Panasonic Intellectual Property Corporation of America

Che Wei Kuo

Takahiro Nishi

Tadamasa Toma

Kiyofumi Abe

Chong Soon Lim

Hai Wei Sun

Han Boon Teo

Jing Ya Li

Yusuke Kato

Chu Tong Wang

Ru Ling Liao

An encoder includes circuitry and memory. The circuitry, in operation, generates a first coefficient value by applying a CCALF (cross component adaptive loop filtering) process to a first reconstructed image sample of a luma component. The circuitry generates a second coefficient value by applying an ALF (adaptive loop filtering) process to a second reconstructed image sample of a chroma component. The circuitry generates a third coefficient value by adding the first coefficient value to the second coefficient value, and encodes a third reconstructed image sample of the chroma component using the third coefficient value. In the CCALF process, in response to a coordinate of the second reconstructed image sample being (x, y), coordinates of the first reconstructed image samples are (2x, 2y−1), (2x−1, 2y), (2x, 2y), (2x+1, 2y), (2x−1, 2y+1), (2x, 2y+1), (2x+1, 2y+1), and (2x, 2y+2).

System and method for video coding

An encoder that encodes a current block to be encoded in an image is provided. The encoder includes: processor; and memory coupled to the processor, in which, in operation, the processor: generates a first prediction image based on a motion vector, the first prediction image being an image with full-pel precision; generates a second prediction image using an interpolation filter by interpolating a value at a fractional-pel position between full-pel positions included in the first prediction image; and encodes the current block based on the second prediction image, and in the using of the interpolation filter, the interpolation filter is switched between a first interpolation filter and a second interpolation filter differing in a total number of taps from the first interpolation filter.

Method of transmitting a bitstream including an encoded signal and syntax information to which a decoder performs a decoding method of decoding a current block based on a prediction image generated using an interpolation filter

An image encoder is provided including circuitry and a memory coupled to the circuitry. The circuitry, in operation, responds to a size of a block satisfying a size condition by generating a prediction image using a prediction mode selected from a plurality of prediction modes. The plurality of prediction modes include a first prediction mode in which a prediction process uses a motion vector and a reference block in a same picture as the block. The circuitry encodes the block using the prediction image.

Image encoder, image decoder, image encoding method, and image decoding method

Provided is an encoder includes: circuitry; and memory coupled to the circuitry, in which in operation, the circuitry: generates a prediction image of a current block to be processed, using a first motion vector; and updates a history based motion vector predictor (HMVP) table using a first candidate having the first motion vector, the HMVP table storing, in a first in first out (FIFO) method, a plurality of second candidates each having a second motion vector used for a processed block, and in the updating of the HMVP table, the circuitry: determines whether a size of the current block is less than or equal to a threshold size; and skips the updating of the HMVP table when the size of the current block is determined to be less than or equal to the threshold size.

Encoder, decoder, encoding method, and decoding method

An encoder determines, based on a width and a height of a block, whether or not to disable a prediction mode in which the block is split along a partitioning line defined by a distance and an angle and then prediction is performed; and encodes the block with the prediction mode disabled or not disabled according to a result of the determination on whether or not to disable the prediction mode. Here, the distance is the shortest distance between the center of the block and the partitioning line, and the angle is an angle representing a direction from the center of the block toward the partitioning line in the shortest distance. The encoder determines to disable the prediction mode when (i) a width-to-height ratio is at least 8 or (ii) a height-to-width ratio is at least 8.

Encoding and decoding with merge mode and block partition index

An image encoder includes: circuitry; and a memory coupled to the circuitry. The circuitry, in operation: calculates first values of a current block using intra prediction, the intra prediction being limited to planar mode, the planar mode using multiple reference pixels for each pixel location of the current block; calculates second values of the current block using inter prediction; calculates third values of the current block by weighting the first values and the second values; and encodes the current block using the third values, and in the calculating of the third values, a first weight is applied to the first values and a second weight is applied to the second values, the second weight being different from the first weight.

Image encoder which determines whether to perform CIIP, image decoder, image encoding method, and image decoding method

An encoder includes: circuitry; and memory coupled to the circuitry. In the encoder, in operation, the circuitry: performs calculation that involves multiplication and from which a plurality of discrete integers are yieldable as a calculation result, to derive one of the plurality of discrete integers as a quantization parameter threshold; and when orthogonal transform is skipped for a current block of an image, determines a quantization parameter value for the current block, using the quantization parameter threshold. The calculation involves multiplying a first value by a first fixed value, the first value and the first fixed value being each an integer. The first value is a limit value to be included in a header of a bitstream.

Encoder that performs calculation from which a plurality of discrete integers are yieldable as a calculation result to derive one of the plurality of discrete integers as a quantization parameter threshold

An encoder includes circuitry and memory connected to the circuitry. The circuitry: derives an absolute value of a sum of horizontal gradient values; derives, as a first parameter, the total sum of the absolute values of horizontal gradient values; derives, as a second parameter, the total sum of the absolute values of vertical gradient values; derives a horizontal-related pixel difference value; derives, as a third parameter, the total sum of the absolute values of horizontal-related pixel difference values; derives a vertical-related pixel difference value; derives, as a fourth parameter, the total sum of the absolute values of vertical-related pixel difference values; and generates a prediction image using the first to fourth parameters.

An encoder includes circuitry and memory coupled to the circuitry. The circuitry, in operation: determines whether a size of a current block, which is a unit for which a vector candidate list including vector candidates is generated, is less than or equal to a threshold; when the size of the current block is less than or equal to the threshold, generates the vector candidate list by registering a history-based motion vector predictor (HMVP) vector candidate in the vector candidate list from an HMVP table without performing a first pruning process; when the size of the current block is greater than the threshold, generates the vector candidate list by performing the first pruning process and registering the HMVP vector candidate in the vector candidate list from the HMVP table; and encodes the current block using the vector candidate list.

An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry writes, into a bitstream, a first flag indicating whether or not to enable a first process of applying a filter to a first image to generate a second image, holding the second image as a reference image, and displaying the second image. When the first process is not enabled, circuitry writes, into the bitstream, one or more parameters for controlling a second process of applying the filter to the first image to generate the second image, holding the first image as a reference image, and displaying the second image.

An encoder includes circuitry and memory coupled to the circuitry. The circuitry, in operation, determines whether a first block is available and whether a second block is available, the first block and the second block being defined relative to a current block to be processed; selects a context model based on whether the first block is available, whether the second block is available, which of inter prediction and intra prediction is to be applied to the first block, and which of inter prediction and intra prediction is to be applied to the second block; and encodes, using the context model selected, a parameter indicating which of intra prediction and inter prediction is to be applied to the current block.

Encoder and decoder that selects a context model based on availability of blocks and prediction mode to be applied to the blocks

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.

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Singapore, Singapore

Che Wei Kuo