Method and apparatus to encode and decode two-dimension point clouds

A method of encoding a two-dimension point cloud in a bit stream, the method comprising:

• generating a matrix of two-dimension coordinates representative of an unfolded grid by mapping a regular grid according to a dense mapping operator;
• a dense mapping operator being a mapping operator optimizing the use of pixels of a frame for a point cloud;
• generating a frame of pixels by applying a mapping operator to the point cloud, said mapping operator being determined according to said matrix;
• and
• generating the bit stream by encoding said frame associated with said matrix of two-dimension coordinates representative of said unfolded grid in the bit stream.

A device comprising a memory associated with at least one processor configured to:

• obtain, from a bit stream, a frame of pixels and a matrix of two-dimension coordinates, representative of an unfolded grid, said data being associated with said frame;
• determine an un-mapping operator according to said matrix;
• and
• decode the point cloud by applying said un-mapping operator to said frame.

A device comprising a memory associated with at least one processor configured to:

• generate a matrix of two-dimension coordinates representative of an unfolded grid by mapping a regular grid according to a dense mapping operator;
• a dense mapping operator being a mapping operator optimizing the use of pixels of a frame for a point cloud;
• generate a frame of pixels by applying a mapping operator to the two-dimension point cloud, said mapping operator being determined according to said matrix;
• and
• generate a bit stream by encoding said frame associated with said matrix in the bit stream.

A stream carrying data representative of a two-dimension point cloud, wherein the data comprises:

• a first syntax element carrying a matrix of two-dimension coordinates representative of an unfolded grid generated by mapping a regular grid according to a dense mapping operator;
• a dense mapping operator being a mapping operator optimizing the use of pixels of a frame for a point cloud;
• and
• a second syntax element relative to at least one frame of pixels generated by applying a mapping operator to the two-dimension point cloud, said mapping operator being determined according to said matrix;
• wherein the matrix is associated with said at least one frame.