Image-compression-related contrast-masking measurements
Marcus J. Nadenau, J. Reichel · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2000
Models of human vision can be efficiently exploited to improve the visual quality of image compression schemes. Most of the psycho-visual experiments documented in literature use very basic test patterns to analyze specific low-level vision effects. More complex patterns of real world images and strong constrains of an image compression scheme result in a very rough mapping of this psycho-visual data to the real system. So it is no longer guaranteed that the predicted visibility of the distortions is correct. In this paper we present an experiment strongly linked to wavelet-based image compression. It evaluates the effect of contrast and entropy masking based on complex images of natural scenery. The test images were reconstructed from a wavelet-decomposition where the wavelet coefficients were quantized at specific locations. The visibility of these distortions is influenced in a first order by the contrast masking effect and in a second order by the complexity of the affected image sub-region. With the collected test data some models are compared in terms of prediction performance.