Abstract: Video processing can involve encoding and/or decoding a picture based on determining an activation of a processing mode involving a motion vector refinement process and a second process other than the motion vector refinement process; modifying the motion vector refinement process based on the activation and the second process; and encoding and/or decoding the picture based on the modified motion vector refinement process and the second process.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding are presented. According to an implementation, in a method for encoding or decoding a part of an image, at least an equation of the bi-directional optical flow is modified for unequal weights in a weighted prediction of the part of the image. According to non-limiting examples, modifying the bi-directional optical flow equation comprises bit depth shifting the unequal weights used in the weighted prediction, quantifying the unequal weighs used in the weighted prediction or deriving modified weighs to apply to predictions of the part of the image from the unequal weights used in weighted prediction.

Abstract: Images to be used as reference images in an adaptive resolution coder or decoder undergo resizing to match the resolution of an image being processed. The resizing process is carried out using extended resolution bit lengths to more accurately represent the processed image. The internal bit depth is retained through the resizing process, and kept as a reference image is stored. When a reference image is used in motion compensation processing, the resized reference matches the resolution of a current image being processed and has an expanded bit depth precision to achieve better fidelity.

Abstract: In some coding modes, such as the merge mode, a list of motion candidates is generated using spatial or temporal neighboring blocks or constructed ones, and one of the motion candidates is inherited by the current block. When constructing the list of motion candidates, motion information of a candidate to be added is checked to limit the redundancy in the constructed list. In one implementation, the switchable interpolation filter, the IFindex becomes part of the motion information to be used in comparison since it can modify the resulting prediction. Furthermore, the GBiIdx indicating the weights used in bi-prediction can also be part of the motion information to be compared and could also be taken into account in the redundancy check. In general, all or part of motion information that causes different prediction can be used in redundancy check.

Abstract: Different implementations are described for determining one or more illumination compensation parameters for a current block being encoded by a video encoder or decoded by a video decoder, based on the selection of one or more neighboring samples. The selection of the one or more neighboring samples is based on information used to reconstruct a plurality of neighboring reconstructed blocks. The selection may be based on the motion information, such as motion vector and reference picture information. In one example, only samples from neighboring reconstructed blocks that have (1) the same reference picture index and/or (2) a motion vector close to the motion vector of the current block is selected. In another example, if the current block derives or inherits some motion information from a top or left neighboring block, then only the top or left neighboring samples are selected for IC parameter calculation.

Abstract: Methods (1100, 1300) and apparatuses (600, 1200) for video coding and decoding are provided. The method of video encoding includes accessing (1110) a reconstructed block corresponding to a block in a picture of a video, determining (1120) at least one filter pattern based on a property of the block and filtering (1130) the reconstructed block according to the at least one filter pattern. The method of video decoding includes accessing (1310) a reconstructed block corresponding to a block in a picture of an encoded video, determining (1320) at least one filter pattern based on a property of the block and filtering (1330) the reconstructed block according to the at least one filter pattern. A bitstream formatted to include encoded data, a computer-readable storage medium and a computer program product are also described.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding are presented including a method for deblocking an image. According to an implementation, in a method for deblocking an image, at least one boundary is determined between a first block of samples and a second block of samples; a boundary strength is determined according to at least one of a prediction mode of the first block and a prediction mode of the second block; and samples of the first and second blocks neighboring the at least one boundary are filtered according to the boundary strength. Advantageously, in case the prediction mode of the first block is a weighted prediction mode, the boundary strength further depends on the relative weight of samples used in predicting the first block of samples according to the weighted prediction mode of the first block and reciprocally for the second block.

Abstract: A decoding method is presented. At least one high level syntax element is decoded that indicates whether generalized bi-prediction applies for predicting blocks of a slice. A block is then decoded from said slice using generalized bi-prediction in the case where said at least one high level syntax element indicates to apply generalized bi-prediction.

Abstract: A Local illumination compensation system for video encoding and decoding uses memory for storing illumination compensation parameters and does not require access to reconstructed pixels of neighboring blocks. A set of illumination compensation parameters is stored in a dedicated buffer, which is of limited size, and which is decoupled from the coding unit level storage of information. The buffer contains a set of illumination compensation parameters, which may be, for example, computed (or determined in some other manner) on the fly or determined beforehand (for example for example obtained from the video signal or from a device).

Abstract: Different implementations are described, particularly implementations for video encoding and decoding using block extension for overlapped block motion compensation. The method comprises: obtaining for a current block of a picture to be encoded or decoded an extended portion corresponding to at least one portion of a neighboring block, the at least one portion being adjacent to the current block; forming an extended block using the current block and the extended portion; and performing a prediction to determine prediction samples for the extended block.

Abstract: A decoding method is disclosed. A quantization parameter of at least one luma block is obtained. The at least one luma block comprises a luma sample co-located with at least one chroma sample selected in a current chroma block. The luma and chroma blocks are coded in dual tree mode. A quantization parameter of the current chroma block is then determined responsive to the quantization parameter of the at least one luma block. Finally, the current chroma block is decoded using the quantization parameter of the current chroma block.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding using entropy coding of quantized transform coefficients. The method comprises: determining context model indices for one or more syntax elements of quantized transform coefficients of a transform block, wherein different context model indices are obtained for quantized transform co-efficients in different regions of the transform block and a single context index is used for at least one region of the transform block; and selecting for the one or more syntax elements associated with a particular quantized transform coefficient one of several context models based on the determined content model index.

Abstract: In general, encoding or decoding a picture part can involve determining a spatiotemporal motion vector predictor (STMVP) candidate for a merge mode of operation from spatial motion vector candidates taken from spatial positions around a current coding unit (CU) and a temporal motion vector candidate, where at least one embodiment involves determining the STMVP candidate based on considering at most two spatial positions and based on an average of at least two of the spatial and temporal motion vector candidates.

Abstract: A decoding method is disclosed. It comprises: —decoding parameters for a current block; —disabling a first coding tool for said current block in the case where one or more of the following conditions is verified: a second coding tool is used for said current block and a given condition on the decoded parameters is verified; —enabling for said current block said first coding tool otherwise; and —decoding said current block using said first coding tool if said first coding tool is enabled.

Abstract: An encoding method for encoding blocks of a picture part is disclosed in an embodiment. A reconstructed version of each block of the picture part, called reconstructed block, is determined. A plurality of candidate sets of filter parameters is obtained and an index is determined for each block of the picture part that identifies one of the candidate sets of filter parameters to be used for filtering the block. Each reconstructed block is filtered with the candidate set of filter parameters of the plurality of candidate sets of filter parameters identified by the index. The plurality of candidate sets of filter parameters, the blocks of the picture part and the index for each block are encoded in a bitstream. Advantageously, a plurality of candidate sets of filter parameters are determined such as to minimize a rate-distortion cost for each block of the picture part.

Abstract: A method for encoding a LUT defined as a lattice of vertices is disclosed. At least one value is of each vertex of the lattice. The method comprises for a current vertex: predicting the at least one value of said current vertex from another value which is for example obtained from reconstructed values of neighboring vertices; and encoding in a bitstream at least one residue computed between the at least one value of the current vertex and its prediction in a bitstream.

Abstract: An image is split into a plurality of blocks of various sizes and a subdivision level counter is associated to each of the blocks. The value of this subdivision level counter for a block is representative of the size of the block and is used to determine the quantization parameter for the block. The value is propagated for each subdivision and incremented according the type of the subdivision. When the image is split, an analysis is done according to the subdivision level counter, a maximal value of subdivision and the type of split, in order to determine the start of a new quantization group and when it is the case, the current position of the partition is propagated to the further split partitions to be stored with these partition and serve in the prediction process when decoding.

Abstract: In general, encoding or decoding a picture part can involve a first CABAC probability model associated with a first flag indicating use of an affine mode and a second CABAC probability model associated with a second flag indicating use of either the affine mode or a second mode different from the affine mode, where the first and second CABAC probability models are different and are determined independently.

Abstract: A decoding method is presented. An illumination compensation parameter is first determined for a current block of a picture. The illumination compensation parameter is determined from one or more illumination compensation parameters or from one or more reconstructed samples of at least one spatially neighbor block only in the case where said at least one spatially neighbor block belongs to the same local illumination compensation group as the current block, called current local illumination compensation group. Finally, the current block is reconstructed using the determined illumination compensation parameter.

Abstract: Encoding or decoding video information can involve, for example, partitioning a coding unit of the video information using a partitioning based on a modification of a constraint on partitioning that is associated with a pipeline configuration for reconstruction of the coding unit, where the modification is based on an information dependency between two or more pipeline units associated with the pipeline configuration, and encoding or decoding the video information based on the partitioning.