Abstract: A method of performing motion vector prediction for coding video data is disclosed. A full precision motion vector mv is determined for generating a prediction for video block in a first picture. A rounded motion vector rmv having a less precision than the full precision motion vector mv is stored. A motion vector predictor candidate is generated for a video block in a second picture from the stored motion vector.

Abstract: In some embodiments, a decoder may receive, in a bit stream and for a block of samples, a residual and an indication of a downscaling. The decoder may determine reference samples for intra prediction of the block of samples. The decoder may generate, for an intra prediction mode, a prediction of the block of samples from the reference samples, The decoder may generate a first decoded block of samples based on: the prediction of the block of samples; and the residual. Based on the indication of the downscaling, the decoder may upscale the first decoded block of samples to a second decoded block of samples.

Abstract: Disclosed are an inter-prediction method and an image decoding apparatus using the same. According to an embodiment of the present invention, there is provided an inter-prediction method including extracting a merge candidate flag and offset information from a bitstream, selecting a merge candidate corresponding to the extracted merge candidate flag from a merge candidate list including neighboring blocks of a current block as merge candidates, deciding a motion vector of the current block by applying the offset information to a motion vector of the selected merge candidate, and generating, as a prediction block of the current block, a block indicated by the motion vector of the current block in a reference picture referenced by the selected merge candidate.

Abstract: Devices, systems and methods for encoding and decoding digital video using a look-up tables (LUTs) containing motion candidates are described. In a representative aspect, a method of video processing includes maintaining one or more tables, wherein at least one table of the one or more tables is associated with one or more entries, deriving, based on a first set of motion candidates in the at least one table, a second set of motion candidates, and performing, based on the second set of motion candidates, a conversion between a current block of a video and a bitstream representation of the video.

Abstract: A method for processing a video includes performing a determination, by a processor, that a first video block is partitioned to include a first prediction portion that is non-rectangular and non-square; adding a first motion vector (MV) prediction candidate associated with the first prediction portion to a motion candidate list associated with the first video block, wherein the first MV prediction candidate is derived from a sub-block MV prediction candidate; and performing further processing of the first video block using the motion candidate list.

Abstract: A camera configured to maintain an image in a preferred orientation when the camera is passed from one user to another is provided. The camera detects a spatial orientation of the camera in at least a first position. The camera detects a vector information generated when the camera is passed from one user to another. The camera processes the spatial orientation and vector information so as to retain the image in a preferred orientation.

Abstract: Motion vectors (MVs) are used as predictors for prediction of an image for a current coding unit (CU) within a current video frame. The MVs are from a list of motion vector candidates (MVCs), which is generated. The list includes MVs determined from a first or second pattern, each pattern specifying MVC positions. The first MV positions are within a current video frame, while the second MV positions are for a video frame different from the current frame. The MVC list is generated for a current CU with the MV positions being relative to a position of the current CU. In particular, the MVC list is generated in dependence on a size of the current CU and a size of a grid specifying a minimum distance between two MV positions. One or more MVs as specified by the MV positions of said pattern are included into the MVC list.

Abstract: An encoder which includes circuitry and memory. Using the memory, the circuitry generates a list which includes candidates for a first motion vector for a first partition. The list has a maximum list size and an order of the candidates, and at least one of the maximum list size or the order of the candidates is dependent on at least one of a partition size or a partition shape of the first partition. The circuitry selects the first motion vector from the candidates included in the list; encodes an index indicating the first motion vector among the candidates in the list into the bitstream based on the maximum list size; and generates the predicted image for the first partition using the first motion vector.

Abstract: Methods, devices, and systems related to video processing are disclosed. In one example aspect, a method of video processing includes performing a conversion between a block of a current picture of a video and a coded representation of the video using an intra-subblock partitioning (ISP) mode. A prediction is determined for each sub-partition using an intra-prediction process based on samples in the current picture using the ISP mode. The block is partitioned into multiple sub-partitions including a first sub-partitions having a same top-left corner position as a top-left corner position of the block.

Abstract: A first motion vector and a second motion vector are determined for a first block in a current picture of a video, where the first motion vector is indicative of a first reference block in a first picture, and the second motion vector is indicative of a second reference block in a second picture. A bilateral template is generated based on a weighted combination of the first reference block and the second reference block. A refined first motion vector is determined based on the bilateral template and a first set of reference blocks in the first picture. A refined second motion vector is determined based on the bilateral template and a second set of reference blocks in the second picture. Prediction information of the first block is generated according to (i) the refined first motion vector, (ii) the refined second motion vector, and (iii) a final motion compensation interpolation filter.

Abstract: A method and apparatus for inter prediction. According to the position of a current block in a video picture, first motion information and second candidate motion information is determined, the motion information at least includes a motion vector; it is determined whether the distance between the motion vector of the first motion information and the motion vector of the second candidate motion information is greater than a first threshold; if the determination result is that the distance is less than or equal to the first threshold, the second candidate motion information is updated to obtain second motion information; if the determination result is that the distance is greater than the first threshold, the second candidate motion information is taken as the second motion information; and inter prediction is performed on the current block by using the first motion information and the second motion information.

Abstract: Aspects of the disclosure include methods, apparatuses, and non-transitory computer-readable storage mediums for video encoding/decoding. An apparatus includes processing circuitry that decodes a video bitstream to obtain a reduced-resolution residual block for a current block. The processing circuitry determines that a block level flag is set to a pre-defined value. The pre-defined value indicates that the current block is coded in reduced-resolution coding. Based on the block level flag, the processing circuitry generates a reduced-resolution prediction block for the current block by down-sampling a full-resolution reference block of the current block. The processing circuitry generates a reduced-resolution reconstruction block for the current block based on the reduced-resolution prediction block and the reduced-resolution residual block. The processing circuitry generates a full-resolution reconstruction block for the current block by up-sampling the reduced-resolution reconstruction block.

Abstract: A method for processing video data is provided to include: determining whether a sharing of merge list information is enabled for a merge sharing node that corresponds to an ancestor node in a coding unit split tree to allow leaf coding units of the ancestor node in the coding unit split tree to use the merge list information; and performing a conversion between a current video block of a video and a bitstream of the video based on the determining.

Abstract: A prediction image correcting device comprises a predictor (108) configured to predict a target image block obtained by dividing a present image frame by using a plurality of reference images to generate a prediction image corresponding to the target image block a prediction accuracy evaluator (109) configured to evaluate prediction accuracy of the prediction image based on a degree of similarity between the plurality of reference images used for generating the prediction image and a corrector (110) configured to perform correction processing on the prediction image by using a decoded neighboring block adjacent to the target image block, wherein the corrector is configured to control the correction processing based at least on an evaluation result of the prediction accuracy evaluator.

Abstract: Aspects of the disclosure provide methods and apparatuses for video encoding and decoding. The apparatuses include an apparatus for video decoding. Processing circuitry of the apparatus for video decoding can decode coded information for a current block from a coded video bitstream. The coded information indicates a bi-prediction motion compensation mode for the current block. The processing circuitry determines, based on current neighboring reconstructed samples of the current block, first neighboring reconstructed samples of a first prediction block, and second neighboring reconstructed samples of a second prediction block, a weight used in the bi-prediction motion compensation mode. The processing circuitry reconstructs samples in the current block based on a weighted average of corresponding samples in the first prediction block and the second prediction block using the determined weight.

Abstract: A method and apparatus of Inter prediction for video coding using a target Merge mode comprising a triangle Merge mode are disclosed. According to this method, a current block is partitioned into a first region and a second region using the target partition. A candidate list is determined. Two candidates are determined for the two regions by deriving two target candidates from the candidate list. When a selected target candidate is a uni-prediction candidate, the selected target candidate is used as one candidate; and when the selected target candidate is a bi-prediction candidate, motion information associated of the selected target candidate with List 0 or List 1 is used as one candidate. The current block or current motion information associated with the current block is encoded or decoded according to the candidate list. The candidate list is used to derive the first candidate and the second candidate.

Abstract: A prediction image correcting device comprises a predictor (108) configured to predict a target image block obtained by dividing a present image frame by using a plurality of reference images to generate a prediction image corresponding to the target image block a prediction accuracy evaluator (109) configured to evaluate prediction accuracy of the prediction image based on a degree of similarity between the plurality of reference images used for generating the prediction image and a corrector (110) configured to perform correction processing on the prediction image by using a decoded neighboring block adjacent to the target image block, wherein the corrector is configured to control the correction processing based at least on an evaluation result of the prediction accuracy evaluator.

Abstract: An image decoding method performed by a decoding apparatus according to the present disclosure comprises the steps of: decoding, on the basis of a bitstream, an affine flag that indicates whether affine prediction is applicable to a current block and a sub-block TMVP flag that indicates whether a temporal motion vector predictor based on a sub-block of the current block is usable; determining whether to decode a predetermined merge mode flag that indicates whether to apply a predetermined merge mode to the current block, on the basis of the decoded affine flag and the decoded sub-block TMVP flag; deriving prediction samples of the current block on the basis of the determining of whether to decode the predetermined merge mode flag; and generating reconstructed samples of the current block based on the prediction samples of the current block.

Abstract: Disclosed herein is a method of decoding an image including determining whether a current block is in a bi-directional optical flow (BIO) mode, calculating gradient information of prediction samples of the current block when the current block is in the BIO mode, and generating a prediction block of the current block using the calculated gradient information, wherein the calculating of the gradient information of the prediction samples of the current block includes calculating the gradient information using at least one neighbor sample adjacent to the prediction samples.

Abstract: Apparatuses and methods for Intra Sub-Partitions (ISP) are provided. The method includes: obtaining information of ISP, and determining a size of a chroma transform block (TB) of the coding unit based on SubWidthC and SubHeightC when at least a first condition is fulfilled. The first condition includes the information of ISP indicates that ISP is used for splitting the luma coding block. SubWidthC and SubHeightC are variables depending on chroma format information. The chroma format information indicates a chroma format of a picture the coding unit belongs to. The method can apply to all chroma format. The chroma format includes at least one of: 4:2:0, or 4:2:2, or 4:4:4. An accurate and versatile way to determine the size of the chroma transform block for the ISP is achieved.