Predictive geometry coding of point cloud

A method for decoding point cloud data, the method comprising:

• determining a first point of the point cloud data to be a first node of a first prediction tree branch of a prediction tree;
• determining that a first azimuth difference between the first point and a second point of the point cloud data is greater than a first azimuth threshold, wherein the first point and the second point comprise successive points in an order;
• based on the first azimuth difference being greater than the first azimuth threshold, determining the second point to be a second node of the first prediction tree branch;
• determining that a second azimuth difference between a third point of the point cloud data and a fourth point of the point cloud data is less than or equal to the first azimuth threshold, wherein the third point and the fourth point comprise successive points in the order and wherein the third point comprises a third node of the first prediction tree branch;
• based on the second azimuth difference being less than or equal to the first azimuth threshold, terminating the first prediction tree branch at the third point such that the third point comprises a leaf node of the first prediction tree branch and determine the fourth point to be a first node of a second prediction tree branch of the prediction tree;
• and
• decoding the point cloud data based on the prediction tree.

A device for encoding point cloud data, the device comprising:

• one or more memories configured to store the point cloud data;
• and
• one or more processors implemented in circuitry and communicatively coupled to the one or more memories, the one or more processors being configured to:
• determine a first point of the point cloud data to be a first node of a first prediction tree branch of a prediction tree;
• determine that a first azimuth difference between the first point and a second point of the point cloud data is greater than a first azimuth threshold, wherein the first point and the second point comprise successive points in an order;
• based on the first azimuth difference being greater than the first azimuth threshold, determine the second point to be a second node of the first prediction tree branch;
• determine that a second azimuth difference between a third point of the point cloud data and a fourth point of the point cloud data is less than or equal to the first azimuth threshold, wherein the third point and the fourth point comprise successive points in the order and wherein the third point comprises a third node of the first prediction tree branch;
• based on the second azimuth difference being less than or equal to the first azimuth threshold, terminate the first prediction tree branch at the third point such that the third point comprises a leaf node of the first prediction tree branch and determine the fourth point to be a first node of a second prediction tree branch of the prediction tree;
• and
• encode the point cloud data based on the prediction tree.