Jin Li, Principal Researcher & Manager
Compression Communication and Storage
Microsoft Research
Email: jinl@microsoft.com

R-D optimization

Fig. 1. Rate-distortion optimization for embedded coding.

This is the definitive work that established the methodology to achieve operational rate-distortion (R-D) optimality in embedded media coding.  It is shown that by allocating the available coding bits first to the cofficients with the steepest R-D slope, i.e., the largest distortion decrease per coding bit spent, the resultant coding bitstream can be truncated at any point and still maintain an optimal R-D performance.

The sub-bitplane scanning invented in this work became a key ingredient in modern image codecs,and was eventually incorporated into JPEG 2000. Prior, scalable coding scanned by bitplane. This work showed that significant additional coding gain can be realized by sequencing the transmission in sub-bitplanes, according to context, using a rate-distortion criterion.

  1. J. Li and S. Lei, "An embedded still image coder with rate-distortion optimization", IEEE Trans. on Image Processing, 1999.