Abstract: A three-dimensional data encoding method includes: encoding geometry information of a plurality of three-dimensional points represented by a tree structure; and generating a bitstream including the geometry information encoded and division number information indicating a total number of divisions of each of a plurality of nodes included in the tree structure. The division number information includes common division number information collectively indicating the total number of divisions of two or more nodes among the plurality of nodes.

Abstract: A three-dimensional data encoding method includes: obtaining three-dimensional points; generating a data unit including one or more prediction trees, using the three-dimensional points; and generating a bitstream including the data unit and control information. The control information includes tree information about the one or more prediction trees, and the tree information includes number information indicating a total number of prediction trees included in the data unit.

Abstract: A three-dimensional data encoding method includes: obtaining data units each including three-dimensional points; encoding the three-dimensional points included in each of the data units; and generating a bitstream including encoded data obtained by encoding the three-dimensional points. In the encoding: geometry information of three-dimensional points included in a data unit to be encoded is converted into occupancy maps using an N-ary tree; each of the occupancy maps is converted into an index using a table indicating a correspondence relation between occupancy maps and indexes, and the encoded data is generated by encoding the index; the table is updated according to the index resulting from the conversion, and is stored into the memory; and when it is determined that the table stored in the memory is not to be initialized, encoding of a next data unit is started using the table stored in the memory.

Abstract: A three-dimensional data encoding method includes: obtaining a data unit including three-dimensional points; encoding the three-dimensional points included in the data unit; and generating a bitstream including encoded data obtained by encoding the data unit. In the encoding: a first determination for determining whether to continuously use a context to encode the data unit is made, the context being used in encoding a previous data unit preceding the data unit; and the data unit is encoded using a context according to a result of the first determination. In the first determination, when the data unit is a lead data unit in a random access unit, it is determined not to continuously use the context used in encoding the previous data unit.

Abstract: A three-dimensional data encoding method including: encoding tile information including information on N (N is an integer greater than or equal to 0) subspaces of a target space including three-dimensional points, and encoding point cloud data of the three-dimensional points based on the tile information; and generating a bitstream including the point cloud data encoded. The tile information includes N subspace coordinate information indicating coordinates of the N subspaces. The N subspace coordinate information each include three coordinate information each indicating a coordinate in one of three axial directions in a three-dimensional orthogonal coordinate system. When N is 1 or greater: in the encoding of the tile information, each of the three coordinate information is encoded using a first fixed length; and in the generating of the bitstream, the bitstream which includes the N subspace coordinate information encoded and first fixed length information indicating the first fixed length is generated.

Abstract: A three-dimensional data encoding method includes: encoding information of a target node included in an N-ary tree structure of three-dimensional points included in three-dimensional data; and generating a bitstream including the information of the target node encoded. In the encoding, the target node is encoded based on reference limitation information indicating a referable neighbor node among neighbor nodes spatially neighboring the target node. In the generating, when the target node is encoded by reference to information of a first neighbor node, the bitstream further including encoding processing information is generated, the encoding processing information indicating a processing method in the encoding; and when the target node is encoded without reference to the information of the first neighbor node, the bitstream is generated without including the encoding processing information in the bitstream.

Abstract: A three-dimensional data encoding method includes: calculating a prediction residual that is a difference between information of a three-dimensional point included in point cloud data and a predicted value; quantizing the prediction residual using a quantization parameter; determining, using the quantization parameter, a second bit count of second information indicating a first bit count of first information on the prediction residual quantized; and generating a bitstream including the first information, the second information, and third information indicating the second bit count.

Abstract: A three-dimensional data encoding method includes: generating frame data items by encoding point cloud data items of frames; and generating a bitstream including the frame data items. Each of the frame data items includes processing unit data items corresponding to processing units obtained by dividing one frame. Each of the processing unit data items includes a frame identifier indicating a frame to which the processing unit data item belongs and a processing unit identifier indicating a processing unit corresponding to the processing unit data item. Values of the frame identifiers corresponding to the frame data items placed in the bitstream are set in a predetermined order, and values of the processing unit identifiers corresponding to the processing unit data items placed in the frame data item are set in an arbitrary order.

Abstract: A transmission device that performs multiple-input multiple-output (MIMO) transmission of transmit data using a plurality of fundamental bands. The transmission device includes an error correction coding unit, a mapping unit, and a MIMO coding unit. The error correction coding unit, for each data block of predefined length, performs error correction coding and thereby generates an error correction coded frame. The mapping unit maps each predefined number of bits in the error correction coded frame to a corresponding symbol and thereby generates an error correction coded block. The MIMO coding unit performs MIMO coding with respect to the error correction coded block. Components of data included in the error correction coded block are allocated to at least two of the fundamental bands and transmitted.

Abstract: A three-dimensional data encoding method includes: encoding attribute information of three-dimensional points, the three-dimensional points being classified into one or more layers, based on geometry information of the three-dimensional points; and generating a bitstream including the attribute information encoded. In encoding of attribute information of a current three-dimensional point included in the three-dimensional points, same layer reference is performed when a total number of the one or more layers is one, the same layer reference including generating a prediction value of the attribute information of the current three-dimensional point by reference to attribute information of an other three-dimensional point included in a same layer as the current three-dimensional point.

Abstract: A three-dimensional data encoding method includes: quantizing geometry information of each of three-dimensional points, using a first quantization parameter; quantizing a first luminance using a second quantization parameter and quantizing a first chrominance using a third quantization parameter, the first luminance and the first chrominance indicating a first color among attribute information of each of the three dimensional points; and generating a bitstream including the geometry information quantized, the first luminance quantized, the first chrominance quantized, the first quantization parameter, the second quantization parameter, and a first difference between the second quantization parameter and the third quantization parameter.

Abstract: A three-dimensional data encoding method includes: encoding divided data items to generate encoded data items each corresponding to a respective one of the divided data items, the divided data items being included in subspaces obtained by dividing a current space including three-dimensional points, the divided data items each including one or more three-dimensional points among the three-dimensional points; and generating a bitstream including the encoded data items and control information items each corresponding to a respective one of the encoded data items. Each of the control information items includes a first identifier and a second identifier. The first identifier indicates a subspace corresponding to an encoded data item corresponding to the control information item, and the second identifier indicates a divided data item corresponding to the encoded data item corresponding to the control information item.

Abstract: A three-dimensional data encoding method includes: encoding a first flag indicating whether a node having a parent node different from a parent node of a current node is to be referred to in encoding of the current node included in an n-ary tree structure of three-dimensional points included in three-dimensional data; selecting a coding table from N coding tables according to occupancy states of neighboring nodes of the current node, and performing arithmetic encoding on information of the current node using the coding table selected, when the first flag indicates that the node is to be referred to; and selecting a coding table from M coding tables according to the occupancy states of the neighboring nodes of the current node, and performing arithmetic encoding on information of the current node using the coding table selected, when the first flag indicates that the node is not to be referred to.

Abstract: A three-dimensional data encoding method includes: shifting point cloud data indicating three-dimensional positions in a three-dimensional space by a first shift amount; dividing the point cloud data into pieces of sub point cloud data; shifting each of the pieces of sub point cloud data by a second shift amount based on a position of one of the subspaces that includes the sub point cloud data, the pieces of sub point cloud data being included in the point cloud data shifted by the first shift amount; and encoding the pieces of sub point cloud data shifted, to generate a bitstream. The bitstream includes first shift information for calculating the first shift amount, and pieces of second shift information each for calculating a corresponding one of second shift amounts by which the pieces of sub point cloud data are shifted and each of which is the second shift amount.

Abstract: A three-dimensional data encoding method includes: generating a first information item and a second information item, the first information item indicating one or more directions toward a three-dimensional point cloud, the second information item being information for each of the one or more directions and indicating whether the three-dimensional point cloud is visible from the direction; and encoding point cloud data of the three-dimensional point cloud.

Abstract: A three-dimensional data encoding method includes: obtaining a data unit including three-dimensional points; generating one or more prediction trees using the three-dimensional points included in the data unit; performing predictive encoding on position information items of one or more three-dimensional points among the three-dimensional points, using a prediction tree including the one or more three-dimensional points; and generating a bitstream including encoded data resulting from the predictive encoding. In the performing, (i) a prediction value in a specific prediction mode is obtained, and (ii) one or more prediction residuals are calculated for each of the one or more three-dimensional points, the one or more prediction residuals each being a difference between a position information item of the three-dimensional point and the prediction value.

Abstract: A three-dimensional data encoding method includes: obtaining first three-dimensional points; encoding the first three-dimensional points using one of a plurality of encoding schemes; and generating a bitstream including first encoded data and a first identification information item, the first encoded data being obtained by encoding the first three-dimensional points. The encoding of the first three-dimensional points includes: determining whether a context used for encoding is continuously used; and encoding the first three-dimensional points using a context corresponding to a determination result in the determining, the context being included in contexts used in an encoding scheme used for the encoding and included in the encoding schemes, and the first identification information item includes the determination result in the determining.

Abstract: A three-dimensional data encoding method includes: obtaining a plurality of three-dimensional points; generating a prediction tree using the plurality of three-dimensional points; predictive-encoding geometry information of the plurality of three-dimensional points using the prediction tree; and generating a bitstream including encoded data obtained from the predictive-encoding, a total number of three-dimensional points included in the prediction tree, and identification information indicating whether or not to rearrange the plurality of three-dimensional points in Morton order.

Abstract: A three-dimensional data encoding method includes: generating one or more items of first information each of which is common to two or more frames among a plurality of frames and includes information indicating one or more partial regions included in a frame; generating items of second information each of which is for a different one of the plurality of frames and includes information indicating a feature of a partial point cloud consisting of three-dimensional points of each of the partial regions; and encoding, for each item of data of the partial point cloud, point cloud data of the three-dimensional points. The items of second information include information indicating one of the one or more items of first information.

Abstract: A three-dimensional data encoding method includes: encoding divided data items to generate encoded data items each corresponding to a respective one of the divided data items, the divided data items being included in subspaces obtained by dividing a current space including three-dimensional points, the divided data items each including one or more three-dimensional points among the three-dimensional points; and generating a bitstream including the encoded data items and control information items each corresponding to a respective one of the encoded data items. Each of the control information items includes a first identifier and a second identifier. The first identifier indicates a subspace corresponding to an encoded data item corresponding to the control information item, and the second identifier indicates a divided data item corresponding to the encoded data item corresponding to the control information item.