Rate-Distortion Optimized Wavelet-based Irregular Mesh Coding

This work investigates the optimization of mesh quality at lossy rates for a lossless scalable wavelet-based irregular mesh codec. Whereas previously proposed wavelet-based irregular mesh codecs offer coarse-grain resolution scalability, in this paper we propose a coding scheme which enables fine-grain quality scalability. This is done by avoiding the use of geometric data in the encoding process, which reduces dependencies within the data stream and allows for an unrestricted storage and transmission order of wavelet subband bitplanes and connectivity information. This in turn allows us to perform rate-distortion optimization, whereby the subband bitplanes to be encoded are determined by minimizing distortion subject to an overall target bitrate. Experimental results show that the proposed coding approach offers fine-grain quality scalability, achieves optimality in rate-distortion sense and improves compression performance over the state of the art.