An ROI image coding based on switching wavelet transform

We propose a region-of-interest (ROI) image coding based on the switching wavelet transform. In order to relax the restriction for the allocation of information quantity between ROI and region-of-non-interest (non-ROI), we employ a wavelet transform with shorter length basis for ROI, and a longer length wavelet with better compression performance for non-ROI. Moreover, we present a method of allocation of information quantity for the switching wavelet that can control the ratio of the restored image quality for ROI to that for non-ROI under a given total information quantity. Our method can avoid information loss for non-ROI at lower bitrate in JPEG-2000, therefore subjective image quality for the whole of the restored image is improved, maintaining the quality of ROI to be higher than that of non-ROI.