Comparison of perceptually uniform quantisation with average error minimisation in image transform coding

An alternative transform coder design criterion based on restricting the ma ximum perceptual error of each coefficient is proposed. This perceptually u niform quantisation of the transform domain ensures that the perceptual err or will be below a certain limit regardless of the particular input image. The results show that the proposed criterion improves the subjective qualit y of the conventional average error criterion even if it is weighted with t he same perceptual metric.