Abstract: A block of video data is split and coded using existing transform sizes through one of several embodiments. In one embodiment, the block is split in alternate dimensions, depending on the block size. In another embodiment, the video block can be coded after splitting the block into at least two rectangular sub-blocks using horizontal or vertical divisions. Successive divisions using asymmetric splitting are forbidden if an equivalent split can be attained using only symmetrical splitting, and only one succession of divisions is permitted when there are other successions of asymmetric splitting that result in the identical sub-blocks. In another embodiment, a video block is split using successive splits, but the second type of split is dependent on the first type of split. Methods, apparatus, and signal embodiments are provided for encoding and decoding.

Abstract: A decoding method for decoding an image is disclosed. The decoding method comprises for at least one slice of the image: —decoding (S210) the slice from a bitstream; —determining (S230) information representative of a size of a region of the decoded slice, the size being different from a size of a basic coding block used for decoding the slice; and —filtering (S240) the decoded slice by applying a filter on the region identified by the determined information.

Abstract: A Frame Rate Up-Conversion (FRUC) derivation process, based on frame rate up-conversion techniques, is developed in the reference software JEM (Joint Exploration Model) by the Joint Video Exploration Team (JVET). In one embodiment, a modified FRUC derivation process improves the performance of the current FRUC tool is provided. For example, an initial list of motion vector candidates defined in the FRUC derivation process may be reordered, and/or one or more of the ordered motion vector candidates in the defined list may be removed to improve the efficiency of the process. The reordering and/or the removal may be based on, e.g., one or more of previously determined motion vector candidates of one or more previously decoded blocks. In addition, the adaptive reordering mode may be signaled by the encoder to the decoder as part of the modified FRUC derivation process.

Abstract: A method for coding an HDR picture is disclosed that includes mapping the HDR picture to obtain a SDR picture, determining color correcting parameters, color correcting said SDR picture responsive to said color correcting parameters, and encoding the color corrected SDR picture in a stream. In the method, determining color correcting parameters includes determining an intermediate SDR picture so that at least one color appearance value is preserved between said HDR picture and said intermediate SDR picture, and determining the color correcting parameters from said intermediate SDR picture and from said SDR picture.

Abstract: A method for decoding a current block of a picture is disclosed that comprises: decoding (S120) a plurality of reference blocks; filtering (S130) with a deblocking filter along edges of said plurality of reference blocks; and decoding (S140) said current block by intra prediction from said plurality of filtered reference blocks.

Abstract: Method and apparatus for encoding and decoding a video. A method and an apparatus for encoding a video are disclosed. Such a method comprises, for at least one block having a size N which is not a power of 2 along at least one dimension: —determining (40) a predicted block for said at least one block, —obtaining (41) a residual block from said at least one block and said predicted block, —performing (42) block transform of said residual block, said residual block having a size N, —encoding (43) said transformed residual block. Corresponding method and apparatus for decoding a video are also disclosed.

Abstract: The method for intra frame prediction allows for the recovery of some intra directional modes that are otherwise rendered useless due to the classical padding process. Directional modes are recovered by filling pixel locations in the prediction unit with samples from the portion of the unit that is determined to have samples available for use using a counterpart directional mode to the one that is useless. When it is determined that reference samples are missing for a particular prediction unit or portion thereof given a particular directional mode, a determination is made about whether reference samples along another portion of the prediction unit are available. The other portion is the side of the prediction unit at an opposite end of the particular directional mode.

Abstract: In a particular implementation, a video decoder may decode an initial motion vector predictor from the bitstream for a current block, and perform motion search in a small search window to refine the initial motion vector predictor. The initial motion vector may be rounded before being refined. The motion refinement can be based on a discontinuity measure between pixels of a current block and pixels of adjacent block, and can also be based on gradients between the current block and adjacent blocks. The motion vector for the current block is then decoded based on the refined motion vector predictor, and the motion vector difference if there is any. The motion refinement can also be performed on the motion vector for the current block directly. Through motion refinement, the decoder may increase the motion resolution. A corresponding video encoder may choose whether to use motion refinement based on encoder decisions.

Abstract: A decoding method for decoding a block of an image is disclosed that comprises:—determining a split mode for said block in a set of split modes;—splitting said block into at least two sub-blocks responsive to said split mode;—decoding each of the at least two sub-blocks; wherein said set of split modes comprises at least one split mode for asymmetrically splitting said block into the at least two sub-blocks.

Abstract: A method for video encoding and corresponding apparatus are disclosed. For at least one current block of a picture, at least one motion vector predictor for said current block is adjusted, based on a relation between a first format in which the picture is represented and a second format in which the picture is to be rendered, and the current block is encoded using the adjusted motion vector predictor. Corresponding method and apparatus for video decoding are also disclosed.

Abstract: A method and an apparatus for encoding an immersive video are disclosed. For at least one block of a picture of said video, a parameter for quantizing is determined according to a spatial position of said block in said picture, and used for encoding said block. A corresponding decoding method and decoding apparatus are also disclosed.

Abstract: Sample Adaptive Offset (SAO) can be used for artifact reduction in video coding. Designing the categories in SAO based on sample statistics may improve the SAO efficiency. In one embodiment, the categories for BO or EO can be initially determined, for example, as specified in HEVC. For the categories that are determined to have non-zero offsets, the category with the highest number of samples may be divided into two sub-categories and an offset is encoded for each of the sub-categories. In addition, the category with the least number of samples may use a zero offset. In another embodiment, the initial categories can be homogenized to form new categories such that each new category has substantially the same number of samples. A histogram based on the number of samples or the number of gradient-based values can be used for adjusting the categories for BO or EO, respectively.

Abstract: Binary tree split mode coding is performed while encoding digital video image blocks using a quad tree plus binary tree coding. The quadtree split can be represented by some combinations of horizontal and vertical binary tree split. Blocks are constrained to be split down to a minimum block size and with certain split constraints such that some redundant tree structures are avoided. Redundant syntax in coding the binary tree split mode syntax element is removed to provide coding efficiency.

Abstract: In a particular implementation, a video decoder may refine an initial motion vector predictor decoded from the bitstream for a current block. In order to reduce signaling overhead, the decoder may determine whether or not motion refinement is used based on information that is already available, for example, based on whether the motion field is uniform around the current block, and whether there is a certain level of textureness in adjacent blocks. The motion vector difference decoded from the bitstream can be used to automatically activate or deactivate the motion refinement without receiving explicit signaling in the bitstream. For example, when the motion vector difference is smaller than a threshold, motion refinement is automatically activated, and when the motion vector difference is greater than another threshold, motion refinement is automatically deactivated. A corresponding video encoder may choose whether to use and signal motion refinement based on encoder decisions.

Abstract: A decoding method is disclosed that comprises:—decoding (S120) a block of a picture, said block being intra predicted from a plurality of reference blocks;—determining (S130) a frontier inside the decoded block based on a frontier existing between said plurality of reference blocks; and—filtering (S140) with a de-artifacting filter along the frontier determined inside the decoded block.

Abstract: A decoding method is disclosed that comprises: decoding at least one image block from a bitstream; decoding a plurality of band offsets of a sample adaptive offset filter (SAO) and a band position of the first band offset from the bitstream; filtering the decoded block with the sample adaptive offset filter responsive to the decoded plurality of band offsets and to the decoded band position; wherein the first decoded band offset of the plurality of band offsets is necessarily a non-zero band offset.

Abstract: The present principles relates to a method for intra-predictive encoding a coding unit comprising picture data, said intra-predictive encoding depending on a prediction tree and a transform tree, characterized in that the method further comprises: —obtaining said prediction tree by spatially partitioning the coding unit according to a non-square partition type; —determining said transform tree from said coding unit in order that each of its leaves is embedded into a unique unit of said obtained prediction tree; and —signaling in a signal the size of the leaves of said transform tree and said a non-square partition type.

Abstract: It is provided an apparatus for encoding an image frame, wherein the image frame being partitioned into non-overlapping units (1002, 1008), the partitioned units being included in a first region, a second region and a third region of the image frame(1008, 1012), each of the first region, the second region and the third region being associated with an indicator indicating a raster scanning order; comprising means for encoding the third region of the image frame, based on the indicator of the third region, starting at a first unit from the right and the top in the third region using a raster scan technique (1002, 1008, 1012, 1016); means for encoding the second region of the image frame, based on the indicator of the second region, starting at a first unit from the right in the second region (1002, 1008, 1012, 016); and means for encoding the first region, based on the indicator of the first region, starting at a first unit from the top or the bottom in the first region (1002, 1008, 1012, 1016).

Abstract: Method and apparatus for intra prediction in video encoding and decoding A method and an apparatus for video encoding and decoding, and more particularly, a method and an apparatus for performing intra prediction using reference sample portion having a thickness of at least two pixels and intra prediction modes based on such reference sample portion The intra-prediction mode may specify a direction and a propagation model for determining the manner of propagating samples in the prediction block. Using a reference sample portion having a thickness of at least two pixels allows the variations in the pixel values to be used in propagating the samples in the prediction block.

Abstract: The present principles relates to a method and device for tone-mapping an input picture by using a parametric tone-adjustment function. The method is characterized in that the method comprises determining at least one parameter of said tone-adjustment function modulated by a brightness level of the input picture.