical motion vector predictor candidate deriving units 323 and 423 add the historical motion vector predictor candidates registered in the historical motion vector predictor candidate list HmvpCandList to the motion vector predictor candidate list mvpListLX. (Step S304 in FIG. 20). Details of the registration processing procedure in step S304 will be described later using the flowchart of FIG.

Subsequently, the motion vector predictor candidate supplementing units 325 and 425 add motion vectors of predetermined values such as (0, 0) until the motion vector predictor candidate list mvpListLX is filled (S305 in FIG. 20).

<Normal merge mode derivation unit (normal merge)>
The normal merge mode derivation unit 302 in FIG. including.

The normal merge mode derivation unit 402 in FIG. 24 includes a spatial merge candidate derivation unit 441, a temporal merge candidate derivation unit 442, an average merge candidate derivation unit 444, a history merge candidate derivation unit 445, a merge candidate supplement unit 446, and a merge candidate selection unit 447. including.

FIG. 21 shows the procedure of normal merge mode derivation processing having functions common to the normal merge mode derivation unit 302 of the video encoding device and the normal merge mode derivation unit 402 of the video decoding device according to the embodiment of the present invention. It is a flow chart explaining.

The various processes will be described below in order. In the following description, unless otherwise specified, the slice type slice_type is B slice, but it can also be applied to P slice. However, when the slice type slice_type is a P slice, there is only L0 prediction (Pred_L0) as an inter prediction mode, and there is no L1 prediction (Pred_L1) or bi-prediction (Pred_BI), so processing related to L1 can be omitted.

The normal merge mode derivation unit 302 and the normal merge mode derivation unit 402 have a merge candidate list mergeCandList. The merge candidate list mergeCandList has a list structure, and is provided with a merge index indicating the location in the merge candidate list and a storage area for storing the merge candidate corresponding to the index as an element. The number of the merge index starts from 0, and the merge candidates are stored in the storage area of the merge candidate list mergeCandList. In the subsequent processing, merge candidates with merge index i registered in the merge candidate list mergeCandList are represented by mergeCandList[i]. In this embodiment, the merge candidate list mergeCandList can register at least six merge candidates (inter prediction information). Furthermore, 0 is set to the variable numCurrMergeCand indicating the number of merge candidates registered in the merge candidate list mergeCandList.

The spatial merging candidate deriving unit 341 and the spatial merging candidate deriving unit 441 perform processing based on the encoding information stored in the encoding information storage memory 111 of the video encoding device or the encoding information storage memory 205 of the video decoding device. Spatial merge candidates A and B are derived from the blocks adjacent to the left and upper sides of the target block, and the derived spatial merge candidates are registered in the merge candidate list mergeCandList (step S401 in FIG. 21). Now define N to denote either the spatial merge candidates A, B or the temporal merge candidates Col. Flag availableFlagN indicating whether or not inter prediction information of block N can be used as spatial merge candidate N, L0 reference index refIdxL0N and L1 reference index refIdxL1N of spatial merge candidate N, L0 indicating whether or not L0 prediction is performed A prediction flag predFlagL0N, an L1 prediction flag predFlagL1N indicating whether L1 prediction is performed, a motion vector mvL0N of L0, and a motion vector mvL1N of L1 are derived. However, in the present embodiment, merging candidates are derived without referring to other encoding blocks included in the block including the encoding block to be processed. It does not derive spatial merge candidates that

Subsequently, the temporal merge candidate derivation unit 342 and the temporal merge candidate derivation unit 442 derive temporal merge candidates from pictures at different times, and register the derived temporal merge candidates in the merge candidate list mergeCandList (see FIG. 21). step S402). A flag availableFlagCol indicating whether the temporal merge candidate is available, an L0 prediction flag predFlagL0Col indicating whether L0 prediction of the temporal merge candidate is performed, and an L1 prediction flag predFlagL1Col indicating whether L1 prediction is performed, and L0 motion vector mvL0Col of L1 and motion vector mvL1Col of L1 are derived. Description of the detailed processing procedure of step S402 is omitted.

It is assumed that the processing of the temporal merge candidate derivation unit 342 and the temporal merge candidate derivation unit 442 can be omitted for each sequence (SPS), picture (PPS), or slice.

Subsequently, the history merge candidate derivation unit 345 and the history merge candidate derivation unit 445 add the history motion vector predictor candidates registered in the history motion vector predictor candidate list HmvpCandList to the merge candidate list mergeCandList (step S403 in FIG. 21). . A detailed processing procedure of step S403 will be described later using the flowchart of FIG.

Subsequently, the average merge candidate derivation unit 344 and the average merge candidate derivation unit 444 derive average merge candidates from the merge candidate list mergeCandList and register the derived average merge candidates in the merge candidate list mergeCandList (step in FIG. 21). S404). A detailed processing procedure of step S404 will be described later using the flowchart of FIG.

Subsequently, in the merge candidate supplementing unit 346 and the merge candidate supplementing unit 446, when the number of merge candidates numCurrMergeCand registered in the merge candidate list mergeCandList is smaller than the maximum number of merge candidates MaxNumMergeCand, the merge candidates are not registered in the merge candidate list mergeCandList. With the maximum number of merge candidates MaxNumMergeCand as the upper limit, additional merge candidates are derived and registered in the merge candidate list mergeCandList (step S405 in FIG. 21). With the maximum number of merge candidates MaxNumMergeCand as the upper limit, in P slices, merge candidates whose prediction mode is L0 prediction (Pred_L0) and whose motion vector has a value of (0, 0) with different reference indices are added. In the B slice, a merging candidate whose prediction mode is bi-prediction (Pred_BI) and whose motion vector has a value of (0, 0) with a different reference index is added.

Subsequently, the merge candidate selection unit 347 and the merge candidate selection unit 447 select merge candidates from the merge candidates registered in the merge candidate list mergeCandList. The merge candidate selection unit 347 on the encoding side selects a merge candidate by calculating the amount of code and the amount of distortion, and sends the merge index indicating the selected merge candidate and the inter prediction information of the merge candidate to the motion compensation prediction unit 306. supply. On the other hand, the decoding-side merge candidate selection unit 447 selects a merge candidate based on the decoded merge index, and supplies the selected merge candidate to the motion compensation prediction unit 406 .

<Update history motion vector predictor candidate list>
Next, a method for initializing and updating the history motion vector predictor candidate list HmvpCandList provided in the encoding information storage memory 111 on the encoding side and the encoding information storage memory 205 on the decoding side will be described in detail. FIG. 26 is a flowchart for explaining a history motion vector predictor candidate list initialization/update processing procedure.

In this embodiment, it is assumed that the history motion vector predictor candidate list HmvpCandList is updated by the encoding information storage memory 111 and the encoding information storage memory 205 . A history candidate list update unit may be installed in the inter prediction unit 102 and the inter prediction unit 203 to update the history motion vector predictor candidate list HmvpCandList.

The historical motion vector predictor candidate list HmvpCandList is initialized at the beginning of the slice, and the historical motion vector predictor candidate list HmvpCandList is updated on the encoding side when the prediction method determination unit 105 selects the normal vector predictor mode or the normal merge mode. On the decoding side, the history motion vector predictor candidate list HmvpCandList is updated when the inter prediction mode decoded by the bitstream decoding unit 201 is the normal vector predictor mode or the normal merge mode.

The inter prediction information used when inter prediction is performed in the normal vector predictor mode or the normal merge mode is registered in the history motion vector predictor candidate list HmvpCandList as the inter prediction information candidate hMvpCand. Inter prediction information candidate hMvpCand includes L0 reference index refIdxL0 and L1 reference index refIdxL1, L0 prediction flag predFlagL0 indicating whether L0 prediction is performed, L1 prediction flag predFlagL1 indicating whether L1 prediction is performed, A motion vector mvL0 of L0 and a motion vector mvL1 of L1 are included. Inter prediction information candidate If inter prediction information with the same value as hMvpCand exists, that element is deleted from the historical motion vector predictor candidate list HmvpCandList. On the other hand, if there is no inter prediction information with the same value as the inter prediction information candidate hMvpCand, the leading element of the historical motion vector predictor candidate list HmvpCandList is deleted, and the inter prediction information candidate Add hMvpCand.

The number of elements of the history motion vector predictor candidate list HmvpCandList provided in the encoding information storage memory 111 on the encoding side and the encoding information storage memory 205 on the decoding side of the present invention is six.

First, the history motion vector predictor candidate list HmvpCandList is initialized for each slice (step S2101 in FIG. 26). At the beginning of the slice, all elements of the historical motion vector predictor candidate list HmvpCandList are emptied, and the value of NumHmvpCand, the number of historical motion vector predictor candidates registered in the historical motion vector predictor candidate list HmvpCandList, is set to zero.

Although the historical motion vector predictor candidate list HmvpCandList is initialized in units of slices (first coded blocks in slices), it may be initialized in units of pictures, tiles, or treeblock rows.

Subsequently, the following updating process of the history motion vector predictor candidate list HmvpCandList is repeatedly performed for each encoded block in the slice (steps S2102 to S2107 in FIG. 26).

First, initialization is performed for each encoding block. A flag identicalCandExist indicating whether or not the same candidate exists is set to FALSE, and a deletion target index removeIdx is set to 0 (step S2103 in FIG. 26).

It is determined whether or not the inter prediction information candidate hMvpCand to be registered exists in the historical motion vector predictor candidate list HmvpCandList (step S2104 in FIG. 26). When the prediction method determination unit 105 on the encoding side determines the normal motion vector prediction mode or the normal merge mode, or when the bit stream decoding unit 201 on the decoding side decodes as the normal motion vector prediction mode or the normal merge mode, Let the inter prediction mode be hMvpCand. When the prediction method determination unit 105 on the encoding side determines the intra prediction mode, the sub-block motion vector prediction mode, or the sub-block merge mode, or when the bitstream decoding unit 201 on the decoding side selects the intra prediction mode or the sub-block prediction motion vector mode. Alternatively, when decoding is performed in the sub-block merge mode, the history motion vector predictor candidate list HmvpCandList is not updated, and there is no inter prediction information candidate hMvpCand to be registered. If there is no inter prediction information candidate hMvpCand to be registered, steps S2105 and S2106 are skipped (step S2104 in FIG. 26: NO). If there is an inter-prediction information candidate hMvpCand to be registered, the process from step S2105 is performed (step S2104 in FIG. 26: YES).

Next, it is determined whether or not each element of the historical motion vector predictor candidate list HmvpCandList includes the same element as the inter prediction information candidate hMvpCand to be registered (step S2105 in FIG. 26). FIG. 27 is a flow chart of this identical element confirmation processing procedure. If the value of the number of historical motion vector predictor candidates NumHmvpCand is 0 (step S2121 in FIG. 27: NO), the historical motion vector predictor candidate list HmvpCandList is empty and the same candidate does not exist, so steps S2122 to S2125 in FIG. 27 are skipped. , ends the same element confirmation processing procedure. If the value of the number of historical motion vector predictor candidates NumHmvpCand is greater than 0 (step S2121 in FIG. 27: YES), the processing in step S2123 is repeated until the historical motion vector predictor index hMvpIdx is from 0 to NumHmvpCand-1 (step in FIG. 27). S2122-S2125). First, it is compared whether or not the hMvpIdx-th element HmvpCandList[hMvpIdx] counting from 0 in the historical motion vector predictor candidate list is the same as the inter prediction information candidate hMvpCand (step S2123 in FIG. 27). If it is the same (step S2123 in FIG. 27: YES), the flag identicalCandExist indicating whether or not the same candidate exists is set to TRUE (true), the deletion target index removeIdx is set to the value of hMVpIndex, and the actual identity is set. End element confirmation processing. If they are not the same (step S2123 in FIG. 27: NO), hMvpIdx is incremented by 1, and if the historical motion vector index hMvpIdx is less than or equal to NumHmvpCand-1, the processes after step S2123 are performed (steps S2122 to S2125 in FIG. 27). .

Returning to the flowchart of FIG. 26 again, shift and addition processing of the elements of the history motion vector predictor candidate list HmvpCandList is performed (step S2106 of FIG. 26). FIG. 28 is a flowchart of the element shift/addition processing procedure of the history motion vector predictor candidate list HmvpCandList in step S2106 of FIG. First, it is determined whether to add a new element after removing the elements stored in the historical motion vector predictor candidate list HmvpCandList or to add a new element without removing the elements. Specifically, it is compared whether the flag identicalCandExist indicating whether or not the same candidate exists is TRUE (true) or whether NumHmvpCand is 6 (step S2141 in FIG. 28). If either the flag identicalCandExist indicating whether or not the same candidate exists is TRUE (true) or NumHmvpCand satisfies the condition of 6 (step S2141 in FIG. Remove existing elements and add new elements. Set the initial value of index i to the value of removeIdx + 1. The element shift processing in step S2143 is repeated from this initial value to NumHmvpCand. (Steps S2142 to S2144 in FIG. 28). By copying the element of HMVPCandList[i] to HMVPCandList[i-1], the element is shifted forward (step S2143 in FIG. 28), and i is incremented by 1 (steps S2142 to S2144 in FIG. 28). When the index i becomes NumHmvpCand+1 and the element shift processing in step S2143 is completed, the inter prediction information candidate hMvpCand is added to the end of the history motion vector predictor candidate list (step S2145 in FIG. 28). Here, the end of the historical motion vector predictor candidate list is the (NumHmvpCand-1)-th HMVPCandList[NumHmvpCand-1] counted from 0. This completes the element shift/addition process for the historical motion vector predictor candidate list HMVPCandList. On the other hand, if the flag identicalCandExist indicating whether or not the same candidate exists is TRUE (true) and NumHmvpCand does not meet the conditions of 6 (step S2141 in FIG. 28: NO), it is stored in the historical motion vector predictor candidate list HmvpCandList. The inter-prediction information candidate hMvpCand is added to the end of the historical motion vector predictor candidate list without removing the elements that are indicated (step S2146 in FIG. 28). Here, the end of the historical motion vector predictor candidate list is the NumHmvpCand-th HMVPCandList[NumHmvpCand] counted from 0. Also, NumHmvpCand is incremented by 1, and the element shift/addition processing of this historical motion vector predictor candidate list HMVPCandList is completed.

FIG. 31 is a diagram illustrating an example of update processing of the historical motion vector predictor list. When adding new inter prediction information when six elements (inter prediction information) are registered in the historical motion vector predictor candidate list HMVPCandList, each element of the historical motion vector predictor candidate list HMVPCandList and the new inter prediction information are added from the front. After comparing the prediction information (FIG. 31(a)), if the new inter prediction information has the same value as the third element HMVP2 from the top of the historical motion vector predictor candidate list HMVPCandList, Delete the element HMVP2, shift (copy) the backward elements HMVP3 to HMVP5 forward one by one, and add new inter prediction information to the end of the history motion vector predictor candidate list HMVPCandList (Fig. 31(b)). , the update of the history motion vector predictor candidate list HMVPCandList is completed (FIG. 31(c)).

<Historical Motion Vector Predictor Candidate Derivation Processing>
Next, the historical motion vector predictor candidate deriving unit 323 of the normal predictive motion vector mode deriving unit 301 on the encoding side and the historical motion vector predictor candidate deriving unit 423 of the normal predictive motion vector mode deriving unit 401 on the decoding side perform common processing. A method for deriving historical motion vector predictor candidates from the historical motion vector predictor candidate list HMVPCandList, which is the processing procedure of step S304 in FIG. 20, will be described in detail. FIG. 29 is a flowchart for explaining the historical motion vector predictor candidate derivation processing procedure.

If the number of current motion vector predictor candidates numCurrMvpCand is greater than or equal to the maximum number of elements (here, assumed to be 2) in the motion vector predictor candidate list mvpListLX, or if the value of the number of historical motion vector predictor candidates NumHmvpCand is 0 (step S2201 in FIG. 29: NO), the processing of steps S2202 to S2209 in FIG. 29 is omitted, and the history motion vector predictor candidate derivation processing procedure ends. If the number of current motion vector predictor candidates numCurrMvpCand is less than 2, which is the maximum number of elements in the motion vector predictor candidate list mvpListLX, and if the value of the number of historical motion vector predictor candidates NumHmvpCand is greater than 0 (step S2201 in FIG. 29: YES), the processing of steps S2202 to S2209 in FIG. 29 is performed.

Subsequently, the processing from steps S2203 to S2208 in FIG. 41 is repeated until the index i is from 1 to 4 or the number of historical motion vector predictor candidates NumHmvpCand, whichever is smaller (steps S2202 to S2209 in FIG. 29). If the number of current motion vector predictor candidates numCurrMvpCand is equal to or greater than 2, which is the maximum number of elements in the motion vector predictor candidate list mvpListLX (step S2203 in FIG. 29: NO), the processing from steps S2204 to S2209 in FIG. The historical motion vector predictor candidate derivation processing procedure is ended. If the current number of motion vector predictor candidates numCurrMvpCand is less than 2, which is the maximum number of elements in the motion vector predictor candidate list mvpListLX (step S2203 in FIG. 29: YES), the processing from step S2204 in FIG. 29 onward is performed.

Subsequently, steps S2205 to S2207 are performed for Y=0 and 1 (L0 and L1) respectively (steps S2204 to S2208 in FIG. 29). If the number of current motion vector predictor candidates numCurrMvpCand is equal to or greater than 2, which is the maximum number of elements in the motion vector predictor candidate list mvpListLX (step S2205 in FIG. 29: NO), the processing from steps S2206 to S2209 in FIG. The historical motion vector predictor candidate derivation processing procedure is ended. If the number of current motion vector predictor candidates numCurrMvpCand is less than 2, which is the maximum number of elements in the motion vector predictor candidate list mvpListLX (step S2205 in FIG. 29: YES), the processing from step S2206 onward in FIG. 29 is performed.

Subsequently, when the reference index of LY in the historical motion vector predictor candidate list HmvpCandList[NumHmvpCand-i] is the same as the reference index refIdxLX of the motion vector to be encoded/decoded (step S2206 in FIG. 29: YES), the motion vector predictor candidate As the last element of the list, mvpListLX[numCurrMvpCand], the numCurrMvpCand-th element of the motion vector predictor candidate list counting from 0, is filled with the (NumHmvpCand-i)-th element of the history motion vector predictor candidate list, HmvpCandList[[NumHmvpCand - i] is added (step S2207 in FIG. 29), and the current number of motion vector predictor candidates numCurrMvpCand is incremented by one. If the reference index of LY in the history motion vector predictor candidate list HmvpCandList[NumHmvpCand-i] is not the same as the reference index refIdxLX of the motion vector to be encoded/decoded (step S2206 in FIG. 29: NO), the additional processing in step S2207 is performed. skip.

The processes from steps S2205 to S2207 in FIG. 29 are performed for both L0 and L1 (steps S2204 to S2208 in FIG. 29).

The index i is incremented by 1, and if the index i is equal to or smaller than 4 or the number of historical motion vector predictor candidates NumHmvpCand, whichever is smaller, the processing from step S2203 onward is performed again (steps S2202 to S2209 in FIG. 29).

<History Merge Candidate Derivation Processing>
Next, the process of step S403 in FIG. 21, which is the process common to the history merge candidate derivation unit 345 of the normal merge mode derivation unit 302 on the encoding side and the history merge candidate derivation unit 445 of the normal merge mode derivation unit 402 on the decoding side. A method for deriving history merge candidates from the history merge candidate list HmvpCandList, which is a procedure, will be described in detail. FIG. 30 is a flowchart for explaining the history merging candidate derivation processing procedure.

First, initialization processing is performed (step S2301 in FIG. 30). Sets each element from 0 to (numCurrMergeCand -1) of isPruned[i] to the value FALSE, and sets the variable numOrigMergeCand to the number of elements registered in the current merge candidate list, numCurrMergeCand.

Subsequently, the initial value of the index hMvpIdx is set to 1, and the additional processing from steps S2303 to S2310 in FIG. 30 is repeated from this initial value to NumHmvpCand (steps S2302 to S2311 in FIG. 30). If the number of elements registered in the current merge candidate list, numCurrMergeCand, is not less than (the maximum number of merge candidates, MaxNumMergeCand-1), merge candidates have been added to all the elements in the merge candidate list, so this history merge candidate derivation The process ends (step S2303 in FIG. 30: NO). If the number numCurrMergeCand of elements registered in the current merge candidate list is equal to or less than (the maximum number of merge candidates MaxNumMergeCand-1) (step S2303 in FIG. 30: YES), the processing from step S2304 is performed.

First, sameMotion is set to FALSE (step S2304 in FIG. 30). Subsequently, the initial value of index i is set to 0, and steps S2306 and S2307 in FIG. 30 are performed from this initial value to 1 (S2305 to S2308 in FIG. 30).

Next, whether the (NumHmvpCand-hMvpIdx)-th element HmvpCandList[NumHmvpCand-hMvpIdx] of the history motion vector prediction candidate list and the i-th element mergeCandList[i] of the merge candidate list are the same value. It compares whether or not (step S2306 in FIG. 30). Here, the same value of the merge candidates means that the values of all components (inter prediction mode, reference index, motion vector) of the merge candidates are the same. However, this processing of step S2306 is limited to when hMvpIdx is greater than NumHmvpCand-2, mergeCandList[i] is a spatial merge candidate, and isPruned[i] is FALSE (false). If the values are the same (step S2306 in FIG. 30: YES), both sameMotion and isPruned[i] are set to TRUE (step S2307 in FIG. 30). If the values are not the same (step S2306 in FIG. 30: NO), the process of step S2307 is skipped. When the repeated processing from step S2305 to step S2308 in FIG. 30 is completed, it is compared whether sameMotion is FALSE (step S2309 in FIG. 30), and if sameMotion is FALSE (step S2309 in FIG. 30: YES), add the (NumHmvpCand - hMvpIdx)-th element HmvpCandList[NumHmvpCand - hMvpIdx] of the history motion vector predictor candidate list counting from 0 to the numCurrMergeCand-th mergeCandList[numCurrMergeCand] of the merge candidate list, and increment numCurrMergeCand by 1 ( step S2310 in FIG. 30). The index hMvpIdx is incremented by 1 (step S2302 in FIG. 30), and steps S2302 to S2311 in FIG. 30 are repeated.

When all elements of the history motion vector predictor candidate list have been confirmed or merge candidates have been added to all elements of the merge candidate list, this history merge candidate derivation process is completed.

<Average merge candidate derivation process>
Next, the process of step S404 in FIG. 21, which is common to the average merge candidate derivation unit 344 of the normal merge mode derivation unit 302 on the encoding side and the average merge candidate derivation unit 444 of the normal merge mode derivation unit 402 on the decoding side. The procedure for deriving average merge candidates will be described in detail. FIG. 38 is a flowchart for explaining the average merging candidate derivation processing procedure.

First, initialization processing is performed (step S1301 in FIG. 38). Set the number of elements registered in the current merge candidate list, numCurrMergeCand, to the variable numOrigMergeCand.

Subsequently, the merge candidate list is sequentially scanned from the top to determine two pieces of motion information. Let index i=0 indicating the first motion information and index j=1 indicating the second motion information. (Steps S1302 and S1303 in FIG. 38). If the number of elements registered in the current merge candidate list, numCurrMergeCand, is not less than (the maximum number of merge candidates, MaxNumMergeCand-1), merge candidates have been added to all the elements in the merge candidate list, so this history merge candidate derivation The process ends (step S1304 in FIG. 38). If the number of elements registered in the current merge candidate list, numCurrMergeCand, is less than (the maximum number of merge candidates, MaxNumMergeCand-1), the process from step S1305 is performed.

It is determined whether the i-th motion information mergeCandList[i] in the merge candidate list and the j-th motion information mergeCandList[j] in the merge candidate list are both invalid (step S1305 in FIG. 38), and both are invalid. If so, do not derive the average merge candidate for mergeCandList[i] and mergeCandList[j] and move on to the next element. If both mergeCandList[i] and mergeCandList[j] are not invalid, the following processing is repeated with X set to 0 and 1 (steps S1306 to S1314 in FIG. 38).

It is determined whether the LX prediction of mergeCandList[i] is valid (step S1307 in FIG. 38). If the LX prediction for mergeCandList[i] is valid, it is determined whether the LX prediction for mergeCandList[j] is valid (step S1308 in FIG. 38). If the LX prediction for mergeCandList[j] is valid, i.e. if both the LX prediction for mergeCandList[i] and the LX prediction for mergeCandList[j] are valid, then the motion vector for the LX prediction for mergeCandList[i] and mergeCandList Derive the average merge candidate for the LX prediction with the motion vector for the LX prediction that averaged the motion vector for the LX prediction in [j] and the reference index for the LX prediction in mergeCandList[i] and set it to the LX prediction for averageCand, LX prediction is validated (step S1309 in FIG. 38). In step S1308 of FIG. 38, if the LX prediction of mergeCandList[j] is not valid, that is, if the LX prediction of mergeCandList[i] is valid and the LX prediction of mergeCandList[j] is invalid, mergeCandList[i] LX prediction average merge candidate having a motion vector of LX prediction and reference index is derived, set to LX prediction of averageCand, and LX prediction of averageCand is validated (step S1310 in FIG. 38). If the LX prediction of mergeCandList[i] is not valid in step S1307 of FIG. 38, it is determined whether or not the LX prediction of mergeCandList[j] is valid (step S1311 of FIG. 38). If the LX prediction of mergeCandList[j] is valid, i.e. the LX prediction of mergeCandList[i] is invalid and the LX prediction of mergeCandList[j] is valid, then the motion vector of the LX prediction of mergeCandList[j] and The average merging candidate for the LX prediction with reference index is derived and set to the LX prediction of averageCand, and the LX prediction of averageCand is validated (step S1312 in FIG. 38). In step S1311 of FIG. 38, if the LX prediction for mergeCandList[j] is invalid, that is, if both the LX prediction for mergeCandList[i] and mergeCandList[j] are invalid, the LX prediction for averageCand is invalidated. (step S1312 in FIG. 38).

The average merge candidate averageCand of the L0 prediction, L1 prediction or BI prediction generated as described above is added to the numCurrMergeCand-th mergeCandList[numCurrMergeCand] of the merge candidate list, and numCurrMergeCand is incremented by 1 (step S1315 in FIG. 38). This completes the average merging candidate derivation process.

Note that the average merge candidate is averaged for each of the horizontal component of the motion vector and the vertical component of the motion vector.

<Motion Compensation Prediction Processing>
The motion compensation prediction unit 306 acquires the position and size of the block currently being subjected to prediction processing in encoding. Also, the motion compensation prediction unit 306 acquires inter prediction information from the inter prediction mode determination unit 305 . A reference index and a motion vector are derived from the acquired inter prediction information, and the reference picture specified by the reference index in the decoded image memory is moved from the same position as the image signal of the prediction block by the amount of the motion vector. Generate a predicted signal after acquiring the signal.

When the inter prediction mode in inter prediction is prediction from a single reference picture such as L0 prediction or L1 prediction, the prediction signal obtained from one reference picture is the motion compensation prediction signal, and the inter prediction mode is BI When the prediction mode is prediction from two reference pictures, such as prediction, the weighted average of the prediction signals obtained from the two reference pictures is used as the motion-compensated prediction signal, and the motion-compensated prediction signal is used to determine the prediction method. Department. Here, the weighted average ratio of bi-prediction is set to 1:1, but weighted average may be performed using other ratios. For example, the closer the picture interval between the picture to be predicted and the reference picture is, the higher the weighting ratio may be. Alternatively, the weighting ratio may be calculated using a correspondence table of combinations of picture intervals and weighting ratios.

The motion compensation prediction unit 406 has the same function as the motion compensation prediction unit 306 on the encoding side. The motion compensation prediction unit 406 passes the inter prediction information from the normal prediction motion vector mode derivation unit 401, the normal merge mode derivation unit 402, the sub-block prediction motion vector mode derivation unit 403, and the sub-block merge mode derivation unit 404 to switch 408. to get through.

The motion compensation prediction unit 406 supplies the obtained motion compensation prediction signal to the decoded image signal superimposing unit 207 .

<About inter-prediction mode>
The process of performing prediction from a single reference picture is defined as uniprediction, and in the case of uniprediction, either one of the two reference pictures registered in the reference lists L0 and L1, called L0 prediction or L1 prediction, is used. make predictions. L0 prediction and L1 prediction may be forward prediction (prediction referring to a forward reference image) or backward prediction (prediction referring to a backward reference image). 33 and 34 are diagrams for explaining motion compensation prediction in L0 prediction (uni-prediction).

FIG. 33 shows a case where the inter prediction mode is L0 prediction and the L0 reference picture (RefL0Pic) is at a time before the processing target picture (CurPic). FIG. 33 shows a case in which L0 prediction is performed and the reference picture of L0 is at a time later than the picture to be processed. Similarly, uni-prediction can be performed by replacing the L0 prediction reference picture in FIGS. 33 and 34 with the L1 prediction reference picture (RefL1Pic).

A process of performing prediction from two reference pictures is defined as bi-prediction, and bi-prediction is expressed as bi-prediction using both L0 prediction and L1 prediction. 35 to 37 are diagrams for explaining motion compensation prediction in bi-prediction. FIG. 35 shows a bi-prediction case where the reference picture for L0 prediction is before the picture to be processed and the reference picture for L1 prediction is after the picture to be processed. FIG. 36 shows a bi-prediction case in which the reference picture for L0 prediction and the reference picture for L1 prediction are located before the picture to be processed. FIG. 37 shows a bi-prediction case where the reference picture for L0 prediction and the reference picture for L1 prediction are located after the picture to be processed.

In this way, the relationship between the prediction type and time of L0/L1 is limited to forward prediction (prediction referring to a forward reference image) for L0 and backward prediction (prediction referring to a backward reference image) for L1. It is possible to use it without In the case of bi-prediction, L0 prediction and L1 prediction may be performed using the same reference picture. It should be noted that the determination of whether motion compensation prediction is performed by uni-prediction or bi-prediction is made based on information (for example, a flag) indicating whether to use L0 prediction and whether to use L1 prediction, for example. be.

<About reference index>
In the embodiments of the present invention, it is possible to select an optimum reference picture from among a plurality of reference pictures in motion compensation prediction in order to improve the accuracy of motion compensation prediction. Therefore, the reference picture used in motion compensated prediction is used as a reference index, and the reference index is coded into the coded stream together with the coded vector.

<Motion Compensation Processing Based on Normal Predicted Motion Vector Mode>
Motion compensation prediction section 306, as also shown in inter prediction section 102 on the encoding side in FIG. obtains this inter prediction information from the inter prediction mode determination unit 305, derives the inter prediction mode, reference index, and motion vector of the block currently being processed, and generates a motion compensated prediction signal. The generated motion-compensated prediction signal is supplied to the prediction method determination unit 105 .

Similarly, motion compensation prediction section 406, as shown in inter prediction section 203 on the decoding side in FIG. Inter prediction information is obtained by the predicted motion vector mode derivation unit 401, and the inter prediction mode, reference index, and motion vector of the block currently being processed are derived, and a motion compensated prediction signal is generated. The generated motion-compensated prediction signal is supplied to the decoded image signal superimposing unit 207 .

<Motion Compensation Processing Based on Normal Merge Mode>
As shown in the inter prediction unit 102 on the encoding side in FIG. This inter-prediction information is acquired from the inter-prediction mode determination unit 305, the inter-prediction mode, reference index, and motion vector of the block currently being processed are derived, and a motion compensated prediction signal is generated. The generated motion-compensated prediction signal is supplied to the prediction method determination unit 105 .

Similarly, as shown in the inter prediction unit 203 on the decoding side in FIG. Inter prediction information is obtained by the derivation unit 402, the inter prediction mode, reference index, and motion vector of the block currently being processed are derived, and a motion compensated prediction signal is generated. The generated motion-compensated prediction signal is supplied to the decoded image signal superimposing unit 207 .

<Merge Differential Motion Vector (MMVD)>
A differential motion vector can be added to the motion vectors of the top two merge candidates (merge candidates with merge indices of 0 and 1 in the merge candidate list). This differential motion vector is called a merge differential motion vector.

When the merge difference motion vector is added in the encoding-side merge candidate selection unit 347 , the motion vector to which the merge difference motion vector is added is supplied to the motion compensation prediction unit 306 via the inter prediction mode determination unit 305 . Also, the bitstream encoding unit 108 encodes information about the merge difference motion vector. The information about the merge difference motion vector is the index mmvd_distance_idx indicating the distance to be added to the motion vector and the index mmvd_direction_idx indicating the direction to add the motion vector. These indices are defined as in the tables shown in FIGS. 39(a) and 39(b). Then, if the x and y components of the merge differential motion vector offset MmvdOffset are represented by MmvdOffset[0] and MmvdOffset[1] respectively,
MmvdOffset[0] = ( MmvdDistance << 2 ) * MmvdSign[0]
MmvdOffset[1] = ( MmvdDistance << 2 ) * MmvdSign[1]
becomes. The merge differential motion vector is derived from the merge differential motion vector offset MmvdOffset in the above equation. The details of deriving the merge difference motion vector are described below in the case of the decoding side.

On the decoding side, if a merge differential motion vector exists, information about the merge differential motion vector is separated from the bitstream supplied to the bitstream decoding unit 201, and a merge differential motion vector offset MmvdOffset is derived. Also, the merge candidate selection unit 447 derives a merge differential motion vector from the decoded merge differential motion vector offset. After adding this merged differential motion vector to the motion vector, the motion vector is supplied to the motion compensated prediction unit 406 .

Derivation of the merge differential motion vector mMvdLX in the merge candidate selection unit 447 will be described with reference to the flowchart of FIG. First, it is determined whether or not the inter prediction mode of the coding block is bi-prediction (PRED_BI) (S4402). If it is not bi-prediction (S4402: No), it is determined whether it is L0 prediction (PRED_L0) (S4404). In the case of L0 prediction (S4404: Yes),
mMvdL0 = MmvdOffset
mMvdL1 = 0
(S4406), the process of deriving the merge difference motion vector ends. For L1 prediction (S4404: No),
mMvdL0 = 0
mMvdL1 = MmvdOffset
(S4408), the process of deriving the merge difference motion vector ends.

On the other hand, in the case of bi-prediction (S4402: Yes), the difference between the POC of the picture to be processed currPic and the reference picture is calculated for each reference list and set to currPocDiffL0 and currPocDiffL1 (S4410). Here, the POC difference between picA and picB, DiffPicOrderCnt(picA, picB), is
DiffPicOrderCnt( picA, picB ) = [POC of picA] - [POC of picB]
indicates Reference picture RefPicList0[refIdxL0] is a picture indicated by reference index refIdxL0 of reference list L0. Similarly, reference picture RefPicList1[refIdxL1] is a picture indicated by reference index refIdxL1 in reference list L1.

Next, it is determined whether -currPocDiffL0*currPocDiffL1>=0 (step S4412). If this determination is true (step S4412: Yes),
mMvdL0 = MmvdOffset
mMvdL1 = -MmvdOffset
As (step S4414), the process of deriving the merge difference motion vector ends. On the other hand, if this determination is false (step S4412: No),
mMvdL0 = MmvdOffset
mMvdL1 = MmvdOffset
(step S4416). Next, it is determined whether or not the absolute value of the POC difference from the reference list L0 is greater than or equal to the absolute value of the POC difference from the reference list L1 (step S4418). If this determination is true (step S4418: Yes), set X=0, Y=1 (step S4420), and scale the merged differential motion vector mMvdL1 of L1 (step S4424). Here, mMvdLY indicates mMvdL0 when Y=0 and mMvdL1 when Y=1. On the other hand, if this determination is false (step S4418: No), set X=1, Y=0 (step S4422), and scale the merged differential motion vector mMvdL0 of L0 (step S4424). The scaling of the merged differential motion vector mMvdLY is
td = Clip3( -128, 127, currPocDiffLX )
tb = Clip3( -128, 127, currPocDiffLY )
tx = ( 16384 + Abs( td ) >> 1 ) / td
distScaleFactor = Clip3( -4096, 4095, ( tb * tx + 32 ) >> 6 )
mMvdLY = Clip3( -131072, 131071, Sign( distScaleFactor * mMvdLY )
* ( (Abs( distScaleFactor * mMvdLY ) + 127 ) >> 8 ) )
derived as Here, currPocDiffLX indicates currPocDiffL0 when X=0 and currPocDiffL1 when X=1. Similarly, currPocDiffLY indicates currPocDiffL0 if Y=0 and currPocDiffL1 if Y=1. Clip3(x,y,z) is a function that limits the minimum value to x and the maximum value to y for the value z. Sign(x) is a function that returns the sign of the value x, which is 1 if the value x is positive, 0 if the value x is 0, and -1 if the value x is negative. Abs(x) is a function that returns the absolute value of the value x. >> is a bitwise operator indicating that the operand on the left side is bit-shifted to the right by the number of bits of the operand on the right side. With the above, the process of deriving the merge difference motion vector ends.

The merge difference motion vector may be added to the motion vectors of the top two sub-block merge candidates. In this case, the index mmvd_distance_idx indicating the distance to be added to the motion vector is defined as in the table shown in FIG. 39(c). Since the operation of the sub-block merge candidate selection unit 386 is the same as that of the merge candidate selection unit 347, description thereof will be omitted. Also, the operation of the sub-block merge candidate selection unit 486 is the same as that of the merge candidate selection unit 447, so the description is omitted.

As described above, MmvdDistance is defined as in the tables shown in FIGS. 39(a) and 39(c). Since these tables are defined with quarter-pixel precision, the generated merge difference motion vectors may contain fractional-pixel precision. However, by encoding/decoding the flag indicating that the pixel precision in these tables is 1 in units of slices, the generated merge difference motion vector can be changed so that it does not include fractional pixel precision. .

<Adaptive motion vector resolution (AMVR)>
The resolution of the differential motion vector can be adaptively changed for each encoding block. This resolution is called adaptive motion vector resolution.

A case of using the adaptive motion vector resolution for the normal motion vector predictor mode will be described. In this case, the spatial motion vector predictor candidate deriving units 321 and 421, the temporal motion vector predictor candidate deriving units 322 and 422, and the historical motion vector predictor candidate deriving units 323 and 423 derive the candidate motion vectors according to the resolution. is rounded. The resolution can be selected from 1/4, 1, and 4 pixel precision, and if the resolution is not changed, it will be 1/4 pixel precision. The rounding process is performed according to the motion vector resolution in the encoding block to be processed. That is, the derived candidate motion vector mvX is
rightShift = leftShift = MvShift + 2
offset = ( 1 << ( rightShift - 1 ) )
mvX = ( ( mvX + offset - ( mvX >= 0 ) ) >> rightShift ) << leftShift
and rounded. However, if rightShift=0, offset=0. Here, MvShift=0 when the resolution of the motion vector in the encoding block to be processed is 1/4 pixel precision. Similarly, MvShift=2 if the motion vector resolution is 1-pixel precision, and MvShift=4 if the motion vector resolution is 4-pixel precision. The above formula handles each of the x,y components of mvX.

Adaptive motion vector resolution can also be used for sub-block predictive motion vector mode. In this case, the resolution is different from the normal motion vector predictor mode described above. That is, in the affine inherited motion vector predictor candidate deriving units 361 and 461, the affine constructed motion vector predictor candidate deriving units 362 and 462, and the affine identical motion vector predictor candidate deriving units 363 and 463, the derived candidate motion vectors are rounded according to . The resolution can be selected from 1/16, 1/4, and 1 pixel precision, and if the resolution is not changed, it will be 1/4 pixel precision. The rounding process is performed according to the motion vector resolution in the encoding block to be processed. That is, the derived candidate motion vector mvX is rounded according to the above formula. Here, MvShift=0 when the resolution of the motion vector in the encoding block to be processed is 1/4 pixel precision. Similarly, MvShift=-2 if the motion vector resolution is 1/16 pixel precision, and MvShift=2 if the motion vector resolution is 1 pixel precision. The above equations process each of the x,y components of mvX.

<Intra block copy (IBC)>
A valid reference area for intra block copy will be described with reference to FIG. FIG. 32(a) is an example of determining a valid reference area using a coding tree block unit as an intra block copy reference block. 500, 501, 502, 503, and 504 in FIG. 32(a) are coding tree blocks, and 504 is a coding tree block to be processed. 505 is an encoding block to be processed. The processing order of the coding tree blocks is 500, 501, 502, 503, 504. In this case, the three coding tree blocks 501, 502, and 503 processed immediately before the coding tree block 504 including the coding block 505 to be processed are set as the effective reference regions of the coding block 505 to be processed. Coding treeblocks processed before coding treeblock 501, and coding treeblocks including target codingblock 505, regardless of whether processing was completed prior to target codingblock 505. All areas included in 504 are invalid reference areas.

FIG. 32(b) is an example of determining an effective reference area by using a unit obtained by dividing a coding tree block into four units as an intra block copy reference block. 515 and 516 in FIG. 32(b) are coding tree blocks, and 516 is a coding tree block to be processed. Coding tree block 515 is quadranted into 506, 507, 508 and 509, and 516 is quadrant into 510, 511, 512 and 513. 514 is an encoding block to be processed. The processing order of intra block copy reference blocks is 506, 507, 508, 509, 510, 511, 512, and 513. FIG. In this case, the three intra block copy reference blocks 508 , 509 , and 510 processed immediately before the intra block copy reference block 511 including the target encoding block 514 are used as valid reference regions for the target encoding block 514 . Coding tree blocks processed before intra block copy reference block 508 and intra block copy including current coding block 514 regardless of whether processing was completed before current coding block 514 All areas included in the reference block 511 are invalid reference areas.

<Predicted Intra Block Copy: Explanation on Encoding Side>
A predictive intra block copy processing procedure on the encoding side will be described with reference to FIG.

First, block vector mvL is detected by block vector detector 375 (step S4500 in FIG. 45).

Subsequently, an IBC spatial block vector candidate derivation unit 371, an IBC history prediction block vector candidate derivation unit 372, an IBC prediction block vector candidate supplementation unit 373, an IBC prediction block vector candidate selection unit 376, and a block vector subtraction unit 378 perform prediction block vector A difference block vector of the block vectors used in the mode is calculated (steps S4501 to S4503 in FIG. 45).

Prediction block vector candidates are calculated to construct a block vector candidate list mvpList (step S4501 in FIG. 45). An IBC spatial block vector candidate derivation unit 371, an IBC history block vector candidate derivation unit 372, and an IBC prediction block vector candidate supplementation unit 373 in the intra block copy prediction unit 352 derive a plurality of prediction block vector candidates to obtain a prediction block vector. Construct the candidate list mvpList. A detailed processing procedure of step S4501 in FIG. 45 will be described later using the flowchart in FIG.

Subsequently, the IBC predictive block vector candidate selection unit 376 selects the predictive block vector mvpL from the predictive block vector candidate list mvpListL (step S4502 in FIG. 45). Differential block vectors, which are the differences between the block vector mvL and each predictive block vector candidate mvpListL[i] stored in the predictive block vector candidate list mvpListL, are calculated. A code amount when the difference block vectors are encoded is calculated for each element of the predictive block vector candidate list mvpListL. Then, among the elements registered in the predictive block vector candidate list mvpListL, the predictive block vector candidate mvpListL[i] having the smallest code amount for each predictive block vector candidate is selected as the predictive block vector mvpL. Get index i. If there are multiple predictive block vector candidates with the smallest generated code amount in the block vector predictor candidate list mvpListL, the predictive block vector whose index i in the block vector predictor candidate list mvpListL is represented by a small number. is selected as the optimal predictive block vector mvpL, and its index i is obtained.

Subsequently, the block vector subtraction unit 378 subtracts the selected predicted block vector mvpL from the block vector mvL,
mvdL = mvL - mvpL
, the difference block vector mvdL is calculated (step S4503 in FIG. 45).

<Intra block copy (prediction): Description on the decoding side>
Next, the predictive block vector mode processing procedure on the decoding side will be described with reference to FIG. On the decoding side, an IBC spatial prediction block vector candidate derivation unit 471, an IBC history block vector candidate derivation unit 472, and an IBC prediction block vector supplementation unit 473 calculate block vectors used in the prediction block vector mode (steps S4600 to S4600 in FIG. 46). S4602). Specifically, a predictive block vector candidate list mvpListL is calculated, a predictive block vector mvpL is selected, and a block vector mvL is calculated.

Predictive block vector candidates are calculated to construct a predictive block vector candidate list mvpListL (step S4601 in FIG. 46). An IBC spatial block vector candidate deriving unit 471, an IBC history block vector candidate deriving unit 472, and an IBC block vector supplementing unit 473 in the intra block copy prediction unit 362 calculate a plurality of predictive block vector candidates, and create a predictive block vector candidate list. Build mvpListL. Description of the detailed processing procedure of step S4601 in FIG. 46 is omitted.

Subsequently, the IBC predictive block vector candidate selection unit 476 selects a predictive block vector candidate mvpListL[mvpIdxL] corresponding to the predictive block vector index mvpIdxL decoded and supplied by the bit string decoding unit 201 from the predictive block vector candidate list mvpListL. It is taken out as the selected predictive block vector mvpL (step S4601 in FIG. 46).

Subsequently, the block vector addition unit 478 adds the differential block vector mvdL and the predicted block vector mvpL decoded and supplied by the bit string decoding unit 201,
mvL = mvpL + mvdL
to calculate the block vector mvL (step S4602 in FIG. 46).

<Prediction Block Vector Mode: Block Vector Prediction Method>
FIG. 48 shows prediction intra block copy mode derivation processing having functions common to the intra block copy prediction unit 352 of the video encoding device and the intra block copy prediction unit 362 of the video decoding device according to the embodiment of the present invention. It is a flow chart showing a processing procedure.

The intra block copy prediction unit 352 and the intra block copy prediction unit 362 are provided with a prediction block vector candidate list mvpListL. The block vector predictor candidate list mvpListL has a list structure, and is provided with a block vector predictor index indicating the location inside the block vector predictor candidate list and a storage area for storing the block vector predictor candidate corresponding to the index as an element. The prediction block vector index number starts from 0, and the prediction block vector candidates are stored in the storage area of the prediction block vector candidate list mvpListL. In this embodiment, it is assumed that the predictive block vector candidate list mvpListL can register three predictive block vector candidates. Furthermore, 0 is set to a variable numCurrMvpIbcCand indicating the number of predictive block vector candidates registered in the predictive block vector candidate list mvpListL.

Subsequently, the IBC history block vector candidate deriving units 372 and 472 add the history block vector candidates registered in the history block vector candidate list HmvpIbcCandList to the predictive block vector candidate list mvpListL. (Step S304 in FIG. 20). Details of the registration processing procedure in step S304 will be described later using the flowchart of FIG.

Subsequently, the IBC predictive block vector supplementing units 373 and 473 add block vectors of predetermined values such as (0, 0) until the predictive block vector candidate list mvpListL is satisfied (S305 in FIG. 20).

<Merging intra-block copy mode derivation unit>
The intra block copy prediction unit 352 in FIG. 43 includes an IBC spatial block vector candidate derivation unit 371, an IBC history block vector candidate derivation unit 372, an IBC block vector supplementation unit 373, a reference position correction unit 380, an IBC merge candidate selection unit 374, an IBC A prediction mode determination unit 377 is included.

44 includes an IBC spatial block vector candidate derivation unit 471, an IBC history block vector candidate derivation unit 472, an IBC block vector supplementation unit 473, an IBC merge candidate selection unit 474, a reference position correction unit 480, a block A copy unit 477 is included.

FIG. 47 shows a merge intra block copy mode derivation process having functions common to the intra block copy prediction unit 352 of the video encoding device and the intra block copy prediction unit 362 of the video decoding device according to the embodiment of the present invention. It is a flow chart explaining a procedure.

The intra block copy prediction unit 352 and the intra block copy prediction unit 362 have a merge intra block copy candidate list mergeIbcCandList. The merge intra block copy candidate list mergeIbcCandList has a list structure, and is provided with a merge index indicating the location inside the merge intra block copy candidate and a storage area for storing the merge intra block copy candidate corresponding to the index as an element. The number of the merge index starts from 0, and the merge intra block copy candidates are stored in the storage area of the merge intra block copy candidate list mergeIbcCandList. In the subsequent processing, merge candidates with merge index i registered in the merge intra block copy candidate list mergeIbcCandList are represented by mergeIbcCandList[i]. In this embodiment, the merge candidate list mergeCandList can register at least three merge intra block copy candidates. Furthermore, 0 is set to a variable numCurrMergeIbcCand indicating the number of merge intra block copy candidates registered in the merge intra block copy candidate list mergeIbcCandList.

In the IBC spatial block vector candidate derivation unit 371 and the IBC spatial block vector candidate derivation unit 471, the encoding stored in the encoding information storage memory 111 of the video encoding device or the encoding information storage memory 205 of the video decoding device. Spatial merge candidates A and B are derived from the blocks adjacent to the left and upper sides of the block to be processed from the information, and the derived spatial merge candidates are registered in the merge intra block copy candidate list mergeIbcCandList (step S4701 in FIG. 47). ). Here, N is defined to indicate either spatial merge candidate A or B. A flag availableFlagN and a block vector mvL indicating whether intra block copy prediction information of block N can be used as a spatial block vector merging candidate N are derived. However, in the present embodiment, block vector merging candidates are derived without referring to other encoding blocks included in the block including the encoding block to be processed. does not derive spatial block vector merge candidates contained in .

Subsequently, the IBC history block vector candidate derivation unit 372 and the IBC history block vector candidate derivation unit 472 add the history prediction block vector candidates registered in the history prediction block vector candidate list HmvpIbcCandList to the intra block merge candidate list mergeIbcCandList ( Step S4702 in FIG. 47). In this embodiment, if the block vector already added to mergeIbcCandList and the block vector of the historical prediction block vector candidate have the same value, addition to mergeIbcCandList is not performed.

Subsequently, when the number of merge candidates numCurrMergeIbcCand registered in the merge intra block copy candidate list mergeIbcCandList is smaller than the maximum number of intra block merge candidates MaxNumMergeIbcCand, The number of merge candidates numCurrMergeIbcCand registered in the merge intra block copy candidate list mergeIbcCandList derives additional intra block merge candidates up to the maximum number of merge candidates MaxNumMergeIbcCand, and registers them in the merge intra block copy candidate list mergeIbcCandList (see FIG. 47). step S4703). With the maximum number of merge candidates MaxNumMergeIbcCand as the upper limit, block vectors having values of (0, 0) are added to the merge intra block copy candidate list mergeIbcCandList.

Subsequently, the IBC merge candidate selection unit 374 and the IBC merge candidate selection unit 474 select one intra block merge candidate registered in the merge intra block copy candidate list mergeIbcCandList (step S4704 in FIG. 47). The IBC merge candidate selection unit 374 acquires the decoded image at the reference position from the decoded image memory 104, calculates the code amount and distortion amount, selects a merge candidate, and sets a merge index indicating the selected intra block merge candidate. It is supplied to the IBC prediction mode determination unit 377 . The IBC prediction mode determination unit 377 selects whether or not it is the merge mode by calculating the code amount and the distortion amount, and supplies the result to the prediction method determination unit 105 . On the other hand, the decoding-side IBC merge candidate selection unit 474 selects an intra block merge candidate based on the decoded merge index, and supplies the selected intra block merge candidate to the reference position correction unit 480 .

Subsequently, the reference position correcting unit 380 and the reference position correcting unit 480 perform a process of correcting the reference positions of the intra block merge candidates (step S4705 in FIG. 47). Details of the processing of the reference position correction section 380 and the reference position correction section 480 will be described later.

The block copy unit 477 acquires the decoded image at the reference position from the decoded image memory 208 and supplies it to the decoded image signal superimposing unit 207 . Here, the block copy unit 477 copies the luminance component and the color difference component.

The above block vector mvL indicates a luminance block vector. The chrominance block vector mvC is derived from the corrected luma block vector, and if the chrominance format is 420,
mvC = ( ( mvL >> ( 3 + 2 ) ) * 32
becomes. The above formula handles each x,y component of mvC.

The corrected luminance block vector is stored in the encoding information storage memory 111 of the video encoding device or the encoding information storage memory 205 of the video decoding device.

<Reference position corrector>
FIG. 49 is a flowchart for explaining the processing of the reference position correction section 380 and the reference position correction section 480. FIG. Now, assume that the intra block copy reference block unit is a coding tree block (CTU) and its size is not 128×128 pixels.

First, the upper left and lower right positions of the reference block are calculated (S6001). A reference block refers to a block that is referred to by an encoding block to be processed using a block vector. If the upper left of the reference block is ( xRefTL, yRefTL ) and the lower right is ( xRefBR, yRefBR ),
( xRefTL, yRefTL ) = ( xCb + ( mvL[ 0 ] >> 4 ), yCb + ( mvL[ 1 ] >> 4 ) )
( xRefBR, yRefBR ) = ( xRefTL + cbWidth - 1, yRefTL + cbHeight - 1 )
becomes. Here, the position of the encoding block to be processed is (xCb, yCb), the block vector is (mvL[0], mvL[1]), the width of the encoding block to be processed is cbWidth, and the height is cbHeight.

Next, it is determined whether or not the size of the CTU is 128×128 pixels (S6002). Since the size is not 128×128 pixels (S6002: NO), the upper left and lower right positions of the referable area are calculated (S6003). Let the upper left of the referable area be ( xAvlTL, yAvlTL ) and the lower right be ( xAvlBR, yAvlBR ),
NL = Min( 1, 7 - CtbLog2SizeY ) - ( 1 << ((7 - CtbLog2SizeY) << 1) )
( xAvlTL, yAvlTL ) = ( ((xCb >> CtbLog2SizeY) + NL) << CtbLog2SizeY,
(yCb >> CtbLog2SizeY) << CtbLog2SizeY )
( xAvlBR, yAvlBR ) = ( ((xCb >> CtbLog2SizeY) << CtbLog2SizeY) - 1,
(((yCb >> CtbLog2SizeY) + 1) << CtbLog2SizeY) - 1 )
becomes. Here, the CTU size is CtbLog2SizeY.

Next, it is determined whether or not the reference block fits within the referable area (S6004). Specifically, the determination is made by comparing the upper left coordinates of the reference block and the upper left coordinates of the referable area, and by comparing the lower right coordinates of the reference block and the lower right coordinates of the referable area. That is, if the upper left x-direction reference position of the reference block is smaller than the upper left x-direction position of the referenceable area, then the upper left y-direction reference position of the reference block is smaller than the upper left y-direction position of the referenceable area. , and if the x-direction reference position of the lower right of the reference block is greater than the x-direction position of the lower right of the referable area, then the y-direction reference position of the lower right of the reference block is If either condition is satisfied, it is determined that the reference block does not fit in the referable area (S6005: NO).

On the other hand, if all the above conditions are satisfied (S6004: YES), the process proceeds to step S6005. Here, when the block vector indicates (0, 0), that is, when it indicates the same position as the target block to be processed, the upper left position and lower right position of the reference block, and the upper left position of the referable area , it is determined that the reference block does not fit in the referenceable area without obtaining the lower right position. Therefore, if the block vector indicates (0, 0), it can also be used to determine that the reference block does not fit in the referable area.

If it is determined in step S6004 that the reference block fits within the referable area, the reference position of the reference block is corrected. Now, let the position of the CTU to be processed be (xCtb, yCtb). At this time, regardless of the value of the reference position of the reference block,
(xRefTL, yRefTL ) = ( xCtb - (1 << CtbLog2SizeY), yCtb )
corrects the reference position of the reference block.

FIG. 50(a) is a diagram showing how the reference position is corrected. Reference numeral 6001 denotes a coding tree block to be processed, 6002 denotes a coding block to be processed, and 6003 denotes a referable region. Now, assuming that the reference block is located at the same position 6002 as the target encoding block, that is, outside the reference area, the corrected reference block r' (6004) is the CTU immediately before the target CTU. Upper left position. In correcting the reference position, the block vector mvL[0] may be corrected. i.e.
mvL[0] = - ((xCb - xCtb) + (1 << CtbLog2SizeY))
mvL[1] = - (yCb - yCtb)
and correct.

The present invention is not limited to a configuration in which the post-correction reference position is the upper left position of the CTU immediately preceding the CTU to be processed. FIG. 50(b) is an example in which the upper right position of the CTU immediately preceding the target CTU is set as the post-correction reference position. In FIG. 50(b), 6005 corresponds to the corrected reference block r'. At this time, the position of the reference block after correction is
(xRefTL, yRefTL) = (xCtb - cbWidth, yCtb)
determined by In correcting the reference position, the block vector mvL[0] may be corrected. i.e.
mvL[0] = - (xCb - xCtb)
mvL[1] = - (yCb - yCtb)
and correct.

FIG. 50(c) is an example in which the lower left position of the CTU immediately preceding the target CTU is set as the post-correction reference position. In FIG. 50(c), 6006 corresponds to the corrected reference block r'. At this time, the position of the reference block after correction is
(xRefTL, yRefTL ) = ( xCtb - (1 << CtbLog2SizeY), yCtb + (1 << CtbLog2SizeY) - cbHeight)
determined by In correcting the reference position, the block vector mvL[0] may be corrected. i.e.
mvL[0] = - ((xCb - xCtb) + (1 << CtbLog2SizeY))
mvL[1] = - (yCb - yCtb) + (1 << CtbLog2SizeY) - yCb
and correct.

FIG. 50(d) is an example in which the lower right position of the CTU immediately preceding the target CTU is set as the post-correction reference position. In FIG. 50(d), 6007 corresponds to the corrected reference block r'. At this time, the position of the reference block after correction is
(xRefTL, yRefTL ) = ( xCtb - cbWidth, yCtb + (1 << CtbLog2SizeY) - cbHeight )
determined by In correcting the reference position, the block vector mvL[0] may be corrected. i.e.
mvL[0] = - (xCb - xCtb)
mvL[1] = - (yCb - yCtb) + (1 << CtbLog2SizeY) - yCb
and correct.

All of (a) to (d) of FIG. 50 are common in that the reference position of the reference block is corrected regardless of the value of the reference position of the reference block before correction.

In addition, the present invention does not limit the reference position after correction to this. For example, as shown in FIG. can also 6008 in FIG. 51(a) is an example in which the center position of the CTU immediately before the target CTU is used as the corrected reference block. At this time, the position of the reference block after correction is
(xRefTL, yRefTL ) = ( xCtb -(1<<(CtbLog2SizeY-1) - cbWidth/2, yCtb + (1<<(CtbLog2SizeY-1)) - cbHeight/2)
determined by Similarly, as shown in FIG. 51(b), it is also possible to use a position not included in the immediately preceding CTU as the reference position of the corrected reference block. 6009 to 6012 in FIG. 51(b) are an example in which the CTU two before the target CTU is set as the reference position after correction.

Assume that some block vectors in the block vector candidate list constructed by the intra block copy prediction unit 352 are outside the referable area. If the reference position is not corrected, reference by those block vectors is impossible, so those block vectors cannot be candidates for the IBC merge mode. On the other hand, when correcting the reference position in the present invention, all block vectors in the constructed block vector candidate list are inside the referable area. Therefore, all block vectors can be referenced, and all block vectors can be candidates for the IBC merge mode. Therefore, the IBC merge mode selection unit 374 can select the optimum prediction mode from the IBC merge mode candidates corresponding to all block vectors, thereby improving the coding efficiency.

Assume that some block vectors in the block vector candidate list constructed by the intra block copy prediction unit 362 are outside the referable area. If the reference position is not corrected, reference by those block vectors is impossible, so decoding in IBC merge mode using those block vectors is impossible. In a non-inventive coding apparatus, the merge index indicating the IBC merge mode using those block vectors behaves as if they were not coded. However, due to malfunctions, etc., such a merge index may be encoded to generate a bitstream. Alternatively, part of the bitstream may be lost due to packet loss or the like, and the decoded result may become such a merge index. When trying to decode such an incomplete bitstream, there is a possibility of accessing the decoded image memory at an incorrect position by trying to refer to the outside of the referenceable area. As a result, the decoding result differs depending on the decoding device, or the decoding process stops. On the other hand, when correcting the reference position in the present invention, all block vectors in the constructed block vector candidate list are inside the referable area. Therefore, even if such an incomplete bitstream is decoded, the reference position is corrected inside the referenceable area, and the reference can be made. By correcting the reference position in this way, the memory access range is guaranteed. As a result, the decoding result becomes the same depending on the decoding device, and the decoding process can be continued, so that the robustness of the decoding device can be improved.

Further, when correcting a block vector in correcting a reference position, the target is a block vector of luminance. Here, the chrominance block vector is calculated from the luminance block vector. In other words, if the luminance block vector is corrected, the chrominance block vector is also corrected. Therefore, there is no need to correct the reference position again for the color difference. The amount of processing can be reduced compared to the need to determine whether or not the block vector can be referenced using both luminance and color difference when the block vector is not corrected.

In addition, when correcting the block vector in correcting the reference position, the corrected block vector is saved as the block vector of the encoding block to be processed. That is, the corrected reference position and the position indicated by the block vector are the same. Here, deblocking filter processing may be performed when saving the decoded result in the decoded image memory. In this filtering process, the strength of the filter is controlled by the difference between the block vectors of two blocks facing the block boundary. When the block vector is not corrected, the corrected reference position and the position indicated by the block vector are different. Compared to this, the strength of the filter is more appropriate, so that the coding efficiency can be improved.

Furthermore, in correcting the reference position, it is possible to uniquely determine the post-correction reference position without depending on the position of the reference block. Therefore, it is possible to reduce the amount of processing involved in correcting the reference position.

The above completes the processing when the size of the CTU is not 128×128 pixels. On the other hand, if the size of the CTU is 128×128 pixels (S6002: YES), the upper left and lower right positions of the referable areas A and B are calculated (S6012, S6013, S6014).

FIG. 52 is a diagram for explaining the upper left and lower right positions of the referable areas A and B. FIG. In the case of FIG. 51(a), the encoding tree block 6101 to be processed is divided into four, and the encoding block 6102 to be processed is located on the upper left of the division. At this time, the referable area A is a block 6106 obtained by synthesizing the blocks 6103 and 6105, and the referable area B is a block 6107 obtained by synthesizing the blocks 6104 and 6105. FIG. Let the upper left and lower right of the referable area A be (xAvlTLA, yAvlTLA) and (xAvlBRA, yAvlBRA), respectively. Let the upper left and lower right of the referable area B be (xAvlTLB, yAvlTLB) and (xAvlBRB, yAvlBRB), respectively. If the upper left of the reference block is ( xRefTL, yRefTL ) and the lower right is ( xRefBR, yRefBR ),
( xAvlTLA, yAvlTLA ) = (((xCb >> CtbLog2SizeY) << CtbLog2SizeY) - (1 << (CtbLog2SizeY-1)),
(yCb >> CtbLog2SizeY) << CtbLog2SizeY )
( xAvlBRA, yAvlBLA ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY - 1 ,
((yCb >> CtbLog2SizeY) + 1 ) << CtbLog2SizeY) - 1 )
( xAvlTLB, yAvlTLB ) = ( ((xCb >> CtbLog2SizeY) - 1) << CtbLog2SizeY,
((yCb >> CtbLog2SizeY) << CtbLog2SizeY) + (1 << (CtbLog2SizeY-1)) )
( xAvlBRB, yAvlBLB ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY - 1,
((yCb >> CtbLog2SizeY) + 1 ) << CtbLog2SizeY) - 1 )
becomes. Similarly, in the case of FIG. 51(b),
( xAvlTLA, yAvlTLA ) = ( ((xCb >> CtbLog2SizeY) - 1) << CtbLog2SizeY,
((yCb >> CtbLog2SizeY) << CtbLog2SizeY) + (1 << (CtbLog2SizeY-1)) )
( xAvlBRA, yAvlBLA ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY - 1,
((yCb >> CtbLog2SizeY) + 1 ) << CtbLog2SizeY) - 1 )
( xAvlTLB, yAvlTLB ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY,
(yCb >> CtbLog2SizeY) << CtbLog2SizeY )
( xAvlBRB, yAvlBLB ) = ( ((xCb >> CtbLog2SizeY) << CtbLog2SizeY) + (1 << (CtbLog2SizeY-1)) - 1,
((yCb >> CtbLog2SizeY) + 1 ) << CtbLog2SizeY) - 1 )
becomes. Similarly, in the case of FIG. 51(c),
( xAvlTLA, yAvlTLA ) = ( ((xCb >> CtbLog2SizeY) << CtbLog2SizeY) - (1 << (CtbLog2SizeY-1)),
((yCb >> CtbLog2SizeY) << CtbLog2SizeY) + (1 << (CtbLog2SizeY-1)) )
( xAvlBRA, yAvlBLA ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY - 1,
((yCb >> CtbLog2SizeY) + 1 ) << CtbLog2SizeY) - 1 )
( xAvlTLB, yAvlTLB ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY,
(yCb >> CtbLog2SizeY) << CtbLog2SizeY )
( xAvlBRB, yAvlBLB ) = ( ((xCb >> CtbLog2SizeY) + 1 ) << CtbLog2SizeY) - 1,
((yCb >> CtbLog2SizeY) << CtbLog2SizeY) + (1 << (CtbLog2SizeY-1)) - 1)
becomes. Similarly, in the case of FIG. 51(d),
( xAvlTLA, yAvlTLA ) = ( (xCb >> CtbLog2SizeY) << CtbLog2SizeY,
(yCb >> CtbLog2SizeY) << CtbLog2SizeY )
becomes.

Next, it is determined whether or not the reference block fits within the referable area (S6004). Specifically, the coordinates of the upper left of the reference block and the upper left of the referenceable area A are compared, the coordinates of the lower right of the reference block A and the lower right of the referenceable area are compared, and the upper left of the reference block and the referenceable area B are compared. and the coordinates of the lower right of the reference block B and the lower right of the referable area. That is, for each of the referenceable areas A and B, if the upper left x-direction reference position of the reference block is smaller than the upper left x-direction position of the referenceable area A (B), the upper left of the reference block A (B) If the y-direction reference position is smaller than the upper left y-direction position of the referable area, and if the lower right x-direction reference position of reference block A (B) is lower than the lower right x-direction position of the reference block A (B) If it is larger, or if the y-direction reference position at the bottom right of the reference block is greater than the y-direction position at the bottom right of the referable area A (B), the reference block can be referenced It is determined that it does not fit in the area (S6005: NO).

On the other hand, if all the above conditions are satisfied (S6004: YES), the process proceeds to step S6005. Here, when the block vector indicates (0, 0), that is, when it indicates the same position as the target block to be processed, the upper left position and lower right position of the reference block, and the upper left position of the referable area , it is determined that the reference block does not fit in the referenceable area without obtaining the lower right position. Therefore, if the block vector indicates (0, 0), it can also be used to determine that the reference block does not fit in the referable area.

If it is determined in step S6004 that the reference block fits within the referable area, the reference position of the reference block is corrected. Now, let the position of the CTU to be processed be (xCtb, yCtb). At this time, regardless of the value of the reference position of the reference block,
(xRefTL, yRefTL ) = ( ((xCb >> (CtbLog2SizeY-1)) << (CtbLog2SizeY-1)) -(1 << (CtbLog2SizeY-1)), (yCb >> (CtbLog2SizeY-1)) << (CtbLog2SizeY-1)) )
corrects the reference position of the reference block.

FIG. 53(a) is a diagram showing how the reference position is corrected in the case of FIG. 52(a). Reference numeral 6101 denotes a coding tree block to be processed, 6102 denotes a coding block to be processed, and 6103, 6104, and 6105 referable regions. Now, assuming that the reference block is located at the same position 6102 as the encoding block to be processed, the corrected reference block r′ (6108) is located at the upper left position of the reference block 6103 . The present invention is not limited to the configuration in which the post-correction reference position is the position 6108 . Instead of 6108 in (a) of FIG. 53, 6109, which is the upper left position of the reference block 6104, or 6110, which is the upper left position of the reference block 6105, can be used as the corrected reference position. Furthermore, as in FIG. 51, it is also possible to adopt a configuration in which any one of reference blocks 6103, 6104, and 6105 is positioned at the center.

FIG. 53(b) is a diagram showing how the reference position is corrected in the case of FIG. 52(b). Now, assuming that the reference block is located at the same position 6102 as the encoding block to be processed, the corrected reference block r′ (6108) is located at the upper left position of the reference block 6103 . The present invention is not limited to the configuration in which the post-correction reference position is the position 6108 . Instead of 6108 in FIG. 53(b), 6109, which is the upper left position of the reference block 6104, or 6110, which is the upper left position of the reference block 6105, can be used as the corrected reference position. Furthermore, as in FIG. 51, it is also possible to adopt a configuration in which any one of reference blocks 6103, 6104, and 6105 is positioned at the center.

FIG. 53(c) is a diagram showing how the reference position is corrected in the case of FIG. 52(c). Now, assuming that the reference block is located at the same position 6102 as the encoding block to be processed, the corrected reference block r′ (6108) is located at the upper left position of the reference block 6103 . The present invention is not limited to the configuration in which the post-correction reference position is the position 6108 . Instead of 6108 in (c) of FIG. 53, 6109, which is the upper left position of the reference block 6104, or 6110, which is the upper left position of the reference block 6105, can be used as the corrected reference position. Furthermore, as in FIG. 51, it is also possible to adopt a configuration in which any one of reference blocks 6103, 6104, and 6105 is positioned at the center.

FIG. 53(d) is a diagram showing how the reference position is corrected in the case of FIG. 52(d). Now, assuming that the reference block is located at the same position 6102 as the encoding block to be processed, the corrected reference block r′ (6108) is located at the upper left position of the reference block 6103 . The present invention is not limited to the configuration in which the post-correction reference position is the position 6108 . Instead of 6108 in (d) of FIG. 53, 6109, which is the upper left position of the reference block 6104, or 6110, which is the upper left position of the reference block 6105, can be used as the corrected reference position. Furthermore, as in FIG. 51, it is also possible to adopt a configuration in which any one of reference blocks 6103, 6104, and 6105 is positioned at the center.

All of (a) to (d) of FIG. 53 are common in that the reference position of the reference block is corrected regardless of the value of the reference position of the reference block before correction.

Therefore, according to the configuration of the present invention, even if the referable area is not rectangular, the post-correction reference position can be uniquely determined without depending on the position of the reference block. Position can be corrected.

As described above, when the size of the CTU is 128×128 pixels, even if the reference block is positioned outside the referable area, the reference position can be corrected and referenced. Further, by dividing the referable area into two and correcting the respective reference positions, the processing can be simplified and the amount of calculation can be reduced. Here, one referable area (6301) is referred to as a referable area A, and the other referable area (6302) is referred to as a referable area B. FIG. Alternatively, the referable area A and the referable area B may be exchanged, and one referable area (6301) may be treated as the referable area B and the other referable area (6302) may be treated as the referable area A. .

In this embodiment, it is determined whether or not the size of the CTU is 128×128 pixels (S6002), and the process is switched. This may be done by determining whether or not the intra block copy reference block is a unit obtained by dividing the coding tree block into four, or by determining whether or not the size of the CTU is larger than the maximum size of the coding block. You can make it work.

In all the embodiments described above, the encoded bitstream output by the image encoding device has a specific data format so that it can be decoded according to the encoding method used in the embodiments. are doing. The encoded bitstream may be provided by being recorded in a computer-readable recording medium such as an HDD, SSD, flash memory, or optical disk, or may be provided from a server through a wired or wireless network. Therefore, an image decoding device corresponding to this image encoding device can decode the encoded bitstream of this specific data format regardless of the providing means.

When a wired or wireless network is used to exchange an encoded bitstream between an image encoding device and an image decoding device, the encoded bitstream is converted into a data format suitable for the transmission mode of the communication channel. may be transmitted. In this case, a transmission device that converts an encoded bitstream output from an image encoding device into encoded data in a data format suitable for the transmission mode of a communication channel and transmits the encoded data to a network, and a transmission device that receives encoded data from the network. and a receiving device for restoring an encoded bitstream to supply to an image decoding device. The transmission device includes a memory that buffers the encoded bitstream output from the image encoding device, a packet processing unit that packetizes the encoded bitstream, and a transmission unit that transmits the packetized encoded data via the network. including. The receiving device includes a receiving unit that receives packetized encoded data via a network, a memory that buffers the received encoded data, and packetizes the encoded data to generate an encoded bitstream, and a packet processing unit provided to the image decoding device.

When a wired or wireless network is used to exchange coded bitstreams between an image coding device and an image decoding device, in addition to the transmitting device and the receiving device, the coded data transmitted by the transmitting device is also used. A relay device may be provided for receiving and supplying to the receiving device. The relay device includes a receiver that receives packetized encoded data transmitted by the transmitter, a memory that buffers the received encoded data, and a transmitter that transmits the packetized encoded data and the network. include. Further, the relay device includes a reception packet processing unit that performs packet processing on packetized encoded data to generate an encoded bitstream, a recording medium that stores the encoded bitstream, and a packetization of the encoded bitstream. A transmission packet processing unit may be included.

Further, the display device may be configured by adding a display unit for displaying an image decoded by the image decoding device. In this case, the display unit reads the decoded image signal generated by the decoded image signal superimposition unit 207 and stored in the decoded image memory 208 and displays it on the screen.

Further, an imaging device may be configured by adding an imaging unit to the configuration and inputting a captured image to an image encoding device. In that case, the imaging unit inputs the image signal of the imaged image to the block dividing unit 101 .

The above encoding and decoding processes may of course be implemented as transmission, storage, and reception devices using hardware, and are stored in ROM (read only memory), flash memory, or the like. It may be implemented by firmware or software such as a computer. The firmware program and software program may be recorded in a computer-readable recording medium and provided, may be provided from a server through a wired or wireless network, or may be provided from a terrestrial or satellite digital broadcasting data broadcast. may be provided as

The present invention has been described above based on the embodiments. It should be understood by those skilled in the art that the embodiment is an example, and that various modifications are possible in the combination of each component and each treatment process, and that such modifications are within the scope of the present invention. .

100 image coding device 101 block division unit 102 inter prediction unit 103 intra prediction unit 104 decoded image memory 105 prediction method determination unit 106 residual signal generation unit 107 orthogonal transformation/quantization unit 108 bit string code 110 decoded image signal superimposition unit 111 encoded information storage memory 200 image decoding device 201 bit string decoding unit 202 block division unit 203 inter prediction unit 204 intra prediction unit , 205 encoded information storage memory, 206 inverse quantization/inverse orthogonal transform unit, 207 decoded image signal superimposition unit, 208 decoded image memory.

Claims (6)

In an image encoding device that divides an intra block copy reference block into one or more blocks,
a block vector candidate deriving unit for deriving block vector candidates of a target block in a target picture from the encoding information stored in the encoding information storage memory;
a selection unit that selects a selected block vector from the block vector candidates;
With respect to the reference block referenced by the selected block vector, when it is determined that the reference block does not fit in the referable area , the reference block is set so as to refer to the upper left position of the intra block copy reference block immediately before the block to be processed. a reference position correction unit that corrects the reference position,
decoded pixels in the target picture based on the reference position of the reference block,
An image encoding device that acquires a predicted value of the block to be processed from a decoded image memory unit. In an image coding method for dividing an intra block copy reference block into one or more blocks,
a block vector candidate derivation step of deriving a block vector candidate of a block to be processed in a picture to be processed from the coding information stored in the coding information storage memory;
a selecting step of selecting a selected block vector from the block vector candidates;
With respect to the reference block referenced by the selected block vector, when it is determined that the reference block does not fit in the referable area, the reference block is set so as to refer to the upper left position of the intra block copy reference block immediately before the block to be processed. A reference position correction step for correcting the reference position,
decoded pixels in the target picture based on the reference position of the reference block,
An image encoding method for acquiring from a decoded image memory unit as a predicted value of the block to be processed. In an image decoding device that divides an intra block copy reference block into one or more blocks,
a block vector candidate deriving unit for deriving block vector candidates of a target block in a target picture from the encoding information stored in the encoding information storage memory;
a selection unit that selects a selected block vector from the block vector candidates;
With respect to the reference block referenced by the selected block vector, when it is determined that the reference block does not fit in the referable area, the reference block is set so as to refer to the upper left position of the intra block copy reference block immediately before the block to be processed. a reference position correction unit that corrects the reference position,
decoded pixels in the target picture based on the reference position of the reference block,
An image decoding device that acquires from a decoded image memory unit as a predicted value of the block to be processed. In an image decoding method for dividing an intra block copy reference block into one or more blocks,
a block vector candidate derivation step of deriving a block vector candidate of a block to be processed in a picture to be processed from the coding information stored in the coding information storage memory;
a selecting step of selecting a selected block vector from the block vector candidates;
With respect to the reference block referenced by the selected block vector, when it is determined that the reference block does not fit in the referable area, the reference block is changed so as to refer to the upper left position of the intra block copy reference block immediately before the block to be processed. A reference position correction step for correcting the reference position,
decoded pixels in the target picture based on the reference position of the reference block,
An image decoding method for acquiring from a decoded image memory unit as a predicted value of the block to be processed. A storage method for storing a bitstream encoded by an image encoding method that divides an intra block copy reference block into one or more blocks,
The image encoding method comprises:
a block vector candidate derivation step of deriving a block vector candidate of a block to be processed in a picture to be processed from the coding information stored in the coding information storage memory;
a selecting step of selecting a selected block vector from the block vector candidates;
With respect to the reference block referenced by the selected block vector, when it is determined that the reference block does not fit in the referable area, the reference block is set so as to refer to the upper left position of the intra block copy reference block immediately before the block to be processed. A reference position correction step for correcting the reference position,
decoded pixels in the target picture based on the reference position of the reference block,
Obtained from a decoded image memory unit as a prediction value of the block to be processed;
A storage method characterized by: A transmission method for transmitting a bitstream encoded by an image encoding method that divides an intra block copy reference block into one or more blocks,
The image encoding method comprises:
a block vector candidate derivation step of deriving a block vector candidate of a block to be processed in a picture to be processed from the coding information stored in the coding information storage memory;
a selecting step of selecting a selected block vector from the block vector candidates;
With respect to the reference block referenced by the selected block vector, when it is determined that the reference block does not fit in the referable area, the reference block is set so as to refer to the upper left position of the intra block copy reference block immediately before the block to be processed. A reference position correction step for correcting the reference position,
decoded pixels in the target picture based on the reference position of the reference block,
Obtained from a decoded image memory unit as a prediction value of the block to be processed;
A transmission method characterized by:

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