ON BETWEEN-COEFFICIENT CONTRAST MASKING OF DCT BASIS FUNCTIONS 论文

摘要

In this paper we propose a simple and effective model of visual between-coefficient contrast masking of DCT basis functions based on a human visual system (HVS). The model operates with the values of DCT coefficients of 8x8 pixel block of an image. For each DCT coefficient of the block the model allows to calculate its maximal distortion that is not visible due to the between-coefficient masking. A modification of the PSNR is also described in this paper. The proposed metric, PSNR-HVS-M, takes into account the proposed model and the contrast sensitivity function (CSF). For efficiency analysis of the proposed model, a set of 18 test images with different effects of noise masking has been used. During experiments, 155 observers have sorted this set of test images in the order of their visual appearance comparing them to undistorted original. The new metric, PSNRHVS-M has outperformed other well-known reference based quality metrics and demonstrated high correlation with the results of subjective experiments (Spearman correlation is 0.984, Kendall correlation is 0.948).