Abstract: An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry determines one or more tiles included in a picture and one or more subpictures included in the picture, according to a constraint condition that each tile of the one or more tiles includes at least one subpicture of the one or more subpictures entirely and the each tile does not include another subpicture of the one or more subpictures partially.

Abstract: An encoder includes circuitry and memory connected to the circuitry. In operation, the circuitry: stores MV information and correction processing information into a FIFO buffer for an HMVP mode in association, the MV information being derived for a processed block and correction processing information being related to correction processing of a prediction image of the processed block; registers, in a prediction candidate list for a merge mode, one or more prediction candidates each being a combination of MV information and correction processing information, the prediction candidates including a prediction candidate which is a combination of the motion vector information and the correction processing information stored in the FIFO buffer; and selects a prediction candidate from the prediction candidate list when a current block is to be processed in the merge mode, and performs correction processing of a prediction image of the current block, based on the correction processing information.

Abstract: An encoder includes circuitry and memory coupled to the circuitry. In operation, the circuitry: encodes a video using (i) a decoding parameter set (DPS) which is identified based on presence of the DPS in a bitstream and (ii) a sequence parameter set (SPS) which is identified based on an identifier for the SPS.

Abstract: An encoder that encodes a video includes a processor and memory. Using the memory, the processor: derives a prediction error of an image included in the video, by subtracting a prediction image of the image from the image; determines a secondary transform basis based on a primary transform basis, the primary transform basis being a transform basis for a primary transform to be performed on the prediction error, the secondary transform basis being a transform basis for a secondary transform to be performed on a result of the primary transform; performs the primary transform on the prediction error using the primary transform basis; performs the secondary transform on a result of the primary transform using the secondary transform basis; performs quantization on a result of the secondary transform; and encodes a result of the quantization as data of the image.

Abstract: An encoder encodes a video, and includes: circuitry; and memory coupled to the circuitry. Using the memory, the circuitry: obtains at least two items of prediction information for a first partition included in the video; derives at least one template from neighboring samples which neighbor the first partition; calculates at least two costs, using the at least one template and the at least two items of prediction information; using the at least two costs, (i) determines at least one splitting direction for the first partition or (ii) assigns one of the at least two items of prediction information to a second partition split from the first partition according to the splitting direction, and another thereof to a third partition split from the first partition according to the splitting direction; and encodes the first partition according to the splitting direction and the at least two items of prediction information.

Abstract: An encoder that encodes a video includes circuitry and memory connected to the circuitry. In operation, the circuitry: generates a prediction image on a per sub-block basis; and when a sub-block size is 4×4, applies a boundary smoothing process only to sub-block boundaries having boundary positions that are integer multiples of 8.

Abstract: An encoder includes circuitry and memory coupled to the circuitry. In operation, for a group of layers including at least one output layer, the circuitry generates a bitstream including a common header for one or more layers in the group of layers, in which when a total number of layers in the group of layers is 1, (i) performance requirement information indicating a performance requirement for a decoder is signaled in the common header, and (ii) a hypothetical reference decoder (HRD) parameter is not signaled in the common header. The bitstream includes the common header and encoded data of at least one image in the at least one output layer. The common header does not include the HRD parameter.

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: 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: A three-dimensional data creation method in a client device includes: creating three-dimensional data of a surrounding area of the client device using sensor information that is obtained through a sensor equipped in the client device and indicates a surrounding condition of the client device; estimating a self-location of the client device using the three-dimensional data created; and transmitting the sensor information obtained to a server or an other client device.

Abstract: According to one aspect of the present disclosure, a decoder includes memory and a processor coupled to the memory. The processor is configured to split a current picture into tiles, generate a slice having a rectangular shape and located at a lower-right corner of the current picture, the slice including at least a part of a tile among the tiles, generate first information on a region of the slice with header information, the header information not including information identical to the first information, and decode the slice with the first information.

Abstract: A decoding method includes: determining two partitions in a current block according to a geometric partitioning mode; deriving an angular intra prediction mode from the geometric partitioning mode using a mapping relation between geometric partitioning modes and angular intra prediction modes; and predicting a first partition among the two partitions according to the angular intra prediction mode, in which in the deriving of the angular intra prediction mode, when a shape of the current block is square, a first mapping relation is used to derive the angular intra prediction mode, and when the shape of the current block is not square, a second mapping relation different from the first mapping relation is used to derive the angular intra prediction mode.

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: An encoder which codes a moving picture includes: a processor; and a memory, wherein the processor, using the memory: subtracts a prediction image of an image included in the moving picture from the image so as to derive a prediction error; sequentially selects a plurality of transform basis candidates; derives an evaluation value of a transform basis candidate selected; compares the evaluation value with a threshold value; based on a result of the comparison, skips selection of one or more transform basis candidates that have not been selected; determines the transform basis from one or more transform basis candidates selected; performs the transform of the prediction error, using the transform basis; quantizes a result of the transform; and codes a result of the quantization as data of the image.

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: An encoder includes circuitry and memory coupled to the circuitry. The circuitry determines whether to split a current luma virtual pipeline decoding unit (VPDU) into smaller blocks. When it is determined not to split the current luma VPDU into smaller blocks, the circuitry predicts a block of chroma samples without using luma samples. When it is determined to split the luma VPDU into smaller blocks, the circuitry predicts the block of chroma samples using luma samples. The circuitry encodes the block using the predicted chroma samples.

Abstract: A transmission method in the present disclosure includes; obtaining an image and image signal characteristics information indicating one of an opto-electrical transfer function (OETF) or an electro-optical transfer function (EOTF) as image signal characteristics of the image; and transmitting a signal including the image and the image signal characteristics information. According to the transmission method in the present disclosure, a receiving device that received a high dynamic range (HDR) image and a standard dynamic range (SDR) image transmitted through broadcasting or the like can display these images appropriately.

Abstract: An image encoder writes a first parameter and a second parameter to a bitstream, and derives a partition mode based on the first and second parameters. Responsive to the derived partition mode being a first partition mode, the image encoder executes the first partition mode including: splitting a block of a picture into a plurality of first blocks including a N×2N block sized N pixels by 2N pixels; splitting the N×2N block, wherein a ternary split is allowed to split the N×2N block in a vertical direction, which is a direction along the 2N pixels, into a plurality of sub blocks including at least one sub block sized N/4×2N, while a binary split is not allowed to split the N×2N block in the vertical direction into two sub blocks that are equally sized N/2×2N; and encoding the plurality of sub blocks.

Abstract: An encoder which includes circuitry and memory. Using the memory, the circuitry generates a list which includes candidates for a first motion vector for a first partition. The list has a maximum list size and an order of the candidates, and at least one of the maximum list size or the order of the candidates is dependent on at least one of a partition size or a partition shape of the first partition. The circuitry selects the first motion vector from the candidates included in the list; encodes an index indicating the first motion vector among the candidates in the list into the bitstream based on the maximum list size; and generates the predicted image for the first partition using the first motion vector.

Abstract: An encoder includes circuitry and memory. Using the memory, the circuitry performs prediction on an image. A motion vector predictor list used in the prediction includes a spatially neighboring motion vector predictor obtained from a block spatially neighboring a current block, and a spatially broad motion vector predictor obtained from a block positioned at any of a plurality of predetermined positions in a second range that is broader than a first range that spatially neighbors the current block. The plurality of predetermined positions are defined by a regular interval using the top-left of a current picture as a reference point.