Kddi Corporation

Yoshitaka Kidani

Kei Kawamura

Sei Naito

Kyohei Unno

Haruhisa Kato

An image decoding device according to the present invention includes a circuit, wherein the circuit controls decoding of syntax that specifies whether or not merge with motion vector difference is applied to a partitioned region 0, which is partitioned in a geometric partitioning mode of a decoding target block, in accordance with a value of syntax that specifies whether or not a prediction mode of the partitioned region 0 is an intra prediction mode.

Image decoding device, image decoding method, and program

An image decoding device includes a circuit which executes a first process that derives motion information for a geometric partitioning mode to generate a motion compensation sample, and a second process that derives an intra prediction mode for the geometric partitioning mode to generate an intra predicted sample. The first process determines that the motion information can be derived based on bi-prediction from an application area to which inter prediction is applied, in a case where a coding block is included in a B slice, intra prediction is applied to one partitioned area partitioned by the geometric partitioning mode applied to the coding block, and the inter prediction is applied to another partitioned area.

An image decoding device includes: a prediction signal generation unit that generates a prediction signal by intra prediction, wherein in a block to which intra sub-partitions are applied, the prediction signal generation unit refers to a pixel of a decoded block adjacent to the block when generating prediction signals of all sub-blocks in the block.

An image decoding device includes an inverse transform unit configured to generate a prediction residual signal by inverse transform, the inverse transform unit is configured to control a method of decoding a secondary transform index of a target block according to information indicating a position where a non-zero coefficient is generated in the target block.

An image decoding device according to the present invention including a decoding unit configured to decode first syntax that controls transmission precision of a merge with motion vector difference in a sequence of a decoding target, wherein the value of the first syntax being '1' specifies that both fractional precision and integer precision could be used as the transmission precision of the merge with motion vector difference in the sequence of the decoding target, and the value of the first syntax being “0” specifies that the first syntax uses fractional precision as the transmission precision of a merge with motion vector difference in the sequence of the decoding target.

An image decoding device includes: a motion compensation predictor configured to generate a prediction image signal of a prediction target block based on information about a motion vector in a unit of the block and a reference frame; an overlapped block motion compensator carrying out an overlapped block motion compensation process of correcting the prediction image signal of the prediction target block by subjecting the prediction image signal of the prediction target block and a prediction image signal generated based on information about a motion vector and a reference frame of an adjacent block of the prediction target block to weighted averaging; and a determinator determining whether the overlapped block motion compensation process is applied to the prediction target block or not. The determinator determines application of the overlapped block motion compensation process to the prediction target block, when unidirectional prediction is applied to the adjacent block.

Image decoding device with block motion compensator and determination mechanism

An image decoding device includes: a motion compensation predictor configured to generate a prediction image signal of a prediction target block based on information about a motion vector in a unit of the block and a reference frame; an overlapped block motion compensator carrying out an overlapped block motion compensation process of correcting the prediction image signal of the prediction target block by subjecting the prediction image signal of the prediction target block and a prediction image signal generated based on information about a motion vector and a reference frame of an adjacent block of the prediction target block to weighted averaging; and a determinater determining whether the overlapped block motion compensation process is applied to the prediction target block or not. The determinater determines application of the overlapped block motion compensation process to the prediction target block, when unidirectional prediction is applied to the adjacent block.

A decoding-side first generation unit generating, for a target unit, a first component prediction sample. A decoding-side linear prediction unit using the first component sample and a prediction coefficient to generate a linear prediction sample of a second component. A decoding-side second generation unit using the second component linear prediction sample to generate, for the target unit, a second component prediction sample. The decoding-side linear prediction unit uses a first coefficient as the prediction coefficient when the first component sample is equal to or below a threshold value, and uses a second coefficient, different from the first, as the prediction coefficient when the first component sample is greater than the threshold value. The threshold value is set on a parameter representing a distribution or change in a reference sample of the first component and/or the second component contained in a reference unit referenced for the target unit.

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Fujimino, Japan

Yoshitaka Kidani