ABSTRACT
This chapter discusses a few popular contemporary perceptual coders which subscribe to the several classes of perceptual coding principles. Classical transform based coders performed excellently in reducing statistical redundancies. Incorporating properties of the human visual system to coding structures is seen as a beneficial step in enhancing the visual performance of image coders. While the Post Compression Rate-Distortion optimization offers a significant level of control as to the order in which bit-plane information is coded, it has one drawback with vision modeling. Test images are assessed on a continuous scale, categorized into five levels: excellent; good; fair; Poor and bad. The traditional approach to optimizing vision model parameters involves the measurement of the threshold response of human vision with synthetic test stimuli. The present adaptation of vision modeling for distortion assessment has been motivated by its successful application in the evaluation of blocking distortions and general quality of digital video.
