<title>Progressive analysis-based perceptually transparent coder for still images</title>

Abstract

The encoding of images at high quality is important i n a n umber of applications. We h a ve d e v eloped an approach to coding that produces no visible degradation and that we denote as perceptually transparent. S u c h a technique achieves a modest compression, but still signi cantly higher than error free codes. Maintaining image quality is not important in the early stages of a progressive s c heme, when only a reduced resolution preview is needed. In this paper, we describe a new method for the progressive transmission of high quality still images, that e ciently uses the lower resolution images in the encoding process. Analysis based interpolation is used to estimate the higher resolution image, and reduces the incremental information transmitted at each step. This methodology for high quality image compression is also aimed at obtaining a compressed image of higher perceived quality that the original.

Application of inhomogeneous diffusion to image and video coding

“…In a perceptually transparent scheme based on a differential quantization based approach, the adaptive noise reduction was shown to providea 13% to 14% decrease in bit rate, averaged over all images [3]. The compression gain of perceptually transparent coding over JPEG-DPCM was slightly over 50%, allowing the compression of an image by an additional factor of two, while not introducing visible errors.…”