JP7457929B2 - Image decoding device and image encoding device - Google Patents

Description

The present invention relates to an image encoding method and an image decoding method.

In the HEVC (High Efficiency Video Coding) standard, which is the latest video coding standard, various studies have been conducted to improve coding efficiency (for example, see Non-Patent Document 1). This method is conventionally used in H. These are the ITU-T (International Telecommunication Union Telecommunications Standardization Sector) standard indicated by H.26x, the ISO/IEC standard indicated by MPEG-x, and the H.26x standard. H.264/AVC or MPEG-4 AVC was considered as the next video encoding standard.

Patent No. 3654664

Joint Collaborative Team on Video Coding (JCT-VC) of ITU-T SG 16 WP 3 and ISO/IEC JTC 1/SC 29/WG 11 12th Meeting: Geneva, CH , 14-23 Jan. 2013 JCTVC-L1003_v34 Title: High Efficiency Video Coding (HEVC) text specification draft 10 (for FDIS & Last Call) http://phe nix. int-evry. fr/jct/doc_end_user/documents/12_Geneva/wg11/JCTVC-L1003-v34. zip "High-speed motion compensation prediction using affine transformation" by Taku Arakawa et al., Journal of the Institute of Visual Media: Visual Information Media Vol. 51, No. 7, July 20, 1997, pp. 1114-1117

In such image encoding methods and image decoding methods, it is desired to improve the encoding efficiency.

Therefore, an object of the present invention is to provide an image encoding method or an image decoding method that can improve encoding efficiency.

An image decoding device according to one aspect of the present invention includes a processing circuit and a storage device that is accessible from the processing circuit, and the processing circuit uses the storage device to apply data to a plurality of blocks included in a sequence. information that is used to determine the number of parameters used in prediction in prediction based on affine transformation is decoded from the bitstream, and for each of the plurality of blocks included in the sequence, A predicted image of each of the plurality of blocks is generated by performing prediction based on affine transformation using a number of parameters selected based on the information.

Further, an image encoding device according to an aspect of the present invention includes a processing circuit and a storage device that is accessible from the processing circuit, and the processing circuit uses the storage device to perform prediction based on affine transformation. , determine the number of parameters used for prediction, and perform prediction based on affine transformation using the determined number of parameters for each of the plurality of blocks included in the sequence. A predicted image is generated and information applied to the plurality of blocks included in the sequence and used to determine the number of parameters is encoded.

Note that these general or specific aspects may be realized by a system, a method, an integrated circuit, a computer program, or a computer-readable recording medium such as a CD-ROM (Compact Disc Read Only Memory). It may be implemented in any combination of methods, integrated circuits, computer programs, and storage media.

The present invention can provide an image encoding method or an image decoding method that can improve encoding efficiency.

FIG. 1 is a block diagram showing the configuration of an image encoding device according to the first embodiment. FIG. 2 is a flowchart showing the processing operation of the image encoding device in the first embodiment. FIG. 3 is a flowchart illustrating an example of predictive block generation processing in the first embodiment. FIG. 4 is a block diagram showing an example of a configuration of the inter prediction unit in the first embodiment. FIG. 5 is a flowchart illustrating an example of inter prediction processing in the first embodiment. FIG. 6 is a diagram for explaining motion information using a non-translation model in the first embodiment. FIG. 7 is a flowchart showing an example of a motion information transformation component selection process according to the first embodiment. FIG. 8 is a flowchart illustrating an example of conversion component selection processing using motion components in the first embodiment. FIG. 9 is a flowchart showing an example of a transform component selection process using a prediction block size according to the first embodiment. FIG. 10 is a flowchart showing an example of the residual motion information calculation process according to the first embodiment. FIG. 11 is a flowchart illustrating an example of a differential translation component calculation process in the first embodiment. FIG. 12 is a flowchart illustrating an example of differential rotation component calculation processing in the first embodiment. FIG. 13 is a flowchart illustrating an example of a process for calculating a differential expansion/contraction component in the first embodiment. FIG. 14 is a flowchart illustrating an example of differential shear component calculation processing in the first embodiment. FIG. 15 is a diagram illustrating an example of motion information in the first embodiment. FIG. 16 is a diagram illustrating an example of motion information in the first embodiment. FIG. 17 is a diagram showing an example of code levels according to the second embodiment. In FIG. FIG. 18 is a diagram illustrating an example of motion information in the second embodiment. FIG. 19 is a diagram showing an example of motion information according to the second embodiment. FIG. 20 is a block diagram showing the configuration of an image decoding device in Embodiment 4. FIG. 21 is a flowchart showing the processing operation of the image decoding device in the fourth embodiment. FIG. 22 is a flowchart illustrating an example of motion information decoding processing in the fourth embodiment. FIG. 23 is a flowchart illustrating an example of the differential motion information decoding process in the fourth embodiment. FIG. 24 is a flowchart illustrating an example of motion information generation processing in the fourth embodiment. FIG. 25 is a flowchart illustrating an example of parallel movement component generation processing in the fourth embodiment. FIG. 26 is a flowchart illustrating an example of rotational component generation processing in the fourth embodiment. FIG. 27 is a flowchart illustrating an example of the scaling component generation process in the fourth embodiment. FIG. 28 is a flowchart illustrating an example of shear component generation processing in the fourth embodiment. FIG. 29 is a diagram for explaining intra prediction processing in the fifth embodiment. FIG. 30 is a diagram for explaining intra prediction processing in the fifth embodiment. FIG. 31 is a flowchart of the image encoding method in the embodiment. FIG. 32 is a flowchart of the image decoding method in the embodiment. FIG. 33 is an overall configuration diagram of a content supply system that implements a content distribution service. FIG. 34 is a diagram showing the overall configuration of a digital broadcasting system. FIG. 35 is a block diagram showing an example of the configuration of a television. FIG. 36 is a block diagram showing an example of the configuration of an information reproducing/recording unit that reads and writes information from and to a recording medium, which is an optical disk. FIG. 37 is a diagram showing an example of the structure of a recording medium that is an optical disc. FIG. 38A is a diagram illustrating an example of a mobile phone. FIG. 38B is a block diagram showing a configuration example of a mobile phone. FIG. 39 is a diagram showing a structure of multiplexed data. FIG. 40 is a diagram schematically showing how each stream is multiplexed in multiplexed data. FIG. 41 is a diagram showing in more detail how a video stream is stored in a PES packet string. FIG. 42 is a diagram showing the structure of a TS packet and a source packet in multiplexed data. FIG. 43 is a diagram showing the data structure of PMT. FIG. 44 is a diagram showing the internal structure of multiplexed data information. FIG. 45 shows the internal structure of the stream attribute information. FIG. 46 is a diagram showing the step of identifying video data. FIG. 47 is a block diagram showing a configuration example of an integrated circuit that implements the video encoding method and video decoding method of each embodiment. FIG. 48 is a diagram showing a configuration for switching the drive frequency. FIG. 49 is a diagram showing the steps of identifying video data and switching the driving frequency. FIG. 50 is a diagram showing an example of a look-up table that associates video data standards with drive frequencies. FIG. 51A is a diagram illustrating an example of a configuration in which modules of the signal processing section are shared. FIG. 51B is a diagram showing another example of a configuration in which modules of a signal processing unit are shared.

(Knowledge that formed the basis of the invention)
In conventional image encoding systems, only information related to parallel movement is used as motion information.

However, in a captured moving image, if there is movement such as enlargement/reduction due to a zoom operation of a camera or rotation of a subject, the movement cannot be expressed appropriately only by parallel movement. Therefore, during encoding, a method is used to improve prediction accuracy by reducing the size of a prediction block.

Meanwhile, methods that use higher-level motion information such as affine transformations as motion information are also being considered. For example, in addition to translation, affine transformations can also express three types of transformations - scaling, rotation, and shearing - and can express transformations such as the rotation of the object mentioned above. This improves the quality of the generated predicted image. Also, the prediction unit can be made larger, improving coding efficiency.

However, while translation can be expressed with two-dimensional information, affine transformation requires at least six dimensions of information to express the above three types of transformation in addition to translation. This increase in the number of dimensions required for motion information causes problems such as an increase in the amount of motion information to be coded and an increase in the amount of calculations required for the motion information estimation process.

In response to this problem, the following method is disclosed in the prior art (Patent Document 1). During encoding, for each prediction block, estimation of motion information related only to translation and estimation of higher-order motion information such as affine transformation are performed. Of these, the method determined to have the highest encoding efficiency is selected. A flag indicating whether the motion information is translation or affine transformation and the motion information corresponding to that flag are encoded. This makes it possible to reduce the amount of information while taking advantage of the advantages of using high-order motion information, thereby improving encoding efficiency. However, this method has the problem that it is not possible to sufficiently reduce the amount of code when expressing high-order motion information.

To address this problem, an image encoding method according to one aspect of the present invention is an image encoding method for encoding an image, in which a translation component is used as reference information indicating a reference destination of a current block to be encoded. a selection step of selecting two or more transform components from a plurality of transform components including and a plurality of non-translation components; a prediction step of generating a predicted image using the reference information; an image encoding step of encoding using an image; a selection information encoding step of encoding selection information for specifying the two or more transform components selected from among the plurality of transform components; and a reference information encoding step of encoding the reference information of the current block using reference information of an encoded block different from the current block.

Thereby, the image encoding method can select an arbitrary transformation component from among a plurality of transformation components including a parallel movement and a plurality of non-translation movements. Therefore, the image encoding method can improve encoding efficiency in an encoding method using high-order motion information.

For example, the plurality of non-translational components may include a rotational component, a scaling component, and a shearing component.

For example, the selection information may include a flag that corresponds to each of the plurality of transformation components and indicates whether the corresponding transformation component has been selected.

Thereby, the image encoding method can divide the affine matrix into a plurality of transform components and specify selection and non-selection for each component, so that the amount of information can be reduced.

For example, in the selection step, one encoding level is selected from a plurality of encoding levels representing mutually different sets that include some or all of the plurality of transform components, and the selected encoding level is The two or more transform components included in the set represented by are selected, and the selection information may indicate the selected encoding level.

Thereby, the image encoding method can further reduce the amount of information. Moreover, the image encoding method can reduce the processing load for selection.

For example, in the selection information encoding step, one piece of selection information that is commonly used for images including the current block may be encoded.

Thereby, the image encoding method can further reduce the amount of information. Moreover, the image encoding method can reduce the processing load for selection.

For example, the selection step may select the two or more transform components according to the size of the current block, and the selection information may indicate the size.

Thereby, the image encoding method can further reduce the amount of information.

For example, the plurality of non-translational components include a rotational component, a scaling component, and a shearing component, and in the selection step, the shearing component is not selected if the size of the current block is less than a first threshold. You can.

Thereby, the image encoding method can further reduce the processing load by limiting transform components that are unlikely to contribute to improving prediction accuracy.

For example, in the selection step, the two or more transformation components may be selected in the order of the translation component, the rotation component, the scaling component, and the shear component.

As a result, the image coding method can achieve more efficient processing by increasing the priority of transformation components that contribute to improving prediction accuracy.

Further, an image decoding method according to one aspect of the present invention is an image decoding method for decoding a bitstream obtained by encoding an image, and includes a parallel component and a plurality of non-translation components. a selection information decoding step of decoding selection information for specifying two or more transform components from a plurality of transform components from the bitstream; a selection step of selecting the two or more transform components specified by the selected selection information; and using reference information of a decoded block different from the current block, the reference information of the current block is extracted from the bitstream. The method includes a reference information decoding step for decoding, a prediction step for generating a predicted image using the reference information, and an image decoding step for decoding the current block from the bitstream using the predicted image.

Thereby, the image decoding method can decode a bitstream with improved encoding efficiency.

For example, the multiple non-translation components may include four transformation components: a rotation component, a scaling component, and a shear component.

For example, the selection information may include a flag corresponding to each of the multiple transformation components and indicating whether the corresponding transformation component has been selected.

For example, the selection information indicates one of a plurality of encoding levels indicating mutually different sets that include some or all of the plurality of transform components, and in the selection step, the selection information indicates one of a plurality of encoding levels indicating mutually different sets. The two or more transform components included in the set indicated by the encoding level may be selected.

For example, in the selection information decoding step, one piece of selection information that is commonly used for images including the current block may be decoded.

For example, the selection information may indicate the size of the current block, and in the selection step, the two or more transform components may be selected according to the size of the current block.

For example, the multiple non-translation components may include a rotation component, a scaling component, and a shear component, and in the selection step, if the size of the current block is equal to or smaller than a first threshold, the shear component may not be selected.

For example, the multiple non-translation components may include a rotation component, a scaling component, and a shear component, and in the selection step, the two or more transformation components may be selected in the following order of priority: the translation component, the rotation component, the scaling component, and the shear component.

Further, an image encoding device according to one aspect of the present invention is an image encoding device that encodes an image, and includes a processing circuit and a storage device accessible from the processing circuit, and the processing circuit includes: The image encoding method is executed using the storage device.

Thereby, the image encoding device can select any transformation component from among a plurality of transformation components including a parallel shift and a plurality of non-translation components. Therefore, the image encoding device can improve encoding efficiency in an encoding method using high-order motion information.

Further, an image decoding device according to one aspect of the present invention is an image decoding device that decodes a bitstream obtained by encoding an image, and includes a processing circuit and a storage device accessible from the processing circuit. and the processing circuit executes the image decoding method using the storage device.

Thereby, the image decoding device can decode a bitstream with improved encoding efficiency.

These general or specific aspects may be realized as a system, method, integrated circuit, computer program, or computer-readable recording medium such as a CD-ROM, or may be realized as any combination of a system, method, integrated circuit, computer program, and recording medium.

Hereinafter, embodiments will be described in detail with reference to the drawings as appropriate. However, detailed explanations of well-known matters and redundant explanations of substantially the same configurations may be omitted. This is to avoid unnecessary redundancy in the following description and to facilitate understanding by those skilled in the art.

Note that all of the embodiments described below are specific examples of the present invention. The numerical values, shapes, materials, components, arrangement positions and connection forms of the components, steps, order of steps, etc. shown in the following embodiments are merely examples, and do not limit the present invention. Further, among the constituent elements in the following embodiments, constituent elements that are not described in the independent claims indicating the most significant concept will be described as arbitrary constituent elements.

(Embodiment 1)
One embodiment of an image encoding device using the image encoding method according to this embodiment will be described. The image encoding device according to the present embodiment selects an arbitrary transform component from among a plurality of transform components expressed by affine transformation, and generates a predicted image using motion information of the selected transform component. It also generates a bitstream that includes information indicating the selected transform component. Thereby, the image encoding device can improve encoding efficiency.

FIG. 1 is a block diagram of an image encoding device 100 according to this embodiment. The image encoding device 100 includes a block division unit 101, a subtraction unit 102, a frequency conversion unit 103, a quantization unit 104, an entropy encoding unit 105, an inverse quantization unit 106, an inverse frequency conversion unit 107, an addition unit 108, and intra prediction. 109, a loop filter 110, a frame memory 111, an inter prediction section 112, and a switching section 113.

The image encoding device 100 generates a bitstream 126 by encoding the input image 121.

FIG. 2 is a flowchart of the encoding process by the image encoding apparatus 100 in this embodiment.

First, the block dividing unit 101 divides an input image 121, which is a still image or a moving image including one or more pictures, into code blocks 122, which are units of encoding processing (S101).

Next, the intra prediction unit 109 or the inter prediction unit 112 generates a prediction block 134 using the decoded block 129 or decoded image 131 for each code block 122 (S102). Note that details of this processing will be described later.

Next, the subtraction unit 102 generates a difference block 123, which is the difference between the code block 122 and the prediction block 134 (S103). The frequency conversion unit 103 generates a coefficient block 124 by frequency converting the difference block 123. The quantization unit 104 generates a coefficient block 125 by quantizing the coefficient block 124 (S104).

Next, the entropy encoding unit 105 generates a bitstream 126 by entropy encoding the coefficient block 125 (S105).

On the other hand, in order to generate a decoded block 129 and a decoded image 131 that are used to generate a prediction block 134 of a subsequent block or picture, the inverse quantization unit 106 dequantizes the coefficient block 125 and decodes the coefficient block 127. generate. The inverse frequency transform unit 107 restores the difference block 128 by performing inverse frequency transform on the coefficient block 127 (S106).

Next, the adder 108 generates a decoded block 129 (reconstructed image) by adding the predicted block 134 used in step S102 and the difference block 128 (S107). This decoded block 129 is used for intra prediction processing by the intra prediction unit 109. Furthermore, the loop filter 110 generates a decoded image 131 by performing loop filter processing on the decoded block 129. The frame memory 111 stores the decoded image 131. This decoded image 131 is used for inter prediction processing by the inter prediction unit 112.

These series of processes are repeated until the encoding process for the entire input image 121 is completed (S108).

Note that the frequency conversion and quantization in step S104 and the inverse quantization and inverse frequency conversion in step S106 may be performed sequentially as separate processes, or may be performed all at once. Furthermore, quantization is a process of digitizing values sampled at predetermined intervals in association with predetermined levels. Inverse quantization is a process of returning values obtained by quantization to values in the original interval. In the field of data compression, quantization refers to the process of dividing a value into intervals that are coarser than the original, and inverse quantization refers to the process of redividing the coarse intervals into finer intervals than the original. In the codec art, quantization and inverse quantization are sometimes referred to as rounding, rounding, or scaling.

Next, the predictive block generation process in step S102 will be explained using FIG. 3. FIG. 3 is a flowchart of the predictive block generation process (S102) according to the present embodiment.

First, the image encoding device 100 determines whether the prediction processing method performed on the prediction block to be processed is intra prediction or inter prediction (S121).

When the prediction processing method is intra prediction (“intra prediction” in S121), the intra prediction unit 109 generates the prediction block 130 by intra prediction processing (S122). Further, the switching unit 113 outputs the generated prediction block 130 as a prediction block 134.

On the other hand, when the prediction processing method is inter prediction ("inter prediction" in S121), the inter prediction unit 112 generates a prediction block 132 by inter prediction processing (S123). In addition, the switching unit 113 outputs the generated prediction block 132 as a prediction block 134.

Note that the image encoding device 100 does not perform step S121, but performs both steps S122 and S123, and applies an RD optimization model (formula 1 below) or the like to each of the obtained prediction blocks. It is also possible to perform cost calculation using , and select a method with a low cost, that is, a method with high encoding efficiency.

In (Formula 1), D represents encoding distortion, and is, for example, the sum of absolute differences between the original pixel value of the block to be encoded and the generated predicted image. Further, R represents the amount of generated code, and is, for example, the amount of code necessary to encode motion information for generating a prediction block. Further, λ is a Lagrangian undetermined multiplier. Thereby, it becomes possible to select an appropriate prediction mode from intra prediction and inter prediction, and it is possible to improve encoding efficiency.

Next, the inter prediction process in step S123 will be explained using FIGS. 4 and 5.

FIG. 4 is a block diagram showing a configuration example of the inter prediction unit 112. The inter prediction unit 112 includes a coded information selection unit 141, a motion estimation unit 142, a motion compensation unit 143, and a motion information calculation unit 144.

FIG. 5 is a flowchart of the inter prediction process (S123) according to the present embodiment.

First, the encoded information selection unit 141 selects a transformation component (deformation component) of motion information to be used, using the input image (code block 122) or the like (S141). Here, the transformation component is information indicating various transformations (transformations) (for example, parallel movement, rotation, scaling, and shearing), and is a coefficient etc. in various transformations. As shown in FIG. 6, in this embodiment, in addition to parallel movement, a plurality of non-parallel movements such as rotation, scaling, and shearing are used for the motion information.

Next, the motion estimation unit 142 generates motion information 151 by performing motion estimation processing regarding the transformation component of the motion information selected in step S141 using the input image (code block 122) and the decoded image 131 (S142 ).

Next, the motion compensation unit 143 generates a prediction block 132 by performing motion compensation processing using the motion information 151 and decoded image 131 obtained in step S142 (S143).

Next, the motion information calculation unit 144 calculates differential motion information, which is the difference between the motion information 151 obtained in step S142 and the motion information of an encoded block that is spatially or temporally adjacent to the current block to be encoded (S144).

With the above steps, the inter prediction process ends. Note that the differential motion information calculated in step S144 is output to the entropy encoding unit 105 as motion information 133. Entropy encoding section 105 encodes motion information 133, includes it in bitstream 126, and outputs it.

Next, the selection of motion information conversion components (S141) will be explained in detail using FIG. 7. FIG. 7 is a flowchart of selection of motion information conversion components (S141) according to the present embodiment.

First, the encoded information selection unit 141 obtains a motion component between the input image (code block 122) and the decoded image 131 (S161). For example, the encoded information selection unit 141 extracts SIFT (Scale-Invariant Feature Transform) features of both the input image and the decoded image 131. The encoded information selection unit 141 estimates a homography matrix expressing various transformations from the feature amount of the input image and the feature amount of the decoded image 131, and sets it as a motion component between images. Note that although an example is shown here in which a SIFT feature quantity is used as a feature quantity set as a motion component, the present invention is not limited to this.

Next, the encoded information selection unit 141 selects a transformed component of motion information to be used for encoding, according to the motion component acquired in step S161 (S162). Further, the encoding information selection unit 141 selects a transformation component of motion information to be used for encoding according to the size of the prediction block (S163). Through the above series of processes, the process of step S141 is completed.

Note that step S162 and step S163 may both be performed in this order, may be performed in the reverse order, may be performed in parallel, or only one of them may be performed. good.

In this embodiment, "motion component" indicates a feature amount (movement between images) obtained by analyzing an image using a predetermined analysis method, and "motion information" indicates a feature amount (movement between images) obtained by analyzing an image using a predetermined analysis method. It will be explained as indicating the matrices, vectors, or coefficients constituting them, which are determined by the method used for encoding.

Details will be described below regarding the selection of transform components using motion components (step S162) and the selection of transform components using the size of the prediction block (step S163).

FIG. 8 is a flowchart of selection of transformation components using motion components (step S162) according to the present embodiment.

First, the encoded information selection unit 141 extracts translation components such as translation, rotation, scaling, and shearing from the motion components (S181).

Here, the affine matrix a can be expressed as shown below (Equation 2). As shown in the following (Equation 2), the affine matrix a is a matrix representing the expansion/reduction of the expansion rate k (k _x in the x direction, k _y in the y direction), a matrix representing the rotation by the rotation angle θ, and a shear angle It is expressed as the sum of the product of matrices each representing the shear of φ and the matrix representing translation by c in the x direction and f in the y direction.

From the affine matrix a expressed as in the above (Equation 2), it is possible to extract the magnification factor k, rotation angle θ, shear angle φ, and translation component. The motion information is described as information having the above four transformation components, and is expressed as (c, f, θ, k _x , k _y , φ), for example.

If the translation components c and f are both 0, the motion information does not contain a translation component, otherwise it contains a translation component. If the magnification ratio k is 1, the motion information does not contain a scaling component, otherwise it contains a scaling component. If the rotation angle θ is 0, the motion information does not contain a rotation component, otherwise it contains a rotation component. If the shear angle φ is 0, the motion information does not contain a shear component, otherwise it contains a shear component.

Note that here, an example is shown in which the threshold values of the respective transformation components of parallel translation, rotation, scaling, and shearing are (0, 0), 0, (1, 1), and 0, but the present invention is not limited to this. isn't it. These threshold values may be values that take into consideration the characteristics of the image or the accuracy of the imaging device. Furthermore, the same magnification factor may be used in the x direction and the y direction without dividing the scaling into the x direction and the y direction. Thereby, the amount of code and processing amount can be reduced.

In this way, in step S181, the encoded information selection unit 141 extracts various transformation components from the motion information. Note that although the case where motion information is expressed using an affine matrix has been described here, the motion information that can be used is not limited to this. In the following description, it is assumed that the rotation angle represents a rotation component, the magnification ratio represents a scaling component, the shear angle represents a shear component, and the translation vector represents translation.

Subsequently, the encoded information selection unit 141 performs selection processing to determine whether or not to use parallel movement. First, in step S181, the encoded information selection unit 141 determines whether a parallel component indicated by a motion vector or the like has been extracted from the motion component (S182).

If a translation component exists in the motion component (Yes in S182), the encoded information selection unit 141 selects translation (S183). On the other hand, if there is no parallel movement component in the motion components (No in S182), the encoded information selection unit 141 does not select parallel movement (S184).

Next, the encoded information selection unit 141 determines whether or not to use rotation. In step S181, the encoded information selection unit 141 determines whether the rotation component indicated by the rotation angle θ or the like has been extracted from the motion component (S185).

If a rotation component exists in the motion component (Yes in S185), the encoded information selection unit 141 selects rotation (S186). If there is no rotation component in the motion component (No in S185), the encoded information selection unit 141 does not select rotation (S187).

Next, the encoded information selection unit 141 determines whether to use scaling. In step S181, the encoded information selection unit 141 determines whether the enlargement/reduction component indicated by the enlargement rate k or the like has been extracted from the motion component (S188). If a scaling component exists in the motion component (S188: Yes), the encoded information selection unit 141 selects scaling (S189). If there is no scaling component in the motion component (No in S188), the encoded information selection unit 141 does not select scaling (S190).

Finally, the encoded information selection unit 141 determines whether or not to use shearing. In step S181, the encoded information selection unit 141 determines whether a shear component indicated by a shear angle φ or the like has been extracted from the motion component (S191).

If a shear component exists in the motion component (Yes in S191), the encoded information selection unit 141 selects shear (S192). If a shear component does not exist in the motion component (No in S191), the encoded information selection unit 141 does not select shear (S193). The above series of processes completes the process of step S162.

Next, step S163 shown in FIG. 7 will be explained using FIG. 9. FIG. 9 is a flowchart of selection of transform components using block size (step S163) according to the present embodiment.

First, the encoding information selection unit 141 acquires the block size of a prediction block (S201).

First, the encoded information selection unit 141 determines whether to use parallel movement. The encoded information selection unit 141 determines whether the block size acquired in step S201 is 4×4 blocks or less (S202).

If the block size is larger than 4×4 blocks (No in S202), the encoded information selection unit 141 selects parallel movement (S203). On the other hand, if the block size is 4×4 blocks or less (Yes in S202), the encoded information selection unit 141 does not select parallel movement (S204).

Next, the encoded information selection unit 141 determines whether or not to use rotation. The encoded information selection unit 141 determines whether the block size acquired in step S201 is 8×8 blocks or less (S205).

If the block size is larger than 8×8 blocks (No in S205), the encoded information selection unit 141 selects rotation (S206). On the other hand, if the block size is 8×8 blocks or less (Yes in S205), the encoded information selection unit 141 does not select rotation (S207).

Next, the encoded information selection unit 141 determines whether to use scaling. The encoded information selection unit 141 determines whether the block size acquired in step S201 is 16×16 blocks or less (S208). If the block size is larger than 16×16 blocks (No in S208), the encoded information selection unit 141 selects scaling (S209). On the other hand, if the block size is 16×16 blocks or less (Yes in S208), the encoded information selection unit 141 does not select scaling (S210).

Finally, the encoded information selection unit 141 determines whether or not to use shearing. The encoded information selection unit 141 determines whether the block size acquired in step S201 is 32×32 blocks or less (S211).

If the block size is larger than 32×32 blocks (No in S211), the encoded information selection unit 141 selects shearing (S212). On the other hand, if the block size is 32×32 blocks or less (Yes in S211), the encoded information selection unit 141 does not select shearing (S213). After the series of processes described above, the process of step S163 ends.

Here, in steps S202, S205, S208, and S211, a case has been described in which 4×4, 8×8, 16×16, and 32×32 are used as examples of block size thresholds, respectively, but the block size thresholds are as follows: It is not limited to this and may be any size. Further, the encoded information selection unit 141 may switch the threshold value according to the characteristics of the image. Thereby, encoding efficiency can be improved.

Further, here, an example has been described in which step S162 and step S163 are performed sequentially in this order, but the order may be reversed, or some or all of these processes may be performed simultaneously. Further, only one of step S162 and step S163 may be performed.

When both step S162 and step S163 are performed, for example, the encoding information selection unit 141 selects the transformation when a transformation component exists and the block size is larger than the threshold, and otherwise selects the transformation. , do not select the conversion. In other words, the encoded information selection unit 141 selects the transformation determined to be selected in both step S162 and step S163, and does not select the transformation determined not to be selected in at least one of step S162 and step S163.

Alternatively, the encoded information selection unit 141 may first perform the size comparison in step S163 and determine whether or not there is a transform component (S162) only for the transform determined to be selected. Alternatively, the encoded information selection unit 141 may first determine the presence or absence of a transform component in step S162, and then compare block sizes (S163) only for transforms in which a transform component exists.

Furthermore, the order of steps S182 to S193 shown in FIG. 8 may be arbitrary, and some or all of them may be performed in parallel. Similarly, the order of S202 to S213 shown in FIG. 9 may be arbitrary, and some or all of them may be performed in parallel.

However, the inventors' verification revealed that the shear component has fewer valid images than the other transform components, and therefore is less likely to contribute to improving prediction accuracy. Therefore, the priority of the shear component may be set lower than that of the other transform components. For example, the priority can be lowered by placing the determination process after the determination process of the other components, or by setting the block size threshold larger than the threshold of the other components.

In step S142 following step S141 shown in FIG. 5, the motion estimation unit 142 performs motion estimation regarding the transformed component selected in step S141. For example, the motion estimating unit 142 calculates a residual signal (difference block) while changing each of a plurality of transform components, such as the magnitude of translation and the magnification rate, by a constant value. Then, the motion estimation unit 142 determines, as the motion information 151, a combination of transform components corresponding to the smallest residual signal among the plurality of obtained residual signals.

Next, in step S143, the motion compensation unit 143 generates a predicted image (predicted block 132) from the decoded image 131 using the motion information 151 obtained in step S142.

Regarding the final step S144, details will be described using FIGS. 10 to 14.

FIG. 10 is a flowchart of the differential motion information calculation process (S144) according to the present embodiment.

First, the motion information calculation unit 144 derives predictive motion information from motion information used in one or more encoded blocks spatially or temporally adjacent to the current block to be encoded (S221). Note that the predictive motion information includes a translation component, a rotation component, a scaling component, and a shear component, just like the motion information. Note that, hereinafter, the various transformation components included in the predictive motion information are also referred to as predicted transformation components. Also, the translation component, rotation component, scaling component, and shear component included in the predictive motion information are also referred to as predicted translation component, predicted rotation component, predicted scaling component, and predicted shear component.

For example, the motion information calculation unit 144 obtains a plurality of transform components of the type included in the plurality of motion information of the plurality of coded blocks for each type of predictive transform component, and from the plurality of obtained transform components. A predicted transformation component of the relevant type is derived. For example, the motion information calculation unit 144 derives the average value of the transform components of each of a plurality of coded blocks that refer to the same reference picture as the predicted transform component. Note that as a method for deriving the predicted transformation component, all other calculation methods such as those used in HEVC etc. can be applied.

First, the motion information calculation unit 144 calculates a differential translation component, which is differential motion information of the parallel component (S222).

Figure 11 is a flowchart of the process of calculating this differential translation component (S222).

First, the motion information calculation unit 144 determines whether a parallel movement component exists in the motion information 151 estimated in step S142 (S241). For example, if the x-direction and y-direction components included in the translational component are both zero, the motion information calculation unit 144 determines that the translational component does not exist, and at least one of the x-direction and y-direction components. is not zero, it is determined that a parallel component exists. Note that the motion information calculation unit 144 may determine that there is no parallel movement component when the magnitude of the parallel movement component is smaller than a certain predetermined value. Furthermore, the motion information calculation unit 144 may switch the predetermined value depending on the characteristics of the image. Further, the motion information calculation unit 144 may determine that a translational component always exists (or a translational component does not always exist) when the features of the image satisfy a predetermined condition.

Further, the motion information calculation unit 144 may determine that there is no parallel movement component when it is determined in step S184 of FIG. 8 or step S204 of FIG. 9 that parallel movement is not selected.

If there is no parallel movement component in the motion information 151 (No in S241), the motion information calculation unit 144 sets the parallel movement flag indicating that “parallel movement exists” to OFF, and sets the parallel movement flag to OFF. It is added to the motion information 133 to be converted (S242).

If a parallel movement component exists in the motion information 151 (Yes in S241), the motion information calculation unit 144 sets the parallel movement flag to ON, and adds the parallel movement flag to the movement information 133 (S243).

Next, the motion information calculation unit 144 determines whether a parallel movement component exists in the predicted motion information derived in step S221 (S244). If the predicted motion information does not include a translational component (No in S244), the motion information calculation unit 144 sets the predicted translational component to 0 (S245).

On the other hand, if the predicted motion information includes a translational component (Yes in S244), the motion information calculation unit 144 sets the translational component of the predicted motion information as the predicted translational component (S246).

Next, the motion information calculation unit 144 calculates a differential translation component by subtracting the predicted translation component obtained in step S245 or S246 from the translation component of the motion information 151 obtained in step S142, The calculated differential translation component is added to the motion information 133 (S247).

Subsequently, the motion information calculation unit 144 calculates a differential translation component, which is differential motion information of the rotational component (S223).

FIG. 12 is a flowchart of this differential rotation component calculation process (S223).

First, the motion information calculation unit 144 determines whether a rotation component exists in the motion information 151 estimated in step S142 (S261). For example, the motion information calculation unit 144 may determine whether the rotation component is zero, similar to the determination of parallel movement (S241), or may compare the magnitude of the rotation angle with a certain predetermined value. . Furthermore, the motion information calculation unit 144 may switch the predetermined value depending on the characteristics of the image. For example, the motion information calculation unit 144 always determines that a rotational component exists if the image has a feature that rotation is likely to contribute to improving prediction accuracy, and otherwise determines that a rotational component does not exist. You may. If it is determined that the rotation angle always exists, for example, the rotation angle θ is determined in advance based on the time conversion of the angle from the rotation center, and the motion information calculation unit 144 may always use that value.

Further, the motion information calculation unit 144 may determine that there is no rotation component when it is determined in step S187 of FIG. 8 or step S207 of FIG. 9 that rotation is not selected.

If there is no rotation component in the motion information 151 (No in S261), the motion information calculation unit 144 sets the rotation flag indicating that "rotation exists" to OFF, and uses the rotation flag as the motion to be encoded. It is added to the information 133 (S262).

If a rotation component exists in the motion information 151 (Yes in S261), the motion information calculation unit 144 sets the rotation flag to ON and adds the rotation flag to the motion information 133 (S263).

Next, the motion information calculation unit 144 determines whether a rotation component exists in the predicted motion information acquired in step S221 (S264).

If the predicted motion information does not include a rotational component (No in S264), the motion information calculation unit 144 sets the predicted rotational component to 0 (S265). If the predicted motion information includes a rotational component (Yes in S264), the motion information calculation unit 144 sets the rotational component of the predicted motion information as the predicted rotational component (S266).

The motion information calculation unit 144 calculates a differential rotation component by subtracting the predicted rotation component obtained in step S265 or S266 from the rotation component of the motion information obtained in step S142, and adds the calculated differential rotation component to the motion information 133 (S267).

Next, the motion information calculation unit 144 calculates a differential scaling component that is differential motion information of the scaling component (S224).

FIG. 13 is a flowchart of this differential expansion/contraction component calculation process (S224).

First, the motion information calculation unit 144 determines whether a scaling component exists in the motion information 151 estimated in step S142 (S281). For example, the motion information calculation unit 144 may determine whether the scaling component is zero (the value is 1) as in step S241 or S261, or may compare the magnitude of the scaling component with a certain predetermined value. You may. Furthermore, the motion information calculation unit 144 may switch the predetermined value depending on the characteristics of the image. For example, the motion information calculation unit 144 may set a predetermined value based on a change in the angle of view over time in the case of a zoomed-in or zoomed-out video.

Further, the motion information calculation unit 144 determines that a scaling component always exists if the scaling component has a feature that is likely to greatly contribute to prediction accuracy, and if this is not the case, the scaling component always exists. You may decide not to do so. For example, the motion information calculation unit 144 may determine that an enlargement/reduction component always exists when the input image 121 is a video obtained by zooming in or zooming out. If it is determined that it always exists, for example, the value of the scaling component is determined in advance based on the temporal change in the angle of view, and the motion information calculation unit 144 may always use that value.

Further, the motion information calculation unit 144 may determine that there is no scaling component when it is determined in step S190 of FIG. 8 or step S210 of FIG. 9 that scaling is not selected.

If there is no scaling component in the motion information 151 (No in S281), the motion information calculation unit 144 sets the scaling flag indicating that "scaling exists" to OFF, and sets the scaling flag to OFF. It is added to the motion information 133 to be converted (S282).

If a scaling component exists in the motion information 151 (Yes in S281), the motion information calculation unit 144 sets the scaling flag to ON and adds the scaling flag to the motion information 133 (S283).

Next, the motion information calculation unit 144 determines whether the predicted motion information obtained in step S221 contains a scaling component (S284).

If there is no scaling component in the predicted motion information (No in S284), the motion information calculation unit 144 sets the predicted scaling component to 1 (S285). If a scaling component exists in the predicted motion information (Yes in S284), the motion information calculation unit 144 sets the scaling component of the predicted motion information as a predicted scaling component (S286).

The motion information calculation unit 144 calculates a difference scaling component by subtracting the predicted scaling component obtained in step S284 or S285 from the scaling component of the motion information obtained in step S142, and calculates the difference scaling component. The scaling component is added to the motion information 133 (S287).

Finally, the motion information calculation unit 144 calculates a differential shear component, which is differential motion information of the shear component (S225).

Figure 14 is a flowchart of the process for calculating this differential shear component (S225).

First, the motion information calculation unit 144 determines whether a shear component exists in the motion information 151 estimated in step S142 (S301). For example, the motion information calculation unit 144 may determine whether the shear component is zero, as in step S241, S261, or S281, or may compare the magnitude of the shear component with a certain predetermined value. . Furthermore, the motion information calculation unit 144 may switch the predetermined value depending on the characteristics of the image. Further, the motion information calculation unit 144 may determine that a shear component is always present (or a shear component is not always present) when the image feature satisfies a predetermined condition.

Further, the motion information calculation unit 144 may determine that there is no shear component when it is determined in step S193 of FIG. 8 or step S213 of FIG. 9 that shear is not selected.

If a shear component does not exist in the motion information 151 (No in S301), the motion information calculation unit 144 sets the shear flag indicating that "shear exists" to OFF, and sets the shear flag to OFF as the motion information to be encoded. It is added to the information 133 (S302).

If a shear component is present in the motion information 151 (Yes in S301), the motion information calculation unit 144 sets the shear flag to on and assigns the shear flag to the motion information 133 (S303).

Next, the motion information calculation unit 144 determines whether a shear component exists in the predicted motion information acquired in step S221 (S304).

If the predicted motion information does not include a shear component (No in S304), the motion information calculation unit 144 sets the predicted shear component to 0 (S305). If the predicted motion information includes a shear component (Yes in S304), the motion information calculation unit 144 sets the shear component of the predicted motion information as the predicted shear component (S306).

The motion information calculation unit 144 calculates a differential shear component by subtracting the predicted shear component obtained in step S305 or S306 from the shear component of the motion information obtained in step S142, and calculates the calculated differential shear component. It is added to the motion information 133 (S307).

After the above processing, the processing in step S144 ends.

Note that the processing order of steps S222 to S225 is not limited to this order, but may be any order. Further, some or all of these processes may be performed in parallel. Furthermore, as described above, if the transform components that can be used for encoding are restricted due to the size of the current block, etc., the motion information calculation unit 144 processes only the allowed transform components. You can.

15 and 16 are diagrams showing examples of motion information 133 to be encoded. As shown in FIG. 15, the motion information 133 includes a parallel movement flag 161, a rotation flag 162, an enlargement/reduction flag 163, a shear flag 164, a differential translation component 171, a differential rotation component 172, and a differential enlargement/reduction. It includes a component 173 and a differential shear component 174. Note that the meaning of each piece of information is as described above.

Further, only when each flag is on, the motion information 133 includes a differential motion component corresponding to the flag. For example, as shown in FIG. 16, when the parallel movement flag 161 and the rotation flag 162 are ON, and the scaling flag 163 and the shear flag 164 are OFF, the motion information 133 includes the differential translation component 171 and the differential rotation component. Component 172 is included, and differential scaling component 173 and differential shear component 174 are not included.

(effect)
As described above, the image encoding apparatus 100 according to the present embodiment selects only necessary transformation components using the characteristics of the image, and information (translation flag, rotation flag, enlargement flag, etc.) indicating the selected transformation components. (reduction flag and shear flag) and the selected transform components. Thereby, the image encoding device 100 can selectively use only effective transform components, thereby improving encoding efficiency. In this way, the image encoding device 100 can flexibly select various types of conversion and reduce the amount of motion information required to generate a predicted image, thereby improving encoding efficiency.

Further, the image encoding device 100 selects a transform component using the estimation result of the type of transform existing in the image being encoded, the size of a prediction block, or the like. Thereby, the image encoding device 100 can limit the types of motion information to be searched during prediction processing, and thus can speed up the processing.

Note that in this embodiment, affine transformation is used as motion information, and translation, rotation, scaling, and shearing are used as types of transformation, but the types of transformation used are not limited to these.

For example, instead of an affine matrix, a projective transformation matrix that can express projective transformation may be used. In this case, trapezoidal transformation can be used as motion information. As a result, it is possible to further improve the quality of the prediction block and to expect an improvement in encoding efficiency.

That is, the image encoding device 100 according to the present embodiment only needs to be able to divide a motion component into a plurality of transform components and determine whether each transform component is used. That is, the image encoding device 100 may use matrices or transformations other than those described above, or may divide motion information into transformation components different from those described above.

In addition, in the above description, an example was shown in which flags are assigned to each transform component on a block-by-block basis during inter prediction in steps S242, S243, S261, S263, S282, S283, S302, and S303. may be specified in image units, sequence units, or area units into which an image is divided. For example, this area is an area where the image is divided into four. As a result, before performing inter prediction, all blocks included in a prespecified image or sequence are encoded using the same type of transform component. Therefore, since the determination process for each block can be omitted, the encoding efficiency can be further improved. Furthermore, since the number of flags in the bitstream can be reduced, encoding efficiency can be further improved.

In addition, in the case where the predicted motion information does not include various transformation components, 0, 0, 1, and 0 are respectively substituted as the predicted transformation components in steps S245, S265, S285, and S305, but the values substituted are not limited to these. For example, when the entire screen is rotated, an angle determined according to the characteristics of the image may be substituted as the predicted rotation component. Furthermore, a process of substituting a predetermined angle such as 0 for the predicted transformation component and a process of substituting an angle determined according to the characteristics of the image for the predicted transformation component may be switched according to a predetermined condition. In this way, when a transformation component exists in the motion information but does not exist in the predicted motion information, it is possible to reduce the value of the differential motion information by performing prediction while switching the substituted value. This can further improve the coding efficiency.

(Embodiment 2)
In the first embodiment, an example is described in which flags corresponding to each of a plurality of conversions are used as information indicating whether each of the various conversions is used. In this embodiment, ranks (encoding levels) are associated with combinations of various transform components. Information specifying this encoding level is used as the above information.

In this embodiment, instead of the above-described steps S162 and S163, the following process is performed, for example.

FIG. 17 is a diagram illustrating an example of the relationship between code levels and transform components. As shown in FIG. 17, for example, encoding level 1 includes translation, encoding level 2 includes rotation and scaling, and encoding level 3 includes shearing.

The encoding information selection unit 141 selects the encoding level depending on conditions such as image characteristics or allowable bandwidth.

Next, the encoded information selection unit 141 selects transform components included in encoding levels lower than or equal to the selected encoding level. For example, in the case of encoding level 2, three types of transformation components included in encoding level 2 and encoding level 1 are selected: translation, rotation, and scaling.

In addition, encoding level information 181 indicating the selected encoding level is added to the motion information 133 to be encoded.

FIGS. 18 and 19 are diagrams showing examples of motion information 133 to be encoded. As shown in FIG. 18, the motion information 133 includes encoding level information 181, a differential translation component 171, a differential rotation component 172, a differential scaling component 173, and a differential shearing component 174.

Further, the motion information 133 includes a differential motion component corresponding to a transform component included in a coding level lower than or equal to the coding level indicated by the coding level information 181. For example, as shown in FIG. 19, when the encoding level information 181 indicates encoding level 2, the motion information 133 includes a differential translation component 171, a differential rotation component 172, and a differential scaling component of encoding levels 1 and 2. 173 and does not include the differential shear component 174 of encoding level 3.

As described above, in this embodiment, the amount of information required for encoding can be further reduced, so that encoding efficiency can be improved. Note that, although an example using various transformation levels has been described here, this is not limited thereto, and information indicating a combination of transformation components may be used. For example, in the above, an example in which all transformation components included in the selected level or lower are specified has been described, but the following information may be used. For example, at level 0, all transformation components are not used, at level 1, only translation is used, at level 2, translation and rotation are used, at level 3, translation and scaling are used, at level 4, rotation and scaling are used, at level 5, translation, rotation and scaling are used, at level 6, translation and shear are used, and at level 7, translation, rotation, scaling and shear may be used. In this way, a combination of transformation components may be specified for each level, and a transformation component associated with each level may be selected.

(Embodiment 3)
The inventors verified that among translation, rotation, scaling, and shearing, shearing is less likely to contribute to improving prediction accuracy than other transformations. Therefore, in this embodiment, an example in which priorities are assigned to a plurality of transformation components will be described.

As a first method of prioritizing a plurality of transform components, the block size threshold is changed as in the process of step S163 shown in FIG. 9 described above. Specifically, the shear threshold is set larger than other transformations, such as rotation, which can greatly improve prediction accuracy. As a result, when the block size is small, it is possible to restrict the use of transform components that are difficult to improve prediction accuracy, so it is possible to suppress a decrease in encoding efficiency. Similarly, since scaling does not contribute much to improving prediction accuracy with small block sizes, a larger threshold is set than for parallel translation and rotation.

When the inventors tested common moving images, they found that the order of translation, rotation, scaling, and shearing is most likely to improve prediction accuracy, although the ranking varies depending on the characteristics of the image. Therefore, the priorities are set in this order. This makes it possible to restrict the selection of low-priority transform components depending on the image characteristics, size, band, and other conditions.

A second method of prioritizing a plurality of transform components will be described below. Here, an example of a method for limiting shearing will be described.

First, we will briefly explain how to set coefficients for affine transformation. As described in Non-Patent Document 2, by setting the evaluation function E(a) with the affine matrix a as a variable shown in the following (Equation 3) and solving the minimization problem, the coefficients of the affine matrix can be calculated. Set. That is, the coefficient (motion information) for which the evaluation function E(a) is the smallest is derived.

If the shear is limited, the orthogonality of the axes in the x and y directions is maintained before and after the affine transformation. In other words, the coefficients of the affine transformation shown in the above (Formula 2) need to satisfy the constraint condition of the following (Formula 4).

Therefore, a constraint condition is added to the evaluation function of (Formula 3) above as shown in (Formula 5) below. Due to this constraint, the larger the shear component, the larger the value of the evaluation function E(a) becomes, making it difficult to select a coefficient that includes a shear component. This method is called the penalty method. Furthermore, by increasing the positive constant μ, the influence of the constraint condition becomes greater. In this way, by determining the coefficients of the affine matrix that minimize the evaluation function E(a) in (Equation 5) below, it becomes possible to calculate coefficients with limited shear components.

The inventors set a small μ, solved the minimization problem, repeated the search a certain number of times, set the optimal solution at that point as the new initial value, and ran the minimization problem again with a larger value of μ. The coefficients were calculated by repeating the solving process until μ reached a predetermined size. Note that the method for determining the coefficients is not limited to this method.

Also, while we've explained how to limit shear (lower priority), similar techniques can be applied to other transformations.

(Other variations)
In the first to third embodiments described above, a method of encoding differential motion information, which is the difference between motion information and predicted motion information, has been described, but the present invention is not limited to this.

For example, in HEVC, there is a motion prediction method called merge mode. In this merge mode, difference information is not encoded, and a motion vector predictor selected from a plurality of motion vector predictor candidates is used as the motion vector of the current block. Then, selection information indicating the selected motion vector predictor candidate is encoded. In such a case, as in the first to third embodiments described above, the image encoding device selects one or more transform components from a plurality of transform components, and generates a predicted image using the selected transform components. You can. Further, the image encoding device may encode information (the above-mentioned flag or encoding level information) indicating the selected (used) transform component.

For example, the image coding device codes the selected transformation component based on whether or not various transformation components are present in prediction information predicted from motion information of blocks spatially or temporally adjacent to the current block. In this case, if the motion information of the adjacent blocks all contain a rotation component, the image coding device may use the average value of the rotation components as the rotation component of the current block. Also, if only one of the motion information of the adjacent blocks contains a rotation component and the rotation component is less than a predetermined value, the image coding device may decide not to use a rotation component for the current block. Alternatively, the image coding device may set the rotation components of the other adjacent blocks to zero, calculate the average value of the multiple rotation components, and use the calculated average value as the rotation component.

A method using such an average value, a method using temporal scaling processing, and the like are known, and these modifications may be applied to this embodiment.

(Embodiment 4)
In this embodiment, one embodiment of an image decoding apparatus that decodes a bitstream generated by the image encoding apparatus according to Embodiment 1 will be described.

FIG. 20 is a block diagram of image decoding device 200 according to this embodiment. The image decoding device 200 includes an entropy decoding section 201, an inverse quantization section 202, an inverse frequency transformation section 203, an addition section 204, an intra prediction section 205, a loop filter 206, a frame memory 207, an inter prediction section 208, and a switching section 209. include.

The image decoding device 200 generates a decoded image 227 by decoding the bitstream 221. For example, the bitstream 221 is generated by the image encoding device 100 described above.

FIG. 21 is a flowchart of image decoding processing according to this embodiment.

First, the entropy decoding unit 201 decodes motion information 228 from a bitstream 221 obtained by encoding a still image or a moving image including one or more pictures (S401). Furthermore, the entropy decoding unit 201 decodes the coefficient block 222 from the bitstream 221 (S402).

The dequantization unit 202 generates a coefficient block 223 by dequantizing the coefficient block 222. The inverse frequency transform unit 203 restores the difference block 224 by performing inverse frequency transform on the coefficient block 223 (S403).

Next, the intra prediction unit 205 or the inter prediction unit 208 generates a prediction block 230 using the motion information 228 decoded in step S401 and the decoded block that has already been decoded (S404). Specifically, the intra prediction unit 205 generates a prediction block 226 by an intra prediction process. The inter prediction unit 208 generates a prediction block 229 by an inter prediction process. The switching unit 209 outputs one of the prediction blocks 226 and 229 as the prediction block 230.

Next, the adding unit 204 generates a decoded block 225 by adding the difference block 224 and the prediction block 230 (S405). This decoding block 225 is used for intra prediction processing by the intra prediction unit 205.

Next, the image decoding device 200 determines whether all blocks included in the bit stream 221 have been decoded (S406). For example, the image decoding device 200 makes this determination depending on whether the input bit stream 221 has been completed. If the decoding of all blocks has not been completed (No in S406), the processing from step S401 onwards is performed on the next block. If the decoding of all blocks included in the bit stream 221 has been completed (Yes in S406), the loop filter 206 generates a decoded image 227 (reconstructed image) by combining all the decoded blocks and performing loop filter processing (S407). The frame memory 207 stores the decoded image 227. This decoded image 227 is used for inter prediction processing by the inter prediction unit 208.

Note that the inverse quantization and inverse frequency conversion in step S403 may be performed sequentially as separate processes, or may be performed all at once. Note that in currently mainstream coding standards such as HEVC, inverse quantization and inverse frequency conversion are performed at once. Also, on the decoding side, similar to the encoding side (Embodiment 1), expressions such as scaling may be used.

Next, the motion information decoding process (S401) will be described with reference to FIG. 22. FIG. 22 is a flowchart of the motion information decoding process (S401) according to this embodiment.

First, the entropy decoding unit 201 decodes differential motion information from the bitstream 221 (S421). Furthermore, the entropy decoding unit 201 decodes information for deriving predicted motion information (S422). Note that information for deriving predicted motion information and differential motion information are included in the motion information 228. Next, the inter prediction unit 208 derives predicted motion information from the information acquired in step S422, and generates motion information from the derived predicted motion information and the differential motion information acquired in step S421 (S423 ).

Details regarding differential motion information decoding (S421) and motion information generation (S423) will be described below.

The decoding process (S421) of differential motion information will be explained using FIG. 23. FIG. 23 is a flowchart of the differential motion information decoding process (S421) according to this embodiment.

First, the entropy decoding unit 201 performs decoding processing of the differential translation component (S441 to S443). First, the entropy decoding unit 201 decodes a parallel movement flag indicating whether a parallel movement exists (indicating whether a differential translation component is included in the motion information 228) from the bitstream 221 (S441). Note that the configuration of the motion information 228 and the meanings of the various information included in the motion information 228 are the same as the configuration of the motion information 133 and the meanings of the various information included in the motion information 133 in the first embodiment. Next, the entropy decoding unit 201 determines whether parallel movement exists using the parallel movement flag (S442).

If the parallel movement flag indicates that there is a parallel movement (Yes in S442), the entropy decoding unit 201 decodes the differential translation component from the bitstream 221 (S443). If the parallel movement flag indicates that there is no parallel movement (No in S442), the entropy decoding unit 201 performs the next processing step (S444) without decoding the differential translation component.

Subsequently, the entropy decoding unit 201 performs decoding processing of the differential rotation component (S444 to S446). The entropy decoding unit 201 decodes a rotation flag indicating whether rotation exists (indicating whether a differential rotation component is included in the motion information 228) from the bitstream 221 (S444). The entropy decoding unit 201 uses the rotation flag to determine whether rotation exists (S445).

If the rotation flag indicates that rotation exists (Yes in S445), the entropy decoding unit 201 decodes the differential rotation component from the bitstream 221 (S446). If the rotation flag indicates that there is no rotation (No in S445), the entropy decoding unit 201 performs the next processing step (S447).

Next, the entropy decoding unit 201 performs decoding processing of the differential scaling component (S447 to S449). The entropy decoding unit 201 decodes a scaling flag indicating whether scaling exists (indicating whether a differential scaling component is included in the motion information 228) from the bitstream 221 (S447). The entropy decoding unit 201 uses the scaling flag to determine whether scaling exists (S448).

If the scaling flag indicates that scaling exists (Yes in S448), the entropy decoding unit 201 decodes the differential scaling component from the bitstream 221 (S449). If the scaling flag indicates that there is no scaling (No in S448), the entropy decoding unit 201 performs the next processing step (S450).

Finally, the entropy decoding unit 201 performs a decoding process of the differential shear component (S450 to S452). The entropy decoding unit 201 decodes a shear flag indicating whether a shear component is present (indicating whether the motion information 228 includes a differential shear component) from the bit stream 221 (S450). The entropy decoding unit 201 uses the shear flag to determine whether a shear component is present (S451).

If the shear flag indicates that shear exists (Yes in S451), the entropy decoding unit 201 decodes the differential shear component from the bitstream 221 (S452). After that, the entropy decoding unit 201 ends the differential motion information decoding process (S421). If the shear flag indicates that there is no rotation (No in S451), the entropy decoding unit 201 ends the differential motion information decoding process (S421).

Next, the motion information generation process (S423) will be explained using FIGS. 24 to 28.

FIG. 24 is a flowchart of the motion information generation process (S423) according to this embodiment.

First, the inter prediction unit 208 derives predicted motion information using the information acquired in step S422. Specifically, the inter prediction unit 208 acquires motion information of a decoded block that is spatially or temporally adjacent to the current block to be decoded, and derives predicted motion information using the acquired motion information ( S461).

First, the inter prediction unit 208 generates a parallel movement component from the differential motion information and predicted motion information (S462). FIG. 25 is a flowchart of this parallel movement component generation process (S462).

First, the inter prediction unit 208 determines whether a differential translation component has been acquired in step S421 (S481).

If a differential translation component has been acquired (Yes in S481), the inter prediction unit 208 determines whether a parallel component exists in the predicted motion information acquired in step S461 (S482).

If there is no parallel movement in the predicted motion information (No in S482), the inter prediction unit 208 sets the predicted parallel movement component to 0 (S483). If the predicted motion information includes a translation component (Yes in S482), the inter prediction unit 208 sets the translation component of the predicted motion information as the predicted translation component (S484).

The inter prediction unit 208 generates a translation component by adding the predicted translation component acquired in step S483 or S484 to the difference translation component (S485).

If there is no differential translation component (No in S482), the inter prediction unit 208 ends the process regarding the translation component (S462).

Next, the inter prediction unit 208 generates a rotation component from the differential motion information and predicted motion information (S463). FIG. 26 is a flowchart of this rotation component generation process (S463).

First, the inter prediction unit 208 determines whether a differential rotation component has been acquired in step S421 (S501).

If a differential rotation component has been acquired (Yes in S501), the inter prediction unit 208 determines whether a rotation component exists in the predicted motion information acquired in step S461 (S502).

If rotation does not exist in the predicted motion information (No in S502), the inter prediction unit 208 sets the predicted rotation component to 0 (S503). If a rotational component exists in the predicted motion information (Yes in S502), the inter prediction unit 208 sets the rotational component of the predicted motion information as a predicted rotational component (S504).

The inter prediction unit 208 generates a rotation component by adding the predicted rotation component acquired in step S503 or S504 to the difference rotation component (S505).

If there is no differential rotation component (No in S501), the inter prediction unit 208 ends the process regarding the rotation component (S463).

Subsequently, the inter prediction unit 208 generates a scaling component from the differential motion information and predicted motion information (S464). FIG. 27 is a flowchart of this scaling component generation process (S464).

First, the inter prediction unit 208 determines whether a differential scaling component has been acquired in step S421 (S521).

If a differential scaling component has been acquired (Yes in S521), the inter prediction unit 208 determines whether a scaling component exists in the predicted motion information acquired in step S461 (S522).

If scaling does not exist in the predicted motion information (No in S522), the inter prediction unit 208 sets the predicted scaling component to 1 (S523). If a scaling component exists in the predicted motion information (Yes in S523), the inter prediction unit 208 sets the scaling component of the predicted motion information as a predicted scaling component (S524).

The inter prediction unit 208 generates a scaling component by adding the predicted scaling component acquired in steps S523 and S524 to the difference scaling component (S525).

If the differential scaling component does not exist (No in S521), the inter prediction unit 208 ends the process regarding the scaling component (S464).

Finally, the inter prediction unit 208 generates a shear component from the differential motion information and predicted motion information (S465). FIG. 28 is a flowchart of this shear component generation process (S465).

First, the inter prediction unit 208 determines whether a differential shear component has been obtained in step S421 (S541).

If a differential shear component has been acquired (Yes in S541), the inter prediction unit 208 determines whether a shear component is present in the predicted motion information acquired in step S461 (S542).

If shear does not exist in the predicted motion information (No in S542), the inter prediction unit 208 sets the predicted shear component to 0 (S543). If the predicted motion information includes a shear component (Yes in S542), the inter prediction unit 208 sets the shear component of the predicted motion information as the predicted shear component (S544).

The inter prediction unit 208 generates a shear component by adding the predicted shear component acquired in steps S543 and S544 to the difference shear component (S545).

If no differential shear component exists (No in S541), the inter prediction unit 208 ends the processing related to the shear component (S465).

After performing these series of processes for each block, the inter prediction unit 208 ends the motion information generation process (S423).

Note that, as described in Embodiment 1, each flag may be provided for each block, or may be provided for each image, each sequence, or each region into which an image is divided. If a flag is set in a unit other than a block and a transform component is specified by the flag, the image decoding device uses the same type of transform component for all blocks included in the specified unit. perform decryption processing. Thereby, the image decoding device can omit determination steps and the like, and can perform decoding processing with high prediction accuracy with a small amount of information and a small processing load.

Further, as in the first embodiment, the order of the generation processing (S462 to S465) of various transformation components is not limited to the order shown in FIG. 24. Furthermore, some or all of the processes in steps S462 to S465 may be performed in parallel. Alternatively, these processes may be prioritized and performed in order of priority.

Further, as in the second embodiment, when encoding level information indicating encoding levels is used instead of various flags, image decoding device 200 uses bits of encoding level information instead of the various flags described above. Decode from stream 221. Further, the image decoding device uses information indicated by encoding level information instead of various flags to determine the presence or absence of a transformed component.

Further, as described in Embodiment 1, when the presence or absence of various transformation components is specified by the block size, the image decoding device 200 decodes the block size from the bitstream 221 and converts the block size into is used to determine the presence or absence of various conversion components.

(effect)
As described above, the image decoding device 200 according to the present embodiment can decode the bitstream 221 in which only the transform components necessary to generate a predictive block are encoded. In addition, the image decoding device 200 can decode the bitstream 221 generated so as to reduce the amount of code using high-dimensional motion prediction, so it is possible to reproduce a higher quality image.

In this embodiment, an example has been described in which the motion information includes translation, rotation, scaling, and shearing as transformation components, but the transformations that can be used are not limited to these. For example, a trapezoidal transformation may be used. This allows complex transformations to be expressed, so the image decoding device can generate a predicted image with higher accuracy.

That is, the image decoding device 200 according to the present embodiment only needs to be able to divide motion information into a plurality of transform components and determine whether to decode each transform component. That is, the image decoding device 200 may use transformation components other than those described above.

Furthermore, the method of this embodiment can be applied not only to the case of decoding differential motion information that is the difference between motion information and predicted motion information, but also to, for example, a merge mode.

(Embodiment 5)
In the first to fourth embodiments described above, examples are described in which affine transformation is used for inter prediction, but in this embodiment, an example in which affine transformation is used in intra prediction is described.

As shown in FIG. 29, the image encoding device (or image decoding device) according to the present embodiment calculates the pixel values of already processed (encoded or decoded) blocks in the same picture as the current block. Used as the pixel value of the current block. That is, the pixel values of the processed block are copied to the current block. Furthermore, in this embodiment, as shown in FIG. 30, various transformations such as not only parallel movement but also rotation, scaling, and shearing are used during this copying.

That is, in this embodiment, the intra prediction unit 109 (or 205) generates a predicted block using reference information indicating a processed block. This reference information includes various transformation components such as a translation component, a rotation component, a scaling component, and a shear component.

In such a case, as in the above-mentioned embodiments 1 to 4, any transform component can be selectively used by encoding (or decoding) information (various flags or encoding levels) indicating whether each of the various transform components is to be used or not.

Note that in intra prediction, among rotation, scaling, and shearing, scaling, rotation, and shearing tend to contribute to improving prediction accuracy in this order. Therefore, it is preferable to assign priorities in this order. Note that the method described in Embodiment 3 can be used as a method for prioritizing a plurality of conversions.

The priority may be changed depending on the type of image. For example, for natural images, the priority may be set in the order of zoom, rotation, and shear, while for screen content such as map information, the priority may be set in the order of rotation, zoom, and shear.

As described above in Embodiments 1 to 3 and 5, the image encoding apparatus according to the embodiment is an image encoding apparatus that encodes an image, and performs the processing shown in FIG. 31.

First, the image encoding device selects two or more transform components from among a plurality of transform components including a parallel component and a plurality of non-translation components as reference information indicating a reference destination of a current block to be encoded. (S601). Here, the reference information is information indicating motion information in inter prediction or a processed block as a reference destination in intra prediction. Further, the plurality of non-translation components include, for example, a rotation component, a scaling component, and a shear component.

Next, the image encoding device generates a predicted image using the reference information (S602). Next, the image encoding device encodes the current block using the predicted image (S603).

The image encoding device also encodes selection information for specifying two or more selected transform components from among the plurality of transform components (S604). For example, the selection information includes flags (parallel movement flag, rotation flag, scaling flag, and shear flag) that correspond to each of the plurality of transformation components and indicate whether the corresponding transformation component has been selected. Alternatively, the selection information is a set including some or all of a plurality of transform components, and indicates one encoding level from a plurality of encoding levels indicating mutually different sets. In this case, in step S601, two or more transform components included in the set indicated by the encoding level indicated by the selection information are selected.

Furthermore, the image encoding device may encode the selection information for each block, each picture, each sequence, or each region into which a picture is divided. It may also be encoded. In other words, the image encoding device may encode one piece of selection information that is commonly used for images that include the current block, or encode one piece of selection information that is commonly used for sequences that include the current block. Alternatively, one piece of selection information commonly used for the area including the current block may be encoded.

Next, the image encoding device encodes reference information of the current block using reference information of an encoded block different from the current block (S605). For example, the image encoding device encodes differential reference information that is a difference between the reference information of the encoded block and the reference information of the current block.

In addition, in step S601, the image encoding device may select two or more transform components depending on the size of the current block. In this case, the selection information indicates the size of the current block. For example, the selection information includes information indicating the size of the maximum coding unit (CU) and information indicating whether or not each coding unit is to be further divided.

Further, for example, the image encoding device does not select the shear component when the size of the current block is less than the first threshold.

Further, in step S601, the image encoding device may select two or more transformation components, giving priority to the translation component, rotation component, scaling component, and shear component in this order. For example, the priority can be set using the method described in Embodiment 3.

Further, as described in Embodiments 4 and 5, the image decoding device according to the embodiment is an image decoding device that decodes a bitstream obtained by encoding an image, and is shown in FIG. Perform the processing shown.

First, the image decoding device decodes selection information for specifying two or more transform components from a plurality of transform components including a parallel component and a plurality of non-transform components from a bitstream (S611). Here, the plurality of non-translation components include, for example, a rotation component, a scaling component, and a shear component. Further, the selection information includes, for example, flags (parallel movement flag, rotation flag, scaling flag, and shearing flag) that correspond to each of the plurality of transformation components and indicate whether the corresponding transformation component has been selected. Alternatively, the selection information is a set including some or all of a plurality of transform components, and indicates one encoding level from a plurality of encoding levels indicating mutually different sets.

Further, the image decoding device may decode the selection information block by block, picture by picture, sequence by sequence, or region by region into which a picture is divided. You may. In other words, the image decoding device may decode one selection information that is commonly used for images that include the current block, or may decode one selection information that is commonly used for sequences that include the current block. Alternatively, one selection information commonly used for the area including the current block may be decoded.

Further, the image decoding device selects two or more transform components specified by the decoded selection information as reference information indicating the reference destination of the current block to be decoded (S612). Here, the reference information is information indicating motion information in inter prediction or a processed block as a reference destination in intra prediction. Note that when the selection information indicates a coding level, the image decoding device selects two or more transform components included in the set indicated by the coding level indicated by the selection information.

Next, the image decoding device decodes the reference information of the current block from the bitstream using reference information of a decoded block different from the current block (S613). Specifically, the image decoding device decodes the difference reference information of the selected transform component from the bitstream. Next, the image decoding device generates reference information by adding the obtained differential decoding information and the reference information of the decoded block for each selected transformation component.

Next, the image decoding device generates a predicted image using the reference information (S614). Next, the image decoding device decodes the current block from the bitstream using the predicted image (S615).

Note that the selection information indicates the size of the current block, and in step S612, the image decoding device may select two or more transform components depending on the size of the current block. For example, the selection information includes information indicating the size of the maximum coding unit (CU) and information indicating whether each coding unit is further divided. The image decoding device uses this information to determine the current block size.

Further, for example, the image decoding device does not select the shear component when the size of the current block is less than or equal to the first threshold.

Further, in step S612, the image encoding device may select two or more transformation components, giving priority to the translation component, rotation component, scaling component, and shear component in this order. For example, the priority can be set using the method described in Embodiment 3.

Although the image encoding method and image decoding method according to the embodiment have been described above, the present invention is not limited to this embodiment.

Further, each processing unit included in the image encoding device and the image decoding device according to the above embodiments is typically realized as an LSI, which is an integrated circuit. These may be individually integrated into one chip, or may be integrated into one chip including some or all of them.

Further, circuit integration is not limited to LSI, and may be realized using a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured, or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used.

In each of the embodiments described above, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU or a processor reading and executing a software program recorded on a recording medium such as a hard disk or a semiconductor memory.

In other words, the image encoding device and the image decoding device include a processing circuit and a storage electrically connected to the processing circuit (accessible from the control circuit). The processing circuit includes at least one of dedicated hardware and a program execution unit. Further, when the processing circuit includes a program execution section, the storage device stores a software program executed by the program execution section. The processing circuit executes the encoding method or decoding method according to the above embodiment using the storage device.

Furthermore, the present invention may be the above-mentioned software program, or may be a non-transitory computer-readable recording medium on which the above-mentioned program is recorded. Furthermore, it goes without saying that the above program can be distributed via a transmission medium such as the Internet.

Moreover, all the numbers used above are exemplified to specifically explain the present invention, and the present invention is not limited to the illustrated numbers.

The division of functional blocks in the block diagram is one example, and multiple functional blocks may be realized as one functional block, one functional block may be divided into multiple blocks, or some functions may be transferred to other functional blocks. Furthermore, the functions of multiple functional blocks having similar functions may be processed in parallel or in a time-shared manner by a single piece of hardware or software.

Furthermore, the order in which the steps included in the above encoding method or decoding method are executed is merely an example for specifically explaining the present invention, and an order other than the above may be used. Further, some of the above steps may be executed simultaneously (in parallel) with other steps.

The encoding device and decoding device according to one or more aspects of the present invention have been described above based on the embodiments, but the present invention is not limited to these embodiments. Unless departing from the spirit of the present invention, various modifications that can be thought of by those skilled in the art to this embodiment, and embodiments constructed by combining components of different embodiments may also be applied to one or more of the present invention. may be included within the scope of the embodiments.

(Embodiment 6)
Each of the above embodiments can be implemented by recording a program for realizing the configuration of the moving image encoding method (image encoding method) or the moving image decoding method (image decoding method) shown in each of the above embodiments on a storage medium. It becomes possible to easily implement the processing shown in the form in an independent computer system. The storage medium may be anything that can record a program, such as a magnetic disk, optical disk, magneto-optical disk, IC card, or semiconductor memory.

Further, here, application examples of the moving picture encoding method (image encoding method) and the moving picture decoding method (image decoding method) shown in each of the above embodiments and a system using the same will be explained. The system is characterized by having an image encoding/decoding device including an image encoding device using an image encoding method and an image decoding device using an image decoding method. Other configurations in the system can be changed as appropriate.

FIG. 33 is a diagram showing the overall configuration of a content supply system ex100 that implements a content distribution service. The communication service provision area is divided into desired sizes, and base stations ex106, ex107, ex108, ex109, and ex110, which are fixed wireless stations, are installed in each cell.

This content supply system ex100 is connected to the Internet ex101 via an Internet service provider ex102, a telephone network ex104, and base stations ex106 to ex110, and various devices such as a computer ex111, a PDA (Personal Digital Assistant) ex112, a camera ex113, a mobile phone ex114, and a game console ex115.

However, the content supply system ex100 is not limited to the configuration shown in FIG. 33, and any of the elements may be combined and connected. Furthermore, each device may be directly connected to the telephone network ex104 without going through the base stations ex106 to ex110, which are fixed wireless stations. Further, each device may be directly connected to each other via short-range wireless or the like.

Camera ex113 is a device capable of shooting moving images, such as a digital video camera, and camera ex116 is a device capable of shooting still images and moving images, such as a digital camera. Furthermore, mobile phone ex114 can be any of the following: a GSM (registered trademark) (Global System for Mobile Communications) type, a CDMA (Code Division Multiple Access) type, a W-CDMA (Wideband-Code Division Multiple Access) type, an LTE (Long Term Evolution) type, a HSPA (High Speed Packet Access) mobile phone, or a PHS (Personal Handyphone System).

In the content supply system ex100, a camera ex113 and the like is connected to a streaming server ex103 through a base station ex109 and a telephone network ex104, thereby enabling live distribution and the like. In live distribution, the content (for example, video of live music) that the user shoots using the camera EX113 is encoded as described in each of the above embodiments (that is, according to one aspect of the present invention). (functioning as such an image encoding device), and transmits it to the streaming server ex103. On the other hand, the streaming server ex103 streams the transmitted content data to the client that has made the request. Examples of clients include a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114, a game machine ex115, etc., which are capable of decoding the encoded data. Each device that receives the distributed data decodes and reproduces the received data (that is, functions as an image decoding device according to one aspect of the present invention).

Note that the encoding process of the photographed data may be performed by the camera ex113, the streaming server ex103 that performs the data transmission process, or the encoding process may be shared between the two parties. Similarly, the decoding process for distributed data may be performed by the client, by the streaming server ex103, or by each other. Further, still images and/or moving image data taken not only by the camera ex113 but also by the camera ex116 may be transmitted to the streaming server ex103 via the computer ex111. The encoding process in this case may be performed by the camera ex116, the computer ex111, or the streaming server ex103, or may be shared between them.

Further, these encoding/decoding processes are generally performed in the computer ex111 or the LSI ex500 included in each device. The LSIex 500 may be a single chip or may have a configuration consisting of multiple chips. In addition, the software for video encoding/decoding is embedded in some kind of recording medium (CD-ROM, flexible disk, hard disk, etc.) that can be read by a computer such as EX111, and the encoding/decoding process is performed using that software. You can. Furthermore, if the mobile phone ex114 is equipped with a camera, video data acquired by the camera may be transmitted. The video data at this time is data encoded by the LSI ex500 included in the mobile phone ex114.

Furthermore, the streaming server ex103 may be a plurality of servers or a plurality of computers that process, record, or distribute data in a distributed manner.

As described above, in the content supply system ex100, the client can receive and reproduce encoded data. In this way, in the content supply system ex100, the client can receive, decode, and reproduce information transmitted by the user in real time, and even users without special rights or equipment can realize personal broadcasting.

Note that not only the example of the content supply system ex100 but also the digital broadcasting system ex200 as shown in FIG. (image decoding device). Specifically, at the broadcasting station ex201, multiplexed data in which music data and the like are multiplexed with video data is communicated or transmitted to the satellite ex202 via radio waves. This video data is data encoded by the video encoding method described in each of the above embodiments (that is, data encoded by an image encoding device according to one aspect of the present invention). The broadcasting satellite ex202 that receives this transmits radio waves for broadcasting, and the radio waves are received by a home antenna ex204 capable of receiving satellite broadcasting. A device such as a television (receiver) EX300 or a set-top box (STB) EX217 decodes and reproduces the received multiplexed data (that is, functions as an image decoding device according to one aspect of the present invention).

It is also used as a reader/recorder ex218 that reads and decodes multiplexed data recorded on a recording medium ex215 such as a DVD or BD, or encodes a video signal on the recording medium ex215, and in some cases multiplexes it with a music signal and writes it. It is possible to implement the video decoding device or video encoding device shown in each of the above embodiments. In this case, the reproduced video signal is displayed on the monitor ex219, and the video signal can be reproduced in other devices or systems using the recording medium ex215 on which the multiplexed data is recorded. Alternatively, a moving image decoding device may be installed in a set-top box ex217 connected to a cable ex203 for cable television or an antenna ex204 for satellite/terrestrial broadcasting, and displayed on a television monitor ex219. At this time, the video decoding device may be incorporated into the television instead of the set-top box.

FIG. 35 is a diagram showing a television (receiver) ex300 using the video decoding method and video encoding method described in each of the above embodiments. The TV EX300 includes a tuner EX301 that obtains or outputs multiplexed data in which audio data is multiplexed with video data via an antenna EX204 or a cable EX203 that receives the above broadcast, and a tuner EX301 that demodulates the received multiplexed data. Alternatively, a modulation/demodulation unit ex302 modulates multiplexed data to be transmitted to the outside, and separates the demodulated multiplexed data into video data and audio data, or video data and audio data encoded by a signal processing unit ex306. A multiplexing/demultiplexing unit ex303 is provided.

The television ex300 also includes an audio signal processing unit ex304 and a video signal processing unit ex305 (an image encoding device according to one aspect of the present invention or an image The output unit ex309 includes a signal processing unit ex306 which functions as a decoding device), a speaker ex307 which outputs a decoded audio signal, and a display unit ex308 such as a display which displays a decoded video signal. Furthermore, the television ex300 includes an interface section ex317 having an operation input section ex312 and the like that accepts input of user operations. Furthermore, the television ex300 includes a control section ex310 that controls each section in an integrated manner, and a power supply circuit section ex311 that supplies power to each section. In addition to the operation input unit ex312, the interface unit ex317 includes a bridge ex313 that connects to external devices such as a reader/recorder ex218, a slot unit ex314 for allowing the installation of a recording medium ex216 such as an SD card, and an external recording device such as a hard disk. It may include a driver ex315 for connecting to the media, a modem ex316 for connecting to the telephone network, and the like. Note that the recording medium ex216 is capable of electrically recording information using a nonvolatile/volatile semiconductor memory element for storing information. Each part of the television ex300 is connected to each other via a synchronous bus.

First, a configuration in which the television ex300 decodes and reproduces multiplexed data acquired from the outside using the antenna ex204 or the like will be described. The television ex300 receives a user operation from a remote controller ex220 or the like, and demultiplexes the multiplexed data demodulated by a modulation/demodulation unit ex302 at a multiplexing/demultiplexing unit ex303 under the control of a control unit ex310 having a CPU or the like. Further, in the television ex300, the audio signal processing unit ex304 decodes the separated audio data, and the video signal processing unit ex305 decodes the separated video data using the decoding method described in each of the above embodiments. The decoded audio signal and video signal are each outputted to the outside from the output unit ex309. When outputting, it is preferable to temporarily store these signals in buffers ex318, ex319, etc. so that the audio signals and video signals can be reproduced in synchronization. Furthermore, the television ex300 may read multiplexed data from recording media ex215 and ex216 such as magnetic/optical disks and SD cards, rather than from broadcasting or the like. Next, a configuration in which the television ex300 encodes an audio signal and a video signal and transmits it to the outside or writes it on a recording medium or the like will be described. The television ex300 receives a user operation from a remote controller ex220 or the like, and based on the control of a control unit ex310, an audio signal processing unit ex304 encodes an audio signal, and a video signal processing unit ex305 encodes a video signal according to each of the above embodiments. Encode using the encoding method described in . The encoded audio and video signals are multiplexed by a multiplex/separator ex303 and output to the outside. When multiplexing, it is preferable to temporarily store these signals in buffers ex320, ex321, etc. so that the audio signals and video signals are synchronized. Note that a plurality of buffers ex318, ex319, ex320, and ex321 may be provided as illustrated, or a configuration may be adopted in which one or more buffers are shared. Further, in addition to what is shown, data may be stored in a buffer between the modulation/demodulation section ex302 and the multiplexing/separation section ex303 as a buffer to prevent system overflow and underflow.

In addition to acquiring audio and video data from broadcasting and recording media, the TV EX300 is also equipped with a configuration that accepts AV input from microphones and cameras, and performs encoding processing on the data acquired from them. Good too. Although the TV EX300 has been described here as being configured to be capable of the above-mentioned encoding processing, multiplexing, and external output, it cannot perform these processes and is only capable of the above-mentioned reception, decoding processing, and external output. It may be a configuration.

In addition, when the reader/recorder ex218 reads or writes multiplexed data from a recording medium, the above-mentioned decoding or encoding process may be performed by either the television ex300 or the reader/recorder ex218, or the television ex300 and the reader/recorder ex218 may share the same role.

As an example, FIG. 36 shows the configuration of the information reproducing/recording section ex400 when reading or writing data from an optical disc. The information reproducing/recording unit ex400 includes elements ex401, ex402, ex403, ex404, ex405, ex406, and ex407 described below. The optical head ex401 writes information by irradiating the recording surface of the recording medium ex215, which is an optical disk, with a laser spot, and reads the information by detecting reflected light from the recording surface of the recording medium ex215. The modulation recording unit ex402 electrically drives a semiconductor laser built into the optical head ex401 and modulates the laser beam according to recording data. The reproduction demodulation unit EX403 amplifies the reproduction signal which electrically detects the reflected light from the recording surface by the photodetector built into the optical head EX401, separates and demodulates the signal components recorded on the recording medium EX215, and performs the necessary Play back information. The buffer ex404 temporarily holds information to be recorded on the recording medium ex215 and information reproduced from the recording medium ex215. The disk motor ex405 rotates the recording medium ex215. The servo control unit ex406 moves the optical head ex401 to a predetermined information track while controlling the rotational drive of the disk motor ex405, and performs laser spot tracking processing. The system control unit ex407 controls the entire information reproducing/recording unit ex400. For the above read and write processing, the system control unit ex407 uses various information held in the buffer ex404, and generates and adds new information as necessary. This is realized by recording and reproducing information through the optical head ex401 while coordinating the ex403 and servo control unit ex406. The system control unit ex407 is composed of, for example, a microprocessor, and executes these processes by executing read and write programs.

Although the optical head ex401 has been described above as emitting a laser spot, it may be configured to perform higher-density recording using near-field light.

FIG. 37 shows a schematic diagram of the recording medium ex215, which is an optical disc. A guide groove is formed in a spiral shape on the recording surface of the recording medium ex215, and address information indicating an absolute position on the disk is recorded in advance in the information track ex230 by a change in the shape of the groove. This address information includes information for specifying the position of the recording block ex231, which is a unit for recording data, and the recording block can be specified by reproducing the information track ex230 and reading the address information in a recording or reproducing device. Can be done. Furthermore, the recording medium ex215 includes a data recording area ex233, an inner circumferential area ex232, and an outer circumferential area ex234. The area used for recording user data is the data recording area ex233, and the inner circumferential area ex232 and outer circumferential area ex234, which are arranged on the inner or outer circumference of the data recording area ex233, are used for specific purposes other than recording user data. used. The information reproducing/recording unit ex400 reads and writes encoded audio data, video data, or multiplexed data obtained by multiplexing these data into the data recording area ex233 of the recording medium ex215.

Although the above description has been made using single-layer optical discs such as DVDs and BDs, the invention is not limited to these, and may be optical discs that have a multilayer structure and can record on surfaces other than the surface. In addition, optical discs have a structure that allows multidimensional recording/reproduction, such as recording information in the same place on the disc using light of various different wavelengths and recording different layers of information from various angles. It may be.

Further, in the digital broadcasting system EX200, it is also possible to receive data from a satellite EX202 or the like in a car EX210 having an antenna EX205, and to reproduce a moving image on a display device such as a car navigation EX211 included in the car EX210. Note that the configuration of the car navigation ex211 can be, for example, the configuration shown in FIG. 35 with a GPS reception section added, and the same can be considered for the computer ex111, the mobile phone ex114, etc.

Figure 38A is a diagram showing a mobile phone ex114 using the video decoding method and video encoding method described in the above embodiment. The mobile phone ex114 includes an antenna ex350 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex365 capable of taking videos and still images, and a display unit ex358 such as a liquid crystal display that displays decoded data of videos captured by the camera unit ex365 and videos received by the antenna ex350. The mobile phone ex114 further includes a main body unit having an operation key unit ex366, an audio output unit ex357 such as a speaker for outputting audio, an audio input unit ex356 such as a microphone for inputting audio, a memory unit ex367 for storing captured videos, still images, recorded audio, or encoded or decoded data such as received videos, still images, and emails, or a slot unit ex364 that is an interface unit with a recording medium for similarly storing data.

Furthermore, a configuration example of the mobile phone ex114 will be described using FIG. 38B. The mobile phone EX114 has a main control unit EX360 that comprehensively controls each part of the main body including a display unit EX358 and an operation key unit EX366, a power supply circuit unit EX361, an operation input control unit EX362, and a video signal processing unit EX355. , camera interface section ex363, LCD (Liquid Crystal Display) control section ex359, modulation/demodulation section ex352, multiplexing/separation section ex353, audio signal processing section ex354, slot section ex364, and memory section ex367 are connected to each other via bus ex370. ing.

When the user ends the call and turns on the power key, the power supply circuit section ex361 starts the mobile phone ex114 into an operable state by supplying power to each section from the battery pack.

Based on the control of the main control unit ex360 having a CPU, ROM, RAM, etc., the mobile phone ex114 converts the voice signal picked up by the voice input unit ex356 in the voice call mode into a digital voice signal in the voice signal processing unit ex354, which then undergoes spectrum spreading processing in the modulation/demodulation unit ex352, digital-to-analog conversion processing and frequency conversion processing in the transmission/reception unit ex351, and transmits the signal via the antenna ex350. In addition, the mobile phone ex114 amplifies the received data received via the antenna ex350 in the voice call mode, and then undergoes frequency conversion processing and analog-to-digital conversion processing, spectrum despreading processing in the modulation/demodulation unit ex352, and conversion to an analog voice signal in the voice signal processing unit ex354, which is then output from the voice output unit ex357.

Further, when transmitting an e-mail in the data communication mode, the text data of the e-mail input by operating the operation key section ex366 or the like on the main body is sent to the main control section ex360 via the operation input control section ex362. The main control unit ex360 performs spectrum spread processing on the text data in the modulation/demodulation unit ex352, performs digital-to-analog conversion processing and frequency conversion processing in the transmission/reception unit ex351, and then transmits the text data to the base station ex110 via the antenna ex350. . When receiving an e-mail, the received data undergoes almost the opposite process and is output to the display section ex358.

When transmitting video, still images, or video and audio in the data communication mode, the video signal processing unit ex355 compresses the video signal supplied from the camera unit ex365 using the video encoding method described in each of the above embodiments. It encodes (that is, functions as an image encoding device according to one aspect of the present invention) and sends the encoded video data to the multiplexing/separating unit ex353. In addition, the audio signal processing unit ex354 encodes the audio signal collected by the audio input unit ex356 while the camera unit ex365 captures a video, still image, etc., and sends the encoded audio data to the multiplexing/separating unit ex353. do.

The multiplexing/separation unit ex353 multiplexes the encoded video data supplied from the video signal processing unit ex355 and the encoded audio data supplied from the audio signal processing unit ex354 using a predetermined method, and the resulting multiplexed data is subjected to spectrum spreading processing in the modulation/demodulation unit (modulation/demodulation circuit unit) ex352, and then digital-to-analog conversion processing and frequency conversion processing in the transmission/reception unit ex351, before being transmitted via the antenna ex350.

When receiving video file data linked to a homepage etc. in data communication mode, or receiving an e-mail with video and/or audio attached, decode the multiplexed data received via the antenna EX350. In order to do this, the multiplexing/demultiplexing unit ex353 separates the multiplexed data into a video data bit stream and an audio data bit stream, and performs video signal processing on the encoded video data via the synchronous bus ex370. At the same time, the encoded audio data is supplied to the audio signal processing section ex354. The video signal processing unit ex355 decodes the video signal by decoding it using a video decoding method that corresponds to the video encoding method shown in each of the above embodiments (i.e., the video signal according to one aspect of the present invention). For example, videos and still images included in a moving image file linked to a home page are displayed from a display unit ex358 via an LCD control unit ex359 (functioning as a decoding device). The audio signal processing unit ex354 decodes the audio signal, and the audio output unit ex357 outputs audio.

In addition, terminals such as the above-mentioned mobile phone EX114, like the TV EX300, can be called transmitting/receiving terminals that have both an encoder and a decoder, as well as transmitting terminals that have only an encoder and receiving terminals that have only a decoder. Three implementation formats are possible. Furthermore, although it has been explained that the digital broadcasting system EX200 receives and transmits multiplexed data in which music data, etc. are multiplexed with video data, data in which text data related to video, etc., is multiplexed in addition to audio data. or may be the video data itself instead of the multiplexed data.

In this way, it is possible to use the video encoding method or video decoding method shown in each of the above embodiments in any of the above devices and systems, and by doing so, it is possible to obtain the effects described in each of the above embodiments.

Furthermore, the present invention is not limited to the above-described embodiments, and various modifications and changes can be made without departing from the scope of the present invention.

(Embodiment 7)
The video encoding method or device shown in each of the above embodiments and the video encoding method or device compliant with different standards such as MPEG-2, MPEG4-AVC, or VC-1 can be switched as necessary. By doing so, it is also possible to generate video data.

When multiple pieces of video data that comply with different standards are generated, it is necessary to select a decoding method that corresponds to each standard when decoding. However, because it is not possible to identify which standard the video data to be decoded complies with, a problem arises in that it is not possible to select an appropriate decoding method.

To solve this problem, multiplexed data, which is video data multiplexed with audio data, etc., is configured to include identification information indicating which standard the video data complies with. The specific configuration of multiplexed data including video data generated by the video encoding methods or devices shown in each of the above embodiments is described below. The multiplexed data is a digital stream in the MPEG-2 transport stream format.

FIG. 39 is a diagram showing the structure of multiplexed data. As shown in FIG. 39, multiplexed data is obtained by multiplexing one or more of a video stream, an audio stream, a presentation graphics stream (PG), and an interactive graphics stream. The video stream shows the main video and sub-video of the movie, the audio stream (IG) shows the main audio part of the movie and the sub-audio to be mixed with the main audio, and the presentation graphics stream shows the subtitles of the movie. Here, the main image refers to the normal image displayed on the screen, and the sub-image refers to the image displayed on a small screen within the main image. Furthermore, the interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen. The video stream is encoded by the video encoding method or device shown in each of the above embodiments or by the video encoding method or device compliant with conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. ing. The audio stream is encoded using a method such as Dolby AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, or linear PCM.

Each stream included in the multiplexed data is identified by a PID. For example, the video stream used for movie images is 0x1011, the audio stream is 0x1100 to 0x111F, the presentation graphics is 0x1200 to 0x121F, and the interactive graphics stream is 0x1400 to 0x141F. 0x1B00 to 0x1B1F are assigned to the video stream used for the sub-video, and 0x1A00 to 0x1A1F are assigned to the audio stream used for the sub-audio to be mixed with the main audio.

FIG. 40 is a diagram schematically showing how multiplexed data is multiplexed. First, a video stream ex235 consisting of a plurality of video frames and an audio stream ex238 consisting of a plurality of audio frames are converted into PES packet sequences ex236 and ex239, respectively, and then into TS packets ex237 and ex240. Similarly, the data of presentation graphics stream ex241 and interactive graphics ex244 are converted into PES packet sequences ex242 and ex245, respectively, and further converted into TS packets ex243 and ex246. The multiplexed data ex247 is constructed by multiplexing these TS packets into one stream.

FIG. 41 shows in more detail how video streams are stored in PES packet sequences. The first row in FIG. 41 shows a video frame sequence of the video stream. The second row shows a PES packet sequence. As shown by arrows yy1, yy2, yy3, and yy4 in FIG. 41, I pictures, B pictures, and P pictures, which are a plurality of Video Presentation Units in a video stream, are divided into pictures and stored in the payload of a PES packet. . Each PES packet has a PES header, and the PES header stores a PTS (Presentation Time-Stamp), which is a picture display time, and a DTS (Decoding Time-Stamp), which is a picture decoding time.

FIG. 42 shows the format of the TS packet finally written into the multiplexed data. A TS packet is a 188-byte fixed-length packet consisting of a 4-byte TS header with information such as a PID that identifies a stream, and a 184-byte TS payload that stores data, and the above PES packet is divided and stored in the TS payload. Ru. In the case of a BD-ROM, a 4-byte TP_Extra_Header is added to the TS packet, forming a 192-byte source packet, which is written into multiplexed data. Information such as ATS (Arrival_Time_Stamp) is written in TP_Extra_Header. ATS indicates the start time of transfer of the TS packet to the PID filter of the decoder. Source packets are arranged in the multiplexed data as shown in the lower part of FIG. 42, and the number incremented from the beginning of the multiplexed data is called an SPN (source packet number).

In addition to streams such as video, audio, and subtitles, the TS packets included in the multiplexed data include PAT (Program Association Table), PMT (Program Map Table), PCR (Program Clock Reference), and the like. The PAT indicates what the PID of the PMT used in the multiplexed data is, and the PID of the PAT itself is registered as 0. The PMT has the PID of each stream such as video, audio, subtitles, etc. included in the multiplexed data and attribute information of the stream corresponding to each PID, and also has various descriptors regarding the multiplexed data. The descriptor includes copy control information that instructs whether copying of multiplexed data is permitted or not. PCR corresponds to an ATS in which the PCR packet is transferred to a decoder in order to synchronize the ATC (Arrival Time Clock), which is the time axis of ATS, and the STC (System Time Clock), which is the time axis of PTS/DTS. Contains STC time information.

FIG. 43 is a diagram illustrating the data structure of PMT in detail. A PMT header that describes the length of data included in the PMT is placed at the beginning of the PMT. After that, a plurality of descriptors related to multiplexed data are arranged. The above copy control information and the like are written as a descriptor. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information includes a stream descriptor in which stream type, stream PID, and stream attribute information (frame rate, aspect ratio, etc.) are described to identify the compression codec of the stream. There are as many stream descriptors as there are streams in the multiplexed data.

When recording on a recording medium or the like, the multiplexed data is recorded together with a multiplexed data information file.

The multiplexed data information file, as shown in FIG. 44, is management information for multiplexed data, has a one-to-one correspondence with multiplexed data, and is composed of multiplexed data information, stream attribute information, and an entry map.

As shown in FIG. 44, the multiplexed data information is composed of a system rate, a playback start time, and a playback end time. The system rate indicates the maximum transfer rate of multiplexed data to a PID filter of a system target decoder, which will be described later. The interval between ATSs included in the multiplexed data is set to be less than or equal to the system rate. The playback start time is set to the PTS of the first video frame of the multiplexed data, and the playback end time is set to the PTS of the last video frame of the multiplexed data plus a playback interval of one frame.

As for the stream attribute information, as shown in FIG. 45, attribute information for each stream included in the multiplexed data is registered for each PID. The attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. Video stream attribute information includes information such as what kind of compression codec the video stream was compressed with, what the resolution of the individual picture data that makes up the video stream is, what the aspect ratio is, and what the frame rate is. It has information such as how much. Audio stream attribute information includes information such as what compression codec the audio stream was compressed with, how many channels it contains, what language it supports, what the sampling frequency is, etc. It has information on This information is used for initializing the decoder before playback by the player.

In this embodiment, of the multiplexed data, the stream type included in the PMT is used. Furthermore, if multiplexed data is recorded on the recording medium, video stream attribute information included in the multiplexed data information is used. Specifically, in the video encoding method or apparatus shown in each of the above embodiments, the video encoding method shown in each of the above embodiments is performed on the stream type or video stream attribute information included in the PMT. A step or means for setting unique information indicating that the video data is generated by the method or device is provided. With this configuration, it is possible to distinguish between video data generated by the video encoding method or device shown in each of the above embodiments and video data compliant with other standards.

Further, FIG. 46 shows the steps of the moving image decoding method in this embodiment. In step exS100, the stream type included in the PMT or the video stream attribute information included in the multiplexed data information is acquired from the multiplexed data. Next, in step exS101, it is determined whether the stream type or video stream attribute information indicates that it is multiplexed data generated by the video encoding method or device shown in each of the above embodiments. do. If it is determined that the stream type or video stream attribute information is generated by the video encoding method or device shown in each of the above embodiments, in step exS102, the video stream attribute information is Decoding is performed using the moving image decoding method shown in the figure below. Furthermore, if the stream type or video stream attribute information indicates that it is compliant with the conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., in step exS103, the conventional Decoding is performed using a video decoding method that complies with the standard.

In this way, by setting a new unique value to the stream type or video stream attribute information, when decoding, it is possible to check whether decoding is possible using the video decoding method or device shown in each of the above embodiments. can be judged. Therefore, even if multiplexed data conforming to different standards is input, it is possible to select an appropriate decoding method or device, so that decoding can be performed without causing errors. Further, the video encoding method or device or the video decoding method or device shown in this embodiment can be used in any of the devices and systems described above.

(Embodiment 8)
The video encoding method and device and the video decoding method and device shown in each of the above embodiments are typically implemented using an LSI, which is an integrated circuit. As an example, FIG. 47 shows the configuration of LSIex500 integrated into one chip. The LSI ex500 includes elements ex501, ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509 described below, and each element is connected via a bus ex510. The power supply circuit section ex505 is activated to an operable state by supplying power to each section when the power is on.

For example, when performing encoding processing, the LSI ex500 inputs AV signals from the microphone ex117, the camera ex113, etc. through the AV I/O ex509 based on the control of the control unit ex501 having the CPU ex502, the memory controller ex503, the stream controller ex504, the drive frequency control unit ex512, etc. The input AV signals are temporarily stored in an external memory ex511 such as an SDRAM. Based on the control of the control unit ex501, the stored data is divided into multiple times as appropriate depending on the processing amount and processing speed and sent to the signal processing unit ex507, where the audio signal is encoded and/or the video signal is encoded. Here, the video signal encoding process is the encoding process described in each of the above embodiments. The signal processing unit ex507 further performs processing such as multiplexing the encoded audio data and the encoded video data in some cases, and outputs the data to the outside from the stream I/O ex506. This output multiplexed data is transmitted to the base station ex107 or written to the recording medium ex215. In addition, when multiplexing, it is a good idea to temporarily store the data in buffer ex508 to ensure synchronization.

Note that although the memory ex511 has been described as a configuration outside the LSIex500, it may be included inside the LSIex500. The buffer ex508 is not limited to one, but may include a plurality of buffers. Further, the LSIex 500 may be formed into one chip or may be formed into multiple chips.

Further, in the above description, the control unit ex501 includes a CPU ex502, a memory controller ex503, a stream controller ex504, a drive frequency control unit ex512, etc., but the configuration of the control unit ex501 is not limited to this configuration. For example, the signal processing unit ex507 may further include a CPU. By providing a CPU inside the signal processing unit ex507, it is possible to further improve the processing speed. Further, as another example, the CPU ex502 may include a signal processing unit ex507 or a part of the signal processing unit ex507, such as an audio signal processing unit. In such a case, the control unit ex501 is configured to include a signal processing unit ex507 or a CPU ex502 having a part thereof.

Although it is referred to as an LSI here, it may also be called an IC, system LSI, super LSI, or ultra LSI depending on the degree of integration.

Further, the method of circuit integration is not limited to LSI, and may be implemented using a dedicated circuit or a general-purpose processor. An FPGA (Field Programmable Gate Array) that can be programmed after the LSI is manufactured or a reconfigurable processor that can reconfigure the connections and settings of circuit cells inside the LSI may be used. Such a programmable logic device typically performs the video encoding method or video encoding method described in each of the above embodiments by loading a program constituting software or firmware or reading it from a memory or the like. image decoding methods can be performed.

Furthermore, if an integrated circuit technology that replaces LSI emerges due to advancements in semiconductor technology or other derived technology, then of course the functional blocks may be integrated using that technology. Adaptation of biotechnology is a possibility.

(Embodiment 9)
When decoding video data generated by the video encoding method or device shown in each of the above embodiments, the amount of processing is expected to increase compared to when decoding video data conforming to conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. Therefore, in the LSI ex500, it is necessary to set a driving frequency higher than the driving frequency of the CPU ex502 when decoding video data conforming to conventional standards. However, when the driving frequency is increased, a problem occurs in that power consumption increases.

In order to solve this problem, moving image decoding devices such as TV EX300 and LSI EX500 are configured to identify which standard the video data conforms to and to switch the driving frequency according to the standard. FIG. 48 shows the configuration ex800 in this embodiment. The drive frequency switching unit ex803 sets the drive frequency to a high value when the video data is generated by the video encoding method or device shown in each of the above embodiments. Then, the decoding processing unit ex801 that executes the video decoding method shown in each of the above embodiments is instructed to decode the video data. On the other hand, when the video data is video data that complies with conventional standards, compared to when the video data is generated by the video encoding method or device shown in each of the above embodiments, Set the drive frequency low. Then, the decoding processing unit ex802, which conforms to the conventional standard, is instructed to decode the video data.

More specifically, the drive frequency switching section ex803 is composed of the CPU ex502 and the drive frequency control section ex512 shown in FIG. 47. Further, the decoding processing unit ex801 that executes the video decoding method shown in each of the above embodiments and the decoding processing unit ex802 that complies with the conventional standard correspond to the signal processing unit ex507 in FIG. 47. The CPUex 502 identifies which standard the video data conforms to. Then, based on the signal from the CPU ex502, the drive frequency control unit ex512 sets the drive frequency. Further, based on the signal from the CPUex502, the signal processing unit ex507 decodes the video data. Here, for example, the identification information described in Embodiment 7 may be used to identify the video data. The identification information is not limited to that described in Embodiment 7, and may be any information that can identify which standard the video data conforms to. For example, it is possible to identify which standard the video data complies with based on an external signal that identifies whether the video data is to be used for television or for a disc. In some cases, identification may be based on such external signals. Further, the selection of the driving frequency in the CPUex 502 may be performed based on, for example, a lookup table as shown in FIG. 50 in which video data standards and driving frequencies are associated with each other. A lookup table is stored in the buffer ex 508 or the internal memory of the LSI, and the CPU ex 502 can select the drive frequency by referring to this lookup table.

Figure 49 shows the steps of implementing the method of this embodiment. First, in step exS200, the signal processing unit ex507 acquires identification information from the multiplexed data. Next, in step exS201, the CPU ex502 identifies whether the video data was generated by the encoding method or device shown in each of the above embodiments based on the identification information. If the video data was generated by the encoding method or device shown in each of the above embodiments, in step exS202, the CPU ex502 sends a signal to the driving frequency control unit ex512 to set the driving frequency high. Then, the driving frequency control unit ex512 sets the driving frequency to a high frequency. On the other hand, if the video data indicates that it is video data that complies with conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, in step exS203, the CPU ex502 sends a signal to the driving frequency control unit ex512 to set the driving frequency low. Then, in the driving frequency control unit ex512, the driving frequency is set to a lower frequency than when the video data was generated by the encoding method or device shown in each of the above embodiments.

Furthermore, by changing the voltage applied to the LSIex500 or a device including the LSIex500 in conjunction with switching the drive frequency, it is possible to further enhance the power saving effect. For example, when setting the drive frequency low, it is conceivable to set the voltage applied to the LSIex 500 or the device including the LSIex 500 lower than when the drive frequency is set high.

The method of setting the drive frequency is not limited to the above-mentioned setting method; if the processing volume during decoding is large, the drive frequency is set high, and if the processing volume during decoding is small, the drive frequency is set low. For example, if the processing volume required to decode video data conforming to the MPEG4-AVC standard is larger than the processing volume required to decode video data generated by the video encoding method or device shown in each of the above embodiments, the drive frequency may be set in the opposite manner to that described above.

Furthermore, the method of setting the driving frequency is not limited to a configuration in which the driving frequency is lowered. For example, if the identification information indicates that the video data is generated by the video encoding method or device shown in each of the above embodiments, the voltage applied to the LSIex500 or the device including the LSIex500 is set high. However, if the video data indicates that it complies with conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., consider setting the voltage applied to LSIex500 or the device containing LSIex500 lower. It will be done. Further, as another example, if the identification information indicates that the video data is generated by the video encoding method or device shown in each of the above embodiments, driving of the CPU ex 502 is stopped. If the video data is compliant with conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., the CPU ex502 should be temporarily stopped because there is enough processing time. can also be considered. Even if the identification information indicates that the video data is generated by the video encoding method or device shown in each of the above embodiments, if there is enough processing time, the drive of the CPUex 502 may be temporarily stopped. It is also possible to stop it. In this case, it is conceivable to set the stop time to be shorter than when the video data indicates that the video data conforms to the conventional standards such as MPEG-2, MPEG4-AVC, and VC-1.

In this way, by switching the drive frequency according to the standard to which the video data conforms, it is possible to save power. Further, when a battery is used to drive the LSIex500 or a device including the LSIex500, it is possible to extend the life of the battery due to power saving.

(Embodiment 10)
In the above-mentioned devices and systems, such as televisions and mobile phones, multiple video data conforming to different standards may be input. In order to be able to decode multiple video data conforming to different standards, the signal processing unit ex507 of the LSI ex500 must support multiple standards. However, if the signal processing units ex507 corresponding to each standard are used individually, the circuit size of the LSI ex500 becomes large and the cost increases.

In order to solve this problem, we have developed a decoding processing unit for executing the video decoding method shown in each of the above embodiments, and a decoding unit that complies with conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. The configuration is such that a part of the processing unit is shared. An example of this configuration is shown in ex900 in FIG. 51A. For example, the video decoding method shown in each of the above embodiments and the video decoding method compliant with the MPEG4-AVC standard perform processing such as entropy encoding, dequantization, deblocking filter, motion compensation, etc. Some of the contents are common. For common processing content, the decoding processing unit ex902 compatible with the MPEG4-AVC standard is shared, and for other processing content specific to one aspect of the present invention that is not compatible with the MPEG4-AVC standard, a dedicated decoding processing unit is used. A possible configuration is to use ex901. In particular, since one aspect of the present invention is characterized by motion compensation, for example, a dedicated decoding processing unit ex901 is used for motion compensation, and other dequantization, entropy decoding, and deblocking filters are used. It is conceivable that the decoding processing unit may be shared for any or all of the processing. Regarding sharing of the decoding processing unit, for common processing contents, the decoding processing unit for executing the video decoding method shown in each of the above embodiments is shared, and processing contents specific to the MPEG4-AVC standard are shared. For this purpose, a dedicated decoding processing unit may be used.

Further, another example in which part of the processing is shared is shown in ex1000 of FIG. 51B. In this example, a dedicated decoding processing unit ex1001 corresponding to processing content specific to one aspect of the present invention, a dedicated decoding processing unit ex1002 corresponding to processing content specific to another conventional standard, and one embodiment of the present invention The configuration uses a shared decoding processing unit ex1003 that corresponds to processing contents common to the video decoding method according to the above and other conventional standard video decoding methods. Here, the dedicated decoding processing units ex1001 and ex1002 are not necessarily specialized for processing content specific to one aspect of the present invention or other conventional standards, but are capable of executing other general-purpose processing. Good too. Furthermore, it is also possible to implement the configuration of this embodiment using LSIex500.

In this way, by sharing the decoding processing unit for common processing contents between the moving image decoding method according to one aspect of the present invention and the moving image decoding method according to the conventional standard, the circuit scale of the LSI can be reduced. Moreover, it is possible to reduce costs.

The present invention is applicable to image processing devices, image capture devices, and image playback devices. Specifically, the present invention is applicable to digital still cameras, movie cameras, mobile phones with camera functions, smartphones, etc.

100 Image encoding device 101 Block division unit 102 Subtraction unit 103 Frequency conversion unit 104 Quantization unit 105 Entropy encoding unit 106, 202 Inverse quantization unit 107, 203 Inverse frequency conversion unit 108, 204 Addition unit 109, 205 Intra prediction unit 110, 206 Loop filter 111, 207 Frame memory 112, 208 Inter prediction unit 113, 209 Switching unit 121 Input image 122 Code block 123, 128, 224 Difference block 124, 125, 127, 222, 223 Coefficient block 126, 221 Bit stream 129, 225 Decoded blocks 130, 132, 134, 226, 229, 230 Prediction blocks 131, 227 Decoded images 133, 151, 228 Motion information 141 Coded information selection section 142 Motion estimation section 143 Motion compensation section 144 Motion information calculation section 161 Parallel movement flag 162 Rotation flag 163 Enlargement/reduction flag 164 Shear flag 171 Differential translation component 172 Differential rotation component 173 Differential enlargement/reduction component 174 Differential shear component 181 Encoding level information 200 Image decoding device 201 Entropy decoding unit

Claims (2)

a processing circuit;
and a storage device accessible from the processing circuit,
The processing circuit uses the storage device to
decoding from the bitstream information applied to a plurality of blocks included in the sequence and used to determine the number of parameters used for prediction in prediction based on affine transformation;
generating predicted images for each of the plurality of blocks by performing prediction based on affine transformation using a number of parameters selected by the information for each of the plurality of blocks included in the sequence;
Image decoding device. a processing circuit;
and a storage device accessible from the processing circuit,
The processing circuit uses the storage device to
In prediction based on affine transformation, determine the number of parameters used for prediction,
Generate a predicted image for each of the plurality of blocks by performing prediction based on affine transformation using the determined number of parameters for each of the plurality of blocks included in the sequence,
encoding information applied to the plurality of blocks included in the sequence and used to determine the number of parameters;
Image encoding device.

Images