WO2020048507A1 - 色度块预测方法以及设备 - Google Patents

色度块预测方法以及设备 Download PDF

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WO2020048507A1
WO2020048507A1 PCT/CN2019/104527 CN2019104527W WO2020048507A1 WO 2020048507 A1 WO2020048507 A1 WO 2020048507A1 CN 2019104527 W CN2019104527 W CN 2019104527W WO 2020048507 A1 WO2020048507 A1 WO 2020048507A1
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Prior art keywords
block
template
chroma
point
filter
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PCT/CN2019/104527
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English (en)
French (fr)
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马祥
杨海涛
陈建乐
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华为技术有限公司
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Priority to JP2021507937A priority Critical patent/JP7431803B2/ja
Priority to KR1020237021569A priority patent/KR20230098717A/ko
Priority to MX2021002486A priority patent/MX2021002486A/es
Priority to BR112021001991-0A priority patent/BR112021001991A2/pt
Priority to KR1020217003515A priority patent/KR102549670B1/ko
Priority to SG11202100113RA priority patent/SG11202100113RA/en
Priority to CN201980016632.8A priority patent/CN111801943B/zh
Priority to EP19858604.2A priority patent/EP3820152B1/en
Publication of WO2020048507A1 publication Critical patent/WO2020048507A1/zh
Priority to US17/166,364 priority patent/US11431991B2/en
Priority to US17/870,428 priority patent/US11962787B2/en

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • 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
    • H04N19/117—Filters, e.g. for pre-processing or post-processing
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
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    • 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
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    • 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
    • H04N19/13—Adaptive entropy coding, e.g. adaptive variable length coding [AVLC] or context adaptive binary arithmetic coding [CABAC]
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    • H04N19/157—Assigned coding mode, i.e. the coding mode being predefined or preselected to be further used for selection of another element or parameter
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
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    • H04N19/176—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 an image region, e.g. an object the region being a block, e.g. a macroblock
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    • H04N19/186—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 colour or a chrominance component
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    • H04N19/96—Tree coding, e.g. quad-tree coding

Definitions

  • the present invention relates to the field of video coding, and in particular, to a method and a device for predicting chroma blocks.
  • H.264 The currently widely used video coding standards H.264 / AVC (referred to as H.264) and H.265 / HEVC (referred to as H.265) both use image blocks as the basic unit for various types of encoding operations, such as based on Image block prediction, transformation, entropy coding, etc.
  • An image block refers to a two-dimensional sampling point array, that is, a WxH-sized array of pixel points (W may be equal to H or not equal to H), and the pixel values of the positions of each pixel are known.
  • the general video encoding process mainly includes intra prediction (IntertraPrediction), inter prediction (Inter prediction), transform (Transform), quantization (Quantization), entropy encoding (Entropy encoding), in-loop filtering (in-loop filtering), etc. Link. After the image is divided into image blocks, intra and inter predictions are performed, and after the residuals are obtained, transform quantization is performed, and finally entropy coding is performed and a code stream is output.
  • intra prediction uses the pixel values of pixels in the reconstructed area in the current image to predict the pixel values of pixels in the current block.
  • the pixels in the current block are used to derive the pixels in the current block.
  • Predictive value For example, in H.264 or H.265, the boundary pixels of neighboring blocks (near the side of the current block) are generally used as reference pixels of the current block, and based on these reference pixels, the current block is derived in a certain method.
  • the predicted value of the pixel is, for example, a non-directional mode of a DC (or average) mode and a planar mode, or a directional mode defined in H.265.
  • the residual information is obtained by subtracting the corresponding prediction information from the pixel values of the pixels in the current coding block, and then the discrete information is used to perform residual cosine transform (DCT) and other methods. Transform, and then use quantized entropy coding to get the code stream. After the prediction signal is added with the reconstructed residual signal, further filtering operations are required to obtain a reconstructed signal and use it as a reference signal for subsequent encoding.
  • DCT residual cosine transform
  • Decoding is equivalent to the reverse process of encoding.
  • the entropy decoding inverse quantization and inverse transformation is used to obtain residual information, and the decoded bitstream determines whether the current block uses intra or inter prediction. If it is intra coding, the pixel information of the pixels in the reconstructed area around the current image is used to construct prediction information according to the used intra prediction method. Reconstruction information can be obtained by using prediction information plus residual information through a filtering operation.
  • the existing video is generally a color video.
  • the image in the color video also contains a chrominance component. Therefore, in addition to encoding the luminance component, it is also necessary to encode the chrominance component. How to improve the coding efficiency of chrominance components in intra prediction is still a technical challenge.
  • Embodiments of the present invention provide a chroma block prediction method and device, which can improve the coding efficiency of a chroma component (chroma block) in intra prediction.
  • an embodiment of the present invention provides a chroma block prediction method, which is described from the perspective of an encoding end. This method can be applied to the intra prediction of a current chroma block, and the intra prediction mode adopted is a linear model mode.
  • the method may include: determining a filter type according to a sampling point position type of the current chroma block, the filter type being determined by a sampling point position type of the current chroma block, each Each of the current chroma block sampling point position types has a corresponding filter type; setting a first indication information, the first indication information is used to indicate the filter type; the first indication information is coded into a code stream In order to facilitate subsequent sending to the decoding end.
  • the encoder may determine the brightness downsampling filter used by the current luma block according to the type of the sampling position of the current chroma point, and specify the type of the downsampling filter to the decoder through the instruction information. .
  • the encoder may determine the brightness downsampling filter used by the current luma block according to the type of the sampling position of the current chroma point, and specify the type of the downsampling filter to the decoder through the instruction information.
  • sampling point position types may be designed, and the six sampling point position types include: type0, type1, type2, type3, type4, and type5. Then, corresponding to the six types of sampling point positions, there are six types of brightness downsampling filters: filter 0, filter 1, filter 2, filter 3, filter 4, and filter 5. That is, the sampling point position type of the current chroma block may be one of the six sampling point position types.
  • two sampling point position types can also be designed, that is, the two sampling point position types only include: type0, type2.
  • the two sampling point position types there are two types of brightness downsampling filters: filter 0 and filter 2. That is, the sampling point position type of the current chroma block may be one of two sampling point position types.
  • a sequence parameter set (SPS) parameter may be added, and the value of this SPS parameter will be used to indicate the brightness in the LM mode when the current video sequence is encoded or decoded
  • SPS sequence parameter set
  • this parameter can be set based on the sampling position of the chroma points of the current sequence.
  • the first indication information may be set according to the type of the filter, and the first indication information includes the value of the SPS parameter, which is used to indicate the luminance downsampling filter used in the prediction of the chroma block during encoding or decoding. Types of.
  • multiple intra prediction modes may also be preset.
  • the multiple intra prediction modes include the LM mode, and the encoding end traverses the multiple Kinds of intra prediction modes, and determine that the optimal intra prediction mode in the prediction of the current chroma block is the LM mode.
  • the encoding end may further set second instruction information, where the second instruction information is used to instruct the LM. Mode, and the second instruction information is coded into the code stream, so that the decoding end also uses the LM mode for intra prediction and improves coding efficiency.
  • the encoding end may further determine a filter corresponding to the filter type according to the first indication information; according to the filter type, A filter that down-samples the first luma block to obtain a second luma block, where the first luma block is a luma block corresponding to the current chroma block; obtains a template chroma point and a template luma point, and the template color
  • the degree point includes a plurality of adjacent chromaticity pixel points of the current chrominance block, and the template brightness point is obtained by downsampling the plurality of adjacent brightness pixel points of the first luminance block; according to the template chromaticity Point and the template luminance point to obtain a linear model coefficient; and obtain a predicted value of the current chrominance block according to the second luminance block and the linear model coefficient.
  • an embodiment of the present invention provides a chroma block prediction method.
  • the method can be applied to intra prediction of a current chroma block, and an intra prediction mode adopted is an LM mode.
  • the method includes: parsing a bitstream to obtain first indication information, where the first indication information is used to indicate a filter type; and performing a downsampling operation on a first luminance block according to a filter corresponding to the filter type to obtain a second A luma block, the first luma block is a luma block corresponding to the current chroma block, and the positions of the luma pixels of the second luma block are consistent with the positions of the chroma pixels of the current chroma block; obtaining a template chroma point And a template luminance point, the template chrominance point includes a plurality of chrominance pixel points adjacent to the current chrominance block, and the template luminance point is performed on the plurality of luminance pixel points adjacent to the first luminance
  • the decoder can determine the filter used in the down-sampling of the luma block corresponding to the current chroma block through the indication information in the code stream. . Therefore, a filter matching the sampling position of the chroma points can be obtained, which is beneficial to take into account that different video sequences may have different positions of the chroma sampling points in reality, and improve coding efficiency and coding accuracy.
  • the adjacent upper and left sides used to calculate the coefficients of the linear model may be referred to as a template.
  • a template represents a set of luma points or chroma points used to calculate linear model coefficients.
  • the set of luma samples used to calculate linear model coefficients can also be referred to as template luma points.
  • Multiple luminance pixel points adjacent to the luma block are obtained by performing a downsampling operation (because there may not be a luminance sample value at a position matching the template chroma point in the luminance image).
  • the set of chroma points used to calculate the coefficients of the linear model may also be referred to as a template chroma point, and the template chroma point includes a plurality of reconstructed chroma pixel points adjacent to the current chroma block.
  • the template chroma point specifically includes chroma pixel points adjacent to the current chroma block in one line or multiple lines above, and the current chroma block is adjacent to Chroma pixels in the left or more columns.
  • the template luminance point and the template chrominance point correspond one-to-one, and the values of the sampling points constitute a value pair.
  • the template chroma points are a row of chroma pixel points adjacent to the upper row of the current chroma block, and a column of chroma pixels.
  • the template luminance point includes a row of luminance pixel points that match the position of each chrominance point in the template chrominance point, and a left column of luminance pixels.
  • the template chroma points are two rows of chroma pixel points adjacent to the upper side of the current chroma block, and two columns of chroma pixel points on the left side.
  • the template luminance point includes two rows of luminance pixel points and two columns of luminance pixel points that match the position of each chrominance point in the template chrominance point.
  • the template chromaticity point may also include only the chromaticity pixel points adjacent to the left column or multiple columns to the left of the current chrominance block.
  • the template luminance points and the template chrominance points correspond one-to-one, and only include one or more columns of luminance pixel points that match the position.
  • the template chroma points may also include only chroma pixel points adjacent to the current chroma block in one row or multiple rows.
  • the template luminance point and the template chrominance point correspond one-to-one, and only include one or more rows of luminance pixel points that match the position.
  • a filter corresponding to the filter type may be used to filter the adjacent adjacent first luminance blocks.
  • a plurality of brightness pixel points are subjected to a downsampling operation to obtain the template brightness point.
  • the decoder uses the same filter in the down-sampling process of deriving the brightness points of the template and the down-sampling process of the current block, thereby improving processing efficiency.
  • the brightness down-sampling filter used is filter 0. You can use this filter 0 to adjust the first brightness.
  • a plurality of brightness pixel points adjacent to the block are subjected to a downsampling operation to obtain the value of each brightness pixel point in the template brightness point.
  • the second indication information may also be obtained by parsing the bitstream, and the second indication information is used to instruct the decoding end to decode the current chroma block
  • the adopted intra prediction mode is the LM mode, so that the decoding end determines that the intra prediction of the current image of the video sequence adopts the LM mode.
  • the method is used to decode a current image block in a video sequence, where the current image block includes the first luma block and the current chroma block, and the video sequence
  • the encoding end and the decoding end may design the same filter type.
  • the encoding end is designed with 6 filter types (corresponding to the position of 6 chroma sampling points), the decoding end is also designed with 6 filter types, and the downsampling algorithms of the 6 filter types at the decoding end are respectively
  • the encoding ends are consistent.
  • the encoding end is designed with 2 types of filters (corresponding to the positions of 2 chroma sampling points), the decoding end is also designed with 2 types of filters, and the 2 types of filtering at the decoding end are down-sampled respectively. Consistent with the encoding end
  • the first indication information includes a value of the SPS parameter, which is used to indicate a type of a luminance down-sampling filter used in prediction of a chroma block when encoding or decoding.
  • obtaining a linear model coefficient according to the template chromaticity point and the template brightness point includes: using a least square based on the template chromaticity point and the template brightness point. Multiplication method to obtain linear model coefficients ⁇ and ⁇ .
  • obtaining a linear model coefficient according to the template chromaticity point and the template brightness point includes: using extreme values according to the template chromaticity point and the template brightness point Method to find the linear model coefficients ⁇ and ⁇ .
  • the method can be applied to the intra prediction of the current chroma block, and can be described from the perspective of the decoding end.
  • the intra prediction mode used is, for example, the LM mode.
  • the method includes: determining a filter type according to a sampling point position of a current chroma block; and performing a downsampling operation on a first luma block according to a filter corresponding to the filter type to obtain a second luma block, the first luma block Is the luma block corresponding to the current chroma block; obtaining a template chroma point and a template luma point, the template chroma point includes a plurality of chroma pixel points adjacent to the current chroma block, and the template luma point is A plurality of adjacent luminance pixel points of the first luminance block are obtained by performing a downsampling operation; obtaining a linear model coefficient according to the template chrominance point and the template luminance point; according to the second luminance
  • the encoder can determine the luminance downsampling filter used by the current luminance block according to the sampling point position of the current chrominance block, so that a filter matching the sampling position of the chrominance point can be obtained. It is beneficial to take into account the fact that different video sequences may have different chroma sampling point positions, and improve coding efficiency and coding accuracy.
  • the method before determining the filter type according to the sampling point position of the current chroma block, includes: parsing a bitstream to obtain first indication information, where the first indication information is used to indicate the The sampling point position of the current chroma block.
  • a position of a sampling point of the current chroma block may be associated with the filter type.
  • the encoder can determine the sampling point position of the current chroma point according to the first instruction information, so that a filter matching the sampling point position of the chroma point can be obtained. Since both the encoding end and the decoding end can obtain a filter matching the sampling position of the chroma point, the encoding accuracy and encoding efficiency of the encoding end are improved.
  • the sampling point position of the current chroma block may be determined, for example, by a sampling point position type of the current chroma block.
  • the sampling point position type of the current chroma block may be associated with the filter type.
  • the sampling point position type of the current chroma block is at least one of the following sampling point position types: a sampling point position type type0, and a sampling point position type type2.
  • sampling point position type of the current chroma block is at least one of the following sampling point position types: sampling point position type type0, sampling point position type type1, sampling point position type type2, and sampling point Position type type3, sampling point position type type4, sampling point position type type5.
  • the parsing the bitstream to obtain the first indication information includes: parsing a sequence parameter set (SPS) parameter in the bitstream to obtain the first indication information.
  • the encoder can indicate the type of the sampling point position of the current chroma block to the decoder through a certain SPS parameter, which is equivalent to specifying the type of the downsampling filter to the decoder, thereby ensuring the encoder and the decoder. Filters that match the sampling position of the chrominance points can be obtained.
  • an embodiment of the present invention provides a device for encoding video data, where the device includes a memory and a coupled encoder, where the memory is used to store video data in a bitstream format; the encoder is used to The filter type is determined according to the sampling point position type of the current chroma block; first instruction information is set, and the first instruction information is used to indicate the filter type; and the first instruction information is coded into a code stream.
  • the device may be used to implement the method described in the first aspect.
  • an embodiment of the present invention provides a device for decoding video data, where the device includes a memory and a coupled decoder, where the memory is used to store video data in a bitstream format; the decoder is used to: Analyze the bitstream to obtain first indication information, where the first indication information is used to indicate a filter type; according to a filter corresponding to the filter type, perform a downsampling operation on the first luma block to obtain a second luma block.
  • the first luma block is a luma block corresponding to the current chroma block; obtaining a template chroma point and a template luma point, the template chroma point including a plurality of chroma pixel points adjacent to the current chroma block, the
  • the template brightness point is obtained by performing a downsampling operation on a plurality of brightness pixel points adjacent to the first brightness block; obtaining a linear model coefficient according to the template chromaticity point and the template brightness point; according to the second brightness Block and the linear model coefficient to obtain a predicted value of the current chroma block.
  • the device may be used to implement the method described in the second aspect.
  • an embodiment of the present invention provides a device for decoding video data, where the device includes a memory and a coupled decoder, where the memory is used to store video data in a bitstream format; the decoder is used to: The filter type is determined according to the sampling point position type of the current chrominance block; according to the filter corresponding to the filter type, the first luminance block is down-sampled to obtain a second luminance block, where the first luminance block is the current A luma block corresponding to the chroma block; obtaining a template chroma point and a template luma point, the template chroma point includes a plurality of chroma pixel points adjacent to the current chroma block, and the template luma point is A plurality of adjacent luminance pixel points of the first luminance block are obtained by performing a downsampling operation; a linear model coefficient is obtained according to the template chrominance point and the template luminance point; according to the second luminance block and the
  • an embodiment of the present invention provides an encoding device, including: a non-volatile memory and a processor coupled to each other, where the processor calls program code stored in the memory to execute the description in the first aspect Methods.
  • an embodiment of the present invention provides a decoding device, including: a non-volatile memory and a processor coupled to each other, the processor calling program code stored in the memory to execute the description in the second aspect Methods.
  • an embodiment of the present invention provides a decoding device, including: a non-volatile memory and a processor coupled to each other, the processor invoking program code stored in the memory to execute the description in the third aspect Methods.
  • an embodiment of the present invention provides a system, where the system includes the device according to the fourth aspect and the device according to the fifth aspect, or the system includes the device according to the fourth aspect And the device according to the sixth aspect.
  • an embodiment of the present invention provides another system, where the system includes the encoding device according to the seventh aspect and the decoding device according to the eighth aspect, or the system includes the device according to the seventh aspect.
  • an embodiment of the present invention provides a non-volatile computer-readable storage medium; the computer-readable storage medium is configured to store implementation code of the method described in the first aspect.
  • the program code is executed by a computing device, the computing device is used in the method according to the first aspect.
  • an embodiment of the present invention provides still another non-volatile computer-readable storage medium; the computer-readable storage medium is configured to store code for implementing the method described in the second aspect or the third aspect.
  • the program code is executed by a computing device, the user equipment is used in the method according to the second aspect or the third aspect.
  • an embodiment of the present invention provides a computer program product.
  • the computer program product includes program instructions.
  • the controller executes the method described in the first aspect.
  • the computer program product may be a software installation package.
  • the computer program product may be downloaded and executed on a controller to Implement the method described in the first aspect.
  • an embodiment of the present invention provides another computer program product.
  • the computer program product includes program instructions.
  • the controller executes the method provided by any one of the foregoing second aspect or third possible design.
  • the computer program product may be a software installation package. If the method provided by any of the foregoing second or third possible design is needed, the computer program product may be downloaded and executed on the controller.
  • the encoder can determine the luminance downsampling filter used by the current luminance block according to the sampling point position of the current chrominance block, and use the indication information (such as newly added SPS parameters Value) to specify the type of downsampling filter to the decoder.
  • both the encoding end and the decoding end can obtain a filter that matches the sampling position of the chroma point, which is conducive to taking into account the fact that different video sequences may have different positions of the chroma sampling point, and ensuring that the position of the down-sampled luminance point and the The chroma sampling point positions are consistent, thereby improving the coding accuracy and coding efficiency of the coding end.
  • FIG. 1A is a block diagram showing an example of a video decoding system for implementing an embodiment of the present invention
  • FIG. 1B shows a block diagram of an example of a video decoding system including any one or both of the encoder 20 of FIG. 2 and the decoder 30 of FIG. 3;
  • FIG. 2 is a block diagram showing an example structure of an encoder for implementing an embodiment of the present invention
  • FIG. 3 is a block diagram showing a structure of a decoder example for implementing an embodiment of the present invention
  • FIG. 4 shows a block diagram of an example of an encoding device or a decoding device
  • FIG. 5 is a block diagram showing another example of an encoding device or a decoding device
  • FIG. 6 is a schematic diagram showing several formats of a YUV image
  • FIG. 7 is a schematic diagram showing a relationship between a position of a chroma sampling point and a position of a luminance sampling point
  • FIG. 8 illustrates an embodiment of a luma block, a down-sampled luma block, and a current chroma block
  • FIG. 9 illustrates an embodiment of a template luminance point and a template chrominance point
  • FIG. 10 shows still another embodiment of a template luminance point and a template chrominance point
  • FIG. 11 illustrates an exemplary diagram of the positional relationship between the positions of some chroma sampling points and the positions of luma sampling points
  • FIG. 12 shows a flowchart of a chroma block prediction method according to an embodiment of the present invention
  • FIG. 13 shows a flowchart of still another chroma block prediction method according to an embodiment of the present invention.
  • FIG. 14 is a schematic diagram showing a distribution of pixel value pairs in a luminance-chrominance coordinate system
  • 16 is a block diagram showing an example structure of a content supply system that implements a content distribution service
  • FIG. 17 is a block diagram showing the structure of an example of a terminal device.
  • Video coding generally refers to processing a sequence of pictures that form a video or a video sequence.
  • picture In the field of video coding, the terms “picture”, “frame” or “image” can be used as synonyms.
  • Video encoding as used herein means video encoding or video decoding.
  • Video encoding is performed on the source side and typically involves processing (e.g., by compressing) the original video picture to reduce the amount of data required to represent the video picture, thereby storing and / or transmitting more efficiently.
  • Video decoding is performed on the destination side and usually involves inverse processing relative to the encoder to reconstruct the video picture.
  • the video picture “encoding” involved in the embodiment should be understood as the “encoding” or “decoding” of the video sequence.
  • the combination of the encoding part and the decoding part is also called codec (encoding and decoding).
  • Each picture in multiple pictures of a video sequence is usually partitioned into a set of non-overlapping blocks, which is usually encoded at the block level.
  • the encoder side usually processes at the block (also called image block, or video block) level, that is, encodes the video.
  • the prediction block is generated by spatial (intra-picture) prediction and temporal (inter-picture) prediction.
  • the current block (currently processed or block to be processed) is subtracted from the prediction block to obtain the residual block, the residual block is transformed in the transform domain and the residual block is quantized to reduce the amount of data to be transmitted (compressed), and the decoder side will
  • the inverse processing part relative to the encoder is applied to the encoded or compressed block to reconstruct the current block for representation.
  • the encoder duplicates the decoder processing loop so that the encoder and decoder generate the same predictions (such as intra prediction and inter prediction) and / or reconstruction for processing, that is, encoding subsequent blocks.
  • the term "block” is part of a picture or frame.
  • the current block refers to the block currently being processed. For example, in encoding, it means the block that is currently being encoded; in decoding, it means the block that is currently being decoded. If the currently processed block is a chroma component block, it is called the current chroma block.
  • the luma block corresponding to the current chroma block may be referred to as the current luma block.
  • a reference block refers to a block that provides a reference signal for a current block, where the reference signal represents a pixel value or a sample value or a sample signal within an image block.
  • a prediction block is a block that provides a prediction signal for a current block, where the prediction signal represents a pixel value or a sampling value or a sampling signal within the prediction block. For example, after traversing multiple reference blocks, the best reference block is found. This best reference block will provide prediction for the current block. This block is called a prediction block.
  • a pixel point (or a pixel) may also be referred to as a sampling point, and accordingly, a pixel value may also be referred to as a value (or a sampling value) of the sampling point.
  • the current block may be referred to as a current luminance block (or a current luminance image block).
  • the current image block may be referred to as a current chroma block (or a current chroma image block).
  • FIG. 1A is a block diagram of a video decoding system 10 according to an example described in the embodiment of the present invention.
  • the term "video coder” generally refers to both video encoders and video decoders.
  • the terms "video coding” or “coding” may generally refer to video encoding or video decoding.
  • the video decoding system 10 may include a source device 12 and a destination device 14.
  • the source device 12 generates encoded video data. Therefore, the source device 12 may be referred to as a video encoding device.
  • the destination device 14 may decode the encoded video data generated by the source device 12, and thus, the destination device 14 may be referred to as a video decoding device.
  • Various implementations of the source device 12, the destination device 14, or both may include one or more processors and a memory coupled to the one or more processors.
  • the memory may include, but is not limited to, RAM, ROM, EEPROM, flash memory, or any other media that can be used to store the desired program code in the form of instructions or data structures accessible by a computer, as described herein.
  • the source device 12 and the destination device 14 may include various devices including desktop computers, mobile computing devices, notebook (e.g., laptop) computers, tablet computers, set-top boxes, telephone handsets, such as so-called "smart" phones, etc. Cameras, televisions, cameras, display devices, digital media players, video game consoles, on-board computers, or the like.
  • the source device 12 and the destination device 14 may be communicatively connected through a link 13, and the destination device 14 may receive encoded video data from the source device 12 via the link 13.
  • the link 13 may include one or more media or devices capable of moving the encoded video data from the source device 12 to the destination device 14.
  • the link 13 may include one or more communication media enabling the source device 12 to directly transmit the encoded video data to the destination device 14 in real time.
  • the source device 12 may modulate the encoded video data according to a communication standard, such as a wireless communication protocol, and may transmit the modulated video data to the destination device 14.
  • the one or more communication media may include wireless and / or wired communication media, such as a radio frequency (RF) spectrum or one or more physical transmission lines.
  • RF radio frequency
  • the one or more communication media may form part of a packet-based network, such as a local area network, a wide area network, or a global network (eg, the Internet).
  • the one or more communication media may include routers, switches, base stations, or other devices that facilitate communication from the source device 12 to the destination device 14.
  • the source device 12 includes an encoder 20.
  • the source device 12 may further include a picture source 16, a picture pre-processor 18, and a communication interface 22.
  • the encoder 20, the picture source 16, the picture preprocessor 18, and the communication interface 22 may be hardware components in the source device 12, or software programs in the source device 12. They are described as follows:
  • Picture source 16 which may include or may be any kind of picture capture device, for example to capture real-world pictures, and / or any kind of pictures or comments (for screen content encoding, some text on the screen is also considered to be encoded Picture or image) generating device, for example, a computer graphics processor for generating computer animated pictures, or for obtaining and / or providing real world pictures, computer animated pictures (for example, screen content, virtual reality, (VR) pictures), and / or any combination thereof (e.g., augmented reality pictures).
  • the picture source 16 may be a camera for capturing pictures or a memory for storing pictures, and the picture source 16 may also include any type of (internal or external) interface that stores previously captured or generated pictures and / or acquires or receives pictures.
  • the picture source 16 When the picture source 16 is a camera, the picture source 16 may be, for example, a local or integrated camera integrated in the source device; when the picture source 16 is a memory, the picture source 16 may be local or, for example, integrated in the source device Memory.
  • the interface When the picture source 16 includes an interface, the interface may be, for example, an external interface that receives pictures from an external video source.
  • the external video source is, for example, an external picture capture device, such as a camera, an external memory, or an external picture generation device.
  • the interface may be any type of interface according to any proprietary or standardized interface protocol, such as a wired or wireless interface, an optical interface.
  • the picture can be regarded as a two-dimensional array or matrix of sampling points with brightness values.
  • the sampling points in the array may also be called pixels (short for picture element) or pixels.
  • the number of sampling points of the array or picture in the horizontal and vertical directions (or axes) defines the size and / or resolution of the picture.
  • three color components are usually used, that is, a picture can be represented as or contain three sampling arrays.
  • RBG format or color space pictures include corresponding red, green, and blue sampling arrays.
  • each pixel is usually represented in luma / chroma format or color space.
  • a picture in YUV format includes the luminance component indicated by Y (sometimes it can also be indicated by L) and the two indicated by U and V Chroma components.
  • Luma (abbreviated as luma) component Y represents luminance or gray level intensity (for example, both are the same in a grayscale picture), while two chroma (abbreviated as chroma) components U and V represent chroma or color information components .
  • a picture in the YUV format includes a luminance sample array of luminance sample values (Y) and two chrominance sample arrays of chrominance values (U and V).
  • Pictures in RGB format can be converted or converted to YUV format, and vice versa. This process is also called color conversion or conversion.
  • the picture can include only an array of luminance samples.
  • a picture transmitted from the picture source 16 to the picture processor may also be referred to as original picture data 17.
  • the picture source 16 may also be used to determine a position of a chroma sampling point of each picture of the current video sequence.
  • the picture pre-processor 18 is configured to receive the original picture data 17 and perform pre-processing on the original picture data 17 to obtain a pre-processed picture 19 or pre-processed picture data 19.
  • the pre-processing performed by the picture pre-processor 18 may include retouching, color format conversion (eg, conversion from RGB format to YUV format), color correction, or denoising.
  • the picture pre-processor 18 may also be used to determine the position of the chroma sampling points in the current video sequence.
  • An encoder 20 (also referred to as an encoder 20) is configured to receive the preprocessed picture data 19, and use a related prediction mode (such as the intra prediction mode in various embodiments herein) to process the preprocessed picture data 19, Thereby, encoded picture data 21 is provided (the structural details of the encoder 20 will be further described below based on FIG. 2 or FIG. 4 or FIG. 5).
  • the encoder 20 may be configured to execute various embodiments described later to implement the application of the chroma block prediction method described in the present invention on the encoding side.
  • the communication interface 22 can be used to receive the encoded picture data 21, and can transmit the encoded picture data 21 to the destination device 14 or any other device (such as a memory) for storage or direct reconstruction through the link 13.
  • the other device may be any device used for decoding or storage.
  • the communication interface 22 may be used, for example, to encapsulate the encoded picture data 21 into a suitable format, such as a data packet, for transmission on the link 13.
  • the destination device 14 includes a decoder 30.
  • the destination device 14 may further include a communication interface 28, a picture post-processor 32, and a display device 34. They are described as follows:
  • the communication interface 28 may be used to receive the encoded picture data 21 from the source device 12 or any other source, such as a storage device, and the storage device is, for example, an encoded picture data storage device.
  • the communication interface 28 can be used to transmit or receive the encoded picture data 21 through the link 13 between the source device 12 and the destination device 14 or through any type of network.
  • the link 13 is, for example, a direct wired or wireless connection, any
  • the type of network is, for example, a wired or wireless network or any combination thereof, or any type of private and public network, or any combination thereof.
  • the communication interface 28 may be used, for example, to decapsulate the data packets transmitted by the communication interface 22 to obtain the encoded picture data 21.
  • Both the communication interface 28 and the communication interface 22 may be configured as a one-way communication interface or a two-way communication interface, and may be used, for example, to send and receive messages to establish a connection, confirm and exchange any other communication link and / or, for example, encoded picture data Information related to data transmission.
  • a decoder 30 (or called a decoder 30) for receiving the encoded picture data 21 and providing the decoded picture data 31 or the decoded picture 31 (hereinafter, the description of the decoder 30 based on FIG. 3 or FIG. 4 or FIG. 5 will be further described). Structural details).
  • the decoder 30 may be configured to execute various embodiments described later to implement the application of the chroma block prediction method described in the present invention on the decoding side.
  • the picture post-processor 32 is configured to perform post-processing on the decoded picture data 31 (also referred to as reconstructed picture data) to obtain post-processed picture data 33.
  • the post-processing performed by the picture post-processor 32 may include: color format conversion (for example, conversion from YUV format to RGB format), color correction, retouching, or resampling, or any other processing, and may also be used to convert post-processed picture data 33 transmitting to a display device 34.
  • a display device 34 is configured to receive post-processed picture data 33 to display a picture to, for example, a user or a viewer.
  • the display device 34 may be or may include any kind of display for presenting a reconstructed picture, such as an integrated or external display or monitor.
  • the display may include a liquid crystal display (LCD), an organic light emitting diode (OLED) display, a plasma display, a projector, a micro LED display, a liquid crystal on silicon (LCoS), Digital light processor (DLP) or any other display of any kind.
  • FIG. 1A illustrates the source device 12 and the destination device 14 as separate devices
  • the device embodiment may also include both the source device 12 and the destination device 14 or the functionality of both, that is, the source device 12 or Corresponding functionality and destination device 14 or corresponding functionality.
  • the same hardware and / or software, or separate hardware and / or software, or any combination thereof may be used to implement the source device 12 or corresponding functionality and the destination device 14 or corresponding functionality .
  • Source device 12 and destination device 14 may include any of a variety of devices, including any type of handheld or stationary device, such as a notebook or laptop computer, mobile phone, smartphone, tablet or tablet computer, video camera, desktop Computer, set-top box, television, camera, in-vehicle device, display device, digital media player, video game console, video streaming device (e.g. content service server or content distribution server), broadcast receiver device, broadcast transmitter device Etc. and can not use or use any kind of operating system.
  • handheld or stationary device such as a notebook or laptop computer, mobile phone, smartphone, tablet or tablet computer, video camera, desktop Computer, set-top box, television, camera, in-vehicle device, display device, digital media player, video game console, video streaming device (e.g. content service server or content distribution server), broadcast receiver device, broadcast transmitter device Etc. and can not use or use any kind of operating system.
  • Both the encoder 20 and the decoder 30 may be implemented as any of various suitable circuits, for example, one or more microprocessors, digital signal processors (DSPs), application-specific integrated circuits (application-specific integrated circuits) circuit (ASIC), field-programmable gate array (FPGA), discrete logic, hardware, or any combination thereof.
  • DSPs digital signal processors
  • ASIC application-specific integrated circuits
  • FPGA field-programmable gate array
  • the device may store the software's instructions in a suitable non-transitory computer-readable storage medium, and may use one or more processors to execute the instructions in hardware to perform the techniques of the present disclosure. . Any one of the foregoing (including hardware, software, a combination of hardware and software, etc.) can be considered as one or more processors.
  • the video decoding system 10 shown in FIG. 1A is merely an example, and the techniques of the present application may be applicable to a video encoding setting (eg, video encoding or video decoding) that does not necessarily include any data communication between encoding and decoding devices. ).
  • data may be retrieved from local storage, streamed over a network, and the like.
  • the video encoding device may encode the data and store the data to a memory, and / or the video decoding device may retrieve the data from the memory and decode the data.
  • encoding and decoding are performed by devices that do not communicate with each other, but only encode data to and / or retrieve data from memory and decode data.
  • FIG. 1B is an explanatory diagram of an example of a video decoding system 40 including the encoder 20 of FIG. 2 and / or the decoder 30 of FIG. 3 according to an exemplary embodiment.
  • the video decoding system 40 can implement a combination of various technologies in the embodiments of the present invention.
  • the video decoding system 40 may include an imaging device 41, an encoder 20, a decoder 30 (and / or a video encoder / decoder implemented by the logic circuit 47 of the processing unit 46), and an antenna 42 , One or more processors 43, one or more memories 44, and / or a display device 45.
  • the imaging device 41, antenna 42, processing unit 46, logic circuit 47, encoder 20, decoder 30, processor 43, memory 44, and / or display device 45 can communicate with each other.
  • the video decoding system 40 is shown with an encoder 20 and a decoder 30, in different examples, the video decoding system 40 may include only the encoder 20 or only the decoder 30.
  • antenna 42 may be used to transmit or receive an encoded bit stream of video data.
  • the display device 45 may be used to present video data.
  • the logic circuit 47 may be implemented by the processing unit 46.
  • the processing unit 46 may include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like.
  • the video decoding system 40 may also include an optional processor 43.
  • the optional processor 43 may similarly include application-specific integrated circuit (ASIC) logic, a graphics processor, a general-purpose processor, and the like.
  • the logic circuit 47 may be implemented by hardware, such as dedicated hardware for video encoding, etc., and the processor 43 may be implemented by general software, operating system, and the like.
  • the memory 44 may be any type of memory, such as volatile memory (e.g., Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), etc.) or non-volatile memory Memory (for example, flash memory, etc.).
  • volatile memory e.g., Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), etc.
  • non-volatile memory Memory for example, flash memory, etc.
  • the memory 44 may be implemented by a cache memory.
  • the logic circuit 47 may access the memory 44 (eg, for implementing an image buffer).
  • the logic circuit 47 and / or the processing unit 46 may include a memory (eg, a cache, etc.) for implementing an image buffer or the like.
  • the encoder 20 implemented by a logic circuit may include an image buffer (eg, implemented by the processing unit 46 or the memory 44) and a graphics processing unit (eg, implemented by the processing unit 46).
  • the graphics processing unit may be communicatively coupled to the image buffer.
  • the graphics processing unit may include an encoder 20 implemented by a logic circuit 47 to implement various modules discussed with reference to FIG. 2 and / or any other encoder system or subsystem described herein. Logic circuits can be used to perform various operations discussed herein.
  • decoder 30 may be implemented in a similar manner through logic circuit 47 to implement the various modules discussed with reference to decoder 30 of FIG. 3 and / or any other decoder system or subsystem described herein.
  • the decoder 30 implemented by a logic circuit may include an image buffer (implemented by the processing unit 2820 or the memory 44) and a graphics processing unit (eg, implemented by the processing unit 46).
  • the graphics processing unit may be communicatively coupled to the image buffer.
  • the graphics processing unit may include a decoder 30 implemented by a logic circuit 47 to implement the various modules discussed with reference to FIG. 3 and / or any other decoder system or subsystem described herein.
  • the antenna 42 may be used to receive an encoded bit stream of video data.
  • the encoded bitstream may contain data, indicators, index values, mode selection data, etc. related to encoded video frames discussed herein, such as data related to coded segmentation (e.g., transform coefficients or quantized transform coefficients) , (As discussed) optional indicators, and / or data defining code partitions).
  • the video coding system 40 may also include a decoder 30 coupled to the antenna 42 and used to decode the encoded bitstream.
  • the display device 45 is used to present video frames.
  • the decoder 30 may be used to perform the reverse process.
  • the decoder 30 may be used to receive and parse such syntax elements, and decode related video data accordingly.
  • the encoder 20 may entropy encode syntax elements into an encoded video bitstream.
  • the decoder 30 may parse such syntax elements and decode the relevant video data accordingly.
  • the chroma block prediction method described in the embodiment of the present invention is mainly used in the intra prediction process. This process exists in both the encoder 20 and the decoder 30.
  • the encoder 20 and the decoder 30 in the embodiment of the present invention can be, for example, a codec corresponding to a video standard protocol such as H.263, H.264, HEVV, MPEG-2, MPEG-4, VP8, VP9, or a next-generation video standard protocol (such as H.266, etc.).
  • the encoder 20 includes a residual calculation unit 204, a transformation processing unit 206, a quantization unit 208, an inverse quantization unit 210, an inverse transformation processing unit 212, a reconstruction unit 214, a buffer 216, and a loop filter.
  • the prediction processing unit 260 may include an inter prediction unit 244, an intra prediction unit 254, and a mode selection unit 262.
  • the inter prediction unit 244 may include a motion estimation unit and a motion compensation unit (not shown).
  • the encoder 20 shown in FIG. 2 may also be referred to as a hybrid video encoder or a video encoder according to a hybrid video codec.
  • the residual calculation unit 204, the transformation processing unit 206, the quantization unit 208, the prediction processing unit 260, and the entropy encoding unit 270 form the forward signal path of the encoder 20, while the inverse quantization unit 210, the inverse transformation processing unit 212,
  • the constructing unit 214, the buffer 216, the loop filter 220, the decoded picture buffer (DPB) 230, and the prediction processing unit 260 form a backward signal path of the encoder, wherein the backward signal path of the encoder corresponds to To the decoder's signal path (see decoder 30 in Figure 3).
  • the encoder 20 receives the picture 201 or the image block 203 of the picture 201 through, for example, the input 202, for example, a picture in a picture sequence forming a video or a video sequence.
  • the image block 203 can also be called the current picture block or the picture block to be encoded
  • the picture 201 can be called the current picture or the picture to be encoded (especially when the current picture is distinguished from other pictures in video encoding, other pictures such as the same video sequence (Ie previously encoded and / or decoded pictures in the video sequence of the current picture).
  • the embodiment of the encoder 20 may include a dividing unit (not shown in FIG. 2) for dividing the picture 201 into a plurality of blocks, such as an image block 203, and generally divides into a plurality of non-overlapping blocks.
  • the segmentation unit can be used to use the same block size and corresponding raster to define the block size for all pictures in the video sequence, or to change the block size between pictures or subsets or groups of pictures, and split each picture into Corresponding block.
  • the prediction processing unit 260 of the encoder 20 may be used to perform any combination of the segmentation techniques described above.
  • the image block 203 is or can be regarded as a two-dimensional array or matrix of sampling points with brightness values (sampling values), although its size is smaller than the picture 201.
  • the image block 203 may include, for example, one sampling array (for example, a luminance array in the case of a black and white picture 201) or three sampling arrays (for example, one luminance array and two chroma arrays in the case of a color picture) or Any other number and / or category of arrays depending on the color format applied.
  • the number of sampling points in the horizontal and vertical directions (or axes) of the image block 203 defines the size of the image block 203.
  • the encoder 20 shown in FIG. 2 is used to encode a picture 201 block by block, for example, performing encoding and prediction on each image block 203.
  • the residual calculation unit 204 is configured to calculate the residual block 205 based on the picture image block 203 and the prediction block 265 (the other details of the prediction block 265 are provided below). For example, the sample value of the picture image block 203 is subtracted by sample by pixel (pixel by pixel). The sample values of the prediction block 265 are de-predicted to obtain the residual block 205 in the sample domain.
  • the transform processing unit 206 is configured to apply a transform such as discrete cosine transform (DCT) or discrete sine transform (DST) on the sample values of the residual block 205 to obtain transform coefficients 207 in the transform domain.
  • a transform such as discrete cosine transform (DCT) or discrete sine transform (DST)
  • DCT discrete cosine transform
  • DST discrete sine transform
  • the transform coefficient 207 may also be referred to as a transform residual coefficient, and represents a residual block 205 in a transform domain.
  • the transform processing unit 206 may be used to apply an integer approximation of DCT / DST, such as the transform specified for HEVC / H.265. Compared to an orthogonal DCT transform, this integer approximation is usually scaled by a factor. To maintain the norm of the residual blocks processed by the forward and inverse transforms, an additional scaling factor is applied as part of the transform process.
  • the scaling factor is usually selected based on certain constraints, for example, the scaling factor is a power of two used for shift operations, the bit depth of the transform coefficients, the trade-off between accuracy, and implementation cost.
  • a specific scaling factor is specified on the decoder 30 side by, for example, the inverse transform processing unit 212 (and on the encoder 20 side by, for example, the inverse transform processing unit 212 as the corresponding inverse transform), and accordingly, the The 20 side specifies a corresponding scaling factor for the positive transformation through the transformation processing unit 206.
  • the quantization unit 208 is used to quantize the transform coefficient 207, for example, by applying scalar quantization or vector quantization to obtain the quantized transform coefficient 209.
  • the quantized transform coefficient 209 may also be referred to as a quantized residual coefficient 209.
  • the quantization process can reduce the bit depth associated with some or all of the transform coefficients 207. For example, n-bit transform coefficients may be rounded down to m-bit transform coefficients during quantization, where n is greater than m.
  • the degree of quantization can be modified by adjusting the quantization parameter (QP). For scalar quantization, for example, different scales can be applied to achieve finer or coarser quantization.
  • a smaller quantization step size corresponds to a finer quantization, while a larger quantization step size corresponds to a coarser quantization.
  • An appropriate quantization step size can be indicated by a quantization parameter (QP).
  • the quantization parameter may be an index of a predefined set of suitable quantization steps.
  • smaller quantization parameters may correspond to fine quantization (smaller quantization step size)
  • larger quantization parameters may correspond to coarse quantization (larger quantization step size)
  • Quantization may include division by a quantization step size and corresponding quantization or inverse quantization performed, for example, by inverse quantization 210, or may include multiplication by a quantization step size.
  • Embodiments according to some standards such as HEVC may use quantization parameters to determine the quantization step size.
  • the quantization step size can be calculated using a fixed-point approximation using an equation containing division based on the quantization parameter. Additional scaling factors may be introduced for quantization and inverse quantization to restore the norm of the residual block that may be modified due to the scale used in the fixed-point approximation of the equation for the quantization step size and quantization parameter.
  • inverse transform and inverse quantization scales can be combined.
  • a custom quantization table can be used and signaled from the encoder to the decoder in, for example, a bitstream. Quantization is a lossy operation, where the larger the quantization step, the greater the loss.
  • the inverse quantization unit 210 is configured to apply the inverse quantization of the quantization unit 208 on the quantized coefficients to obtain the inverse quantized coefficients 211. For example, based on or using the same quantization step size as the quantization unit 208, apply the quantization scheme applied by the quantization unit 208 Inverse quantization scheme.
  • the dequantized coefficient 211 may also be referred to as a dequantized residual coefficient 211, which corresponds to the transform coefficient 207, although the loss due to quantization is usually different from the transform coefficient.
  • the inverse transform processing unit 212 is used to apply an inverse transform of the transform applied by the transform processing unit 206, for example, an inverse discrete cosine transform (DCT) or an inverse discrete sine transform (DST), so that Obtain an inverse transform block 213.
  • the inverse transform block 213 may also be referred to as an inverse transform inverse quantized block 213 or an inverse transform residual block 213.
  • the reconstruction unit 214 (for example, the summer 214) is used to add the inverse transform block 213 (that is, the reconstructed residual block 213) to the prediction block 265 to obtain the reconstructed block 215 in the sample domain.
  • the sample values of the reconstructed residual block 213 are added to the sample values of the prediction block 265.
  • a buffer unit 216 (or simply "buffer" 216), such as a line buffer 216, is used to buffer or store the reconstructed block 215 and corresponding sample values, for example, for intra prediction.
  • the encoder may be used to use any unfiltered reconstructed block and / or corresponding sample values stored in the buffer unit 216 for any category of estimation and / or prediction, such as intra-frame prediction.
  • an embodiment of the encoder 20 may be configured such that the buffer unit 216 is used not only for storing the reconstructed block 215 for intra prediction 254, but also for the loop filter unit 220 (not shown in FIG. 2). Out), and / or, for example, to make the buffer unit 216 and the decoded picture buffer unit 230 form a buffer.
  • Other embodiments may be used to use the filtered block 221 and / or blocks or samples from the decoded picture buffer 230 (neither shown in FIG. 2) as the input or basis for the intra prediction 254.
  • the loop filter unit 220 (or simply "loop filter” 220) is configured to filter the reconstructed block 215 to obtain the filtered block 221, so as to smoothly perform pixel conversion or improve video quality.
  • the loop filter unit 220 is intended to represent one or more loop filters, such as a deblocking filter, a sample-adaptive offset (SAO) filter, or other filters such as a bilateral filter, Adaptive loop filters (adaptive loop filters, ALF), or sharpening or smoothing filters, or cooperative filters.
  • the loop filter unit 220 is shown as an in-loop filter in FIG. 2, in other configurations, the loop filter unit 220 may be implemented as a post-loop filter.
  • the filtered block 221 may also be referred to as a filtered reconstructed block 221.
  • the decoded picture buffer 230 may store the reconstructed encoded block after the loop filter unit 220 performs a filtering operation on the reconstructed encoded block.
  • An embodiment of the encoder 20 may be used to output loop filter parameters (e.g., sample adaptive offset information), for example, directly output or by the entropy coding unit 270 or any other
  • the entropy coding unit outputs after entropy coding, for example, so that the decoder 30 can receive and apply the same loop filter parameters for decoding.
  • the decoded picture buffer (DPB) 230 may be a reference picture memory that stores reference picture data for the encoder 20 to encode video data.
  • DPB 230 can be formed by any of a variety of memory devices, such as dynamic random access (DRAM) (including synchronous DRAM (SDRAM), magnetoresistive RAM (MRAM), and resistive RAM (resistive RAM, RRAM)) or other types of memory devices.
  • DRAM dynamic random access
  • MRAM magnetoresistive RAM
  • RRAM resistive RAM
  • the DPB 230 and the buffer 216 may be provided by the same memory device or separate memory devices.
  • a decoded picture buffer (DPB) 230 is used to store the filtered block 221.
  • the decoded picture buffer 230 may be further used to store other previous filtered blocks of the same current picture or different pictures such as previously reconstructed pictures, such as the previously reconstructed and filtered block 221, and may provide a complete previous Reconstruction is the decoded picture (and corresponding reference blocks and samples) and / or part of the reconstructed current picture (and corresponding reference blocks and samples), for example for inter prediction.
  • a decoded picture buffer (DPB) 230 is used to store the reconstructed block 215.
  • a prediction processing unit 260 also referred to as a block prediction processing unit 260, is used to receive or obtain an image block 203 (current image block 203 of the current picture 201) and reconstructed picture data, such as the same (current) picture from the buffer 216 Reference samples and / or reference picture data 231 of one or more previously decoded pictures from the decoded picture buffer 230, and for processing such data for prediction, providing a block that can be The prediction block 265 of the intra prediction block 255.
  • the mode selection unit 262 may be used to select a prediction mode (such as an intra or inter prediction mode) and / or a corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.
  • a prediction mode such as an intra or inter prediction mode
  • a corresponding prediction block 245 or 255 used as the prediction block 265 to calculate the residual block 205 and reconstruct the reconstructed block 215.
  • An embodiment of the mode selection unit 262 may be used to select a prediction mode (e.g., selected from those prediction modes supported by the prediction processing unit 260) that provides the best match or minimum residual (minimum residual means Better compression in transmission or storage), or provide minimal signaling overhead (minimum signaling overhead means better compression in transmission or storage), or consider or balance both.
  • the mode selection unit 262 may be used to determine a prediction mode based on rate distortion optimization (RDO), that is, to select a prediction mode that provides the minimum code rate distortion optimization, or to select a prediction mode whose related code rate distortion meets the prediction mode selection criteria .
  • RDO rate distortion optimization
  • the prediction processing unit 260 may be further configured to divide the image block 203 into smaller block partitions or sub-blocks, for example, iteratively uses quad-tree (QT) segmentation, binary-tree (BT) segmentation Or triple-tree (TT) segmentation, or any combination thereof, and for performing predictions for, for example, block partitions or each of the sub-blocks, where the mode selection includes selecting the tree structure of the segmented image block 203 and selecting the application A prediction mode for each of a block partition or a sub-block.
  • QT quad-tree
  • BT binary-tree
  • TT triple-tree
  • the inter prediction unit 244 may include a motion estimation (ME) unit (not shown in FIG. 2) and a motion compensation (MC) unit (not shown in FIG. 2).
  • the motion estimation unit is configured to receive or obtain a picture image block 203 (current picture image block 203 of the current picture 201) and a decoded picture 231, or at least one or more previously reconstructed blocks, for example, one or more other / different
  • the reconstructed block of the previously decoded picture 231 is used for motion estimation.
  • the video sequence may include the current picture and the previously decoded picture 31, or in other words, the current picture and the previously decoded picture 31 may be part of the picture sequence forming the video sequence or form the picture sequence.
  • the encoder 20 may be used to select a reference block from multiple reference blocks of the same or different pictures in multiple other pictures, and provide a reference picture and / or a reference to a motion estimation unit (not shown in FIG. 2).
  • the offset (spatial offset) between the position of the block (X, Y coordinates) and the position of the current block is used as an inter prediction parameter. This offset is also called a motion vector (MV).
  • the motion compensation unit is configured to obtain an inter prediction parameter, and obtain an inter prediction block 245 based on or using the inter prediction parameter to perform inter prediction.
  • Motion compensation performed by a motion compensation unit may include taking out or generating a prediction block based on a motion / block vector determined through motion estimation (possibly performing interpolation on sub-pixel accuracy). Interpolation filtering can generate additional pixel samples from known pixel samples, potentially increasing the number of candidate prediction blocks that can be used to encode picture blocks.
  • the motion compensation unit 246 may locate the prediction block pointed to by the motion vector in a reference picture list.
  • the motion compensation unit 246 may also generate syntax elements associated with the blocks and video slices for use by the decoder 30 when decoding picture blocks of the video slices.
  • the intra prediction unit 254 is configured to obtain a picture image block 203 (current picture block) of the same picture and one or more previously reconstructed blocks, such as reconstructed neighboring blocks, to perform intra estimation.
  • the encoder 20 may be used to select an intra prediction mode (such as selecting an LM prediction mode) from a plurality of intra prediction modes.
  • the intra prediction mode of the chroma component of the image may include five types: Planar mode, vertical mode, horizontal mode, DC mode, and corresponding luma component mode. (DM).
  • the intra prediction mode of the chroma component of an image also includes a cross component prediction mode (CCP), and a cross component prediction mode (CCP). It is called cross component intra prediction mode (CCIP), or cross component linear mode (CCLM) prediction mode.
  • CCLM prediction mode can also be referred to as linear model mode (LM mode for short).
  • LM mode is a chroma intra prediction method that uses the texture correlation between luminance and chroma.
  • Directional prediction mode refers to mapping the reference pixel to a pixel position in the current block according to a certain direction (using the intra mode index index) to obtain the predicted value of the current pixel, or, for each pixel in the current block, Point, and its position is mapped back to the reference pixel in a certain direction (using intra mode index index), and the pixel value of the corresponding reference pixel is the predicted value of the current pixel.
  • DC prediction uses the average value of reference pixels as the predicted value of pixels in the current block
  • Planar mode uses the pixel values of reference pixels directly above and to the left of the current pixel and the upper right of the current block. Derive the predicted value of the current pixel with the pixel value of the lower left reference pixel.
  • the intra prediction unit 254 is further configured to determine the intra prediction block 255 based on the intra prediction parameters of the intra prediction mode as selected. In any case, after selecting the intra prediction mode for the block, the intra prediction unit 254 is further configured to provide the intra prediction parameters to the entropy encoding unit 270, that is, to provide an indication of the selected intra prediction mode for the block. Information.
  • the intra prediction unit 254 may further include a filter set, where the filter set includes multiple filter types, and different filter types represent different luminance block downsampling algorithms, and each filter type Corresponds to a chroma point sampling position, respectively.
  • the intra prediction unit 254 may be further configured to determine a sampling position of a chroma point of the current video sequence, determine a filter type used in the current encoding based on the sample position of the chroma point, and generate an indication information based on the filter type.
  • the instruction information is used to indicate the type of filter used in the down-sampling process of the luminance image in the LM prediction mode when the current video sequence is encoded or decoded (such as when the picture 201 or the image block 203 is encoded or reconstructed).
  • the intra prediction unit 254 is further configured to provide the entropy coding unit 270 with indication information of a filter type.
  • the intra prediction unit 254 may transmit a syntax element to the entropy encoding unit 270, where the syntax element includes intra prediction parameters (such as an intra prediction mode selected for the current block prediction after traversing multiple intra prediction modes, for example, LM mode, instructions) and filter type instructions.
  • intra prediction parameters such as an intra prediction mode selected for the current block prediction after traversing multiple intra prediction modes, for example, LM mode, instructions
  • filter type instructions such as filter type instructions.
  • the intra prediction parameter may not be carried in the syntax element.
  • the decoding end 30 may directly use the LM prediction mode for decoding by default.
  • the intra prediction unit 254 may be used to perform any combination of intra prediction techniques described below.
  • the entropy coding unit 270 is configured to apply an entropy coding algorithm or scheme (for example, a variable length coding (VLC) scheme, a context adaptive VLC (context adaptive VLC, CAVLC) scheme, an arithmetic coding scheme, and a context adaptive binary arithmetic Coding (context, adaptive binary coding, CABAC), syntax-based context-adaptive binary arithmetic coding (SBAC), probability interval partitioning entropy (PIPE) coding, or other entropy Encoding method or technique) applied to one or all of the quantized residual coefficients 209, inter prediction parameters, intra prediction parameters, and / or loop filter parameters (or not applied) to obtain
  • VLC variable length coding
  • CAVLC context adaptive VLC
  • CABAC syntax-based context-adaptive binary arithmetic coding
  • PIPE probability interval partitioning entropy
  • the encoded picture data 21 is output in the form of, for example, an encoded bit stream 21.
  • the encoded bitstream may be transmitted to the decoder 30 or archived for later transmission or retrieval by the decoder 30.
  • the entropy encoding unit 270 may also be used to entropy encode other syntax elements of the current video slice that is being encoded.
  • the non-transform-based encoder 20 may directly quantize the residual signal without a transform processing unit 206 for certain blocks or frames.
  • the encoder 20 may have a quantization unit 208 and an inverse quantization unit 210 combined into a single unit.
  • the encoder 20 may be configured to: set a value of a filter type according to a sampling point position type of the chroma block, and generate a first value for indicating the filter type according to the value.
  • An indication information, the filter type corresponds to a filter in a filter set, and then the first indication information is coded as a piece of information in a syntax element into a code stream and carried in the encoded image In data 21.
  • the encoder 20 may be further configured to: select an LM mode from a plurality of intra prediction modes, and then generate second instruction information, where the second instruction information is used to indicate the linear mode; and then The second indication information is coded into a code stream as one piece of information in a syntax element, and is carried in the encoded image data 21.
  • the encoder 20 may be further configured to: in the LM mode, determine a filter in a filter set corresponding to the filter type according to the first indication information. ; Then, according to the filter, down-sampling the first luma block to obtain a second luma block, the first luma block being a luma block corresponding to the current chroma block; obtaining a template chroma point and template luminance Point, the template chrominance point includes a plurality of chrominance pixel points adjacent to the current chrominance block, and the template luminance point is obtained by downsampling a plurality of luminance pixel points adjacent to the first luminance block; Then, a linear model coefficient is obtained according to the template chroma point and the template brightness point; and a predicted value of the current chroma block is obtained according to the second luma block and the linear model coefficient.
  • the decoder 30 is configured to receive, for example, the encoded picture data 21 encoded by the encoder 20 to obtain a decoded picture 231.
  • the decoder 30 receives video data from the encoder 20, such as an encoded video bitstream and associated syntax elements representing picture blocks of the encoded video slice.
  • the decoder 30 includes an entropy decoding unit 304, an inverse quantization unit 310, an inverse transform processing unit 312, a reconstruction unit 314 (such as a summer 314), a buffer 316, a loop filter 320, The decoded picture buffer 330 and the prediction processing unit 360.
  • the prediction processing unit 360 may include an inter prediction unit 344, an intra prediction unit 354, and a mode selection unit 362.
  • the decoder 30 may perform a decoding pass that is substantially reciprocal to the encoding pass described with reference to the encoder 20 of FIG. 2.
  • the entropy decoding unit 304 is configured to perform entropy decoding on the encoded picture data 21 to obtain, for example, quantized coefficients 309 and / or decoded encoding parameters (not shown in FIG. 3), for example, inter prediction, intra prediction parameters , (Filtered) any or all of the loop filter parameters and / or other syntax elements.
  • the entropy decoding unit 304 is further configured to forward the inter prediction parameters, the intra prediction parameters, and / or other syntax elements to the prediction processing unit 360.
  • the decoder 30 may receive syntax elements at a video slice level and / or a video block level.
  • the inverse quantization unit 310 may be functionally the same as the inverse quantization unit 110
  • the inverse transformation processing unit 312 may be functionally the same as the inverse transformation processing unit 212
  • the reconstruction unit 314 may be functionally the same as the reconstruction unit 214
  • the buffer 316 may be functionally
  • the loop filter 320 may be functionally the same as the loop filter 220
  • the decoded picture buffer 330 may be functionally the same as the decoded picture buffer 230.
  • the prediction processing unit 360 may include an inter prediction unit 344 and an intra prediction unit 354.
  • the inter prediction unit 344 may be functionally similar to the inter prediction unit 244 and the intra prediction unit 354 may be functionally similar to the intra prediction unit 254.
  • the prediction processing unit 360 is generally used to perform block prediction and / or obtain prediction blocks 365 from the encoded data 21, and to receive or obtain prediction-related parameters and / or Information about the selected prediction mode.
  • the intra-prediction unit 354 of the prediction processing unit 360 is used for the intra-prediction mode based on signal representation, Data to generate a prediction block 365 for a picture block of the current video slice.
  • the inter-prediction unit 344 e.g., a motion compensation unit
  • the other syntax elements generate a prediction block 365 for a video block of the current video slice.
  • a prediction block may be generated from a reference picture in a reference picture list.
  • the decoder 30 may construct a reference frame list using a default construction technique based on the reference pictures stored in the DPB 330: List 0 and List 1.
  • the prediction processing unit 360 is configured to determine prediction information for a video block of a current video slice by analyzing a motion vector and other syntax elements, and use the prediction information to generate a prediction block for a current video block that is being decoded. For example, the prediction processing unit 360 uses some of the received syntax elements to determine a prediction mode (e.g., intra or inter prediction) of a video block used to encode a video slice, an inter prediction slice type (e.g., B slice, P slice or GPB slice), construction information for one or more of the reference picture lists for the slice, motion vectors for each inter-coded video block for the slice, each warp for the slice The inter-prediction status and other information of the inter-coded video block to decode the video block of the current video slice.
  • a prediction mode e.g., intra or inter prediction
  • an inter prediction slice type e.g., B slice, P slice or GPB slice
  • construction information for one or more of the reference picture lists for the slice motion vectors for each inter-coded video block
  • the inverse quantization unit 310 may be used for inverse quantization (ie, inverse quantization) of the quantized transform coefficients provided in the bitstream and decoded by the entropy decoding unit 304.
  • the inverse quantization process may include using the quantization parameters calculated by the encoder 20 for each video block in the video slice to determine the degree of quantization that should be applied and also to determine the degree of inverse quantization that should be applied.
  • the inverse transform processing unit 312 is configured to apply an inverse transform (for example, an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process) to the transform coefficients to generate a residual block in the pixel domain.
  • an inverse transform for example, an inverse DCT, an inverse integer transform, or a conceptually similar inverse transform process
  • Reconstruction unit 314 (e.g., summer 314) is used to add inverse transform block 313 (i.e., reconstructed residual block 313) to prediction block 365 to obtain reconstructed block 315 in the sample domain, such as by The sample values of the reconstructed residual block 313 are added to the sample values of the prediction block 365.
  • the loop filter unit 320 (during or after the encoding cycle) is used to filter the reconstructed block 315 to obtain the filtered block 321 so as to smoothly perform pixel conversion or improve video quality.
  • the loop filter unit 320 may be used to perform any combination of filtering techniques described below.
  • the loop filter unit 320 is intended to represent one or more loop filters, such as a deblocking filter, a sample-adaptive offset (SAO) filter, or other filters such as a bilateral filter, Adaptive loop filters (adaptive loop filters, ALF), or sharpening or smoothing filters, or cooperative filters.
  • the loop filter unit 320 is shown as an in-loop filter in FIG. 3, in other configurations, the loop filter unit 320 may be implemented as a post-loop filter.
  • the decoded video block 321 in a given frame or picture is then stored in a decoded picture buffer 330 that stores reference pictures for subsequent motion compensation.
  • the decoder 30 is used, for example, to output a decoded picture 31 through an output 332 for presentation to or review by a user.
  • the decoder 30 may be used to decode the compressed bit stream.
  • the decoder 30 may generate an output video stream without the loop filter unit 320.
  • the non-transform-based decoder 30 may directly inversely quantize the residual signal without the inverse transform processing unit 312 for certain blocks or frames.
  • the decoder 30 may have an inverse quantization unit 310 and an inverse transform processing unit 312 combined into a single unit.
  • the decoder 30 is configured to parse the bitstream to obtain first indication information and second indication information, where the second indication information is used to indicate the intra prediction used for the currently decoded chroma block.
  • the mode is LM mode, and the first indication information is used to indicate a filter type; according to a filter corresponding to the filter type, the first luminance block is down-sampled to obtain a second luminance block, and the first luminance block is obtained.
  • FIG. 4 is a schematic structural diagram of a video decoding device 400 (such as a video encoding device 400 or a video decoding device 400) according to an embodiment of the present invention.
  • Video coding device 400 is adapted to implement the embodiments described herein.
  • the video coding device 400 may be a video decoder (such as the decoder 30 of FIG. 1A) or a video encoder (such as the encoder 20 of FIG. 1A).
  • the video decoding device 400 may be one or more components in the decoder 30 of FIG. 1A or the encoder 20 of FIG. 1A described above.
  • the video decoding device 400 includes: an entry port 410 and a receiving unit (Rx) 420 for receiving data, a processor, a logic unit or a central processing unit (CPU) 430 for processing data, and a transmitter unit for transmitting data (Tx) 440 and egress port 450, and a memory 460 for storing data.
  • the video decoding device 400 may further include a photoelectric conversion component and an electro-optic (EO) component coupled with the entrance port 410, the receiver unit 420, the transmitter unit 440, and the exit port 450 for an exit or entrance of an optical signal or an electric signal.
  • EO electro-optic
  • the processor 430 is implemented by hardware and software.
  • the processor 430 may be implemented as one or more CPU chips, cores (eg, multi-core processors), FPGAs, ASICs, and DSPs.
  • the processor 430 is in communication with the ingress port 410, the receiver unit 420, the transmitter unit 440, the egress port 450, and the memory 460.
  • the processor 430 includes a decoding module 470 (eg, an encoding module 470 or a decoding module 470).
  • the encoding / decoding module 470 implements the embodiments disclosed herein to implement the chroma block prediction method provided by the embodiments of the present invention.
  • the encoding / decoding module 470 implements, processes, or provides various encoding operations.
  • the function of the video decoding device 400 is substantially improved through the encoding / decoding module 470, and the transition of the video decoding device 400 to different states is affected.
  • the encoding / decoding module 470 is implemented with instructions stored in the memory 460 and executed by the processor 430.
  • the memory 460 includes one or more magnetic disks, tape drives, and solid-state hard disks, which can be used as overflow data storage devices for storing programs when these programs are selectively executed, and for storing instructions and data read during program execution.
  • the memory 460 may be volatile and / or non-volatile, and may be a read-only memory (ROM), a random access memory (RAM), a random content-addressable memory (TCAM), and / or a static state. Random access memory (SRAM).
  • FIG. 5 is a simplified block diagram of an apparatus 500 that can be used as either or both of the source device 12 and the destination device 14 in FIG. 1A according to an exemplary embodiment.
  • the device 500 may implement the technology of the present application.
  • the device 500 for implementing chroma block prediction may be in the form of a computing system including a plurality of computing devices, or in a mobile phone, tablet computer, laptop computer, notebook computer, desktop The form of a single computing device, such as a computer.
  • the processor 502 in the apparatus 500 may be a central processing unit.
  • the processor 502 may be any other type of device or multiple devices capable of manipulating or processing information, existing or to be developed in the future.
  • speed and efficiency advantages can be achieved using more than one processor.
  • the memory 504 in the device 500 may be a read-only memory (ROM) device or a random access memory (RAM) device. Any other suitable type of storage device can be used as the memory 504.
  • the memory 504 may include code and data 506 accessed by the processor 502 using the bus 512.
  • the memory 504 may further include an operating system 508 and an application program 510, which contains at least one program that permits the processor 502 to perform the methods described herein.
  • the application program 510 may include applications 1 to N, and applications 1 to N further include a video encoding application that performs the methods described herein.
  • the device 500 may also include additional memory in the form of a slave memory 514, which may be, for example, a memory card for use with a mobile computing device. Because a video communication session may contain a large amount of information, this information may be stored in whole or in part in the slave memory 514 and loaded into the memory 504 for processing as needed.
  • the apparatus 500 may also include one or more output devices, such as a display 518.
  • the display 518 may be a touch-sensitive display combining a display and a touch-sensitive element operable to sense a touch input.
  • the display 518 may be coupled to the processor 502 through a bus 512.
  • other output devices may be provided that allow the user to program or otherwise use the device 500, or provide other output devices as an alternative to the display 518.
  • the display can be implemented in different ways, including through a liquid crystal display (LCD), a cathode-ray tube (CRT) display, a plasma display, or a light emitting diode diode (LED) displays, such as organic LED (OLED) displays.
  • LCD liquid crystal display
  • CTR cathode-ray tube
  • plasma display a plasma display
  • LED light emitting diode diode
  • OLED organic LED
  • the apparatus 500 may further include or be in communication with an image sensing device 520, such as a camera or any other image sensing device 520 that can or will be developed in the future to sense an image, such as An image of a user running the device 500.
  • the image sensing device 520 may be placed directly facing a user of the running apparatus 500.
  • the position and optical axis of the image sensing device 520 may be configured such that its field of view includes an area immediately adjacent to the display 518 and the display 518 is visible from the area.
  • the device 500 may also include or be in communication with a sound sensing device 522, such as a microphone or any other sound sensing device that can or will be developed in the future to sense the sound near the device 500.
  • the sound sensing device 522 may be placed directly facing the user of the operating device 500 and may be used to receive a sound, such as a voice or other sound, emitted by the user when the device 500 is running.
  • the processor 502 and the memory 504 of the apparatus 500 are shown in FIG. 5 as being integrated in a single unit, other configurations may be used.
  • the operation of the processor 502 may be distributed among multiple directly-coupled machines (each machine has one or more processors), or distributed in a local area or other network.
  • the memory 504 may be distributed among multiple machines, such as a network-based memory or a memory among multiple machines running the apparatus 500.
  • the bus 512 of the device 500 may be formed by multiple buses.
  • the slave memory 514 may be directly coupled to other components of the device 500 or may be accessed through a network, and may include a single integrated unit, such as one memory card, or multiple units, such as multiple memory cards. Therefore, the apparatus 500 can be implemented in various configurations.
  • the YUM image (or YCbCr image) and the LM mode of chrominance component intra prediction according to the embodiment of the present invention are further described below.
  • the existing video is generally a color video.
  • the image in the color video also contains the chrominance component (U, V). Therefore, such an image can also be called a YUV image. Therefore, when encoding a YUV image, in addition to encoding the luminance component, it is also necessary to encode the chrominance component. Studies have shown that the human eye is more sensitive to brightness and less sensitive to color. Therefore, in coding, in order to save storage space and improve coding efficiency, the luminance component is sampled at full resolution, and the chrominance component may not be sampled at full resolution.
  • the general video sequence images have YUV images in 4: 4: 4 format, YUV images in 4: 2: 2 format, and YUV in 4: 2: 0 format. Images, etc.
  • FIG. 6 exemplarily shows 4: 4: 4 format, 4: 2: 2 format, and 4: 2: 0 format, where the cross ( ⁇ ) in the figure represents the sampling point of the luminance component.
  • the circle (0) in the illustration indicates the sampling point of the chrominance component.
  • the 4: 4: 4 format indicates that the chroma component is not down-sampled
  • the 4: 4: 4 format is the format with the highest resolution of the chroma component, that is, the data in the adjacent 4 pixels has 4 Y, 4 U, 4 V.
  • the 4: 2: 2 format indicates that the chrominance component is down-sampled horizontally to the luminance component by 2: 1, without vertical down-sampling.
  • each line contains four Y sampling points. In other words, there are 4 Y, 2 U, and 2 V data in the adjacent 4 pixels.
  • the 4: 2: 0 format means that the chrominance component is subjected to a horizontal downsampling of 2: 1 relative to the luminance component, and a vertical downsampling of 2: 1.
  • the 4: 2: 0 format is the format with the lowest resolution of chrominance components, and it is also the most common format.
  • chroma sampling is only half of the luminance sampling in each row (that is, the horizontal direction) and only half of the luminance sampling in each column (that is, the vertical direction).
  • the chrominance component of the image block is an image block of the size MxN. For example, if the resolution of an image block is 720 * 480, then the resolution of the luminance component of the image block is 720 * 480, and the resolution of the chrominance component of the image block is 360 * 240.
  • FIG. 7 exemplarily shows the correlation between the position of the luminance sampling point of the luminance point and the position of the six different chrominance sampling points of the chrominance point.
  • These six different types of chrominance sampling point positions are respectively Type 0 (type 0), type 1 (type 1), type 2 (type 2), type 3 (type 3), type 4 (type 4) and type 5 (type 5).
  • the luminance component of the current image block to be processed can also be referred to as a luminance block (or the current luminance block corresponding to the luma block, or the first luminance block, or the luminance component block, or the luma block).
  • the chrominance component of an image block can also be called the current chrominance block (also called a chrominance block, or a chrominance component block, or a chroma block).
  • intra prediction of chroma components uses the boundary pixels of neighboring reconstructed blocks around the current chroma block as the reference pixels of the current chroma block.
  • the reference is based on a certain prediction mode. Pixels are mapped to pixel points in the current chroma block as the predicted values of pixels in the current chroma block. The difference is that since the texture of the chrominance component is generally simpler, the number of chroma component intra prediction modes is generally less than the number of luma component prediction modes.
  • the chroma component intra prediction mode also includes a cross component prediction (CCP) mode.
  • CCP cross component prediction
  • the CCP mode may be called cross-component intra prediction (CCIP), or cross-component linear prediction mode (CCLM). , Or simply referred to as linear model mode (LM mode).
  • CCIP cross-component intra prediction
  • CCLM cross-component linear prediction mode
  • LM mode linear model mode
  • LM mode is a chroma intra prediction method that takes advantage of the texture correlation between luminance and chroma. It uses the reconstructed luma component to derive the current chroma block prediction value according to a linear model, thereby providing a more accurate prediction value for the chroma component.
  • the LM mode can be expressed as:
  • ⁇ and ⁇ are linear model coefficients, and pred C (i, j) is the predicted value of the chroma pixel at the position (i, j); rec L ′ (i, j) is the current luma block corresponding to the luma block.
  • the luminance values at the (i, j) position are reconstructed as pixel values.
  • the resolution of the luminance component is 4 times that of the chrominance component.
  • the luminance component needs to be the same as the chrominance component.
  • the down-sampling method down-samples to the resolution of the chrominance component and then uses it.
  • FIG. 8 respectively shows a luma block corresponding to the current chroma block (that is, the luminance component of the image block) in a 4: 2: 0 format YUV image, and its adjacent upper and left references Pixel point, down-sampled luma block (that is, the down-sampled luma component of the image block, or the second luma block) and its adjacent top and left reconstructed reference pixels, the current chroma block (that is, the Chrominance component) and the reconstructed reference pixels on its adjacent top and left sides.
  • the current chroma block that is, the Chrominance component
  • the resolution of the luma block corresponding to the current chroma block is 2W * 2H
  • the resolution of the down-sampled luma block is W * H
  • the resolution of the current chroma block is W * H. That is, the luminance block and the neighboring reference pixel points of the luminance block are down-sampled to the resolution of the chrominance component to obtain the down-sampled luminance block.
  • the adjacent reference pixel points of the down-sampled luma block and the adjacent reference pixel points of the current chroma block form a one-to-one correspondence relationship.
  • a template represents a set of luma points or chroma points used to calculate linear model coefficients.
  • the set of luma samples used to calculate linear model coefficients can also be referred to as template luma points.
  • Multiple luminance pixel points adjacent to the luma block are obtained by performing a downsampling operation (because there may not be a luminance sample value at a position matching the template chroma point in the luminance image).
  • the set of chroma points used to calculate the coefficients of the linear model may also be referred to as a template chroma point, and the template chroma point includes a plurality of reconstructed chroma pixel points adjacent to the current chroma block.
  • the template chroma points specifically include chroma pixel points adjacent to the current chroma block in one row or multiple rows above, and the current chroma block is adjacent to one column to the left or more to the left.
  • the template luminance point and the template chrominance point correspond one-to-one, and the values of the sampling points constitute a value pair.
  • the chroma points of the template are the chroma pixels in a row adjacent to the top of the current chroma block, and a column of chroma pixels.
  • the template luminance point includes a row of luminance pixel points that match the position of each chrominance point in the template chrominance point, and a left column of luminance pixels.
  • the chroma points of the template are two rows of chroma pixels adjacent to the top of the current chroma block, and two columns of chroma pixels on the left.
  • the template luminance point includes two rows of luminance pixel points and two columns of luminance pixel points that match the position of each chrominance point in the template chrominance point.
  • the specific implementation of the template chroma point and the template luma point may also be various.
  • the template chroma point may include only the adjacent left column or the left side of the current chroma block. Multiple columns of chroma pixels.
  • the template luminance points and the template chrominance points correspond one-to-one, and only include one or more columns of luminance pixel points that match the position.
  • the template chrominance points may also include only chrominance pixel points adjacent to the current chrominance block in one row or multiple rows.
  • the template luminance point and the template chrominance point correspond one-to-one, and only include one or more rows of luminance pixel points that match the position.
  • the template brightness point is obtained by performing a downsampling operation on a plurality of brightness pixel points adjacent to the brightness block, and a method for performing a downsampling operation on the template brightness point is exemplarily described below.
  • FIG. 11 is an exemplary diagram of the positional relationship between the positions of some chroma sampling points and the positions of luma sampling points.
  • a 4: 2: 0 format YUV image if the top left corner of the luminance image is the origin of the coordinates of the luminance sampling point, and the top left corner of the chroma image is the origin of the chroma sampling point coordinates, then (xb, yb The position of the sampling point corresponding to the brightness image is (2 * xb, 2 * yb + 0.5).
  • a plurality of brightness pixel points adjacent to the brightness block may be selected first, for example, the brightness blocks are adjacent
  • the positions of the sampling points of multiple brightness pixels are (2 * xb, 2 * yb), (2 * xb-1,2 * yb), (2 * xb + 1,2 * yb), (2 * xb , 2 * yb + 1), (2 * xb-1,2 * yb + 1), (2 * xb + 1,2 * yb + 1), according to these positions, corresponding to the brightness pixel values in the brightness image
  • a plurality of luminance pixels can be down-sampled according to the following formula to obtain the value LC (xb, yb) of the luminance point corresponding to the (xb, yb) sampling point position in the template luminance point:
  • the existing sampling method is downsampling based on a fixed filter. That is, for the images in various video sequences, in the existing LM mode, regardless of the position of the chroma sampling points, a fixed down-sampling filter is used, without considering the different video sequences in practice. Possible different chroma sampling point positions and the effect of different chroma sampling point positions on the luminance downsampling filter.
  • the embodiments of the present invention propose a chroma for the LM mode based on the system and equipment described above.
  • the block prediction method is first described from the perspective of the encoding end. Referring to FIG. 12, the method includes but is not limited to the following steps:
  • Step 701 Determine the intra prediction mode used when predicting the current chroma block is the LM mode.
  • the encoder can only preset the LM mode in the intra prediction, that is, in this case, the encoder directly determines the currently used intra prediction mode as the LM mode, and then continues to perform steps 702 to 704. .
  • multiple intra prediction modes may also be preset.
  • the multiple intra prediction modes include an LM mode, and the encoding end traverses the multiple intra prediction modes. , Determine that the optimal intra prediction mode in the prediction of the current chrominance block is the LM mode. In this case, start to execute subsequent steps such as step 702 to step 704.
  • the encoding end may further set second instruction information, where the second instruction information is used to indicate the LM mode, so that the second instruction information is encoded into the code stream in a subsequent step 704.
  • Step 702 Determine a filter type according to a sampling point position type of a current chroma block.
  • the brightness downsampling filter used is not fixed, but is determined by the type of the sampling point position of the current chroma block. To decide. Each type of sampling point position of the current chroma block has a corresponding filter type.
  • the design can be referred to as design one).
  • the six types of sampling point positions include: type0, type1, type2 , Type3, type4, and type5.
  • the six types of sampling point positions there are six types of brightness downsampling filters, which can be referred to as: filter 0, filter 1, filter 2, filter 3, filter 4, Filter 5.
  • the down-sampling algorithms of these filters can be set as follows:
  • LC (xb, yb) (2 * L (2 * xb, 2 * yb) + L (2 * xb-1,2 * yb) + L (2 * xb + 1,2 * yb) + 2 * L (2 * xb, 2 * yb + 1) + L (2 * xb-1,2 * yb + 1) + L (2 * xb + 1,2 * yb + 1) +4) >> 3.
  • LC (xb, yb) (L (2 * xb, 2 * yb) + L (2 * xb + 1,2 * yb) + L (2 * xb, 2 * yb + 1) + L (2 * xb + 1,2 * yb + 1) +2) >> 2.
  • LC (xb, yb) (2 * L (2 * xb, 2 * yb) + 2 * L (2 * xb + 1,2 * yb) + L (2 * xb, 2 * yb-1) + L (2 * xb + 1,2 * yb-1) + L (2 * xb, 2 * yb + 1) + L (2 * xb + 1,2 * yb + 1) +4) >> 3.
  • LC (xb, yb) (2 * L (2 * xb, 2 * yb + 1) + 2 * L (2 * xb + 1,2 * yb + 1) + L (2 * xb, 2 * yb) + L (2 * xb + 1,2 * yb) + L (2 * xb, 2 * yb + 2) + L (2 * xb + 1,2 * yb + 2) +4) >> 3.
  • two types of sampling point positions can also be designed (this design can be referred to as design two), that is, these two This type of sampling point location only includes: type0, type2.
  • this type of sampling point location only includes: type0, type2.
  • the down-sampling algorithms of these filters can be set as follows:
  • LC (xb, yb) (2 * L (2 * xb, 2 * yb) + L (2 * xb-1,2 * yb) + L (2 * xb + 1,2 * yb) + 2 * L (2 * xb, 2 * yb + 1) + L (2 * xb-1,2 * yb + 1) + L (2 * xb + 1,2 * yb + 1) +4) >> 3.
  • the embodiments of the present invention may also be other designs, such as designing three types of chroma point sampling positions, and three types of filtering corresponding to the three chroma point sampling positions, respectively.
  • Devices, etc. are not limited here.
  • the encoding end can first determine the sampling point position type of the current chroma block, and then determine the corresponding filter type according to the sampling point position type of the current chroma block, that is, when determining the LM mode to predict the current chroma block.
  • Step 703 Set first indication information, where the first indication information is used to indicate the filter type.
  • An embodiment of the present invention adds a sequence parameter set (SPS) parameter, and the value of this SPS parameter will be used to indicate the type of the brightness down-sampling filter in the LM mode when the current video sequence is encoded or decoded.
  • this parameter can be set based on the sampling position of the chroma points of the current sequence.
  • the first indication information may be set according to the type of the filter, and the first indication information includes the value of the SPS parameter, which is used to indicate the luminance downsampling filter used in the prediction of the chroma block during encoding or decoding. Types of.
  • the name of the newly added SPS parameter syntax element may be: “lm_mode_downsampling_filter_type_idc”, and lm_mode_downsampling_filter_type_idc is used to specify the downsampling filter type of the LM mode.
  • the sequence parameters The set can be designed as follows:
  • the value of lm_mode_downsampling_filter_type_idc is in the range of 0 to 5. Different values correspond to different filters, for example: value 0 corresponds to filter 0, value 1 corresponds to filter 1, value 2 corresponds to filter 2, value 3 corresponds to filter 3, value 4 corresponds to filter 4, and value 5 corresponds to filter Device 5, and so on.
  • value 0 corresponds to filter 0
  • value 1 corresponds to filter 1
  • value 2 corresponds to filter 2
  • value 3 corresponds to filter 3
  • value 4 corresponds to filter 4
  • value 5 corresponds to filter Device 5, and so on.
  • the above-mentioned setting of each value and the corresponding relationship between each value and the filter are merely examples and are not limiting.
  • filter 0 filter 2
  • sequence parameter set can be designed as follows:
  • the value of lm_mode_downsampling_filter_type_idc can be 0 or 1. Different values correspond to different filters. For example, the value 0 corresponds to filter 0, the value 1 corresponds to filter 2, and so on. Of course, the above-mentioned setting of each value and the corresponding relationship between each value and the filter are merely examples and are not limiting.
  • Step 704 Program the first instruction information into a code stream, and send the code stream to a decoding end.
  • the second instruction information set in the above step 701 may be programmed into the code stream and then sent to the decoding end.
  • the second instruction information is used to indicate the LM mode, so as to instruct the decoding end to adopt the LM mode.
  • the above embodiment only describes the process of encoding and code stream sending at the encoding end. According to the foregoing description, those skilled in the art understand that the encoding end can also implement other methods described in the embodiments of the present invention in other links. For example, in the prediction of the chrominance block at the encoding end, the specific implementation of the reconstruction process of the chrominance block can refer to the related method described later at the decoding end, which will not be repeated here.
  • the encoder can determine the luminance down-sampling filter used by the current luminance block according to the type of the sampling position of the current chroma point, and indicate the information (such as newly added SPS parameters Value) to specify the type of downsampling filter to the decoder.
  • both the encoding end and the decoding end can obtain a filter that matches the sampling position of the chroma point, which is conducive to taking into account the fact that different video sequences may have different positions of the chroma sampling point, and ensuring that the position of the down-sampled luminance point and the The chroma sampling point positions are consistent, thereby improving the coding accuracy and coding efficiency of the coding end.
  • an embodiment of the present invention provides another chroma block prediction method, which is described from the perspective of a decoder.
  • the method includes, but is not limited to, the following steps:
  • Step 801 Parse the bitstream to obtain the first indication information.
  • the decoding end may obtain the first indication information by analyzing a sequence parameter set (SPS) parameter in the code stream.
  • SPS sequence parameter set
  • the SPS parameter in the code stream may specifically be a newly-added SPS parameter.
  • the first indication information is used to indicate a filter type.
  • the decoding end analyzes the code stream transmitted by the encoding end to obtain first indication information for indicating the type of the filter.
  • first indication information for indicating the type of the filter.
  • Encoder and decoder can design the same filter type.
  • the encoding end is designed with 6 filter types (corresponding to the position of 6 chroma sampling points), the decoding end is also designed with 6 filter types, and the downsampling algorithms of the 6 filter types at the decoding end are respectively related to The encoding ends are the same: filter 0, filter 1, filter 2, filter 3, filter 4, filter 5.
  • the first instruction information received by the decoding end is used to indicate one of the six filter types.
  • the first indication information is the SPS parameter lm_mode_downsampling_filter_type_idc, and when the SPS parameter has a value of 2, it indicates that the first indication information indicates that the filter type is filter 2.
  • the encoding end is designed with 2 types of filters (corresponding to the positions of 2 chroma sampling points), the decoding end is also designed with 2 types of filters, and the 2 types of filtering at the decoding end are down-sampled respectively. Consistent with the encoding end, respectively: filter 0, filter 2.
  • the first instruction information received by the decoding end is used to indicate one of the two filter types.
  • the first indication information is the SPS parameter lm_mode_downsampling_filter_type_idc. When the SPS parameter has a value of 0, it indicates that the first indication information indicates that the filter type is filter 0.
  • the first indication information is used to indicate a sampling point position of the current chroma block, and a sampling point position of the current chroma block is associated with the filter type. Therefore, the decoding end can determine the filter type according to the sampling point position of the current chroma block.
  • the first indication information may be specifically used to indicate a sampling point position type of the current chroma block, and accordingly, a sampling point position type of the current chroma block is associated with the filter type. Therefore, the decoding end may determine the filter type according to the position type of the sampling point of the current chroma block.
  • the encoding end is designed with 2 filter types (corresponding to 2 chroma sampling point positions), the decoding end is also designed with 2 filter types, and the downsampling algorithms of the 2 filter types at the decoding end are respectively
  • the encoding ends are the same: filter 0 and filter 2.
  • the first instruction information received by the decoding end is used to indicate one of the positions of the two chroma sampling points.
  • the first indication information is the SPS parameter lm_mode_downsampling_filter_type_idc. When the SPS parameter has a value of 0, it indicates the position of the first chroma sampling point, for example, type0.
  • the decoding end may directly determine the filter type as the filter 0 according to the first sampling point position type type0. For another example, when the value of the SPS parameter is 1, it indicates the position of the second chroma sampling point, such as type2. Since the type of the sampling point is associated with the type of the filter, the decoder can directly determine the position of the second sampling point. Type type2, determine the filter type as filter2.
  • the second indication information may also be obtained by parsing the bitstream, and the second indication information is used to instruct the decoding end to decode the intra prediction used by the current chroma block.
  • the mode is the LM mode, so that the decoder determines that the intra prediction of the current image of the video sequence adopts the LM mode, and further, performs subsequent steps 802-805.
  • Step 802 Perform a downsampling operation on the first luma block according to the filter corresponding to the filter type to obtain a second luma block, where the first luma block is a luma block corresponding to the current chroma block.
  • a filter corresponding to the first indication information may be used to down-sample the current chroma block luminance block (ie, the first luminance block) of the current image to obtain the down-sampled luminance block (ie, the second luminance block).
  • the brightness downsampling filter used is filter 0.
  • the sampling algorithm is as follows:
  • the filter 0 by using the filter 0 to down-sample the first luminance block, the value of each luminance pixel in the second luminance block can be obtained.
  • the decoder is designed with two filter types (such as filter 0 and filter 2), and the value indicated by the first indication information is 1, the brightness down-sampling filter used is filter 2.
  • the sampling algorithm is as follows:
  • the filter 2 by using the filter 2 to down-sample the first luminance block, the value of each luminance pixel in the second luminance block can be obtained.
  • Step 803 Obtain a template chroma point and a template brightness point.
  • the template chrominance point includes a plurality of chrominance pixel points adjacent to the current chrominance block, and the template luminance point is obtained by performing a downsampling operation on the plurality of chrominance pixel points adjacent to the first luminance block. obtain.
  • step 803 reference may be made to the related descriptions of the embodiments in FIG. 9 and FIG. 10 above. For brevity of the description, details are not described herein again.
  • step 802 may be performed before or after step 803, and step 802 and step 803 may also be performed simultaneously.
  • Step 804 Obtain linear model coefficients ⁇ and ⁇ according to the template chromaticity point and the template brightness point.
  • the linear model coefficients ⁇ and ⁇ can be obtained by using a method of least squares.
  • a system of linear equations may be constructed using the template chroma points of the down-sampled luma block as shown in FIG. 9 and the template chroma points shown in FIG. 9.
  • the number of adjacent reference pixels in the template chroma point or template luma point is N, and use L (n) and C (n) to represent the value of the nth luma pixel and the chroma pixel respectively .
  • the linear linear model coefficients ⁇ and ⁇ are:
  • the extreme value method can be used to obtain the linear model coefficients ⁇ and ⁇ .
  • the number of adjacent reference pixels in the template chroma point or template luma point is N, and use L (n) and C (n) to represent the value of the nth luma pixel and the chroma pixel respectively.
  • L (n) and C (n) constitute pixel value pairs
  • the set of pixel value pairs can be obtained: ⁇ (L 0 , C 0 ), (L 1 , C 1 ), (L 2 , C 2 ) ... (L n , C n )... (L N-1 , C N-1 ) ⁇ , where N is the number of adjacent pixels of the current chroma block used to determine the coefficients of the linear model.
  • FIG. 14 shows the distribution of a set of pixel value pairs in a luminance-chrominance coordinate system. Find the value pair corresponding to the maximum brightness value L max and the minimum brightness value L min in the above pixel value pair set.
  • the embodiment of the present invention is not limited to the use of Any way to derive the linear model coefficients ⁇ and ⁇ of the LM mode based on the template chroma points and the template luminance points.
  • Step 805 Obtain a predicted value of the current chrominance block according to the second luminance block and the linear model coefficient. It can be understood that after rec L ′ (i, j) and the linear model coefficients ⁇ and ⁇ are obtained, according to the algorithm formula of the LM mode:
  • the prediction value pred C (i, j) of each chroma pixel in the current chroma block can be obtained.
  • the decoder can use the indication information in the code stream (such as the value of the newly added SPS parameter). To determine the filter used in downsampling the luma block corresponding to the current chroma block in the LM mode.
  • a filter matching the sampling position of the chroma point can be obtained, which is beneficial to take into account the situation that different video sequences may have different positions of the chroma sampling point, and ensure that the position of the down-sampled luminance point is consistent with the position of the chroma sampling point. Sex.
  • an embodiment of the present invention provides another chroma block prediction method, which is described from the perspective of a decoding end.
  • the embodiment of FIG. 15 is different from the embodiment of FIG. 13 described above.
  • Step 903 of the embodiment in FIG. 15 is different from step 803 of the embodiment in FIG. 13. The method is briefly described as follows:
  • Step 901 Parse the bitstream to obtain first indication information, where the first indication information is used to indicate a filter type.
  • first indication information is used to indicate a filter type.
  • Step 902 According to a filter corresponding to the filter type, perform a downsampling operation on the first luma block to obtain a second luma block.
  • the first luma block is a luma block corresponding to the current chroma block.
  • the two luminance blocks represent a set after the luminance pixels in the first luminance block are down-sampled.
  • step 802 refers to the description of step 802 in the embodiment of FIG. 13, and details are not described herein again.
  • Step 903 Obtain a template chromaticity point, and obtain a template luminance point according to the first instruction information.
  • a filter corresponding to the filter type may be used to perform multiple brightness pixel points adjacent to the first brightness block. Downsampling operation to obtain the template brightness point.
  • the brightness downsampling filter used is filter 0.
  • the sampling algorithm is as follows:
  • the filter 0 can be used to perform a down-sampling operation on a plurality of brightness pixel points adjacent to the first brightness block to obtain the value of each brightness pixel point in the template brightness point.
  • the decoder is designed with two filter types (such as filter 0 and filter 2), and the value indicated by the first indication information is 1, the brightness down-sampling filter used is filter 2.
  • the sampling algorithm is as follows:
  • the filter 2 may be used to perform a down-sampling operation on a plurality of brightness pixel points adjacent to the first brightness block to obtain the value of each brightness pixel point in the template brightness point.
  • the template chrominance point includes a plurality of chrominance pixel points adjacent to the current chrominance block.
  • the template chrominance point includes a plurality of chrominance pixel points adjacent to the current chrominance block.
  • Step 904 Obtain linear model coefficients ⁇ and ⁇ according to the template chromaticity point and the template brightness point. For specific implementation, refer to the description of step 804 in the embodiment of FIG. 13, and details are not described herein again.
  • Step 905 Obtain a predicted value of the current chrominance block according to the second luminance block and the linear model coefficient. For specific implementation, reference may be made to the description of step 805 in the embodiment of FIG. 13, and details are not described herein again.
  • the decoder can use the indication information in the code stream (such as the newly added SPS parameter) during the downsampling process of deriving the template brightness points and the downsampling process for the current block. Value) to determine the filter used when the luminance block corresponding to the current chrominance block is down-sampled in the LM mode.
  • the indication information in the code stream such as the newly added SPS parameter
  • Value the filter used when the luminance block corresponding to the current chrominance block is down-sampled in the LM mode.
  • FIG. 16 shows a block diagram of a content supply system 3100 for implementing a content distribution service.
  • This content provisioning system 3100 includes a capture device 3102, a terminal device 3106, and optionally a display 3126.
  • the capture device 3102 communicates with the terminal device 3106 through a communication link 3104.
  • the communication link may include the communication channel 13 described above.
  • the communication link 3104 includes, but is not limited to, WIFI, Ethernet, wired, wireless (3G / 4G / 5G), USB, or any combination thereof.
  • the capture device 3102 generates data, and can encode the data by an encoding method as shown in the above embodiments.
  • the capture device 3102 may distribute the data to a streaming media server (not shown in the figure), the server encodes the data and transmits the encoded data to the terminal device 3106.
  • the capturing device 3102 includes, but is not limited to, a camera, a smartphone or a tablet computer, a computer or a notebook computer, a video conference system, a PDA, a vehicle-mounted device, or a combination of any of them.
  • the capture device 3102 may include the source device 12 as described above.
  • the video encoder 20 included in the capture device 3102 may actually perform a video encoding process.
  • the audio encoder included in the capture device 3102 can actually perform audio encoding processing.
  • the capture device 3102 distributes the encoded video data and the encoded audio data by multiplexing the encoded video data and the encoded audio data together.
  • encoded audio data and encoded video data are not multiplexed.
  • the capture device 3102 distributes the encoded audio data and the encoded video data to the terminal device 3106, respectively.
  • the terminal device 310 receives and reproduces the encoded data.
  • the terminal device 3106 can be a device with data receiving and recovery capabilities, such as a smart phone or tablet 3108, a computer or laptop 3110, a network video recorder (NVR) / digital video recorder (DVR) 3112 , TV 3114, set-top box (STB) 3116, video conference system 3118, video surveillance system 3120, personal digital assistant (PDA) 3122, in-vehicle equipment 3124, or above devices capable of decoding the above-mentioned encoded data Any combination of them etc.
  • the terminal device 3106 may include the destination device 14 as described above.
  • the encoded data includes a video
  • the video decoder 30 included in the terminal device is prioritized to perform video decoding.
  • the audio decoder included in the terminal device is prioritized to perform audio decoding processing.
  • the terminal device can feed the decoded data to its display.
  • NVR network video recorders
  • DVR digital video recorders
  • TV 3114 TV 3114
  • PDA personal digital assistant
  • the terminal device can feed the decoded data to its display.
  • an external display 3126 is connected to receive and display decoded data.
  • an image encoding device or an image decoding device as shown in the above embodiment can be used.
  • FIG. 17 is a diagram illustrating a configuration of an example of the terminal device 3106.
  • the protocol processing unit 3202 analyzes the transmission protocol of the stream.
  • the protocols include, but are not limited to, Real-Time Streaming Protocol (RTSP), HyperText Transfer Protocol (HTTP), HTTP Live Streaming Protocol (HLS), MPEG-DASH , Real-time Transport Protocol (RTP), Real-Time Messaging Protocol (RTMP), or any combination thereof.
  • a stream file is generated.
  • the file is output to the demultiplexing unit 3204.
  • the demultiplexing unit 3204 may separate the multiplexed data into encoded audio data and encoded video data. As described above, for other practical scenarios, such as in a video conference system, the encoded audio data and the encoded video data are not multiplexed. In this case, the encoded data is transmitted to the video decoder 3206 and the audio decoder 3208 without passing through the demultiplexing unit 3204.
  • the video decoder 3206 includes the video decoder 30 as described in the above embodiment, and decodes the video ES to generate a video frame by using the decoding method as shown in the above embodiment, and feeds this data to the synchronization unit 3212.
  • the audio decoder 3208 decodes the audio ES to generate an audio frame, and feeds this data to the synchronization unit 3212.
  • the video frames may be stored in a buffer (not shown in the figure) before the video frames are fed to the synchronization unit 3212.
  • the audio frames may be stored in a buffer (not shown in the figure) before the audio frames are fed to the synchronization unit 3212.
  • the synchronization unit 3212 synchronizes the video frame and the audio frame, and provides the video / audio to the video / audio display 3214.
  • the synchronization unit 3212 synchronizes the presentation of video and audio information.
  • the information may be encoded in syntax using timestamps related to the presentation of the encoded audio and visual data and timestamps related to the transmission of the data stream itself.
  • the subtitle decoder 3210 decodes the subtitles, synchronizes the subtitles with the video frame and the audio frame, and provides the video / audio / subtitle to the video / audio / subtitle display 3216.
  • the present invention is not limited to the above-mentioned system, and the image encoding device or the image decoding device in the above-mentioned embodiment can be incorporated into other systems, such as a car system.
  • the computer program product includes one or more computer instructions.
  • the computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device.
  • the computer instructions may be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium.
  • the computer instructions may be from a network site, computer, server, or data center.
  • the computer-readable storage medium may be any available medium that can be accessed by a computer, and may also be a data storage device such as a server, a data center, and the like that includes one or more available medium integration.
  • the usable medium may be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape, etc.), an optical medium (such as a DVD, etc.), or a semiconductor medium (such as a solid state hard disk), and the like.

Abstract

本发明提供了色度块预测方法及设备，该方法包括：解析码流获得第一指示信息，第一指示信息用于指示滤波器类型；根据滤波器类型对应的滤波器，对第一亮度块进行下采样，获得第二亮度块，第一亮度块是当前色度块对应的亮度块；获取模板色度点和模板亮度点，模板色度点包括当前色度块相邻的多个色度像素点，模板亮度点通过对第一亮度块相邻的多个亮度像素点进行下采样操作获得；根据模板色度点和模板亮度点，获得线性模型系数；根据第二亮度块和线性模型系数，获得当前色度块的预测值。

Description

色度块预测方法以及设备 技术领域
本发明涉及视频编码领域，尤其涉及色度块预测方法以及设备。
背景技术
随着互联网科技的迅猛发展以及人们物质精神文化的日益丰富，在互联网中针对视频的应用需求尤其是针对高清视频的应用需求越来越多，而高清视频的数据量非常大，要想高清视频能在带宽有限的互联网中传输，必须首先解决的问题就是高清视频压缩编码问题。目前，国际上有两个国际组织专门进行视频编码标准的制定工作，即ISO/IEC下的MPEG和ITU-T的VCEG。成立于1986年的MPEG专门负责制定多媒体领域内的相关标准，主要应用于存储、广播电视、因特网或无线网上的流媒体等。ITU-T则主要制定面向实时视频通信领域的视频编码标准，如视频电话、视频会议等应用。在过去的几十年里，国际上已经成功制定了面向各种应用的视频编码标准，主要包括：用于VCD的MPEG-1标准，用于DVD和DVB的MPEG-2标准，用于视频会议的H.261标准以及H.263标准、H.264标准，允许对任意形状的对象编码的MPEG-4标准、HEVC标准等等。
当前广泛使用的视频编码标准H.264/AVC(记为H.264)和H.265/HEVC(记为H.265)，均以图像块为基本单元进行各种类型的编码操作，例如基于图像块的预测、变换、熵编码等等。图像块指一个二维采样点阵列，即由像素点组成的WxH大小的阵列(W可以等于H，也可以不等于H)，并且已知各个像素点位置的像素值。
一般的视频编码过程主要包括帧内预测(Intra Prediction)、帧间预测(Inter Prediction)、变换(Transform)、量化(Quantization)、熵编码(Entropy encode)、环内滤波(in-loop filtering)等环节。将图像划分为图像块之后进行帧内和帧间预测，并且在得到残差之后进行变换量化，最终进行熵编码并输出码流。
其中，帧内预测利用当前图像内已重建区域内像素点的像素值对当前块内像素点的像素值进行预测，一般使用当前块的周围已重建的相邻块的像素导出当前块内像素的预测值。例如，在H.264或者H.265中，一般使用周围相邻块的边界像素(靠近当前块的一侧边界)作为当前块的参考像素，并基于这些参考像素按照某种方法导出当前块内像素的预测值。帧内预测模式例如为DC(或均值)模式和平面模式的非方向性模式，或者为H.265中定义的方向性模式。
利用帧内预测得到预测信息之后，根据当前编码块内像素点的像素值减去对应的预测信息便得到残差信息，然后利用离散余弦变换(Discrete Cosine Transformation，DCT)等方法对残差信息进行变换，再使用量化熵编码得到码流。预测信号加上重建残差信号之后需进一步进行滤波操作，进而得到重建信号，并将其作为后续编码的参考信号。
解码则相当于编码的逆过程。首先利用熵解码反量化反变换得到残差信息，解码码流确定当前块使用的是帧内还是帧间预测。如果是帧内编码，则利用当前图像内周围已重建区域内像素点的像素值按照所使用的帧内预测方法构建预测信息。使用预测信息加上残差信息经过滤波操作便可以得到重建信息。
现有的视频一般为彩色视频，彩色视频中的图像除了含有亮度分量以外，还含有色度分量。因此，除了对亮度分量进行编码，还需要对色度分量进行编码。如何提高在帧内预测中色度分量的编码效率，目前仍然是一项技术挑战。
发明内容
本发明实施例提供了色度块预测方法以及设备，能够提高内预测中色度分量(色度块)的编码效率。
第一方面，本发明实施例提供了一种色度块预测方法，从编码端的角度描述，该方法可应用于对当前色度块的帧内预测中，采用的帧内预测模式为线性模型模式(linear model mode，简称LM模式)，该方法可包括：根据当前色度块的采样点位置类型确定滤波器类型，该滤波器类型由当前色度块的采样点位置类型来决定的，每一种当前色度块的采样点位置类型皆有对应的滤波器类型；设置第一指示信息，所述第一指示信息用于指示所述滤波器类型；将所述第一指示信息编入码流以便于后续发送至解码端。
可以看到，本发明实施例中，编码器可以根据当前色度点的采样位置类型来决定当前亮度块采用的亮度下采样滤波器，并通过指示信息来向解码器指定下采样滤波器的类型。从而保证编码端和解码端都可以得到与色度点采样位置相匹配的滤波器，提高编码端的编码准确度和编码效率。
基于第一方面，在可能的实施例中，可设计6种采样点位置类型，这6种采样点位置类型包括：type0、type1、type2、type3、type4和type5。那么，对应于所述6种采样点位置类型，分别有6种类型的亮度下采样滤波器：滤波器0、滤波器1、滤波器2、滤波器3、滤波器4、滤波器5。也就是说，当前色度块的采样点位置类型可为6种采样点位置类型中的一种。通过设置这些滤波器，保证编码端、解码端得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，从而提高编码端的编码准确度和编码效率。
基于第一方面，在可能的实施例中，考虑到目前type0以及type2的色度点采样位置最为常见，也可设计2种采样点位置类型，即这2种采样点位置类型只包括：type0、type2。那么，对应于所述2种采样点位置类型，分别有2种类型亮度下采样滤波器：滤波器0、滤波器2。也就是说，当前色度块的采样点位置类型可为2种采样点位置类型中的一种。通过设置这些滤波器，可在满足大部分常见编码需要的同时，提高编码端的编码准确度和编码效率。
基于第一方面，在可能的实施例中，可新增一个序列参数集(sequence parameter set，SPS)参数，此SPS参数的值将用于指示当前视频序列编码或者解码时，LM模式中的亮度下采样滤波器的类型。在编码端，此参数可以基于当前序列的色度点的采样位置设置。具体的，可根据滤波器类型设置第一指示信息，所述第一指示信息即包括该SPS参数的值，用于指示编码或者解码时对色度块预测中所采用的亮度下采样滤波器的类型。
基于第一方面，在可能的实施例中，在编码端的帧内预测中，也可预设多种帧内预测模式，所述多种帧内预测模式中包括LM模式，编码端遍历所述多种帧内预测模式，确定对当前色度块的预测中最优的帧内预测模式为LM模式，此外，编码端还可设置第二指示信息， 所述第二指示信息用于指示所述LM模式，并将第二指示信息编入码流，以便于解码端也采用LM模式进行帧内预测，提高编码效率。
基于第一方面，在可能的实施例中，在预测块的构建阶段，编码端还可以根据所述第一指示信息，确定所述滤波器类型对应的滤波器；根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样，获得第二亮度块，所述第一亮度块是所述当前色度块对应的亮度块；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点下采样获得；根据所述模板色度点和所述模板亮度点，获得线性模型系数；根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
第二方面，本发明实施例提供了一种色度块预测方法，该方法可应用于对当前色度块的帧内预测中，采用的帧内预测模式为LM模式。该方法包括：解析码流获得第一指示信息，所述第一指示信息用于指示滤波器类型；根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块，第二亮度块的亮度像素点的位置与当前色度块的色度像素点的位置具有一致性；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；根据所述模板色度点和所述模板亮度点，获得线性模型系数；根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
可以看到，本发明实施例中，对于LM模式，解码端在当前块的下采样过程中，可通过码流中的指示信息来确定当前色度块对应的亮度块下采样时采用的滤波器。从而可以得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，提高编码效率和编码准确度。
具体的，本发明实施例中，可将用于计算线性模型系数的相邻上边和左边称为模板(template)。模板表示用于计算线性模型系数的亮度点或色度点的集合，其中，用于计算线性模型系数的亮度点(luma sample)的集合又可称为模板亮度点，所述模板亮度点通过对亮度块相邻的多个亮度像素点进行下采样操作而获得(因为亮度图像中，与模板色度点相匹配的位置可能并没有亮度采样值)。用于计算线性模型系数的色度点(chroma sample)的集合又可称为模板色度点，所述模板色度点包括所述当前色度块相邻的多个已重建色度像素点。
基于第二方面，在可能的实施例中，所述模板色度点具体包括所述当前色度块相邻上边一行或者上边多行的色度像素点，以及，所述当前色度块相邻左边一列或者左边多列的色度像素点。模板亮度点以及模板色度点一一对应，并且采样点的值构成值对。
基于第二方面，在可能的实施例中，模板色度点为当前色度块相邻上边一行色度像素点，以及一列色度像素点。相应的，模板亮度点包括与模板色度点中的各个色度点位置相匹配的一行亮度像素点，以及左边一列亮度像素点。
基于第二方面，在可能的实施例中，模板色度点为当前色度块相邻上边两行色度像素点，以及左边两列色度像素点。相应的，模板亮度点包括与模板色度点中的各个色度点位置相匹配的两行亮度像素点，以及两列亮度像素点。
基于第二方面，在可能的实施例中，所述模板色度点也可只包括所述当前色度块相邻左边一列或者左边多列的色度像素点。模板亮度点以及模板色度点一一对应，只包括位置匹配的一列或者多列的亮度像素点。
基于第二方面，在可能的实施例中，所述模板色度点也可只包括所述当前色度块相邻上边一行或者上边多行的色度像素点。模板亮度点以及模板色度点一一对应，只包括位置匹配的一行或者多行的亮度像素点。
基于第二方面，在可能的实施例中，对于模板亮度点，由于第一指示信息指示了滤波器类型，则可利用该滤波器类型对应的滤波器，对所述第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点。这样，使得解码端在导出模板亮度点的下采样过程以及对当前块的下采样过程中采用同样的滤波器，提高处理效率。
举例来说，解码端设计有6种滤波器类型，且当前第一指示信息指示的值为0，则采用的亮度下采样滤波器为滤波器0，可利用该滤波器0，对第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点中的各个亮度像素点的值。
基于第二方面，在可能的实施例中，在解析码流的环节中，还可通过解析所述码流获得第二指示信息，所述第二指示信息用于指示解码端解码当前色度块采用的帧内预测模式为LM模式，从而解码端确定对视频序列的当前图像的帧内预测采用LM模式。
基于第二方面，在可能的实施例中，所述方法用于解码视频序列中的当前图像块，所述当前图像块包括所述第一亮度块和所述当前色度块，所述视频序列中的图像为4:2:0格式或者4:2:2格式。
基于第二方面，在可能的实施例中，编码端和解码端可对滤波器类型进行相同的设计。例如，编码端设计有6种滤波器类型(对应于6种色度采样点位置)，解码端也设计有6种滤波器类型，且所述解码端的6种滤波器类型的下采样算法分别与编码端一致。又例如，编码端设计有2种滤波器类型(对应于2种色度采样点位置)，解码端也设计有2种滤波器类型，且所述解码端的2种滤波器类型的下采样算法分别与编码端一致
基于第二方面，在可能的实施例中，所述第一指示信息即包括该SPS参数的值，用于指示编码或者解码时对色度块预测中所采用的亮度下采样滤波器的类型。
基于第二方面，在可能的实施例中，根据所述模板色度点和所述模板亮度点，获得线性模型系数包括：可根据所述模板色度点和所述模板亮度点，利用最小二乘法的方法来求取线性模型系数α和β。
基于第二方面，在可能的实施例中，根据所述模板色度点和所述模板亮度点，获得线性模型系数包括：可根据所述模板色度点和所述模板亮度点，利用极值的方法来求取线性模型系数α和β。
第三方面，该方法可应用于对当前色度块的帧内预测中，可从解码端的角度进行描述，采用的帧内预测模式例如为LM模式。方法包括：根据当前色度块的采样点位置确定滤波器类型；根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；根据所述模板色度点和所述模板亮度点， 获得线性模型系数；根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
可以看到，本发明实施例中，编码器可以根据当前色度块的采样点位置确定当前亮度块采用的亮度下采样滤波器，从而可以得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，提高编码效率和编码准确度。
基于第三方面，在可能的实施例中，所述根据当前色度块的采样点位置确定滤波器类型之前包括：解析码流获得第一指示信息，所述第一指示信息用于指示所述当前色度块的采样点位置。所述当前色度块的采样点位置可关联所述滤波器类型。
可以看到，本发明实施例中，编码器可以根据第一指示信息确定当前色度点的采样点位置，从而可以得到与色度点采样点位置相匹配的滤波器。由于编码端和解码端都可以得到与色度点采样位置相匹配的滤波器，提高编码端的编码准确度和编码效率。
基于第三方面，在可能的实施例中，所述当前色度块的采样点位置例如可以由所述当前色度块的采样点位置类型来确定。所述当前色度块的采样点位置类型可关联所述滤波器类型。
在一种实现中，所述当前色度块的采样点位置类型为以下采样点位置类型中的至少一种：采样点位置类型type0、采样点位置类型type2。
在又一种实现中，所述当前色度块的采样点位置类型为以下采样点位置类型中的至少一种：采样点位置类型type0、采样点位置类型type1、采样点位置类型type2、采样点位置类型type3、采样点位置类型type4、采样点位置类型type5。
基于第三方面，在可能的实施例中，所述解析码流获得第一指示信息包括：解析码流中的序列参数集(SPS)参数，获得所述第一指示信息。实施本实施例，编码端可通过某一SPS参数来向解码端指示当前色度块的采样点位置类型，即相当于向解码端指定了下采样滤波器的类型，进而保证编码端和解码端都可以得到与色度点采样位置相匹配的滤波器。
第四方面，本发明实施例提供了一种用于编码视频数据的设备，所述设备包括存储器以及耦合的编码器，其中，存储器，用于存储码流形式的视频数据；编码器，用于根据当前色度块的采样点位置类型确定滤波器类型；设置第一指示信息，所述第一指示信息用于指示所述滤波器类型；将所述第一指示信息编入码流。具体的，所述设备可用于实现第一方面所描述的方法。
第五方面，本发明实施例提供了一种用于解码视频数据的设备，所述设备包括存储器以及耦合的解码器，其中，存储器，用于存储码流形式的视频数据；解码器，用于解析码流获得第一指示信息，所述第一指示信息用于指示滤波器类型；根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；根据所述模板色度点和所述模板亮度点，获得线性模型系数；根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。具体的，所述设备可用于实现第二方面所描述的方法。
第六方面，本发明实施例提供了一种用于解码视频数据的设备，所述设备包括存储器以及耦合的解码器，其中，存储器，用于存储码流形式的视频数据；解码器，用于根据当前色度块的采样点位置类型确定滤波器类型；根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；根据所述模板色度点和所述模板亮度点，获得线性模型系数；根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。具体的，所述设备可用于实现第三方面所描述的方法。
第七方面，本发明实施例提供了一种编码设备，包括：相互耦合的非易失性存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第一方面所描述的方法。
第八方面，本发明实施例提供了一种解码设备，包括：相互耦合的非易失性存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第二方面所描述的方法。
第九方面，本发明实施例提供了一种解码设备，包括：相互耦合的非易失性存储器和处理器，所述处理器调用存储在所述存储器中的程序代码以执行第三方面所描述的方法。
第十方面，本发明实施例提供了一种系统，所述系统包括如第四方面所述的设备和如第五方面所述的设备，或者，所述系统包括如第四方面所述的设备和如第六方面所述的设备。
第十一方面，本发明实施例提供了又一种系统，所述系统包括如第七方面所述的编码设备和如第八方面所述的解码设备，或者所述系统包括如第七方面所述的编码设备和如第九方面所述的解码设备。
第十二方面，本发明实施例提供了一种非易失性计算机可读存储介质；所述计算机可读存储介质用于存储第一方面所述方法的实现代码。所述程序代码被计算设备执行时，所述计算设备用于第一方面所述方法。
第十三方面，本发明实施例提供了又一种非易失性计算机可读存储介质；所述计算机可读存储介质用于存储第二方面或第三方面所述方法的实现代码。所述程序代码被计算设备执行时，所述用户设备用于第二方面或第三方面所述方法。
第十四方面，本发明实施例提供了一种计算机程序产品；该计算机程序产品包括程序指令，当该计算机程序产品被计算设备执行时，该控制器执行前述第一方面所述方法。该计算机程序产品可以为一个软件安装包，在需要使用前述第一方面的任一种可能的设计提供的方法的情况下，可以下载该计算机程序产品并在控制器上执行该计算机程序产品，以实现第一方面所述方法。
第十五方面，本发明实施例提供了又一种计算机程序产品。该计算机程序产品包括程序指令，当该计算机程序产品被用户设备执行时，该控制器执行前述第二方面或第三方面的任一种可能的设计提供的方法。该计算机程序产品可以为一个软件安装包，在需要使用前述第二方面或第三方面的任一种可能的设计提供的方法的情况下，可以下载该计算机程序产品并在控制器上执行该计算机程序产品，以实现第二方面或第三方面所述方法。
可以看到，本发明实施例中，对于LM模式，编码器可以根据当前色度块的采样点位置 来决定当前亮度块采用的亮度下采样滤波器，并通过指示信息(如新增得SPS参数的值)来向解码器指定下采样滤波器的类型。从而保证编码端和解码端都可以得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，保证下采样亮度点的位置与色度采样点位置具有一致性，从而提高编码端的编码准确度和编码效率。
附图说明
为了更清楚地说明本发明实施例或背景技术中的技术方案，下面将对本发明实施例或背景技术中所需要使用的附图进行说明。
图1A示出用于实现本发明实施例的视频译码系统实例的框图；
图1B示出包含图2的编码器20和图3的解码器30中的任一个或两个的视频译码系统实例的框图；
图2示出用于实现本发明实施例的编码器实例结构的框图；
图3示出用于实现本发明实施例的解码器实例结构的框图；
图4示出一种编码装置或解码装置实例的框图；
图5示出另一种编码装置或解码装置实例的框图；
图6示出YUV图像的几种格式的示意图；
图7示出色度采样点位置与亮度采样点位置关系示意图；
图8示出亮度块、下采样后的亮度块以及当前色度块的一种实施例；
图9示出模板亮度点和模板色度点的一种实施例；
图10示出模板亮度点和模板色度点的又一种实施例；
图11示出一些色度采样点位置与亮度采样点的位置关系的示例性图；
图12示出本发明实施例提供的一种色度块预测方法的流程图；
图13示出本发明实施例提供的又一种色度块预测方法的流程图；
图14示出了像素值对集合在亮度-色度坐标系中的分布示意图；
图15示出本发明实施例提供的又一种色度块预测方法的流程图；
图16示出了实现内容分发服务的内容供应系统的示例结构的框图；
图17示出了终端设备的示例的结构的框图。
具体实施方式
下面结合本发明实施例中的附图对本发明实施例进行描述。本发明的实施方式部分使用的术语仅用于对本发明的具体实施例进行解释，而非旨在限定本发明。
视频编码通常是指处理形成视频或视频序列的图片序列。在视频编码领域，术语“图片(picture)”、“帧(frame)”或“图像(image)”可以用作同义词。本文中使用的视频编码表示视频编码或视频解码。视频编码在源侧执行，通常包括处理(例如，通过压缩)原始视频图片以减少表示该视频图片所需的数据量，从而更高效地存储和/或传输。视频解码在目的地侧执行，通常包括相对于编码器作逆处理，以重构视频图片。实施例涉及的视频图片“编码”应理解为涉及视频序列的“编码”或“解码”。编码部分和解码部分的组 合也称为编解码(编码和解码)。
视频序列的多个图片中的每个图片通常分割成不重叠的块集合，通常在块层级上进行编码。换句话说，编码器侧通常在块(也称为图像块，或视频块)层级处理亦即编码视频，例如，通过空间(图片内)预测和时间(图片间)预测来产生预测块，从当前块(当前处理或待处理的块)减去预测块以获取残差块，在变换域变换残差块并量化残差块，以减少待传输(压缩)的数据量，而解码器侧将相对于编码器的逆处理部分应用于经编码或经压缩块，以重构用于表示的当前块。另外，编码器复制解码器处理循环，使得编码器和解码器生成相同的预测(例如帧内预测和帧间预测)和/或重构，用于处理亦即编码后续块。
术语“块”为图片或帧的一部分。本文中，当前块是指当前正在处理的块。例如在编码中，指当前正在编码的块；在解码中，指当前正在解码的块。如果当前处理的块为色度分量块，则称为当前色度块。当前色度块对应的亮度块可以称为当前亮度块。参考块是指为当前块提供参考信号的块，其中，参考信号表示图像块内的像素值或者采样值或者采样信号。预测块是为当前块提供预测信号的块，其中，预测信号表示预测块内的像素值或者采样值或者采样信号。例如，在遍历多个参考块以后，找到了最佳参考块，此最佳参考块将为当前块提供预测，此块称为预测块。
此外，本文中，像素点(或者像素)还可称为采样点，相应的，像素值也可称为采样点的值(或者采样值)。如果当前块所含采样点为亮度采样点，则当前块可称为当前亮度块(或称当前亮度图像块)。如果当前块所含采样点为色度采样点，则当前图像块可称为当前色度块(或称当前色度图像块)。
下面描述本发明实施例所应用的系统架构，参见图1A，图1A为本发明实施例中所描述的一种实例的视频译码系统10的框图。如本文所使用，术语“视频译码器”一般是指视频编码器和视频解码器两者。在本文中，术语“视频译码”或“译码”可一般地指代视频编码或视频解码。如图1A所示，视频译码系统10可包括源设备12和目的地设备14，源设备12产生经编码视频数据，因此，源设备12可被称为视频编码装置。目的地设备14可对由源设备12所产生的经编码的视频数据进行解码，因此，目的地设备14可被称为视频解码装置。源设备12、目的地设备14或两个的各种实施方案可包含一或多个处理器以及耦合到所述一或多个处理器的存储器。所述存储器可包含但不限于RAM、ROM、EEPROM、快闪存储器或可用于以可由计算机存取的指令或数据结构的形式存储所要的程序代码的任何其它媒体，如本文所描述。源设备12和目的地设备14可以包括各种装置，包含桌上型计算机、移动计算装置、笔记型(例如，膝上型)计算机、平板计算机、机顶盒、例如所谓的“智能”电话等电话手持机、电视机、相机、显示装置、数字媒体播放器、视频游戏控制台、车载计算机或其类似者。
源设备12和目的地设备14之间可通过链路13进行通信连接，目的地设备14可经由链路13从源设备12接收经编码视频数据。链路13可包括能够将经编码视频数据从源设备12移动到目的地设备14的一或多个媒体或装置。在一个实例中，链路13可包括使得源设备12能够实时将经编码视频数据直接发射到目的地设备14的一或多个通信媒体。在此实例中，源设备12可根据通信标准(例如无线通信协议)来调制经编码视频数据，且可将经调制的视频数据发射到目的地设备14。所述一或多个通信媒体可包含无线和/或有线通信媒 体，例如射频(RF)频谱或一或多个物理传输线。所述一或多个通信媒体可形成基于分组的网络的一部分，基于分组的网络例如为局域网、广域网或全球网络(例如，因特网)。所述一或多个通信媒体可包含路由器、交换器、基站或促进从源设备12到目的地设备14的通信的其它设备。
源设备12包括编码器20，另外可选地，源设备12还可以包括图片源16、图片预处理器18、以及通信接口22。具体实现形态中，所述编码器20、图片源16、图片预处理器18、以及通信接口22可能是源设备12中的硬件部件，也可能是源设备12中的软件程序。分别描述如下：
图片源16，可以包括或可以为任何类别的图片捕获设备，用于例如捕获现实世界图片，和/或任何类别的图片或评论(对于屏幕内容编码，屏幕上的一些文字也认为是待编码的图片或图像的一部分)生成设备，例如，用于生成计算机动画图片的计算机图形处理器，或用于获取和/或提供现实世界图片、计算机动画图片(例如，屏幕内容、虚拟现实(virtual reality，VR)图片)的任何类别设备，和/或其任何组合(例如，实景(augmented reality，AR)图片)。图片源16可以为用于捕获图片的相机或者用于存储图片的存储器，图片源16还可以包括存储先前捕获或产生的图片和/或获取或接收图片的任何类别的(内部或外部)接口。当图片源16为相机时，图片源16可例如为本地的或集成在源设备中的集成相机；当图片源16为存储器时，图片源16可为本地的或例如集成在源设备中的集成存储器。当所述图片源16包括接口时，接口可例如为从外部视频源接收图片的外部接口，外部视频源例如为外部图片捕获设备，比如相机、外部存储器或外部图片生成设备，外部图片生成设备例如为外部计算机图形处理器、计算机或服务器。接口可以为根据任何专有或标准化接口协议的任何类别的接口，例如有线或无线接口、光接口。
其中，图片可以视为具有亮度值的采样点的二维阵列或矩阵。阵列中的采样点也可以称为像素(pixel)(像素(picture element)的简称)或像素(pel)。阵列或图片在水平和垂直方向(或轴线)上的采样点数目定义图片的尺寸和/或分辨率。为了表示颜色，通常采用三个颜色分量，即图片可以表示为或包含三个采样阵列。RBG格式或颜色空间中，图片包括对应的红色、绿色及蓝色采样阵列。但是，在视频编码中，每个像素通常以亮度/色度格式或颜色空间表示，例如对于YUV格式的图片，包括Y指示的亮度分量(有时也可以用L指示)以及U和V指示的两个色度分量。亮度(简写为luma)分量Y表示亮度或灰度水平强度(例如，在灰度等级图片中两者相同)，而两个色度(简写为chroma)分量U和V表示色度或颜色信息分量。相应地，YUV格式的图片包括亮度采样值(Y)的亮度采样阵列，和色度值(U和V)的两个色度采样阵列。RGB格式的图片可以转换或变换为YUV格式，反之亦然，该过程也称为色彩变换或转换。如果图片是黑白的，该图片可以只包括亮度采样阵列。本发明实施例中，由图片源16传输至图片处理器的图片也可称为原始图片数据17。本发明可能的实施例中，图片源16还可用于来确定当前视频序列的各个图片的色度采样点的位置。
图片预处理器18，用于接收原始图片数据17并对原始图片数据17执行预处理，以获取经预处理的图片19或经预处理的图片数据19。例如，图片预处理器18执行的预处理可以包括整修、色彩格式转换(例如，从RGB格式转换为YUV格式)、调色或去噪。可能实施 例中，图片预处理器18还可能用于确定当前视频序列中的色度采样点的位置。
编码器20(或称编码器20)，用于接收经预处理的图片数据19，采用相关预测模式(如本文各个实施例中的帧内预测模式)对经预处理的图片数据19进行处理，从而提供经编码图片数据21(下文将进一步基于图2或图4或图5描述编码器20的结构细节)。在一些实施例中，编码器20可以用于执行后文所描述的各个实施例，以实现本发明所描述的色度块预测方法在编码侧的应用。
通信接口22，可用于接收经编码图片数据21，并可通过链路13将经编码图片数据21传输至目的地设备14或任何其它设备(如存储器)，以用于存储或直接重构，所述其它设备可为任何用于解码或存储的设备。通信接口22可例如用于将经编码图片数据21封装成合适的格式，例如数据包，以在链路13上传输。
目的地设备14包括解码器30，另外可选地，目的地设备14还可以包括通信接口28、图片后处理器32和显示设备34。分别描述如下：
通信接口28，可用于从源设备12或任何其它源接收经编码图片数据21，所述任何其它源例如为存储设备，存储设备例如为经编码图片数据存储设备。通信接口28可以用于藉由源设备12和目的地设备14之间的链路13或藉由任何类别的网络传输或接收经编码图片数据21，链路13例如为直接有线或无线连接，任何类别的网络例如为有线或无线网络或其任何组合，或任何类别的私网和公网，或其任何组合。通信接口28可以例如用于解封装通信接口22所传输的数据包以获取经编码图片数据21。
通信接口28和通信接口22都可以配置为单向通信接口或者双向通信接口，以及可以用于例如发送和接收消息来建立连接、确认和交换任何其它与通信链路和/或例如经编码图片数据传输的数据传输有关的信息。
解码器30(或称为解码器30)，用于接收经编码图片数据21并提供经解码图片数据31或经解码图片31(下文将进一步基于图3或图4或图5描述解码器30的结构细节)。在一些实施例中，解码器30可以用于执行后文所描述的各个实施例，以实现本发明所描述的色度块预测方法在解码侧的应用。
图片后处理器32，用于对经解码图片数据31(也称为经重构图片数据)执行后处理，以获得经后处理图片数据33。图片后处理器32执行的后处理可以包括：色彩格式转换(例如，从YUV格式转换为RGB格式)、调色、整修或重采样，或任何其它处理，还可用于将将经后处理图片数据33传输至显示设备34。
显示设备34，用于接收经后处理图片数据33以向例如用户或观看者显示图片。显示设备34可以为或可以包括任何类别的用于呈现经重构图片的显示器，例如，集成的或外部的显示器或监视器。例如，显示器可以包括液晶显示器(liquid crystal display，LCD)、有机发光二极管(organic light emitting diode，OLED)显示器、等离子显示器、投影仪、微LED显示器、硅基液晶(liquid crystal on silicon，LCoS)、数字光处理器(digital light processor，DLP)或任何类别的其它显示器。
虽然，图1A将源设备12和目的地设备14绘示为单独的设备，但设备实施例也可以同时包括源设备12和目的地设备14或同时包括两者的功能性，即源设备12或对应的功能性以及目的地设备14或对应的功能性。在此类实施例中，可以使用相同硬件和/或软件，或 使用单独的硬件和/或软件，或其任何组合来实施源设备12或对应的功能性以及目的地设备14或对应的功能性。
本领域技术人员基于描述明显可知，不同单元的功能性或图1A所示的源设备12和/或目的地设备14的功能性的存在和(准确)划分可能根据实际设备和应用有所不同。源设备12和目的地设备14可以包括各种设备中的任一个，包含任何类别的手持或静止设备，例如，笔记本或膝上型计算机、移动电话、智能手机、平板或平板计算机、摄像机、台式计算机、机顶盒、电视机、相机、车载设备、显示设备、数字媒体播放器、视频游戏控制台、视频流式传输设备(例如内容服务服务器或内容分发服务器)、广播接收器设备、广播发射器设备等，并可以不使用或使用任何类别的操作系统。
编码器20和解码器30都可以实施为各种合适电路中的任一个，例如，一个或多个微处理器、数字信号处理器(digital signal processor，DSP)、专用集成电路(application-specific integrated circuit，ASIC)、现场可编程门阵列(field-programmable gate array，FPGA)、离散逻辑、硬件或其任何组合。如果部分地以软件实施所述技术，则设备可将软件的指令存储于合适的非暂时性计算机可读存储介质中，且可使用一或多个处理器以硬件执行指令从而执行本公开的技术。前述内容(包含硬件、软件、硬件与软件的组合等)中的任一者可视为一或多个处理器。
在一些情况下，图1A中所示视频译码系统10仅为示例，本申请的技术可以适用于不必包含编码和解码设备之间的任何数据通信的视频编码设置(例如，视频编码或视频解码)。在其它实例中，数据可从本地存储器检索、在网络上流式传输等。视频编码设备可以对数据进行编码并且将数据存储到存储器，和/或视频解码设备可以从存储器检索数据并且对数据进行解码。在一些实例中，由并不彼此通信而是仅编码数据到存储器和/或从存储器检索数据且解码数据的设备执行编码和解码。
参见图1B，图1B是根据一示例性实施例的包含图2的编码器20和/或图3的解码器30的视频译码系统40的实例的说明图。视频译码系统40可以实现本发明实施例的各种技术的组合。在所说明的实施方式中，视频译码系统40可以包含成像设备41、编码器20、解码器30(和/或藉由处理单元46的逻辑电路47实施的视频编/解码器)、天线42、一个或多个处理器43、一个或多个存储器44和/或显示设备45。
如图1B所示，成像设备41、天线42、处理单元46、逻辑电路47、编码器20、解码器30、处理器43、存储器44和/或显示设备45能够互相通信。如所论述，虽然用编码器20和解码器30绘示视频译码系统40，但在不同实例中，视频译码系统40可以只包含编码器20或只包含解码器30。
在一些实例中，天线42可以用于传输或接收视频数据的经编码比特流。另外，在一些实例中，显示设备45可以用于呈现视频数据。在一些实例中，逻辑电路47可以通过处理单元46实施。处理单元46可以包含专用集成电路(application-specific integrated circuit，ASIC)逻辑、图形处理器、通用处理器等。视频译码系统40也可以包含可选的处理器43，该可选处理器43类似地可以包含专用集成电路(application-specific integrated circuit，ASIC)逻辑、图形处理器、通用处理器等。在一些实例中，逻辑电路47可以通过硬件实施，如视频编码专用硬件等，处理器43可以通过通用软件、操作系 统等实施。另外，存储器44可以是任何类型的存储器，例如易失性存储器(例如，静态随机存取存储器(Static Random Access Memory，SRAM)、动态随机存储器(Dynamic Random Access Memory，DRAM)等)或非易失性存储器(例如，闪存等)等。在非限制性实例中，存储器44可以由超速缓存内存实施。在一些实例中，逻辑电路47可以访问存储器44(例如用于实施图像缓冲器)。在其它实例中，逻辑电路47和/或处理单元46可以包含存储器(例如，缓存等)用于实施图像缓冲器等。
在一些实例中，通过逻辑电路实施的编码器20可以包含(例如，通过处理单元46或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的编码器20，以实施参照图2和/或本文中所描述的任何其它编码器系统或子系统所论述的各种模块。逻辑电路可以用于执行本文所论述的各种操作。
在一些实例中，解码器30可以以类似方式通过逻辑电路47实施，以实施参照图3的解码器30和/或本文中所描述的任何其它解码器系统或子系统所论述的各种模块。在一些实例中，逻辑电路实施的解码器30可以包含(通过处理单元2820或存储器44实施的)图像缓冲器和(例如，通过处理单元46实施的)图形处理单元。图形处理单元可以通信耦合至图像缓冲器。图形处理单元可以包含通过逻辑电路47实施的解码器30，以实施参照图3和/或本文中所描述的任何其它解码器系统或子系统所论述的各种模块。
在一些实例中，的天线42可以用于接收视频数据的经编码比特流。如所论述，经编码比特流可以包含本文所论述的与编码视频帧相关的数据、指示符、索引值、模式选择数据等，例如与编码分割相关的数据(例如，变换系数或经量化变换系数，(如所论述的)可选指示符，和/或定义编码分割的数据)。视频译码系统40还可包含耦合至天线42并用于解码经编码比特流的解码器30。显示设备45用于呈现视频帧。
应理解，本发明实施例中对于参考编码器20所描述的实例，解码器30可以用于执行相反过程。关于信令语法元素，解码器30可以用于接收并解析这种语法元素，相应地解码相关视频数据。在一些例子中，编码器20可以将语法元素熵编码成经编码视频比特流。在此类实例中，解码器30可以解析这种语法元素，并相应地解码相关视频数据。
需要说明的是，本发明实施例描述的色度块预测方法主要用于帧内预测过程，此过程在编码器20和解码器30均存在，本发明实施例中的编码器20和解码器30可以是例如H.263、H.264、HEVV、MPEG-2、MPEG-4、VP8、VP9等视频标准协议或者下一代视频标准协议(如H.266等)对应的编/解码器。
参见图2，图2示出用于实现本发明实施例的编码器20的实例的示意性/概念性框图。在图2的实例中，编码器20包括残差计算单元204、变换处理单元206、量化单元208、逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器单元220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260和熵编码单元270。预测处理单元260可以包含帧间预测单元244、帧内预测单元254和模式选择单元262。帧间预测单元244可以包含运动估计单元和运动补偿单元(未图示)。图2所示的编码器20也可以称为混合型视频编码器或根据混合型视频编解码器的视频编码器。
例如，残差计算单元204、变换处理单元206、量化单元208、预测处理单元260和熵编码单元270形成编码器20的前向信号路径，而例如逆量化单元210、逆变换处理单元212、重构单元214、缓冲器216、环路滤波器220、经解码图片缓冲器(decoded picture buffer，DPB)230、预测处理单元260形成编码器的后向信号路径，其中编码器的后向信号路径对应于解码器的信号路径(参见图3中的解码器30)。
编码器20通过例如输入202，接收图片201或图片201的图像块203，例如，形成视频或视频序列的图片序列中的图片。图像块203也可以称为当前图片块或待编码图片块，图片201可以称为当前图片或待编码图片(尤其是在视频编码中将当前图片与其它图片区分开时，其它图片例如同一视频序列亦即也包括当前图片的视频序列中的先前经编码和/或经解码图片)。
编码器20的实施例可以包括分割单元(图2中未绘示)，用于将图片201分割成多个例如图像块203的块，通常分割成多个不重叠的块。分割单元可以用于对视频序列中所有图片使用相同的块大小以及定义块大小的对应栅格，或用于在图片或子集或图片群组之间更改块大小，并将每个图片分割成对应的块。
在一个实例中，编码器20的预测处理单元260可以用于执行上述分割技术的任何组合。
如图片201，图像块203也是或可以视为具有亮度值(采样值)的采样点的二维阵列或矩阵，虽然其尺寸比图片201小。换句话说，图像块203可以包括，例如，一个采样阵列(例如黑白图片201情况下的亮度阵列)或三个采样阵列(例如，彩色图片情况下的一个亮度阵列和两个色度阵列)或依据所应用的色彩格式的任何其它数目和/或类别的阵列。图像块203的水平和垂直方向(或轴线)上采样点的数目定义图像块203的尺寸。
如图2所示的编码器20用于逐块编码图片201，例如，对每个图像块203执行编码和预测。
残差计算单元204用于基于图片图像块203和预测块265(下文提供预测块265的其它细节)计算残差块205，例如，通过逐样本(逐像素)将图片图像块203的样本值减去预测块265的样本值，以在样本域中获取残差块205。
变换处理单元206用于在残差块205的样本值上应用例如离散余弦变换(discrete cosine transform，DCT)或离散正弦变换(discrete sine transform，DST)的变换，以在变换域中获取变换系数207。变换系数207也可以称为变换残差系数，并在变换域中表示残差块205。
变换处理单元206可以用于应用DCT/DST的整数近似值，例如为HEVC/H.265指定的变换。与正交DCT变换相比，这种整数近似值通常由某一因子按比例缩放。为了维持经正变换和逆变换处理的残差块的范数，应用额外比例缩放因子作为变换过程的一部分。比例缩放因子通常是基于某些约束条件选择的，例如，比例缩放因子是用于移位运算的2的幂、变换系数的位深度、准确性和实施成本之间的权衡等。例如，在解码器30侧通过例如逆变换处理单元212为逆变换(以及在编码器20侧通过例如逆变换处理单元212为对应逆变换)指定具体比例缩放因子，以及相应地，可以在编码器20侧通过变换处理单元206为正变换指定对应比例缩放因子。
量化单元208用于例如通过应用标量量化或向量量化来量化变换系数207，以获取经 量化变换系数209。经量化变换系数209也可以称为经量化残差系数209。量化过程可以减少与部分或全部变换系数207有关的位深度。例如，可在量化期间将n位变换系数向下舍入到m位变换系数，其中n大于m。可通过调整量化参数(quantization parameter，QP)修改量化程度。例如，对于标量量化，可以应用不同的标度来实现较细或较粗的量化。较小量化步长对应较细量化，而较大量化步长对应较粗量化。可以通过量化参数(quantization parameter，QP)指示合适的量化步长。例如，量化参数可以为合适的量化步长的预定义集合的索引。例如，较小的量化参数可以对应精细量化(较小量化步长)，较大量化参数可以对应粗糙量化(较大量化步长)，反之亦然。量化可以包含除以量化步长以及例如通过逆量化210执行的对应的量化或逆量化，或者可以包含乘以量化步长。根据例如HEVC的一些标准的实施例可以使用量化参数来确定量化步长。一般而言，可以基于量化参数使用包含除法的等式的定点近似来计算量化步长。可以引入额外比例缩放因子来进行量化和反量化，以恢复可能由于在用于量化步长和量化参数的等式的定点近似中使用的标度而修改的残差块的范数。在一个实例实施方式中，可以合并逆变换和反量化的标度。或者，可以使用自定义量化表并在例如比特流中将其从编码器通过信号发送到解码器。量化是有损操作，其中量化步长越大，损耗越大。
逆量化单元210用于在经量化系数上应用量化单元208的逆量化，以获取经反量化系数211，例如，基于或使用与量化单元208相同的量化步长，应用量化单元208应用的量化方案的逆量化方案。经反量化系数211也可以称为经反量化残差系数211，对应于变换系数207，虽然由于量化造成的损耗通常与变换系数不相同。
逆变换处理单元212用于应用变换处理单元206应用的变换的逆变换，例如，逆离散余弦变换(discrete cosine transform，DCT)或逆离散正弦变换(discrete sine transform，DST)，以在样本域中获取逆变换块213。逆变换块213也可以称为逆变换经反量化块213或逆变换残差块213。
重构单元214(例如，求和器214)用于将逆变换块213(即经重构残差块213)添加至预测块265，以在样本域中获取经重构块215，例如，将经重构残差块213的样本值与预测块265的样本值相加。
可选地，例如线缓冲器216的缓冲器单元216(或简称“缓冲器”216)用于缓冲或存储经重构块215和对应的样本值，用于例如帧内预测。在其它的实施例中，编码器可以用于使用存储在缓冲器单元216中的未经滤波的经重构块和/或对应的样本值来进行任何类别的估计和/或预测，例如帧内预测。
例如，编码器20的实施例可以经配置以使得缓冲器单元216不只用于存储用于帧内预测254的经重构块215，也用于环路滤波器单元220(在图2中未示出)，和/或，例如使得缓冲器单元216和经解码图片缓冲器单元230形成一个缓冲器。其它实施例可以用于将经滤波块221和/或来自经解码图片缓冲器230的块或样本(图2中均未示出)用作帧内预测254的输入或基础。
环路滤波器单元220(或简称“环路滤波器”220)用于对经重构块215进行滤波以获取经滤波块221，从而顺利进行像素转变或提高视频质量。环路滤波器单元220旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset， SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元220在图2中示出为环内滤波器，但在其它配置中，环路滤波器单元220可实施为环后滤波器。经滤波块221也可以称为经滤波的经重构块221。经解码图片缓冲器230可以在环路滤波器单元220对经重构编码块执行滤波操作之后存储经重构编码块。
编码器20(对应地，环路滤波器单元220)的实施例可以用于输出环路滤波器参数(例如，样本自适应偏移信息)，例如，直接输出或由熵编码单元270或任何其它熵编码单元熵编码后输出，例如使得解码器30可以接收并应用相同的环路滤波器参数用于解码。
经解码图片缓冲器(decoded picture buffer，DPB)230可以为存储参考图片数据供编码器20编码视频数据之用的参考图片存储器。DPB 230可由多种存储器设备中的任一个形成，例如动态随机存储器(dynamic random access memory，DRAM)(包含同步DRAM(synchronous DRAM，SDRAM)、磁阻式RAM(magnetoresistive RAM，MRAM)、电阻式RAM(resistive RAM，RRAM))或其它类型的存储器设备。可以由同一存储器设备或单独的存储器设备提供DPB 230和缓冲器216。在某一实例中，经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经滤波块221。经解码图片缓冲器230可以进一步用于存储同一当前图片或例如先前经重构图片的不同图片的其它先前的经滤波块，例如先前经重构和经滤波块221，以及可以提供完整的先前经重构亦即经解码图片(和对应参考块和样本)和/或部分经重构当前图片(和对应参考块和样本)，例如用于帧间预测。在某一实例中，如果经重构块215无需环内滤波而得以重构，则经解码图片缓冲器(decoded picture buffer，DPB)230用于存储经重构块215。
预测处理单元260，也称为块预测处理单元260，用于接收或获取图像块203(当前图片201的当前图像块203)和经重构图片数据，例如来自缓冲器216的同一(当前)图片的参考样本和/或来自经解码图片缓冲器230的一个或多个先前经解码图片的参考图片数据231，以及用于处理这类数据进行预测，即提供可以为经帧间预测块245或经帧内预测块255的预测块265。
模式选择单元262可以用于选择预测模式(例如帧内或帧间预测模式)和/或对应的用作预测块265的预测块245或255，以计算残差块205和重构经重构块215。
模式选择单元262的实施例可以用于选择预测模式(例如，从预测处理单元260所支持的那些预测模式中选择)，所述预测模式提供最佳匹配或者说最小残差(最小残差意味着传输或存储中更好的压缩)，或提供最小信令开销(最小信令开销意味着传输或存储中更好的压缩)，或同时考虑或平衡以上两者。模式选择单元262可以用于基于码率失真优化(rate distortion optimization，RDO)确定预测模式，即选择提供最小码率失真优化的预测模式，或选择相关码率失真至少满足预测模式选择标准的预测模式。
预测处理单元260可以进一步用于将图像块203分割成较小的块分区或子块，例如，通过迭代使用四叉树(quad-tree，QT)分割、二进制树(binary-tree，BT)分割或三叉树(triple-tree，TT)分割，或其任何组合，以及用于例如为块分区或子块中的每一个执行预测，其中模式选择包括选择分割的图像块203的树结构和选择应用于块分区或子块中的每一个的预测模式。
帧间预测单元244可以包含运动估计(motion estimation，ME)单元(图2中未示出)和运动补偿(motion compensation，MC)单元(图2中未示出)。运动估计单元用于接收或获取图片图像块203(当前图片201的当前图片图像块203)和经解码图片231，或至少一个或多个先前经重构块，例如，一个或多个其它/不同先前经解码图片231的经重构块，来进行运动估计。例如，视频序列可以包括当前图片和先前经解码图片31，或换句话说，当前图片和先前经解码图片31可以是形成视频序列的图片序列的一部分，或者形成该图片序列。
例如，编码器20可以用于从多个其它图片中的同一或不同图片的多个参考块中选择参考块，并向运动估计单元(图2中未示出)提供参考图片和/或提供参考块的位置(X、Y坐标)与当前块的位置之间的偏移(空间偏移)作为帧间预测参数。该偏移也称为运动向量(motion vector，MV)。
运动补偿单元用于获取帧间预测参数，并基于或使用帧间预测参数执行帧间预测来获取帧间预测块245。由运动补偿单元(图2中未示出)执行的运动补偿可以包含基于通过运动估计(可能执行对子像素精确度的内插)确定的运动/块向量取出或生成预测块。内插滤波可从已知像素样本产生额外像素样本，从而潜在地增加可用于编码图片块的候选预测块的数目。一旦接收到用于当前图片块的PU的运动向量，运动补偿单元246可以在一个参考图片列表中定位运动向量指向的预测块。运动补偿单元246还可以生成与块和视频条带相关联的语法元素，以供解码器30在解码视频条带的图片块时使用。
帧内预测单元254用于获取同一图片的图片图像块203(当前图片块)和一个或多个先前经重构块，例如经重构相邻块，以进行帧内估计。例如，编码器20可以用于从多个帧内预测模式中选择一帧内预测模式(如选择LM预测模式)。
例如，对于视频序列的图像的色度分量，在H.265中，图像的色度分量的帧内预测模式可包含5种：Planar模式、垂直模式、水平模式、DC模式，和对应亮度分量模式(DM)。在下一代视频编码标准中(例如H.266)，图像的色度分量的帧内预测模式还包括跨分量预测模式(Cross component prediction，CCP)，跨分量预测模式(Cross component prediction，CCP)又称跨分量帧内预测模式(Cross component intra prediction，CCIP)，或者cross component linear mode(CCLM)预测模式。CCLM预测模式又可简称线性模型模式(linear model mode，简称LM模式)，LM模式这是一种利用亮度和色度之间纹理相关性的色度帧内预测方法。
又例如，对于视频序列的图像的亮度分量，H.265中共有35种亮度分量的帧内预测模式，其中包括33种方向预测模式，DC预测模式，和Planar预测模式。方向预测模式是指将参考像素按照一定的方向(使用intra mode index标记)将参考像素映射到当前块内的像素点位置上得到当前像素点的预测值，或者，对于每一个当前块内的像素点，将其位置按照一定的方向(使用intra mode index标记)反向映射到参考像素上，对应的参考像素的像素值即为当前像素的预测值。不同于方向预测模式，DC预测是将参考像素的均值作为当前块内像素的预测值，而Planar模式则是利用当前像素点的正上方和正左方的参考像素点的像素值以及当前块的右上和左下参考像素点的像素值共同导出当前像素点的预测值。
帧内预测单元254进一步用于基于如所选择的帧内预测模式的帧内预测参数确定帧内预测块255。在任何情况下，在选择用于块的帧内预测模式之后，帧内预测单元254还用于向熵编码单元270提供帧内预测参数，即提供指示所选择的用于块的帧内预测模式的信息。
本发明实施例中，帧内预测单元254还可包括滤波器集合，所述滤波器集合中包括多个滤波器类型，不同的滤波器类型分别表示不同的亮度块下采样算法，各个滤波器类型分别与一种色度点采样位置相对应。帧内预测单元254还可用于确定当前视频序列的色度点的采样位置，基于所述色度点的采样位置确定当前编码所采用的滤波器类型，基于该滤波器类型生成一个指示信息，此指示信息用于指示对当前视频序列编码或解码时(如对图片201或图像块203编码或重建时)，在LM预测模式中对亮度图像下采样过程采用的滤波器类型。帧内预测单元254还用于向熵编码单元270提供滤波器类型的指示信息。
具体的，帧内预测单元254可向熵编码单元270传输语法元素，所述语法元素包括帧内预测参数(比如遍历多个帧内预测模式后选择用于当前块预测的帧内预测模式，例如LM模式，的指示信息)和滤波器类型的指示信息。可能应用场景中，如果帧内预测模式只有一种，即只有LM预测模式，那么也可以不在语法元素中携带帧内预测参数，此时解码端30可直接默认使用LM预测模式进行解码。在一个实例中，帧内预测单元254可以用于执行下文描述的帧内预测技术的任意组合。
熵编码单元270用于将熵编码算法或方案(例如，可变长度编码(variable length coding，VLC)方案、上下文自适应VLC(context adaptive VLC，CAVLC)方案、算术编码方案、上下文自适应二进制算术编码(context adaptive binary arithmetic coding，CABAC)、基于语法的上下文自适应二进制算术编码(syntax-based context-adaptive binary arithmetic coding，SBAC)、概率区间分割熵(probability interval partitioning entropy，PIPE)编码或其它熵编码方法或技术)应用于经量化残差系数209、帧间预测参数、帧内预测参数和/或环路滤波器参数中的单个或所有上(或不应用)，以获取可以通过输出272以例如经编码比特流21的形式输出的经编码图片数据21。可以将经编码比特流传输到解码器30，或将其存档稍后由解码器30传输或检索。熵编码单元270还可用于熵编码正被编码的当前视频条带的其它语法元素。
编码器20的其它结构变型可用于编码视频流。例如，基于非变换的编码器20可以在没有针对某些块或帧的变换处理单元206的情况下直接量化残差信号。在另一实施方式中，编码器20可具有组合成单个单元的量化单元208和逆量化单元210。
具体的，在本发明一实施例中，编码器20可用于：根据所述色度块的采样点位置类型设置滤波器类型的值，根据所述值生成用于指示所述滤波器类型的第一指示信息，所述滤波器类型对应于滤波器集合中的某一个滤波器，然后将所述第一指示信息作为语法元素中的一个信息编入码流，携带于所述经编码过的图像数据21中。
在本发明一实施例中，编码器20还可用于：从多个帧内预测模式中选择LM模式，然后生成第二指示信息，所述第二指示信息用于指示所述线性模式；然后将所述第二指示信息作为语法元素中的一个信息编入码流，携带于所述经编码过的图像数据21中。
在本发明一实施例中，在预测块的构建阶段，编码器20还可用于：在LM模式下，根 据所述第一指示信息，确定所述滤波器类型对应的滤波器集合中的滤波器；然后，根据所述滤波器，对第一亮度块进行下采样，获得第二亮度块，所述第一亮度块是所述当前色度块对应的亮度块；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点下采样获得；然后，根据所述模板色度点和所述模板亮度点，获得线性模型系数；并根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
参见图3，图3示出用于实现本发明实施例的解码器30的实例的示意性/概念性框图。解码器30用于接收例如由编码器20编码的经编码图片数据21，以获取经解码图片231。在解码过程期间，解码器30从编码器20接收视频数据，例如表示经编码视频条带的图片块的经编码视频比特流及相关联的语法元素。
在图3的实例中，解码器30包括熵解码单元304、逆量化单元310、逆变换处理单元312、重构单元314(例如求和器314)、缓冲器316、环路滤波器320、经解码图片缓冲器330以及预测处理单元360。预测处理单元360可以包含帧间预测单元344、帧内预测单元354和模式选择单元362。在一些实例中，解码器30可执行大体上与参照图2的编码器20描述的编码遍次互逆的解码遍次。
熵解码单元304用于对经编码图片数据21执行熵解码，以获取例如经量化系数309和/或经解码的编码参数(图3中未示出)，例如，帧间预测、帧内预测参数、环路滤波器参数和/或其它语法元素中(经解码)的任意一个或全部。熵解码单元304进一步用于将帧间预测参数、帧内预测参数和/或其它语法元素转发至预测处理单元360。解码器30可接收视频条带层级和/或视频块层级的语法元素。
逆量化单元310功能上可与逆量化单元110相同，逆变换处理单元312功能上可与逆变换处理单元212相同，重构单元314功能上可与重构单元214相同，缓冲器316功能上可与缓冲器216相同，环路滤波器320功能上可与环路滤波器220相同，经解码图片缓冲器330功能上可与经解码图片缓冲器230相同。
预测处理单元360可以包括帧间预测单元344和帧内预测单元354，其中帧间预测单元344功能上可以类似于帧间预测单元244，帧内预测单元354功能上可以类似于帧内预测单元254。预测处理单元360通常用于执行块预测和/或从经编码数据21获取预测块365，以及从例如熵解码单元304(显式地或隐式地)接收或获取预测相关参数和/或关于所选择的预测模式的信息。
当视频条带经编码为经帧内编码(I)条带时，预测处理单元360的帧内预测单元354用于基于信号表示的帧内预测模式及来自当前帧或图片的先前经解码块的数据来产生用于当前视频条带的图片块的预测块365。当视频帧经编码为经帧间编码(即B或P)条带时，预测处理单元360的帧间预测单元344(例如，运动补偿单元)用于基于运动向量及从熵解码单元304接收的其它语法元素生成用于当前视频条带的视频块的预测块365。对于帧间预测，可从一个参考图片列表内的一个参考图片中产生预测块。解码器30可基于存储于DPB 330中的参考图片，使用默认建构技术来建构参考帧列表：列表0和列表1。
预测处理单元360用于通过解析运动向量和其它语法元素，确定用于当前视频条带的 视频块的预测信息，并使用预测信息产生用于正经解码的当前视频块的预测块。例如，预测处理单元360使用接收到的一些语法元素确定用于编码视频条带的视频块的预测模式(例如，帧内或帧间预测)、帧间预测条带类型(例如，B条带、P条带或GPB条带)、用于条带的参考图片列表中的一个或多个的建构信息、用于条带的每个经帧间编码视频块的运动向量、条带的每个经帧间编码视频块的帧间预测状态以及其它信息，以解码当前视频条带的视频块。
逆量化单元310可用于逆量化(即，反量化)在比特流中提供且由熵解码单元304解码的经量化变换系数。逆量化过程可包含使用由编码器20针对视频条带中的每一视频块所计算的量化参数来确定应该应用的量化程度并同样确定应该应用的逆量化程度。
逆变换处理单元312用于将逆变换(例如，逆DCT、逆整数变换或概念上类似的逆变换过程)应用于变换系数，以便在像素域中产生残差块。
重构单元314(例如，求和器314)用于将逆变换块313(即经重构残差块313)添加到预测块365，以在样本域中获取经重构块315，例如通过将经重构残差块313的样本值与预测块365的样本值相加。
环路滤波器单元320(在编码循环期间或在编码循环之后)用于对经重构块315进行滤波以获取经滤波块321，从而顺利进行像素转变或提高视频质量。在一个实例中，环路滤波器单元320可以用于执行下文描述的滤波技术的任意组合。环路滤波器单元320旨在表示一个或多个环路滤波器，例如去块滤波器、样本自适应偏移(sample-adaptive offset，SAO)滤波器或其它滤波器，例如双边滤波器、自适应环路滤波器(adaptive loop filter，ALF)，或锐化或平滑滤波器，或协同滤波器。尽管环路滤波器单元320在图3中示出为环内滤波器，但在其它配置中，环路滤波器单元320可实施为环后滤波器。
随后将给定帧或图片中的经解码视频块321存储在存储用于后续运动补偿的参考图片的经解码图片缓冲器330中。
解码器30用于例如，藉由输出332输出经解码图片31，以向用户呈现或供用户查看。
解码器30的其它变型可用于对压缩的比特流进行解码。例如，解码器30可以在没有环路滤波器单元320的情况下生成输出视频流。例如，基于非变换的解码器30可以在没有针对某些块或帧的逆变换处理单元312的情况下直接逆量化残差信号。在另一实施方式中，解码器30可以具有组合成单个单元的逆量化单元310和逆变换处理单元312。
具体的，在本发明一实施例中，解码器30用于：解析码流获得第一指示信息和第二指示信息，所述第二指示信息用于指示当前解码色度块采用的帧内预测模式为LM模式，所述第一指示信息用于指示滤波器类型；根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点下采样获得；然后，根据所述模板色度点和所述模板亮度点，获得线性模型系数；然后，根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
参见图4，图4是本发明实施例提供的视频译码设备400(例如视频编码设备400或视 频解码设备400)的结构示意图。视频译码设备400适于实施本文所描述的实施例。在一个实施例中，视频译码设备400可以是视频解码器(例如图1A的解码器30)或视频编码器(例如图1A的编码器20)。在另一个实施例中，视频译码设备400可以是上述图1A的解码器30或图1A的编码器20中的一个或多个组件。
视频译码设备400包括：用于接收数据的入口端口410和接收单元(Rx)420，用于处理数据的处理器、逻辑单元或中央处理器(CPU)430，用于传输数据的发射器单元(Tx)440和出口端口450，以及，用于存储数据的存储器460。视频译码设备400还可以包括与入口端口410、接收器单元420、发射器单元440和出口端口450耦合的光电转换组件和电光(EO)组件，用于光信号或电信号的出口或入口。
处理器430通过硬件和软件实现。处理器430可以实现为一个或多个CPU芯片、核(例如，多核处理器)、FPGA、ASIC和DSP。处理器430与入口端口410、接收器单元420、发射器单元440、出口端口450和存储器460通信。处理器430包括译码模块470(例如编码模块470或解码模块470)。编码/解码模块470实现本文中所公开的实施例，以实现本发明实施例所提供的色度块预测方法。例如，编码/解码模块470实现、处理或提供各种编码操作。因此，通过编码/解码模块470为视频译码设备400的功能提供了实质性的改进，并影响了视频译码设备400到不同状态的转换。或者，以存储在存储器460中并由处理器430执行的指令来实现编码/解码模块470。
存储器460包括一个或多个磁盘、磁带机和固态硬盘，可以用作溢出数据存储设备，用于在选择性地执行这些程序时存储程序，并存储在程序执行过程中读取的指令和数据。存储器460可以是易失性和/或非易失性的，可以是只读存储器(ROM)、随机存取存储器(RAM)、随机存取存储器(ternary content-addressable memory，TCAM)和/或静态随机存取存储器(SRAM)。
参见图5，图5是根据一示例性实施例的可用作图1A中的源设备12和目的地设备14中的任一个或两个的装置500的简化框图。装置500可以实现本申请的技术，用于实现色度块预测的装置500可以采用包含多个计算设备的计算系统的形式，或采用例如移动电话、平板计算机、膝上型计算机、笔记本电脑、台式计算机等单个计算设备的形式。
装置500中的处理器502可以为中央处理器。或者，处理器502可以为现有的或今后将研发出的能够操控或处理信息的任何其它类型的设备或多个设备。如图所示，虽然可以使用例如处理器502的单个处理器实践所揭示的实施方式，但是使用一个以上处理器可以实现速度和效率方面的优势。
在一实施方式中，装置500中的存储器504可以为只读存储器(Read Only Memory，ROM)设备或随机存取存储器(random access memory，RAM)设备。任何其他合适类型的存储设备都可以用作存储器504。存储器504可以包括代码和由处理器502使用总线512访问的数据506。存储器504可进一步包括操作系统508和应用程序510，应用程序510包含至少一个准许处理器502执行本文所描述的方法的程序。例如，应用程序510可以包括应用1到N，应用1到N进一步包括执行本文所描述的方法的视频编码应用。装置500还可包含采用从存储器514形式的附加存储器，该从存储器514例如可以为与移动计算设备 一起使用的存储卡。因为视频通信会话可能含有大量信息，这些信息可以整体或部分存储在从存储器514中，并按需要加载到存储器504用于处理。
装置500还可包含一或多个输出设备，例如显示器518。在一个实例中，显示器518可以为将显示器和可操作以感测触摸输入的触敏元件组合的触敏显示器。显示器518可以通过总线512耦合于处理器502。除了显示器518还可以提供其它准许用户对装置500编程或以其它方式使用装置500的输出设备，或提供其它输出设备作为显示器518的替代方案。当输出设备是显示器或包含显示器时，显示器可以以不同方式实现，包含通过液晶显示器(liquid crystal display，LCD)、阴极射线管(cathode-ray tube，CRT)显示器、等离子显示器或发光二极管(light emitting diode，LED)显示器，如有机LED(organic LED，OLED)显示器。
装置500还可包含图像感测设备520或与其连通，图像感测设备520例如为相机或为现有的或今后将研发出的可以感测图像的任何其它图像感测设备520，所述图像例如为运行装置500的用户的图像。图像感测设备520可以放置为直接面向运行装置500的用户。在一实例中，可以配置图像感测设备520的位置和光轴以使其视野包含紧邻显示器518的区域且从该区域可见显示器518。
装置500还可包含声音感测设备522或与其连通，声音感测设备522例如为麦克风或为现有的或今后将研发出的可以感测装置500附近的声音的任何其它声音感测设备。声音感测设备522可以放置为直接面向运行装置500的用户，并可以用于接收用户在运行装置500时发出的声音，例如语音或其它发声。
虽然图5中将装置500的处理器502和存储器504绘示为集成在单个单元中，但是还可以使用其它配置。处理器502的运行可以分布在多个可直接耦合的机器中(每个机器具有一个或多个处理器)，或分布在本地区域或其它网络中。存储器504可以分布在多个机器中，例如基于网络的存储器或多个运行装置500的机器中的存储器。虽然此处只绘示单个总线，但装置500的总线512可以由多个总线形成。进一步地，从存储器514可以直接耦合至装置500的其它组件或可以通过网络访问，并且可包括单个集成单元，例如一个存储卡，或多个单元，例如多个存储卡。因此，可以以多种配置实施装置500。
为了更好理解本发明实施例的技术方案，下面进一步描述本发明实施例涉及的YUV图像(或称YCbCr图像)和色度分量帧内预测的LM模式。
现有的视频一般为彩色视频，彩色视频中图像除了含有亮度分量(Y)以外，还含有色度分量(U，V)，因此这样的图像又可称为YUV图像。因此，对YUV图像编码时，除了对亮度分量进行编码，还需要对色度分量进行编码。研究表明人眼对亮度比较敏感，而对色彩不怎么敏感。所以，在编码中，为了节省存储空间，提高编码效率，亮度分量全分辨率进行采样，而色度分量可不用全分辨率采样。按照彩色视频中亮度分量和色度分量的采样方法的不同，一般视频序列的图像有4:4:4格式的YUV图像，4:2:2格式的YUV图像，4:2:0格式的YUV图像,等等。参见图6，图6示例性的示出了4:4:4格式、4:2:2格式和4:2:0格式，其中，图示中的叉(×)表示亮度分量采样点，图示中的圈(〇)表示色度分量采样点。
其中，4:4:4格式表示色度分量没有下采样，4:4:4格式是色度分量分辨率最高的格式，也就是说，相邻4个像素点里的数据有4个Y、4个U、4个V。
4:2:2格式表示色度分量相对于亮度分量进行2:1的水平下采样，没有竖直下采样。对于每两个U采样点或V采样点，每行都包含四个Y采样点。也就是说，相邻的4个像素点里的数据有4个Y、2个U、2个V。
4:2:0格式表示色度分量相对于亮度分量进行2:1的水平下采样，以及2:1的竖直下采样。4:2:0格式是色度分量分辨率最低的格式，也是最为常见的格式。4:2:0格式中，色度采样在每行中(即水平方向)只有亮度采样的一半，在每列中(即竖直方向)只有亮度采样的一半。在视频图像采用4:2:0格式的情况下，若图像块的亮度分量为2Mx2N大小的图像块，则图像块的色度分量为MxN大小的图像块。举例来说，如果图像块的分辨率是720*480，那么图像块的亮度分量的分辨率是720*480，图像块的色度分量的分辨率是360*240。
对于4:2:0格式，根据色度点的采样位置的不同，可存在6种不同的色度采样点位置类型。参见图7，图7示例性地示出了亮度点的亮度采样点位置与色度点的6种不同色度采样点位置之间的相互关系，这6种不同的色度采样点位置类型分别为类型0(type 0)、类型1(type 1)、类型2(type 2)、类型3(type 3)、类型4(type4)和类型5(type 5)。
本文将以4:2:0格式的YUV图像为例介绍本发明实施例的技术方案。本文中，当前待处理图像块的亮度分量也可称为亮度块(或称当前色度块对应亮度块，或称第一亮度块，或称亮度分量块，或称luma块)，当前待处理图像块的色度分量也可称为当前色度块(或称为色度块，或称为色度分量块，或称chroma块)。
对于色度分量帧内预测，与亮度分量类似，色度分量帧内预测是利用当前色度块周围相邻已重建块的边界像素作为当前色度块的参考像素，按照一定的预测模式将参考像素映射到当前色度块内的像素点，作为当前色度块内像素的预测值。所不同的是，由于色度分量的纹理一般较为简单，所以色度分量帧内预测模式的数量一般少于亮度分量预测模式的数量。例如，在H.265中，色度分量的帧内预测模式仅包含5种，即Planar模式、垂直模式、水平模式、DC模式、和对应亮度分量模式(DM)。在下一代视频编码标准(如H.266)中，色度分量帧内预测模式还包括有跨分量预测(Cross component prediction，CCP)模式。
需要理解的是，在不同的应用场景中，CCP模式又可可能被称为跨分量帧内预测模式(Cross component intra prediction，CCIP)，或者跨分量线性预测模式(cross component linear mode，CCLM))，或者简称为线性模型模式(linear model mode，即LM模式)。本文中以LM模式为例进行相关描述。
LM模式是一种利用亮度和色度之间纹理相关性的色度帧内预测方法。它使用重建亮度分量按照线性模型导出当前色度块预测值，从而为色度分量提供更加准确的预测值。LM模式可以表示为下式：
pred C(i,j)＝α*rec L′(i,j)+β
其中，α，β为线性模型系数，pred C(i,j)为(i,j)位置上的色度像素的预测值；rec L′(i,j)为当前色度块对应亮度块下采样至色度分量分辨率后，(i,j)位置上的亮度重 建像素值。对于4:2:0格式的视频序列，亮度分量的分辨率是色度分量的分辨率的4倍，为了得到与色度块同分辨率的亮度块，需要将亮度分量按照色度分量相同的下采样方法下采样至色度分量的分辨率，再进行使用。
以图8为例，图8分别示出了一种4:2:0格式的YUV图像中，当前色度块对应的亮度块(即图像块的亮度分量)以及其相邻上边和左边的参考像素点、下采样后的亮度块(即图像块下采样后的亮度分量，或称第二亮度块)以及其相邻上边和左边的已重建参考像素点、当前色度块(即图像块的色度分量)以及其相邻上边和左边的已重建参考像素点。当前色度块对应的亮度块的分辨率为2W*2H，下采样后的亮度块的分辨率为W*H，当前色度块的分辨率为W*H。也就是说，将亮度块以及亮度块的相邻参考像素点进行下采样至色度分量的分辨率，即可得到下采样后的亮度块。下采样后的亮度块的相邻参考像素点和当前色度块的相邻参考像素点构成一一对应关系。
参见图9和图10，本发明实施例中，为了便于理解，可将用于计算线性模型系数的相邻上边和左边称为模板(template)。模板表示用于计算线性模型系数的亮度点或色度点的集合，其中，用于计算线性模型系数的亮度点(luma sample)的集合又可称为模板亮度点，所述模板亮度点通过对亮度块相邻的多个亮度像素点进行下采样操作而获得(因为亮度图像中，与模板色度点相匹配的位置可能并没有亮度采样值)。用于计算线性模型系数的色度点(chroma sample)的集合又可称为模板色度点，所述模板色度点包括所述当前色度块相邻的多个已重建色度像素点。
在一可能实施例中，所述模板色度点具体包括所述当前色度块相邻上边一行或者上边多行的色度像素点，以及，所述当前色度块相邻左边一列或者左边多列的色度像素点。模板亮度点以及模板色度点一一对应，并且采样点的值构成值对。
例如，在图9中，模板色度点为当前色度块相邻上边一行色度像素点，以及一列色度像素点。相应的，模板亮度点包括与模板色度点中的各个色度点位置相匹配的一行亮度像素点，以及左边一列亮度像素点。
例如，如图10所示，在一实例中，模板色度点为当前色度块相邻上边两行色度像素点，以及左边两列色度像素点。相应的，模板亮度点包括与模板色度点中的各个色度点位置相匹配的两行亮度像素点，以及两列亮度像素点。
当然，模板色度点和模板亮度点的具体实现方式还可以是多种多样的，在又一实例中，所述模板色度点也可只包括所述当前色度块相邻左边一列或者左边多列的色度像素点。模板亮度点以及模板色度点一一对应，只包括位置匹配的一列或者多列的亮度像素点。在又一实例中，所述模板色度点也可只包括所述当前色度块相邻上边一行或者上边多行的色度像素点。模板亮度点以及模板色度点一一对应，只包括位置匹配的一行或者多行的亮度像素点。
如上所述，模板亮度点为通过对亮度块相邻的多个亮度像素点进行下采样操作(downsampling)而获得，下面示例性地描述模板亮度点的进行下采样操作的方法。
参见图11，图11为一些色度采样点位置与亮度采样点的位置关系的示例性图。对于4:2:0格式的YUV图像，如果以亮度图像的左上角顶点为亮度采样点坐标原点，色度图像的左上角顶点为色度采样点坐标原点，则色度图像中(xb,yb)采样点位置对应到亮度图像中 的位置为(2*xb,2*yb+0.5)。为了得到模板亮度点中的亮度像素点的值，即(xb,yb)采样点位置对应的亮度像素值，则可先选取亮度块相邻的多个亮度像素点，例如所述亮度块相邻的多个亮度像素点的采样点位置分别为(2*xb,2*yb)、(2*xb-1,2*yb)、(2*xb+1,2*yb)、(2*xb,2*yb+1)、(2*xb-1,2*yb+1)、(2*xb+1,2*yb+1)，则根据这些位置分别对应在亮度图像中的亮度像素值来导出(2*xb,2*yb+0.5)位置上的值，将该值作为(xb,yb)采样点位置对应的亮度像素值。
例如，在一实例中，可按照下式对多个亮度像素点进行下采样计算，得到模板亮度点中，(xb,yb)采样点位置对应的亮度点的值LC(xb,yb)：
LC(xb,yb)＝(2*L(2*xb,2*yb)+L(2*xb-1,2*yb)+L(2*xb+1,2*yb)+2*L(2*xb,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb+1,2*yb+1)+4)>>3
其中，符号“>>”表示右移。
可以理解的，对于当前块的模板亮度点中的其他亮度点(xb+1,yb-1)…(xb+i,yb-1)…，以及(xb-1,yb)，…(xb-1,yb+j)的值，也可采用上述相同的下采样方法进行下采样。
需要说明的是，现有的采样方法为基于固定的滤波器进行下采样。也就是说，对于各种视频序列中的图像，现有的LM模式中，无论色度采样点的位置如何，均使用一种固定的下采样滤波器，而并没有考虑实际中不同的视频序列可能存在的不同的色度采样点位置，以及色度采样点位置的不同对亮度下采样滤波器的影响，如果对亮度下采样滤波器采样点的位置与色度采样点的位置不一致，将会导致通过LM模型公式导出的LM模型系数α和β不准确，也会造成rec L′(i,j)与色度点位置不对齐，进而影响编码效率。
为了解决上述缺陷，提高在LM模式下对色度块进行预测的准确性，以及提高编码效率，本发明实施例基于上文所描述的系统及设备，提出了一种用于LM模式的色度块预测方法，首先从编码端的角度进行描述，参见图12，该方法包括但不限于以下步骤：
步骤701：确定对当前色度块进行预测时采用的帧内预测模式为LM模式。
在一具体实现中，编码端在帧内预测中可只预设LM模式，即在这种情况下编码端直接确定当前采用的帧内预测模式为LM模式，后续继续执行如步骤702-步骤704。
在又一具体实现中，在编码端的帧内预测中，也可预设多种帧内预测模式，所述多种帧内预测模式中包括LM模式，编码端遍历所述多种帧内预测模式，确定对当前色度块的预测中最优的帧内预测模式为LM模式，在这种情况下，启动执行后续步骤如步骤702-步骤704。
此外，编码端还可设置第二指示信息，所述第二指示信息用于指示所述LM模式，以便于在后续步骤704中将第二指示信息编入码流。
步骤702：根据当前色度块的采样点位置类型确定滤波器类型。
也就是说，本发明实施例的设计中，基于LM模式对当前色度块进行预测时，所采用的亮度下采样滤波器并不是固定设置的，而是由当前色度块的采样点位置类型来决定的。每一种当前色度块的采样点位置类型皆有对应的滤波器类型。
在本发明的一种具体实施例中，可设计6种采样点位置类型(可将该设计称为设计一)， 如图7所示，这6种采样点位置类型包括：type0、type1、type2、type3、type4和type5。那么，对应于所述6种采样点位置类型，分别有6种类型的亮度下采样滤波器，可分别称为：滤波器0、滤波器1、滤波器2、滤波器3、滤波器4、滤波器5。在一实例中，这些滤波器的下采样算法可分别设置如下：
对于滤波器0：
LC(xb,yb)＝(2*L(2*xb,2*yb)+L(2*xb-1,2*yb)+L(2*xb+1,2*yb)+2*L(2*xb,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb+1,2*yb+1)+4)>>3.
对于滤波器1：
LC(xb,yb)＝(L(2*xb,2*yb)+L(2*xb+1,2*yb)+L(2*xb,2*yb+1)+L(2*xb+1,2*yb+1)+2)>>2.
对于滤波器2：
LC(xb,yb)＝(4*L(2*xb,2*yb)
+2*L(2*xb,2*yb+1)+2*L(2*xb,2*yb-1)+2*L(2*xb-1,2*yb)+2*L(2*xb+1,2*yb)
+L(2*xb+1,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb-1,2*yb-1)+L(2*xb+1,2*yb-1)+8)>>4.
对于滤波器3：
LC(xb,yb)＝(2*L(2*xb,2*yb)+2*L(2*xb+1,2*yb)+L(2*xb,2*yb-1)+L(2*xb+1,2*yb-1)+L(2*xb,2*yb+1)+L(2*xb+1,2*yb+1)+4)>>3.
对于滤波器4：
LC(xb,yb)＝(4*L(2*xb,2*yb+1)
+2*L(2*xb,2*yb+2)+2*L(2*xb,2*yb)+2*L(2*xb-1,2*yb+1)+2*L(2*xb+1,2*yb+1)
+L(2*xb+1,2*yb+2)+L(2*xb-1,2*yb+2)+L(2*xb-1,2*yb)+L(2*xb+1,2*yb)+8)>>4.
对于滤波器5：
LC(xb,yb)＝(2*L(2*xb,2*yb+1)+2*L(2*xb+1,2*yb+1)+L(2*xb,2*yb)+L(2*xb+1,2*yb)+L(2*xb,2*yb+2)+L(2*xb+1,2*yb+2)+4)>>3.
需要说明的是，上述各个滤波器的下采样算法仅仅作为示例而非限定。
在本发明的又一种具体实施例中，考虑到目前type0以及type2的色度点采样位置最为常见，也可设计2种采样点位置类型(可将该设计称为设计二)，即这2种采样点位置类型只包括：type0、type2。那么，对应于所述2种采样点位置类型，分别有2种类型亮度下采样滤波器，可分别称为：滤波器0、滤波器2。在一实例中，这些滤波器的下采样算法可分别设置如下：
对于滤波器0：
LC(xb,yb)＝(2*L(2*xb,2*yb)+L(2*xb-1,2*yb)+L(2*xb+1,2*yb)+2*L(2*xb,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb+1,2*yb+1)+4)>>3.
对于滤波器2：
LC(xb,yb)＝(4*L(2*xb,2*yb)
+2*L(2*xb,2*yb+1)+2*L(2*xb,2*yb-1)+2*L(2*xb-1,2*yb)+2*L(2*xb+1,2*yb)
+L(2*xb+1,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb-1,2*yb-1)+L(2*xb+1,2*yb-1)+8)>>4.
需要说明的是，上述各个滤波器的下采样算法仅仅作为示例而非限定。
还需要说明的是，除了上述两种设计外，本发明实施例还可以是其他的设计，例如设计3种色度点采样位置，以及3种色度点采样位置分别对应的3种类型的滤波器，等等，这里不做限定。
这样，编码端可首先确定当前色度块的采样点位置类型，进而根据当前色度块的采样点位置类型来确定对应的滤波器类型，亦即，确定LM模式对当前色度块进行预测时所采用的亮度下采样滤波器。
步骤703：设置第一指示信息，所述第一指示信息用于指示所述滤波器类型。
本发明实施例新增一个序列参数集(sequence parameter set，SPS)参数，此SPS参数的值将用于指示当前视频序列编码或者解码时，LM模式中的亮度下采样滤波器的类型。在编码端，此参数可以基于当前序列的色度点的采样位置设置。具体的，可根据滤波器类型设置第一指示信息，所述第一指示信息即包括该SPS参数的值，用于指示编码或者解码时对色度块预测中所采用的亮度下采样滤波器的类型。
在本发明一具体实现中，可将该新增的SPS参数语法元素名称为：“lm_mode_downsampling_filter_type_idc”，lm_mode_downsampling_filter_type_idc用来指定LM模式的下采样滤波器类型。
举例来说，对于步骤702描述的设计一，设计6种滤波器类型：滤波器0、滤波器1、滤波器2、滤波器3、滤波器4、滤波器5，这种情况下，序列参数集可设计如下：
Figure PCTCN2019104527-appb-000001
其中，lm_mode_downsampling_filter_type_idc的值在0到5的范围内。不同的值对应不同的滤波器，比如：值0对应滤波器0、值1对应滤波器1、值2对应滤波器2、值3对应滤波器3、值4对应滤波器4、值5对应滤波器5，等等。当然，上述各个值的设定以及各个值与滤波器的对应关系仅仅作为示例而非限定。
又举例来说，对于步骤702描述的设计二，设计2种滤波器类型：滤波器0、滤波器2、，这种情况下，序列参数集可设计如下：
Figure PCTCN2019104527-appb-000002
其中，lm_mode_downsampling_filter_type_idc的值可为0或1，不同的值对应不同的滤波器，比如：值0对应滤波器0、值1对应滤波器2，等等。当然，上述各个值的设定以及各个值与滤波器的对应关系仅仅作为示例而非限定。
步骤704：将所述第一指示信息编入码流，发送码流至解码端。具体实现中，还可将上述步骤701中设置的第二指示信息编入所述码流进而发送至解码端，所述第二指示信息用于指示LM模式，以便于指示解码端采用LM模式。
需要说明的是，上述实施例仅仅描述了编码端实现编码和码流发送的过程，根据前文的描述，本领域技术人员理解编码端还可以在其他环节实施本发明实施例所描述的其他方法。例如在编码端在色度块预测中，对色度块的重构过程的具体实现可参考后文在解码端描述的相关方法，在这里不再赘述。
可以看到，本发明实施例中，对于LM模式，编码器可以根据当前色度点的采样位置类型来决定当前亮度块采用的亮度下采样滤波器，并通过指示信息(如新增得SPS参数的值)来向解码器指定下采样滤波器的类型。从而保证编码端和解码端都可以得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，保证下采样亮度点的位置与色度采样点位置具有一致性，从而提高编码端的编码准确度和编码效率。
基于上文所描述的系统及设备，本发明实施例提供了又一种色度块预测方法，从解码端的角度进行描述，参见图13，该方法包括但不限于以下步骤：
步骤801：解析码流获得第一指示信息。
具体的，解码端可通过解析码流中的序列参数集(SPS)参数获得所述第一指示信息。例如，码流中的SPS参数具体可以是新增一种的SPS参数。
在一种实施例中，第一指示信息用于指示滤波器类型。
具体的，解码端解析编码端传输的码流，获得用于指示滤波器类型的第一指示信息。所述第一指示信息的详细内容可参考图12实施例步骤703的描述。
编码端和解码端可对滤波器类型进行相同的设计。例如，编码端设计有6种滤波器类型(对应于6种色度采样点位置)，解码端也设计有6种滤波器类型，且所述解码端的6种滤波器类型的下采样算法分别与编码端一致，分别为：滤波器0、滤波器1、滤波器2、滤波器3、滤波器4、滤波器5。那么解码端收到的第一指示信息用于指示6种滤波器类型中的某一个。比如，第一指示信息为SPS参数lm_mode_downsampling_filter_type_idc，该SPS参数取值为2时，即说明第一指示信息指示滤波器类型为滤波器2。
又例如，编码端设计有2种滤波器类型(对应于2种色度采样点位置)，解码端也设计 有2种滤波器类型，且所述解码端的2种滤波器类型的下采样算法分别与编码端一致，分别为：滤波器0、滤波器2。那么解码端收到的第一指示信息用于指示2种滤波器类型中的某一个。比如，第一指示信息为SPS参数lm_mode_downsampling_filter_type_idc，该SPS参数取值为0时，即说明第一指示信息指示滤波器类型为滤波器0。
在又一种实施例中，第一指示信息用于指示当前色度块的采样点位置，当前色度块的采样点位置关联所述滤波器类型。所以，解码端可根据当前色度块的采样点位置确定滤波器类型。
进一步地，第一指示信息可具体用于指示当前色度块的采样点位置类型，相应的，当前色度块的采样点位置类型关联所述滤波器类型。所以，解码端可根据当前色度块的采样点位置类型确定滤波器类型。
例如，编码端设计有2种滤波器类型(对应于2种色度采样点位置)，解码端也设计有2种滤波器类型，且所述解码端的2种滤波器类型的下采样算法分别与编码端一致，分别为：滤波器0、滤波器2。那么解码端收到的第一指示信息用于指示2种色度采样点位置中的某一个。比如，第一指示信息为SPS参数lm_mode_downsampling_filter_type_idc，该SPS参数取值为0时，指示了第一种色度采样点位置，例如为type0。由于采样点位置类型和滤波器类型相关联，解码端可直接根据第一种采样点位置类型type0，确定滤波器类型为滤波器0。又比如，该SPS参数取值为1时，指示了第二种色度采样点位置，例如为type2，由于采样点位置类型和滤波器类型相关联，解码端可直接根据第二种采样点位置类型type2，确定滤波器类型为滤波器2。
此外，具体实施例中，在解析码流的环节中，还可通过解析所述码流获得第二指示信息，所述第二指示信息用于指示解码端解码当前色度块采用的帧内预测模式为LM模式，从而解码端确定对视频序列的当前图像的帧内预测采用LM模式，进而，后续执行相关步骤802-805。
步骤802：根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作(downsampling)，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块。
具体实施例中，可使用第一指示信息对应的滤波器对当前图像的当前色度块亮度块(即第一亮度块)进行下采样，得到下采样后的亮度块(即第二亮度块)中的各个亮度像素点的值，从而得到了LM模式的算法公式中的rec L′(i,j)。
举例来说，解码端设计有6种滤波器类型，且当前第一指示信息指示的值为0，则采用的亮度下采样滤波器为滤波器0，采样算法如下：
LC(xb,yb)＝(2*L(2*xb,2*yb)+L(2*xb-1,2*yb)+L(2*xb+1,2*yb)+2*L(2*xb,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb+1,2*yb+1)+4)>>3
所以，利用该滤波器0对第一亮度块进行下采样即可得到第二亮度块中的各个亮度像素点的值。
又举例来说，解码端设计有2种滤波器类型(如滤波器0和滤波器2)，且当前第一指示信息指示的值为1，则采用的亮度下采样滤波器为滤波器2，采样算法如下：
LC(xb,yb)＝(4*L(2*xb,2*yb)
+2*L(2*xb,2*yb+1)+2*L(2*xb,2*yb-1)+2*L(2*xb-1,2*yb)+2*L(2*xb+1,2*yb)
+L(2*xb+1,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb-1,2*yb-1)+L(2*xb+1,2*yb-1)+8)>>4
所以，利用该滤波器2对第一亮度块进行下采样即可得到第二亮度块中的各个亮度像素点的值。
步骤803：获取模板色度点和模板亮度点。其中，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得。步骤803的具体实现可参考上文图9和图10实施例的相关描述，为了说明书的简洁，这里不再赘述。
需要说明的是，步骤802和步骤803之间并无必然的先后顺序，即步骤802可在步骤803之前或之后执行，步骤802和步骤803也可能会同时执行。
步骤804：根据所述模板色度点和所述模板亮度点，获得线性模型系数α和β。
举例来说，在一种实现方式中，可利用最小二乘法的方法来求取线性模型系数α和β。具体的，例如可使用如图9中所示的下采样后的亮度块的模板色度点和图9中所示的模板色度点构建线性方程组。记模板色度点或模板亮度点中的相邻参考像素的个数为N，使用L(n)、C(n)来分别表示其中第n个亮度像素点的值和色度像素点的值，则线线性模型系数α和β分别为：
Figure PCTCN2019104527-appb-000003
Figure PCTCN2019104527-appb-000004
又举例来说，在又一种实现方式中，可利用极值的方法来求取线性模型系数α和β。具体的，记模板色度点或模板亮度点中的相邻参考像素的个数为N，使用L(n)、C(n)分别表示其中第n个亮度像素点的值和色度像素点的值,L(n)和C(n)构成像素值对，则可得像素值对集合为：{(L 0,C 0),(L 1,C 1),(L 2,C 2)…(L n,C n)…(L N-1,C N-1)},这里N为用于确定线性模型系数的当前色度块相邻像素点的个数。如图14所示，图14示出了像素值对集合在亮度-色度坐标系中的分布。在上述像素值对集合中找到最大亮度值L max以及最小亮度值L min对应的值对，设第i个像素点B对应最大亮度值点，即L i＝L max,设第j个像素点A对应最小亮度值点，即L j＝L min，则线线性模型系数α和β分别为：
Figure PCTCN2019104527-appb-000005
β＝C j-α*L j
需要理解的是，上述例子仅仅作为示例而非限定，在得到模板色度点的各个亮度像素点的值和模板亮度点的各个色度像素点的值后，本发明实施例并不限定于采用任何方式来基于模板色度点和模板亮度点导出LM模式的线性模型系数α和β。
步骤805：根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。可以理解的，在得到rec L′(i,j)和线性模型系数α和β后，根据LM模式的算法公式：
pred C(i,j)＝α*rec L′(i,j)+β
即可得到获得当前色度块中各个色度像素点的预测值pred C(i,j)。
可以看到，本发明实施例中，对于LM模式，解码端在对当前色度块对应的亮度块的下采样过程中，可通过码流中的指示信息(如新增的SPS参数的值)来确定LM模式中当前色度块对应的亮度块下采样时采用的滤波器。从而可以得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，保证下采样亮度点的位置与色度采样点位置具有一致性。
基于上文所描述的系统及设备，本发明实施例提供了又一种色度块预测方法，从解码端的角度进行描述，参见图15，图15实施例与上述图13实施例的区别在于，图15实施例的步骤903有区别于图13实施例的步骤803，该方法简要描述如下：
步骤901：解析码流获得第一指示信息，所述第一指示信息用于指示滤波器类型。具体实现可参考图13实施例的步骤801的描述，这里不再赘述。
步骤902：根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作(downsampling)，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块，第二亮度块表示第一亮度块中的亮度像素点下采样以后的集合。具体实现可参考图13实施例的步骤802的描述，这里不再赘述。
步骤903：获取模板色度点，以及根据所述第一指示信息获取模板亮度点。
本发明实施例中，对于模板亮度点，由于第一指示信息指示了滤波器类型，则可利用该滤波器类型对应的滤波器，对所述第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点。
举例来说，解码端设计有6种滤波器类型，且当前第一指示信息指示的值为0，则采用的亮度下采样滤波器为滤波器0，采样算法如下：
LC(xb,yb)＝(2*L(2*xb,2*yb)+L(2*xb-1,2*yb)+L(2*xb+1,2*yb)+2*L(2*xb,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb+1,2*yb+1)+4)>>3
所以，可利用该滤波器0，对第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点中的各个亮度像素点的值。
又举例来说，解码端设计有2种滤波器类型(如滤波器0和滤波器2)，且当前第一指示信息指示的值为1，则采用的亮度下采样滤波器为滤波器2，采样算法如下：
LC(xb,yb)＝(4*L(2*xb,2*yb)
+2*L(2*xb,2*yb+1)+2*L(2*xb,2*yb-1)+2*L(2*xb-1,2*yb)+2*L(2*xb+1,2*yb)
+L(2*xb+1,2*yb+1)+L(2*xb-1,2*yb+1)+L(2*xb-1,2*yb-1)+L(2*xb+1,2*yb-1)+8)>>4
所以，可利用该滤波器2，对第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点中的各个亮度像素点的值。
需要说明的是，上述例子仅仅是示例而非限定。
本发明实施例中，对于模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，模板色度点具体获取方法可参考上文图9和图10实施例的相关描述，这里不 再赘述。
步骤904：根据所述模板色度点和所述模板亮度点，获得线性模型系数α和β。具体实现可参考图13实施例的步骤804的描述，这里不再赘述。
步骤905：根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。具体实现可参考图13实施例的步骤805的描述，这里不再赘述。
可以看到，本发明实施例中，对于LM模式，解码端在导出模板亮度点的下采样过程以及对当前块的下采样过程中，可通过码流中的指示信息(如新增得SPS参数的值)来确定LM模式中当前色度块对应的亮度块下采样时采用的滤波器。从而可以得到与色度点采样位置相匹配的滤波器，有利于兼顾现实中不同视频序列可能存在不同的色度采样点位置的情况，保证下采样亮度点的位置与色度采样点位置具有一致性。
下面说明上述实施例中所示的编码方法以及解码方法的应用，以及使用所述编码方法和解码方法的系统。
图16示出用于实现内容分发服务的内容供应系统3100的框图。此内容供应系统3100包括捕获设备3102、终端设备3106，并且可选地包括显示器3126。捕获设备3102通过通信链路3104与终端设备3106通信。通信链路可以包括上文描述的通信信道13。通信链路3104包括但不限于WIFI、以太网、有线、无线(3G/4G/5G)、USB或其任何种类的组合等。
捕获设备3102生成数据，并可以通过如上述实施例中所示的编码方法对数据进行编码。可替换地，捕获设备3102可以将数据分发到流媒体服务器(图中未示出)，服务器对数据进行编码并将编码数据传输到终端设备3106。捕获设备3102包括但不限于相机、智能手机或平板电脑、计算机或笔记本电脑、视频会议系统、PDA、车载设备，或其中任何一个的组合等。例如，捕获设备3102可以包括如上文所述的源设备12。当数据包括视频时，包括在捕获设备3102中的视频编码器20可以实际执行视频编码处理。当数据包括音频(即，语音)时，包括在捕获设备3102中的音频编码器可以实际执行音频编码处理。对于一些实际场景，捕获设备3102通过将编码视频数据和编码音频数据一起复用来分发编码视频数据和编码音频数据。对于其它实际场景，例如在视频会议系统中，不复用编码音频数据和编码视频数据。捕获设备3102分别将编码音频数据和编码视频数据分发到终端设备3106。
在内容供应系统3100中，终端设备310接收并再现编码数据。终端设备3106可以是具有数据接收和恢复能力的设备，例如智能手机或平板电脑3108、计算机或笔记本电脑3110、网络视频录像机(network video recorder，NVR)/数字视频录像机(digital video recorder，DVR)3112、TV 3114、机顶盒(set top box，STB)3116、视频会议系统3118、视频监控系统3120、个人数字助理(personal digital assistant，PDA)3122、车载设备3124，或能够解码上述编码数据的以上设备中任何一个的组合等。例如，终端设备3106可以包括如上所述的目的地设备14。当编码数据包括视频时，包括在终端设备中的视频解码器30被优先化以执行视频解码。当编码数据包括音频时，包括在终端设备中的音频解码器被优先化以执行音频解码处理。
对于具有其显示器的终端设备，例如，智能手机或平板电脑3108、计算机或笔记本电脑3110、网络视频录像机(network video recorder，NVR)/数字视频录像机(digital video recorder，DVR)3112、TV 3114、个人数字助理(personal digital assistant，PDA)3122 或车载设备3124，终端设备可以将解码数据馈送到其显示器。对于不配备显示器的终端设备，例如STB 3116、视频会议系统3118或视频监控系统3120，在其中连接外部显示器3126以接收和显示解码数据。
当此系统中的每个设备执行编码或解码时，可以使用如上述实施例中所示的图像编码设备或图像解码设备。
图17示出终端设备3106的示例的结构的图。在终端设备3106从捕获设备3102接收到流之后，协议处理单元3202分析流的传输协议。所述协议包括但不限于实时流媒体协议(Real Time Streaming Protocol，RTSP)、超文本传送协议(Hyper Text Transfer Protocol，HTTP)、HTTP实时流媒体协议(HTTP Live streaming protocol，HLS)、MPEG-DASH、实时传输协议(Real-time Transport protocol，RTP)、实时消息传输协议(Real Time Messaging Protocol，RTMP)，或其任何种类的组合等。
在协议处理单元3202处理流之后，生成流文件。文件被输出到解复用单元3204。解复用单元3204可以将复用数据分离成编码音频数据和编码视频数据。如上文所述，对于其它实际场景，例如在视频会议系统中，不复用编码音频数据和编码视频数据。在这种情况下，编码数据被传输到视频解码器3206和音频解码器3208，而不通过解复用单元3204。
通过解复用处理，生成视频基本流(elementary stream，ES)、音频ES和可选的字幕。视频解码器3206，包括如上述实施例中说明的视频解码器30，通过如上述实施例中所示的解码方法对视频ES进行解码以生成视频帧，并将此数据馈送到同步单元3212。音频解码器3208对音频ES进行解码以生成音频帧，并将此数据馈送到同步单元3212。可替换地，在将视频帧馈送到同步单元3212之前可以将视频帧存储在缓冲器(图中未示出)中。类似地，在将音频帧馈送到同步单元3212之前可以将音频帧存储在缓冲器(图中未示出)中。
同步单元3212同步视频帧和音频帧，并将视频/音频提供给视频/音频显示器3214。例如，同步单元3212同步视频和音频信息的呈现。信息可以使用与编码音频和视觉数据的呈现有关的时间戳以及与数据流本身的传送有关的时间戳而以语法进行编码。
如果流中包括字幕，则字幕解码器3210对字幕进行解码，使字幕与视频帧和音频帧同步，并将视频/音频/字幕提供给视频/音频/字幕显示器3216。
本发明不限于上述系统，并且上述实施例中的图像编码设备或图像解码设备可以结合到其它系统中，例如汽车系统。
在上述实施例中，可以全部或部分地通过软件、硬件、固件或者任意组合来实现。当使用软件实现时，可以全部或者部分地以计算机程序产品的形式实现。所述计算机程序产品包括一个或多个计算机指令，在计算机上加载和执行所述计算机程序指令时，全部或部分地产生按照本发明实施例所述的流程或功能。所述计算机可以是通用计算机、专用计算机、计算机网络或其他可编程装置。所述计算机指令可存储在计算机可读存储介质中，或者从一个计算机可读存储介质向另一个计算机可读存储介质传输，例如，所述计算机指令可以从一个网络站点、计算机、服务器或数据中心通过有线(例如同轴电缆、光纤、数字用户线)或无线(例如红外、微波等)方式向另一个网络站点、计算机、服务器或数据中心进行传输。所述计算机可读存储介质可以是计算机能够存取的任何可用介质，也可以是包含一个或多个可用介质集成的服务器、数据中心等数据存储设备。所述可用介质可以是 磁性介质(例如软盘、硬盘、磁带等)、光介质(例如DVD等)、或者半导体介质(例如固态硬盘)等等。
在上述实施例中，对各个实施例的描述各有侧重，某个实施例中没有详述的部分，可以参见其他实施例的相关描述。

Claims (32)

  1. 一种色度块预测方法，其特征在于，所述方法包括：
    解析码流获得第一指示信息，所述第一指示信息用于指示滤波器类型；
    根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；
    获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；
    根据所述模板色度点和所述模板亮度点，获得线性模型系数；
    根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
  2. 根据权利要求1所述的方法，其特征在于，所述获取模板亮度点，包括：
    利用所述滤波器类型对应的滤波器，对所述第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点。
  3. 根据权利要求1-2任一项所述的方法，其特征在于，所述模板色度点具体包括：
    所述当前色度块相邻左边一列或者左边多列的色度像素点。
  4. 根据权利要求1-2任一项所述的方法，其特征在于，所述模板色度点具体包括：
    所述当前色度块相邻上边一列或者上边多列的色度像素点。
  5. 根据权利要求1-4任一所述的方法，其特征在于，所述模板色度点具体包括：
    所述当前色度块相邻上边一行或者上边多行的色度像素点，以及，所述当前色度块相邻左边一列或者左边多列的色度像素点。
  6. 根据权利要求1-5任一项所述的方法，其特征在于，所述获取模板色度点和模板亮度点之前，所述方法还包括：
    解析所述码流获得第二指示信息，所述第二指示信息用于指示当前解码采用的帧内预测模式为线性模型LM模式。
  7. 根据权利要求1-6任一项所述的方法，其特征在于，
    所述方法用于解码视频序列中的当前图像块，所述当前图像块包括所述第一亮度块和所述当前色度块，所述视频序列中的图像为4:2:0格式或者4:2:2格式。
  8. 一种色度块预测方法，其特征在于，所述方法包括：
    根据当前色度块的采样点位置确定滤波器类型；
    根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块， 所述第一亮度块是当前色度块对应的亮度块；
    获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；
    根据所述模板色度点和所述模板亮度点，获得线性模型系数；
    根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
  9. 根据权利要求8所述的方法，其特征在于，所述根据当前色度块的采样点位置确定滤波器类型之前，包括：
    解析码流获得第一指示信息，所述第一指示信息用于指示所述当前色度块的采样点位置。
  10. 根据权利要求9所述的方法，其特征在于，所述解析码流获得第一指示信息，包括：
    解析码流中的序列参数集(SPS)参数，获得所述第一指示信息。
  11. 一种色度块预测方法，其特征在于，所述方法包括：
    根据当前色度块的采样点位置类型确定滤波器类型；
    设置第一指示信息，所述第一指示信息用于指示所述滤波器类型；
    将所述第一指示信息编入码流。
  12. 根据权利要求11所述的方法，其特征在于，所述当前色度块的采样点位置类型为以下采样点位置类型中的至少一种：
    采样点位置类型type0、采样点位置类型type1、采样点位置类型type2、采样点位置类型type3、采样点位置类型type4、采样点位置类型type5。
  13. 根据权利要求11所述的方法，其特征在于，所述当前色度块的采样点位置类型为以下采样点位置类型中的至少一种：
    采样点位置类型type0、采样点位置类型type2。
  14. 根据权利要求11-13任一项所述的方法，其特征在于，所述方法还包括：
    从多个帧内预测模式中选择线性模型LM模式；
    设置第二指示信息，所述第二指示信息用于指示所述线性模型LM模式；
    将所述第二指示信息编入所述码流。
  15. 根据权利要求11-14任一项所述的方法，其特征在于，所述方法还包括：
    根据所述第一指示信息，确定所述滤波器类型对应的滤波器；
    根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样，获得第二亮度块，所 述第一亮度块是所述当前色度块对应的亮度块；
    获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点下采样获得；
    根据所述模板色度点和所述模板亮度点，获得线性模型系数；
    根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
  16. 一种用于解码视频数据的设备，所述设备包括：
    存储器，用于存储码流形式的视频数据；
    解码器，用于：
    解析码流获得第一指示信息，所述第一指示信息用于指示滤波器类型；
    根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；
    获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；
    根据所述模板色度点和所述模板亮度点，获得线性模型系数；
    根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
  17. 根据权利要求16所述的设备，其特征在于，
    所述解码器具体用于：
    利用所述滤波器类型对应的滤波器，对所述第一亮度块相邻的多个亮度像素点进行下采样操作，获得所述模板亮度点。
  18. 根据权利要求15或16所述的设备，其特征在于，
    所述模板色度点具体包括：所述当前色度块相邻左边一列或者左边多列的色度像素点。
  19. 根据权利要求15或16所述的设备，其特征在于，
    所述模板色度点具体包括：所述当前色度块相邻上边一列或者上边多列的色度像素点。
  20. 根据权利要求16-19任一项所述的设备，其特征在于，
    所述模板色度点具体包括：所述当前色度块相邻上边一行或者上边多行的色度像素点，以及，所述当前色度块相邻左边一列或者左边多列的色度像素点。
  21. 根据权利要求16-20任一项所述的设备，其特征在于，所述解码器还用于：
    解析所述码流获得第二指示信息，所述第二指示信息用于指示当前解码采用的帧内预测模式为线性模型LM模式。
  22. 根据权利要求16-21任一项所述的设备，其特征在于，
    所述解码器用于解码视频序列中的当前图像块，所述当前图像块包括所述第一亮度块和所述当前色度块，所述视频序列中的图像为4:2:0格式或者4:2:2格式。
  23. 一种用于解码视频数据的设备，所述设备包括：
    存储器，用于存储码流形式的视频数据；
    解码器，用于：
    根据当前色度块的采样点位置确定滤波器类型；
    根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样操作，获得第二亮度块，所述第一亮度块是当前色度块对应的亮度块；
    获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点进行下采样操作获得；
    根据所述模板色度点和所述模板亮度点，获得线性模型系数；
    根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
  24. 根据权利要求23所述的设备，其特征在于，所述解码器具体用于：在所述根据当前色度块的采样点位置确定滤波器类型之前，解析码流获得第一指示信息，所述第一指示信息用于指示所述当前色度块的采样点位置。
  25. 根据权利要求24所述的设备，其特征在于，所述解码器具体用于：解析码流中的序列参数集(SPS)参数，获得所述第一指示信息。
  26. 一种用于编码视频数据的设备，所述设备包括：
    存储器，用于存储码流形式的视频数据；
    编码器，用于：
    根据当前色度块的采样点位置类型确定滤波器类型；
    设置第一指示信息，所述第一指示信息用于指示所述滤波器类型；
    将所述第一指示信息编入码流。
  27. 根据权利要求26所述的设备，其特征在于，所述当前色度块的采样点位置类型为以下采样点位置类型中的至少一种；
    采样点位置类型type0、采样点位置类型type1、采样点位置类型type2、采样点位置类型type3、采样点位置类型type4、采样点位置类型type5。
  28. 根据权利要求26所述的设备，其特征在于，所述当前色度块的采样点位置类型为以下采样点位置类型中的至少一种；
    采样点位置类型type0、采样点位置类型type2。
  29. 根据权利要求26-28任一项所述的设备，其特征在于，所述编码器还用于：
    从多个帧内预测模式中选择线性模型LM模式；
    设置第二指示信息，所述第二指示信息用于指示所述线性模型LM模式；
    将所述第二指示信息编入所述码流。
  30. 根据权利要求26-29任一项所述的设备，其特征在于，所述编码器还用于：
    根据所述第一指示信息，确定所述滤波器类型对应的滤波器；
    根据所述滤波器类型对应的滤波器，对第一亮度块进行下采样，获得第二亮度块，所述第一亮度块是所述当前色度块对应的亮度块；
    获取模板色度点和模板亮度点，所述模板色度点包括所述当前色度块相邻的多个色度像素点，所述模板亮度点通过对所述第一亮度块相邻的多个亮度像素点下采样获得；
    根据所述模板色度点和所述模板亮度点，获得线性模型系数；
    根据所述第二亮度块和所述线性模型系数，获得所述当前色度块的预测值。
  31. 一种解码设备，包括：相互耦合的非易失性存储器和处理器，所述存储器用于存储程序指令，所述程序指令使得所述处理器执行权利要求1-7任一项所述的方法，或者，所述程序指令使得所述处理器执行权利要求8-10任一项所述的方法。
  32. 一种编码设备，包括：相互耦合的非易失性存储器和处理器，所述存储器用于存储程序指令，所述程序指令使得所述处理器执行权利要求8-12任一项所述的方法。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113365067A (zh) * 2021-05-21 2021-09-07 中山大学 基于位置加权的色度线性预测方法、装置、设备及介质

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP3843399B1 (en) * 2018-10-12 2023-09-06 Guangdong Oppo Mobile Telecommunications Corp., Ltd. Video image component prediction method and apparatus, and computer storage medium
WO2020226359A1 (ko) * 2019-05-03 2020-11-12 한국전자통신연구원 영상 부호화/복호화 방법, 장치 및 비트스트림을 저장한 기록 매체
CN113497937B (zh) * 2020-03-20 2023-09-05 Oppo广东移动通信有限公司 图像编码方法、图像解码方法及相关装置
CN115834912A (zh) * 2020-06-03 2023-03-21 北京达佳互联信息技术有限公司 对视频进行编码的方法和装置
WO2024061136A1 (en) * 2022-09-19 2024-03-28 Douyin Vision Co., Ltd. Method, apparatus, and medium for video processing

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103096057A (zh) * 2011-11-08 2013-05-08 华为技术有限公司 一种色度帧内预测方法和装置
CN103369315A (zh) * 2012-04-06 2013-10-23 华为技术有限公司 色度分量的帧内预测模式的编码、解码方法、设备及系统
CN103782596A (zh) * 2011-06-28 2014-05-07 三星电子株式会社 使用图像的亮度分量的对图像的色度分量的预测方法和设备
CN107211121A (zh) * 2015-01-22 2017-09-26 联发科技（新加坡）私人有限公司 色度分量的视频编码方法
CN107409209A (zh) * 2015-03-20 2017-11-28 高通股份有限公司 用于线性模型预测模式的降取样处理
WO2018053293A1 (en) * 2016-09-15 2018-03-22 Qualcomm Incorporated Linear model chroma intra prediction for video coding

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107105305B (zh) * 2011-06-24 2020-04-03 Lg 电子株式会社 图像信息编码和解码方法
US9807403B2 (en) * 2011-10-21 2017-10-31 Qualcomm Incorporated Adaptive loop filtering for chroma components

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103782596A (zh) * 2011-06-28 2014-05-07 三星电子株式会社 使用图像的亮度分量的对图像的色度分量的预测方法和设备
CN103096057A (zh) * 2011-11-08 2013-05-08 华为技术有限公司 一种色度帧内预测方法和装置
CN103369315A (zh) * 2012-04-06 2013-10-23 华为技术有限公司 色度分量的帧内预测模式的编码、解码方法、设备及系统
CN107211121A (zh) * 2015-01-22 2017-09-26 联发科技（新加坡）私人有限公司 色度分量的视频编码方法
CN107409209A (zh) * 2015-03-20 2017-11-28 高通股份有限公司 用于线性模型预测模式的降取样处理
WO2018053293A1 (en) * 2016-09-15 2018-03-22 Qualcomm Incorporated Linear model chroma intra prediction for video coding

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
CHEN: "CE6.a.4: Chroma intra prediction by reconstructed luma samples", JOINT COLLABORATIVE TEAM ON VIDEO CODING (JCT-VC) OF ITU-T SG 16 WP3 AND ISO/ IEC JTC1/SC29/WG11 5TH MEETING, 16 March 2011 (2011-03-16), Geneva, XP030008389 *

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113365067A (zh) * 2021-05-21 2021-09-07 中山大学 基于位置加权的色度线性预测方法、装置、设备及介质
CN113365067B (zh) * 2021-05-21 2023-03-14 中山大学 基于位置加权的色度线性预测方法、装置、设备及介质

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