  The state-of-the-art video-based point cloud compression scheme projects the
3D point cloud to 2D patch by patch and organizes the patches into frames to
compress them using the efficient video compression scheme. Such a scheme shows
a good trade-off between the number of points projected and the video
continuity to utilize the video compression scheme. However, some unoccupied
pixels between different patches are compressed using almost the same quality
with the occupied pixels, which will lead to the waste of lots of bits since
the unoccupied pixels are useless for the reconstructed point cloud. In this
paper, we propose to consider only the rate instead of the rate distortion cost
for the unoccupied pixels during the rate distortion optimization process. The
proposed scheme can be applied to both the geometry and attribute frames. The
experimental results show that the proposed algorithm can achieve an average of
11.9% and 15.4% bitrate savings for the geometry and attribute, respectively.
