Apple Inc.
Significant coefficient flag encoding for point cloud attribute compression

Abstract:

A system comprises an encoder configured to compress attribute information for a point cloud and/or a decoder configured to decompress compressed attribute information for the point cloud. To compress the attribute information, a transform is applied to the attribute values to generate attribute coefficients/transformed attribute values. Points with attribute coefficients with a significant value are assigned a first binary flag value, while points with non-significant attribute coefficients are assigned a second binary flag value. A K.sup.th order exponential Golomb encoder or Golomb-Rice encoder is used to compress the run-length values, where separate states and associated contexts are maintained for funs of both the first and second binary values. A decoder uses a corresponding process to decode the compressed attribute information.