Characterization of difference detection thresholds in AWGN-degraded images by using full reference metrics

This paper addresses the use of full reference metrics in the characterization of perceptual difference in a pair of images, in which one of them is degraded by additive white Gaussian noise (AWGN). Conventional (SNR, PSNR, and CC) and perceptual (MSSIM, IFC, VIF, and C4) full reference metrics are considered. The subjective experiment, which upholds the presented results, has been carried out with approximately 120 human subjects, considering a test set of 60 images divided into 5 groups. The difference detection threshold is defined as the value for a given metric from which human subjects perceive the difference between the reference and test images. In this sense, the performed data analysis aims both to derive difference detection thresholds for each tested metric and to evaluate their consistency.