Rate-distortion optimizations for region and object based wavelet video coding

This paper provides rate-distortion optimizations for both region- and object-based video encoding with a motion-compensated wavelet coder. The rate-distortion optimization which jointly selects all coding parameters for a frame is first applied to single video object plane (SVOP) coding via the Lagrange multiplier method. The optimal bit allocation for multiple regions of interest (MROI) coding is then achieved using a weighted Lagrange multiplier technique. Finally, the generalized R-D optimization for multiple video object plane (MVOP) coding is realized with the weighted technique by including special handling of object boundary blocks, which provides the additional capability of object scalability. The weights allow direct selection of relative distortions in the different regions or object planes, and simulations on MPEG-4 test sequences demonstrate the desired inhomogeneity in reconstruction quality.