Abstract: An encoder includes: circuitry; and memory coupled to the circuitry. In operation, the circuitry: derives a base motion vector to be used in predicting a current block to be encoded; derives a first motion vector different from the base motion vector; derives a motion vector difference based on a difference between the base motion vector and the first motion vector; determines whether the motion vector difference is greater than a threshold; modifies the first motion vector when the motion vector difference is determined to be greater than the threshold, and does not modify the first motion vector when the motion vector difference is determined not to be greater than the threshold; and encodes the current block using the first motion vector modified or the first motion vector not modified.

Abstract: An encoder capable of properly handling an image to be encoded or decoded includes processing circuitry and memory connected to the processing circuitry. Using the memory, the processing circuitry: obtains parameters including at least one of (i) one or more parameters related to a first process for correcting distortion in an image captured with a wide angle lens and (ii) one or more parameters related to a second process for stitching a plurality of images; generates an encoded image by encoding a current image to be processed that is based on the image or the plurality of images; and writes the parameters into a bitstream including the encoded image.

Abstract: The present disclosure provides a video data processing method for cross-component sample adaptive offset (CCSAO). The method includes determining an index based on a vertical coordinate of a chroma sample within a picture; determining a luma sample based on the index; classifying the chroma sample based on a reconstructed value associated with the luma sample; determining an offset based on the classification; and adding the offset to a reconstructed value associated with the chroma sample.

Abstract: During video encoding or decoding, cross-component prediction can be used to predict a chroma sample from collocated reconstructed luma samples. The prediction can be based on a gradient of the collocated reconstructed luma samples, a down-sampled value of the collocated reconstructed luma samples, or a combination thereof. An exemplary method includes: determining a first value associated with a chroma sample, by applying a first gradient pattern to reconstructed values of a first plurality of luma samples; determining a second value associated with the chroma sample, by applying a down-sampling filter to reconstructed values of a second plurality of luma samples; and predicting the chroma sample based on the first value and the second value.

Abstract: An encoder includes circuitry and memory connected to the circuitry. The circuitry: derives an absolute value of a sum of gradient values in first and second ranges; derives, as a first parameter, a total sum of absolute values of sums of gradient values derived respectively for pairs of relative pixel positions; derives a pixel difference value between pixel values in the first and second ranges; inverts or maintains a plus or minus sign of the pixel difference value, according to a plus or minus sign of the sum of the gradient values indicating the sum of the gradient values in the first and second ranges; derives, as a second parameter, a total sum of pixel difference values each having the plus or minus sign inverted or maintained, the pixel difference values derived respectively for the relative pixel positions; and generates a prediction image using the first and second parameters.

Abstract: An encoder according to one aspect of the present disclosure encodes a block of an image, and includes a processor and memory connected to the processor. Using the memory, the processor partitions a block into a plurality of sub blocks and encodes a sub block included in the plurality of sub blocks in an encoding process including at least a transform process or a prediction process. The block is partitioned using a multiple partition including at least three odd-numbered child nodes and each of a width and a height of each of the plurality of sub blocks is a power of two.

Abstract: The present disclosure provides methods for performing simplified matrix weighted intra prediction. The method can include: determining a classification of a target block; and generating, based on the classification, a matrix-weighted intra prediction (MIP) signal, wherein determining the classification of the target block comprises: in response to the target block having a size of 4×4, determining that the target block belongs to a first class; or in response to the target block having a size of 8×8, 4×N or N×4, N being an integer between 8 and 64, determining that the target block belongs to a second class.

Abstract: Provided is an encoder which includes circuitry and memory. The circuitry encodes an image block using the memory. In encoding the image block, the circuitry: obtains one or more size parameters related to a size of the image block; determines whether the one or more size parameters and one or more thresholds satisfy a determined relationship; encodes a split parameter when the one or more size parameters and the one or more thresholds are determined to satisfy the determined relationship, the split parameter indicating whether the image block is to be split into a plurality of partitions including a non-rectangular partition; and encodes the image block after splitting the image block into the plurality of partitions when the split parameter indicates that the image block is to be split into the plurality of partitions.

Abstract: Provided is an encoder which includes circuitry and memory. Using the memory, the circuitry splits an image block into a plurality of partitions, obtains a prediction image for a partition, and encodes the image block using the prediction image. When the partition is not a non-rectangular partition, the circuitry obtains (i) a first prediction image for the partition, (ii) a gradient image for the first prediction image, and (iii) a second prediction image as the prediction image using the first prediction image and the gradient image. When the partition is a non-rectangular partition, the circuitry obtains the first prediction image as the prediction image without using the gradient image.

Abstract: An encoder according to one aspect of the present disclosure encodes a block of an image, and includes a processor and memory connected to the processor. Using the memory, the processor partitions a block into a plurality of sub blocks and encodes a sub block included in the plurality of sub blocks in an encoding process including at least a transform process or a prediction process. The block is partitioned using a multiple partition including at least three odd-numbered child nodes and each of a width and a height of each of the plurality of sub blocks is a power of two.

Abstract: A method for video data processing includes: determining a category index of a target chroma sample, wherein the category index is determined based on a first reconstructed value associated with a co-located luma sample and a second reconstructed value associated with the target chroma sample; determining an offset based on the category index; and adding the offset to a third reconstructed value associated with the target chroma sample.

Abstract: An image encoder includes circuitry and a memory, wherein the circuitry, in operation, determines whether inter prediction is to be applied to a current block; in response to determining that the inter prediction is to be applied to the current block, performs a partition prediction process; and, in response to determining that the inter prediction is not to be applied, encodes the current block without using the partition prediction process. The partition prediction process includes predicting first values of a set of pixels between a first partition and a second partition in the current block, using a first motion vector for the first partition; predicting second values of the set of pixels, using a second motion vector for the second partition; weighting the first values and the second values; and generating a prediction image for the current block using the weighted first values and the weighted second values.

Abstract: An encoder includes circuitry and a memory coupled to the circuitry, wherein the circuitry, in operation, performs a partition process. The partition process includes calculating first values of a set of pixels between a first partition and a second partition in a current block, using a first motion vector for the first partition; calculating second values of the set of pixels, using a second motion vector for the second partition; and calculating third values of the set of pixels by weighting the first values and the second values. When a ratio of a width to a height of the current block is larger than 4 or a ratio of the height to the width of the current block is larger than 4, the circuitry disables the partition process.

Abstract: An image encoder or decoder includes circuitry and a memory coupled to the circuitry. The circuitry, in operation, predicts a first set of samples for a first partition of a current picture with one or more motion vectors including a first motion vector and predicts a second set of samples for a first portion of the first partition with one or more motion vectors from a second partition different from the first partition. The samples of the first set of samples of the first portion of the first partition and of the second set of samples of the first portion of the first partition are weighted. A motion vector for the first portion of the first partition is stored which is based on one or both of the first motion vector and the second motion vector. The first partition is encoded or decoded using at least the weighted samples of the first portion of the first partition.

Abstract: The present disclosure provides methods for processing video content. One exemplary method comprises: receiving a bitstream comprising coded video data; determining a first parameter of a coding block; determining, according to the first parameter, one or more second parameters associated with a delta quantization parameter (QP) value or a chroma QP offset value; and determining, according to the one or more second parameters, at least one of the delta QP value or the chroma QP offset value.

Abstract: The present disclosure provides systems and methods for processing video content. The method can include: receiving data representing a first block and a second block in a picture, the data comprising a plurality of chroma samples associated with the first block and a plurality of luma samples associated with the second block; determining an average value of the plurality of luma samples associated with the second block; determining a chroma scaling factor for the first block based on the average value; and processing the plurality of chroma samples associated with the first block using the chroma scaling factor.

Abstract: An encoder includes circuitry and memory connected to the circuitry. In operation, the circuitry corrects a base motion vector using a correction value in a fixed direction; and encodes a current partition by using the corrected base motion vector corrected. The correction value is specified by an index indicating one of correction values included in a table. The table is selected from among a plurality of tables, wherein the correction values in one of the plurality of tables have different increments from the correction values in another one of the plurality of tables.

Abstract: Provided is an encoder including circuitry and memory coupled to the circuitry. A prediction mode for a current block is an affine mode, and in operation, the circuitry: derives a base motion vector which is a motion vector to be used in a prediction process for the current block, and is a motion vector at an affine-mode control point in the current block; derives a first motion vector different from the base motion vector; derives a motion vector difference based on a difference between the base motion vector and the first motion vector; determines whether the motion vector difference is greater than a threshold; if so, modifies a second motion vector different from the base motion vector and the first motion vector, and if not, does not modify the second motion vector; and encodes the current block using the second motion vector modified or the second motion vector not modified.

Abstract: The present disclosure provides a computer-implemented method for encoding video. The method includes: determining whether a coded video sequence (CVS) contains equal number of profile, tier and level (PTL) syntax structures and output layer sets (OLSs); and in response to the CVS containing equal number of PTL syntax structures and OLSs, coding the bitstream without signaling a first PTL syntax element specifying an index, to a list of PTL syntax structures in the VPS, of a PTL syntax structure that applies to a corresponding OLS in the VPS.

Abstract: The present disclosure provides method and apparatus for motion field storage in video coding. An exemplary method includes: determining whether a first uni-prediction motion vector for a first partition of a block and a second uni-prediction motion vector for a second partition of the block are from a same reference picture list; and in response to the first uni-prediction motion vector and the second uni-prediction motion vector being determined to be from the same reference picture list, storing, in a motion field of the block, one of the first uni-prediction motion vector and the second uni-prediction motion vector for a subblock located in a bi-predicted area of the block.