WO2013172074A1 - 画像処理装置及び画像処理方法 - Google Patents
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
- H04N19/59—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving spatial sub-sampling or interpolation, e.g. alteration of picture size or resolution
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
- H04N19/119—Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/102—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the element, parameter or selection affected or controlled by the adaptive coding
- H04N19/12—Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
- H04N19/122—Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/10—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding
- H04N19/169—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding
- H04N19/187—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using adaptive coding characterised by the coding unit, i.e. the structural portion or semantic portion of the video signal being the object or the subject of the adaptive coding the unit being a scalable video layer
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- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/30—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using hierarchical techniques, e.g. scalability
- H04N19/33—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using hierarchical techniques, e.g. scalability in the spatial domain
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/50—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding
- H04N19/503—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using predictive coding involving temporal prediction
- H04N19/51—Motion estimation or motion compensation
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- H04N19/00—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals
- H04N19/60—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding
- H04N19/61—Methods or arrangements for coding, decoding, compressing or decompressing digital video signals using transform coding in combination with predictive coding
Definitions
- the present disclosure relates to an image processing apparatus and an image processing method.
- Scalable encoding (also referred to as SVC (Scalable Video Coding) generally refers to a technique for hierarchically encoding a layer that transmits a coarse image signal and a layer that transmits a fine image signal.
- Typical attributes hierarchized in scalable coding are mainly the following three types. Spatial scalability: Spatial resolution or image size is layered. -Time scalability: Frame rate is layered. -SNR (Signal to Noise Ratio) scalability: SN ratio is hierarchized. In addition, bit depth scalability and chroma format scalability are also discussed, although not yet adopted by the standard.
- encoding efficiency can be improved by encoding parameters that can be shared between layers only within one layer.
- the quad-tree structure is formed from the beginning in the enhancement layer while completely ignoring the macroblock structure in the base layer, the mapping of blocks between layers is lost. In this case, it becomes difficult to reuse various parameters set for each block between layers, the advantages of scalable coding are lost, and coding efficiency is reduced.
- a first setting unit that sets a macroblock in a base layer that is decoded by a first encoding method based on a macroblock having a fixed size, and encoding that is recursively divided into blocks
- An image processing apparatus comprising: a second setting unit that sets a coding unit according to a block size set by the first setting unit in an enhancement layer decoded by a second coding method based on a unit Is provided.
- the image processing apparatus can typically be realized as an image decoding apparatus that decodes an image.
- a macroblock is set in a base layer that is decoded by a first encoding scheme based on a macroblock having a fixed size, and an encoding unit that is recursively divided into blocks.
- An image processing method includes: setting an encoding unit in an enhancement layer decoded by a second encoding method based on the block size according to a block size set in the base layer.
- the first setting unit that sets the macroblock in the base layer encoded by the first encoding method based on the macroblock having a fixed size, and the block division recursively.
- a second setting unit that sets a coding unit according to a block size set by the first setting unit in an enhancement layer encoded by the second coding method based on the coding unit.
- the image processing apparatus can typically be realized as an image encoding apparatus that encodes an image.
- a macroblock is set in a base layer that is encoded by a first encoding scheme based on a macroblock having a fixed size, and recursive block division encoding is performed.
- an image processing method including: setting an encoding unit in an enhancement layer encoded by a second encoding method based on a unit according to a block size set in the base layer.
- FIG. 20 is a block diagram illustrating an example of a detailed configuration of a block setting unit illustrated in FIG. 19.
- FIG. 20 is a block diagram illustrating an example of a detailed configuration of an inverse orthogonal transform unit illustrated in FIG. 19.
- FIG. 20 is a block diagram which shows an example of a detailed structure of the intra estimation part shown in FIG.
- FIG. 20 is a block diagram illustrating an example of a detailed configuration of an inter prediction unit illustrated in FIG. 19.
- the base layer is a layer that expresses the coarsest image that is encoded first.
- the base layer coded stream may be decoded independently without decoding the other layer coded streams.
- a layer other than the base layer is a layer called an enhancement layer (enhancement layer) that represents a finer image.
- the enhancement layer encoded stream is encoded using information included in the base layer encoded stream. Accordingly, in order to reproduce the enhancement layer image, both the base layer and enhancement layer encoded streams are decoded.
- the number of layers handled in scalable coding may be any number of two or more.
- the lowest layer is the base layer
- the remaining layers are enhancement layers.
- the higher enhancement layer encoded stream may be encoded and decoded using information contained in the lower enhancement layer or base layer encoded stream.
- a layer on which the dependency is made is referred to as a lower layer
- a layer on which the dependency is concerned is referred to as an upper layer.
- FIG. 1 shows three layers L1, L2 and L3 to be scalable encoded.
- Layer L1 is a base layer
- layers L2 and L3 are enhancement layers.
- spatial scalability is taken as an example among various types of scalability.
- the ratio of the spatial resolution of layer L3 to layer L1 is 4: 1.
- the base layer L1 is encoded by a macroblock-based image encoding method such as MPEG2 or AVC.
- the block B1 of the base layer L1 is one macro block.
- the size of the macroblock is fixedly defined, and the macroblock B1 has a size of 16 ⁇ 16 pixels.
- the enhancement layer L2 is also encoded by the macroblock-based image encoding method, the scalability ratio of the layer L2 to the layer L1 is 2.0, so the image in the enhancement layer L2 corresponding to the block B1
- the region can be divided into four macroblocks B21, B22, B23 and B24.
- FIG. 2 is an explanatory diagram for explaining a quad-tree structure of a coding unit in HEVC.
- an image IM01 in which a person's face is shown is shown.
- the image IM01 is first divided into a plurality of LCUs (maximum coding units: Large Coding Units) having a size specified in the sequence parameter set (SPS).
- SPS sequence parameter set
- each LCU is recursively divided into one or more CUs (Coding Units) within a range that is not less than the SCU (Smallest Coding Unit) specified in the SPS. .
- the right side of FIG. 2 shows an enlarged view of LCU0 crossing a texture boundary being recursively divided into a plurality of CUs. In the region near the texture boundary, a smaller CU is set by repeating the division, and in other regions, a larger CU is set by reducing the number of divisions. For example, if the size of LCU0 is 64 ⁇ 64 pixels, the size of CU01 is 32 ⁇ 32 pixels, the size of CU02 is 16 ⁇ 16 pixels, and the size of CU03 is 8 ⁇ 8 pixels.
- each CU is divided into a plurality of TUs (transform units) that are orthogonal transform processing units. Further, each CU is divided into a plurality of PUs (prediction units) which are processing units for intra prediction or inter prediction. According to such recursive block division, it is possible to increase the encoding efficiency of a high-definition image by flexibly changing the size of the processing unit of the encoding process according to the content of the image.
- the base layer L1 is encoded with AVC and the enhancement layer L2 is encoded with HEVC, according to the simplest technique, it is composed of blocks B21, B22, B23 and B24.
- one CU of 32 ⁇ 32 pixels corresponding to the block B1 can be set in the enhancement layer L2.
- the quad-tree structure is formed from the beginning in the enhancement layer L2 while completely ignoring the macroblock structure in the base layer L1, the mapping of blocks between layers is lost. In this case, it becomes difficult to reuse various parameters set for each block between layers, and the coding efficiency is not optimized.
- mapping of blocks between layers in the multi-codec scalable coding is defined so that these problems are solved or at least partially improved.
- An example of the configuration of an apparatus that encodes or decodes an image according to the mapping will be described.
- the base layer is encoded with AVC (Advanced Video Coding) and the enhancement layer is encoded with HEVC (High Efficiency Video Coding).
- AVC Advanced Video Coding
- HEVC High Efficiency Video Coding
- the technology according to the present disclosure is not limited to such an example, and other image encoding scheme combinations (for example, the base layer is encoded with MPEG2 and the enhancement layer is encoded with HEVC). Applicable. Further, the technology according to the present disclosure can be applied not only to the spatial scalability illustrated in FIG. 1 but also to SNR scalability, bit depth scalability, and chroma format scalability.
- mapping for coding units As a basic concept of mapping related to CU, in the technology according to the present disclosure, a CU is set in an enhancement layer encoded by HEVC in accordance with a block size of a macroblock set in the base layer. That is, in the enhancement layer, the Quad-Tree structure is not formed from scratch, but the Quad-Tree structure is formed using the macroblock size in the base layer.
- the LCU size in the enhancement layer is set equal to or larger than the product of the macroblock size and the scalability ratio in the base layer.
- the actually set LCU size may be determined deterministically as a size closest to the product among available sizes, or may be selected from a plurality of sizes narrowed down based on the product. Good. Each LCU set in this way may be flexibly divided into smaller CUs regardless of the macroblock size in the base layer.
- FIG. 3A is an explanatory diagram for describing a first method for setting the HEVC LCU size.
- the LCU size is determined by decisive action.
- the left side of FIG. 3A shows a macroblock having a block size of 16 ⁇ 16 pixels in AVC.
- the right side of FIG. 3A shows four LCUs each having four types of block sizes (64 ⁇ 64 pixels, 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, and 8 ⁇ 8 pixels) that can be used in HEVC.
- the scalability ratio SR 2.0
- the LCU size in the enhancement layer may be set to 32 ⁇ 32 pixels.
- the LCU size when 3.0 ⁇ SR, the LCU size is 64 ⁇ 64 pixels, and when 1.5 ⁇ SR ⁇ 3.0, the LCU size is 32 ⁇ 32 pixels, and 1.0 ⁇ When SR ⁇ 1.5, the LCU size may be set to 16 ⁇ 16 pixels. According to such a first method, the LCU size can be determined in the enhancement layer without additionally encoding a parameter indicating the LCU size.
- FIG. 3B is an explanatory diagram for describing a second method for setting the HEVC LCU size.
- an LCU size of 64 ⁇ 64 pixels is selected, and if not, an LCU size of 32 ⁇ 32 pixels is selected. May be.
- a parameter indicating the LCU size is additionally generated in the enhancement layer, and the generated parameter is encoded.
- the candidates for the LCU size to be selected are narrowed down, the number of bits of the parameter to be additionally encoded can be smaller than in the case where all types of LCU sizes can be selected. In the example of FIG.
- the number of bits of the additionally encoded parameter is 1, for example, the parameter value “0” may indicate 64 ⁇ 64 pixels, and the parameter value “1” may indicate 32 ⁇ 32 pixels (that is, The reverse may also be true). According to such a second method, it is possible to reduce the code amount of the parameter indicating the LCU size while leaving the flexibility of selection of the LCU size in the enhancement layer.
- the method for narrowing down the candidates for the LCU size is not limited to the method illustrated in FIG. 3B.
- the scalability ratio is not equal to a power of 2
- an LCU size that matches the product of the macroblock size and the scalability ratio is not available in HEVC.
- LCU size candidates may be narrowed down to the smallest of the available LCU sizes larger than the product and the largest of the available LCU sizes smaller than the product.
- the scalability ratio SR 1.5
- a 1-bit parameter indicating which LCU size has been selected is generated, and the generated parameter is encoded.
- the decoder decodes such parameters and selects the LCU size with reference to the decoded parameters. Similar ideas may be applied to narrowing down the SCU size, TU size, and PU size described below.
- the SCU size in the enhancement layer can be set to a value equal to or smaller than the LCU size so that a desired block division is possible.
- the SCU size may be determined without depending on the block size of the base layer. Instead, the SCU size may be determined according to the product of the sub macroblock size and the scalability ratio when the sub macroblock size is defined in the base layer.
- FIG. 4A is an explanatory diagram for describing a first technique for setting the SVC size of HEVC.
- the SCU size is determined by decisive action.
- the left side of FIG. 4A shows a sub macroblock having a block size of 8 ⁇ 8 pixels in AVC.
- the right side of FIG. 4A shows four SCUs each having four types of block sizes (64 ⁇ 64 pixels, 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, and 8 ⁇ 8 pixels).
- the SCU size in the enhancement layer may be set to 16 ⁇ 16 pixels.
- the SCU size when 3.0 ⁇ SR, the SCU size is 32 ⁇ 32 pixels, and when 1.5 ⁇ SR ⁇ 3.0, the SCU size is 32 ⁇ 32 pixels, and 1.0 ⁇ When SR ⁇ 1.5, the SCU size may be set to 16 ⁇ 16 pixels. According to such a first method, the SCU size can be determined in the enhancement layer without additionally encoding a parameter indicating the SCU size.
- FIG. 4B is an explanatory diagram for describing a second method for setting the SVC size of HEVC.
- the SCU size is selected from a plurality of sizes equal to or smaller than the LCU size.
- the LCU size is set to 32 ⁇ 32 pixels.
- SCU size candidates may include 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, and 8 ⁇ 8 pixels.
- a smaller SCU size may be selected if it is desirable to allow finer block partitioning.
- a parameter indicating the SCU size (SCU size information) is additionally generated in the enhancement layer, and the generated parameter is encoded.
- the parameter value “0” can indicate 32 ⁇ 32 pixels
- the parameter value “1” can indicate 16 ⁇ 16 pixels
- the parameter value “2” can indicate 8 ⁇ 8 pixels.
- mapping for conversion unit The basic idea of mapping for TUs is similar to mapping for CUs.
- the size of the TU set in the enhancement layer is determined according to the size of the transform block set in the base layer, that is, the DCT (Discrete Cosine Transform) size.
- the DCT size of a transform block that is a unit of orthogonal transform is selected from 8 ⁇ 8 pixels and 4 ⁇ 4 pixels.
- the size (that is, TU size) of a transform block that is a unit of orthogonal transform is selected from 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, and 4 ⁇ 4 pixels.
- the TU size actually set in the enhancement layer may be determined as a size closest to the product of the DCT size set in the base layer and the scalability ratio among the available sizes. Instead, the TU size that is actually set may be selected from a plurality of sizes that are narrowed down based on the product.
- FIG. 5A is an explanatory diagram for describing a first method for setting a HEVC TU.
- the TU size is determined by decisive action.
- a dotted line frame indicates that a DCT size of 8 ⁇ 8 pixels is set in AVC.
- the right side of FIG. 5A shows four TUs each having four types of TU sizes (32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, and 4 ⁇ 4 pixels) that can be used in HEVC.
- the scalability ratio SR 2.0
- the TU size in the enhancement layer may be set to 16 ⁇ 16 pixels.
- the TU size when 3.0 ⁇ SR, the TU size is 32 ⁇ 32 pixels, and when 1.5 ⁇ SR ⁇ 3.0, the TU size is 16 ⁇ 16 pixels, and 1.0 ⁇ When SR ⁇ 1.5, the TU size may be set to 8 ⁇ 8 pixels. According to such a first method, the TU size can be determined in the enhancement layer without additionally encoding a parameter indicating the TU size.
- FIG. 5B is an explanatory diagram for describing a second method for setting a HEVC TU.
- the TU size is selected from one or more size candidates that are narrowed down based on the product of the DCT size and the scalability ratio.
- the coding efficiency is improved.
- the TU size candidates in the enhancement layer are narrowed down to two types of 32 ⁇ 32 pixels and 16 ⁇ 16 pixels. Then, a parameter (TU size information) indicating the actually set TU size is additionally generated, and the generated parameter is encoded.
- a parameter indicating the actually set TU size is additionally generated, and the generated parameter is encoded.
- the TU size candidates in the enhancement layer are narrowed down to two types of 8 ⁇ 8 pixels and 4 ⁇ 4 pixels. Then, a parameter (TU size information) indicating the actually set TU size is additionally generated, and the generated parameter is encoded.
- TU size candidates are narrowed down, the number of bits of the parameter to be additionally encoded can be smaller than in the case where all types of TU sizes can be selected. According to such a second method, in the enhancement layer, it is possible to reduce the code amount of the parameter indicating the TU size while leaving the flexibility of selecting the TU size.
- mapping for prediction units The basic idea of mapping for PU is similar to mapping for TU.
- the size of the PU set in the enhancement layer is determined according to the size of the prediction block set in the base layer.
- the size of a prediction block (that is, the prediction block size) serving as a prediction processing unit is selected from 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, and 4 ⁇ 4 pixels for intra prediction.
- the size (ie, PU size) of a prediction block serving as a prediction processing unit is 64 ⁇ 64 pixels, 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, and 4 ⁇ 4 pixels for intra prediction. Selected.
- non-square prediction block sizes are also available.
- the PU size actually set in the enhancement layer may be determined as a size closest to the product of the predicted block size set in the base layer and the scalability ratio among the available sizes. Instead, the PU size that is actually set may be selected from a plurality of sizes that are narrowed down based on the product.
- FIG. 6A is an explanatory diagram for describing a first method for setting a PU of HEVC.
- intra prediction is an object of description.
- the PU size is determined by decisive action.
- a dotted line frame indicates that a predicted block size of 4 ⁇ 4 pixels is set in AVC.
- the right side of FIG. 6A shows four PUs each having four types of PU sizes (32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, and 4 ⁇ 4 pixels).
- the scalability ratio SR 2.0
- the PU size in the enhancement layer may be set to 8 ⁇ 8 pixels.
- the PU size when 6.0 ⁇ SR, the PU size is 32 ⁇ 32 pixels, and when 3.0 ⁇ SR ⁇ 6.0, the PU size is 16 ⁇ 16 pixels, and 1.5 ⁇ SR.
- the PU size When SR ⁇ 3.0, the PU size may be set to 8 ⁇ 8 pixels, and when 1.0 ⁇ SR ⁇ 1.5, the PU size may be set to 4 ⁇ 4 pixels.
- the PU size can be determined in the enhancement layer without additionally encoding a parameter indicating the PU size.
- FIG. 6B is an explanatory diagram for explaining a second method for setting the PU of HEVC.
- intra prediction is an object of description.
- the PU size is selected from one or more size candidates that are narrowed down based on the product of the predicted block size and the scalability ratio.
- a prediction block size larger than 4 ⁇ 4 pixels has not been selected in the base layer, encoding is performed even if a prediction block size larger than 8 ⁇ 8 pixels is excluded from the candidates in the enhancement layer. It can be said that there is no negative effect on efficiency. Therefore, in this case, PU size candidates in the enhancement layer are narrowed down to two types of 8 ⁇ 8 pixels and 4 ⁇ 4 pixels. Then, a parameter (PU size information) indicating the actually set PU size is additionally generated, and the generated parameter is encoded.
- the PU size candidates in the enhancement layer are only 16 ⁇ 16 pixels. Become. In this case, a 16 ⁇ 16 pixel PU size may inevitably be set in the enhancement layer, and a parameter indicating the PU size is not generated. In any case, since the PU size candidates are narrowed down, the number of bits of the parameter to be additionally encoded can be smaller than in the case where all types of PU sizes can be selected. According to such a second method, in the enhancement layer, it is possible to reduce the code amount of the parameter indicating the PU size while leaving the flexibility of selecting the PU size.
- FIG. 7A shows prediction block size candidates that can be used in AVC inter prediction.
- inter prediction when a prediction block having a size of 8 ⁇ 8 pixels or less is used in AVC, that is, when division into sub-macro blocks is used, a sub-macro block indicating the shape and size of the sub-macro block is used.
- a parameter called type is encoded. Therefore, in the enhancement layer, PU size candidates may be narrowed down depending on whether division into sub macroblocks is used, that is, whether a sub macroblock type is encoded.
- FIG. 7B is an explanatory diagram for describing a third method for setting the PU size for HEVC inter prediction.
- PU size information indicating the actually set PU size
- PU size candidates in the enhancement layer can be narrowed down to a size of 8 ⁇ 8 pixels or less. . Then, a parameter (PU size information) indicating the actually set PU size is additionally generated, and the generated parameter is encoded.
- the PU size candidates are narrowed down, the number of bits of the parameter to be additionally encoded can be smaller than in the case where all types of PU sizes can be selected.
- the code amount of the parameter indicating the PU size can be reduced while leaving the flexibility of selecting the PU size.
- FIG. 8 is a block diagram illustrating a schematic configuration of an image encoding device 10 according to an embodiment that supports scalable encoding.
- the image encoding device 10 includes a first encoding unit 1a, a second encoding unit 1b, a common memory 2, and a multiplexing unit 3.
- the first encoding unit 1a encodes the base layer image and generates an encoded stream of the base layer.
- the second encoding unit 1b encodes the enhancement layer image and generates an enhancement layer encoded stream.
- the common memory 2 stores information commonly used between layers.
- the multiplexing unit 3 multiplexes the encoded stream of the base layer generated by the first encoding unit 1a and the encoded stream of one or more enhancement layers generated by the second encoding unit 1b. A multiplexed stream of layers is generated.
- FIG. 9 is a block diagram illustrating a schematic configuration of an image decoding device 60 according to an embodiment that supports scalable coding.
- the image decoding device 60 includes a demultiplexing unit 5, a first decoding unit 6 a, a second decoding unit 6 b, and a common memory 7.
- the demultiplexing unit 5 demultiplexes the multi-layer multiplexed stream into a base layer encoded stream and one or more enhancement layer encoded streams.
- the first decoding unit 6a decodes the base layer image from the base layer encoded stream.
- the second decoding unit 6b decodes the enhancement layer image from the enhancement layer encoded stream.
- the common memory 7 stores information commonly used between layers.
- the configuration of the first encoding unit 1a for encoding the base layer and the configuration of the second encoding unit 1b for encoding the enhancement layer are: Although there are differences in encoding schemes, they are similar to each other. Some parameters generated or acquired by the first encoding unit 1a are buffered using the common memory 2 and reused by the second encoding unit 1b. In the next section, the configuration of the first encoding unit 1a and the second encoding unit 1b will be described in detail.
- the configuration of the first decoding unit 6 a for decoding the base layer and the configuration of the second decoding unit 6 b for decoding the enhancement layer are image coding. Although there are differences in methods, they are similar to each other. Some parameters generated or acquired by the first decoding unit 6a are buffered using the common memory 7 and reused by the second decoding unit 6b. Further, in the next section, the configuration of the first decoding unit 6a and the second decoding unit 6b will be described in detail.
- FIG. 10 is a block diagram illustrating an example of the configuration of the first encoding unit 1a and the second encoding unit 1b illustrated in FIG.
- the first encoding unit 1a includes a rearrangement buffer 11, a block setting unit 12a, a subtraction unit 13, an orthogonal transformation unit 14a, a quantization unit 15, a lossless encoding unit 16a, an accumulation buffer 17, and a rate control.
- the second encoding unit 1b includes a block setting unit 12b, an orthogonal transform instead of the block setting unit 12a, the orthogonal transform unit 14a, the lossless encoding unit 16a, the inverse orthogonal transform unit 22a, the intra prediction unit 30a, and the inter prediction unit 40a.
- the rearrangement buffer 11 rearranges images included in a series of image data.
- the rearrangement buffer 11 rearranges the images according to a GOP (Group of Pictures) structure related to the encoding process, and then outputs the rearranged image data to the block setting unit 12a or 12b.
- GOP Group of Pictures
- the block setting unit 12a sets one or more macroblocks in the base layer image data input from the rearrangement buffer 11.
- the macroblock size is fixedly defined in AVC, and the macroblock size is stored in advance in the common memory 2. Then, the block setting unit 12a outputs the image data to the subtraction unit 13, the intra prediction unit 30a, and the inter prediction unit 40a for each set macroblock.
- the block setting unit 12b sets the LCU size and the SCU size for the enhancement layer image data input from the rearrangement buffer 11.
- the setting of the LCU size and the SCU size may be changed for each sequence.
- the block setting unit 12b can determine the LCU size using the macroblock size and the scalability ratio stored in the common memory 2.
- the SCU size may be further determined by referring to a sub macroblock size that can be stored by the common memory 2. Then, the block setting unit 12b outputs the image data to the subtraction unit 13, the intra prediction unit 30b, and the inter prediction unit 40b for each set LCU.
- the subtraction unit 13 is supplied with image data input from the block setting unit 12a or 12b and predicted image data input from the intra prediction unit 30a or 30b or the inter prediction unit 40a or 40b described later.
- the subtraction unit 13 calculates prediction error data that is a difference between the image data input from the rearrangement buffer 11 and the prediction image data, and outputs the calculated prediction error data to the orthogonal transformation unit 14a or 14b.
- the orthogonal transform unit 14a sets a transform block in the macro block for the base layer prediction error data input from the subtraction unit 13, and performs orthogonal transform for each set transform block.
- the orthogonal transform executed by the orthogonal transform unit 14a may be, for example, a discrete cosine transform (DCT).
- the size of the transform block set by the orthogonal transform unit 14a is 8 ⁇ 8 pixels or 4 ⁇ 4 pixels.
- the orthogonal transform unit 14 a outputs transform coefficient data acquired by orthogonal transform processing for each transform block to the quantization unit 15. Further, the orthogonal transform unit 14 a causes the common memory 2 to buffer DCT size information indicating the size of each set transform block.
- the orthogonal transform unit 14b sets the TU in the LCU for the enhancement layer prediction error data input from the subtraction unit 13, and performs orthogonal transform for each set TU.
- the orthogonal transform performed by the orthogonal transform unit 14b may also be a discrete cosine transform (DCT).
- the size of the TU set by the orthogonal transform unit 14b is 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, or 4 ⁇ 4 pixels.
- the orthogonal transform unit 14 b can determine the TU size to be set in the enhancement layer using the DCT size information and the scalability ratio of the base layer stored in the common memory 2.
- the orthogonal transform unit 14 b outputs transform coefficient data acquired by the orthogonal transform process for each TU to the quantization unit 15.
- the quantization unit 15 is supplied with transform coefficient data input from the orthogonal transform unit 14a or 14b and a rate control signal from the rate control unit 18 described later.
- the quantization unit 15 quantizes the transform coefficient data and outputs the quantized transform coefficient data (hereinafter referred to as quantized data) to the lossless encoding unit 16a or 16b and the inverse quantization unit 21.
- the quantization unit 15 changes the bit rate of the quantized data by switching the quantization parameter (quantization scale) based on the rate control signal from the rate control unit 18.
- the lossless encoding unit 16a generates a base layer encoded stream by performing lossless encoding processing on the base layer quantized data input from the quantization unit 15. Further, the lossless encoding unit 16a encodes information on various block sizes set in the base layer, and multiplexes the encoding parameters in the header area of the encoded stream.
- the information encoded here may include, for example, DCT size information, information related to intra prediction, and information related to inter prediction. Then, the lossless encoding unit 16 a outputs the generated encoded stream to the accumulation buffer 17.
- the lossless encoding unit 16b generates an enhancement layer encoded stream by performing lossless encoding processing on the enhancement layer quantized data input from the quantization unit 15. Further, the lossless encoding unit 16b encodes information regarding various block sizes set in the enhancement layer, and multiplexes the encoding parameter in the header region of the encoded stream.
- the information encoded here may include, for example, scalability ratio, block size information, a split flag (split_flag) indicating block division in each LCU, information on intra prediction, and information on inter prediction. Then, the lossless encoding unit 16 b outputs the generated encoded stream to the accumulation buffer 17.
- the accumulation buffer 17 temporarily accumulates the base layer encoded stream input from the lossless encoding unit 16a and the enhancement layer encoded stream input from the lossless encoding unit 16b using a storage medium such as a semiconductor memory. To do. Then, the accumulation buffer 17 outputs the accumulated encoded stream to a transmission unit (not shown) (for example, a communication interface or a connection interface with a peripheral device) at a rate corresponding to the bandwidth of the transmission path.
- a transmission unit for example, a communication interface or a connection interface with a peripheral device
- the rate control unit 18 monitors the free capacity of the accumulation buffer 17. Then, the rate control unit 18 generates a rate control signal according to the free capacity of the accumulation buffer 17 and outputs the generated rate control signal to the quantization unit 15. For example, the rate control unit 18 generates a rate control signal for reducing the bit rate of the quantized data when the free capacity of the storage buffer 17 is small. For example, when the free capacity of the accumulation buffer 17 is sufficiently large, the rate control unit 18 generates a rate control signal for increasing the bit rate of the quantized data.
- the inverse quantization unit 21 performs an inverse quantization process on the quantized data input from the quantization unit 15. Then, the inverse quantization unit 21 outputs transform coefficient data acquired by the inverse quantization process to the inverse orthogonal transform unit 22a or 22b.
- the inverse orthogonal transform unit 22a restores prediction error data by performing an inverse orthogonal transform process on the transform coefficient data of the base layer input from the inverse quantization unit 21 for each transform block set by the orthogonal transform unit 14a. To do. Then, the inverse orthogonal transform unit 22 a outputs the restored prediction error data to the addition unit 23.
- the inverse orthogonal transform unit 22b restores the prediction error data by performing an inverse orthogonal transform process on the enhancement layer transform coefficient data input from the inverse quantization unit 21 for each TU set by the orthogonal transform unit 14b. . Then, the inverse orthogonal transform unit 22 b outputs the restored prediction error data to the addition unit 23.
- the adding unit 23 adds the restored prediction error data input from the inverse orthogonal transform unit 22a or 22b and the predicted image data input from the intra prediction unit 30a or 30b or the inter prediction unit 40a or 40b, Decoded image data (so-called reconstructed image) is generated. Then, the addition unit 23 outputs the generated decoded image data to the deblock filter 24 and the frame memory 25.
- the deblocking filter 24 performs a filtering process for reducing block distortion that occurs during image coding.
- the deblocking filter 24 removes block distortion by filtering the decoded image data input from the adding unit 23, and outputs the decoded image data after filtering to the frame memory 25.
- the frame memory 25 stores the decoded image data input from the adder 23 and the decoded image data after filtering input from the deblock filter 24 using a storage medium.
- the selector 26 reads out the decoded image data before filtering used for intra prediction from the frame memory 25, and supplies the read decoded image data to the intra prediction unit 30a or 30b as reference image data. Further, the selector 26 reads out the decoded image data after filtering used for inter prediction from the frame memory 25, and supplies the read out decoded image data to the inter prediction unit 40a or 40b as reference image data.
- the selector 27 In the intra prediction mode, the selector 27 outputs the prediction image data as a result of the intra prediction output from the intra prediction unit 30a or 30b to the subtraction unit 13 and information related to the intra prediction to the lossless encoding unit 16a or 16b. Output. Further, in the inter prediction mode, the selector 27 outputs the prediction image data as a result of the inter prediction output from the inter prediction unit 40a or 40b to the subtraction unit 13 and also transmits information regarding the inter prediction to the lossless encoding unit 16a or To 16b. The selector 27 switches between the intra prediction mode and the inter prediction mode according to the size of the cost function value.
- the intra prediction unit 30a performs an intra prediction process for each AVC prediction block based on the original image data and decoded image data of the base layer. For example, the intra prediction unit 30a sets a prediction block in a macroblock, and executes intra prediction for each set prediction block.
- the size of the prediction block set by the intra prediction unit 30a is 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, or 4 ⁇ 4 pixels.
- the intra prediction unit 30a evaluates the prediction result in each prediction mode using a predetermined cost function.
- the intra prediction unit 30a selects the prediction mode with the smallest cost function value, that is, the prediction mode with the highest compression rate, as the optimum prediction mode.
- the intra prediction unit 30a generates base layer predicted image data in accordance with the optimal prediction mode.
- the intra prediction unit 30 a outputs information related to intra prediction including prediction mode information representing the selected optimal prediction mode, cost function values, and predicted image data to the selector 27. Further, the intra prediction unit 30 a buffers the prediction block size information by the common memory 2.
- the intra prediction unit 30b performs an intra prediction process for each PU of HEVC based on the original image data and decoded image data of the enhancement layer. For example, the intra prediction unit 30b sets PUs in the LCU and executes intra prediction for each set PU.
- the size of the PU set by the intra prediction unit 30b is 64 ⁇ 64 pixels, 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, or 4 ⁇ 4 pixels.
- the intra prediction unit 30b may determine the PU size to be set in the enhancement layer using the base layer prediction block size information and the scalability ratio stored in the common memory 2. Next, the intra prediction unit 30b evaluates the prediction result in each prediction mode using a predetermined cost function.
- the intra prediction unit 30b selects a prediction mode with the smallest cost function value, that is, a prediction mode with the highest compression rate, as the optimum prediction mode. Moreover, the intra estimation part 30b produces
- the inter prediction unit 40a performs inter prediction processing (motion search processing) for each AVC prediction block based on the original image data and decoded image data of the base layer. For example, the inter prediction unit 40a sets a prediction block in a macroblock, and performs inter prediction for each set prediction block. The size of the prediction block set by the inter prediction unit 40a is one of the seven sizes shown in FIG. 7A. Next, the inter prediction unit 40a evaluates the prediction result in each prediction mode using a predetermined cost function. Next, the inter prediction unit 40a selects a prediction mode with the smallest cost function value, that is, a prediction mode with the highest compression rate, as the optimum prediction mode. In addition, the inter prediction unit 40a generates base layer predicted image data according to the optimal prediction mode.
- inter prediction processing motion search processing
- the inter prediction unit 40 a outputs information related to inter prediction including motion information corresponding to the selected optimal prediction mode, cost function values, and predicted image data to the selector 27.
- the inter prediction unit 40 a causes the common memory 2 to buffer the predicted block size information.
- the predicted block size information may include a sub macroblock type.
- the inter prediction unit 40b performs inter prediction processing (motion search processing) for each PU of HEVC based on the original image data and decoded image data of the enhancement layer. For example, the inter prediction unit 40b sets PUs in the LCU and performs inter prediction for each set PU. The inter prediction unit 40b may determine the PU size to be set in the enhancement layer using the base layer prediction block size information and the scalability ratio stored in the common memory 2. Next, the inter prediction unit 40b evaluates the prediction result in each prediction mode using a predetermined cost function. Next, the inter prediction unit 40b selects a prediction mode in which the cost function value is minimum, that is, a prediction mode in which the compression rate is the highest, as the optimal prediction mode.
- inter prediction processing motion search processing
- the inter prediction unit 40b generates enhancement layer predicted image data according to the optimal prediction mode. Then, the inter prediction unit 40 b outputs information on inter prediction including motion information corresponding to the selected optimal prediction mode, a cost function value, and predicted image data to the selector 27.
- the first encoding unit 1a executes the series of encoding processes described here for a series of image data of the base layer.
- the second encoding unit 1b performs the series of encoding processes described here on a series of image data of the enhancement layer.
- the enhancement layer encoding process may be repeated by the number of enhancement layers.
- FIG. 11 is a block diagram illustrating an example of a detailed configuration of the block setting units 12a and 12b illustrated in FIG.
- the block setting unit 12a includes a setting control unit 111a and a macroblock setting unit 112a.
- the block setting unit 12b includes a setting control unit 111b and a CU setting unit 112b.
- the setting control unit 111a of the block setting unit 12a acquires a fixed macroblock size stored in advance in the common memory 2, and sets a macroblock having the acquired size as a macroblock.
- the setting unit 112a is instructed.
- the macroblock setting unit 112a sets one or more macroblocks in the base layer image data in accordance with an instruction from the setting control unit 111a. Then, the macroblock setting unit 112a outputs the image data to the subtraction unit 13, the intra prediction unit 30a, and the inter prediction unit 40a for each set macroblock.
- the setting control unit 111b of the block setting unit 12b acquires the macroblock size stored in the common memory 2 and the scalability ratio between the base layer and the enhancement layer.
- the scalability ratio may be stored in advance by the common memory 2 or may be calculated from the resolution data of the two layers. Then, the setting control unit 111b instructs the CU setting unit 112b to set the LCU size and the SCU size determined using the macroblock size and the scalability ratio.
- the CU setting unit 112b sets the LCU size and the SCU size in the enhancement layer in response to an instruction from the setting control unit 111b.
- the CU setting unit 112b may determine the LCU size in a definitive manner by multiplying the macroblock size by the scalability ratio according to the first method described with reference to FIG. 3A. Instead, the CU setting unit 112b determines the size selected from a plurality of size candidates to be narrowed down based on the product of the macroblock size and the scalability ratio according to the second method described with reference to FIG. 3B. May be determined as In the latter case, the CU setting unit 112b generates LCU size information indicating the selected LCU size.
- the CU setting unit 112b determines the SCU size by deterministically by multiplying the sub macroblock size stored in advance by the common memory 2 by the scalability ratio according to the first method described with reference to FIG. 4A. Also good. Instead, the CU setting unit 112b may determine a size selected from a plurality of size candidates equal to or smaller than the LCU size as the SCU size according to the second method described with reference to FIG. 4B. In the latter case, the CU setting unit 112b generates SCU size information indicating the selected SCU size.
- the CU setting unit 112b outputs the image data to the subtraction unit 13, the intra prediction unit 30b, and the inter prediction unit 40b for each LCU. Further, when generating the LCU size information or the SCU size information, the macroblock setting unit 112b outputs the generated size information to the lossless encoding unit 16b.
- FIG. 12 is a block diagram illustrating an example of a detailed configuration of the orthogonal transform units 14a and 14b illustrated in FIG.
- the orthogonal transform unit 14a includes a transform control unit 121a, a 4 ⁇ 4 transform unit 122a, an 8 ⁇ 8 transform unit 123a, and a size determination unit 126a.
- the orthogonal transform unit 14b includes a transform control unit 121b, a 4 ⁇ 4 transform unit 122b, an 8 ⁇ 8 transform unit 123b, a 16 ⁇ 16 transform unit 124b, a 32 ⁇ 32 transform unit 125b, and a size determination unit 126b.
- the transformation control unit 121a of the orthogonal transformation unit 14a sets a 4 ⁇ 4 pixel transformation block in a macro block for the prediction error data of the base layer, and sets each transformation block set.
- the orthogonal transformation is executed by the 4 ⁇ 4 conversion unit 122a.
- the transform control unit 121a sets a transform block of 8 ⁇ 8 pixels in the macroblock, and causes the 8 ⁇ 8 transform unit 123a to perform orthogonal transform for each set transform block.
- the conversion control unit 121a causes the size determination unit 126a to determine the optimum DCT size.
- the 4 ⁇ 4 conversion unit 122a performs 4 ⁇ 4 pixel two-dimensional DCT on the prediction error data for each conversion block set by the conversion control unit 121a. Then, the 4 ⁇ 4 conversion unit 122a outputs the conversion coefficient data to the size determination unit 126a.
- the 8 ⁇ 8 conversion unit 123a performs 8 ⁇ 8 pixel two-dimensional DCT on the prediction error data for each conversion block set by the conversion control unit 121a. Then, the 8 ⁇ 8 conversion unit 123a outputs the conversion coefficient data to the size determination unit 126a.
- the size determination unit 126a determines an optimal DCT size based on the conversion coefficient data input from the 4 ⁇ 4 conversion unit 122a and the 8 ⁇ 8 conversion unit 123a, and quantizes the conversion coefficient data corresponding to the optimal DCT size. To the unit 15. Further, the size determination unit 126a outputs DCT size information indicating an optimal DCT size to the lossless encoding unit 16a and the inverse orthogonal transform unit 22a, and causes the common memory 2 to buffer the DCT size information.
- the transformation control unit 121b of the orthogonal transformation unit 14b acquires DCT size information and a scalability ratio stored in the common memory 2. Then, the conversion control unit 121b sets a TU having one or more sizes determined using the DCT size and the scalability ratio in the LCU.
- the conversion control unit 121b sets a TU having a size determined by decisive decision by multiplying the DCT size by the scalability ratio in the enhancement layer LCU. . Then, the conversion control unit 121b predicts the conversion unit corresponding to the determined TU size among the 4 ⁇ 4 conversion unit 122b, the 8 ⁇ 8 conversion unit 123b, the 16 ⁇ 16 conversion unit 124b, and the 32 ⁇ 32 conversion unit 125b. Perform orthogonal transformation on the error data.
- the conversion control unit 121b adds TUs each having one or more TU sizes to be narrowed down based on the product of the DCT size and the scalability ratio according to the second method described with reference to FIG. 5B. May be set. Then, the transform control unit 121b performs orthogonal transform on the prediction error data to the corresponding transform unit among the 4 ⁇ 4 transform unit 122b, the 8 ⁇ 8 transform unit 123b, the 16 ⁇ 16 transform unit 124b, and the 32 ⁇ 32 transform unit 125b. Are executed respectively. When the second method is employed, the conversion control unit 121b causes the size determination unit 126b to determine the optimal TU size.
- the 4 ⁇ 4 conversion unit 122b performs a 2 ⁇ DCT of 4 ⁇ 4 pixels on the prediction error data.
- the 8 ⁇ 8 conversion unit 123b performs 8 ⁇ 8 pixel two-dimensional DCT on the prediction error data.
- the 16 ⁇ 16 conversion unit 124b performs 16 ⁇ 16 pixel two-dimensional DCT on the prediction error data.
- the 32 ⁇ 32 conversion unit 125b performs a 32 ⁇ 32 pixel two-dimensional DCT on the prediction error data.
- the size determination unit 126b selects an optimum TU size based on the conversion coefficient data input from the corresponding conversion units. judge. Then, the size determination unit 126b outputs transform coefficient data corresponding to the optimum TU size to the quantization unit 15. Further, the size determination unit 126b outputs TU size information indicating the optimal TU size to the lossless encoding unit 16b and the inverse orthogonal transform unit 22b.
- FIG. 13 is a block diagram illustrating an example of a detailed configuration of the intra prediction units 30a and 30b illustrated in FIG.
- the intra prediction unit 30a includes a prediction control unit 131a, a prediction unit 132a, and a mode determination unit 133a.
- the intra prediction unit 30b includes a prediction control unit 131b, a prediction unit 132b, and a mode determination unit 133b.
- the prediction control unit 131a of the intra prediction unit 30a controls the base layer intra prediction process. More specifically, the prediction control unit 131a sets prediction blocks having various sizes in the macroblock of the base layer, and causes the prediction unit 132a to perform intra prediction in various prediction modes. And the prediction control part 131a makes the mode determination part 133a determine the optimal prediction block size and prediction mode.
- the prediction unit 132a is a decoded image input from the frame memory 25 in various prediction modes (for example, DC prediction, horizontal prediction, vertical prediction, and plane prediction) for each prediction block set by the prediction control unit 131a. Predictive image data is generated using the data. Then, the prediction unit 132a outputs the generated predicted image data to the mode determination unit 133a.
- various prediction modes for example, DC prediction, horizontal prediction, vertical prediction, and plane prediction
- the mode determination unit 133a calculates a cost function value by comparing the predicted image data input from the prediction unit 132a with the original image data, and selects a combination of a prediction block size and a prediction mode that minimizes the cost function value. To do. Then, the mode determination unit 133a outputs information related to intra prediction including prediction mode information representing a combination of an optimal prediction block size and a prediction mode, a cost function value, and prediction image data to the selector 27. Further, the mode determination unit 133a causes the common memory 2 to buffer the predicted block size information.
- the prediction control unit 131b of the intra prediction unit 30b controls the enhancement layer intra prediction process. More specifically, the prediction control unit 131b sets one or more PUs in the enhancement layer LCU, and causes the prediction unit 132b to perform intra prediction in various prediction modes. And the prediction control part 131b makes the mode determination part 133b determine the optimal prediction mode.
- the prediction control unit 131b acquires base layer prediction block size information and scalability ratio stored in the common memory 2 in order to determine the PU size. And the prediction control part 131b determines PU size which should be set in LCU using a prediction block size and a scalability ratio.
- the prediction control unit 131b sets, in the LCU, a PU having a PU size determined by a decisive decision by multiplying the prediction block size by the scalability ratio according to the first method described with reference to FIG. 6A. Also good. Instead, the prediction control unit 131b determines PUs each having one or more PU sizes to be narrowed down based on the product of the prediction block size and the scalability ratio according to the second method described with reference to FIG. 6B. It may be set within.
- the prediction unit 132b decodes input from the frame memory 25 in various prediction modes (for example, DC prediction, angle prediction, plane prediction, and luminance-based color difference prediction) for each PU set by the prediction control unit 131b. Predictive image data is generated using the image data. Then, the prediction unit 132b outputs the generated predicted image data to the mode determination unit 133b.
- various prediction modes for example, DC prediction, angle prediction, plane prediction, and luminance-based color difference prediction
- the mode determination unit 133b calculates the cost function value by comparing the predicted image data input from the prediction unit 132b with the original image data, and selects the combination of the PU size and the prediction mode that minimizes the cost function value. . Then, the mode determination unit 133b outputs information related to intra prediction including prediction mode information, cost function values, and predicted image data to the selector 27.
- the information generated by the mode determination unit 133b may include PU size information as illustrated in FIG. 6B.
- FIG. 14 is a block diagram illustrating an example of a detailed configuration of the inter prediction units 40a and 40b illustrated in FIG.
- the inter prediction unit 40a includes a prediction control unit 141a, a prediction unit 142a, and a mode determination unit 143a.
- the inter prediction unit 40b includes a prediction control unit 141b, a prediction unit 142b, and a mode determination unit 143b.
- the prediction control unit 141a of the inter prediction unit 40a controls base layer inter prediction processing. More specifically, the prediction control unit 141a sets prediction blocks having various sizes in the macroblock of the base layer. In addition, the prediction control unit 141a sets a reference image for each prediction block. Then, the prediction control unit 141a causes the prediction unit 142a to perform inter prediction in various prediction modes. And the prediction control part 141a makes the mode determination part 143a determine the optimal prediction block size and prediction mode.
- the prediction unit 142a calculates a motion vector for each prediction block set by the prediction control unit 141a, and generates predicted image data using the calculated motion vector and reference image data. Then, the predicting unit 142a outputs the motion vector information and the predicted image data to the mode determining unit 143a.
- the mode determination unit 143a calculates a cost function value by comparing the predicted image data input from the prediction unit 142a with the original image data, and selects a combination of a prediction block size and a prediction mode that minimizes the cost function value. To do. Then, the mode determination unit 143a generates prediction block size information, prediction mode information, and motion information (motion vector information and reference image information) according to the selected optimal combination. The mode determination unit 143a outputs the information regarding the inter prediction, the cost function value, and the predicted image data to the selector 27. Further, the mode determination unit 143a causes the common memory 2 to buffer the prediction block size information (which may include the sub macroblock type).
- the prediction control unit 141b of the inter prediction unit 40b controls enhancement layer inter prediction processing. More specifically, the prediction control unit 141b sets one or more PUs in the enhancement layer LCU, and causes the prediction unit 142b to perform inter prediction. Then, the prediction control unit 141b causes the mode determination unit 143b to determine an optimal prediction mode.
- the prediction control unit 141b acquires the prediction block size information of the base layer stored in the common memory 2 and the scalability ratio in order to determine the PU size. And the prediction control part 141b determines PU size which should be set in LCU using a prediction block size and a scalability ratio.
- the prediction control unit 141b may set, in the LCU, a PU having a PU size that is determined by multiplying the prediction block size by the scalability ratio. Instead, the prediction control unit 141b may set PUs each having one or more PU sizes narrowed down based on the product of the prediction block size and the scalability ratio in the LCU. Further, the prediction control unit 141b may set, in the LCU, PUs each having one or more PU sizes to be narrowed down depending on whether a sub macroblock type exists for a corresponding prediction block in the base layer. .
- the prediction unit 142b calculates a motion vector for each PU set by the prediction control unit 141b, and generates predicted image data using the calculated motion vector and reference image data. Then, the predicting unit 142b outputs the motion vector information and the predicted image data to the mode determining unit 143b.
- the mode determination unit 143b calculates the cost function value by comparing the predicted image data input from the prediction unit 142b with the original image data, and selects the combination of the PU size and the prediction mode that minimizes the cost function value. . And the mode determination part 143b produces
- the mode determination unit 143b outputs the information regarding the inter prediction, the cost function value, and the predicted image data to the selector 27.
- the information generated by the mode determination unit 143b may include PU size information indicating the PU size selected from the narrowed down PU sizes.
- FIG. 15A is a flowchart showing a first example of the flow of block setting processing in the enhancement layer during encoding.
- the block setting process shown in FIG. 15A includes the first method for setting the LCU size described using FIG. 3A and the first method for setting the SCU size described using FIG. 4A. Processing according to the combination.
- the setting control unit 111b of the block setting unit 12b for the enhancement layer acquires block size information indicating the macroblock size and the sub macroblock size of the base layer from the common memory 2 (step S110a).
- the setting control unit 111b acquires a scalability ratio between the base layer and the enhancement layer (step S111).
- the CU setting unit 112b determines the enhancement layer LCU size by multiplying the macroblock size indicated by the block size information by the scalability ratio (step S112a). Further, the CU setting unit 112b determines the SCU size of the enhancement layer by a decisive decision by multiplying the sub-macro block size indicated by the block size information by the scalability ratio (step S114a).
- the CU setting unit 112b sets an LCU having the LCU size determined in step S112a in the enhancement layer (step S115a).
- segmentation from each LCU to CU may be determined according to the result of orthogonal transformation, intra prediction, and inter prediction.
- the lossless encoding unit 16b generates a division flag indicating the block division based on the LCU size and the SCU size determined by the CU setting unit 112b (step S117).
- FIG. 15B is a flowchart illustrating a second example of the flow of block setting processing in the enhancement layer during encoding.
- the block setting process shown in FIG. 15B includes the second method for setting the LCU size described with reference to FIG. 3B and the second method for setting the SCU size described with reference to FIG. 4B. Processing according to the combination.
- the setting control unit 111b of the block setting unit 12b for the enhancement layer acquires block size information indicating the macroblock size of the base layer from the common memory 2 (step S110b).
- the setting control unit 111b acquires a scalability ratio between the base layer and the enhancement layer (step S111).
- the CU setting unit 112b determines one or more candidates for the enhancement layer LCU size based on the product of the macroblock size and the scalability ratio (step S112b).
- the CU setting unit 112b selects an LCU size to be set from the narrowed-down LCU size candidates (step S113). Further, the CU setting unit 112b selects the SCU size to be set from one or more candidates of the SCU size equal to or smaller than the LCU size selected in step S113 (step S114b).
- the CU setting unit 112b sets the LCU having the LCU size selected in step S113 in the enhancement layer (step S115b). Further, the CU setting unit 112b generates parameters indicating the selected LCU size and SCU size (step S116).
- the parameters generated here are encoded by the lossless encoding unit 16b and inserted into, for example, the SPS.
- the block division from each LCU into CUs can be determined according to the results of orthogonal transform, intra prediction and inter prediction. Then, the lossless encoding unit 16b generates a division flag indicating the block division based on the LCU size and the SCU size selected by the CU setting unit 112b (step S117).
- FIG. 16A is a flowchart illustrating a first example of the flow of orthogonal transform processing in the enhancement layer during encoding.
- the orthogonal transform process illustrated in FIG. 16A is a process according to the first method for setting the TU size described with reference to FIG. 5A.
- the transformation control unit 121b of the orthogonal transformation unit 14b for the enhancement layer acquires DCT size information indicating the DCT size set in the base layer from the common memory 2 (step S120).
- the conversion control unit 121b acquires a scalability ratio between the base layer and the enhancement layer (step S121).
- the transformation control unit 121b determines the size of the TU in the enhancement layer corresponding to the transformation block in the base layer by multiplying the DCT size indicated by the DCT size information by the scalability ratio (step) S122a). Then, the conversion control unit 121b sets a TU having the determined TU size in the enhancement layer.
- the conversion unit corresponding to the TU size determined in step S122a is subjected to conversion control.
- Orthogonal transformation is executed for the TU set by the unit 121b (step S123a).
- the transform unit outputs transform coefficient data obtained as a result of the orthogonal transform to the quantization unit 15 (step S125a).
- FIG. 16B is a flowchart illustrating a second example of the flow of orthogonal transform processing in the enhancement layer during encoding.
- the orthogonal transform process illustrated in FIG. 16B is a process according to the second method for setting the TU size described with reference to FIG. 5B.
- the transform control unit 121b of the orthogonal transform unit 14b for the enhancement layer acquires DCT size information indicating the DCT size set in the base layer from the common memory 2 (step S120).
- the conversion control unit 121b acquires a scalability ratio between the base layer and the enhancement layer (step S121).
- the transformation control unit 121b determines one or more TU size candidates for the TUs in the enhancement layer corresponding to the transformed blocks in the base layer, based on the product of the DCT size and the scalability ratio (step S122b). And the conversion control part 121b sets TU which has TU size as a determined candidate in an enhancement layer.
- the conversion unit corresponding to the TU size determined in step S122b is the TU size.
- orthogonal transformation is executed (step S123b).
- the size determining unit 126b determines the optimum TU size from one or more TU size candidates by comparing the transform coefficient data obtained as a result of the orthogonal transform (step S124). Then, the size determination unit 126b outputs transform coefficient data corresponding to the optimum TU size to the quantization unit 15 (step S125b). In addition, the size determination unit 126b generates a parameter indicating the optimal TU size, and outputs the generated parameter to the lossless encoding unit 16b and the inverse orthogonal transform unit 22b (step S126).
- FIG. 17A is a flowchart showing a first example of the flow of intra prediction processing in the enhancement layer at the time of encoding.
- the intra prediction process illustrated in FIG. 17A is a process according to the first method for setting the PU size described with reference to FIG. 6A.
- the prediction control unit 131b of the intra prediction unit 30b for the enhancement layer acquires prediction block size information indicating the prediction block size set in the base layer from the common memory 2 (step S130). ).
- the prediction control unit 131b acquires a scalability ratio between the base layer and the enhancement layer (step S131).
- the prediction control unit 131b determines the size of the PU in the enhancement layer corresponding to the prediction block in the base layer by multiplying the prediction block size indicated by the prediction block size information by the scalability ratio. (Step S132a). Then, the prediction control unit 131b sets a PU having the determined PU size in the enhancement layer.
- the prediction unit 132b performs intra prediction in various prediction modes for the PU set by the prediction control unit 131b (step S133a).
- the mode determination unit 133b selects an optimal prediction mode by comparing the predicted image data input from the prediction unit 132b with the original image data (step S134a).
- the mode determination part 133b produces
- FIG. 17B is a flowchart illustrating a second example of the flow of intra prediction processing in the enhancement layer during encoding.
- the intra prediction process illustrated in FIG. 17B is a process according to the second method for setting the PU size described with reference to FIG. 6B.
- the prediction control unit 131b of the intra prediction unit 30b for the enhancement layer acquires prediction block size information indicating the prediction block size set in the base layer from the common memory 2 (step S130). ).
- the prediction control unit 131b acquires a scalability ratio between the base layer and the enhancement layer (step S131).
- the prediction control unit 131b determines one or more PU size candidates for PUs in the enhancement layer corresponding to the prediction block in the base layer with reference to the product of the prediction block size and the scalability ratio (Ste S132b). And the prediction control part 131b sets PU which has PU size as a determined candidate in an enhancement layer.
- the prediction unit 132b performs intra prediction in various prediction modes for each PU having a PU size as a candidate (step S133b).
- the mode determination unit 133b selects the optimal PU size and prediction mode by comparing the predicted image data input from the prediction unit 132b with the original image data (step S134b).
- the mode determination part 133b produces
- FIG. 18A is a flowchart illustrating a first example of the flow of inter prediction processing in the enhancement layer during encoding.
- the inter prediction process illustrated in FIG. 18A is a process in which the first method for setting the PU size described with reference to FIG. 6A is applied to inter prediction.
- the prediction control unit 141b of the inter prediction unit 40b for the enhancement layer acquires prediction block size information indicating the prediction block size set in the base layer from the common memory 2 (step S140a).
- the prediction control unit 141b acquires a scalability ratio between the base layer and the enhancement layer (step S141).
- the prediction control unit 141b determines the size of the PU in the enhancement layer corresponding to the prediction block in the base layer by multiplying the prediction block size indicated by the prediction block size information by the scalability ratio. (Step S142a). Then, the prediction control unit 141b sets a PU having the determined PU size in the enhancement layer.
- the prediction unit 142b performs inter prediction in various prediction modes for the PU set by the prediction control unit 141b (step S143a).
- the mode determination unit 143b selects the optimal prediction mode by comparing the predicted image data input from the prediction unit 142b with the original image data (step S144a).
- the mode determination part 143b produces
- FIG. 18B is a flowchart illustrating a second example of the flow of inter prediction processing in the enhancement layer during encoding.
- the inter prediction process illustrated in FIG. 18B is a process according to the third method for setting the PU size described with reference to FIG. 7B.
- the prediction control unit 141b of the inter prediction unit 40b for the enhancement layer obtains from the common memory 2 a sub macroblock type indicating whether division into sub macroblocks is used in the base layer. (Step S140b). Next, the prediction control unit 141b acquires a scalability ratio between the base layer and the enhancement layer (step S141).
- the prediction control unit 141b refers to the sub-macroblock type, and determines whether the prediction block in the base layer is divided into sub-macroblocks for the PU in the enhancement layer corresponding to the prediction block.
- One or more PU size candidates are determined (step S142b).
- the prediction control part 141b sets PU which has PU size as a determined candidate in an enhancement layer.
- the prediction unit 142b performs inter prediction in various prediction modes for each PU having a PU size as a candidate (step S143b).
- the mode determination unit 143b selects an optimal PU size and prediction mode by comparing the predicted image data input from the prediction unit 142b with the original image data (step S144b).
- the mode determination part 143b produces
- FIG. 19 is a block diagram illustrating an example of the configuration of the first decoding unit 6a and the second decoding unit 6b illustrated in FIG.
- the first decoding unit 6a includes a lossless decoding unit 61a, a block setting unit 62a, an inverse quantization unit 63, an inverse orthogonal transform unit 64a, an addition unit 65, a deblock filter 66, a rearrangement buffer 67, D / A (Digital to Analogue) conversion unit 68, frame memory 69, selectors 70 and 71, intra prediction unit 80a, and inter prediction unit 90a.
- D / A Digital to Analogue
- the second decoding unit 6b includes a lossless decoding unit 61a, a block setting unit 62a, an inverse orthogonal transform unit 64a, an intra prediction unit 80a, and an inter prediction unit 90a instead of a lossless decoding unit 61b, a block setting unit 62b, and an inverse orthogonal transform unit. 64b, an intra prediction unit 80b, and an inter prediction unit 90b.
- the lossless decoding unit 61a decodes the base layer encoded stream input via the transmission path in accordance with the encoding method used at the time of encoding, and generates base layer quantized data. Further, the lossless decoding unit 61a decodes information multiplexed in the header area of the encoded stream.
- the information decoded by the lossless decoding unit 61a may include, for example, DCT size information, information related to intra prediction, and information related to inter prediction.
- the lossless decoding unit 61b decodes the enhancement layer encoded stream input via the transmission path in accordance with the encoding method used for encoding, and generates enhancement layer quantized data.
- the lossless decoding unit 61b decodes information multiplexed in the header area of the encoded stream.
- the information decoded by the lossless decoding unit 61b may include, for example, scalability ratio, block size information, division flag, information on intra prediction, and information on inter prediction.
- the block setting unit 62a sets a macroblock having a fixed size in the base layer. Then, for each set macroblock, the block setting unit 62a outputs quantized data to the inverse quantization unit 63, information related to intra prediction to the intra prediction unit 80a, and information related to inter prediction to the inter prediction unit 90a. .
- the macro block size is stored in advance by the common memory 7.
- the block setting unit 62b sets a CU in the enhancement layer according to the macroblock size set by the block setting unit 62a. More specifically, the block setting unit 62b first sets the LCU in the enhancement layer, and further recursively blocks the LCU according to the LCU size, the SCU size, and the partition flag, thereby allocating the CU in each LCU. Set.
- the block setting unit 62 b can determine the LCU size using the scalability ratio and the macroblock size stored in the common memory 7.
- the SCU size may be further determined by referring to a sub macroblock size that can be stored by the common memory 7.
- the block setting unit 62b outputs the quantized data to the inverse quantization unit 63, information related to intra prediction to the intra prediction unit 80b, and information related to inter prediction to the inter prediction unit 90b.
- the inverse quantization unit 63 inversely quantizes the quantized data input from the block setting unit 62a or 62b to generate transform coefficient data. Then, the inverse quantization unit 63 outputs the generated transform coefficient data to the inverse orthogonal transform unit 64a or 64b.
- the inverse orthogonal transform unit 64a sets a transform block in the macroblock according to the DCT size information decoded by the lossless decoding unit 61a, and performs inverse orthogonal transform on the transform coefficient data of the base layer input from the inverse quantization unit 63. Execute.
- the inverse orthogonal transform executed by the inverse orthogonal transform unit 64a may be, for example, an inverse discrete cosine transform (inverse DCT).
- the DCT size is 8 ⁇ 8 pixels or 4 ⁇ 4 pixels.
- the inverse orthogonal transform unit 64 a outputs prediction error data acquired by the inverse orthogonal transform process for each transform block to the addition unit 65. Further, the inverse orthogonal transform unit 64 a causes the common memory 7 to buffer DCT size information indicating the size of each set transform block.
- the inverse orthogonal transform unit 64b sets a TU in each CU set by the block setting unit 62b, and performs inverse orthogonal transform on the enhancement layer transform coefficient data input from the inverse quantization unit 63.
- the inverse orthogonal transform executed by the inverse orthogonal transform unit 64b may also be an inverse DCT.
- the size of the TU set by the inverse orthogonal transform unit 64b is 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, or 4 ⁇ 4 pixels.
- the inverse orthogonal transform unit 64 b can determine the TU size to be set in the enhancement layer using the DCT size information and the scalability ratio of the base layer stored in the common memory 7.
- the inverse orthogonal transform unit 64 b outputs transform coefficient data acquired by the orthogonal transform process for each TU to the adder unit 65.
- the addition unit 65 adds the prediction error data input from the inverse orthogonal transform unit 64a or 64b and the prediction image data input from the selector 71 to generate decoded image data. Then, the addition unit 65 outputs the generated decoded image data to the deblock filter 66 and the frame memory 69.
- the deblock filter 66 removes block distortion by filtering the decoded image data input from the adder 65, and outputs the filtered decoded image data to the rearrangement buffer 67 and the frame memory 69.
- the rearrangement buffer 67 generates a series of time-series image data by rearranging the images input from the deblocking filter 66. Then, the rearrangement buffer 67 outputs the generated image data to the D / A conversion unit 68.
- the D / A converter 68 converts the digital image data input from the rearrangement buffer 67 into an analog image signal. Then, the D / A conversion unit 68 displays an image by outputting an analog image signal to a display (not shown) connected to the image decoding device 60, for example.
- the frame memory 69 stores the decoded image data before filtering input from the adding unit 65 and the decoded image data after filtering input from the deblocking filter 66 using a storage medium.
- the selector 70 switches the output destination of the image data from the frame memory 69 between the intra prediction unit 80a or 80b and the inter prediction unit 90a or 90b for each block in the image. For example, when the intra prediction mode is designated by the parameter to be decoded, the selector 70 outputs the decoded image data before filtering supplied from the frame memory 69 to the intra prediction unit 80a or 80b as reference image data. Further, when the inter prediction mode is designated, the selector 70 outputs the decoded image data after filtering supplied from the frame memory 69 to the inter prediction unit 90a or 90b as reference image data.
- the selector 71 switches the output source of the predicted image data to be supplied to the adding unit 65 between the intra prediction unit 80a or 80b and the inter prediction unit 90a or 90b. For example, the selector 71 supplies the predicted image data output from the intra prediction unit 80a or 80b to the addition unit 65 when the intra prediction mode is designated by the parameter to be decoded. Further, when the inter prediction mode is designated, the selector 71 supplies the predicted image data output from the inter prediction unit 90a or 90b to the adding unit 65.
- the intra prediction unit 80a performs base layer intra prediction processing based on information related to intra prediction input from the block setting unit 62a for each macroblock and reference image data from the frame memory 69, and generates predicted image data. .
- the intra prediction unit 80a sets a prediction block in a macroblock according to the prediction block size information, and executes intra prediction according to the prediction mode information for each set prediction block.
- the size of the prediction block set by the intra prediction unit 80a is 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, or 4 ⁇ 4 pixels.
- the intra prediction unit 80a outputs the generated base layer predicted image data to the selector 71. Further, the intra prediction unit 80 a causes the common memory 7 to buffer the predicted block size information.
- the intra prediction unit 80b performs the intra prediction process of the enhancement layer based on the information related to intra prediction input for each LCU from the block setting unit 62b and the reference image data from the frame memory 69, and generates predicted image data. For example, the intra prediction unit 80b sets a PU in each CU, and executes intra prediction according to the prediction mode information for each set PU.
- the size of the PU set by the intra prediction unit 80b is 64 ⁇ 64 pixels, 32 ⁇ 32 pixels, 16 ⁇ 16 pixels, 8 ⁇ 8 pixels, or 4 ⁇ 4 pixels.
- the intra prediction unit 80b may determine the PU size to be set in the enhancement layer using the base layer prediction block size information and the scalability ratio stored in the common memory 7. Then, the intra prediction unit 80b outputs the generated predicted image data of the enhancement layer to the selector 71.
- the inter prediction unit 90a performs base layer inter prediction processing based on information related to inter prediction input for each macroblock from the block setting unit 62a and reference image data from the frame memory 69, and generates predicted image data. .
- the inter prediction unit 90a sets a prediction block in a macroblock according to prediction block size information, and performs inter prediction (motion compensation) using motion information for each set prediction block.
- the size of the prediction block set by the inter prediction unit 90a is one of the seven sizes shown in FIG. 7A.
- the inter prediction unit 90 a outputs the generated base layer predicted image data to the selector 71.
- the inter prediction unit 90 a causes the common memory 7 to buffer the predicted block size information.
- the predicted block size information may include a sub macroblock type.
- the inter prediction unit 90 b performs enhancement layer inter prediction processing based on information related to inter prediction input for each LCU from the block setting unit 62 b and reference image data from the frame memory 69, and generates predicted image data. For example, the inter prediction unit 90b sets PUs in each CU, and performs inter prediction using motion information for each set PU. The inter prediction unit 90b may determine the PU size to be set in the enhancement layer using the base layer prediction block size information and the scalability ratio stored in the common memory 7. Then, the inter prediction unit 90b outputs the generated predicted image data of the enhancement layer to the selector 71.
- the first decoding unit 6a executes the series of decoding processes described here for a series of image data of the base layer.
- the second decoding unit 6b performs the series of decoding processes described here on a series of image data of the enhancement layer.
- the enhancement layer decoding process may be repeated by the number of enhancement layers.
- FIG. 20 is a block diagram illustrating an example of a detailed configuration of the block setting units 62a and 62b illustrated in FIG.
- the block setting unit 62a includes a setting control unit 161a and a macroblock setting unit 162a.
- the block setting unit 62b includes a setting control unit 161b, a size setting unit 162b, and a CU setting unit 163b.
- the setting control unit 161a of the block setting unit 62a acquires a fixed macroblock size stored in advance in the common memory 7, and sets a macroblock having the acquired size as a macroblock.
- the setting unit 162a is instructed.
- the macroblock setting unit 162a sets one or more macroblocks in the base layer in response to an instruction from the setting control unit 161a. Then, the macroblock setting unit 162a, for each set macroblock, the quantized data to the inverse quantization unit 63, information about intra prediction to the intra prediction unit 80a, and information about inter prediction to the inter prediction unit 90a, respectively. Output.
- the setting control unit 161b of the block setting unit 62b acquires the macroblock size stored in the common memory 7 and the scalability ratio between the base layer and the enhancement layer.
- the scalability ratio may be directly indicated by a parameter decoded by the lossless decoding unit 61b, or may be calculated from two layers of resolution data. Then, the setting control unit 161b instructs the size setting unit 162b to set the LCU size and the SCU size determined using the macroblock size and the scalability ratio.
- the size setting unit 162b sets the LCU size and the SCU size in the enhancement layer in response to an instruction from the setting control unit 161b.
- the size setting unit 162b may determine the LCU size in a determined manner by multiplying the macroblock size by the scalability ratio according to the first method described with reference to FIG. 3A. Instead, the size setting unit 162b is decoded by the lossless decoding unit 61b after narrowing down the size candidates based on the product of the macroblock size and the scalability ratio according to the second method described with reference to FIG. 3B.
- the LCU size may be selected with reference to the LCU size information.
- the size setting unit 162b determines the SCU size by deterministically by multiplying the sub macroblock size stored in advance by the common memory 7 by the scalability ratio according to the first method described with reference to FIG. 4A. Also good. Instead, the size setting unit 162b refers to the SCU size information decoded by the lossless decoding unit 61b from a plurality of size candidates equal to or smaller than the LCU size according to the second method described with reference to FIG. 4B. May be selected.
- the CU setting unit 163b recursively divides the LCU into blocks according to the LCU size and SCU size set by the size setting unit 162b, and the division flag decoded by the lossless decoding unit 61b, so that the CU is included in each LCU. Set. Then, for each LCU, the CU setting unit 163b outputs quantized data to the inverse quantization unit 63, information related to intra prediction to the intra prediction unit 80b, and information related to inter prediction to the inter prediction unit 90b.
- FIG. 21 is a block diagram illustrating an example of a detailed configuration of the inverse orthogonal transform units 64a and 64b illustrated in FIG.
- the inverse orthogonal transform unit 64a includes a transform control unit 171a, a 4 ⁇ 4 transform unit 172a, and an 8 ⁇ 8 transform unit 173a.
- the inverse orthogonal transform unit 64b includes a transform control unit 171b, a 4 ⁇ 4 transform unit 172b, an 8 ⁇ 8 transform unit 173b, a 16 ⁇ 16 transform unit 174b, and a 32 ⁇ 32 transform unit 175b.
- the transform control unit 171a of the inverse orthogonal transform unit 64a sets a transform block having a DCT size indicated by the DCT size information decoded by the lossless decoding unit 61a in a macroblock. . Then, the transform control unit 171a converts the base layer transform coefficient data input from the inverse quantization unit 63 into the transform unit corresponding to the set DCT size among the 4 ⁇ 4 transform unit 172a and the 8 ⁇ 8 transform unit 173a. Inverse orthogonal transformation is performed on. In addition, the conversion control unit 171a causes the common memory 7 to buffer DCT size information indicating the size of each conversion block.
- the 4 ⁇ 4 transform unit 172a When the transform block having the size of 4 ⁇ 4 pixels is set, the 4 ⁇ 4 transform unit 172a performs 4 ⁇ 4 pixel two-dimensional inverse DCT on transform coefficient data of the transform block. Then, the 4 ⁇ 4 conversion unit 172a outputs the prediction error data to the addition unit 65.
- the 8 ⁇ 8 transform unit 173a When a transform block having a size of 8 ⁇ 8 pixels is set, the 8 ⁇ 8 transform unit 173a performs 8 ⁇ 8 pixel two-dimensional inverse DCT on transform coefficient data of the transform block. Then, the 8 ⁇ 8 conversion unit 173a outputs the prediction error data to the addition unit 65.
- the transformation control unit 171b of the inverse orthogonal transformation unit 64b acquires DCT size information and scalability ratio stored in the common memory 7. Then, the conversion control unit 171b sets a TU having a size determined by using the DCT size and the scalability ratio in each CU of the enhancement layer.
- the conversion control unit 171b may determine the TU size in a determined manner by multiplying the DCT size by the scalability ratio according to the first method described with reference to FIG. 5A. Instead, the conversion control unit 171b performs decoding by the lossless decoding unit 61b after narrowing down the size candidates based on the product of the DCT size and the scalability ratio according to the second method described with reference to FIG. 5B.
- the TU size may be selected with reference to the TU size information.
- the conversion control unit 171a reverses the conversion unit corresponding to the set TU size among the 4 ⁇ 4 conversion unit 172b, the 8 ⁇ 8 conversion unit 173b, the 16 ⁇ 16 conversion unit 174b, and the 32 ⁇ 32 conversion unit 175b.
- the inverse orthogonal transform is performed on the enhancement layer transform coefficient data input from the quantization unit 63.
- the 4 ⁇ 4 conversion unit 172b When the TU having the size of 4 ⁇ 4 pixels is set, the 4 ⁇ 4 conversion unit 172b performs the 4 ⁇ 4 pixel two-dimensional inverse DCT on the conversion coefficient data of the TU. Then, the 4 ⁇ 4 conversion unit 172b outputs the prediction error data to the addition unit 65.
- the 8 ⁇ 8 conversion unit 173b When a TU having a size of 8 ⁇ 8 pixels is set, the 8 ⁇ 8 conversion unit 173b performs 8 ⁇ 8 pixel two-dimensional inverse DCT on the conversion coefficient data of the TU. Then, the 8 ⁇ 8 conversion unit 173b outputs the prediction error data to the addition unit 65.
- the 16 ⁇ 16 conversion unit 174b When a TU having a size of 16 ⁇ 16 pixels is set, the 16 ⁇ 16 conversion unit 174b performs 16 ⁇ 16 pixel two-dimensional inverse DCT on the conversion coefficient data of the TU. Then, the 16 ⁇ 16 conversion unit 174b outputs the prediction error data to the addition unit 65.
- the 32 ⁇ 32 conversion unit 175b When a TU having a size of 32 ⁇ 32 pixels is set, the 32 ⁇ 32 conversion unit 175b performs a 32 ⁇ 32 pixel two-dimensional inverse DCT on the conversion coefficient data of the TU. Then, the 32 ⁇ 32 conversion unit 175b outputs the prediction error data to the addition unit 65.
- FIG. 22 is a block diagram illustrating an example of a detailed configuration of the intra prediction units 80a and 80b illustrated in FIG.
- the intra prediction unit 80a includes a prediction control unit 181a, a mode acquisition unit 182a, and a prediction unit 183a.
- the intra prediction unit 80b includes a prediction control unit 181b, a mode acquisition unit 182b, and a prediction unit 183b.
- the prediction control unit 181a of the intra prediction unit 80a controls the base layer intra prediction process. More specifically, the prediction control unit 181a sets a prediction block having a size indicated by the prediction block size information decoded by the lossless decoding unit 61a in the macroblock.
- the mode acquisition unit 182a acquires prediction mode information decoded by the lossless decoding unit 61a. Then, the prediction control unit 181a causes the prediction unit 183a to perform intra prediction in the prediction mode indicated by the prediction mode information. Further, the prediction control unit 181a causes the common memory 7 to buffer prediction block size information indicating the size of each prediction block.
- the prediction unit 183a generates prediction image data using the decoded image data input from the frame memory 69 in the prediction mode indicated by the prediction mode information for each prediction block set by the prediction control unit 181a. Then, the prediction unit 183a outputs the generated predicted image data to the addition unit 65.
- the prediction control unit 181b of the intra prediction unit 80b controls enhancement layer intra prediction processing. More specifically, the prediction control unit 181b sets a PU in each CU of the enhancement layer. The prediction control unit 181b acquires the scalability ratio and the base layer prediction block size information stored in the common memory 7 in order to determine the PU size. And the prediction control part 181b determines PU size which should be set using a prediction block size and a scalability ratio.
- the prediction control unit 181b may determine the PU size by multiplying the prediction block size by the scalability ratio according to the first method described with reference to FIG. 6A. Instead, the prediction control unit 181b narrows down the size candidates based on the product of the prediction block size and the scalability ratio according to the second method described with reference to FIG. 6B, and then is decoded by the lossless decoding unit 61b.
- the PU size may be selected with reference to the PU size information.
- the mode acquisition unit 182b acquires prediction mode information decoded by the lossless decoding unit 61b.
- the prediction unit 183b generates predicted image data using the decoded image data input from the frame memory 69 in the prediction mode indicated by the prediction mode information for each PU set by the prediction control unit 181b. Then, the prediction unit 183b outputs the generated predicted image data to the addition unit 65.
- FIG. 23 is a block diagram illustrating an example of a detailed configuration of the inter prediction units 90a and 90b illustrated in FIG.
- the inter prediction unit 90a includes a prediction control unit 191a, an information acquisition unit 192a, and a prediction unit 193a.
- the inter prediction unit 90b includes a prediction control unit 191b, an information acquisition unit 192b, and a prediction unit 193b.
- the prediction control unit 191a of the inter prediction unit 90a controls base layer inter prediction processing. More specifically, the prediction control unit 191a sets a prediction block having a size indicated by the prediction block size information decoded by the lossless decoding unit 61a in the macroblock. In addition, the information acquisition unit 192a acquires prediction mode information and motion information decoded by the lossless decoding unit 61a. Then, the prediction control unit 191a causes the prediction unit 193a to perform inter prediction in the prediction mode indicated by the prediction mode information. Further, the prediction control unit 191a causes the common memory 7 to buffer prediction block size information indicating the size of each prediction block (which may include a sub macroblock type).
- the prediction unit 193a generates prediction image data for each prediction block set by the prediction control unit 191a using the motion information and the decoded image data input from the frame memory 69 in the prediction mode indicated by the prediction mode information. . Then, the prediction unit 193a outputs the generated predicted image data to the addition unit 65.
- the prediction control unit 191b of the inter prediction unit 90b controls enhancement layer inter prediction processing. More specifically, the prediction control unit 191b sets a PU in each CU of the enhancement layer. In order to determine the PU size, the prediction control unit 191b acquires the scalability ratio and the base layer prediction block size information stored in the common memory 7. And the prediction control part 191b determines PU size which should be set using a prediction block size and a scalability ratio.
- the prediction control unit 191b may determine the PU size by multiplying the prediction block size by the scalability ratio. Instead, the prediction control unit 191b selects the PU size by referring to the PU size information decoded by the lossless decoding unit 61b after narrowing down the size candidates based on the product of the prediction block size and the scalability ratio. May be. In addition, the prediction control unit 141b refers to the PU size information decoded by the lossless decoding unit 61b after narrowing down the size candidates according to whether the sub-macroblock type exists for the corresponding prediction block in the base layer. The PU size may be selected.
- the information acquisition unit 192b acquires prediction mode information and motion information decoded by the lossless decoding unit 61b. For each PU set by the prediction control unit 191b, the prediction unit 193b generates predicted image data using the decoded image data input from the frame memory 69 according to the motion vector information and reference image information included in the motion information. . Then, the predicting unit 193b outputs the generated predicted image data to the adding unit 65.
- FIG. 24A is a flowchart illustrating a first example of the flow of block setting processing in the enhancement layer during decoding.
- the block setting process shown in FIG. 24A includes the first method for setting the LCU size described with reference to FIG. 3A and the first method for setting the SCU size described with reference to FIG. 4A. Processing according to the combination.
- the setting control unit 161b of the block setting unit 62b for the enhancement layer acquires block size information indicating the macroblock size and the sub macroblock size of the base layer (step S160a).
- the setting control unit 161b acquires a scalability ratio between the base layer and the enhancement layer (step S161).
- the size setting unit 162b multiplies the macroblock size indicated by the block size information by the scalability ratio, thereby determining the enhancement layer LCU size (step S164a). Further, the size setting unit 162b multiplies the sub macroblock size indicated by the block size information by the scalability ratio, thereby determining the enhancement layer SCU size (step S166a).
- the LCU size and SCU size determined in step S164a and step S166a may be set for each sequence in the enhancement layer.
- the size setting unit 162b sets the LCU having the LCU size determined in step S164a in the enhancement layer (step S167a).
- the CU setting unit 163b recursively divides the LCU into blocks according to the LCU size and the SCU size set by the size setting unit 162b and the division flag decoded by the lossless decoding unit 61b.
- the CU is set to (step S168).
- FIG. 24B is a flowchart illustrating a second example of the flow of block setting processing in the enhancement layer during decoding.
- the block setting process shown in FIG. 24B includes the second method for setting the LCU size described with reference to FIG. 3B and the second method for setting the SCU size described with reference to FIG. 4B. Processing according to the combination.
- the setting control unit 161b of the block setting unit 62b for the enhancement layer acquires block size information indicating the macroblock size of the base layer (step S160b).
- the setting control unit 161b acquires a scalability ratio between the base layer and the enhancement layer (step S161).
- the setting control unit 161b acquires parameters indicating the LCU size and the SCU size decoded by the lossless decoding unit 61b (step S162b).
- the size setting unit 162b determines one or more candidates for the LCU size based on the product of the macroblock size and the scalability ratio (step S163b). Next, the size setting unit 162b selects the LCU size specified by the parameter decoded by the lossless decoding unit 61b from among the candidates for the LCU size (step S164b). Further, the size setting unit 162b determines one or more SCU size candidates having a size equal to or smaller than the selected LCU size (step S165b). Next, the size setting unit 162b selects the SCU size specified by the parameter decoded by the lossless decoding unit 61b from among the SCU size candidates (step S164b). The LCU size and SCU size selected in step S164b and step S166b may be set for each sequence in the enhancement layer.
- the size setting unit 162b sets the LCU having the LCU size selected in step S164b in the enhancement layer (step S167b).
- the CU setting unit 163b recursively divides the LCU into blocks according to the LCU size and the SCU size set by the size setting unit 162b and the division flag decoded by the lossless decoding unit 61b.
- the CU is set to (step S168).
- FIG. 25A is a flowchart illustrating a first example of the flow of inverse orthogonal transform processing in the enhancement layer during decoding.
- the inverse orthogonal transform process illustrated in FIG. 25A is a process according to the first method for setting the TU size described with reference to FIG. 5A.
- the transformation control unit 171b of the inverse orthogonal transformation unit 64b for the enhancement layer acquires DCT size information indicating the DCT size of the base layer from the common memory 7 (step S170).
- the conversion control unit 171b obtains a scalability ratio between the base layer and the enhancement layer (step S171).
- the conversion control unit 171b multiplies the DCT size by the scalability ratio to determine the enhancement layer TU size by a decisive rule (step S174a).
- the conversion control unit 171b sets a TU having the determined TU size in each CU of the enhancement layer (step S175a).
- the conversion unit corresponding to the TU size determined by the conversion control unit 171b is: Inverse orthogonal transformation is executed for the set TU (step S176).
- FIG. 25B is a flowchart illustrating a second example of the flow of inverse orthogonal transform processing in the enhancement layer during decoding.
- the inverse orthogonal transform process illustrated in FIG. 25B is a process according to the second method for setting the TU size described with reference to FIG. 5B.
- the transform control unit 171b of the inverse orthogonal transform unit 64b for the enhancement layer acquires DCT size information indicating the DCT size of the base layer from the common memory 7 (step S170).
- the conversion control unit 171b obtains a scalability ratio between the base layer and the enhancement layer (step S171).
- the conversion control unit 171b obtains TU size information decoded by the lossless decoding unit 61b (step S172).
- the conversion control unit 171b determines one or more candidates for the TU size based on the product of the DCT size and the scalability ratio (step S173). Next, the conversion control unit 171b selects a TU size specified by the TU size information from the TU size candidates (step S174b). Next, the conversion control unit 171b sets a TU having the selected TU size in each CU of the enhancement layer (step S175b).
- the conversion unit corresponding to the TU size selected by the conversion control unit 171b is: Inverse orthogonal transformation is executed for the set TU (step S176).
- FIG. 26A is a flowchart illustrating a first example of the flow of intra prediction processing in the enhancement layer during decoding.
- the intra prediction process illustrated in FIG. 26A is a process according to the first method for setting the PU size described with reference to FIG. 6A.
- the prediction control unit 181b of the intra prediction unit 80b for the enhancement layer acquires prediction block size information indicating the prediction block size of the base layer from the common memory 7 (step S180).
- the prediction control unit 181b obtains a scalability ratio between the base layer and the enhancement layer (step S181).
- the prediction control unit 181b multiplies the prediction block size by the scalability ratio, thereby determining the PU size of the enhancement layer by a decisive action (step S184a).
- the prediction control unit 181b sets a PU having the determined PU size in each CU of the enhancement layer (step S185a).
- the mode acquisition unit 182b acquires the prediction mode information decoded by the lossless decoding unit 61b for the PU set by the prediction control unit 181b (step S186). And the prediction part 183b performs intra prediction according to the prediction mode shown by prediction mode information about PU set by the prediction control part 181b (step S187).
- FIG. 26B is a flowchart illustrating a second example of the flow of the intra prediction process in the enhancement layer at the time of decoding.
- the intra prediction process illustrated in FIG. 26B is a process according to the second method for setting the PU size described with reference to FIG. 6B.
- the prediction control unit 181b of the intra prediction unit 80b for the enhancement layer acquires prediction block size information indicating the prediction block size of the base layer from the common memory 7 (step S180).
- the prediction control unit 181b acquires a scalability ratio between the base layer and the enhancement layer (step S181).
- the prediction control unit 181b acquires PU size information decoded by the lossless decoding unit 61b (step S182).
- the prediction control unit 181b determines one or more PU size candidates based on the product of the prediction block size and the scalability ratio (step S183). Next, the prediction control unit 181b selects a PU size specified by the PU size information from among PU size candidates (step S184b). Next, the prediction control unit 181b sets a PU having the selected PU size in each CU of the enhancement layer (step S185b).
- the mode acquisition unit 182b acquires the prediction mode information decoded by the lossless decoding unit 61b for the PU set by the prediction control unit 181b (step S186). And the prediction part 183b performs intra prediction according to the prediction mode shown by prediction mode information about PU set by the prediction control part 181b (step S187).
- FIG. 27A is a flowchart illustrating a first example of the flow of inter prediction processing in the enhancement layer during decoding.
- the inter prediction process illustrated in FIG. 27A is a process in which the first method for setting the PU size described with reference to FIG. 6A is applied to inter prediction.
- the prediction control unit 191b of the inter prediction unit 90b for the enhancement layer acquires prediction block size information indicating the prediction block size of the base layer from the common memory 7 (step S190a).
- the prediction control unit 191b acquires a scalability ratio between the base layer and the enhancement layer (step S191).
- the prediction control unit 191b multiplies the prediction block size by the scalability ratio, thereby determining the PU size of the enhancement layer (step S194a).
- the prediction control unit 191b sets a PU having the determined PU size in each CU of the enhancement layer (step S195a).
- the information acquisition unit 192b acquires the prediction mode information and motion information decoded by the lossless decoding unit 61b for the PU set by the prediction control unit 191b (step S196). And the prediction part 193b performs inter prediction using motion information according to the prediction mode shown by prediction mode information about PU set by the prediction control part 191b (step S197).
- FIG. 27B is a flowchart illustrating a second example of the flow of inter prediction processing in the enhancement layer during decoding.
- the inter prediction process illustrated in FIG. 27B is a process according to the third method for setting the PU size described with reference to FIG. 7B.
- the prediction control unit 191b of the inter prediction unit 90b for the enhancement layer receives the prediction block size information including the sub-macroblock type specified for the corresponding prediction block of the base layer in the common memory 7. (Step S190b). Next, the prediction control unit 191b acquires a scalability ratio between the base layer and the enhancement layer (step S191). Next, the prediction control unit 191b obtains PU size information decoded by the lossless decoding unit 61b (step S192).
- the prediction control unit 191b determines one or more candidates for the PU size by referring to the sub macroblock type (step S193). Next, the prediction control unit 191b selects a PU size specified by the PU size information from among PU size candidates (step S194b). Next, the prediction control unit 191b sets a PU having the selected PU size in each CU of the enhancement layer (step S195b).
- the information acquisition unit 192b acquires the prediction mode information and motion information decoded by the lossless decoding unit 61b for the PU set by the prediction control unit 191b (step S196). And the prediction part 193b performs inter prediction using motion information according to the prediction mode shown by prediction mode information about PU set by the prediction control part 191b (step S197).
- the image encoding device 10 and the image decoding device 60 are a transmitter or a receiver in satellite broadcasting, cable broadcasting such as cable TV, distribution on the Internet, and distribution to terminals by cellular communication,
- the present invention can be applied to various electronic devices such as a recording device that records an image on a medium such as an optical disk, a magnetic disk, and a flash memory, or a playback device that reproduces an image from these storage media.
- a recording device that records an image on a medium such as an optical disk, a magnetic disk, and a flash memory
- a playback device that reproduces an image from these storage media.
- FIG. 28 illustrates an example of a schematic configuration of a television apparatus to which the above-described embodiment is applied.
- the television apparatus 900 includes an antenna 901, a tuner 902, a demultiplexer 903, a decoder 904, a video signal processing unit 905, a display unit 906, an audio signal processing unit 907, a speaker 908, an external interface 909, a control unit 910, a user interface 911, And a bus 912.
- Tuner 902 extracts a signal of a desired channel from a broadcast signal received via antenna 901, and demodulates the extracted signal. Then, the tuner 902 outputs the encoded bit stream obtained by the demodulation to the demultiplexer 903. In other words, the tuner 902 serves as a transmission unit in the television apparatus 900 that receives an encoded stream in which an image is encoded.
- the demultiplexer 903 separates the video stream and audio stream of the viewing target program from the encoded bit stream, and outputs each separated stream to the decoder 904. In addition, the demultiplexer 903 extracts auxiliary data such as EPG (Electronic Program Guide) from the encoded bit stream, and supplies the extracted data to the control unit 910. Note that the demultiplexer 903 may perform descrambling when the encoded bit stream is scrambled.
- EPG Electronic Program Guide
- the decoder 904 decodes the video stream and audio stream input from the demultiplexer 903. Then, the decoder 904 outputs the video data generated by the decoding process to the video signal processing unit 905. In addition, the decoder 904 outputs audio data generated by the decoding process to the audio signal processing unit 907.
- the video signal processing unit 905 reproduces the video data input from the decoder 904 and causes the display unit 906 to display the video.
- the video signal processing unit 905 may cause the display unit 906 to display an application screen supplied via a network.
- the video signal processing unit 905 may perform additional processing such as noise removal on the video data according to the setting.
- the video signal processing unit 905 may generate a GUI (Graphical User Interface) image such as a menu, a button, or a cursor, and superimpose the generated image on the output image.
- GUI Graphic User Interface
- the display unit 906 is driven by a drive signal supplied from the video signal processing unit 905, and displays a video or an image on a video screen of a display device (for example, a liquid crystal display, a plasma display, or an OLED).
- a display device for example, a liquid crystal display, a plasma display, or an OLED.
- the audio signal processing unit 907 performs reproduction processing such as D / A conversion and amplification on the audio data input from the decoder 904, and outputs audio from the speaker 908.
- the audio signal processing unit 907 may perform additional processing such as noise removal on the audio data.
- the external interface 909 is an interface for connecting the television apparatus 900 to an external device or a network.
- a video stream or an audio stream received via the external interface 909 may be decoded by the decoder 904. That is, the external interface 909 also has a role as a transmission unit in the television apparatus 900 that receives an encoded stream in which an image is encoded.
- the control unit 910 has a processor such as a CPU (Central Processing Unit) and a memory such as a RAM (Random Access Memory) and a ROM (Read Only Memory).
- the memory stores a program executed by the CPU, program data, EPG data, data acquired via a network, and the like.
- the program stored in the memory is read and executed by the CPU when the television device 900 is activated, for example.
- the CPU controls the operation of the television device 900 according to an operation signal input from the user interface 911, for example, by executing the program.
- the user interface 911 is connected to the control unit 910.
- the user interface 911 includes, for example, buttons and switches for the user to operate the television device 900, a remote control signal receiving unit, and the like.
- the user interface 911 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 910.
- the bus 912 connects the tuner 902, the demultiplexer 903, the decoder 904, the video signal processing unit 905, the audio signal processing unit 907, the external interface 909, and the control unit 910 to each other.
- the decoder 904 has the function of the image decoding apparatus 60 according to the above-described embodiment. Thereby, for the multi-codec scalable decoding of images in the television apparatus 900, an improved mechanism for setting blocks in the enhancement layer can be adopted, and the encoding efficiency can be increased.
- FIG. 29 illustrates an example of a schematic configuration of a mobile phone to which the above-described embodiment is applied.
- a mobile phone 920 includes an antenna 921, a communication unit 922, an audio codec 923, a speaker 924, a microphone 925, a camera unit 926, an image processing unit 927, a demultiplexing unit 928, a recording / reproducing unit 929, a display unit 930, a control unit 931, an operation A portion 932 and a bus 933.
- the antenna 921 is connected to the communication unit 922.
- the speaker 924 and the microphone 925 are connected to the audio codec 923.
- the operation unit 932 is connected to the control unit 931.
- the bus 933 connects the communication unit 922, the audio codec 923, the camera unit 926, the image processing unit 927, the demultiplexing unit 928, the recording / reproducing unit 929, the display unit 930, and the control unit 931 to each other.
- the mobile phone 920 has various operation modes including a voice call mode, a data communication mode, a shooting mode, and a videophone mode, and is used for sending and receiving voice signals, sending and receiving e-mail or image data, taking images, and recording data. Perform the action.
- the analog voice signal generated by the microphone 925 is supplied to the voice codec 923.
- the audio codec 923 converts an analog audio signal into audio data, A / D converts the converted audio data, and compresses it. Then, the audio codec 923 outputs the compressed audio data to the communication unit 922.
- the communication unit 922 encodes and modulates the audio data and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921. In addition, the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal.
- the communication unit 922 demodulates and decodes the received signal to generate audio data, and outputs the generated audio data to the audio codec 923.
- the audio codec 923 expands the audio data and performs D / A conversion to generate an analog audio signal. Then, the audio codec 923 supplies the generated audio signal to the speaker 924 to output audio.
- the control unit 931 generates character data constituting the e-mail in response to an operation by the user via the operation unit 932.
- the control unit 931 causes the display unit 930 to display characters.
- the control unit 931 generates e-mail data in response to a transmission instruction from the user via the operation unit 932, and outputs the generated e-mail data to the communication unit 922.
- the communication unit 922 encodes and modulates email data and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921.
- the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal.
- the communication unit 922 demodulates and decodes the received signal to restore the email data, and outputs the restored email data to the control unit 931.
- the control unit 931 displays the content of the electronic mail on the display unit 930 and stores the electronic mail data in the storage medium of the recording / reproducing unit 929.
- the recording / reproducing unit 929 has an arbitrary readable / writable storage medium.
- the storage medium may be a built-in storage medium such as a RAM or a flash memory, or an externally mounted storage medium such as a hard disk, a magnetic disk, a magneto-optical disk, an optical disk, a USB memory, or a memory card. May be.
- the camera unit 926 images a subject to generate image data, and outputs the generated image data to the image processing unit 927.
- the image processing unit 927 encodes the image data input from the camera unit 926 and stores the encoded stream in the storage medium of the recording / playback unit 929.
- the demultiplexing unit 928 multiplexes the video stream encoded by the image processing unit 927 and the audio stream input from the audio codec 923, and the multiplexed stream is the communication unit 922. Output to.
- the communication unit 922 encodes and modulates the stream and generates a transmission signal. Then, the communication unit 922 transmits the generated transmission signal to a base station (not shown) via the antenna 921.
- the communication unit 922 amplifies a radio signal received via the antenna 921 and performs frequency conversion to acquire a received signal.
- These transmission signal and reception signal may include an encoded bit stream.
- the communication unit 922 demodulates and decodes the received signal to restore the stream, and outputs the restored stream to the demultiplexing unit 928.
- the demultiplexing unit 928 separates the video stream and the audio stream from the input stream, and outputs the video stream to the image processing unit 927 and the audio stream to the audio codec 923.
- the image processing unit 927 decodes the video stream and generates video data.
- the video data is supplied to the display unit 930, and a series of images is displayed on the display unit 930.
- the audio codec 923 decompresses the audio stream and performs D / A conversion to generate an analog audio signal. Then, the audio codec 923 supplies the generated audio signal to the speaker 924 to output audio.
- the image processing unit 927 has the functions of the image encoding device 10 and the image decoding device 60 according to the above-described embodiment. Accordingly, an improved mechanism for setting blocks in the enhancement layer can be adopted for multi-codec scalable encoding and decoding of images in the mobile phone 920, and encoding efficiency can be increased.
- FIG. 30 shows an example of a schematic configuration of a recording / reproducing apparatus to which the above-described embodiment is applied.
- the recording / reproducing device 940 encodes audio data and video data of a received broadcast program and records the encoded data on a recording medium.
- the recording / reproducing device 940 may encode audio data and video data acquired from another device and record them on a recording medium, for example.
- the recording / reproducing device 940 reproduces data recorded on the recording medium on a monitor and a speaker, for example, in accordance with a user instruction. At this time, the recording / reproducing device 940 decodes the audio data and the video data.
- the recording / reproducing device 940 includes a tuner 941, an external interface 942, an encoder 943, an HDD (Hard Disk Drive) 944, a disk drive 945, a selector 946, a decoder 947, an OSD (On-Screen Display) 948, a control unit 949, and a user interface. 950.
- Tuner 941 extracts a signal of a desired channel from a broadcast signal received via an antenna (not shown), and demodulates the extracted signal. Then, the tuner 941 outputs the encoded bit stream obtained by the demodulation to the selector 946. That is, the tuner 941 has a role as a transmission unit in the recording / reproducing apparatus 940.
- the external interface 942 is an interface for connecting the recording / reproducing apparatus 940 to an external device or a network.
- the external interface 942 may be, for example, an IEEE 1394 interface, a network interface, a USB interface, or a flash memory interface.
- video data and audio data received via the external interface 942 are input to the encoder 943. That is, the external interface 942 serves as a transmission unit in the recording / reproducing device 940.
- the encoder 943 encodes video data and audio data when the video data and audio data input from the external interface 942 are not encoded. Then, the encoder 943 outputs the encoded bit stream to the selector 946.
- the HDD 944 records an encoded bit stream in which content data such as video and audio is compressed, various programs, and other data on an internal hard disk. Also, the HDD 944 reads out these data from the hard disk when playing back video and audio.
- the disk drive 945 performs recording and reading of data to and from the mounted recording medium.
- the recording medium loaded in the disk drive 945 may be, for example, a DVD disk (DVD-Video, DVD-RAM, DVD-R, DVD-RW, DVD + R, DVD + RW, etc.) or a Blu-ray (registered trademark) disk. .
- the selector 946 selects an encoded bit stream input from the tuner 941 or the encoder 943 when recording video and audio, and outputs the selected encoded bit stream to the HDD 944 or the disk drive 945. In addition, the selector 946 outputs the encoded bit stream input from the HDD 944 or the disk drive 945 to the decoder 947 during video and audio reproduction.
- the decoder 947 decodes the encoded bit stream and generates video data and audio data. Then, the decoder 947 outputs the generated video data to the OSD 948. The decoder 904 outputs the generated audio data to an external speaker.
- the OSD 948 reproduces the video data input from the decoder 947 and displays the video. Further, the OSD 948 may superimpose a GUI image such as a menu, a button, or a cursor on the video to be displayed.
- a GUI image such as a menu, a button, or a cursor
- the control unit 949 includes a processor such as a CPU and memories such as a RAM and a ROM.
- the memory stores a program executed by the CPU, program data, and the like.
- the program stored in the memory is read and executed by the CPU when the recording / reproducing apparatus 940 is activated, for example.
- the CPU controls the operation of the recording / reproducing device 940 according to an operation signal input from the user interface 950, for example, by executing the program.
- the user interface 950 is connected to the control unit 949.
- the user interface 950 includes, for example, buttons and switches for the user to operate the recording / reproducing device 940, a remote control signal receiving unit, and the like.
- the user interface 950 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 949.
- the encoder 943 has the function of the image encoding apparatus 10 according to the above-described embodiment.
- the decoder 947 has the function of the image decoding device 60 according to the above-described embodiment.
- FIG. 31 illustrates an example of a schematic configuration of an imaging apparatus to which the above-described embodiment is applied.
- the imaging device 960 images a subject to generate an image, encodes the image data, and records it on a recording medium.
- the imaging device 960 includes an optical block 961, an imaging unit 962, a signal processing unit 963, an image processing unit 964, a display unit 965, an external interface 966, a memory 967, a media drive 968, an OSD 969, a control unit 970, a user interface 971, and a bus. 972.
- the optical block 961 is connected to the imaging unit 962.
- the imaging unit 962 is connected to the signal processing unit 963.
- the display unit 965 is connected to the image processing unit 964.
- the user interface 971 is connected to the control unit 970.
- the bus 972 connects the image processing unit 964, the external interface 966, the memory 967, the media drive 968, the OSD 969, and the control unit 970 to each other.
- the optical block 961 includes a focus lens and a diaphragm mechanism.
- the optical block 961 forms an optical image of the subject on the imaging surface of the imaging unit 962.
- the imaging unit 962 includes an image sensor such as a CCD or a CMOS, and converts an optical image formed on the imaging surface into an image signal as an electrical signal by photoelectric conversion. Then, the imaging unit 962 outputs the image signal to the signal processing unit 963.
- the signal processing unit 963 performs various camera signal processing such as knee correction, gamma correction, and color correction on the image signal input from the imaging unit 962.
- the signal processing unit 963 outputs the image data after the camera signal processing to the image processing unit 964.
- the image processing unit 964 encodes the image data input from the signal processing unit 963 and generates encoded data. Then, the image processing unit 964 outputs the generated encoded data to the external interface 966 or the media drive 968. The image processing unit 964 also decodes encoded data input from the external interface 966 or the media drive 968 to generate image data. Then, the image processing unit 964 outputs the generated image data to the display unit 965. In addition, the image processing unit 964 may display the image by outputting the image data input from the signal processing unit 963 to the display unit 965. Further, the image processing unit 964 may superimpose display data acquired from the OSD 969 on an image output to the display unit 965.
- the OSD 969 generates a GUI image such as a menu, a button, or a cursor, for example, and outputs the generated image to the image processing unit 964.
- the external interface 966 is configured as a USB input / output terminal, for example.
- the external interface 966 connects the imaging device 960 and a printer, for example, when printing an image.
- a drive is connected to the external interface 966 as necessary.
- a removable medium such as a magnetic disk or an optical disk is attached to the drive, and a program read from the removable medium can be installed in the imaging device 960.
- the external interface 966 may be configured as a network interface connected to a network such as a LAN or the Internet. That is, the external interface 966 has a role as a transmission unit in the imaging device 960.
- the recording medium mounted on the media drive 968 may be any readable / writable removable medium such as a magnetic disk, a magneto-optical disk, an optical disk, or a semiconductor memory. Further, a recording medium may be fixedly attached to the media drive 968, and a non-portable storage unit such as an internal hard disk drive or an SSD (Solid State Drive) may be configured.
- a non-portable storage unit such as an internal hard disk drive or an SSD (Solid State Drive) may be configured.
- the control unit 970 includes a processor such as a CPU and memories such as a RAM and a ROM.
- the memory stores a program executed by the CPU, program data, and the like.
- the program stored in the memory is read and executed by the CPU when the imaging device 960 is activated, for example.
- the CPU controls the operation of the imaging device 960 according to an operation signal input from the user interface 971, for example, by executing the program.
- the user interface 971 is connected to the control unit 970.
- the user interface 971 includes, for example, buttons and switches for the user to operate the imaging device 960.
- the user interface 971 detects an operation by the user via these components, generates an operation signal, and outputs the generated operation signal to the control unit 970.
- the image processing unit 964 has the functions of the image encoding device 10 and the image decoding device 60 according to the above-described embodiment. Accordingly, an improved mechanism for setting blocks in the enhancement layer can be adopted for multi-codec scalable encoding and decoding of images in the imaging device 960, and encoding efficiency can be increased.
- the data transmission system 1000 includes a stream storage device 1001 and a distribution server 1002.
- Distribution server 1002 is connected to several terminal devices via network 1003.
- Network 1003 may be a wired network, a wireless network, or a combination thereof.
- FIG. 32 shows a PC (Personal Computer) 1004, an AV device 1005, a tablet device 1006, and a mobile phone 1007 as examples of terminal devices.
- PC Personal Computer
- the stream storage device 1001 stores, for example, stream data 1011 including a multiplexed stream generated by the image encoding device 10.
- the multiplexed stream includes a base layer (BL) encoded stream and an enhancement layer (EL) encoded stream.
- the distribution server 1002 reads the stream data 1011 stored in the stream storage device 1001, and at least a part of the read stream data 1011 is transmitted via the network 1003 to the PC 1004, the AV device 1005, the tablet device 1006, and the mobile phone 1007. Deliver to.
- the distribution server 1002 selects a stream to be distributed based on some condition such as the capability of the terminal device or the communication environment. For example, the distribution server 1002 may avoid the occurrence of delay, overflow, or processor overload in the terminal device by not distributing an encoded stream having a high image quality that exceeds the image quality that can be handled by the terminal device. . The distribution server 1002 may avoid occupying the communication band of the network 1003 by not distributing an encoded stream having high image quality. On the other hand, the distribution server 1002 distributes all of the multiplexed streams to the terminal device when there is no risk to be avoided or when it is determined to be appropriate based on a contract with the user or some condition. Good.
- the distribution server 1002 reads the stream data 1011 from the stream storage device 1001. Then, the distribution server 1002 distributes the stream data 1011 as it is to the PC 1004 having high processing capability. Also, since the AV device 1005 has low processing capability, the distribution server 1002 generates stream data 1012 including only the base layer encoded stream extracted from the stream data 1011, and distributes the stream data 1012 to the AV device 1005. To do. Also, the distribution server 1002 distributes the stream data 1011 as it is to the tablet device 1006 that can communicate at a high communication rate. Further, since the cellular phone 1007 can communicate only at a low communication rate, the distribution server 1002 distributes the stream data 1012 including only the base layer encoded stream to the cellular phone 1007.
- the multiplexed stream By using the multiplexed stream in this way, the amount of traffic to be transmitted can be adjusted adaptively.
- the code amount of the stream data 1011 is reduced as compared with the case where each layer is individually encoded, even if the entire stream data 1011 is distributed, the load on the network 1003 is suppressed. Is done. Furthermore, memory resources of the stream storage device 1001 are also saved.
- the hardware performance of terminal devices varies from device to device.
- the communication capacity of the network 1003 also varies.
- the capacity available for data transmission can change from moment to moment due to the presence of other traffic. Therefore, the distribution server 1002 transmits terminal information regarding the hardware performance and application capability of the terminal device, the communication capacity of the network 1003, and the like through signaling with the distribution destination terminal device before starting the distribution of the stream data. And network information may be acquired. Then, the distribution server 1002 can select a stream to be distributed based on the acquired information.
- extraction of a layer to be decoded may be performed in the terminal device.
- the PC 1004 may display a base layer image extracted from the received multiplexed stream and decoded on the screen. Further, the PC 1004 may extract a base layer encoded stream from the received multiplexed stream to generate stream data 1012, store the generated stream data 1012 in a storage medium, or transfer the stream data 1012 to another device. .
- the configuration of the data transmission system 1000 shown in FIG. 32 is merely an example.
- the data transmission system 1000 may include any number of stream storage devices 1001, a distribution server 1002, a network 1003, and terminal devices.
- the data transmission system 1100 includes a broadcast station 1101 and a terminal device 1102.
- the broadcast station 1101 broadcasts a base layer encoded stream 1121 on the terrestrial channel 1111.
- the broadcast station 1101 transmits an enhancement layer encoded stream 1122 to the terminal device 1102 via the network 1112.
- the terminal device 1102 has a reception function for receiving a terrestrial broadcast broadcast by the broadcast station 1101, and receives a base layer encoded stream 1121 via the terrestrial channel 1111. Also, the terminal device 1102 has a communication function for communicating with the broadcast station 1101 and receives the enhancement layer encoded stream 1122 via the network 1112.
- the terminal device 1102 receives the base layer encoded stream 1121 in accordance with an instruction from the user, decodes the base layer image from the received encoded stream 1121, and displays the base layer image on the screen. Good. Further, the terminal device 1102 may store the decoded base layer image in a storage medium or transfer it to another device.
- the terminal device 1102 receives, for example, the enhancement layer encoded stream 1122 via the network 1112 in accordance with an instruction from the user, and receives the base layer encoded stream 1121 and the enhancement layer encoded stream 1122. Multiplexed streams may be generated by multiplexing. Also, the terminal apparatus 1102 may decode the enhancement layer image from the enhancement layer encoded stream 1122 and display the enhancement layer image on the screen. In addition, the terminal device 1102 may store the decoded enhancement layer image in a storage medium or transfer it to another device.
- the encoded stream of each layer included in the multiplexed stream can be transmitted via a different communication channel for each layer. Accordingly, it is possible to distribute the load applied to each channel and suppress the occurrence of communication delay or overflow.
- the communication channel used for transmission may be dynamically selected according to some condition. For example, a base layer encoded stream 1121 having a relatively large amount of data is transmitted via a communication channel having a wide bandwidth, and an enhancement layer encoded stream 1122 having a relatively small amount of data is transmitted via a communication channel having a small bandwidth. Can be transmitted. Further, the communication channel for transmitting the encoded stream 1122 of a specific layer may be switched according to the bandwidth of the communication channel. Thereby, the load applied to each channel can be more effectively suppressed.
- the configuration of the data transmission system 1100 shown in FIG. 33 is merely an example.
- the data transmission system 1100 may include any number of communication channels and terminal devices.
- the system configuration described here may be used for purposes other than broadcasting.
- the data transmission system 1200 includes an imaging device 1201 and a stream storage device 1202.
- the imaging device 1201 performs scalable coding on image data generated by imaging the subject 1211 and generates a multiplexed stream 1221.
- the multiplexed stream 1221 includes a base layer encoded stream and an enhancement layer encoded stream. Then, the imaging device 1201 supplies the multiplexed stream 1221 to the stream storage device 1202.
- the stream storage device 1202 stores the multiplexed stream 1221 supplied from the imaging device 1201 with different image quality for each mode. For example, the stream storage device 1202 extracts the base layer encoded stream 1222 from the multiplexed stream 1221 in the normal mode, and stores the extracted base layer encoded stream 1222. On the other hand, the stream storage device 1202 stores the multiplexed stream 1221 as it is in the high image quality mode. Thereby, the stream storage device 1202 can record a high-quality stream with a large amount of data only when it is desired to record a video with high quality. Therefore, it is possible to save memory resources while suppressing the influence of image quality degradation on the user.
- the imaging device 1201 is assumed to be a surveillance camera.
- the monitoring target for example, an intruder
- the normal mode is selected.
- the video is recorded with low image quality (that is, only the base layer coded stream 1222 is stored).
- the monitoring target for example, the subject 1211 as an intruder
- the high image quality mode is selected. In this case, since the captured image is likely to be important, priority is given to the high image quality, and the video is recorded with high image quality (that is, the multiplexed stream 1221 is stored).
- the mode is selected by the stream storage device 1202 based on the image analysis result, for example.
- the imaging device 1201 may select a mode. In the latter case, the imaging device 1201 may supply the base layer encoded stream 1222 to the stream storage device 1202 in the normal mode and supply the multiplexed stream 1221 to the stream storage device 1202 in the high image quality mode.
- the selection criteria for selecting the mode may be any standard.
- the mode may be switched according to the volume of sound acquired through a microphone or the waveform of sound. Further, the mode may be switched periodically. In addition, the mode may be switched according to an instruction from the user.
- the number of selectable modes may be any number as long as the number of layers to be layered does not exceed.
- the configuration of the data transmission system 1200 shown in FIG. 34 is merely an example.
- the data transmission system 1200 may include any number of imaging devices 1201. Further, the system configuration described here may be used in applications other than the surveillance camera.
- FIG. 35 is an explanatory diagram for describing a multi-view codec.
- a sequence of frames of three views captured at three viewpoints is shown. Each view is given a view ID (view_id). Any one of the plurality of views is designated as a base view. Views other than the base view are called non-base views.
- a view with a view ID “0” is a base view
- two views with a view ID “1” or “2” are non-base views.
- each view may correspond to a layer.
- the non-base view image is encoded and decoded with reference to the base view image (other non-base view images may also be referred to).
- FIG. 36 is a block diagram illustrating a schematic configuration of an image encoding device 10v that supports a multi-view codec.
- the image encoding device 10v includes a first layer encoding unit 1c, a second layer encoding unit 1d, a common memory 2, and a multiplexing unit 3.
- the function of the first encoding unit 1c is the same as that of the first encoding unit 1a described with reference to FIG. 8 except that it receives a base view image instead of a base layer image as an input.
- the first layer encoding unit 1c encodes the base view image and generates an encoded stream of the first layer.
- the function of the second encoding unit 1d is the same as the function of the second encoding unit 1b described with reference to FIG. 8 except that it receives a non-base view image instead of the enhancement layer image as an input.
- the second layer encoding unit 1d encodes the non-base view image and generates a second layer encoded stream.
- the common memory 2 stores information commonly used between layers.
- the multiplexing unit 3 multiplexes the encoded stream of the first layer generated by the first layer encoding unit 1c and the encoded stream of the second layer generated by the second layer encoding unit 1d. A multiplexed stream of layers is generated.
- FIG. 37 is a block diagram showing a schematic configuration of an image decoding device 60v that supports a multi-view codec.
- the image decoding device 60v includes a demultiplexing unit 5, a first layer decoding unit 6c, a second layer decoding unit 6d, and a common memory 7.
- the demultiplexer 5 demultiplexes the multi-layer multiplexed stream into the first layer encoded stream and the second layer encoded stream.
- the function of the first layer decoding unit 6c is the same as the function of the first decoding unit 6a described with reference to FIG. 9 except that it receives an encoded stream in which a base view image is encoded instead of a base layer image as an input. It is equivalent.
- the first layer decoding unit 6c decodes the base view image from the encoded stream of the first layer.
- the function of the second decoding unit 6d is the function of the second decoding unit 6b described with reference to FIG. 9 except that it receives an encoded stream in which a non-base view image is encoded instead of the enhancement layer image as an input. Is equivalent to The second layer decoding unit 6d decodes the non-base view image from the second layer encoded stream.
- the common memory 7 stores information commonly used between layers.
- encoding efficiency may be improved by setting blocks in a non-base view layer according to the technique according to the present disclosure.
- the technology according to the present disclosure may be applied to a streaming protocol.
- a streaming protocol For example, in MPEG-DASH (Dynamic Adaptive Streaming over HTTP), a plurality of encoded streams having different parameters such as resolution are prepared in advance in a streaming server. Then, the streaming server dynamically selects appropriate data to be streamed from a plurality of encoded streams in units of segments, and distributes the selected data.
- the technology according to the present disclosure may be employed.
- a multi-codec scalable in which a base layer is encoded by a macroblock-based image encoding scheme and an enhancement layer is encoded by a CU-based image encoding scheme that is recursively divided into blocks.
- a CU is set in the enhancement layer according to the block size set in the base layer. Therefore, higher encoding efficiency can be achieved as compared with a method of forming a Quad-Tree structure from scratch in the enhancement layer.
- the maximum size of the CU that is, the LCU size is determined using the block size in the base layer and the scalability ratio between layers.
- the block division into CUs in the LCU does not necessarily depend on the block size in the base layer. Therefore, the coding efficiency of the enhancement layer can be optimized by taking advantage of the flexibility of the Quad-Tree structure unique to HEVC, without being constrained by the lattice-like macroblock structure of the base layer.
- the LCU size is determined by using the macroblock size and the scalability ratio, it is not necessary to encode the block size information in the enhancement layer, so that the code amount can be reduced. Further, when the candidates for the LCU size are narrowed down based on the product of the macroblock size and the scalability ratio, the flexibility of setting the LCU size can be obtained while reducing the code amount.
- the method for transmitting such information is not limited to such an example.
- these pieces of information may be transmitted or recorded as separate data associated with the encoded bitstream without being multiplexed into the encoded bitstream.
- the term “associate” means that an image (which may be a part of an image such as a slice or a block) included in the bitstream and information corresponding to the image can be linked at the time of decoding. Means. That is, information may be transmitted on a transmission path different from that of the image (or bit stream).
- Information may be recorded on a recording medium (or another recording area of the same recording medium) different from the image (or bit stream). Furthermore, the information and the image (or bit stream) may be associated with each other in an arbitrary unit such as a plurality of frames, one frame, or a part of the frame.
- a first setting unit that sets a macroblock in a base layer decoded by a first coding scheme based on a macroblock having a fixed size
- a second encoding unit is set according to the block size set by the first setting unit in the enhancement layer decoded by the second encoding method based on the encoding unit that is recursively divided into blocks.
- An image processing apparatus comprising: (2) The image processing apparatus according to (1), wherein the second setting unit determines a size of a coding unit using a macroblock size and a scalability ratio between layers.
- the image processing apparatus according to (3) or (4), wherein the second setting unit determines a minimum size of an encoding unit according to a parameter acquired from an encoded stream.
- a first prediction unit that sets a first prediction block in the base layer and executes intra prediction or inter prediction for the first prediction block;
- a second prediction block corresponding to the first prediction block is set in the enhancement layer using the size of the first prediction block and the scalability ratio, and intra prediction is performed for the second prediction block.
- a second prediction unit that performs inter prediction;
- the image processing apparatus according to any one of (2) to (6), further including: (8)
- the second prediction unit determines the size of the second prediction block by multiplying the size of the first prediction block set by the first prediction unit by the scalability ratio.
- the second prediction unit is a parameter acquired from an encoded stream among a plurality of sizes narrowed down based on a product of the size of the first prediction block set by the first prediction unit and the scalability ratio.
- the image processing device according to (7), wherein the size selected according to is determined as the size of the second prediction block.
- the first prediction unit and the second prediction unit perform inter prediction, The second prediction unit is obtained from an encoded stream among a plurality of sizes narrowed down according to whether the first prediction unit uses division into sub-macroblocks when setting the first prediction block. Determining a size selected according to a parameter to be the size of the second prediction block; The image processing apparatus according to (7).
- a first transform unit that sets a first transform block in the base layer and performs inverse orthogonal transform on the first transform block; Using the size of the first transform block and the scalability ratio, a second transform block corresponding to the first transform block is set in the enhancement layer, and the second transform block is inversely orthogonal.
- the second conversion unit is a parameter acquired from an encoded stream among a plurality of sizes narrowed down based on a product of the size of the first conversion block set by the first conversion unit and the scalability ratio.
- An image processing method including: (15) A first setting unit that sets a macroblock in a base layer that is encoded by a first encoding scheme based on a macroblock having a fixed size; A coding unit is set according to the block size set by the first setting unit in the enhancement layer coded by the second coding method based on the coding unit that is recursively divided into blocks.
- An image processing apparatus comprising: (16) The image processing device according to (15), wherein the second setting unit determines a size of a coding unit using a macroblock size and a scalability ratio between layers. (17) The image processing device according to (16), wherein the second setting unit determines a maximum size of a coding unit by multiplying the macroblock size by the scalability ratio. (18) The image processing apparatus according to (17), wherein the second setting unit determines a minimum size of a coding unit by multiplying a sub macroblock size by the scalability ratio. (19) The image processing apparatus according to (17), wherein the second setting unit generates a parameter indicating a size selected as a minimum size of a coding unit.
- Image encoding device (image processing device) 12a Block setting unit (first setting unit) 12b Block setting unit (second setting unit) 14a Orthogonal transformation unit (first transformation unit) 14b Orthogonal transformation unit (second transformation unit) 30a Intra prediction unit (first prediction unit) 30b Intra prediction unit (second prediction unit) 40a Inter prediction unit (first prediction unit) 40b Inter prediction unit (second prediction unit) 60 Image decoding device (image processing device) 62a Block setting unit (first setting unit) 62b Block setting unit (second setting unit) 64a Inverse orthogonal transform unit (first transform unit) 64b Inverse orthogonal transform unit (second transform unit) 80a Intra prediction unit (first prediction unit) 80b Intra prediction unit (second prediction unit) 90a Inter prediction unit (first prediction unit) 90b Inter prediction unit (second prediction unit)
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Abstract
Description
-空間スケーラビリティ:空間解像度あるいは画像サイズが階層化される。
-時間スケーラビリティ:フレームレートが階層化される。
-SNR(Signal to Noise Ratio)スケーラビリティ:SN比が階層化される。
さらに、標準規格で未だ採用されていないものの、ビット深度スケーラビリティ及びクロマフォーマットスケーラビリティもまた議論されている。
1.概要
1-1.課題の説明
1-2.符号化単位に関するマッピング
1-3.変換単位に関するマッピング
1-4.予測単位に関するマッピング
1-5.エンコーダの基本的な構成例
1-6.デコーダの基本的な構成例
2.一実施形態に係る符号化部の構成例
2-1.全体的な構成
2-2.ブロック設定部の詳細な構成
2-3.直交変換部の詳細な構成
2-4.イントラ予測部の詳細な構成
2-5.インター予測部の詳細な構成
3.一実施形態に係る符号化時の処理の流れ
3-1.ブロック設定処理
3-2.直交変換処理
3-3.イントラ予測処理
3-4.インター予測処理
4.一実施形態に係る復号部の構成例
4-1.全体的な構成
4-2.ブロック設定部の詳細な構成
4-3.逆直交変換部の詳細な構成
4-4.イントラ予測部の詳細な構成
4-5.インター予測部の詳細な構成
5.一実施形態に係る復号時の処理の流れ
5-1.ブロック設定処理
5-2.逆直交変換処理
5-3.イントラ予測処理
5-4.インター予測処理
6.応用例
6-1.様々な製品への応用
6-2.スケーラブル符号化の様々な用途
6-3.その他
7.まとめ
[1-1.課題の説明]
スケーラブル符号化においては、一連の画像をそれぞれ含む複数のレイヤが符号化される。ベースレイヤ(base layer)は、最初に符号化される、最も粗い画像を表現するレイヤである。ベースレイヤの符号化ストリームは、他のレイヤの符号化ストリームを復号することなく、独立して復号され得る。ベースレイヤ以外のレイヤは、エンハンスメントレイヤ(enhancement layer)と呼ばれる、より精細な画像を表現するレイヤである。エンハンスメントレイヤの符号化ストリームは、ベースレイヤの符号化ストリームに含まれる情報を用いて符号化される。従って、エンハンスメントレイヤの画像を再現するためには、ベースレイヤ及びエンハンスメントレイヤの双方の符号化ストリームが復号されることになる。スケーラブル符号化において扱われるレイヤの数は、2つ以上のいかなる数であってもよい。3つ以上のレイヤが符号化される場合には、最下位のレイヤがベースレイヤ、残りの複数のレイヤがエンハンスメントレイヤである。より上位のエンハンスメントレイヤの符号化ストリームは、より下位のエンハンスメントレイヤ又はベースレイヤの符号化ストリームに含まれる情報を用いて符号化され及び復号され得る。本明細書では、依存関係を有する少なくとも2つのレイヤのうち、依存される側のレイヤを下位レイヤ(lower layer)、依存する側のレイヤを上位レイヤ(upper layer)という。
CUに関するマッピングの基本的な考え方として、本開示に係る技術では、ベースレイヤ内に設定されるマクロブロックのブロックサイズに応じて、HEVCで符号化されるエンハンスメントレイヤ内にCUを設定する。即ち、エンハンスメントレイヤでは、Quad-Tree構造が一から形成されるのではなく、ベースレイヤにおけるマクロブロックサイズを利用してQuad-Tree構造が形成される。
TUに関するマッピングの基本的な考え方は、CUに関するマッピングと類似する。本開示に係る技術では、ベースレイヤ内に設定される変換ブロックのサイズ、即ちDCT(Discrete Cosine Transform)サイズに応じて、エンハンスメントレイヤ内に設定されるTUのサイズが決定される。
PUに関するマッピングの基本的な考え方は、TUに関するマッピングと類似する。本開示に係る技術では、ベースレイヤ内に設定される予測ブロックのサイズに応じて、エンハンスメントレイヤ内に設定されるPUのサイズが決定される。
図8は、スケーラブル符号化をサポートする、一実施形態に係る画像符号化装置10の概略的な構成を示すブロック図である。図8を参照すると、画像符号化装置10は、第1符号化部1a、第2符号化部1b、共通メモリ2及び多重化部3を備える。
図9は、スケーラブル符号化をサポートする、一実施形態に係る画像復号装置60の概略的な構成を示すブロック図である。図9を参照すると、画像復号装置60は、逆多重化部5、第1復号部6a、第2復号部6b及び共通メモリ7を備える。
[2-1.全体的な構成]
図10は、図8に示した第1符号化部1a及び第2符号化部1bの構成の一例を示すブロック図である。図10を参照すると、第1符号化部1aは、並び替えバッファ11、ブロック設定部12a、減算部13、直交変換部14a、量子化部15、可逆符号化部16a、蓄積バッファ17、レート制御部18、逆量子化部21、逆直交変換部22a、加算部23、デブロックフィルタ24、フレームメモリ25、セレクタ26及び27、イントラ予測部30a、及びインター予測部40aを備える。第2符号化部1bは、ブロック設定部12a、直交変換部14a、可逆符号化部16a、逆直交変換部22a、イントラ予測部30a及びインター予測部40aの代わりに、ブロック設定部12b、直交変換部14b、可逆符号化部16b、逆直交変換部22b、イントラ予測部30b及びインター予測部40bを備える。
図11は、図10に示したブロック設定部12a及び12bの詳細な構成の一例を示すブロック図である。図11を参照すると、ブロック設定部12aは、設定制御部111a及びマクロブロック設定部112aを有する。ブロック設定部12bは、設定制御部111b及びCU設定部112bを有する。
ブロック設定部12aの設定制御部111aは、共通メモリ2により予め記憶される固定的なマクロブロックサイズを取得し、取得したサイズを有するマクロブロックの設定をマクロブロック設定部112aに指示する。
ブロック設定部12bの設定制御部111bは、共通メモリ2により記憶されるマクロブロックサイズ、及びベースレイヤとエンハンスメントレイヤとの間のスケーラビリティ比を取得する。スケーラビリティ比は、予め共通メモリ2により記憶されてもよく、又は2つのレイヤの解像度データから計算されてもよい。そして、設定制御部111bは、マクロブロックサイズとスケーラビリティ比とを用いて決定されるLCUサイズ及びSCUサイズの設定を、CU設定部112bに指示する。
図12は、図10に示した直交変換部14a及び14bの詳細な構成の一例を示すブロック図である。図12を参照すると、直交変換部14aは、変換制御部121a、4×4変換部122a、8×8変換部123a及びサイズ判定部126aを有する。直交変換部14bは、変換制御部121b、4×4変換部122b、8×8変換部123b、16×16変換部124b、32×32変換部125b及びサイズ判定部126bを有する。
直交変換部14aの変換制御部121aは、ベースレイヤの予測誤差データについて、マクロブロック内に4×4画素の変換ブロックを設定して、設定した変換ブロックごとに4×4変換部122aに直交変換を実行させる。また、変換制御部121aは、同様にマクロブロック内に8×8画素の変換ブロックを設定して、設定した変換ブロックごとに8×8変換部123aに直交変換を実行させる。そして、変換制御部121aは、最適なDCTサイズをサイズ判定部126aに判定させる。
直交変換部14bの変換制御部121bは、共通メモリ2により記憶されるDCTサイズ情報、及びスケーラビリティ比を取得する。そして、変換制御部121bは、DCTサイズとスケーラビリティ比とを用いて決定される1つ以上のサイズを有するTUをLCU内に設定する。
図13は、図10に示したイントラ予測部30a及び30bの詳細な構成の一例を示すブロック図である。図13を参照すると、イントラ予測部30aは、予測制御部131a、予測部132a及びモード判定部133aを有する。イントラ予測部30bは、予測制御部131b、予測部132b及びモード判定部133bを有する。
イントラ予測部30aの予測制御部131aは、ベースレイヤのイントラ予測処理を制御する。より具体的には、予測制御部131aは、ベースレイヤのマクロブロック内に様々なサイズを有する予測ブロックを設定して、様々な予測モードで予測部132aにイントラ予測を実行させる。そして、予測制御部131aは、最適な予測ブロックサイズ及び予測モードをモード判定部133aに判定させる。
イントラ予測部30bの予測制御部131bは、エンハンスメントレイヤのイントラ予測処理を制御する。より具体的には、予測制御部131bは、エンハンスメントレイヤのLCU内に1つ以上のPUを設定して、様々な予測モードで予測部132bにイントラ予測を実行させる。そして、予測制御部131bは、最適な予測モードをモード判定部133bに判定させる。
図14は、図10に示したインター予測部40a及び40bの詳細な構成の一例を示すブロック図である。図14を参照すると、インター予測部40aは、予測制御部141a、予測部142a及びモード判定部143aを有する。インター予測部40bは、予測制御部141b、予測部142b及びモード判定部143bを有する。
インター予測部40aの予測制御部141aは、ベースレイヤのインター予測処理を制御する。より具体的には、予測制御部141aは、ベースレイヤのマクロブロック内に様々なサイズを有する予測ブロックを設定する。また、予測制御部141aは、予測ブロックごとに参照画像を設定する。そして、予測制御部141aは、様々な予測モードで予測部142aにインター予測を実行させる。そして、予測制御部141aは、最適な予測ブロックサイズ及び予測モードをモード判定部143aに判定させる。
インター予測部40bの予測制御部141bは、エンハンスメントレイヤのインター予測処理を制御する。より具体的には、予測制御部141bは、エンハンスメントレイヤのLCU内に1つ以上のPUを設定して、予測部142bにインター予測を実行させる。そして、予測制御部141bは、最適な予測モードをモード判定部143bに判定させる。
次に、図15A~図18Bを用いて、一実施形態に係る符号化時の処理の流れについて説明する。なお、説明の簡明さのために、本開示に係る技術の要旨に直接的に関連しない処理の説明は省略される。
(1)第1の例
図15Aは、符号化時のエンハンスメントレイヤにおけるブロック設定処理の流れの第1の例を示すフローチャートである。図15Aに示したブロック設定処理は、図3Aを用いて説明したLCUサイズを設定するための第1の手法と、図4Aを用いて説明したSCUサイズを設定するための第1の手法との組合せに従った処理である。
図15Bは、符号化時のエンハンスメントレイヤにおけるブロック設定処理の流れの第2の例を示すフローチャートである。図15Bに示したブロック設定処理は、図3Bを用いて説明したLCUサイズを設定するための第2の手法と、図4Bを用いて説明したSCUサイズを設定するための第2の手法との組合せに従った処理である。
(1)第1の例
図16Aは、符号化時のエンハンスメントレイヤにおける直交変換処理の流れの第1の例を示すフローチャートである。図16Aに示した直交変換処理は、図5Aを用いて説明したTUサイズを設定するための第1の手法に従った処理である。
図16Bは、符号化時のエンハンスメントレイヤにおける直交変換処理の流れの第2の例を示すフローチャートである。図16Bに示した直交変換処理は、図5Bを用いて説明したTUサイズを設定するための第2の手法に従った処理である。
(1)第1の例
図17Aは、符号化時のエンハンスメントレイヤにおけるイントラ予測処理の流れの第1の例を示すフローチャートである。図17Aに示したイントラ予測処理は、図6Aを用いて説明したPUサイズを設定するための第1の手法に従った処理である。
図17Bは、符号化時のエンハンスメントレイヤにおけるイントラ予測処理の流れの第2の例を示すフローチャートである。図17Bに示したイントラ予測処理は、図6Bを用いて説明したPUサイズを設定するための第2の手法に従った処理である。
(1)第1の例
図18Aは、符号化時のエンハンスメントレイヤにおけるインター予測処理の流れの第1の例を示すフローチャートである。図18Aに示したインター予測処理は、図6Aを用いて説明したPUサイズを設定するための第1の手法をインター予測に応用した処理である。
図18Bは、符号化時のエンハンスメントレイヤにおけるインター予測処理の流れの第2の例を示すフローチャートである。図18Bに示したインター予測処理は、図7Bを用いて説明したPUサイズを設定するための第3の手法に従った処理である。
[4-1.全体的な構成]
図19は、図9に示した第1復号部6a及び第2復号部6bの構成の一例を示すブロック図である。図19を参照すると、第1復号部6aは、可逆復号部61a、ブロック設定部62a、逆量子化部63、逆直交変換部64a、加算部65、デブロックフィルタ66、並び替えバッファ67、D/A(Digital to Analogue)変換部68、フレームメモリ69、セレクタ70及び71、イントラ予測部80a並びにインター予測部90aを備える。第2復号部6bは、可逆復号部61a、ブロック設定部62a、逆直交変換部64a、イントラ予測部80a及びインター予測部90aの代わりに、可逆復号部61b、ブロック設定部62b、逆直交変換部64b、イントラ予測部80b及びインター予測部90bを備える。
図20は、図19に示したブロック設定部62a及び62bの詳細な構成の一例を示すブロック図である。図20を参照すると、ブロック設定部62aは、設定制御部161a及びマクロブロック設定部162aを有する。ブロック設定部62bは、設定制御部161b、サイズ設定部162b及びCU設定部163bを有する。
ブロック設定部62aの設定制御部161aは、共通メモリ7により予め記憶される固定的なマクロブロックサイズを取得し、取得したサイズを有するマクロブロックの設定をマクロブロック設定部162aに指示する。
ブロック設定部62bの設定制御部161bは、共通メモリ7により記憶されるマクロブロックサイズ、及びベースレイヤとエンハンスメントレイヤとの間のスケーラビリティ比を取得する。スケーラビリティ比は、可逆復号部61bにより復号されるパラメータにより直接的に示されてもよく、又は2つのレイヤの解像度データから計算されてもよい。そして、設定制御部161bは、マクロブロックサイズとスケーラビリティ比とを用いて決定されるLCUサイズ及びSCUサイズの設定を、サイズ設定部162bに指示する。
図21は、図19に示した逆直交変換部64a及び64bの詳細な構成の一例を示すブロック図である。図21を参照すると、逆直交変換部64aは、変換制御部171a、4×4変換部172a及び8×8変換部173aを有する。逆直交変換部64bは、変換制御部171b、4×4変換部172b、8×8変換部173b、16×16変換部174b及び32×32変換部175bを有する。
逆直交変換部64aの変換制御部171aは、可逆復号部61aにより復号されるDCTサイズ情報により示されるDCTサイズを有する変換ブロックを、マクロブロック内に設定する。そして、変換制御部171aは、4×4変換部172a及び8×8変換部173aのうち、設定したDCTサイズに対応する変換部に、逆量子化部63から入力されるベースレイヤの変換係数データについて逆直交変換を実行させる。また、変換制御部171aは、各変換ブロックのサイズを示すDCTサイズ情報を、共通メモリ7によりバッファリングさせる。
逆直交変換部64bの変換制御部171bは、共通メモリ7により記憶されるDCTサイズ情報、及びスケーラビリティ比を取得する。そして、変換制御部171bは、DCTサイズとスケーラビリティ比とを用いて決定されるサイズを有するTUをエンハンスメントレイヤの各CU内に設定する。
図22は、図19に示したイントラ予測部80a及び80bの詳細な構成の一例を示すブロック図である。図22を参照すると、イントラ予測部80aは、予測制御部181a、モード取得部182a及び予測部183aを有する。イントラ予測部80bは、予測制御部181b、モード取得部182b及び予測部183bを有する。
イントラ予測部80aの予測制御部181aは、ベースレイヤのイントラ予測処理を制御する。より具体的には、予測制御部181aは、可逆復号部61aにより復号される予測ブロックサイズ情報により示されるサイズを有する予測ブロックを、マクロブロック内に設定する。また、モード取得部182aは、可逆復号部61aにより復号される予測モード情報を取得する。そして、予測制御部181aは、予測モード情報により示される予測モードで、予測部183aにイントラ予測を実行させる。また、予測制御部181aは、各予測ブロックのサイズを示す予測ブロックサイズ情報を、共通メモリ7によりバッファリングさせる。
イントラ予測部80bの予測制御部181bは、エンハンスメントレイヤのイントラ予測処理を制御する。より具体的には、予測制御部181bは、エンハンスメントレイヤの各CU内にPUを設定する。予測制御部181bは、PUサイズを決定するために、スケーラビリティ比、及び共通メモリ7により記憶されるベースレイヤの予測ブロックサイズ情報を取得する。そして、予測制御部181bは、予測ブロックサイズとスケーラビリティ比とを用いて、設定すべきPUサイズを決定する。
図23は、図19に示したインター予測部90a及び90bの詳細な構成の一例を示すブロック図である。図23を参照すると、インター予測部90aは、予測制御部191a、情報取得部192a及び予測部193aを有する。インター予測部90bは、予測制御部191b、情報取得部192b及び予測部193bを有する。
インター予測部90aの予測制御部191aは、ベースレイヤのインター予測処理を制御する。より具体的には、予測制御部191aは、可逆復号部61aにより復号される予測ブロックサイズ情報により示されるサイズを有する予測ブロックを、マクロブロック内に設定する。また、情報取得部192aは、可逆復号部61aにより復号される予測モード情報及び動き情報を取得する。そして、予測制御部191aは、予測モード情報により示される予測モードで、予測部193aにインター予測を実行させる。また、予測制御部191aは、各予測ブロックのサイズを示す(サブマクロブロックタイプを含み得る)予測ブロックサイズ情報を、共通メモリ7によりバッファリングさせる。
インター予測部90bの予測制御部191bは、エンハンスメントレイヤのインター予測処理を制御する。より具体的には、予測制御部191bは、エンハンスメントレイヤの各CU内にPUを設定する。予測制御部191bは、PUサイズを決定するために、スケーラビリティ比、及び共通メモリ7により記憶されるベースレイヤの予測ブロックサイズ情報を取得する。そして、予測制御部191bは、予測ブロックサイズとスケーラビリティ比とを用いて、設定すべきPUサイズを決定する。
次に、図24A~図27Bを用いて、一実施形態に係る復号時の処理の流れについて説明する。なお、説明の簡明さのために、本開示に係る技術の要旨に直接的に関連しない処理の説明は省略される。
(1)第1の例
図24Aは、復号時のエンハンスメントレイヤにおけるブロック設定処理の流れの第1の例を示すフローチャートである。図24Aに示したブロック設定処理は、図3Aを用いて説明したLCUサイズを設定するための第1の手法と、図4Aを用いて説明したSCUサイズを設定するための第1の手法との組合せに従った処理である。
図24Bは、復号時のエンハンスメントレイヤにおけるブロック設定処理の流れの第2の例を示すフローチャートである。図24Bに示したブロック設定処理は、図3Bを用いて説明したLCUサイズを設定するための第2の手法と、図4Bを用いて説明したSCUサイズを設定するための第2の手法との組合せに従った処理である。
(1)第1の例
図25Aは、復号時のエンハンスメントレイヤにおける逆直交変換処理の流れの第1の例を示すフローチャートである。図25Aに示した逆直交変換処理は、図5Aを用いて説明したTUサイズを設定するための第1の手法に従った処理である。
図25Bは、復号時のエンハンスメントレイヤにおける逆直交変換処理の流れの第2の例を示すフローチャートである。図25Bに示した逆直交変換処理は、図5Bを用いて説明したTUサイズを設定するための第2の手法に従った処理である。
(1)第1の例
図26Aは、復号時のエンハンスメントレイヤにおけるイントラ予測処理の流れの第1の例を示すフローチャートである。図26Aに示したイントラ予測処理は、図6Aを用いて説明したPUサイズを設定するための第1の手法に従った処理である。
図26Bは、復号時のエンハンスメントレイヤにおけるイントラ予測処理の流れの第2の例を示すフローチャートである。図26Bに示したイントラ予測処理は、図6Bを用いて説明したPUサイズを設定するための第2の手法に従った処理である。
(1)第1の例
図27Aは、復号時のエンハンスメントレイヤにおけるインター予測処理の流れの第1の例を示すフローチャートである。図27Aに示したインター予測処理は、図6Aを用いて説明したPUサイズを設定するための第1の手法をインター予測に応用した処理である。
図27Bは、復号時のエンハンスメントレイヤにおけるインター予測処理の流れの第2の例を示すフローチャートである。図27Bに示したインター予測処理は、図7Bを用いて説明したPUサイズを設定するための第3の手法に従った処理である。
[6-1.様々な製品への応用]
上述した実施形態に係る画像符号化装置10及び画像復号装置60は、衛星放送、ケーブルTVなどの有線放送、インターネット上での配信、及びセルラー通信による端末への配信などにおける送信機若しくは受信機、光ディスク、磁気ディスク及びフラッシュメモリなどの媒体に画像を記録する記録装置、又は、これら記憶媒体から画像を再生する再生装置などの様々な電子機器に応用され得る。以下、4つの応用例について説明する。
図28は、上述した実施形態を適用したテレビジョン装置の概略的な構成の一例を示している。テレビジョン装置900は、アンテナ901、チューナ902、デマルチプレクサ903、デコーダ904、映像信号処理部905、表示部906、音声信号処理部907、スピーカ908、外部インタフェース909、制御部910、ユーザインタフェース911、及びバス912を備える。
図29は、上述した実施形態を適用した携帯電話機の概略的な構成の一例を示している。携帯電話機920は、アンテナ921、通信部922、音声コーデック923、スピーカ924、マイクロホン925、カメラ部926、画像処理部927、多重分離部928、記録再生部929、表示部930、制御部931、操作部932、及びバス933を備える。
図30は、上述した実施形態を適用した記録再生装置の概略的な構成の一例を示している。記録再生装置940は、例えば、受信した放送番組の音声データ及び映像データを符号化して記録媒体に記録する。また、記録再生装置940は、例えば、他の装置から取得される音声データ及び映像データを符号化して記録媒体に記録してもよい。また、記録再生装置940は、例えば、ユーザの指示に応じて、記録媒体に記録されているデータをモニタ及びスピーカ上で再生する。このとき、記録再生装置940は、音声データ及び映像データを復号する。
図31は、上述した実施形態を適用した撮像装置の概略的な構成の一例を示している。撮像装置960は、被写体を撮像して画像を生成し、画像データを符号化して記録媒体に記録する。
上述したスケーラブル符号化の利点は、様々な用途において享受され得る。以下、3つの用途の例について説明する。
第1の例において、スケーラブル符号化は、データの選択的な伝送のために利用される。図32を参照すると、データ伝送システム1000は、ストリーム記憶装置1001及び配信サーバ1002を含む。配信サーバ1002は、ネットワーク1003を介して、いくつかの端末装置と接続される。ネットワーク1003は、有線ネットワークであっても無線ネットワークであってもよく、又はそれらの組合せであってもよい。図32には、端末装置の例として、PC(Personal Computer)1004、AV機器1005、タブレット装置1006及び携帯電話機1007が示されている。
第2の例において、スケーラブル符号化は、複数の通信チャネルを介するデータの伝送のために利用される。図33を参照すると、データ伝送システム1100は、放送局1101及び端末装置1102を含む。放送局1101は、地上波チャネル1111上で、ベースレイヤの符号化ストリーム1121を放送する。また、放送局1101は、ネットワーク1112を介して、エンハンスメントレイヤの符号化ストリーム1122を端末装置1102へ送信する。
第3の例において、スケーラブル符号化は、映像の記憶のために利用される。図34を参照すると、データ伝送システム1200は、撮像装置1201及びストリーム記憶装置1202を含む。撮像装置1201は、被写体1211を撮像することにより生成される画像データをスケーラブル符号化し、多重化ストリーム1221を生成する。多重化ストリーム1221は、ベースレイヤの符号化ストリーム及びエンハンスメントレイヤの符号化ストリームを含む。そして、撮像装置1201は、多重化ストリーム1221をストリーム記憶装置1202へ供給する。
(1)マルチビューコーデックへの応用
マルチビューコーデックは、マルチレイヤコーデックの一種であり、いわゆる多視点映像を符号化し及び復号するための画像符号化方式である。図35は、マルチビューコーデックについて説明するための説明図である。図35を参照すると、3つの視点においてそれぞれ撮影される3つのビューのフレームのシーケンスが示されている。各ビューには、ビューID(view_id)が付与される。これら複数のビューのうちいずれか1つのビューが、ベースビュー(base view)に指定される。ベースビュー以外のビューは、ノンベースビューと呼ばれる。図35の例では、ビューIDが“0”であるビューがベースビューであり、ビューIDが“1”又は“2”である2つのビューがノンベースビューである。これらビューが階層的に符号化される場合、各ビューがレイヤに相当し得る。図中に矢印で示したように、ノンベースビューの画像は、ベースビューの画像を参照して符号化され及び復号される(他のノンベースビューの画像も参照されてよい)。
本開示に係る技術は、ストリーミングプロトコルに適用されてもよい。例えば、MPEG-DASH(Dynamic Adaptive Streaming over HTTP)では、解像度などのパラメータが互いに異なる複数の符号化ストリームがストリーミングサーバにおいて予め用意される。そして、ストリーミングサーバは、複数の符号化ストリームからストリーミングすべき適切なデータをセグメント単位で動的に選択し、選択したデータを配信する。このようなストリーミングプロトコルにおいて、本開示に係る技術が採用されてもよい。
ここまで、図1~図37を用いて、画像符号化装置10及び画像復号装置60の様々な実施形態について説明した。上述した実施形態によれば、マクロブロックベースの画像符号化方式でベースレイヤが符号化され、再帰的にブロック分割されるCUベースの画像符号化方式でエンハンスメントレイヤが符号化されるマルチコーデックのスケーラブル符号化において、ベースレイヤ内に設定されるブロックサイズに応じて、エンハンスメントレイヤ内にCUが設定される。従って、エンハンスメントレイヤにおいてQuad-Tree構造を一から形成する手法と比較して、高い符号化効率を達成することができる。
(1)
固定的なサイズを有するマクロブロックに基づく第1の符号化方式で復号されるベースレイヤ内にマクロブロックを設定する第1設定部と、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で復号されるエンハンスメントレイヤ内に、前記第1設定部により設定されるブロックサイズに応じて、符号化単位を設定する第2設定部と、
を備える画像処理装置。
(2)
前記第2設定部は、マクロブロックサイズとレイヤ間のスケーラビリティ比とを用いて、符号化単位のサイズを決定する、前記(1)に記載の画像処理装置。
(3)
前記第2設定部は、前記マクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最大サイズを決定する、前記(2)に記載の画像処理装置。
(4)
前記第2設定部は、前記マクロブロックサイズと前記スケーラビリティ比との積を基準として絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、符号化単位の最大サイズとして決定する、前記(2)に記載の画像処理装置。
(5)
前記第2設定部は、サブマクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最小サイズを決定する、前記(3)又は前記(4)に記載の画像処理装置。
(6)
前記第2設定部は、符号化ストリームから取得されるパラメータに従って、符号化単位の最小サイズを決定する、前記(3)又は前記(4)に記載の画像処理装置。
(7)
前記ベースレイヤ内に第1の予測ブロックを設定して、当該第1の予測ブロックについてイントラ予測又はインター予測を実行する第1予測部と、
前記第1の予測ブロックのサイズと前記スケーラビリティ比とを用いて、前記エンハンスメントレイヤ内に前記第1の予測ブロックに対応する第2の予測ブロックを設定して、当該第2の予測ブロックについてイントラ予測又はインター予測を実行する第2予測部と、
をさらに備える、前記(2)~(6)のいずれか1項に記載の画像処理装置。
(8)
前記第2予測部は、前記第1予測部により設定される前記第1の予測ブロックのサイズに前記スケーラビリティ比を乗じることにより、前記第2の予測ブロックのサイズを決定する、前記(7)に記載の画像処理装置。
(9)
前記第2予測部は、前記第1予測部により設定される前記第1の予測ブロックのサイズと前記スケーラビリティ比との積を基準として絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、前記第2の予測ブロックのサイズとして決定する、前記(7)に記載の画像処理装置。
(10)
前記第1予測部及び前記第2予測部は、インター予測を実行し、
前記第2予測部は、前記第1の予測ブロックを設定する際に前記第1予測部によりサブマクロブロックへの分割が使用されたかに応じて絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、前記第2の予測ブロックのサイズとして決定する、
前記(7)に記載の画像処理装置。
(11)
前記ベースレイヤ内に第1の変換ブロックを設定して、当該第1の変換ブロックについて逆直交変換を実行する第1変換部と、
前記第1の変換ブロックのサイズと前記スケーラビリティ比とを用いて、前記エンハンスメントレイヤ内に前記第1の変換ブロックに対応する第2の変換ブロックを設定して、当該第2の変換ブロックについて逆直交変換を実行する第2変換部と、
をさらに備える、前記(2)~(10)のいずれか1項に記載の画像処理装置。
(12)
前記第2変換部は、前記第1変換部により設定される前記第1の変換ブロックのサイズに前記スケーラビリティ比を乗じることにより、前記第2の変換ブロックのサイズを決定する、前記(11)に記載の画像処理装置。
(13)
前記第2変換部は、前記第1変換部により設定される前記第1の変換ブロックのサイズと前記スケーラビリティ比との積を基準として絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、前記第2の変換ブロックのサイズとして決定する、前記(11)に記載の画像処理装置。
(14)
固定的なサイズを有するマクロブロックに基づく第1の符号化方式で復号されるベースレイヤ内にマクロブロックを設定することと、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で復号されるエンハンスメントレイヤ内に、前記ベースレイヤ内に設定されたブロックサイズに応じて、符号化単位を設定することと、
を含む画像処理方法。
(15)
固定的なサイズを有するマクロブロックに基づく第1の符号化方式で符号化されるベースレイヤ内にマクロブロックを設定する第1設定部と、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で符号化されるエンハンスメントレイヤ内に、前記第1設定部により設定されるブロックサイズに応じて、符号化単位を設定する第2設定部と、
を備える画像処理装置。
(16)
前記第2設定部は、マクロブロックサイズとレイヤ間のスケーラビリティ比とを用いて、符号化単位のサイズを決定する、前記(15)に記載の画像処理装置。
(17)
前記第2設定部は、前記マクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最大サイズを決定する、前記(16)に記載の画像処理装置。
(18)
前記第2設定部は、サブマクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最小サイズを決定する、前記(17)に記載の画像処理装置。
(19)
前記第2設定部は、符号化単位の最小サイズとして選択されるサイズを示すパラメータを生成する、前記(17)に記載の画像処理装置。
(20)
固定的なサイズを有するマクロブロックに基づく第1の符号化方式で符号化されるベースレイヤ内にマクロブロックを設定することと、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で符号化されるエンハンスメントレイヤ内に、前記ベースレイヤ内に設定されるブロックサイズに応じて、符号化単位を設定することと、
を含む画像処理方法。
12a ブロック設定部(第1設定部)
12b ブロック設定部(第2設定部)
14a 直交変換部(第1変換部)
14b 直交変換部(第2変換部)
30a イントラ予測部(第1予測部)
30b イントラ予測部(第2予測部)
40a インター予測部(第1予測部)
40b インター予測部(第2予測部)
60 画像復号装置(画像処理装置)
62a ブロック設定部(第1設定部)
62b ブロック設定部(第2設定部)
64a 逆直交変換部(第1変換部)
64b 逆直交変換部(第2変換部)
80a イントラ予測部(第1予測部)
80b イントラ予測部(第2予測部)
90a インター予測部(第1予測部)
90b インター予測部(第2予測部)
Claims (20)
- 固定的なサイズを有するマクロブロックに基づく第1の符号化方式で復号されるベースレイヤ内にマクロブロックを設定する第1設定部と、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で復号されるエンハンスメントレイヤ内に、前記第1設定部により設定されるブロックサイズに応じて、符号化単位を設定する第2設定部と、
を備える画像処理装置。 - 前記第2設定部は、マクロブロックサイズとレイヤ間のスケーラビリティ比とを用いて、符号化単位のサイズを決定する、請求項1に記載の画像処理装置。
- 前記第2設定部は、前記マクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最大サイズを決定する、請求項2に記載の画像処理装置。
- 前記第2設定部は、前記マクロブロックサイズと前記スケーラビリティ比との積を基準として絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、符号化単位の最大サイズとして決定する、請求項2に記載の画像処理装置。
- 前記第2設定部は、サブマクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最小サイズを決定する、請求項3に記載の画像処理装置。
- 前記第2設定部は、符号化ストリームから取得されるパラメータに従って、符号化単位の最小サイズを決定する、請求項3に記載の画像処理装置。
- 前記ベースレイヤ内に第1の予測ブロックを設定して、当該第1の予測ブロックについてイントラ予測又はインター予測を実行する第1予測部と、
前記第1の予測ブロックのサイズと前記スケーラビリティ比とを用いて、前記エンハンスメントレイヤ内に前記第1の予測ブロックに対応する第2の予測ブロックを設定して、当該第2の予測ブロックについてイントラ予測又はインター予測を実行する第2予測部と、
をさらに備える、請求項2に記載の画像処理装置。 - 前記第2予測部は、前記第1予測部により設定される前記第1の予測ブロックのサイズに前記スケーラビリティ比を乗じることにより、前記第2の予測ブロックのサイズを決定する、請求項7に記載の画像処理装置。
- 前記第2予測部は、前記第1予測部により設定される前記第1の予測ブロックのサイズと前記スケーラビリティ比との積を基準として絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、前記第2の予測ブロックのサイズとして決定する、請求項7に記載の画像処理装置。
- 前記第1予測部及び前記第2予測部は、インター予測を実行し、
前記第2予測部は、前記第1の予測ブロックを設定する際に前記第1予測部によりサブマクロブロックへの分割が使用されたかに応じて絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、前記第2の予測ブロックのサイズとして決定する、
請求項7に記載の画像処理装置。 - 前記ベースレイヤ内に第1の変換ブロックを設定して、当該第1の変換ブロックについて逆直交変換を実行する第1変換部と、
前記第1の変換ブロックのサイズと前記スケーラビリティ比とを用いて、前記エンハンスメントレイヤ内に前記第1の変換ブロックに対応する第2の変換ブロックを設定して、当該第2の変換ブロックについて逆直交変換を実行する第2変換部と、
をさらに備える、請求項2に記載の画像処理装置。 - 前記第2変換部は、前記第1変換部により設定される前記第1の変換ブロックのサイズに前記スケーラビリティ比を乗じることにより、前記第2の変換ブロックのサイズを決定する、請求項11に記載の画像処理装置。
- 前記第2変換部は、前記第1変換部により設定される前記第1の変換ブロックのサイズと前記スケーラビリティ比との積を基準として絞り込まれる複数のサイズのうち、符号化ストリームから取得されるパラメータに従って選択されるサイズを、前記第2の変換ブロックのサイズとして決定する、請求項11に記載の画像処理装置。
- 固定的なサイズを有するマクロブロックに基づく第1の符号化方式で復号されるベースレイヤ内にマクロブロックを設定することと、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で復号されるエンハンスメントレイヤ内に、前記ベースレイヤ内に設定されたブロックサイズに応じて、符号化単位を設定することと、
を含む画像処理方法。 - 固定的なサイズを有するマクロブロックに基づく第1の符号化方式で符号化されるベースレイヤ内にマクロブロックを設定する第1設定部と、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で符号化されるエンハンスメントレイヤ内に、前記第1設定部により設定されるブロックサイズに応じて、符号化単位を設定する第2設定部と、
を備える画像処理装置。 - 前記第2設定部は、マクロブロックサイズとレイヤ間のスケーラビリティ比とを用いて、符号化単位のサイズを決定する、請求項15に記載の画像処理装置。
- 前記第2設定部は、前記マクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最大サイズを決定する、請求項16に記載の画像処理装置。
- 前記第2設定部は、サブマクロブロックサイズに前記スケーラビリティ比を乗じることにより、符号化単位の最小サイズを決定する、請求項17に記載の画像処理装置。
- 前記第2設定部は、符号化単位の最小サイズとして選択されるサイズを示すパラメータを生成する、請求項17に記載の画像処理装置。
- 固定的なサイズを有するマクロブロックに基づく第1の符号化方式で符号化されるベースレイヤ内にマクロブロックを設定することと、
再帰的にブロック分割される符号化単位に基づく第2の符号化方式で符号化されるエンハンスメントレイヤ内に、前記ベースレイヤ内に設定されるブロックサイズに応じて、符号化単位を設定することと、
を含む画像処理方法。
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CN109547791B (zh) * | 2018-10-26 | 2020-12-22 | 西安科锐盛创新科技有限公司 | 图像帧内预测方法及其装置 |
CN112839226B (zh) * | 2019-11-25 | 2024-02-23 | 深信服科技股份有限公司 | 一种图像编码、解码方法、相关装置及存储介质 |
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