Contrast signal-to-noise ratio for image quality assessment

Peak signal-to-noise ratio (PSNR) is commonly used as an objective quality metric in signal processing. However, PSNR correlates poorly with the subjective quality rating. In this paper, we propose a new metric using contrast signal-to-noise ratio (CSNR), which measures the ratio of the contrast information level of distorted signal to the contrast level of the error signal. The performance of the proposed method has been verified using a database of images compressed with JPEG and JPEG 2000. The results show that it can achieve very good correlation with the subjective mean opinion scores in terms of prediction accuracy, monotonicity and consistency.