Abstract: A method and apparatus to improve compression efficiency in a video compression scheme enables flexible use of local illumination compensation. Such methods comprise individual local illumination compensation for components of a video block. Such methods also comprise flexible derivation methods for illumination compensation information. In one embodiment, local illumination compensation information can be inherited from other others, such as neighboring blocks.

Abstract: Significance flags in advanced video compression systems are coded using contexts adaptive to the last N significance flags coded taken in a scanning order. One embodiment uses the last N significance flags in scanning order as a predictor to determine which of a plurality of sets of significance flag contexts to use for coding subsequent significance flags. A second embodiment uses the last N significance flags in scanning order as a predictor in order to modulate the probability value associated with significance flag contexts that are used to code significance flags for future coding.

Abstract: A method for encoding a picture block is disclosed. A predictor is determined as a weighted sum of sample values of a first motion compensated reference block in a first reference image and of a second motion compensated reference block in a second reference image. Then, a residual block determined from the picture block and the predictor is encoded in a bitstream. Advantageously, the weights of the weighted sum are determined by minimizing an error between reconstructed samples neighboring the picture block and samples neighboring the first and second reference blocks.

Abstract: Encoders and decoders of digital video signals use combined intra prediction modes for some images. In at least one embodiment, combined intra prediction modes can result from the intra prediction modes of neighboring blocks. The combined intra prediction mode can be added to a most probable modes list. Various embodiments describe techniques for combining the intra prediction modes, comprising a combination of reference samples and a combination of directions to form a prediction. Another embodiment adds a combination mode to the most probable modes list if the two modes that are combined to form it are directional modes with angle difference less than 90 degrees. Another embodiment uses a linear combination of intra prediction modes and another embodiment performs a linear combination which depends on the distance of a prediction from the left and above blocs.

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 coefficients 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: Methods (800, 900, 1600, 1700) and apparatuses (2100) for signaling decoding data in a video bitstream, wherein one uses a syntax element indicating whether the decoding data are explicitly coded in the video bitstream or inferred from previous data of the video bitstream. A bitstream, a computer-readable storage medium and a computer program product are also described.

Abstract: Methods and apparatuses for video coding and decoding are provided. The method includes deriving one or more illumination compensation parameters based on neighboring samples of a sub-block of a block and neighboring samples of a motion-compensated reference sub-block; deriving a prediction sub-block by applying on the motion-compensated reference sub-block an illumination compensation using the one or more derived illumination compensation parameters. A computer-readable storage medium and a computer program product are also described.

Abstract: A video codec can involve determining a motion compensation mode associated with encoding a first block of picture information, the motion compensation mode including a sub-block based motion compensation prediction mode or a non-rectangular block partition mode; determining that a second block of picture information spatially neighboring the first block was encoded or decoded based on an illumination compensation; and encoding or decoding the first block based on the motion compensation mode and the illumination compensation.

Abstract: A method and apparatus to improve compression efficiency in a video compression scheme enables use of switchable interpolation filters. The interpolation filters are used on multiple partitions of video blocks, enabling better motion compensated prediction and improved video coding efficiency. In one embodiment, an interpolation filter index is derived for triangle partitions of a block from motion information candidate parameters, so that each unidirectional motion compensation can use a different value of interpolation filter index. In another embodiment, an interpolation filter index is a function of characteristics, such as shape or area, of video partitions.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding based on linear weighted intra prediction, also called matrix based intra prediction, are presented. Accordingly, the encoding or decoding comprises obtaining intra predicted samples of a block from a selected weight matrix and associated bias and from a set of neighboring reference samples; wherein any coefficient of the selected weight matrix is a power of two. According to relaxed version, not all but only a part of the coefficients of the selected weight matrix is a power of two. Advantageously, such arrangement allows to reduce the amount of memory for storing data and to reduce the complexity of the intra prediction samples computation.

Abstract: Methods and apparatuses for video coding and decoding are provided. The method of video encoding includes accessing a bin of a syntax element associated with a block in a picture of a video, determining a context for the bin of the syntax element associated with the syntax element and entropy encoding the bin of the syntax element based on the determined context wherein either the bin of the syntax element is based on the relevance of a prediction by a neural network of the syntax element or the probability associated to the context is determined by a neural network. A bitstream formatted to include encoded data, a computer-readable storage medium and a computer-readable program product are also described.

Abstract: Video processing such as encoding and/or decoding a picture can involve deriving an inter-prediction parameter based on first and second merge candidates used to generate a pairwise merge candidate, wherein the inter-prediction parameter comprises at least one of an index for weighted bi-prediction or an interpolation filter index; and encoding at least a portion of the picture information based on the inter-prediction parameter.

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: A method includes encoding target parameters describing characteristics for a target color space for a video picture to be displayed in the target color space and encoding color transform parameters that facilitate remapping the video picture to the target color space. A method includes decoding target parameters describing characteristics for a target color space for a video picture to be displayed in the target color space, decoding color transform parameters that facilitate remapping the video picture to the target color space, remapping the video picture to the target color space utilizing at least one of the decoded color transform parameters, and displaying the remapped video picture in the target color space. The color transform parameters represent at least three successively applied color transforms comprising a first color transform followed by a second color transform followed by a third color transform. Related apparatus for each method are described.

Abstract: A method for reconstructing a picture block is disclosed, wherein the block is predicted using local illumination compensation. The parameters of local illumination compensation are determined according to a selection of reconstructed samples located to the left and above of the current block. In the case where some of them are unavailable, they may be replaced using different techniques.

Abstract: Different implementations are described, particularly implementations for video encoding and decoding based on a linear model responsive to neighboring samples are presented. Accordingly, for a block being encoded or decoded in a picture, refined linear model parameters are determined for a current subblock in the block and for encoding the block, the local illumination compensation uses a linear model for the current subblock based on the refined linear model parameters. In a first embodiment, the number N of reconstructed samples increases with the available data for the subblock. In a second embodiment, partial linear model parameters are determined for the subblock and refined linear model parameters are derived from a weighted sums of partial linear model parameters. In a third embodiment, the subblocks are independently LIC processed.

Abstract: In at least one embodiment, a method and apparatus for encoding/decoding a picture comprising predicting at least one block, wherein the predicting comprises performing motion compensation and local illumination compensation based on a reference block, the local illumination compensation including applying a linear model based on sums of absolute differences of neighboring reconstructed samples and corresponding reference samples of the reference block, wherein the neighboring reconstructed samples and corresponding reference samples of the reference block are co-located according to an L-shape substantially adjacent to the block to be predicted, the L-shape comprising a row of pixels located to the top side of the predicted block and a column of pixels located to the left side of the predicted block, the co-location being determined according a motion vector of the predicted block.

Abstract: A method for video decoding is disclosed. A first reconstructed version of an image block of an encoded video is accessed. The first reconstructed version of said image block is filtered by a first neural network to form a second reconstructed version of said image block to be used as reference. The second reconstructed version of said image block is filtered by a second neural network to form a third reconstructed version of said image block to be displayed. The first and second neural networks are trained jointly.

Abstract: Methods and apparatuses for video coding and decoding are provided. The method of video encoding includes accessing a bin of a syntax element associated with a block in a picture of a video, determining a context for the bin of the syntax element associated with the syntax element and entropy encoding the bin of the syntax element based on the determined context wherein either the bin of the syntax element is based on the relevance of a prediction by a neural network of the syntax element or the probability associated to the context is determined by a neural network. A bitstream formatted to include encoded data, a computer-readable storage medium and a computer-readable program product are also described.

Abstract: The present principles relate to a method and device for context-adaptive binary arithmetic coding a sequence of binary symbols representing a syntax element related to video data or a syntax element relative to a video data.