Abstract: A context modeling method includes: determining, for a current block, whether a first preset condition is satisfied and whether a second preset condition is satisfied, where the first preset condition is a preset condition related to a first neighboring block neighboring to the current block in a first direction, the second preset condition is a preset condition related to a second neighboring block neighboring to the current block in a second direction; determining a subclass index of a context model of a first flag of the current block based on the height and the width of the current block; and determining the context model of the first flag of the current block based on a satisfaction status of the first preset condition, a satisfaction status of the second preset condition, and the subclass index of the context model of the first flag.

Abstract: Illumination compensation can be performed for inter prediction coding of a picture, e.g. for video encoding and decoding. The illumination compensation may include: obtaining inter-predicted sample values for a current block of the picture; obtaining a first target value and a second target value of neighboring samples from a set of neighboring samples of a reference block, wherein the set includes neighboring samples of at least one reference block of the current block, and obtaining corresponding positions A of the sample having the first target value and B of the sample having the second target value relative to the position of the reference block; obtaining respective values of neighboring samples of the current block at the obtained positions A and B relative to the position of the current block; obtaining values of updating parameters using the calculated values; and updating the inter-predicted sample values based on the updating parameters.

Abstract: An image prediction method, apparatus, and system, a device, and a storage medium are provided. The method includes: (401) obtaining a split mode of a current node, where the current node is an image block in a coding tree unit in a current image; (402) determining, based on the split mode of the current node and a size of the current node, whether the current node satisfies a first condition; and (403) when it is determined that the current node satisfies the first condition, performing intra prediction on all coding blocks belonging to the current node, to obtain predictors of all the coding blocks belonging to the current node.

Abstract: The present disclosure relates to intra- or inter-prediction for video encoding and decoding. For that purpose, an apparatus and methods obtain a reference sample and a subpixel offset value. A 4-tap interpolation filter is used to filter the reference sample to obtain a predicted sample value. The filter coefficients c0, c1, c2, and c3 of the 4-tap interpolation filter satisfy subpixel offset.

Abstract: A method of decoding a coded video bitstream implemented by a video decoder is disclosed. The method includes determining that a coded video sequence (CVS) of the coded video bitstream includes a video coding layer (VCL) network abstraction layer (NAL) unit having a gradual decoding refresh (GDR) network abstraction layer (NAL) unit type (GDR_NUT), the VCL NAL unit having the GDR_NUT containing a GDR picture; initiating decoding of the CVS at the GDR picture; and generating an image according to the CVS as decoded. A corresponding method of encoding is also disclosed.

Abstract: The present disclosure provides a method of video coding implemented in a decoding device or an encoding device, the method comprising: determining a block size of a current coding block, the current coding block being coded in intra prediction mode; selecting, based on the determined block size of the current coding block, a sub-partitioning rule that determines a number of sub-partitions and a partition direction into which the current coding block is to be divided; and dividing the current coding block into sub-partitions based on the selected sub-partitioning rule.

Abstract: A method of point cloud coding (PCC) implemented by a decoder is provided. The method includes receiving, by a receiver of the decoder, a bitstream containing a patch rotation enabled flag and atlas information for a two dimensional (2D) patch; determining, by a processor of the decoder, that the 2D patch is capable of being rotated based on the patch rotation enabled flag; rotating, by the processor, the 2D patch; and reconstructing, by the processor, a three dimensional (3D) image using the atlas information and the 2D patch as rotated.

Abstract: A device for video decoding can be configured to obtain, from a syntax structure in a bitstream comprising an encoded representation of the video data, a syntax element indicating whether 6-parameter affine prediction is enabled for blocks corresponding to the syntax structure, wherein the blocks corresponding to the syntax structure comprise a first block; based on the syntax element indicating that the 6-parameter affine prediction is enabled for the blocks corresponding to the syntax structure, use the 6-parameter affine prediction to generate a predictive block for the first block; and use the predictive block and residual data to reconstruct the first block.

Abstract: The present disclosure provides methods and devices of processing a block according to a merge candidate list, the method comprising: constructing a first list according to motion information of neighboring blocks of a current block; obtaining prediction information of the current block; when the prediction information of the current block indicates that a sub-block prediction is applied to the current block, obtaining a uni-prediction candidate for the current block according to the first list; using, the uni-prediction candidate for the current block to perform inter prediction of the current block. According to embodiment of the present disclosure, the regular merge list can be directly used and there is no need to explicitly generate the uni-prediction merge candidate list for sub-block prediction.

Abstract: A video coding mechanism is disclosed. The mechanism includes receiving a bitstream including image data coded in a plurality of slices. A top left tile identifier (ID) and a bottom right tile ID of a first slice are determined. Boundaries of the first slice are determined based on the top left tile ID and the bottom right tile ID. The first slice is decoded to generate a reconstructed image based on the boundaries of the first slice.

Abstract: The present disclosure provides apparatuses and methods for splitting an image into coding units. An image is divided into coding tree units (CTUs) which are hierarchically partitioned. Hierarchical partitioning includes multi-type partitioning such as binary tree or quad tree splitting. For CTUs completely within the image and CTUs on the boundary, respective multi-type partition depths are chosen. The present disclosure provides for multi-type partitioning flexibility in a boundary portion of the image.

Abstract: A method of video coding, wherein the method comprises inter-prediction processing of a first block, wherein the inter-prediction processing comprises subpixel interpolation filtering of samples of a reference block; intra-prediction processing of a second block, wherein the intra-prediction processing comprises subpixel interpolation filtering of reference samples; wherein the method further comprises selecting interpolation filter coefficients for the subpixel interpolation filtering based on a subpixel offset between integer reference sample positions and fractional reference samples' positions, wherein for the same subpixel offsets the same interpolation filter coefficients are selected for intra-prediction processing and inter-prediction processing.

Abstract: The present disclosure provides a chroma block prediction method and a device. The method includes: parsing a bitstream to obtain first indication information; downsampling a first luma block by a first filter when a value of the first indication information is a first value or by using a second filter when a value of the first indication information is a second value, to obtain a second luma block; obtaining a plurality of chroma samples and a plurality of luma samples; obtaining linear model coefficients based on the plurality of chroma samples and the plurality of luma samples; and obtaining a prediction value of the current chroma block based on the second luma block and the linear model coefficients.

Abstract: The present disclosure provides a coding method, wherein the coding includes decoding or encoding, and the method comprises determining whether a current coding unit is predicted by application of combined inter-intra prediction (CIIP); and in response to determining that the current coding unit is predicted by application of CIIP, setting a boundary strength of a boundary of the current coding unit to a first value.

Abstract: This application provides a motion vector obtaining method and apparatus. The method includes: determining a target offset vector of a block and identifier information of a target picture, wherein the block comprises at least one sub-block; determining a location of the sub-block; determining, as a target location coordinate value of a collocated sub-block, a location coordinate value obtained by performing a clipping operation on an initial location coordinate value in a range, wherein the initial location coordinate value is based on the location of the sub-block and the target offset vector; and obtaining a motion vector of the sub-block based on a motion vector corresponding to the target location coordinate value. Thus, a range of the target offset vector is limited, so that a quantity of memory read times can be reduced in a process of obtaining the motion vector of the collocated sub-block.

Abstract: A deblocking method, for deblocking a transform block boundary within a coding block in an image encoding and/or an image decoding is provided, wherein the coding block comprising transform blocks is coded in inter prediction mode and the transform blocks comprises a first transform block and a second transform block. The method comprises: determining, when the boundary between the first transform block and the second transform block is a transform block boundary and at least one of the first transform block and the second transform block has one or more non-zero transform coefficients, a value of a BS parameter for the boundary between the first transform block and the second transform block to be a first value; and performing de-blocking filtering process to the boundary between the first transform block and the second transform block at least based on the value of the boundary strength parameter.

Abstract: Provided are a method, an apparatus, a computer program product and a non-transitory computer-readable medium for video coding. The method comprises performing an intra-prediction process of a block comprising samples to be predicted, wherein an interpolation filter is applied to reference samples of the block during the intra-prediction process of the block. The interpolation filter is selected on the basis of a subpixel offset between the reference samples and the samples to be predicted, and a size of a main reference side used in the intra-prediction process is determined according to a length of the interpolation filter and an intra-prediction mode that provides, out of a 10 set of available intra-prediction modes, the greatest non-integer value of said subpixel offset, wherein the main reference side comprises the reference samples.

Abstract: Devices and methods of directional intra prediction for chroma component of a picture are provided. The method includes obtaining an initial intra prediction mode of the chroma component, and deriving a chroma intra prediction mode (intraPredModeC) from a look up table (LUT) by using the initial intra prediction mode of the chroma component. The chroma component has different subsampling ratios in horizontal and vertical directions. The method further includes performing wide-angle mapping on the chroma intra prediction mode (intraPredModeC) to obtain a modified intraPredModeC; obtaining an angle parameter for the chroma component based on the modified intraPredModeC; and obtaining predicted samples of the chroma component based on the angle parameter. The method provides the minimum number of entries in the LUT that is used to determine chroma intra prediction mode from the initial chroma intra prediction mode.

Abstract: A video decoding method, including: parsing a received bitstream to obtain prediction information of a coding unit (CU); obtaining a target transform mode of a residual transform unit (TU); parsing the received bitstream to obtain transform coefficients of the residual TU; applying an inverse quantization to the transform coefficients of the residual TU to obtain dequantized coefficients; applying, based on the target transform mode, an inverse transform to the dequantized coefficients to obtain a residual block of the residual TU; obtaining a prediction block of the CU based on the prediction information; obtaining a video block based on the residual block and the prediction block; and outputting a video sequence including a video frame that includes the video block.

Abstract: An image processing device for use in an image encoder and/or an image decoder, for deblocking a block edge between a first block and a second block of an image encoded with a block code, is provided. The image processing device comprises a filter for filtering the block edge, configured to, for at least some of the pixels to be filtered, within a deblocking range from the block edge, the deblocking range being perpendicular to the block edge, determine a filtered pixel value from an original pixel value of the pixel and at least one further pixel value, determine a clipping value of the pixel, dependent upon a distance of the pixel from the block edge, and clip the filtered pixel value, using the clipping value resulting in a deblocked pixel value.