Toward a unified fidelity metric of still-coded images

The development of metrics for assessing the quality of compressed images has given rise to considerable effort and has led to a general layout of the perceptual metrics based on models of the human visual system. Instead of another comparative study of the global performance of these systems, we sought to perform an individual evaluation of the main visual model components in order to propose a unified fidelity metric with low complexity and high performance. Our effort has focused on the frequency selectivity of human vision, perceived contrast, masking effects, pooling, and visual attention. We used the correlation between the obtained fidelity measures and the subjective assessment scores to analyze the different configurations.