Generalized Multiple ROI Prioritization in JPEG2000 for Natural Images

Every digital image has some spatial regions that are more important in some sense than others are. To provide higher reconstruction quality for the important region, Region of Interest (ROI) based compression methods are developed. In image compression, ROI coding allows to recover the ROI earlier than the rest of the image. JPEG2000 is an international standard for still image compression and provides an extensive set of features including ROI coding. The Maxshift and Implicit are the two ROI coding methods specified in JPEG2000 part-1. They use two different mechanisms, modifying wavelet coefficients, and ratedistortion optimization respectively. These methods have some advantages and disadvantages. The paper proposes a multiple region of interest prioritization coding method for JPEG 2000, to overcome the drawbacks of these methods. The proposed method, improve objective as well as subjective qualities, the Peak Signal to Noise Ratio (PSNR) and the Structural Similarity Index (SSIM) in the ROIs respectively. Keywords— EBCOT, JPEG2000, MAXSHIFT, Implicit, PCRD