JP7233027B2 - Image decoding device and image encoding device - Google Patents

Description

The present invention relates to image encoding methods and image decoding methods.

In the HEVC (High Efficiency Video Coding) standard, which is the latest video coding standard, various studies have been made to improve coding efficiency (see, for example, Non-Patent Document 1). This system is the conventional H.264 standard. The ITU-T (International Telecommunication Union Telecommunication Standardization Sector) standard denoted by H.26x and the ISO/IEC standard denoted by MPEG-x; H.264/AVC, or MPEG-4 AVC, was considered as the next video coding standard.

Japanese 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://phenix. int-evry. fr/jct/doc_end_user/documents/12_Geneva/wg11/JCTVC-L1003-v34. zip Taku Arakawa et al., "Acceleration of Motion Compensation Prediction Using Affine Transformation," Journal of Image Media Society: Image Information Media Vol. 51 No. 7, July 20, 1997, p. 1114-1117

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

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an image encoding method or an image decoding method capable of improving encoding efficiency.

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

Further, an image coding apparatus according to an aspect of the present invention includes a processing circuit and a storage device accessible from the processing circuit, and the processing circuit uses the storage device to perform prediction based on an affine transformation. , determining the number of parameters used for prediction, and performing prediction based on affine transformation using the determined number of parameters for each of a plurality of blocks included in a picture , thereby obtaining a prediction for each of the plurality of blocks. A predicted image is generated to encode information to be applied to the plurality of blocks in the picture, the information being used to determine the number of parameters.

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

INDUSTRIAL APPLICABILITY The present invention can provide an image encoding method or an image decoding method capable of improving encoding efficiency.

FIG. 1 is a block diagram showing the configuration of an image coding apparatus according to Embodiment 1. FIG. 2 is a flow chart showing processing operations of the image coding apparatus according to Embodiment 1. FIG. 3 is a flowchart illustrating an example of prediction block generation processing according to Embodiment 1. FIG. 4 is a block diagram showing an example of the configuration of an inter prediction unit according to Embodiment 1. FIG. 5 is a flowchart illustrating an example of inter prediction processing according to Embodiment 1. FIG. 6 is a diagram for explaining motion information using a non-parallel movement model in Embodiment 1. FIG. FIG. 7 is a flowchart showing an example of transform component selection processing for motion information according to the first embodiment. 8 is a flowchart illustrating an example of transform component selection processing using a motion component according to Embodiment 1. FIG. 9 is a flowchart illustrating an example of transform component selection processing using a predicted block size according to Embodiment 1. FIG. 10 is a flowchart illustrating an example of differential motion information calculation processing according to Embodiment 1. FIG. 11 is a flowchart illustrating an example of processing for calculating a difference translation component according to Embodiment 1. FIG. FIG. 12 is a flowchart illustrating an example of processing for calculating differential rotation components according to the first embodiment. 13 is a flowchart illustrating an example of processing for calculating a difference scaling component according to Embodiment 1. FIG. 14 is a flowchart illustrating an example of a differential shear component calculation process according to Embodiment 1. FIG. 15 is a diagram showing an example of motion information according to Embodiment 1. FIG. 16 is a diagram showing an example of motion information according to Embodiment 1. FIG. FIG. 17 is a diagram showing an example of code levels according to the second embodiment. 18 is a diagram showing an example of motion information according to Embodiment 2. FIG. 19 is a diagram showing an example of motion information according to Embodiment 2. FIG. 20 is a block diagram showing a configuration of an image decoding device according to Embodiment 4. FIG. 21 is a flowchart showing processing operations of the image decoding device according to Embodiment 4. FIG. 22 is a flowchart illustrating an example of motion information decoding processing according to Embodiment 4. FIG. 23 is a flowchart illustrating an example of decoding processing of differential motion information according to Embodiment 4. FIG. 24 is a flowchart illustrating an example of motion information generation processing according to Embodiment 4. FIG. FIG. 25 is a flowchart illustrating an example of parallel displacement component generation processing according to the fourth embodiment. FIG. 26 is a flowchart illustrating an example of rotation component generation processing according to the fourth embodiment. 27 is a flowchart illustrating an example of processing for generating an enlargement/reduction component according to Embodiment 4. FIG. FIG. 28 is a flowchart illustrating an example of shear component generation processing according to the fourth embodiment. 29 is a diagram for explaining intra prediction processing according to Embodiment 5. FIG. 30 is a diagram for explaining intra prediction processing according to Embodiment 5. FIG. FIG. 31 is a flow chart of an image coding method according to the embodiment. FIG. 32 is a flowchart of an image decoding method according to the embodiment. FIG. 33 is an overall configuration diagram of a content supply system that realizes a content distribution service. FIG. 34 is an overall configuration diagram of a digital broadcasting system. FIG. 35 is a block diagram showing a configuration example of a television. FIG. 36 is a block diagram showing a configuration example of an information reproducing/recording unit that reads and writes information on a recording medium that is an optical disc. FIG. 37 is a diagram showing a structural example of a recording medium, which is an optical disc. FIG. 38A is a diagram showing 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 the 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 the video stream is stored in the PES packet train. FIG. 42 is a diagram showing the structures of TS packets and source packets in multiplexed data. FIG. 43 is a diagram showing the data structure of the PMT. FIG. 44 is a diagram showing the internal configuration of multiplexed data information. FIG. 45 is a diagram showing the internal configuration of stream attribute information. FIG. 46 illustrates the steps of identifying video data. FIG. 47 is a block diagram showing a configuration example of an integrated circuit that implements the moving image encoding method and the moving image decoding method of each embodiment. FIG. 48 is a diagram showing a configuration for switching drive frequencies. FIG. 49 is a diagram showing the steps of identifying video data and switching drive frequencies. FIG. 50 is a diagram showing an example of a lookup table that associates video data standards with drive frequencies. FIG. 51A is a diagram showing an example of a configuration in which modules of a signal processing unit are shared. FIG. 51B is a diagram showing another example of a configuration for sharing modules of the signal processing unit.

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

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

On the other hand, a method of using high-order motion information such as affine transformation as motion information is also being studied. For example, the affine transformation can express three kinds of transformations, scaling, rotation, and shearing, in addition to translation, and can express transformations such as the rotation of the object described above. This improves the quality of the generated predicted image. Also, since the prediction unit can be increased, the coding efficiency can be improved.

However, while translation can be represented by two-dimensional information, affine transformation requires at least six-dimensional information to represent the above three types of transformations in addition to translation. Such an increase in the number of dimensions required for motion information causes a problem that the amount of motion information to be coded increases, and a problem that the amount of calculation required for estimating the motion information increases.

For such a problem, the prior art (Patent Document 1) discloses the following method. In each predictive block during encoding, estimation of motion information related only to translation and estimation of high-order motion information such as affine transformation are performed. Among these methods, a method that is judged to have higher coding efficiency is selected. A flag indicating whether motion information is translation or affine transformation and motion information corresponding to the flag are encoded. As a result, the amount of information can be reduced while taking advantage of the advantages of using high-order motion information, and the coding efficiency is improved. However, this method has a problem that the code amount when representing high-order motion information cannot be sufficiently reduced.

To address this problem, an image coding method according to an aspect of the present invention is an image coding method for coding an image, wherein a translation component is used as reference information indicating a reference destination of a current block to be coded. a selection step of selecting two or more transform components from a plurality of transform components including 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.

This allows the image coding method to select an arbitrary transform component from a plurality of transform components including translation and a plurality of non-translation. Therefore, the image coding method can improve coding efficiency in a coding scheme using high-order motion information.

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

For example, the selection information may include a flag corresponding to each of the plurality of transform components and indicating whether or not the corresponding transform component has been selected.

With this, the image coding method divides the affine matrix into a plurality of transform components, and can designate selection and non-selection for each of them, so that the amount of information can be reduced.

For example, in the selecting step, a set including some or all of the plurality of transform components, one coding level is selected from a plurality of coding levels representing sets different from each other, and the selected coding level and the selection information may indicate the selected coding level.

As a result, the image coding method can further reduce the amount of information. Also, the image coding method can reduce the processing load for selection.

For example, in the selection information encoding step, one selection information commonly used for an image including the current block may be encoded.

As a result, the image coding method can further reduce the amount of information. Also, the image coding method can reduce the processing load for selection.

For example, the selecting 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.

As a result, the image coding method can further reduce the amount of information.

For example, the plurality of non-translation components includes a rotation component, a scaling component and a shear component, and the selecting step does not select the shear component if the size of the current block is less than a first threshold. may

As a result, the image coding method can further reduce the processing load by limiting transform components that do not easily contribute to improvement in prediction accuracy.

For example, in the selecting step, the two or more transformation components may be selected with priority given to the translation component, the rotation component, the scaling component, and the shearing component in this order.

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

Further, an image decoding method according to an aspect of the present invention is an image decoding method for decoding a bitstream obtained by encoding an image, the image decoding method including a translation component and a plurality of non-translation components. a selection information decoding step of decoding selection information for specifying two or more transform components out of a plurality of transform components from the bitstream; and extracting the reference information of the current block from the bitstream using reference information of a decoded block different from the current block. 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 coding efficiency.

For example, the plurality of non-translational components may include four transform 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 plurality of transform components and indicating whether or not the corresponding transform component has been selected.

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

For example, in the selection information decoding step, one selection information commonly used for an image including the current block may be decoded.

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

For example, the plurality of non-translation components includes a rotation component, a scaling component and a shear component, and the selecting step selects the shear component if the size of the current block is less than or equal to a first threshold. It doesn't have to be.

For example, the plurality of non-translation components includes a rotation component, a scaling component and a shear component, and the selecting step prioritizes the translation component, the rotation component, the scaling component and the shear component in order. The two or more transform components may be selected.

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

This allows the image coding apparatus to select an arbitrary transform component from a plurality of transform components including translation and a plurality of non-translation. Therefore, the image coding apparatus can improve coding efficiency in a coding method using high-order motion information.

Further, an image decoding device according to an aspect of the present invention is an image decoding device that decodes a bitstream obtained by encoding an image, comprising: 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.

As a result, the image decoding device can decode a bitstream with improved coding efficiency.

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

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

It should be noted that each of the embodiments described below is a specific example of the present invention. Numerical values, shapes, materials, components, arrangement positions and connection forms of components, steps, order of steps, and the like shown in the following embodiments are examples and are not intended to limit the present invention. In addition, among the constituent elements in the following embodiments, constituent elements that are not described in independent claims representing the highest concept will be described as arbitrary constituent elements.

(Embodiment 1)
One embodiment of an image coding apparatus using the image coding method according to the present embodiment will be described. The image coding apparatus according to the present embodiment selects an arbitrary transform component from a plurality of transform components represented by affine transform, and generates a prediction image of the selected transform component using motion information. A bitstream is also generated that includes information indicative of the selected transform components. Thereby, the image coding apparatus can improve coding efficiency.

FIG. 1 is a block diagram of an image coding apparatus 100 according to this embodiment. The image coding device 100 includes a block dividing unit 101, a subtracting unit 102, a frequency transforming unit 103, a quantizing unit 104, an entropy coding unit 105, an inverse quantizing unit 106, an inverse frequency transforming unit 107, an adding unit 108, and intra prediction. A section 109 , a loop filter 110 , a frame memory 111 , an inter prediction section 112 and a switching section 113 are included.

The image coding apparatus 100 generates a bitstream 126 by coding the input image 121 .

FIG. 2 is a flowchart of encoding processing by the image encoding device 100 according to this embodiment.

First, the block division 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 encoding processing units (S101).

Next, the intra prediction unit 109 or the inter prediction unit 112 generates the prediction block 134 using the decoded block 129 or the decoded image 131 for each code block 122 (S102). The details of this process 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 transform unit 103 generates a coefficient block 124 by frequency transforming the difference block 123 . The quantization unit 104 generates a coefficient block 125 by quantizing the coefficient block 124 (S104).

Next, the entropy coding unit 105 generates a bitstream 126 by entropy-coding 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 inversely quantizes the coefficient block 125 to obtain a coefficient block 127. to generate The inverse frequency transform unit 107 restores the difference block 128 by inverse frequency transforming the coefficient block 127 (S106).

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

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

Note that the frequency transformation and quantization in step S104 and the inverse quantization and inverse frequency transformation in step S106 may be performed sequentially as separate processes, or may be performed collectively. Quantization is a process of digitizing values sampled at predetermined intervals in association with predetermined levels. Inverse quantization is a process of returning a value obtained by quantization to the original interval value. 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 coarse intervals into finer intervals of the original. In codec technology, quantization and dequantization are sometimes referred to as rounding, rounding, or scaling.

Next, the predicted block generation processing in step S102 will be described using FIG. FIG. 3 is a flow chart of prediction block generation processing (S102) according to the present embodiment.

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

If the prediction processing method is intra prediction ("intra prediction" in S121), the intra prediction unit 109 generates a prediction block 130 by intra prediction processing (S122). Also, 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). Also, the switching unit 113 outputs the generated prediction block 132 as a prediction block 134 .

Note that the image coding apparatus 100 does not perform step S121, but performs both steps S122 and S123, and performs the RD optimization model (formula 1 below) for each of the obtained prediction blocks. may be used to calculate the cost, and a method with a low cost, that is, a method with high coding efficiency may be selected.

In (Equation 1), D represents encoding distortion, for example, the sum of absolute differences between the original pixel values of the encoding target block and the generated prediction image. Also, R represents the amount of generated code, which is the amount of code necessary for encoding motion information for generating a predicted block, for example. Also, λ is a Lagrangian undetermined multiplier. This makes it possible to select an appropriate prediction mode from intra-prediction and inter-prediction, improving coding efficiency.

Next, the inter-prediction processing in step S123 will be described with reference to FIGS. 4 and 5. FIG.

FIG. 4 is a block diagram showing a configuration example of the inter prediction unit 112. As shown in FIG. The inter prediction unit 112 includes a coding 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 inter prediction processing (S123) according to the present embodiment.

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

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

Next, the motion compensation unit 143 performs motion compensation processing using the motion information 151 obtained in step S142 and the decoded image 131 to generate the prediction block 132 (S143).

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

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

Next, the selection of motion information transform components (S141) will be described in detail with reference to FIG. FIG. 7 is a flow chart of selection (S141) of transform components of motion information according to the present embodiment.

First, the encoding information selection unit 141 acquires an inter-image motion component between the input image (encoding block 122) and the decoded image 131 (S161). For example, the encoded information selection unit 141 extracts SIFT (Scale-Invariant Feature Transform) feature amounts of both the input image and the decoded image 131 . The encoding 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. Here, an example is shown in which the SIFT feature amount is used as the feature amount set as the motion component, but the present invention is not limited to this.

Next, the encoding information selection unit 141 selects transform components of motion information to be used for encoding according to the motion components acquired in step S161 (S162). Also, the encoding information selection unit 141 selects transform components of motion information to be used for encoding according to the size of the prediction block (S163). The process of step S141 ends with the series of processes described above.

Both steps S162 and S163 may be performed in this order, in the reverse order, in parallel, or only one of them may be performed. good.

In the present embodiment, "motion component" indicates a feature amount (motion between images) obtained by analyzing images using a predetermined analysis method, and "motion information" is based on the motion component. The description will be made assuming that the matrix, the vector, or the coefficients constituting them, which are determined by the encoding, are used for encoding.

The selection of the transform component using the motion component (step S162) and the selection of the transform component using the prediction block size (step S163) will be described in detail below.

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

First, the encoding information selection unit 141 extracts transformation components of translation, rotation, scaling, and shearing from motion components (S181).

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

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

If the translation components c and f are both 0, the motion information does not have a translation component; otherwise, the motion information has a translation component. If the enlargement ratio k is 1, there is no scaling component in the motion information, otherwise there is a scaling component in the motion information. If the rotation angle θ is 0, the motion information does not have a rotation component, and otherwise the motion information has a rotation component. If the shear angle φ is 0, there is no shear component in the motion information, otherwise there is a shear component in the motion information.

Here, an example is shown in which the threshold values of the translation components of translation, rotation, scaling, and shearing are (0, 0), 0, (1, 1), and 0, respectively, but the present invention is limited to this. isn't it. These thresholds may be values that take into consideration the features of the image, the precision of the imaging device, or the like. Alternatively, scaling may not be split into x and y directions, and the same magnification may be used in both x and y directions. As a result, the amount of code and the amount of processing can be reduced.

Thus, in step S181, the encoded information selection unit 141 extracts various transform components from the motion information. In addition, although the case where the motion information is indicated using the affine matrix has been described here, the motion information that can be used is not limited to this. Hereinafter, as for various conversion components, the rotation angle represents the rotation component, the enlargement factor represents the scaling component, the shear angle represents the shear component, and the translation vector represents the translation.

Subsequently, the encoding information selection unit 141 performs selection processing to determine whether to use parallel movement. First, in step S181, the encoding information selection unit 141 determines whether a translation component indicated by a motion vector or the like has been extracted from the motion component (S182).

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

Next, the encoding information selection unit 141 determines whether 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 is extracted from the motion component (S185).

If the motion component includes a rotation 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 encoding information selection unit 141 determines whether or not to use scaling. The encoding information selection unit 141 determines whether the scaling component indicated by the scaling factor k or the like is extracted from the motion component in step S181 (S188). If the motion component includes a scaling component (Yes in S188), the encoding information selection unit 141 selects scaling (S189). If there is no scaling component in the motion component (No in S188), the encoding information selection unit 141 does not select scaling (S190).

Finally, the encoding information selector 141 determines whether to use shear. The encoded information selection unit 141 determines whether the shear component indicated by the shear angle φ or the like is extracted from the motion component in step S181 (S191).

If the motion component includes a shear component (Yes in S191), the encoding information selection unit 141 selects shear (S192). If there is no shear component in the motion component (No in S191), the encoding information selection unit 141 does not select shear (S193). The process of step S162 is completed by the above series of processes.

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

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

First, the encoding information selection unit 141 determines whether to use translation. The encoding information selection unit 141 determines whether the block size obtained in step S201 is 4×4 blocks or less (S202).

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

Subsequently, the encoding information selection unit 141 determines whether to use rotation. The encoding information selection unit 141 determines whether the block size obtained in step S201 is 8×8 blocks or less (S205).

If the block size is larger than 8×8 blocks (No in S205), the encoding 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 encoding information selection unit 141 does not select rotation (S207).

Next, the encoding information selection unit 141 determines whether or not to use scaling. The encoding information selection unit 141 determines whether the block size obtained in step S201 is 16×16 blocks or less (S208). If the block size is larger than 16×16 blocks (No in S208), the encoding 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 encoding information selection unit 141 does not select scaling (S210).

Finally, the encoding information selector 141 determines whether to use shear. The encoding information selection unit 141 determines whether the block size obtained in step S201 is 32×32 blocks or less (S211).

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

Here, in steps S202, S205, S208, and S211, the case where 4×4, 8×8, 16×16, and 32×32 are used as an example of the block size threshold has been described. Any size is acceptable. Also, the encoding information selection unit 141 may switch the threshold according to the characteristics of the image. This can improve the coding efficiency.

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

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

Alternatively, the encoding 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 encoding information selection unit 141 may first determine whether or not there is a transform component in step S162, and compare block sizes (S163) only for transforms in which transform components exist.

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, according to the inventors' verification, it is difficult to contribute to the improvement of the prediction accuracy because the shear component has fewer effective images than the other transform components. Therefore, the priority of the shear component may be set lower than the other transform components. For example, the priority can be lowered by setting the order of determination processing after the determination processing of other components, or setting the threshold of block size larger than the threshold of other components.

In step S142 following step S141 shown in FIG. 5, the motion estimator 142 performs motion estimation on the transform 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 enlargement ratio by a constant value. Then, motion estimation section 142 determines, as 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.

The final step S144 will be described in detail with reference to FIGS. 10 to 14. FIG.

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

First, the motion information calculation unit 144 derives predicted 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 predicted motion information includes a translation component, a rotation component, a scaling component, and a shearing component, similar to the motion information. Various transform components included in the predicted motion information are hereinafter also referred to as predictive transform components. Also, the translation component, rotation component, scaling component, and shearing component included in the predicted motion information are also referred to as a predicted translational component, a predicted rotation component, a predicted scaling component, and a predicted shearing component.

For example, the motion information calculation unit 144 acquires, for each type of predictive transform component, a plurality of transform components of that type included in a plurality of motion information of a plurality of encoded blocks, and from the acquired transform components, A predictive transform component of the type is derived. For example, the motion information calculation unit 144 derives an average value of transform components of each of a plurality of encoded blocks that refer to the same reference picture as predictive transform components. In addition, as a method of deriving the predictive transformation component, all calculation methods used in HEVC or the like can be applied.

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

FIG. 11 is a flow chart of the calculation processing (S222) of the difference translation component.

First, the motion information calculation unit 144 determines whether or not the motion information 151 estimated in step S142 includes a translation component (S241). For example, the motion information calculation unit 144 determines that the translation component does not exist when both the x-direction and y-direction components included in the translation component are zero, and determines that at least one of the x-direction and y-direction components is not zero, it is determined that there is a translation component. Note that the motion information calculation unit 144 may determine that the translation component does not exist when the magnitude of the translation component is smaller than a predetermined value. Also, the motion information calculation unit 144 may switch the predetermined value according to the feature of the image. Further, the motion information calculation unit 144 may determine that the parallel movement component always exists (or the parallel movement component does not always exist) when the feature of the image satisfies 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 the parallel movement is not selected.

If the motion information 151 does not include a parallel movement component (No in S241), the motion information calculation unit 144 sets the parallel movement flag indicating that "a parallel movement exists" to OFF, and sets the parallel movement flag to OFF. is added to the motion information 133 to be converted (S242).

If the motion information 151 includes a parallel movement component (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 or not the predicted motion information derived in step S221 includes a translation component (S244). If the predicted motion information does not include a parallel movement component (No in S244), the motion information calculation unit 144 sets the predicted parallel movement component to 0 (S245).

On the other hand, if the predicted motion information includes a parallel movement component (Yes in S244), the motion information calculation unit 144 sets the parallel movement component of the predicted motion information as the predicted parallel movement 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 difference 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 rotation component (S223).

FIG. 12 is a flow chart of the differential rotation component calculation process (S223).

First, the motion information calculation unit 144 determines whether or not the motion information 151 estimated in step S142 includes a rotation component (S261). For example, the motion information calculation unit 144 may determine whether or not the rotation component is zero in the same manner as the translation determination (S241), or may compare the magnitude of the rotation angle with a predetermined value. . Also, the motion information calculation unit 144 may switch the predetermined value according to the features of the image. For example, the motion information calculation unit 144 always determines that a rotation component exists if the image has a feature that rotation is likely to contribute to improving the prediction accuracy, and otherwise determines that the rotation component does not exist. You may If it is determined to always exist, 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 the motion information 151 does not include a rotation component (No in S261), the motion information calculation unit 144 sets the rotation flag indicating that "there is rotation" to OFF, and sets the rotation flag to OFF. It is added to the information 133 (S262).

If the motion information 151 includes a rotation component (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 or not the predicted motion information acquired in step S221 includes a rotation component (S264).

If no rotation component exists in the predicted motion information (No in S264), the motion information calculation unit 144 sets the predicted rotation component to 0 (S265). If the predicted motion information includes a rotation component (Yes in S264), the motion information calculation unit 144 sets the rotation component of the predicted motion information as the predicted rotation 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. It is added to the motion information 133 (S267).

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

FIG. 13 is a flow chart of the difference scaling component calculation processing (S224).

First, the motion information calculation unit 144 determines whether or not the motion information 151 estimated in step S142 includes a scaling component (S281). For example, the motion information calculation unit 144 may determine whether the scaling component is zero (value is 1) in the same manner as in step S241 or S261, or compare the size of the scaling component with a predetermined value. You may Also, the motion information calculation unit 144 may switch the predetermined value according to the features of the image. For example, the motion information calculation unit 144 may set a predetermined value based on the time change of the angle of view in the case of an image when zoomed in or zoomed out.

In addition, the motion information calculation unit 144 always determines that a scaling component exists if the image has characteristics that the scaling component is likely to greatly contribute to prediction accuracy. You can decide not to. For example, the motion information calculation unit 144 may determine that the scaling component always exists when the input image 121 is an image obtained by zooming in or zooming out. If it is determined to always exist, 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. is added to the motion information 133 to be converted (S282).

If the motion information 151 includes a scaling component (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 or not the predicted motion information acquired in step S221 includes 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 the predicted motion information includes a scaling component (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 differential 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. 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).

FIG. 14 is a flow chart of the differential shear component calculation process (S225).

First, the motion information calculation unit 144 determines whether or not the motion information 151 estimated in step S142 includes a shear component (S301). For example, the motion information calculation unit 144 may determine whether the shear component is zero, or may compare the magnitude of the shear component with a predetermined value, as in steps S241, S261, or S281. . Also, the motion information calculation unit 144 may switch the predetermined value according to the features of the image. Further, the motion information calculation unit 144 may determine that the shear component always exists (or the shear 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 shear component when it is determined in step S193 of FIG. 8 or step S213 of FIG. 9 that shear is not selected.

When no shear component exists 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. It is added to the information 133 (S302).

If the motion information 151 includes a shear component (Yes in S301), the motion information calculation unit 144 sets the shear flag to ON and adds 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 no shear component exists in the predicted motion information (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. It is added to the motion information 133 (S307).

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

Note that the processing order of steps S222 to S225 is not limited to this order and may be arbitrary. Moreover, some or all of these processes may be performed in parallel. Further, as described above, when 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 only processes the permitted transform components. may

15 and 16 are diagrams showing an example of the encoded motion information 133. FIG. As shown in FIG. 15, the motion information 133 includes a translation flag 161, a rotation flag 162, a scaling flag 163, a shearing flag 164, a differential translation component 171, a differential rotation component 172, and a differential scaling. It includes a component 173 and a differential shear component 174 . The meaning of each piece of information is as described above.

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

(effect)
As described above, the image coding apparatus 100 according to the present embodiment selects only necessary transform components by using image features, etc., and information indicating the selected transform components (parallel movement flag, rotation flag, enlargement (shrink flag and shear flag) and the selected transform components. As a result, the image coding apparatus 100 can selectively use only valid transform components, and can improve coding efficiency. In this way, the image coding apparatus 100 can flexibly select various transforms and reduce the motion information necessary for generating a predicted image, thereby improving coding efficiency.

In addition, the image coding apparatus 100 selects transform components using an estimation result of the type of transform present in the image being encoded, the size of the prediction block, or the like. As a result, the image coding apparatus 100 can limit the types of motion information to be searched for during prediction processing, so that the speed of processing can be increased.

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 to be used are not limited to these.

For example, instead of the 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 coding efficiency.

In other words, the image coding apparatus 100 according to the present embodiment only needs to divide a motion component into a plurality of transform components and determine whether or not each transform component is used. That is, the image coding apparatus 100 may use matrices or transforms other than those described above, or may divide motion information into transform components different from those described above.

In addition, in the above description, an example is shown in which flags are added to each transform component in units of blocks during inter prediction in steps S242, S243, S261, S263, S282, S283, S302, and S303. may be specified per image, per sequence, or per region into which an image is divided. For example, this area is an area obtained by dividing the image into four parts. By this means, all blocks included in an image or sequence specified in advance before performing inter prediction are encoded using the same type of transform component. Therefore, it is possible to omit the determination process for each block, so that the encoding efficiency can be further improved. Also, since the number of flags in the bitstream can be reduced, the coding efficiency can be further improved.

In addition, when various transform components do not exist in the predicted motion information, 0, 0, 1, and 0 are substituted as predictive transform components in steps S245, S265, S285, and S305, respectively. is not limited to this. For example, when the entire screen is rotated, an angle determined according to the features of the image may be substituted as the predicted rotation component. Furthermore, even if the process of substituting a predetermined angle such as 0 into the predictive transform component and the process of substituting the angle determined according to the feature of the image into the predictive transform component are switched according to a predetermined condition. good. In this way, motion information contains transform components, but predictive motion information does not contain such transform components. By performing prediction while switching substitute values, it is possible to reduce the value of differential motion information. is. This makes it possible to further improve the coding efficiency.

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

In this embodiment, instead of the processes of steps S162 and S163 described above, for example, the following processes are performed.

FIG. 17 is a diagram showing an example of the relationship between code levels and transform components. For example, as shown in FIG. 17, encoding level 1 includes translation, encoding level 2 includes rotation and scaling, and encoding level 3 includes shear.

The coding information selection unit 141 selects a coding level according to conditions such as image features or a permissible bandwidth.

Next, the coding information selection unit 141 selects transform components included in coding levels below the selected coding level. For example, for coding level 2, the three transform components of translation, rotation, and scaling included in coding level 2 and coding level 1 are selected.

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

18 and 19 are diagrams showing an example of the encoded motion information 133. FIG. As shown in FIG. 18 , the motion information 133 includes encoding level information 181 , differential translation component 171 , differential rotation component 172 , differential scaling component 173 and differential shear component 174 .

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

As described above, according to the present embodiment, the amount of information required for encoding can be further reduced, so that the encoding efficiency can be improved. Although an example using various conversion levels has been described here, the present invention is not limited to this, and information indicating a combination of conversion components may be used. For example, in the above description, an example in which all transform components included in the selected level and below are specified has been described, but the following information may also be used. For example, at level 0 no transform components are used, at level 1 translation only is used, at level 2 translation and rotation are used, at level 3 translation and scaling are used, at level 4 if level 5 then translation, rotation and scaling are used, if level 6 then translation and shear are used, if level 7 then translation, rotation, scaling and shear are used good too. In this way, a combination of transform components may be specified for each level, and transform components associated with each level may be selected.

(Embodiment 3)
As a result of verification by the inventors, it was found that among translation, rotation, scaling, and shearing, shearing is less likely to contribute to an improvement in prediction accuracy than other transformations. Therefore, in the present embodiment, an example in which priority is given to a plurality of transform components will be described.

As a first method of giving priority to 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 higher than other transformations that can greatly improve the prediction accuracy, such as rotation. As a result, when the block size is small, it is possible to limit the use of transform components that make it difficult to improve the prediction accuracy, so that it is possible to prevent the coding efficiency from deteriorating. Similarly, scaling does not contribute much to improving prediction accuracy with small block sizes, so a larger threshold is set than for translation and rotation.

When the inventors conducted verification using a general moving image, it was found that the order of translation, rotation, scaling, and shearing tends to improve the prediction accuracy, although the order differs depending on the characteristics of the image. Therefore, the priority is set in this order. This makes it possible to limit the selection of transform components with low priority according to the state of image features, size, band, or the like.

A second method of giving priority to a plurality of transform components will be described below. An example of a method for limiting shear is described herein.

First, a brief description will be given of how to set coefficients for affine transformation. As described in Non-Patent Document 2, by setting an 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 are set. That is, the coefficient (motion information) that minimizes the evaluation function E(a) is derived.

If the shear is constrained, the orthogonality of the x and y axes is preserved before and after the affine transformation. That is, the coefficients of the affine transformation shown in (Formula 2) above must satisfy the constraint conditions of (Formula 4) below.

Therefore, a constraint is added to the evaluation function of (Formula 3) as shown in (Formula 5) below. Due to this constraint, the value of the evaluation function E(a) increases as the shear component increases, making it difficult to select coefficients that include a shear component. This method is called the penalty method. Also, increasing the positive constant μ increases the influence of the constraint. By obtaining the coefficient of the affine matrix that minimizes the evaluation function E(a) of the following (Formula 5) in this way, it is possible to calculate the coefficient with the shear component limited.

The inventors solved the minimization problem by setting a small μ, set the optimum solution at that point in the result of repeating the search a certain number of times as a new initial value, and solved the minimization problem again with a large value of μ. The coefficient was calculated by repeating the process of solving until μ reached a predetermined size. Note that the method for obtaining the coefficient is not limited to this method.

Also, although the method of limiting shearing (lowering the priority) has been described here, a similar technique can be applied to other transformations.

(Other modifications)
In Embodiments 1 to 3 above, the 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, HEVC has a motion estimation 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. Even in such a case, as in Embodiments 1 to 3, the image coding apparatus selects one or more transform components from a plurality of transform components and generates a predicted image using the selected transform components. may Also, the image coding apparatus may code information (the flag or coding level information) indicating the selected (used) transform component.

For example, the image coding apparatus encodes the selected transform components based on whether or not there are various transform components in prediction information predicted from motion information of blocks spatially or temporally adjacent to the current block. become In this case, the image coding apparatus may use the average value of the rotation components as the rotation component of the current block when all motion information of a plurality of adjacent blocks includes rotation components. Also, the image coding apparatus determines that the rotation component is not used for the current block when only one piece of motion information of a plurality of adjacent blocks contains a rotation component and the rotation component is less than a predetermined value. good too. Alternatively, the image coding apparatus may set the rotation components of other adjacent blocks to zero, calculate the average value of the plurality of 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 modifications thereof may be applied to the present embodiment.

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

FIG. 20 is a block diagram of the image decoding device 200 according to this embodiment. The image decoding device 200 includes an entropy decoding unit 201, an inverse quantization unit 202, an inverse frequency transform unit 203, an addition unit 204, an intra prediction unit 205, a loop filter 206, a frame memory 207, an inter prediction unit 208, and a switching unit 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 the motion information 228 from the bitstream 221 obtained by encoding a still image or moving image including one or more pictures (S401). Also, the entropy decoding unit 201 decodes the coefficient block 222 from the bitstream 221 (S402).

The inverse quantization unit 202 generates a coefficient block 223 by inversely quantizing the coefficient block 222 . The inverse frequency transform unit 203 restores the difference block 224 by inverse frequency transforming the coefficient block 223 (S403).

Next, the intra prediction unit 205 or the inter prediction unit 208 generates the prediction block 230 using the motion information 228 decoded in step S401 and the decoded block (S404). Specifically, the intra prediction unit 205 generates a prediction block 226 by intra prediction processing. The inter prediction unit 208 generates a prediction block 229 by inter prediction processing. Switching section 209 outputs one of prediction blocks 226 and 229 as prediction block 230 .

Next, the adder 204 adds the difference block 224 and the prediction block 230 to generate the decoded block 225 (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 bitstream 221 have been decoded (S406). For example, the image decoding device 200 makes this determination depending on whether the input bitstream 221 has ended. If the decoding of all blocks has not been completed (No in S406), the processing from step S401 onward is performed for the next block. When all blocks included in the bitstream 221 have been decoded (Yes in S406), the loop filter 206 combines all decoded blocks and performs loop filter processing to generate a decoded image 227 (reconstructed image). (S407). The frame memory 207 stores the decoded image 227. FIG. This decoded image 227 is used for inter prediction processing by the inter prediction unit 208 .

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

Next, motion information decoding processing (S401) will be described using FIG. FIG. 22 is a flowchart of motion information decoding processing (S401) according to this embodiment.

First, the entropy decoding unit 201 decodes differential motion information from the bitstream 221 (S421). The entropy decoding unit 201 also decodes information for deriving predicted motion information (S422). 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 difference motion information acquired in step S421 (S423 ).

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

The decoding process of differential motion information (S421) will be described using FIG. 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 translation flag indicating whether translation exists (indicating whether the motion information 228 includes a differential translation component) from the bitstream 221 (S441). The configuration of the motion information 228 and the meanings of 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 uses the translation flag to determine whether translation exists (S442).

If the translation flag indicates that translation exists (Yes in S442), the entropy decoding unit 201 decodes the differential translation component from the bitstream 221 (S443). If the translation flag indicates that there is no translation (No in S442), the entropy decoding unit 201 does not decode the differential translation component and performs the next processing step (S444).

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 there is rotation (indicating whether the motion information 228 contains a differential rotation component) 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 difference scaling component (S447 to S449). The entropy decoding unit 201 decodes from the bitstream 221 an expansion/reduction flag indicating whether there is expansion/reduction (indicating whether the motion information 228 contains a difference expansion/reduction component) (S447). The entropy decoding unit 201 uses the scaling flag to determine whether there is scaling (S448).

If the scaling flag indicates that there is scaling (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 decoding processing of differential shear components (S450 to S452). The entropy decoding unit 201 decodes a shear flag indicating whether a shear component exists (indicating whether the motion information 228 includes a differential shear component) from the bitstream 221 (S450). The entropy decoding unit 201 uses the shear flag to determine whether a shear component exists (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, motion information generation processing (S423) will be described with reference to FIGS. 24 to 28. FIG.

FIG. 24 is a flowchart of motion information generation processing (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 uses the acquired motion information to derive predicted motion information ( S461).

First, the inter prediction unit 208 generates translation components from the difference motion information and the predicted motion information (S462). FIG. 25 is a flow chart of the parallel movement component generation processing (S462).

First, the inter prediction unit 208 determines whether or not the difference translation component is acquired in step S421 (S481).

If a difference translation component has been acquired (Yes in S481), the inter prediction unit 208 determines whether a translation 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 parallel movement component (Yes in S482), the inter prediction unit 208 sets the parallel movement component of the predicted motion information as the predicted parallel movement component (S484).

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

If there is no differential translation component (No in S482), the inter prediction unit 208 terminates the processing related to the translation component (S462).

Next, the inter prediction unit 208 generates rotation components from the differential motion information and the predicted motion information (S463). FIG. 26 is a flow chart of this rotational component generation processing (S463).

First, the inter prediction unit 208 determines whether or not the differential rotation component is 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 there is no rotation in the predicted motion information (No in S502), the inter prediction unit 208 sets the predicted rotation component to 0 (S503). If the predicted motion information includes a rotation component (Yes in S502), the inter prediction unit 208 sets the rotation component of the predicted motion information as the predicted rotation 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 differential rotation component (S505).

If there is no differential rotation component (No in S501), the inter prediction unit 208 terminates the processing related to the rotation component (S463).

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

First, the inter prediction unit 208 determines whether or not the difference scaling component is acquired in step S421 (S521).

If a difference 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 there is no scaling in the predicted motion information (No in S522), the inter prediction unit 208 sets the predicted scaling component to 1 (S523). If the predicted motion information includes a scaling component (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 differential scaling component (S525).

If the difference scaling component does not exist (No in S521), the inter prediction unit 208 terminates the processing related to scaling components (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 the shear component generation process (S465).

First, the inter prediction unit 208 determines whether the differential shear component is acquired 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 exists in the predicted motion information acquired in step S461 (S542).

If there is no shear 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 differential shear component (S545).

If there is no differential shear component (No in S541), the inter prediction unit 208 terminates the shear component processing (S465).

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

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 obtained by dividing an image. When a flag is provided in units other than block units 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. decryption process. As a result, the image decoding apparatus can omit the determination step and the like, and can perform decoding with high prediction accuracy with a small amount of information and a small processing load.

Also, as in the first embodiment, the order of the various transform component generation processes (S462 to S465) is not limited to the order shown in FIG. Also, part or all of the processing of steps S462 to S465 may be performed in parallel. Alternatively, superiority or inferiority may be set for these processes, and the processes may be performed in descending order of priority.

Also, as in Embodiment 2, when coding level information indicating the coding level is used instead of various flags, the image decoding apparatus 200 uses the coding level information as bits instead of the various flags described above. Decode from stream 221 . Also, the image decoding apparatus uses information indicated by the coding level information instead of various flags to determine the presence or absence of transform components.

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

(effect)
As described above, the image decoding apparatus 200 according to the present embodiment can decode the bitstream 221 in which only the transform components necessary for generating the prediction 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 that images with higher image quality can be reproduced.

In this embodiment, an example in which translation, rotation, scaling, and shearing are included in the motion information as transformation components has been described, but transformations that can be used are not limited to these. For example, a trapezoid transform may be used. As a result, complex transforms can be expressed, so the image decoding device can generate a more highly accurate predicted image.

In other words, the image decoding apparatus 200 according to the present embodiment only needs to divide motion information into a plurality of transform components and determine whether or not to decode each transform component. That is, the image decoding device 200 may use transform components other than the above.

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

(Embodiment 5)
In Embodiments 1 to 4 above, examples of using affine transformation for inter prediction have been described, but in this embodiment, an example of using affine transformation for intra prediction will be described.

The image coding device (or image decoding device) according to the present embodiment, as shown in FIG. 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, not only translation but also various transformations such as rotation, enlargement/reduction, shearing, etc. are used in this copying.

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

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

In intra prediction, among rotation, scaling, and shearing, the order of scaling, rotation, and shearing tends to contribute to improvement in prediction accuracy. Therefore, it is preferable to give priority in this order. Note that the method described in Embodiment 3 can be used as the method of assigning priority to a plurality of conversions.

Also, the priority may be changed according to the type of image. For example, in a natural image, priority may be given in the order of scaling, rotation, and shearing, and in screen content such as map information, priority may be given in the order of rotation, scaling, and shearing.

As described above in Embodiments 1 to 3 and 5, the image coding device according to the embodiment is an image coding device that performs image coding, and performs the processing shown in FIG.

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

Next, the image coding 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 transform components selected from among the plurality of transform components (S604). For example, the selection information includes flags (translation flag, rotation flag, scale flag, and shear flag) corresponding to each of the plurality of transform components and indicating whether or not the corresponding transform component has been selected. Alternatively, the selection information is a set including some or all of a plurality of transform components and indicates one coding level from a plurality of coding levels indicating mutually different sets. In this case, in step S601, two or more transform components included in the set indicated by the coding level indicated by the selection information are selected.

Further, the image coding apparatus may encode the selection information for each block, for each picture, for each sequence, or for each region into which a picture is divided. may be encoded. That is, the image coding apparatus may encode one piece of selection information commonly used for an image including the current block, or code one piece of selection information commonly used for a sequence including the current block. Alternatively, one selection information commonly used for the area including the current block may be encoded.

Next, the image coding apparatus codes the reference information of the current block using the reference information of the coded block different from the current block (S605). For example, an image coding apparatus codes differential reference information, which is the difference between the reference information of the coded block and the reference information of the current block.

Note that in step S601, the image coding apparatus may select two or more transform components according to 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 largest coding unit (CU) and information indicating whether to further divide each coding unit.

Also, 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.

Also, in step S601, the image coding apparatus may select two or more transform components with priority given in the order of translation component, rotation component, scaling component, and shear component. For example, priority can be set using the method described in the third embodiment.

Also, 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, from the bitstream, selection information for specifying two or more transform components among a plurality of transform components including a translation component and a plurality of non-translation components (S611). Here, the multiple non-translation components include, for example, a rotation component, a scaling component and a shear component. The selection information also includes, for example, flags (parallel movement flag, rotation flag, scaling flag, and shearing flag) corresponding to each of the plurality of transform components and indicating whether or not the corresponding transform component has been selected. Alternatively, the selection information is a set including some or all of a plurality of transform components and indicates one coding level from a plurality of coding levels indicating mutually different sets.

Further, the image decoding device may decode the selection information for each block, for each picture, for each sequence, or for each region obtained by dividing a picture. You may That is, the image decoding device may decode one piece of selection information commonly used for an image including the current block, or decode one piece of selection information commonly used for a sequence including the current block. Alternatively, one selection information commonly used for the area including the current block may be decoded.

Also, 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 motion information in inter prediction or information indicating a processed block as a reference destination in intra prediction. Note that when the selection information indicates the 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 the reference information of the decoded block different from the current block (S613). Specifically, the image decoding device decodes the differential 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 transform 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).

The selection information may indicate the size of the current block, and in step S612, the image decoding device may select two or more transform components according to the size of the current block. For example, the selection information includes information indicating the size of the largest coding unit (CU) and information indicating whether to further divide each coding unit. The image decoding device uses this information to determine the current block size.

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

Also, in step S612, the image coding apparatus may select two or more transform components with priority given in the order of translation component, rotation component, scaling component, and shear component. For example, priority can be set using the method described in the third embodiment.

Although the image coding method and the image decoding method according to the embodiments have been described above, the present invention is not limited to these embodiments.

Each processing unit included in the image encoding device and the image decoding device according to the above embodiments is typically implemented as an LSI, which is an integrated circuit. These may be made into one chip individually, or may be made into one chip so as to include part or all of them.

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

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

In other words, the image encoding device and the image decoding device comprise a processing circuit and a storage electrically connected to the processing circuit (accessible from the control circuit). The processing circuitry includes at least one of dedicated hardware and program execution. Also, if the processing circuit includes a program execution unit, the storage device stores a software program executed by the program execution unit. The processing circuit uses the storage device to execute the encoding method or the decoding method according to the above embodiments.

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

In addition, the numbers used above are all examples for specifically describing the present invention, and the present invention is not limited to the illustrated numbers.

Also, the division of functional blocks in the block diagram is an example, and a plurality of functional blocks can be realized as one functional block, one functional block can be divided into a plurality of functional blocks, and some functions can be moved to other functional blocks. may Moreover, single hardware or software may process the functions of a plurality of functional blocks having similar functions in parallel or in a time-sharing manner.

Also, the order in which the steps included in the above encoding method or decoding method are executed is for illustrative purposes in order to specifically describe the present invention, and orders other than the above may be used. Also, some of the above steps may be executed concurrently (in parallel) with other steps.

Although the encoding device and decoding device according to one or more aspects of the present invention have been described above based on the embodiments, the present invention is not limited to these embodiments. As long as it does not depart from the spirit of the present invention, one or more modifications of the present embodiment that can be conceived by a person skilled in the art, or a form constructed by combining the components of different embodiments may be included within the scope of the embodiments.

(Embodiment 6)
By recording on a storage medium a program for realizing the configuration of the video encoding method (image encoding method) or the video decoding method (image decoding method) shown in each of the above embodiments, each of the above implementations can be easily implemented in an independent computer system. The storage medium may be a magnetic disk, an optical disk, a magneto-optical disk, an IC card, a semiconductor memory, etc., as long as the program can be recorded thereon.

Further, application examples of the moving image encoding method (image encoding method) and the moving image decoding method (image decoding method) shown in the above embodiments and a system using them will be described. The system is characterized by having an image encoding/decoding device comprising an image encoding device using an image encoding method and an image decoding device using an image decoding method. Other configurations in the system may be appropriately changed from case to case.

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

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

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

The camera ex113 is a device such as a digital video camera capable of capturing moving images, and the camera ex116 is a device such as a digital camera capable of capturing still images and moving images. In addition, the mobile phone ex114 is a GSM (registered trademark) (Global System for Mobile Communications) system, CDMA (Code Division Multiple Access) system, W-CDMA (Wideband-Code Division Multiple Access) system, or LTE (Long Term Evolution) The system may be a mobile phone of HSPA (High Speed Packet Access), PHS (Personal Handyphone System), or the like.

In the content supply system ex100, the camera ex113 and the like are connected to the streaming server ex103 through the base station ex109 and the telephone network ex104, thereby enabling live distribution and the like. In the live distribution, the content captured by the user using the camera ex113 (for example, live music video) is encoded as described in each of the above embodiments (that is, in one aspect of the present invention, the encoding process is performed). functions as the image encoding device) and transmits to the streaming server ex103. On the other hand, the streaming server ex103 stream-distributes the transmitted content data to the requesting client. Clients include a computer ex111, a PDA ex112, a camera ex113, a mobile phone ex114, a game machine ex115, etc., which can decode the encoded data. Each device that has received the distributed data decodes and reproduces the received data (that is, functions as an image decoding device according to an aspect of the present invention).

It should be noted that the encoding processing of the photographed data may be performed by the camera ex113, the streaming server ex103 that performs data transmission processing, or may be performed by mutual sharing. Similarly, the decryption processing of the distributed data may be performed by the client, by the streaming server ex103, or may be shared by each other. In addition, still image and/or moving image data captured by the camera ex116, not limited to the camera ex113, may be transmitted to the streaming server ex103 via the computer ex111. The encoding process in this case may be performed by any one of the camera ex116, the computer ex111, and the streaming server ex103, or may be shared among them.

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

Also, the streaming server ex103 may be a plurality of servers or a plurality of computers, and may distribute and process, record, and distribute data.

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 the information transmitted by the user in real time, and even users without special rights or facilities can realize personal broadcasting.

Note that not only the content supply system ex100 but also the digital broadcasting system ex200 as shown in FIG. device (image decoding device) can be incorporated. 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 the image encoding device according to one aspect of the present invention). The broadcasting satellite ex202 receiving this transmits a radio wave for broadcasting, and the home antenna ex204 capable of receiving the satellite broadcast receives this radio wave. 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 an aspect of the present invention).

In addition, a reader/recorder ex218 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 moving image decoding device or the moving image 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 another device or system by the recording medium ex215 on which the multiplexed data is recorded. Also, the moving image decoding device may be installed in a set-top box ex217 connected to a cable television cable ex203 or a satellite/terrestrial broadcasting antenna ex204, and displayed on a television monitor ex219. At this time, the video decoding device may be incorporated in the television instead of the set-top box.

FIG. 35 is a diagram showing a television (receiver) ex300 using the moving image decoding method and moving image encoding method described in each of the above embodiments. The TV ex300 acquires 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 outputs the received multiplexed data. Alternatively, a modulation/demodulation unit ex302 that modulates the 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 the signal processing unit ex306. A multiplexing/demultiplexing unit ex303 for multiplexing 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 an aspect of the present invention or an image function as a decoding device), a speaker ex307 that outputs a decoded audio signal, and an output unit ex309 that has a display unit ex308 such as a display that displays the decoded video signal. Furthermore, the television ex300 has an interface section ex317 having an operation input section ex312 and the like that receives user operation input. Furthermore, the television ex300 has a control unit ex310 that controls each unit in an integrated manner, and a power supply circuit unit ex311 that supplies power to each unit. In addition to the operation input unit ex312, the interface unit ex317 includes a bridge ex313 that is connected to an external device such as a reader/recorder ex218, a slot unit ex314 that enables mounting of a recording medium ex216 such as an SD card, and an external recording unit such as a hard disk. It may have a driver ex315 for connecting to media, a modem ex316 for connecting to a telephone network, and the like. The recording medium ex216 can electrically record information by storing non-volatile/volatile semiconductor memory elements. Each part of the television ex300 is connected to each other via a synchronous bus.

First, a configuration will be described in which the television ex300 decodes and reproduces multiplexed data acquired from the outside via the antenna ex204 or the like. The television ex300 receives a user operation from the remote controller ex220 or the like, and demultiplexes the multiplexed data demodulated by the modulation/demodulation unit ex302 by the multiplexing/demultiplexing unit ex303 based on the control of the control unit ex310 having a CPU or the like. Furthermore, the television ex300 decodes the separated audio data in the audio signal processing unit ex304, and decodes the separated video data in the video signal processing unit ex305 using the decoding method described in each of the above embodiments. The decoded audio signal and video signal are respectively output from the output unit ex309 to the outside. When outputting, these signals should be temporarily accumulated in the buffers ex318, ex319, etc. so that the audio signal and the video signal can be reproduced in synchronization. Also, the television ex300 may read the multiplexed data from recording media ex215 and ex216 such as a magnetic/optical disk and an SD card instead of broadcasting. Next, a configuration will be described in which the television ex300 encodes an audio signal or a video signal and transmits it to the outside or writes it to a recording medium or the like. The television ex300 receives a user operation from the remote controller ex220 or the like, encodes an audio signal with an audio signal processing unit ex304, and converts a video signal with a video signal processing unit ex305 based on the control of the control unit ex310. Encode using the encoding method described in . The encoded audio and video signals are multiplexed by the multiplexer/demultiplexer ex303 and output to the outside. When multiplexing, these signals should be temporarily accumulated in buffers ex320, ex321, etc. so that the audio signal and the video signal are synchronized. A plurality of buffers ex318, ex319, ex320, and ex321 may be provided as shown in the figure, or one or more buffers may be shared. Furthermore, data may be stored in buffers other than those shown in the figure, for example, between the modulation/demodulation unit ex302 and the multiplexing/demultiplexing unit ex303 as buffers to avoid system overflows and underflows.

In addition to acquiring audio data and video data from broadcasting and recording media, etc., the TV ex300 has a configuration that accepts AV input from a microphone or camera, and performs encoding processing on the data acquired from them. good too. Although the TV ex300 is described here as being capable of performing the above-described encoding processing, multiplexing, and external output, it cannot perform these processes, and can only perform the above-described reception, decoding processing, and external output. It may be a configuration.

Also, when reading or writing multiplexed data from the recording medium with the reader/recorder ex218, the above decoding processing or encoding processing may be performed by either the TV ex300 or the reader/recorder ex218. The reader/recorder ex 218 may share the work with each other.

As an example, FIG. 36 shows the configuration of the information reproducing/recording section ex400 when reading or writing data from an optical disk. The information reproducing/recording unit ex400 includes elements ex401, ex402, ex403, ex404, ex405, ex406 and ex407 described below. The optical head ex401 irradiates the recording surface of the recording medium ex215, which is an optical disk, with a laser spot to write information, and detects reflected light from the recording surface of the recording medium ex215 to read the information. The modulation recording unit ex402 electrically drives a semiconductor laser built in the optical head ex401, and modulates laser light according to recording data. The reproduction demodulation unit ex403 amplifies a reproduction signal obtained by electrically detecting the reflected light from the recording surface by a photodetector built in the optical head ex401, separates and demodulates the signal components recorded on the recording medium ex215, information. The buffer ex404 temporarily holds information to be recorded on the recording medium ex215 and information reproduced from the recording medium ex215. A 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 to follow the laser spot. The system control unit ex407 controls the entire information reproducing/recording unit ex400. In 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 cooperating the ex403 and the servo control unit ex406. The system control unit ex407 is composed of, for example, a microprocessor, and executes these processes by executing read/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 disk. A guide groove (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 disc is recorded in advance on the information track ex230 by changing 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/reproducing device. can be done. The recording medium ex215 also includes a data recording area ex233, an inner peripheral area ex232, and an outer peripheral area ex234. The area used for recording user data is the data recording area ex233, and the inner circumference area ex232 and the outer circumference area ex234 arranged inside or outside 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 from/to the data recording area ex233 of the recording medium ex215.

In the above, optical discs such as single-layer DVDs and BDs have been described as examples, but the present invention is not limited to these, and optical discs having a multi-layer structure and capable of recording on a surface other than the surface may also be used. Also, optical discs with multi-dimensional recording/reproducing structures, such as recording information using light of different wavelengths and colors in the same location on the disc, and recording different layers of information from various angles. may be

In the digital broadcasting system ex200, a car ex210 having an antenna ex205 can receive data from a satellite ex202 or the like, and can reproduce moving images on a display device such as a car navigation system ex211 of the car ex210. As for the configuration of the car navigation system ex211, for example, among the configurations shown in FIG. 35, a configuration in which a GPS receiving unit is added can be considered.

FIG. 38A is a diagram showing the mobile phone ex114 using the moving image decoding method and moving image encoding method described in the above embodiments. The mobile phone ex114 has an antenna ex350 for transmitting and receiving radio waves to and from the base station ex110, a camera unit ex365 capable of capturing images and still images, images captured by the camera unit ex365, images received by the antenna ex350, etc. has a display unit ex358 such as a liquid crystal display for displaying the decoded data. The mobile phone ex114 further includes a main unit having an operation key 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, captured video, In the memory unit ex367 that stores encoded data or decoded data such as still images, recorded voices, received images, still images, mails, etc., or the interface unit with recording media that similarly stores data It has a certain slot ex364.

Furthermore, a configuration example of the mobile phone ex114 will be described with reference to FIG. 38B. The mobile phone ex114 has a main control unit ex360 that controls all parts of the main unit including a display unit ex358 and an operation key unit ex366. , a camera interface unit ex363, an LCD (Liquid Crystal Display) control unit ex359, a modulation/demodulation unit ex352, a multiplex/separation unit ex353, an audio signal processing unit ex354, a slot unit ex364, and a memory unit ex367 are connected to each other via a bus ex370. ing.

When the user turns off the call and the power key is turned on, the power circuit unit ex361 supplies power from the battery pack to each unit to start the mobile phone ex114 in an operable state.

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

Furthermore, when sending an e-mail in the data communication mode, the text data of the e-mail input by operating the operation key ex366 of the main unit is sent to the main control unit ex360 via the operation input control unit ex362. The main control unit ex360 performs spread spectrum processing on the text data in the modulation/demodulation unit ex352, digital-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, almost the reverse process is performed on the received data, and the data is output to the display unit 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 by the video encoding method shown 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. Also, the audio signal processing unit ex354 encodes an audio signal picked up by the audio input unit ex356 while an image, a still image, etc. is captured by the camera unit ex365, and sends the encoded audio data to the multiplexing/separating unit ex353. do.

The multiplexing/separating 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 obtains A modulation/demodulation unit (modulation/demodulation circuit unit) ex352 performs spectrum spread processing on the multiplexed data.

When receiving video file data linked to a website, etc. in data communication mode, or when receiving e-mail with video and/or audio attached, decode multiplexed data received via antenna ex350 For this purpose, the multiplexing/demultiplexing unit ex353 separates the multiplexed data into a video data bit stream and an audio data bit stream, and processes the encoded video data via a synchronization bus ex370 for video signal processing. The encoded audio data is supplied to the audio signal processing unit ex354 as well as to the audio signal processing unit ex355. The video signal processing unit ex355 decodes the video signal by decoding with a video decoding method corresponding to the video encoding method described in each of the above embodiments (that is, the video signal according to one aspect of the present invention (functions as a decoding device), and video and still images included in a moving image file linked to, for example, a home page are displayed from the display unit ex358 via the LCD control unit ex359. 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 mobile phone ex114, like the TV ex300, can be referred to as transmitting terminals having both encoders and decoders, transmitting terminals having only encoders, and receiving terminals having only decoders. Three implementation forms are conceivable. Furthermore, in the digital broadcasting system ex200, it was explained that multiplexed data in which music data etc. are multiplexed with video data is received and transmitted. or the video data itself instead of the multiplexed data.

In this way, it is possible to use the video encoding method or the video decoding method shown in each of the above embodiments in any of the devices and systems described above. The described effect can be obtained.

Moreover, the present invention is not limited to the above-described embodiments, and various modifications or modifications are possible without departing from the scope of the present invention.

(Embodiment 7)
The video encoding method or apparatus shown in each of the above embodiments and the video encoding method or apparatus conforming to different standards such as MPEG-2, MPEG4-AVC, and VC-1 are appropriately switched as necessary. Thus, it is also possible to generate video data.

Here, when a plurality of pieces of video data conforming to different standards are generated, it is necessary to select a decoding method corresponding to each standard when decoding. However, since it is not possible to identify which standard the video data to be decoded complies with, there arises a problem that an appropriate decoding method cannot be selected.

In order to solve this problem, multiplexed data obtained by multiplexing audio data and the like with video data includes identification information indicating which standard the video data conforms to. A specific configuration of multiplexed data including video data generated by the moving image encoding method or apparatus shown in each of the above embodiments will be described below. The multiplexed data is a digital stream in 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 represents the main video and sub-video of the movie, the audio stream (IG) represents the main audio portion of the movie and sub-audio mixed with the main audio, and the presentation graphics stream represents subtitles of the movie. Here, the main image refers to a normal image displayed on the screen, and the sub-image refers to an image displayed on a small screen within the main image. Also, the interactive graphics stream indicates an interactive screen created by arranging GUI components on the screen. The video stream is encoded by the moving image encoding method or apparatus shown in each of the above embodiments, or by the moving image encoding method or apparatus conforming to conventional standards such as MPEG-2, MPEG4-AVC, and VC-1. ing. The audio stream is encoded in a scheme such as Dolby AC-3, Dolby Digital Plus, MLP, DTS, DTS-HD, or Linear PCM.

Each stream included in multiplexed data is identified by a PID. For example, 0x1011 is used for video streams used for movie images, 0x1100 to 0x111F for audio streams, 0x1200 to 0x121F for presentation graphics, and 0x1400 to 0x141F for interactive graphics streams. 0x1B00 to 0x1B1F are assigned to the video stream used for the sub-picture, and 0x1A00 to 0x1A1F are assigned to the audio stream used for the sub-audio 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 converted 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 the video stream is stored in the PES packet train. The first row in FIG. 41 shows the video frame sequence of the video stream. The second level shows the PES packet sequence. As indicated 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 the video stream, are divided into individual pictures and stored in the payload of the 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 to the multiplexed data. A TS packet is a 188-byte fixed-length packet composed of a 4-byte TS header having information such as a PID that identifies a stream and a 184-byte TS payload that stores data. The PES packet is divided and stored in the TS payload. be. In the case of a BD-ROM, a 4-byte TP_Extra_Header is attached to the TS packet, forming a 192-byte source packet and written into the multiplexed data. Information such as ATS (Arrival_Time_Stamp) is described in TP_Extra_Header. ATS indicates the transfer start time 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 a number incremented from the beginning of the multiplexed data is called an SPN (source packet number).

TS packets included in the multiplexed data include PAT (Program Association Table), PMT (Program Map Table), PCR (Program Clock Reference), etc., in addition to each stream such as video, audio, and subtitles. PAT indicates what the PID of the PMT used in the multiplexed data is, and the PID of 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, attribute information of the stream corresponding to each PID, and various descriptors related to the multiplexed data. The descriptor includes copy control information and the like that instruct permission/non-permission of copying of multiplexed data. PCR corresponds to ATS in which the PCR packet is transferred to the decoder in order to synchronize ATC (Arrival Time Clock), which is the time axis of ATS, and STC (System Time Clock), which is the time axis of PTS/DTS. It has STC time information.

FIG. 43 is a diagram explaining in detail the data structure of the PMT. A PMT header describing 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 described as descriptors. After the descriptor, a plurality of pieces of stream information regarding each stream included in the multiplexed data are arranged. The stream information is composed of a stream descriptor describing a stream type, a stream PID, and stream attribute information (frame rate, aspect ratio, etc.) 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 the multiplexed data information file.

The multiplexed data information file, as shown in FIG. 44, is management information for multiplexed data, corresponds to multiplexed data one-to-one, and consists of multiplexed data information, stream attribute information, and an entry map.

The multiplexed data information consists of system rate, reproduction start time, and reproduction end time, as shown in FIG. The system rate indicates the maximum transfer rate of multiplexed data to the PID filter of the system target decoder, which will be described later. The ATS interval included in the multiplexed data is set to be equal to or less than the system rate. The playback start time is the PTS of the video frame at the beginning of the multiplexed data, and the playback end time is set by adding the playback interval of one frame to the PTS of the video frame at the end of the multiplexed data.

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. Attribute information has different information for each video stream, audio stream, presentation graphics stream, and interactive graphics stream. The video stream attribute information includes what compression codec the video stream was compressed with, what the resolution of each picture data that constitutes the video stream is, what the aspect ratio is, and what the frame rate is. It has information such as how much it is. The audio stream attribute information includes what compression codec the audio stream was compressed with, how many channels the audio stream contains, what languages it supports, what the sampling frequency is, and so on. have information on These pieces of information are used, for example, to initialize the decoder before playback by the player.

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

FIG. 46 shows the steps of the moving picture decoding method according to this embodiment. At step exS100, the stream type included in the PMT or the video stream attribute information included in the multiplexed data information is obtained from the multiplexed data. Next, in step exS101, it is determined whether or not the stream type or the video stream attribute information indicates multiplexed data generated by the video encoding method or apparatus shown in each of the above embodiments. do. Then, when it is determined that the stream type or the video stream attribute information is generated by the video encoding method or apparatus shown in each of the above embodiments, in step exS102, Decoding is performed by the video decoding method shown in the form. Also, if the stream type or video stream attribute information indicates that it conforms to conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc., in step exS103, the conventional Decoding is performed using a video decoding method conforming to the standard.

In this way, by setting a new unique value to the stream type or video stream attribute information, it is possible to determine whether decoding is possible with the video decoding method or device shown in each of the above embodiments. can judge. Therefore, even when multiplexed data conforming to different standards are input, an appropriate decoding method or device can be selected, enabling decoding without causing errors. In addition, the moving image encoding method or apparatus or the moving image decoding method or apparatus described in this embodiment can be used in any of the devices and systems described above.

(Embodiment 8)
The moving image encoding method and apparatus and the moving image decoding method and apparatus described in each of the above embodiments are typically realized by LSI, which is an integrated circuit. As an example, FIG. 47 shows the configuration of LSI ex 500 integrated into one chip. The LSI ex500 includes elements ex501, ex502, ex503, ex504, ex505, ex506, ex507, ex508, and ex509, which will be described below, and these elements are connected via a bus ex510. The power supply circuit unit ex505 starts up in an operable state by supplying power to each unit when the power is on.

For example, when performing encoding processing, the LSI ex 500 controls the microphone ex 117 and camera ex 113 by the AV I/O ex 509 under the control of the control unit ex 501 having the CPU ex 502, memory controller ex 503, stream controller ex 504, drive frequency control unit ex 512, etc. etc. to input the AV signal. The input AV signal is temporarily stored in an external memory ex511 such as SDRAM. Based on the control of the control unit ex501, the accumulated data is appropriately divided into a plurality of times according to the processing amount and processing speed, and sent to the signal processing unit ex507. Encoding of the signal is performed. Here, the encoding process of the video signal is the encoding process described in each of the above embodiments. The signal processing unit ex 507 further performs processing such as multiplexing the encoded audio data and the encoded video data in some cases, and outputs the multiplexed data from the stream I/O ex 506 to the outside. This output multiplexed data is transmitted to the base station ex107 or written to the recording medium ex215. It should be noted that the data should be temporarily stored in the buffer ex508 so as to be synchronized when multiplexing.

In the above description, the memory ex511 is configured outside the LSI ex500, but may be included inside the LSI ex500. The buffer ex508 is also not limited to one, and may have a plurality of buffers. Also, the LSI ex 500 may be formed into one chip, or may be formed into multiple chips.

In the above description, the control unit ex501 includes the CPU ex502, memory controller ex503, stream controller ex504, driving frequency control unit ex512, etc. However, the configuration of the control unit ex501 is not limited to this configuration. For example, the signal processing unit ex507 may be configured to further include a CPU. By providing a CPU inside the signal processing unit ex507, the processing speed can be further improved. 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 CPU ex502 having a signal processing unit ex507 or part thereof.

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

Also, the method of circuit integration is not limited to LSI, and may be realized by 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 the circuit cells inside the LSI may be used. Such a programmable logic device typically loads a program constituting software or firmware or reads it from a memory or the like, thereby performing the moving image encoding method or the moving image encoding method described in each of the above embodiments. An image decoding method can be implemented.

Furthermore, if an integration technology that replaces the LSI appears due to advances in semiconductor technology or another derived technology, the technology may naturally be used to integrate the functional blocks. Adaptation of biotechnology is a possibility.

(Embodiment 9)
When decoding video data generated by the video encoding method or apparatus shown in each of the above embodiments, video data conforming to conventional standards such as MPEG-2, MPEG4-AVC, and VC-1 is decoded. It is conceivable that the amount of processing will increase compared to the case. Therefore, in the LSI ex 500, it is necessary to set the drive frequency higher than the drive frequency of the CPU ex 502 when decoding video data conforming to the conventional standard. However, increasing the drive frequency raises the problem of increased power consumption.

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 switch the drive frequency according to the standard. FIG. 48 shows the configuration ex800 in this embodiment. The driving frequency switching unit ex803 sets a high driving frequency when the video data is generated by the moving image encoding method or apparatus described in each of the above embodiments. Then, it instructs the decoding processing unit ex801, which executes the moving image decoding method shown in each of the above embodiments, to decode the video data. On the other hand, when the video data conforms to the conventional standard, compared to the case where the video data is generated by the video encoding method or apparatus shown in each of the above embodiments, Set the drive frequency low. Then, it instructs the decoding processing unit ex802 conforming to the conventional standard to decode the video data.

More specifically, the driving frequency switching unit ex803 is composed of the CPU ex502 and the driving frequency control unit ex512 shown in FIG. Also, the decoding processing unit ex801 that executes the moving image decoding method shown in each of the above embodiments and the decoding processing unit ex802 conforming to the conventional standard correspond to the signal processing unit ex507 in FIG. The CPUex 502 identifies which standard the video data conforms to. Based on the signal from the CPU ex502, the driving frequency control unit ex512 sets the driving frequency. Also, based on the signal from the CPU ex502, the signal processing unit ex507 decodes the video data. Here, it is conceivable to use the identification information described in Embodiment 7, for example, to identify the video data. The identification information is not limited to that described in the seventh embodiment, and may be any information that can identify which standard the video data complies with. For example, it is possible to identify which standard the video data conforms to based on an external signal that identifies whether the video data is used for a television or a disc. In some cases, identification may be based on such external signals. Also, the selection of the driving frequency in the CPU ex 502 can be considered based on a lookup table, for example, as shown in FIG. A lookup table is stored in the buffer ex508 or the internal memory of the LSI, and the CPUex502 can select the drive frequency by referring to this lookup table.

FIG. 49 shows the steps of implementing the method of this embodiment. First, at step exS200, identification information is obtained from the multiplexed data in the signal processing unit ex507. Next, in step exS201, the CPU ex502 identifies whether or not the video data was generated by the encoding method or apparatus shown in each of the above embodiments based on the identification information. When the video data is generated by the encoding method or apparatus shown in each of the above embodiments, in step exS202, CPU ex502 sends a signal for setting a high driving frequency to driving frequency control section ex512. Then, the driving frequency is set to a high driving frequency in the driving frequency control unit ex512. On the other hand, if it indicates that the video data conforms to conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, then in step exS203, the CPU ex502 drives a signal that sets the driving frequency low. It is sent to the frequency control unit ex512. Then, in the driving frequency control unit ex512, the driving frequency is set to be lower than that in the case where the video data is generated by the encoding method or apparatus shown in each of the above embodiments.

Furthermore, by changing the voltage applied to the LSI ex500 or the device including the LSI ex500 in conjunction with the switching of the drive frequency, it is possible to further enhance the power saving effect. For example, when the drive frequency is set low, the voltage applied to the LSI ex500 or the device including the LSI ex500 may be set lower than when the drive frequency is set high.

In addition, the driving frequency may be set high when the amount of processing in decoding is large, and set low when the amount of processing in decoding is small. The method is not limited. For example, when the amount of processing for decoding video data conforming to the MPEG4-AVC standard is greater than the amount of processing for decoding video data generated by the video encoding method or apparatus shown in each of the above embodiments. For this purpose, it is conceivable to set the drive frequency in the opposite manner as described above.

Furthermore, the method of setting the drive frequency is not limited to the configuration for lowering the drive frequency. For example, if the identification information indicates video data generated by the video encoding method or apparatus shown in each of the above embodiments, the voltage applied to the LSIex500 or the apparatus including the LSIex500 is set high. However, if it indicates that the video data conforms to conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, it may be possible to set the voltage applied to the LSIex500 or the device containing the LSIex500 low. be done. As another example, if the identification information indicates that the video data is generated by the moving image encoding method or apparatus shown in each of the above embodiments, the driving of the CPU ex 502 is stopped. If it indicates that the video data conforms to conventional standards such as MPEG-2, MPEG4-AVC, and VC-1, the drive of the CPU ex 502 is temporarily stopped because there is room for processing. is also conceivable. Even if the identification information indicates that the video data is generated by the moving image encoding method or apparatus shown in each of the above embodiments, if there is room for processing, the drive of the CPU ex 502 may be temporarily suspended. It is also conceivable to stop it. In this case, it is conceivable to set the stop time shorter than in the case of indicating that the video data complies with 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 the LSIex500 or a device including the LSIex500 is driven using a battery, it is possible to extend the life of the battery along with the power saving.

(Embodiment 10)
A plurality of video data conforming to different standards may be input to the devices and systems described above, such as televisions and mobile phones. Thus, in order to be able to decode even when a plurality of video data conforming to different standards are input, the signal processing unit ex507 of the LSI ex500 needs to support a plurality of standards. However, if the signal processing units ex507 corresponding to each standard are individually used, the circuit scale of the LSI ex500 becomes large and the cost increases.

In order to solve this problem, a decoding processing unit for executing the moving image decoding method shown in each of the above embodiments and a decoding unit conforming to conventional standards such as MPEG-2, MPEG4-AVC, VC-1, etc. It is configured to partially share the processing unit. An example of this configuration is shown in ex 900 in FIG. 51A. For example, the moving image decoding method shown in each of the above embodiments and the moving image decoding method conforming to the MPEG4-AVC standard are processed in processes such as entropy coding, inverse quantization, deblocking filtering, and motion compensation. Some contents are common. For common processing content, the decoding processing unit ex 902 compatible with the MPEG4-AVC standard is shared, and for other processing content specific to one aspect of the present invention that does not support the MPEG4-AVC standard, a dedicated decoding processing unit A configuration using ex901 is conceivable. 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 inverse quantization, entropy decoding, and deblocking filter other than that are used. It is conceivable to share the decoding processing unit for any or all of the processing. Regarding the sharing of the decoding processing unit, for the common processing contents, the decoding processing unit for executing the moving image decoding method shown in each of the above embodiments is shared, and the processing contents specific to the MPEG4-AVC standard are shared. may be configured to use a dedicated decoding processing unit.

Further, another example of partially sharing the processing is shown in ex1000 of FIG. 51B. In this example, a dedicated decoding processing unit ex1001 corresponding to processing specific to one aspect of the present invention, a dedicated decoding processing unit ex1002 corresponding to processing specific to another conventional standard, and one aspect of the present invention A common decoding processing unit ex1003 corresponding to the processing contents common to the video decoding method according to the standard and the video decoding method of other conventional standards is used. Here, the dedicated decoding processing units ex1001 and ex1002 are not necessarily specific to one aspect of the present invention or processing content specific to other conventional standards, but are capable of executing other general-purpose processing. good too. Moreover, it is also possible to mount the configuration of this embodiment on the LSIex500.

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

INDUSTRIAL APPLICABILITY The present invention is applicable to an image processing device, an image capturing device, and an image reproducing device. Specifically, the present invention is applicable to digital still cameras, movies, mobile phones with camera functions, smart phones, and the like.

REFERENCE SIGNS LIST 100 image encoding device 101 block division unit 102 subtraction unit 103 frequency transformation unit 104 quantization unit 105 entropy encoding unit 106, 202 inverse quantization unit 107, 203 inverse frequency transformation unit 108, 204 addition unit 109, 205 intra prediction unit 110, 206 loop filter 111, 207 frame memory 112, 208 inter prediction section 113, 209 switching section 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 coding information selection unit 142 motion estimation unit 143 motion compensation unit 144 motion information calculation unit 161 Translation flag 162 Rotation flag 163 Enlargement/reduction flag 164 Shear flag 171 Difference translation component 172 Difference rotation component 173 Difference enlargement/reduction component 174 Difference shear component 181 Coding level information 200 Image decoding device 201 Entropy decoding unit

Claims (2)

a processing circuit;
a storage device accessible from the processing circuit;
The processing circuit uses the storage device to:
Decoding information from a bitstream that is applied to a plurality of blocks included in a picture and that is used to determine the number of parameters used for prediction in prediction based on an affine transformation,
Predicting each of the plurality of blocks included in the picture by performing prediction based on affine transformation using the number of parameters selected by the information, thereby generating a predicted image for each of the plurality of blocks ;
Image decoding device. a processing circuit;
a storage device accessible from the processing circuit;
The processing circuit uses the storage device to:
In prediction based on affine transformation, determining the number of parameters used for prediction,
generating predicted images 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 picture ;
encoding information to be applied to the plurality of blocks included in the picture, the information being used to determine the number of parameters;
Image coding device.

Images