Abstract: An image coding method includes: deriving a candidate for a motion vector of a current block from a co-located motion vector; adding the candidate to a list; selecting the motion vector of the current block from the list; and coding the current block, wherein the deriving includes: deriving the candidate by a first derivation scheme in the case of determining that each of a current reference picture and a co-located reference picture is a long-term reference picture; and deriving the candidate by a second derivation scheme in the case of determining that each of the current reference picture and the co-located reference picture is a short-term reference picture.

Abstract: A three-dimensional data encoding method includes: classifying three-dimensional points included in point cloud data into layers, based on geometry information of the three-dimensional points; generating first information indicating whether to permit referring to, for a current three-dimensional point included in the three-dimensional points, attribute information of another three-dimensional point belonging to a same layer as the current three-dimensional point; and encoding attribute information of the current three-dimensional point to generate a bitstream, by or without referring to the attribute information of the other three-dimensional point according to the first information. The bitstream includes the first information.

Abstract: A moving picture coding method includes: coding a coding target block using a motion vector; generating motion vector predictors; and coding the motion vector using one of the motion vector predictors generated in the generating of the motion vector predictors. In the generating of the motion vector predictors, a replacement vector which replaces a temporal motion vector predictor is added to the motion vector predictors when it is impossible to obtain the temporal motion vector predictor from a block which is included in a coded picture different from the coding target picture and corresponds to the coding target block.

Abstract: An image coding method includes: generating a first flag indicating whether or not a motion vector predictor is to be selected from among one or more motion vector predictor candidates; generating a second flag indicating whether or not a motion vector predictor is to be selected from among the one or more motion vector predictor candidates in coding a current block to be coded in a predetermined coding mode, when the first flag indicates that a motion vector predictor is to be selected; and generating a coded signal in which the first flag and the second flag are included in header information, when the first flag indicates that a motion vector predictor is to be selected.

Abstract: A method of encoding video including: writing a plurality of predetermined buffer descriptions into a sequence parameter set of a coded video bitstream; writing a plurality of updating parameters into a slice header of the coded video bitstream for selecting and modifying one buffer description out of the plurality of buffer descriptions; and encoding a slice into the coded video bitstream using the slice header and the modified buffer description.

Abstract: A transmitting method for transmitting a bitstream to a terminal is provided. The bit stream is generated by coding a current block of a picture and has an index for identifying a motion vector candidate from a motion vector candidate list. The motion vector candidate list is generated and includes motion vector candidates and a value for each motion vector candidate. A second candidate is arranged before a first candidate in the motion vector candidate list. The first candidate is sorted before the second candidate in the motion vector candidate list based on the values of the first and second candidates. The value of the first candidate is higher than the value of the second candidate. For each motion vector candidate, the value is based on a number of times the motion vector candidate is selected as a motion vector predictor for neighboring blocks.

Abstract: A three-dimensional data storage method includes: acquiring one or more units in which an encoded stream generated by encoding point cloud data is stored; and storing the one or more units into a file. The storing includes storing, in control information for the file, information indicating that data stored in the file is data generated by encoding the point cloud data.

Abstract: A three-dimensional data encoding method includes: calculating a predicted value of a position of a three-dimensional point according to one of inter prediction and intra prediction; calculating a residual between the predicted value and the position; arithmetic-encoding the residual using a first context when the predicted value is calculated according to the inter prediction; and arithmetic-encoding the residual using a second context different from the first context when the predicted value is calculated according to the intra prediction. The residual is expressed by third residual information indicating a bit count of the residual.

Abstract: A three-dimensional data encoding method uses a first encoding scheme and a second encoding scheme different from the first encoding scheme, and includes: (i) transforming a first quantization parameter to a first scale value or (ii) transforming the first scale value to the first quantization parameter, based on a first table indicating a correspondence between values of the first quantization parameter and values of the first scale value and being shared between the first encoding scheme and the second encoding scheme; performing encoding including a first quantization process to generate encoded attribute information, the first quantization process being a process of dividing, by the first scale value, each of first coefficient values based on items of attribute information of three-dimensional points included in point cloud data; and generating a bitstream including the encoded attribute information and the first quantization parameter.

Abstract: A video encoding method using a plurality of reference pictures includes: selecting whether or not a resilient picture referencing scheme is to be used for encoding video; writing a parameter indicating the selection into a header of an encoded video bitstream; and encoding a picture using inter-picture prediction using a result of the selection.

Abstract: A three-dimensional data encoding method includes encoding information of a current node included in an N-ary tree structure of three-dimensional points included in three-dimensional data, where N is an integer greater than or equal to 2. In the encoding, reference to information of a first node included in neighboring nodes spatially neighboring the current node is permitted, and reference to information of a second node included in the neighboring nodes is prohibited, the first node having a same parent node as the current node, the second node having a different parent node from the parent node of the current node.

Abstract: An image coding method includes: selecting a first picture from plural pictures; setting a first temporal motion vector prediction flag which is associated with the first picture and is a temporal motion vector prediction flag indicating whether or not temporal motion vector prediction is to be used, to indicate that the temporal motion vector prediction is not to be used, and coding the first temporal motion vector prediction flag; coding the first picture without using the temporal motion vector prediction; and coding a second picture which follows the first picture in coding order, with referring to a motion vector of a picture preceding the first picture in coding order being prohibited.

Abstract: A three-dimensional data encoding method includes: performing motion compensation on a plurality of encoded point clouds; merging the plurality of encoded point clouds that have been motion compensated to generate a reference point cloud; generating an N-ary tree structure of a current point cloud, where N is an integer greater than or equal to 2; and encoding the N-ary tree structure of the current point cloud using the reference point cloud.

Abstract: A three-dimensional data encoding method includes: determining a first three-dimensional point that is encoded and has a position represented by a first polar coordinate system having a first position as a reference; and determining (i) a distance between the first position and a second position, (ii) a first angle formed by a first line connecting the first position and the second position and a second line connecting the first position and the first three-dimensional point, and (iii) a first distance from the first position to the first three-dimensional point in the first polar coordinate system, to calculate a prediction value of a second distance from the second position to a second three-dimensional point that is not yet encoded and has a position represented by a second polar coordinate system having the second position as a reference.

Abstract: A three-dimensional data encoding method includes: determining whether a first valid node count is greater than or equal to a first threshold value predetermined, the first valid node count being a total number of valid nodes that are nodes each including a three-dimensional point, the valid nodes being included in first nodes belonging to a layer higher than a layer of a current node in an N-ary tree structure of three-dimensional points included in point cloud data, N being an integer greater than or equal to 2; and, when the first valid node count is greater than or equal to the first threshold value, performing first encoding on attribute information of the current node, the first encoding including a prediction process in which second nodes are used, the second nodes including a parent node of the current node and belonging to a same layer as the parent node.

Abstract: A three-dimensional data encoding method includes: obtaining second attribute information obtained by transforming first attribute information of a three-dimensional point in at least one frame among frames, the frames constituting a sequence; and encoding the second attribute information to generate a bitstream. The transforming is different from quantization, and the bitstream further includes: at least one first parameter provided for the sequence for the transforming; and at least one second parameter provided for each of the at least one frame for the transforming.

Abstract: The image coding method includes: determining a context in a current block in the image, from among a plurality of contexts; and performing arithmetic coding on the control parameter for the current block to generate a bitstream corresponding to the current block, wherein in the determining: the context is determined under a condition that control parameters of neighboring blocks of the current block are used, when the signal type is a first type, the neighboring blocks being a left block and an upper block of the current block; and the context is determined under a condition that the control parameter of the upper block is not used, when the signal type is a second type, and the second type is (i) “merge_flag”, (ii) “ref_idx_l0” or “ref_idx_l1”, (iii) “inter_pred_flag”, (iv) “mvd_l0” or “mvd_l1”, (v) “no_residual_data_flag”, (vi) “intra_chroma_pred_mode”, (vii) “cbf_luma”, and (viii) “cbf_cb” or “cbf_cr”.

Abstract: A three-dimensional data encoding method includes: generating predicted position information using position information on three-dimensional points included in three-dimensional reference data associated with a time different from a time associated with current three-dimensional data; and encoding position information on three-dimensional points included in the current three-dimensional data, using the predicted position information.

Abstract: A three-dimensional data encoding method of encoding three-dimensional points obtained by a sensor includes: encoding local coordinate information indicating sets of local coordinates that are coordinates of the three-dimensional points and are dependent on a location of the sensor; and generating an encoded bitstream including the local coordinate information encoded and global coordinate information indicating global coordinates that are coordinates of a reference point or at least one of the three-dimensional points and are independent from the location of the sensor.

Abstract: An apparatus is provided for decoding last position information indicating a horizontal position and a vertical position of a last non-zero coefficient in a predetermined order within a current block to be decoded, the current block being included in a picture and including a plurality of coefficients. The apparatus includes one or more processors, a communication unit, and storage coupled to the one or more processors and the communication unit. The communication unit is configured to transmit a request for a bitstream to an external system, and receive the bitstream from the external system. The one or more processors are configured to obtain the bitstream, perform first arithmetic decoding, perform second arithmetic decoding, derive a horizontal component of the last position information, and derive a vertical component of the last position. A system for decoding and a displaying method are also provided.