US 2020/0090373 A1 · ADAPTIVE SUBBAND CODING FOR LIFTING TRANSFORM

Abstract

Lifting is a transform designed for color compression of point clouds which is adopted in one of the MPEG test models. The performance of lifting is improved herein. All the lifting coefficients are first divided into several subbands based on their assigned weights, which indicate the level of importance of each coefficient. Then, for each subband, a set of three dead-zones are derived for the three color components. The dead-zones of Cb and Cr channels are typically larger than that of Luma channel. In the original lifting scheme, Chroma is not suppressed at all. In contrast, as described herein, the size of the dead-zone is increased for different color components, which means that more quality (and bandwidth) is able to be adaptively provided for luminance coefficients than chrominance coefficients.

Claims21

Dependent claims

A method programmed in a non-transitory memory of a device comprising:

multiplying a residual of a point cloud by a weight to generate a weighted residual;
quantizing the weighted residual to generate a quantized level;
and
dividing the quantized level by the weight to generate a reconstructed residual which is used for color compression of the point cloud.

1 more element

Dependencies are inferred from the claim text.

Adaptive subband coding for lifting transform

Life of this patent

Adaptive subband coding for lifting transform

Life of this patent

Abstract

Claims21