AN EVALUATION OF IMAGE QUALITY METRICS

Many metrics have been proposed, over a period of thirty years, which Rye able to predict image quality in the form of single numbers. These metrics reduce a number of physical measurements to single values for predictions of perceptions of the quality of many different types of images from statistical evaluations by panels of observers. One proble m concerned with the determination of any metric is which eye modulati on transfer function (contrast sensitivity function, CSF) to use. It i s only since 1992 that a physical model for determining the CSF of the eye has been provided which enables a standard CSF to be calculated f or varying viewing conditions. This paper reviews image quality metric s for sharpness and noise both independently and in combination.