Abstract: A three-dimensional data encoding method includes: generating a first predicted value for an item of position information of a first three-dimensional point included in point cloud data, using an item of position information of a reference three-dimensional point included in the point cloud data and angle information; calculating a first difference value between the item of position information of the first three-dimensional point and the first predicted value; and generating a bitstream including the first difference value and the angle information.

Abstract: An encoding device includes memory and a circuit accessible to the memory. In operation, the circuit: encodes first vertex information, second vertex information, and third vertex information into a bitstream, the first vertex information indicating a position of a first vertex of a first triangle, the second vertex information indicating a position of a second vertex of the first triangle, and the third vertex information indicating a position of a third vertex of the first triangle; and encodes angle information into the bitstream, the angle information indicating one or more angles used for identifying a position of a fourth vertex of a second triangle by reference to the first triangle, the second triangle being a triangle that shares a common side with the first triangle and is on the same place as the first triangle.

Abstract: A three-dimensional data encoding method includes: encoding, for each of three-dimensional points included in point cloud data, geometry information and one or more items of attribute information to generate a bitstream. In the encoding, a normal vector of each of the three-dimensional points is encoded as an item of attribute information included in the one or more items of attribute information of the three-dimensional point.

Abstract: A three-dimensional data encoding method includes: determining a first maximum bit count for encoded data obtained after encoding at least one of (i) a divisional data unit obtained when point cloud data indicating a three-dimensional point cloud is divided or (ii) a point cloud data unit of the point cloud data before the dividing; and generating a bitstream by encoding (i) items of divisional data obtained by dividing the point cloud data or (ii) the point cloud data before the dividing, to satisfy the first maximum bit count determined. The bitstream includes first bit count information indicating the first maximum bit count.

Abstract: A three-dimensional data encoding method includes: calculating coefficient values from items of attribute information of three-dimensional points; quantizing the coefficient values to generate quantization values; and generating a bitstream including the quantization values. One or more items of attribute information are classified, for each of three-dimensional spaces, into one of groups, the three-dimensional spaces (i) being included in a plurality of three-dimensional spaces, and (ii) including, among the three-dimensional points, three-dimensional points including the one or more items of attribute information.

Abstract: A three-dimensional data decoding method includes: obtaining three-dimensional space information including encoded three-dimensional points; calculating an angle formed by a line segment connecting a predetermined position in the three-dimensional space information and a first base point and a line segment connecting the first base point and a second base point different from the first base point; determining whether the angle calculated satisfies a predetermined condition; and decoding the encoded three-dimensional points included in the three-dimensional space information when the angle calculated is determined to satisfy the predetermined condition, and not decoding the encoded three-dimensional points included in the three-dimensional space information when the angle calculated is determined not to satisfy the predetermined condition.

Abstract: A three-dimensional data encoding method includes: generating a first predicted value for an item of position information of a first three-dimensional point included in point cloud data, using an item of position information of a reference three-dimensional point included in the point cloud data and angle information; calculating a first difference value between the item of position information of the first three-dimensional point and the first predicted value; and generating a bitstream including the first difference value and the angle information.

Abstract: An encoding device includes: memory; and a circuit. In operation, the circuit: when a first triangle satisfies a condition, performs a first process including a process of using the first triangle to derive a predicted value of a current vertex to be encoded of a second triangle; when the first triangle does not satisfy the condition, performs a second process including a process of using a third triangle different from the first triangle and the second triangle to derive the predicted value of the current vertex; and encodes the current vertex using the predicted value.

Abstract: A three-dimensional model generation method executed by an information processing device includes: obtaining a first three-dimensional model from a measuring device that emits an electromagnetic wave and obtains a reflected wave which is the electromagnetic wave reflected by a measurement target to thereby generate a first three-dimensional model including first position information indicating first three-dimensional positions in the measurement target; obtaining a multi-viewpoint image generated by one or more cameras shooting the measurement target from different positions; and generating a second three-dimensional model by enhancing the definition of the first three-dimensional model using the multi-viewpoint image.

Abstract: A three-dimensional data encoding method includes: encoding, for each of three-dimensional points included in point cloud data, geometry information and one or more items of attribute information to generate a bitstream. In the encoding, a normal vector of each of the three-dimensional points is encoded as an item of attribute information included in the one or more items of attribute information of the three-dimensional point.

Abstract: A three-dimensional data encoding method includes: determining a first maximum bit count for encoded data obtained after encoding at least one of (i) a divisional data unit obtained when point cloud data indicating a three-dimensional point cloud is divided or (ii) a point cloud data unit of the point cloud data before the dividing; and generating a bitstream by encoding (i) items of divisional data obtained by dividing the point cloud data or (ii) the point cloud data before the dividing, to satisfy the first maximum bit count determined. The bitstream includes first bit count information indicating the first maximum bit count.

Abstract: A three-dimensional data decoding method includes: obtaining three-dimensional space information including encoded three-dimensional points; calculating an angle formed by a line segment connecting a predetermined position in the three-dimensional space information and a first base point and a line segment connecting the first base point and a second base point different from the first base point; determining whether the angle calculated satisfies a predetermined condition; and decoding the encoded three-dimensional points included in the three-dimensional space information when the angle calculated is determined to satisfy the predetermined condition, and not decoding the encoded three-dimensional points included in the three-dimensional space information when the angle calculated is determined not to satisfy the predetermined condition.

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 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: 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: 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 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 of encoding three-dimensional points includes: calculating a predicted value of attribute information of a first three-dimensional point in a prediction mode, using one or more items of attribute information of one or more second three-dimensional points in the vicinity of the first three-dimensional point; calculating a prediction residual that is a difference between the attribute information of the first three-dimensional point and the predicted value; and generating a bitstream including the prediction residual and prediction mode information indicating the prediction mode.

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.