Abstract: A three-dimensional data encoding method of encoding three-dimensional points includes: re-ordering, in a re-ordered data order, pieces of attribute information of the three-dimensional points arranged in a predetermined order; encoding the pieces of attribute information re-ordered in the re-ordering, in accordance with the re-ordered data order; and generating a bitstream including (i) order information indicating the predetermined order and (ii) the pieces of attribute information encoded in the encoding.

Abstract: A three-dimensional data encoding method includes: transforming pieces of attribute information of three-dimensional points included in point cloud data into coefficient values; and encoding the coefficient values to generate a bitstream. In the transforming, weighting calculation is performed hierarchically to generate the coefficient values belonging to one of layers, the weighting calculation separating each of the pieces of attribute information into a high-frequency component and a low-frequency component. In the weighting calculation, the weighting calculation is performed using weights fixed or not fixed in the layers. The bitstream includes first information indicating whether to fix the weights in the layers.

Abstract: A three-dimensional data encoding method includes: calculating coefficient values from pieces of attribute information of three-dimensional points included in point cloud data; quantizing the coefficient values to generate quantization values; and generating a bitstream including the quantization values. The three-dimensional points corresponding to the coefficient values belong to one layer among one or more layers. Each of a predetermined number of layers among the one or more layers is assigned a quantization parameter for the layer. In the quantizing, (i) when a quantization parameter is assigned to a layer to which each of the coefficient values belongs, the coefficient value is quantized using the quantization parameter, and (ii) when the quantization parameter is not assigned to a layer to which each of the coefficient values belongs, the coefficient value is quantized using a quantization parameter assigned to one layer among the predetermined number of the layers.

Abstract: A three-dimensional data encoding method includes: encoding three-dimensional points each located in any one of a plurality of regions, on a per region basis, to generate encoded three-dimensional points; generating connectivity information generated based on a relationship between a first region among the plurality of regions and second regions aside from the first region among the plurality of regions, the connectivity information including (i) tile information indicating values each uniquely assigned to a different one of the plurality of regions and (ii) relation information indicating that the first region and one of the second regions are related; and generating a bitstream including the connectivity information generated and the encoded three-dimensional points.

Abstract: A three-dimensional data decoding method includes: obtaining a bitstream including encoded three-dimensional points generated by encoding three-dimensional points each of which is represented by a first angle, a second angle, and a distance; determining a reference three-dimensional point among the three-dimensional points; and performing, according to the first angle of the reference three-dimensional point, at least one of arithmetic decoding or debinarizing on encoded information of a current encoded three-dimensional point included in the encoded three-dimensional points to generate information of a current three-dimensional point included in the three-dimensional points, the information excluding the first angle.

Abstract: A three-dimensional data encoding method includes: encoding first information of a first current node or second information of a second current node, the first current node being included in an N-ary tree structure of first three-dimensional points included in a first three-dimensional point cloud, N being 2 or 4, the second current node being included in an octree structure of second three-dimensional points included in a second three-dimensional point cloud The encoding of the first information or the second information includes encoding the first information using a first encoding pattern including a pattern common to a second encoding pattern used in encoding the second information.

Abstract: A three-dimensional data encoding method includes: transforming pieces of attribute information of three-dimensional points included in point cloud data into coefficient values; and encoding the coefficient values to generate a bitstream. In the transforming, weighting calculation is performed hierarchically to generate the coefficient values belonging to one of layers, the weighting calculation separating each of the pieces of attribute information into a high-frequency component and a low-frequency component. In the weighting calculation, the weighting calculation is performed using weights fixed or not fixed in the layers. The bitstream includes first information indicating whether to fix the weights in the layers.

Abstract: A three-dimensional data encoding method includes generating a bitstream by encoding subspaces included in a current space including three-dimensional points. In the generating of the bitstream: first information is stored in a first header which is common to the subspaces and included in the bitstream, the first information indicating first coordinates which are coordinates of the current space; and second information is stored in a second header which is provided on a subspace basis and included in the bitstream, the second information indicating a difference between second coordinates which are coordinates of a corresponding subspace among the subspaces and the first coordinates.

Abstract: An encoding device including memory and a circuit. In operation, the circuit: encodes first vertex information, second vertex information, and third vertex information, the first vertex information indicating a position of a first vertex of a first triangle that is a triangle in a three-dimensional mesh and on a first plane, the second vertex information indicating a position of a second vertex of the first triangle, the third vertex information indicating a position of a third vertex of the first triangle; and encodes, as fourth vertex information indicating a position of a fourth vertex of a second triangle, (i) dihedral angle information indicating a dihedral angle formed by the first plane and a second plane and (ii) identifying information for identifying a position of a fifth vertex that is a virtual vertex of a third triangle.

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: encoding first information of a first current node or second information of a second current node, the first current node being included in an N-ary tree structure of first three-dimensional points included in a first three-dimensional point cloud, N being 2 or 4, the second current node being included in an octree structure of second three-dimensional points included in a second three-dimensional point cloud The encoding of the first information or the second information includes encoding the first information using a first encoding pattern including a pattern common to a second encoding pattern used in encoding the second information.

Abstract: A traction control method and a traction control apparatus for a vehicle are provided. The traction control method includes: estimating driving torque for each wheel and a difference between left and right wheel rotation speeds; determining a situation, in which the difference between the left and right wheel rotation speeds exceeds a first set value, to be a split wheel spin situation; estimating a maximum coefficient of friction between a spinning wheel and a road surface in the split wheel spin situation and estimating a maximum driving torque, at which the road surface is acceptable, by the maximum coefficient of friction; and obtaining a difference between driving torque of the spinning wheel and the maximum driving torque to calculate a road surface limitation excess driving torque and determining entry into traction control when the road surface limitation excess driving torque exceeds a second set value.

Abstract: A three-dimensional data encoding method includes generating a bitstream by encoding subspaces included in a current space including three-dimensional points. In the generating of the bitstream: first information is stored in a first header which is common to the subspaces and included in the bitstream, the first information indicating first coordinates which are coordinates of the current space; and second information is stored in a second header which is provided on a subspace basis and included in the bitstream, the second information indicating a difference between second coordinates which are coordinates of a corresponding subspace among the subspaces and the first coordinates.

Abstract: A three-dimensional data encoding method includes: calculating coefficient values from pieces of attribute information of three-dimensional points included in point cloud data; quantizing the coefficient values individually to generate quantized values; and generating a bitstream including the quantized values. Each of the coefficient values belongs to any one of layers. In the quantizing, each of the coefficient values is quantized using a quantization parameter for a layer to which the coefficient value belongs among the layers, and the bitstream includes first information and pieces of second information, the first information indicating a reference quantization parameter, the pieces of second information being for calculating quantization parameters for the layers from the reference quantization parameter.

Abstract: A three-dimensional data encoding method includes: obtaining geometry information which includes first three-dimensional positions on a measurement target, and is generated by a measurer that radially emits an electromagnetic wave in different directions and obtains a reflected wave which is the electromagnetic wave that is reflected by the measurement target; generating a two-dimensional image including first pixels corresponding to the directions, based on the geometry information; and encoding the two-dimensional image to generate a bitstream. Each of the first pixels has a pixel value indicating a first three-dimensional position or attribute information of a three-dimensional point which is included in a three-dimensional point cloud and corresponds to a direction to which the first pixel corresponds among the directions.

Abstract: An encoding method for encoding three-dimensional points each having a position represented by a distance and an angle, the encoding method comprising: identifying three-dimensional points that belong to a second processing unit and have been encoded, for inter prediction of a first three-dimensional point belonging to a first processing unit; and selecting a reference three-dimensional point from the three-dimensional points identified to calculate an inter predicted value of the first three-dimensional point. The three-dimensional points identified include a second three-dimensional point and a third three-dimensional point, the second three-dimensional point having a second angle corresponding to a first angle of the first three-dimensional point, the third three-dimensional point having a third angle greater than the second angle.

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 three-dimensional data encoding method includes: combining first point cloud data and second point cloud data to generate third point cloud data; and encoding the third point cloud data to generate encoded data. The encoded data includes identification information indicating whether each of three-dimensional points included in the third point cloud data belongs to the first point cloud data or the second point cloud data.

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, first information is encoded, the first information indicating a range for one or more referable neighboring nodes among neighboring nodes spatially neighboring the current node, and the current node is encoded with reference to a neighboring node within the range.

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.