Multiple arbitrary shape ROI coding with zerotree based wavelet coders

Region-base video coding schemes employed in MPEG-4 is also promising for still image coding applications where images contain a number of objects that can be encoded at different bit rates, such as compression of medical images for archiving and transmission. Motivated by this fact, in this paper, we investigate multi-region and multi-quality (MRMQ) coding based on zerotree wavelet coders. We present a novel scheme, which addresses the region size sensitivity problem in region-based coding. The proposed method outperforms the region of interest (ROI) coding unit of JPEG-2000, i.e., it is possible to save 0.3 bits per pixel to attain the same ROI/background rate-distortion performance with the proposed MRMQ coding scheme.