Perceptual quality assessment of color images using adaptive signal representation

Perceptual image distortion measures can play a fundamental role in evaluating and optimizing imaging systems and image processing algorithms. Many existing measures are formulated to represent "just noticeable differences" (JNDs), as measured in psychophysical experiments on human subjects. But some image distortions, such as those arising from small changes in the intensity of the ambient illumination, are far more tolerable to human observers than those that disrupt the spatial structure of intensities and colors. Here, we introduce a framework in which we quantify these perceptual distortions in terms of "just intolerable differences" (JIDs). We first construct a set of spatio-chromatic basis functions to approximate (as a first-order Taylor series) a set of "non-structural" distortions that result from changes in lighting/imaging/viewing conditions. These basis functions are defined on local image patches, and are adaptive, in that they are computed ...

• Type: Conference
• Year: 2010
• Where: HVEI
• Authors: Umesh Rajashekar, Zhou Wang, Eero P. Simoncelli
• Keywords: Basis Function, Distortion, Emerging Technology, HVEI 2010, Image Distortions