Abstract: A non-transitory computer-readable medium for inter-prediction and an encoder are provided. An initial motion vector is obtained for a current block. Search space positions are determined according to the initial motion vector. Matching costs for the search space positions are checked according to a checking order to select a target search space position with a minimal matching cost. A refining motion vector of the current block is determined based on the initial motion vector and the target search space position. A central search space position is determined according to the checking order, and the central search space position is pointed to by the initial motion vector.

Abstract: A partitioning method comprises determining whether a current block of a picture is a boundary block and whether the size of the current block is larger than a minimum allowed quadtree leaf node size; and if the current block is the boundary block and the size of the current block is not larger than the minimum allowed quadtree leaf node size (MinQTSize), applying forced binary tree (BT) partitioning to the current block. A method comprises making a determination that a current block of a picture is a boundary block and that a size of the current block is less than or equal to a minimum allowed quadtree (QT) leaf node size (MinQTSize); and applying, in response to the determination, forced binary tree (BT) partitioning to the current block.

Abstract: The present disclosure relates to the field of picture processing. Especially, the disclosure deals with improving the prediction of a block of a picture when decoding or encoding. A method of coding a block of a picture, comprising: obtaining an indication parameter for a current coding block. The indication parameter represents whether a multi-hypothesis prediction is applied to the current coding block. When the indication parameter represents that the multi-hypothesis prediction is applied to the current coding block, coding the current coding block according to a planar mode.

Abstract: A method for deblocking a chroma block edge between a first chroma block of a first image block and a second chroma block of a second image block. The method includes a decision process which includes: determining a first chroma quantization parameter for the first chroma block based on a first luma quantization parameter of a first luma block of the first image block and a chroma QP mapping table for the first chroma block; determining a second chroma quantization parameter for the second chroma block based on a second luma quantization parameter of a second luma block of the second image block and a chroma QP mapping table for the second chroma block; determining an averaged and rounded chroma quantization parameter based on the first chroma quantization parameter and the second chroma quantization parameter; and determining a threshold parameter based on the averaged and rounded chroma quantization parameter.

Abstract: A method of filtering a sample value of a picture is provided, with an integer t that is less than k and with an integer j in the range of 1 to m: generating, with an integer i in the range of 1 to k?t?1, a filtered sample value by applying a filter to the value of the sample p(i,j), wherein the filter is supported by a set of filter support samples, the set of filter support samples does not comprise any samples p(i?,j?) with row index i? greater than k?t?1, and/or generating, with an integer i in the range of k?t to k, a filtered sample value by applying a filter to the value of the sample p(i,j), the filter is supported by a set of filter support samples, wherein the set of filter support samples does not comprise any samples p(i?,j?) with row index i? less than k?t.

Abstract: A deblocking method is provided for deblocking a sub-partition boundary within a coding block during image encoding and/or image decoding process. The coding block is coded in an intra prediction mode and the coding block is partitioned into sub-partitions comprising a first sub-partition and a second sub-partition that is adjacent to the first sub-partition. The method comprises: determining a maximum filter length to be 1 for a first/second sub-partition when a width of the first or second sub-partition is 4 samples, or when a height of the first or second sub-partition is 4 samples; modifying a value of up to one sample of the first or second sub-partition, wherein the value of the up to one sample is obtained from a row or a column of the first or second sub-partition that is perpendicular to and adjacent to the sub-partitions boundary between the first sub-partition and the second sub-partition.

Abstract: A deblocking method is provided for deblocking a sub-partition boundary within a coding block during image encoding and/or image decoding process. The coding block is coded in an intra prediction mode and the coding block is partitioned into sub-partitions comprising a first sub-partition and a second sub-partition that is adjacent to the first sub-partition. The method comprises: determining a maximum filter length to be 1 for a first/second sub-partition when a width of the first or second sub-partition is 4 samples, or when a height of the first or second sub-partition is 4 samples; modifying a value of up to one sample of the first or second sub-partition, wherein the value of the up to one sample is obtained from a row or a column of the first or second sub-partition that is perpendicular to and adjacent to the sub-partitions boundary between the first sub-partition and the second sub-partition.

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; wherein 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: A method of video coding a block of a picture includes: obtaining a residual signal resulting from inter- or intra-picture prediction; inferring use of a DCT2 transform core for a sequence of the residual signal; processing the transformation of the block using the inferred transform core.

Abstract: An apparatus and a method for filtering reconstructed images, in particular, video images, with adaptive multiplicative filters. The efficiency of the filtering operation is increased by restricting the allowable values of the filter coefficients to those that have only a limited number of “ones” in the binary representation.

Abstract: A coding apparatus configured to select an intra prediction mode for a current block, encode the selected intra prediction mode using truncated binary coding every time the selected intra prediction mode is a remaining mode, and encode the selected intra prediction mode using N bits when the selected intra prediction mode is included in a first portion from remaining modes and using N+1 bits when the selected intra prediction mode is included in a second portion of the remaining modes.

Abstract: The present invention relates to the performance of motion vector refinement in a search space for multi-reference inter-prediction. Two or more reference pictures are selected, one of those used for motion vector refinement. Based on an initial estimate of a motion vector to the reference picture for motion vector refinement, a search space in this reference image is constructed. Using template matching, the first motion vector is refined. The second motion vector to another reference picture is calculated using its initial estimate, the initial estimate of the first motion vector and the refined first motion vector.

Abstract: The present disclosure relates to motion vector refinement. As a first step, an initial motion vector and a template for the block are obtained. Then, the refinement of the initial motion vector is determined by template matching with said template in a search space. The search space is located on a position given by the initial motion vector and includes one or more fractional sample positions, wherein each of the fractional sample positions belonging to the search space is obtained by interpolation filtering with a filter of a predefined tap-size assessing integer samples only within a window, said window being formed by integer samples accessible for the template matching in said search space.

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.

Abstract: A method of coding implemented by a decoding device or an encoding device, comprising obtaining indication information for a luma position (cbWidth/2, cbHeight/2) of a current coding block, relative to a top-left luma sample position (xCb, yCb) of the current coding block; setting a value of a luma intra prediction mode associated with the current coding block to a first default value, when the indication information indicates that an Intra Block Copy (IBC) mode or palette mode is applied for the luma component at the luma position (cbWidth/2, cbHeight/2), relative to the top-left luma sample position (xCb, yCb) of the current coding block; and obtaining a value of a chroma intra prediction mode based on the value of the luma intra prediction mode of the current coding block.

Abstract: A decoding method and a decoder for decoding a current block of a video frame is provided, wherein the decoding method comprises determining a list of Most Probable Modes (MPMs) for the current block. When at least one condition is satisfied, the list of MPMs includes a DC mode, a Vertical mode, a Horizontal mode, an intra prediction mode corresponding to a value of the Vertical mode with a first offset, and an intra prediction mode corresponding to the value of the Vertical mode with a second offset. The decoding method further includes obtaining a MPM flag and a MPM index for the current block from a bitstream of the video, and obtaining an intra prediction mode for the current block for reconstructing the current block.

Abstract: A video processing method, comprising: initializing a HMVP list for a current CTU row when the current CTU is the beginning CTU of a current CTU row; and processing the current CTU row based on the HMVP list. By performing the method, the encoding efficiency and decoding efficiency are improved.

Abstract: An apparatus and a method for filtering reconstructed images, in particular, video images, with adaptive multiplicative filters. The efficiency of the filtering operation is increased by restricting the allowable values of the filter coefficients to those that have only a limited number of “ones” in the binary representation.

Abstract: A method of decoding of a picture from a video bitstream is disclosed. The video bitstream includes a slice header of a current slice and data representing the current slice. The method comprises: obtaining a parameter used to derive a number of tiles in the current slice from the slice header when a slice address of the current slice is not an address of a last tile in the picture where the current slice located; and reconstructing the current slice using the number of tiles in the current slice and the data representing the current slice.

Abstract: A method of video coding a block of a picture includes: obtaining a residual signal resulting from inter- or intra-picture prediction; inferring use of a DCT2 transform core for a sequence of the residual signal; processing the transformation of the block using the inferred transform core.