Abstract: A three-dimensional data encoding method includes: generating a bitstream by encoding subspaces included in a current space in which three-dimensional points are included. The bitstream includes encoded data respectively corresponding to the subspaces. In the generating of the bitstream, a list of information about the subspaces is stored in first control information included in the bitstream. The subspaces are respectively associated with identifiers assigned to the subspaces, and the first control information is common to the encoded data. Each of the identifiers assigned to the subspaces respectively corresponding to the encoded data is stored in a header of a corresponding one of the encoded data.

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 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: generating a bitstream by encoding subspaces included in a current space in which three-dimensional points are included. The bitstream includes encoded data respectively corresponding to the subspaces. In the generating of the bitstream, a list of information about the subspaces is stored in first control information included in the bitstream. The subspaces are respectively associated with identifiers assigned to the subspaces, and the first control information is common to the encoded data. Each of the identifiers assigned to the subspaces respectively corresponding to the encoded data is stored in a header of a corresponding one of the encoded data.

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: 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: A three-dimensional data encoding method includes: generating combined point cloud data by combining pieces of point cloud data; and generating a bitstream by encoding the combined point cloud data. The bitstream includes (i) first information indicating a maximum number of duplicated points that are included in each of the pieces of point cloud data and are three-dimensional points having same geometry information, and (ii) pieces of second information corresponding one-to-one with point indexes and each indicating which of the pieces of point cloud data three-dimensional points having a corresponding one of the point indexes belong to, the point indexes being indexes to which values a total number of which is equal to the maximum number are assigned, and being used for identifying duplicated points belonging to same point cloud data.

Abstract: A three-dimensional data encoding method includes: encoding first information of a first current node or second information 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: generating a bitmap indicating which of pieces of three-dimensional data a three-dimensional point belongs to, the three-dimensional point being included in a unit space; generating a conversion code using a look-up table and the bitmap generated; and generating encoded data including duplicated point information indicating a total number of three-dimensional points included in the unit space, and conversion code information indicating the conversion code. The generating of the conversion code includes: generating the conversion code from the bitmap when the total number of the three-dimensional points included in the unit space is less than or equal to a predetermined threshold value; and generating the conversion code from an inverted bitmap when the total number of the three-dimensional points included in the unit space is greater than the predetermined threshold value, the inverted bitmap being obtained by inverting 0 and 1 included in the bitmap.

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: generating a bitmap for combined three-dimensional data that is a combination of pieces of three-dimensional data, the bitmap indicating which of the pieces of three-dimensional data a three-dimensional point belongs to, the three-dimensional point being a three-dimensional point of the combined three-dimensional data and included in a unit space; generating a conversion code using the bitmap; and generating encoded data including duplicated point information indicating a total number of three-dimensional points included in the unit space, and conversion code information indicating the conversion code. Each of values of the bitmap corresponds to a combination of the conversion code and the total number of the three-dimensional points included in the unit space.

Abstract: A three-dimensional data encoding method includes: encoding subspaces obtained by dividing a current space which includes three-dimensional points, to generate pieces of encoded data; and generating a bitstream including the pieces of encoded data and first information indicating a shape of each of the subspaces.

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: generating a bitstream by encoding subspaces included in a current space in which three-dimensional points are included. The bitstream includes encoded data respectively corresponding to the subspaces. In the generating of the bitstream, a list of information about the subspaces is stored in first control information included in the bitstream. The subspaces are respectively associated with identifiers assigned to the subspaces, and the first control information is common to the encoded data. Each of the identifiers assigned to the subspaces respectively corresponding to the encoded data is stored in a header of a corresponding one of the encoded data.

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 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: 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 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: dividing three-dimensional points included in three-dimensional data into three-dimensional point sub-clouds including a first three-dimensional point sub-cloud and a second three-dimensional point sub-cloud; appending first information indicating a space of the first three-dimensional point sub-cloud to a header of the first three-dimensional point sub-cloud, and appending second information indicating a space of the second three-dimensional point sub-cloud to a header of the second three-dimensional point sub-cloud; and encoding the first three-dimensional point sub-cloud and the second three-dimensional point sub-cloud so that the first three-dimensional point sub-cloud and the second three-dimensional point sub-cloud are decodable independently of each other.