A point cloud encoding method comprises: processing position information of a target point in a point cloud to obtain reconstruction information of the position information of the target point; obtaining an initial predicted value of attribute information of the target point according to the reconstruction information of the position information of the target point; filtering the initial predicted value of the attribute information of the target point using a Kalman filter algorithm to obtain a final predicted value of the attribute information of the target point; processing the attribute information of the target point in the point cloud to obtain a real value of the attribute information of the target point; obtaining a residual value of the attribute information of the target point according to the final predicted value and the real value of the attribute information of the target point; and encoding the residual value of the attribute information of the target point to obtain a bitstream.

A point cloud encoding method comprises: processing position information of a target point in a point cloud to obtain reconstruction information of the position information of the target point; obtaining an initial predicted value of attribute information of the target point according to the reconstruction information of the position information of the target point; filtering the initial predicted value of the attribute information of the target point using a Kalman filter algorithm to obtain a final predicted value of the attribute information of the target point; processing the attribute information of the target point in the point cloud to obtain a real value of the attribute information of the target point; obtaining a residual value of the attribute information of the target point according to the final predicted value and the real value of the attribute information of the target point; and encoding the residual value of the attribute information of the target point to obtain a bitstream.

Point cloud coding methods, an encoder, and a decoder are provided. The method includes the following. Morton codes for a point cloud are obtained according to geometry information of the point cloud after geometry decoding is completed and the geometry information is reconstructed. The point cloud is determined as an input point cloud of an iteration. Morton codes for an input point cloud of an i-th iteration are right shifted by K bits according to a number of points in the input point cloud of the i-th iteration, where K is a positive integer. A point is selected from points with a same value of Morton codes after right shifted by K bits. An i-th level of detail (LOD) layer is formed with the point selected. Color information is decoded according to the LOD layer.

A three-dimensional data encoding method includes: adding a first information item to a bitstream, the first information item indicating whether a duplicated point is available, the duplicated point representing, using a single node, position information items of two or more three-dimensional points having a same position information item in a prediction tree showing a reference relation in predictive encoding; and adding second information items to the bitstream when the first information item indicates that the duplicated point is available, the second information items each corresponding to a different one of nodes included in the prediction tree, and indicating a total number of one or more three-dimensional points included in the different one of the nodes.

A three-dimensional data encoding method includes: adding a first information item to a bitstream, the first information item indicating whether a duplicated point is available, the duplicated point representing, using a single node, position information items of two or more three-dimensional points having a same position information item in a prediction tree showing a reference relation in predictive encoding; and adding second information items to the bitstream when the first information item indicates that the duplicated point is available, the second information items each corresponding to a different one of nodes included in the prediction tree, and indicating a total number of one or more three-dimensional points included in the different one of the nodes.

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; and generates a bitstream including first information with respect to the prediction residual, second information indicating a bit count of the first information, and third information indicating a bit count of the second information.

Methods and devices for coding point clouds using direct coding mode to code coordinates of a point within a sub-volume associated with a current node instead of a pattern of occupancy for child nodes. Eligibility for use of direct coding is based on occupancy data from another node. If eligible, then a flag is represented in the bitstream to signal whether direct coding is applied to points in the sub-volume or not.

Methods and devices for coding point clouds using direct coding mode to code coordinates of a point within a sub-volume associated with a current node instead of a pattern of occupancy for child nodes. Eligibility for use of direct coding is based on occupancy data from another node. If eligible, then a flag is represented in the bitstream to signal whether direct coding is applied to points in the sub-volume or not.

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.

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.