JP6882564B2 - Encoding device, decoding method - Google Patents

Description

The present invention relates to a process of encoding a block included in an image using motion compensation.

As a coding method for compressed recording of moving images, H.I. 264 / MPEG-4 AVC (hereinafter abbreviated as H.264) is known (Non-Patent Document 1). H. In 264, the coding efficiency is improved by performing motion compensation with reference to other pictures as in the conventional coding method. The motion vector can be encoded in units of macroblocks (16 pixels × 16 pixels) or blocks (8 pixels × 8 pixels, etc.). In the coding of the motion vector, the predicted motion vector is calculated using the median value of the motion vector of the surrounding blocks (left, top, upper right), and the error between this and the motion vector to be encoded is encoded. In addition, H. In 264, hierarchical coding can be performed. It is described in the chapter of Annex G Scalable video coding in Non-Patent Document 1. In the case of spatial scalability, instead of the median of the normal motion vector when encoding the motion vector of the extension layer, the motion vector of the block of the base layer is expanded to be the predicted motion vector (hereinafter referred to as the interlayer predicted motion vector). Can be. That is, using motion_prescription_flag, if this value is true, the motion vector obtained by enlarging can be used.

In recent years, H. As a successor to 264, activities to carry out international standardization of more efficient coding methods have started. To this end, JCT-VC (Joint Collaborative Team on Video Coding) was established between ISO / IEC and ITU-T. Here, standardization is being promoted as a High Efficiency Video Coding coding method (hereinafter, abbreviated as HEVC). HEVC has proposed Advanced Motion Vector Prediction (hereinafter referred to as AMVP) as a new coding method for motion vectors (Non-Patent Document 2). In AMVP, not only the median value of the motion vector of the surrounding block is used as the reference motion vector, but also the motion vector of the surrounding block itself is used as the reference motion vector. Further, not only the motion vector of the surrounding blocks but also the motion vector of the block at the same position in the previous picture in the coding order (hereinafter referred to as the time direction predicted motion vector) is included in the predicted motion vector. By collecting motion vectors of the same component from these predicted motion vectors, the target motion vector is reduced, and the closest motion vector is selected from these. A code for identifying the selected motion vector (hereinafter referred to as a prediction vector index code) and a prediction error of the prediction result are encoded. As a result, the coding efficiency is improved.

ISO / IEC14496-10: 2010 Information technology --- Coding of audio-visual objects --Part 10: Advanced Video Coding JCT-VC Contribution JCTVC-A124_r2. doc Internet <http://wfttp3. itu. int / av-arch / jctvc-site / 2010_04_A_Dresden />

In HEVC, when trying to realize hierarchical coding, H.M. You will have to choose whether to refer to the motion vector of the extension layer or the motion vector of the base layer as in 264. However, H. If the reference motion vector is selected as in 264, the above method may be used, but there is a problem that the coding efficiency is not improved because a flag for selecting the prediction vector index code by AMVP and the prediction of the inter-layer motion vector is required. Is occurring.

Therefore, the present invention has been made to solve the above-mentioned problems, and an object of the present invention is to perform coding of a motion vector in an extended layer of hierarchical coding with a simpler configuration and to improve coding efficiency. It is supposed to be.

In order to solve the above-mentioned problems, the coding apparatus of the present invention has the following configuration.

A coding device that hierarchically encodes an image using multiple layers.
In the first layer to which the image to be encoded belongs, the motion vector of the block included in the image that has been encoded before the image to which the block to be encoded belongs and at the position corresponding to the block to be encoded. With a first vector
A second vector, which is a motion vector of a block included in an image in a second layer different from the first layer to which the image to be encoded belongs and at a position corresponding to the block to be encoded,
An acquisition means for acquiring a third vector, which is included in the image in the first layer to which the image to be encoded belongs and is a motion vector of a block around the block to be decoded.
From the first vector, the second vector, and the third vector, a candidate motion vector group to be acquired by the acquisition means is determined, and among the candidate motion vector groups acquired based on the determination. , A determinant that determines the motion vector as the predicted motion vector used to predict the motion vector of the block to be encoded,
A coding means that encodes the identification information of the motion vector determined by the determination means, and
When the second vector exists in the candidate motion vector group, the determining means does not include the first vector as the candidate motion vector group, but instead includes the second vector and the third vector. At least one of the above is determined as the candidate motion vector group, and the motion vector group is determined.
The determining means is a coding device, characterized in that the second vector is arranged in a predetermined order of the candidate motion vector group, and the order of other vectors is determined based on the position of a block.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a coding device and a method for processing data having improved coding efficiency.

The block diagram which shows the structure of the image coding apparatus in Embodiment 1. Detailed block diagram of the motion vector coding unit 102 in the image coding device according to the first embodiment. Detailed block diagram of the motion vector coding unit 105 in the image coding device according to the first embodiment. A flowchart showing a basic layer motion vector coding process in the image coding apparatus according to the first embodiment. A flowchart showing an extended layer motion vector coding process in the image coding apparatus according to the first embodiment. Diagram showing an example of blocks and motion vectors The block diagram which shows the structure of the image decoding apparatus which concerns on Embodiment 2. Detailed block diagram of the motion vector decoding unit 701 according to the second embodiment Detailed block diagram of the motion vector decoding unit 704 according to the second embodiment A flowchart showing a basic layer motion vector decoding process in the image decoding apparatus according to the second embodiment. A flowchart showing an extended layer motion vector decoding process in the image decoding apparatus according to the second embodiment. Detailed block diagram of the motion vector coding unit 105 in the image coding device according to the third embodiment. A flowchart showing an extended layer motion vector coding process in the image coding apparatus according to the third embodiment. Detailed block diagram of the motion vector decoding unit 704 according to the fourth embodiment A flowchart showing an extended layer motion vector coding process in the image coding apparatus according to the fourth embodiment. Diagram showing an example of blocks and motion vectors A block diagram showing a configuration example of computer hardware applicable to the image encoding device and decoding device of the present invention.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings, based on its preferred embodiments. The configuration shown in the following embodiments is only an example, and the present invention is not limited to the illustrated configuration.

<Embodiment 1>
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an image coding apparatus of this embodiment. In FIG. 1, 106 is a terminal for inputting image data. Reference numeral 107 denotes a frame memory for storing the input image data for each picture. Reference numeral 113 denotes a scaling unit, which scales the input image data at a magnification of n / m (n and m are positive numbers). Reference numeral 114 denotes a frame memory for storing scaled image data in picture units. Reference numerals 108 and 115 are prediction units, which cut out image data into a plurality of blocks, perform intra-frame prediction, intra-prediction, inter-prediction by motion compensation, and the like to generate predicted image data. However, the prediction method is not limited to these. Further, the prediction error is calculated from the input image data and the predicted image data and output. When performing inter-prediction, the motion vector is calculated and output by referring to another encoded picture. In addition, information necessary for prediction, for example, information such as an intra prediction mode is also output together with a prediction error. Reference numerals 109 and 116 are conversion / quantization units for obtaining a conversion coefficient by orthogonally converting the prediction error in block units and further performing quantization to obtain a quantization coefficient. 112 and 119 are frame memories for storing the reproduced image data. Reference numerals 111 and 118 are image reproduction units. The quantization coefficient is input in block units, inverse quantization is performed, the conversion coefficient is obtained, and the inverse orthogonal transformation is further performed to reproduce the prediction error. The prediction units 108 and 115 appropriately refer to the frame memory 112 and 119 from the motion vector and the information related to the prediction to generate the predicted image data, and generate and output the reproduced image data from this and the reproduced prediction error. Reference numerals 110 and 117 are coefficient coding units that encode the quantization coefficients output from the conversion / quantization units 109 and 116 to generate quantization coefficient code data.

Reference numeral 100 denotes a motion vector coding device according to the present invention. Reference numerals 101 and 104 are motion vector holding units that hold motion vectors in block units. The motion vector holding unit 104 holds the motion vector generated by the prediction unit 108, and the motion vector holding unit 101 holds the motion vector generated by the prediction unit 115. Reference numerals 102 and 105 are motion vector coding units that encode the motion vectors of the blocks generated by the prediction units 108 and 115 to generate motion vector code data. Reference numeral 103 denotes a motion vector scaling section that changes the motion vector according to the scaling factor of the scaling section 113. Reference numeral 120 denotes a scaling portion, which scales the image data of the frame memory 119 at a scaling factor (m / n) opposite to that of the scaling portion 113.

Reference numerals 121 and 122 are integrated coding units. In addition to generating code data of header information and information related to prediction, the motion vector code data generated by the motion vector coding units 102 and 105 and the quantization coefficient code data generated by the coefficient coding units 110 and 117 are integrated. ..

Here, the frame memory 114, 119, the prediction unit 115, the conversion / quantization unit 116, the coefficient coding unit 117, the image reproduction unit 118, the motion vector holding unit 101, and the motion vector coding unit 102 use the image data of the basic layer. Encode. Further, the frame memories 107 and 112, the prediction unit 108, the conversion / quantization unit 109, the coefficient coding unit 110, the image reproduction unit 111, the motion vector holding unit 104, and the motion vector coding unit 105 code the image data of the expansion layer. To be.

Reference numeral 123 denotes a multiplexing unit that multiplexes the code data of these basic layers and the code data of the extension layer to form a bit stream. Reference numeral 124 denotes a terminal, which is a terminal for outputting the bit stream generated by the multiplexing unit 123 to the outside.

The image coding operation in the image coding apparatus will be described below. First, the coding operation of the basic layer will be described.

The image data for one frame input from the terminal 106 is stored in the frame memory 107. The scaling unit 113 scales the image data stored in the frame memory 107 at a predetermined magnification of n / m. In the case of spatial scalability, n / m is a value less than 1. The scaled image data is stored in the frame memory 114. Further, the scaling factor is input to the scaling unit 120 and the motion vector scaling unit 103.

The prediction unit 115 performs intra-prediction or inter-prediction by motion compensation. The scaling unit 120 scales the image data of the basic layer of the frame memory 119 to m / n times to generate the reference image data of the basic layer. In the case of inter-prediction, the motion vector is calculated by referring to the encoded picture stored in the frame memory 119 and the reference image data of the basic layer. The calculated motion vector is input to the image reproduction unit 118 and the motion vector holding unit 101. The motion vector holding unit 101 holds a motion vector in block units. Further, the prediction unit 115 inputs the generated prediction error to the conversion / quantization unit 116. The quantization coefficient generated by the conversion / quantization unit 116 is input to the coefficient coding unit 117, entropy-coded, and the quantization coefficient code data is generated. The method of entropy coding is not particularly limited, but Golomb coding, arithmetic coding, Huffman coding and the like can be used. In addition, information on the quantization coefficient, motion vector, and prediction is input to the image reproduction unit 118, a reproduction image of the block to be encoded is generated, and the information is stored in the frame memory 119.

The motion vector generated by the prediction unit 115 is encoded by the motion vector coding unit 102 to generate motion vector code data. FIG. 2 shows a detailed block diagram of the motion vector coding unit 102. In FIG. 2, 201 is a terminal, and a motion vector is input from the motion vector holding unit 101. Reference numeral 202 denotes a terminal, and the motion vector of the coded block is input from the prediction unit 115. Reference numeral 203 denotes a motion vector extraction unit, which extracts a motion vector around the block to be encoded or a motion vector of a previously encoded picture through the terminal 201. Reference numeral 204 denotes a motion vector integration unit, which collects motion vectors having the same components and generates a reference motion vector group. Further, in the reference motion vector group, the grouped motion vectors are arranged in a predetermined order. The arrangement method is not particularly limited, but the arrangement is based on the order of the size of the components, the order of the highest probability of occurrence, the position of the extracted blocks, and the like. Any method may be used as long as the same method as that used on the decoding side is used.

Reference numeral 205 denotes a prediction motion vector selection unit, in which the motion vector of the block to be encoded is input from the terminal 202, and the reference motion vector group is input from the motion vector integration unit 204. From the input reference motion vector group, the motion vector closest to the motion vector of the block to be encoded is selected as the predicted motion vector. The identification number for identifying the selected predicted motion vector in the reference motion vector group and the selected predicted motion vector are output. Reference numeral 206 denotes an index coding unit, which encodes the output identification number to generate identification information code data. The method of coding the identification number is not particularly limited, but Golomb coding, arithmetic coding, Huffman coding, or the like can be used. Reference numeral 207 is a prediction unit, which outputs a prediction error when the motion vector of the block to be encoded is predicted by the input predicted motion vector. Reference numeral 208 denotes a motion vector error coding unit that encodes the motion vector prediction error and generates motion vector prediction error code data. The method of encoding the prediction error of the motion vector is not particularly limited, but Golomb coding, arithmetic coding, Huffman coding, or the like can be used. Reference numeral 209 denotes a code forming unit, which forms the identification information code data and the motion vector prediction error code data to generate the motion vector code data. Reference numeral 210 denotes a terminal, which outputs the generated motion vector code code data to the integrated coding unit 122 of FIG.

The motion vector coding operation of the basic layer with the above configuration will be described below.

The motion vector extraction unit 203 inputs the motion vector of the block around the block of the basic layer to be encoded and the motion vector predicted in the time direction via the terminal 201. These motion vectors are input to the motion vector integration unit 204, the components of the motion vectors are compared, and the same motion vectors are put together to generate a reference motion vector group. FIG. 6 shows the state of extraction and integration of motion vectors. 600 represents the picture of the nth extension layer, and 601 represents the picture of the n-1st extension layer. Reference numeral 603 is a block to be encoded, and 604, 605, and 606 are blocks adjacent to the block to be encoded. 607 is a picture of the n-1st expansion layer and represents a block at the same position as block 603. 609 represents the motion vector of the block to be encoded, and 610, 611, 612, and 613 represent the motion vector of each block. Here, when the motion vectors 611 and 612 have the same component, the reference motion vector group becomes the motion vectors 613, 612, and 610.

The generated reference motion vector group is input to the predicted motion vector selection unit 205. The motion vector of the block to be encoded input from the terminal 202 is compared with the motion vector of the reference motion vector group by the predicted motion vector selection unit 205. From the reference motion vector group, the motion vector of the component closest to the motion vector of the block to be encoded is selected as the predicted motion vector. An identification number indicating the order is generated in order to identify the selected motion vector by the reference motion vector group, and the identification number is encoded by the index coding unit 206 to generate the identification information code data. Further, the predicted motion vector is input to the prediction unit 207, predicts the motion vector of the block to be encoded, calculates the prediction error, and outputs the prediction error to the motion vector error coding unit 208. The motion vector error coding unit 208 encodes the prediction error and generates motion vector prediction error code data. The identification information code data and the motion vector prediction error code data are molded by the code forming unit 209 and output from the terminal 210 as motion vector code data.

Returning to FIG. 1, the generated motion vector code data and the quantization coefficient code data generated by the coefficient coding unit 117 are input to the integrated coding unit 122 to generate block unit code data. The generated code data is input to the multiplexing unit 123.

Subsequently, the coding operation of the image data of the expansion layer will be described.

The prediction unit 108 divides the image data stored in the frame memory 107 into blocks, and performs intra-prediction or inter-prediction by motion compensation in block units. In the case of inter-prediction, the motion vector is calculated by referring to the encoded picture stored in the frame memory 112. The calculated motion vector is input to the image reproduction unit 111 and the motion vector holding unit 104. The motion vector holding unit 104 holds the motion vector in block units. Further, the prediction unit 108 inputs the generated prediction error to the conversion / quantization unit 109. The quantization coefficient generated by the conversion / quantization unit 109 is input to the coefficient coding unit 110, and is entropy-encoded in the same manner as the coefficient coding unit 117 to generate the quantization coefficient code data. Further, information on the quantization coefficient, motion vector, and prediction is input to the image reproduction unit 111, a reproduced image of the block to be encoded is generated in the same manner as the image reproduction unit 118, and is stored in the frame memory 112.

The motion vector generated by the prediction unit 108 is encoded by the motion vector coding unit 105 to generate motion vector code data. Prior to coding the motion vector in the motion vector coding unit 105, the motion vector scaling unit 103 transfers the motion vector at the position of the block of the basic layer corresponding to the block of the expansion layer to be encoded from the motion vector holding unit 101. Extract. The extracted motion vector is multiplied by m / n according to the scaling factor (n / m) output from the scaling unit 113, and is output to the motion vector coding unit 105 as an inter-layer predicted motion vector. FIG. 6 shows the state of extraction and integration of motion vectors. 602 represents a picture of the corresponding base layer of the nth extension layer. 608 represents a block at a position corresponding to the block to be encoded in the expansion layer. 614 represents the motion vector of block 608 of the base layer. The motion vector 614 is scaled to a inter-layer predicted motion vector with the same accuracy as the resolution of the extended layer. Here, when the motion vectors 611 and 612 and the inter-layer predicted motion vector have the same component, the reference motion vector group becomes the inter-layer predicted motion vector, the motion vector 613, 610.

FIG. 3 shows a detailed block diagram of the motion vector coding unit 105. In FIG. 3, blocks that realize the same functions as the blocks of FIG. 2 are given the same numbers, and the description thereof will be omitted. Reference numeral 301 denotes a terminal, and an inter-layer predicted motion vector is input from the motion vector scaling unit 103. Reference numeral 303 denotes a motion vector extraction unit, which extracts the motion vector around the coded block of the expansion layer or the motion vector of the previously encoded picture through the terminal 201, and inputs the inter-layer predicted motion vector from the terminal 301. .. Reference numeral 304 denotes a motion vector integration unit, which collects motion vectors having the same components and generates a reference motion vector group. Further, in the reference motion vector group, the grouped motion vectors are arranged in a predetermined order. The arrangement is not particularly limited, but the inter-layer predicted motion vector is placed at the beginning. Other than that, they may be arranged based on the order of the size of the components, the order of the highest probability of occurrence, the position of the extracted blocks, and the like. The terminal 201 is connected to the motion vector holding unit 104, the terminal 202 is connected to the prediction unit 108, and the terminal 210 is connected to the integrated coding unit 121.

The motion vector coding operation of the expansion layer with the above configuration will be described below.

The motion vector extraction unit 303 inputs the motion vector of the block around the block of the basic layer to be encoded, the time direction predicted motion vector, and the inter-layer predicted motion vector. These motion vectors are compared with each other by the motion vector integration unit 304, and the same motion vectors are put together to generate a reference motion vector group. In the reference motion vector group, the grouped motion vectors are arranged in a predetermined order. The generated reference motion vector group is input to the predicted motion vector selection unit 205. Hereinafter, similarly to the motion vector coding unit 102 of the basic layer, the motion vector of the block to be encoded is compared with the motion vector of the reference motion vector group, the predicted motion vector is selected, the identification number is generated, and the code is used. To generate identification information code data. The prediction error of the motion vector of the block to be encoded is calculated, encoded, and the motion vector prediction error code data is generated. The identification information code data and the motion vector prediction error code data are molded by the code forming unit 209 and output from the terminal 210 as motion vector code data.

Returning to FIG. 1, the generated motion vector code data is input to the integrated coding unit 121 for the quantization coefficient code data generated by the coefficient coding unit 110, and the code data for each block is generated. The generated code data is input to the multiplexing unit 123.

The multiplexing unit 123 multiplexes these code data according to a predetermined format and outputs the code data as a bit stream to the outside from the terminal 124.

FIG. 4 is a flowchart showing a motion vector coding process of the basic layer in the image coding apparatus according to the first embodiment. First, in step S401, the motion vector of the block to be encoded in the basic layer is input and held for reference in the subsequent stage. In step S402, among the motion vectors of the coded base layer in which the motion vectors of the blocks surrounding the block to be encoded in the base layer or the blocks at the same position of the coded picture of the base layer are held. Extract. In step S403, the motion vectors of the same component are grouped by the motion vectors extracted in step S402 and rearranged in a predetermined order to generate a reference motion vector group. In step S404, the reference motion vector group generated in step S403 and the motion vector of the coded target block of the basic layer are compared, the closest motion vector is selected as the predicted motion vector of the basic layer, and identification information is generated. .. In step S405, the motion vector to be encoded is predicted. The prediction error is calculated from the motion vector. In step S406, the identification information generated in step S404 is encoded. In step S407, the prediction error of the motion vector of the basic layer is encoded.

Further, FIG. 5 is a flowchart showing a motion vector coding process of the expansion layer in the image coding apparatus according to the first embodiment. In FIG. 5, the steps for realizing the same function as the block of FIG. 4 are numbered the same, and the description thereof will be omitted. First, in step S501, the motion vector of the block to be encoded in the expansion layer is input and held for reference in the subsequent stage. In step S502, the motion vector of the block around the block to be encoded in the expansion layer or the block at the same position in the picture of the encoded expansion layer is extracted from the motion vector of the retained expansion layer. In step S503, the motion vector of the block of the basic layer corresponding to the position of the coded block of the extended layer is extracted. In step S504, the motion vector of the extracted basic layer is scaled to calculate the inter-layer predicted motion vector. In step S505, the motion vectors of the same components are grouped by the motion vector extracted in step S502 and the inter-layer predicted motion vector, rearranged in a predetermined order, and a reference motion vector group is generated. Hereinafter, similarly to the motion vector coding of the basic layer of FIG. 4, the predicted motion vector is determined and the identification information is generated in steps S504 to S506. Further, the prediction error is calculated from the predicted motion vector. The generated identification information and the prediction error of the motion vector are encoded.

With the above configuration and operation, in the motion vector coding of the extended layer, efficient coding can be performed using the motion vector of the basic layer. When the magnification of the scaling is 1, the scaling portions 113 and 120 and the motion vector scaling portion 103 can be omitted.

It is also possible for the motion vector integration unit 204 to always assign the inter-layer predicted motion vector to the beginning of the reference motion vector group. As a result, it is possible to further improve the coding efficiency by making it easy to assign a short code to the inter-layer predicted motion vector that is very likely to be referred to.

Note that the motion vector extraction unit 203 inputs the motion vector of the block at the same position of the time-direction predicted motion vector-encoded picture, but the present invention is not limited to this. For example, when the inter-layer predicted motion vector exists, the input of the time direction predicted motion vector may be omitted.

Although the motion vector integration unit 304 has described the case where the inter-layer predicted motion vector is arranged at the head, the order following the time direction predicted motion vector may be used. Further, it is not necessary to determine the arrangement in the same manner as the motion vector integration unit 204.

In order to improve the coding efficiency, the motion vector integration unit collects motion vectors having the same components, but the present invention is not limited to this, and a fixed number of motion vectors may be selected. Furthermore, the motion vector integration unit may be omitted.

Further, the basic layer coding device and the expansion layer coding device may be separately provided, and the scaling unit 113 and the scaling unit 120 may be externally provided.

The block at the position shown in FIG. 6 was referred to as the motion vector of the reference motion vector group, but the present invention is not limited to this. For example, a motion vector of a block adjacent to the right of the block 604 may be added, or a motion vector consisting of the median values of these motion vectors may be added. Also, the motion vectors referenced from the base layer are not limited to the same position. As shown in FIG. 16, the motion vector 1604 of the block 1601 below the block 608, the motion vector 1605 of the block 1602 at the lower right, and the motion vector 1606 of the block 1603 on the right may be referred to. Further, the motion vector of another block may be referred to.

<Embodiment 2>
FIG. 7 is a block diagram showing a configuration of an image decoding device according to a second embodiment of the present invention. In this embodiment, decoding of the coded data generated in the first embodiment will be described as an example.

Reference numeral 706 is a terminal for inputting an encoded bit stream. Reference numeral 707 is a separation unit that separates the bit stream into the code data of the basic layer and the code data of the extension layer. The separation unit 707 performs the reverse operation of the multiplexing unit 123 of FIG. Reference numerals 708 and 715 are integrated decoding units, which decode the code data of the header information and the information related to the prediction for the basic layer and the extended layer, separate the quantization coefficient code data and the motion vector code data, and output them to the subsequent stage. Reference numerals 709 and 716 are coefficient decoding units, which perform operations opposite to those of the coefficient coding units 117 and 110 in FIG. 1 to reproduce the quantization coefficient. Reference numerals 710 and 717 are inverse quantization / inverse transformation units. With respect to the input quantization coefficient, the operation opposite to that of the conversion / quantization units 116 and 109 in FIG. 1 is performed, the orthogonal transformation coefficient is reproduced by inverse quantization, and a prediction error is generated by inverse orthogonal transformation.

Reference numeral 700 denotes a motion vector decoding device according to the present invention. Reference numerals 701 and 704 are motion vector decoding units that decode the motion vector code data and reproduce the motion vector of the block to be decoded. Reference numerals 702 and 705 are motion vector holding units that hold motion vectors in block units. Reference numeral 706 is a motion vector scaling section that scales the motion vector according to the same scaling factor as that of the scaling section 113 in FIG. The calculation of the variable magnification is not particularly limited. The ratio of the resolution of the basic layer to the resolution of the extended layer may be calculated, or a predetermined value may be set.

The 712, 713, 719, and 720 are frame memories, and store the image data of the reproduced picture.

Reference numerals 711 and 718 are image reproduction units, which input a motion vector, refer to the image data of the decoded picture to perform motion compensation, and reproduce the image data using the decoded prediction error. Reference numeral 714 is a scaling unit that scales the image data of the basic layer according to the same scaling factor as that of the scaling unit 113 in FIG. The calculation of the variable magnification is not particularly limited. The ratio of the resolution of the basic layer to the resolution of the extended layer may be calculated, or a predetermined value may be set. 721 and 722 are terminals, the terminal 721 outputs the image data of the basic layer, and the terminal 722 outputs the image data of the expansion layer.

Here, the integrated decoding unit 708, the coefficient decoding unit 709, the inverse quantization / inverse conversion unit 710, the motion vector decoding unit 701, the motion vector holding unit 702, the image reproduction unit 711, the frame memory 712, and 713 are the code data of the basic layer. Is decoded and the image data of the basic layer is reproduced. Further, the integrated decoding unit 715, the coefficient decoding unit 716, the inverse quantization / inverse conversion unit 717, the motion vector decoding unit 704, the motion vector holding unit 705, the image reproduction unit 718, the frame memory 719, and 720 generate the code data of the expansion layer. Decode and reproduce the image data of the expansion layer.

The image decoding operation in the image decoding device will be described below. In this embodiment, the bitstream generated in the first embodiment is decoded.

In FIG. 7, the bit stream input from the terminal 706 is input to the separation unit 707 and separated into the code data of the basic layer and the code data of the extension layer, the former to the integrated decoding unit 708 and the latter to the integrated decoding unit 715. Entered.

First, the operation of decoding the code data of the basic layer will be described. The coded data of the basic layer is input to the integrated decoding unit 708. The integrated decoding unit 708 decodes the code data of the header information and the information related to the prediction, separates the quantization coefficient code data and the motion vector code data, inputs the motion vector code data to the motion vector decoding unit 701, and inputs the quantization coefficient. The code data is input to the coefficient decoding unit 709.

The coefficient decoding unit 709 decodes the quantization coefficient code data and reproduces the quantization coefficient. The regenerated quantization coefficient is input to the inverse quantization / inverse transformation unit 710, the inverse quantization is performed to generate the orthogonal transformation coefficient, and the inverse orthogonal transformation is further performed to reproduce the prediction error. The reproduced prediction error is input to the image reproduction unit 711.

The motion vector decoding unit 701 decodes the motion vector code data and decodes the motion vector of the block to be decoded in the basic layer. FIG. 8 shows a detailed block diagram of the motion vector decoding unit 701. In FIG. 8, 801 is a terminal, and motion vector code data of the block to be decoded is input from the integrated decoding unit 708. Reference numeral 802 is a terminal, and a motion vector is input from the motion vector holding unit 702. Reference numeral 803 is a motion vector extraction unit, which extracts the motion vector around the decoding target block of the basic layer or the motion vector of the previously decoded picture through the terminal 802. Reference numeral 804 is a motion vector integration unit, which performs the same operation as the motion vector integration unit 204 of FIG. 2, collects motion vectors having the same components, and generates a reference motion vector group. Reference numeral 805 is a code separation unit, which separates the identification information code data and the motion vector prediction error code data from the motion vector code data. Reference numeral 806 is an index decoding unit, which decodes the identification information code data and reproduces the identification information. The index decoding unit 806 performs the reverse operation of the index coding unit 206 of FIG. 2 to perform decoding. Reference numeral 807 is a motion vector error decoding unit, which decodes the motion vector prediction error code data and reproduces the motion vector prediction error of the block to be decoded. The motion vector error decoding unit 807 decodes by performing the reverse operation of the motion vector error coding unit 208 of FIG. Reference numeral 808 is a predicted motion vector selection unit. A predicted motion vector is selected from the reference motion vector group using the reproduced identification information. Reference numeral 809 is a motion vector reproduction unit, which reproduces the motion vector of the decoding target block of the basic layer from the prediction error between the selected predicted motion vector and the reproduced motion vector. Reference numeral 810 is a terminal, and the reproduced motion vector is output to the image reproduction unit 711 and the motion vector holding unit 702 in FIG. 7.

The decoding operation of the motion vector of the basic layer with the above configuration will be described below. The motion vector code data of the decoding target block of the basic layer input from the terminal 801 is input to the code separation unit 805 and separated into the identification information code data and the motion vector prediction error code data. The former is input to the index decoding unit 806, and the latter is input to the motion vector error decoding unit 807. The index decoding unit 806 decodes the identification information code data and reproduces the identification information. Further, the motion vector error decoding unit 807 decodes the motion vector prediction error code data and reproduces the motion vector prediction error of the decoding target block of the basic layer. Further, as shown in FIG. 6, the motion vector extraction unit 803 extracts the motion vector of the block around the block of the basic layer to be decoded and the time direction prediction motion vector from the motion vector holding unit 702 via the terminal 802. The extracted motion vector is input to the motion vector integration unit 804, and a reference motion vector group is generated in the same manner as the motion vector integration unit 204 of FIG.

The predicted motion vector selection unit 808 inputs identification information from the index decoding unit 806, and selects a predicted motion vector from the reference motion vector group. The selected predicted motion vector is input to the motion vector reproduction unit 809 together with the prediction error of the motion vector of the decoding target block of the reproduced basic layer. The motion vector reproduction unit 809 reproduces the motion vector of the block to be decoded from the reproduced prediction error and the predicted motion vector. The reproduced motion vector is output via the terminal 810.

Returning to FIG. 7, the reproduced motion vector is input to the image reproduction unit 711 and the motion vector holding unit 702. The motion vector holding unit 702 stores the motion vector in block units. The image reproduction unit 711 calculates the predicted image data of the decoding target block of the basic layer from the frame memory 713 using the reproduced motion vector. Further, the prediction error reproduced by the inverse quantization / inverse transformation unit 710 is input, and the image data of the basic layer is reproduced using the predicted image data. The reproduced image data of the basic layer is stored in the frame memory 712 and the frame memory 713 and used for reference. The reproduced image data of the basic layer is output from the terminal 721.

Subsequently, the operation of decoding the code data of the expansion layer will be described. Prior to decoding the motion vector by the motion vector decoding unit 704, the motion vector scaling unit 703 extracts the motion vector at the position of the block of the basic layer corresponding to the block of the expansion layer to be decoded from the motion vector holding unit 702. The extracted motion vector is multiplied by m / n according to the variable magnification (n / m), and is output to the motion vector decoding unit 704 as an inter-layer predicted motion vector.

The coded data of the expansion layer is input to the integrated decoding unit 715. The integrated decoding unit 715 decodes the code data of the header information and the information related to the prediction, separates the quantization coefficient code data and the motion vector code data, inputs the motion vector code data to the motion vector decoding unit 704, and inputs the quantization coefficient. The code data is input to the coefficient decoding unit 716.

The coefficient decoding unit 716 decodes the quantization coefficient code data and reproduces the quantization coefficient. The regenerated quantization coefficient is input to the inverse quantization / inverse transformation unit 717, the inverse quantization is performed to generate the orthogonal transformation coefficient, and the inverse orthogonal transformation is further performed to reproduce the prediction error. The reproduced prediction error is input to the image reproduction unit 718.

The motion vector decoding unit 704 decodes the motion vector code data and decodes the motion vector of the block to be decoded in the expansion layer. FIG. 9 shows a detailed block diagram of the motion vector decoding unit 704. In FIG. 9, blocks that realize the same functions as the blocks of FIG. 8 are given the same numbers, and description thereof will be omitted. In FIG. 9, 901 is a terminal, and a motion vector is input from the motion vector scaling unit 703. Reference numeral 903 is a motion vector extraction unit, which inputs a motion vector around the decoding target block of the expansion layer or a motion vector of a previously encoded picture through the terminal 901 as shown in FIG. Further, the inter-layer predicted motion vector input from the terminal 901 is input. Reference numeral 904 is a motion vector integration unit, which performs the same operation as the motion vector integration unit 904 of FIG. 8, collects motion vectors having the same components, and generates a reference motion vector group. In the reference motion vector group, the grouped motion vectors are arranged in a predetermined order. The arrangement is not particularly limited, but the inter-layer predicted motion vector is placed at the beginning. Other than that, they may be arranged based on the order of the size of the components, the order of the highest probability of occurrence, the position of the extracted blocks, and the like. The terminal 801 is connected to the integrated decoding unit 715, the terminal 802 is connected to the motion vector holding unit 705, and the terminal 810 is connected to the motion vector holding unit 705 and the image reproduction unit 718.

The decoding operation of the motion vector of the expansion layer with the above configuration will be described below. The motion vector extraction unit 903 inputs the motion vector of the block around the block of the expansion layer to be decoded and the time direction prediction motion vector from the motion vector holding unit 705 via the terminal 802. Further, the inter-layer predicted motion vector is input from the terminal 901. These motion vectors are input to the motion vector integration unit 904, and a reference motion vector group is generated in the same manner as the motion vector integration unit 804 of FIG. Hereinafter, similarly to the motion vector decoding unit 701 of the basic layer, the predicted motion vector is selected from the identification information and the reference motion vector group. The motion vector of the decoding target block of the expansion layer is reproduced by the prediction error of the selected predicted motion vector and the motion vector of the decoding target block of the reproduced expansion layer. The reproduced motion vector is output via the terminal 810.

Returning to FIG. 7, the reproduced motion vector is input to the image reproduction unit 718 and the motion vector holding unit 705. The motion vector holding unit 705 stores the motion vector in block units. The image reproduction unit 718 reads the corresponding image data from the frame memory 720 or the frame memory 713 using the reproduced motion vector, and inputs the image data scaled by the scaling unit 714. From these image data, the predicted image data of the decoding target block of the expansion layer is calculated. Further, the prediction error reproduced by the inverse quantization / inverse transformation unit 717 is input, and the image data of the expansion layer is reproduced using the predicted image data. The reproduced image data of the expansion layer is stored in the frame memory 719 and the frame memory 720 and used for reference. The reproduced image data of the expansion layer is output from the terminal 722.

FIG. 10 is a flowchart showing a motion vector decoding process of the basic layer in the image decoding apparatus according to the second embodiment. First, in step S1001, the motion vector of the blocks around the block to be decoded in the basic layer and the motion vector holding the predicted motion vector in the time direction are extracted. In step S1002, the motion vectors of the same component are grouped by the motion vectors extracted in step S1001 and rearranged in a predetermined order to generate a reference motion vector group. In step S1003, the identification information code data is decoded and the identification information is reproduced. In step S1004, the predicted motion vector is selected from the reference motion vector group generated in step S1002 based on the identification information reproduced in step S1003. In step S1005, the motion vector prediction error code data is decoded, and the motion vector prediction error of the block to be decoded in the basic layer is reproduced. In step S1006, the motion vector of the decoding target block of the basic layer is reproduced from the prediction error of the predicted motion vector selected in step S1004 and the motion vector reproduced in step S1005. In step S1007, the reproduced motion vector is output and further retained for reference in a later stage.

Further, FIG. 11 is a flowchart showing a motion vector decoding process of the expansion layer in the image coding apparatus according to the second embodiment. In FIG. 11, the steps for realizing the same function as the block of FIG. 10 are numbered the same, and the description thereof will be omitted. First, in step S1101, the block around the block to be decoded of the expansion layer or the time-direction predicted motion vector of the expansion layer is extracted from the motion vector of the decoded expansion layer held. In step S1102, the motion vector of the block of the basic layer corresponding to the position of the block to be decoded of the expansion layer is extracted. In step S1103, the motion vector of the extracted basic layer is scaled to calculate the inter-layer predicted motion vector. In step S1104, the motion vectors of the same components are grouped by the motion vector extracted in step S1102 and the inter-layer predicted motion vector, rearranged in a predetermined order, and a reference motion vector group is generated. In step S1105, the identification information code data is decoded and the identification information is reproduced. In step S1106, the predicted motion vector is selected from the reference motion vector group generated in step S1104 based on the reproduced identification information. Hereinafter, the motion vector prediction error code data is decoded and the motion vector prediction error is reproduced in the same manner as in the motion vector decoding of the basic layer of FIG. The motion vector of the decoding target block of the expansion layer is reproduced, output, and held from the selected predicted motion vector and the prediction error of the motion vector.

With the above configuration and operation, it is possible to efficiently decode the encoded bit stream using the motion vector of the basic layer generated in the first embodiment and obtain a reproduced image. When the magnification of the scaling is 1, the scaling section 714 and the motion vector scaling section 703 can be omitted.

It is also possible for the motion vector integration unit 904 to always assign the inter-layer predicted motion vector to the beginning of the reference motion vector group. This makes it easier to assign a short code to the inter-layer predicted motion vector that is most likely to be referenced, which makes it possible to further improve the coding efficiency.

The motion vector extraction unit 903 has input the time-direction predicted motion vector, but the present invention is not limited to this. For example, when the inter-layer predicted motion vector exists, the input of the time direction predicted motion vector may be omitted.

Although the motion vector integration unit 904 has described the case where the inter-layer predicted motion vector is arranged at the head, the order following the time direction predicted motion vector may be used. Further, it is not necessary to determine the arrangement in the same manner as the motion vector integration unit 204.

In the present embodiment, the scaling factor is input from the motion vector scaling unit 703, but the ratio is not limited to this, and the ratio of the resolution of the basic layer and the resolution of the extended layer may be calculated individually, or a predetermined value. May be set.

In order to improve the coding efficiency, the motion vector integration unit collects motion vectors having the same components, but the present invention is not limited to this, and a fixed number of motion vectors may be selected. Furthermore, the motion vector integration unit may be omitted.

Further, the decoding device of the basic layer and the decoding device of the extended layer may be separately provided, and the scaling unit 714 may be externally provided.

The block at the position shown in FIG. 6 was referred to as the motion vector of the reference motion vector group, but the present invention is not limited to this. For example, a motion vector of a block adjacent to the right of the block 604 may be added, or a motion vector consisting of the median values of these motion vectors may be added. Also, the motion vectors referenced from the base layer are not limited to the same position. As shown in FIG. 16, the motion vector 1604 of the block 1601 below the block 608, the motion vector 1605 of the block 1602 at the lower right, and the motion vector 1606 of the block 1603 on the right may be referred to. Further, the motion vector of another block may be referred to.

<Embodiment 3>
In the present embodiment, the image coding apparatus has the same configuration as that of FIG. 1 of the first embodiment. However, the configuration of the motion vector coding unit 105 of the expansion layer is different. Therefore, the coding related to the basic layer and the coding of the quantization coefficient of the extended layer are the same as those in the first embodiment, and the description thereof will be omitted.

FIG. 12 is a block diagram showing a detailed configuration of the motion vector coding unit 105 of the present embodiment. In FIG. 12, the same numbers are assigned to the parts that perform the same functions as those in FIG. 3 of the first embodiment, and the description thereof will be omitted. Reference numeral 1201 is a terminal, and an inter-layer predicted motion vector is input from the motion vector scaling unit 103 in the same manner as the terminal 301 in FIG. Reference numeral 1203 is a motion vector extraction unit, which extracts the motion vector around the coded block of the expansion layer input from the terminal 201 or the motion vector of the previously encoded picture. Reference numeral 1205 is a predicted motion vector selection unit. The motion vector of the block to be encoded in the expansion layer is input from the terminal 202, the reference motion vector group is input from the motion vector integration unit 204, and the inter-layer predicted motion vector is input from the terminal 1201. From the input reference motion vector group, the motion vector closest to the motion vector of the block to be encoded is selected as the predicted motion vector.

The motion vector coding operation of the expansion layer with the above configuration will be described below.

The motion vector extraction unit 1203 extracts the motion vector around the coded block of the expansion layer shown in FIG. 6 or the motion vector of the previously encoded picture. The extracted motion vector is input to the motion vector integration unit 304. The motion vector integration unit 304 collects motion vectors having the same components with the input motion vectors in the same manner as in the first embodiment, and generates a reference motion vector group. The predicted motion vector selection unit 1205 selects a motion vector most similar to the motion vector of the coded block as the predicted motion vector from the input reference motion vector group and the inter-layer predicted motion vector. Outputs identification information that identifies the selected predicted motion vector and the predicted motion vector.

Here, the difference from the first embodiment is that the inter-layer predicted motion vector is a candidate for selection independently of the reference motion vector group. Therefore, there may be motion vectors having the same component in the reference motion vector group. In this case, the predicted motion vector selection unit 1205 selects the inter-layer predicted motion vector when the inter-layer predicted motion vector and the vector in the reference motion vector group can be selected as the predicted motion vector.

Hereinafter, the identification information is encoded by the index coding unit 206 as in the first embodiment. Further, the prediction unit 207 calculates a prediction error from the motion vector of the coded block and the predicted motion vector, and the motion vector error coding unit 208 encodes the prediction error.

FIG. 13 is a flowchart showing a motion vector coding process of the expansion layer in the image coding apparatus according to the third embodiment. In FIG. 13, the steps for realizing the same function as the block of FIG. 4 are numbered the same, and the description thereof will be omitted. First, steps S501 to S504 are the same as those in the first embodiment. That is, the motion vector around the coded block of the extension layer or the motion vector of the previously encoded picture and the inter-layer predicted motion vector are calculated. In step S1301, the motion vectors of the same components for the motion vectors around the coded block of the expansion layer or the motion vectors of the previously encoded picture are grouped and rearranged in a predetermined order to generate a reference motion vector group. To do. In step S1302, the inter-layer predicted motion vector is added to the beginning of the generated reference motion vector group. In step S404, the predicted motion vector is selected from the reference motion vector group as in the first embodiment. If the predicted motion vector has the same component as the inter-layer predicted motion vector in step S1303, the process proceeds to step S1304. If not, the process proceeds to step S405. In step S1304, the inter-layer predicted motion vector is selected as the predicted motion vector. This prevents other motion vectors with the same component from being selected. Hereinafter, the motion vector prediction error is calculated, the identification information is coded, and the motion vector prediction error is coded in steps S405 to S407 in the same manner as in the motion vector coding process of the expansion layer of FIG. 3 of the first embodiment.

With the above configuration and operation, in the motion vector coding of the extended layer, the motion vector of the basic layer can be used preferentially over other motion vectors for efficient coding. This is because the inter-layer predicted motion vector has a very high correlation with the motion vector of the block of the expansion layer.

The block at the position shown in FIG. 6 was referred to as the motion vector of the reference motion vector group, but the present invention is not limited to this. For example, a motion vector of a block adjacent to the right of the block 604 may be added, or a motion vector consisting of the median values of these motion vectors may be added.

In order to improve the coding efficiency, the motion vector integration unit collects motion vectors having the same components, but the present invention is not limited to this, and a fixed number of motion vectors may be selected. Furthermore, the motion vector integration unit may be omitted.

The block at the position shown in FIG. 6 was referred to as the motion vector of the reference motion vector group, but the present invention is not limited to this.

<Embodiment 4>
In the present embodiment, the image coding apparatus has the same configuration as that of FIG. 7 of the second embodiment. However, the configuration of the motion vector decoding unit 704 of the expansion layer is different. Therefore, the decoding related to the basic layer and the decoding of the quantization coefficient of the extended layer are the same as those in the second embodiment, and the description thereof will be omitted. Further, in the present embodiment, decoding of the coded data generated in the third embodiment will be described as an example.

FIG. 14 is a block diagram showing a detailed configuration of the motion vector decoding unit 704 of the present embodiment. In FIG. 14, the same numbers are assigned to the parts that perform the same functions as those in FIG. 9 of the second embodiment, and the description thereof will be omitted. Similar to the terminal 901 of FIG. 9, the terminal 1401 inputs the inter-layer predicted motion vector from the motion vector scaling unit 703. Reference numeral 1403 is a motion vector extraction unit, which extracts a motion vector around the coded block of the expansion layer shown in FIG. 6 or a motion vector of a previously encoded picture in the same manner as the motion vector extraction unit 1203 of the third embodiment. To do. Reference numeral 1405 is a predicted motion vector selection unit, which selects a predicted motion vector from the inter-layer predicted motion vector and the reference motion vector group according to the identification information from the predicted motion vector.

The motion vector coding operation of the expansion layer with the above configuration will be described below.

The motion vector extraction unit 1403 extracts the motion vector around the decoding target block of the expansion layer shown in FIG. 6 or the motion vector of the previously encoded picture. The extracted motion vector is input to the motion vector integration unit 804. The motion vector integration unit 804 collects motion vectors having the same components with the input motion vectors in the same manner as in the second embodiment, and generates a reference motion vector group. Further, as in the second embodiment, the index decoding unit 806 decodes the identification information code data and reproduces the identification information. The predicted motion vector selection unit 1405 selects a predicted motion vector from the inter-layer predicted motion vector or the reference motion vector group according to the identification information. Hereinafter, as in the second embodiment, the motion vector to be decoded in the expansion layer is reproduced from the prediction error of the motion vector and the selected predicted motion vector.

FIG. 15 is a flowchart showing a motion vector decoding process of the expansion layer in the image decoding apparatus according to the fourth embodiment. In FIG. 15, the steps for realizing the same function as the block of FIG. 11 are numbered the same, and the description thereof will be omitted. First, steps S1101 to S1103 are the same as those in the second embodiment. That is, the motion vector around the decoding target block of the expansion layer or the motion vector of the previously decoded picture and the inter-layer predicted motion vector are calculated. In step S1501, the motion vectors having the same components for the motion vector around the decoding target block of the expansion layer or the motion vector of the previously decoded picture are put together and rearranged in a predetermined order to generate a reference motion vector group. In step S1502, the inter-layer predicted motion vector is added to the beginning of the generated reference motion vector group. Hereinafter, the processes of steps S1105 to S1007 are performed in the same manner as the motion vector decoding process of the expansion layer of FIG. 11 of the second embodiment. That is, the identification information is decoded, the predicted motion vector is selected, the motion vector prediction error is reproduced, and the motion vector of the decoding target block of the expansion layer is reproduced.

With the above configuration and operation, in the motion vector decoding of the extended layer, the motion vector of the basic layer can be used more positively than the other motion vectors to decode the code data encoded with a smaller amount of code. This is because the inter-layer predicted motion vector has a very high correlation with the motion vector of the block of the expansion layer.

In order to improve the coding efficiency, the motion vector integration unit collects motion vectors having the same components, but the present invention is not limited to this, and a fixed number of motion vectors may be selected. Furthermore, the motion vector integration unit may be omitted.

The block at the position shown in FIG. 6 was referred to as the motion vector of the reference motion vector group, but the present invention is not limited to this.

<Embodiment 5>
In the above embodiment, each processing unit shown in FIGS. 1, 2, 3, 7, 7, 8, 9, 12, and 14 has been described as being configured by hardware. However, the processing performed by each processing unit shown in these figures may be configured by a computer program.

FIG. 17 is a block diagram showing a configuration example of computer hardware applicable to the image display device according to each of the above embodiments.

The CPU 1701 controls the entire computer by using the computer programs and data stored in the RAM 1702 and the ROM 1703, and also executes the above-described processes as those performed by the image processing apparatus according to each of the above embodiments. That is, the CPU 1701 functions as each processing unit shown in FIGS. 1, 2, 3, 7, 8, 9, 9, 12, and 14.

The RAM 1702 has an area for temporarily storing computer programs and data loaded from the external storage device 1706, data acquired from the outside via the I / F (interface) 1709, and the like. Further, the RAM 1702 has a work area used by the CPU 1701 to execute various processes. That is, the RAM 1702 can be allocated as a frame memory, for example, and various other areas can be provided as appropriate.

The ROM 1703 stores the setting data of the computer, the boot program, and the like. The operation unit 1704 is composed of a keyboard, a mouse, and the like, and various instructions can be input to the CPU 1701 by being operated by a user of the computer. The display unit 1705 displays the processing result by the CPU 1701. The display unit 1705 is composed of, for example, a liquid crystal display.

The external storage device 1706 is a large-capacity information storage device represented by a hard disk drive device. The external storage device 1706 is used to enable the CPU 1701 to realize the functions of the OS (operating system) and the parts shown in FIGS. 1, 2, 3, 7, 7, 8, 9, 12, and 14. The computer program is saved. Further, each image data as a processing target may be stored in the external storage device 1706.

The computer programs and data stored in the external storage device 1706 are appropriately loaded into the RAM 1702 according to the control by the CPU 1701 and become the processing target by the CPU 1701. A network such as a LAN or the Internet, or other devices such as a projection device or a display device can be connected to the I / F 1707, and the computer acquires and sends various information via the I / F 1707. Can be done. 1708 is a bus connecting the above-mentioned parts.

The CPU 1701 plays a central role in controlling the operation described in the above-mentioned flowchart for the operation having the above configuration.

<Other Embodiments>
An object of the present invention is also achieved by supplying a storage medium in which a computer program code that realizes the above-mentioned functions is recorded to a system, and the system reads and executes the computer program code. In this case, the computer program code itself read from the storage medium realizes the function of the above-described embodiment, and the storage medium storing the computer program code constitutes the present invention. It also includes cases where the operating system (OS) running on the computer performs part or all of the actual processing based on the instructions in the code of the program, and the processing realizes the above-mentioned functions. ..

Further, it may be realized in the following form. That is, the computer program code read from the storage medium is written to the memory provided in the function expansion card inserted in the computer or the function expansion unit connected to the computer. Then, based on the instruction of the code of the computer program, the function expansion card, the CPU provided in the function expansion unit, or the like performs a part or all of the actual processing to realize the above-mentioned function.

When the present invention is applied to the storage medium, the storage medium stores the code of the computer program corresponding to the flowchart described above.

Claims (1)

A coding device that hierarchically encodes an image using multiple layers.
In the first layer to which the image to be encoded belongs, the motion vector of the block included in the image that has been encoded before the image to which the block to be encoded belongs and at the position corresponding to the block to be encoded. With a first vector
A second vector, which is a motion vector of a block included in an image in a second layer different from the first layer to which the image to be encoded belongs and at a position corresponding to the block to be encoded,
An acquisition means for acquiring a third vector, which is included in the image in the first layer to which the image to be encoded belongs and is a motion vector of a block around the block to be decoded.
From the first vector, the second vector, and the third vector, a candidate motion vector group to be acquired by the acquisition means is determined, and among the candidate motion vector groups acquired based on the determination. , A determinant that determines the motion vector as the predicted motion vector used to predict the motion vector of the block to be encoded,
A coding means that encodes the identification information of the motion vector determined by the determination means, and
When the second vector exists in the candidate motion vector group, the determining means does not include the first vector as the candidate motion vector group, but instead includes the second vector and the third vector. At least one of the above is determined as the candidate motion vector group, and the motion vector group is determined.
The determining means is a coding device, characterized in that the second vector is arranged in a predetermined order of the candidate motion vector group, and the order of other vectors is determined based on the position of a block.

Images