BlackBerry Limited
Methods and devices for predictive point cloud attribute coding

Abstract:

Methods and devices for attribute coding for point clouds. In a top-down coding process a predicted geometry-weighted sum of attributes is determined for each occupied sub-volume of a volume based on a prediction operation that uses at least a geometry-weighted sum of attributes for the volume. The prediction operation involves up-sampling data from the preceding (parent) depth of the coding tree. The predicted geometry-weighted sums of attributes and corresponding original geometry-weighted sums of attributes are subtracted, in the attribute domain or in a transform domain to result in residual coefficients. The AC residual coefficients are coded in the bitstream. The transform used has a DC coefficient property, whereby the DC coefficient from transform of the geometry-weighted sums of attributes for the set of child sub-volumes is the geometry-weighted sum of attributes for the volume.