pGBbBShift: Method for Introducing Perceptual Criteria to Region of Interest Coding

Abstract

This work describes a perceptual method (pGBbBShift) for coding of Region of Interest (ROI) areas. It introduces perceptual criteria to the pGBbBShift method when bit planes of ROI and background areas are shifted. This additional feature is intended for balancing perceptual importance of some coefficients regardless their numerical importance. Perceptual criteria are applied using the CIWaM, which is a low-level computational model that reproduces color perception in the Human Visual System. Results show that there is no perceptual difference at ROI between the MaxShift method and pGBbBShift and, at the same time, perceptual quality of the entire image is improved when using pGBbBShift. Furthermore, when pGBbBShift method is applied to Hi-SET coder and it is compared against MaxShift method applied to both the JPEG2000 standard and the Hi-SET, the images coded by the combination pGBbBShift-Hi-SET get the best results when the overall perceptual image quality is estimated. The pGBbBShift method is a generalized algorithm that can be applied to other Wavelet based image compression algorithms such as JPEG2000, SPIHT or SPECK.