Abstract: In prediction, one of a first mode for deriving, using pixels in an image including a target block, predicted pixels in the target block, a second mode for deriving the predicted pixels in the target block using pixels in an image different from the image including the target block, a third mode for generating the predicted pixels in the target block using both the pixels in the image including the target block and pixels in the different image can be used. If the third mode is used in at least one of the first and second blocks, the intensity of deblocking filter to be performed for the boundary between the first and second blocks is set to the same intensity as in a case in which the first mode is used in at least one of the first and second blocks.

Abstract: An image encoding device includes a prediction unit configured to generate prediction errors being a difference between a predicted image obtained by prediction processing for an input image and the input image, a first transform unit configured to generate first transform coefficients by performing orthogonal transform on the prediction errors, a second transform unit configured to generate second transform coefficients by performing LFNST processing on the first transform coefficients, a quantization unit configured to generate quantization coefficients by performing quantization processing on the second transform coefficients, and an encoding unit configured to encode the quantization coefficients, wherein the encoding unit encodes information indicating whether a range of possible values at least taken by the second transform coefficients is to be a range determined based on a bit depth or a fixed range.

Abstract: Control over encoding of a quantization parameter is appropriately enabled with not only square sub-blocks but also rectangular sub-blocks by using a quantization control size adaptively according to a shape of sub-blocks, with the result that coding efficiency is improved.

Abstract: An encoding apparatus comprises a quantizer quantizing transform coefficients in a block in an image using a first quantization matrix, and an encoder encoding the first quantization matrix, wherein, for encoding the first quantization matrix, if using a first mode, the encoder encodes information indicating that the first quantization matrix is the same as a second quantization matrix having already been encoded, if using a second mode, encodes a difference between an element of the first quantization matrix and an element of the second quantization matrix, and if using a third mode, encodes a difference between an element and another element within the first quantization matrix, wherein a code amount of information representing the first mode is used is less than that of information representing that the second mode is used.

Abstract: An encoding device, if it is determined that a transforming processing is applied to a block to be encoded, encodes the block using a first quantization parameter, if it is determined that the transforming processing is not applied to the block and the first quantization parameter is less than a reference value, encodes the block using the reference value as a quantization parameter, and, if it is determined that a pallet mode is applied to the block and the first quantization parameter is less than a reference value, encodes the block using the reference value as a quantization parameter for an escape value, wherein the reference value used if it is determined that the transforming processing is not applied to the block and the reference value used for the escape value are the same.

Abstract: The block to be encoded is encoded using a first quantization parameter corresponding to a coefficient of each color component in the block to be encoded when it is determined that orthogonal transform processing is to be performed on the coefficient of each color component in the block to be encoded, and the block to be encoded is encoded using a second quantization parameter obtained by correcting the first quantization parameter when it is determined that orthogonal transform processing is not to be performed on the coefficient of each color component in the block to be encoded. A predetermined determination based on the first quantization parameter and a predetermined value is performed, and the second quantization parameter is derived by correcting the first quantization parameter in accordance with a determination result of the predetermined determination.

Abstract: An image encoding apparatus for dividing an image into one or more sub-pictures and encoding the one or more sub-pictures, comprises a first encoding unit configured to encode a syntax element corresponding to the number of sub-pictures included in the image, and a second encoding unit configured to encode information used for specifying arrangement of sub-pictures in the image. Only when a numerical value indicated by the syntax element is one or more, the second encoding unit encodes the information used for specifying the arrangement of the sub-pictures in the image.

Abstract: An image is divided into a plurality of tiles and the tile is divided into rectangular regions each including at least one block row formed from a plurality of blocks each having a size smaller than the tile. If each slice in the image includes only one rectangular region, based on the number of blocks in a vertical direction in the rectangular region, the number of pieces of information for specifying a start position of coded data of the block row in the slice is specified. A bitstream in which at least the pieces of information, whose number is as many as the specified number, information representing that each slice in the image is formed by only one rectangular region, and the coded data of the block row are multiplexed is generated.

Abstract: An image is divided into a plurality of tiles and the tile is divided into rectangular regions each including at least one block row formed from a plurality of blocks each having a size smaller than the tile. Based on information representing the number of rectangular regions included in a slice of the image, the rectangular region included in the slice is specified. Based on the number of blocks in a vertical direction in the specified rectangular region, the number of pieces of information for specifying a start position of coded data of the block row in the slice is specified. A bitstream in which at least the pieces of information whose number is specified, the information representing the number of rectangular regions included in the slice, and the coded data of the block row are multiplexed is generated.

Abstract: An image is divided into rectangular regions each including at least one block row, and the image is divided into rectangular slices or slices to be processed in raster order. In a case where the image is divided into the rectangular slices, based on first information for specifying a rectangular region to be processed first and second information for specifying a rectangular region to be processed last, the rectangular regions in the rectangular slice is specified. Based on the number of blocks in a vertical direction in each of the specified rectangular regions, the number of pieces of information for specifying a start position of coded data of the block row in the rectangular slice is specified. A bitstream in which at least the pieces of information, the first and second information, and the coded data are multiplexed is generated.

Abstract: This invention suppresses degradation of subjective image quality while improving the coding efficiency of residual coefficients of two chroma components. To this, an image coding device that codes image data constituted by one luma component and two chroma components according to the invention, comprises quantizing unit that performs an orthogonal transform on each of components of a block obtained by dividing an image to be coded, and quantizes transform coefficients of each of the components obtained from the orthogonal transform; and coding unit that codes residual coefficients obtained by the quantizing unit, wherein when coding the transform coefficients of the orthogonal transform of the two chroma components in an integrated manner, the coding unit quantizes transform coefficients of the orthogonal transform obtained from the integration using a predetermined quantization matrix, and codes residual coefficients obtained from the quantizing.

Abstract: Decoding corresponding to a first array of quantized coefficients including an N×M array corresponding to a first block and data corresponding to a second array including an N×M array corresponding to a second block. Deriving a first array of orthogonal transform coefficients from the first array of quantized coefficients by using at least a first quantization matrix of an N×M array of elements, and derives a second array of orthogonal transform coefficients from the second array by using at least a second quantization matrix of an N×M array of elements. Performing inverse orthogonal transform on the first array of orthogonal transform coefficients to generate a P×Q array of pixels of first prediction residuals, and performs inverse orthogonal transform on the second array of orthogonal transform coefficients to generate an N×M array of pixels of second prediction residuals.

Abstract: An image decoding apparatus decodes a bit stream generated by coding an image and decodes coded data included in the bit stream and corresponding to a target block to be decoded in the image. The apparatus includes a first determining unit configured to determine whether the target block is prediction-coded or palette-coded; a second determining unit configured to determine whether or not a pixel in the target block is escape-coded if the first determining unit determines that the target block is palette-coded; and a first decoding unit configured to decode the target block by using a second quantization parameter different from a first quantization parameter if the second determining unit determines that the pixel is escape-coded. The first quantization parameter is used to decode the coded data in a case where the first determining unit determines that the target block is prediction-coded.

Abstract: A decoding unit decodes data corresponding to an N×M array of quantized coefficients from a bit stream, An inverse quantization unit derives orthogonal transform coefficients from the N×M array of quantized coefficients by using at least a quantization matrix. An inverse orthogonal transform unit performs inverse orthogonal transform on the orthogonal transform coefficients generated by the inverse quantization unit to generate prediction residuals corresponding to a block of a P×Q array of pixels. An inverse quantization unit derives the orthogonal transfonn coefficients by using at least a quantization matrix of an N×M array of elements, and the inverse orthogonal transform unit generates prediction residuals for the P×Q array of pixels having a size larger than the N×M array.

Abstract: An orthogonal transform unit orthogonally transforms prediction residuals in a block of a P×Q array of pixels, thereby generating an N×M (N is an integer satisfying N<P, and M is an integer satisfying M<Q) array of orthogonal transform coefficients. A quantization unit quantizes the N×M array of the orthogonal transform coefficients using at least a quantization matrix of an N×M array of elements, and thereby generates an N×M array of quantized coefficients.

Abstract: An image encoding apparatus for encoding an image comprises a generation unit configured to generate, from a first quantization matrix having a size of N×N (N is a positive integer), a second quantization matrix having a size of P×Q (P and Q are positive integers which satisfy P<N<Q, and the size of P×Q indicates a size of P in a horizontal direction and a size of Q in a vertical direction), and a quantization unit configured to quantize transformation coefficients in a sub-block having a size corresponding to the size of P×Q using the second quantization matrix.

Abstract: The present invention is made to enable switching between lossless coding which prioritizes compatibility with a lossy coding process and lossless coding which prioritizes compression performance. An image coding apparatus of the present invention includes the following configuration. The image coding apparatus which encodes an image on a block-by-block basis includes a first coding unit and a second coding unit. The first coding unit performs irreversible compression coding on a received first block. The second coding unit performs reversible compression coding on a received second block. The second coding unit encodes the second block by using either of a first intra prediction mode for performing intra prediction on a block-by-block basis and a second intra prediction mode for performing intra prediction on a pixel-by-pixel basis.

Abstract: An index, indicating a vector representing a spatial relationship between a block to be encoded and at least one block spatially at the periphery of the block to be encoded, is encoded in a case where an coding mode to encode the block to be encoded is a first coding mode, and an index, indicating a vector representing a spatial relationship between the block to be encoded and at least one block spatially at the periphery of the block to be encoded, and a vector correlated with a block within an image that is different from the image to be encoded, is encoded in a case where the coding mode to encode the block to be encoded is a second coding mode.

Abstract: The present invention provides an image encoding apparatus for encoding a sequence of images, where the apparatus comprises a prediction unit which generates, for a target block to be encoded having a predetermined size in an image, a predicted image from both an intra-prediction image and an inter-prediction image, and obtains prediction errors that are differences between the target block and the predicted image; a transform unit which frequency-transforms the prediction errors, a quantization unit which quantize, using a quantization matrix, the transform coefficients, and an encoding unit which entropy-encodes quantized transform coefficients, wherein the quantization unit obtains the quantization matrix, using at least one of a predetermined quantization matrix for the intra-prediction and a predetermined quantization matrix for inter-prediction.

Abstract: In prediction, one of a first mode for deriving, using pixels in an image including a target block, predicted pixels in the target block, a second mode for deriving the predicted pixels in the target block using pixels in an image different from the image including the target block, a third mode for generating the predicted pixels in the target block using both the pixels in the image including the target block and pixels in the different image can be used. If the third mode is used in at least one of the first and second blocks, the intensity of deblocking filter to be performed for the boundary between the first and second blocks is set to the same intensity as in a case in which the first mode is used in at least one of the first and second blocks.