Method and apparatus for inter-channel prediction and transform for point-cloud attribute coding

An apparatus for interframe point cloud attribute decoding of video data, the apparatus comprising:

• at least one memory configured to store computer program code;
• and
• at least one processor configured to access the at least one memory and operate according to the computer program code, the computer program code comprising:
• first obtaining code configured to cause the at least one processor to obtain a first reconstructed residual;
• second obtaining code configured to cause the at least one processor to obtain a quantization index of a second reconstructed residual;
• third obtaining code configured to cause the at least one processor to obtain the second reconstructed residual, based on the obtained quantization index of the second reconstructed residual and the obtained first reconstructed residual;
• and
• fourth obtaining code configured to cause the at least one processor to obtain a color attribute of a point of a point cloud by decoding the obtained second reconstructed residual or decoding a transform residual based on the obtained second reconstructed residual,
• wherein the first reconstructed residual and the second reconstructed residual are each a reconstructed residual of a respective channel of the color attribute.

A non-transitory computer-readable storage medium storing instructions that cause at least one processor to:

• obtain a first reconstructed residual from video data;
• obtain a quantization index of a second reconstructed residual;
• obtain the second reconstructed residual from the video data, based on the obtained quantization index of the second reconstructed residual and the obtained first reconstructed residual;
• and
• obtain a color attribute of a point of a point cloud by decoding the obtained second reconstructed residual or decoding a transform residual based on the obtained second reconstructed residual,
• wherein the first reconstructed residual and the second reconstructed residual are each a reconstructed residual of a respective channel of the color attribute.