Abstract: In an image decoding device according to the present invention, a circuit (241/242): derives motion information for a geometric partitioning mode to generate a motion compensation sample; and derives an intra prediction mode for the geometric partitioning mode to generate an intra-predicted sample; and a buffer (244) stores or outputs prediction information including motion information or an intra prediction mode of a block to be decoded to which the geometric partitioning mode is applied and a prediction type with which whether inter prediction or intra prediction has been applied can be determined.

Abstract: An image decoding device includes a decoding unit configured to decode a first syntax for controlling possibility of application of a geometric partitioning mode of a decoding target sequence, and to control whether to decode a second syntax for controlling possibility of application of an intra prediction mode to the geometric partitioning mode of the decoding target sequence according to a value of the first syntax.

Abstract: 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.

Abstract: An image decoding device (200) includes: an inverse transform unit (220B/220C) configured to generate a prediction residual signal by inverse transform, the inverse transform unit (220B/220C) 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.

Abstract: An image decoding device (200) includes: a merge unit (241A2) configured to apply geometric block partitioning merge to a target block divided in a rectangular shape, wherein the merge unit (241A2) includes: a merge mode specifying unit (241A21) configured to specify whether or not the geometric block partitioning merge is applied; a geometric block partitioning unit (241A22) configured to specify a geometric block partitioning pattern and further perform geometric block partitioning on the target block divided in the rectangular shape by using the specified geometric block partitioning pattern; and a merge list construction unit (241A23) configured to construct a merge list for the target block subjected to the geometric block partitioning and decode motion information.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: An image decoding device includes a circuit that generates a prediction signal included in a prediction block based on a reference signal included in a reference block. The circuit includes an interpolation filter that generates an interpolation signal of a decimal reference pixel included in the reference block from a reference signal of an integer reference pixel included in the reference block. The circuit selects a type of the interpolation filter based on a block size of the prediction block and a quantization parameter of the prediction block.

Abstract: 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.