J. Yang’s scientific contributions

The present accuracy of CRT characterization is about 0.5ΔE* ab. In some experiments of measurement of color difference, color appearance, image appearance, contrast sensitivity function, accurate control color in small range around color centers is necessary. A method of color control in experiment is presented, which adopts the linear interpolation and takes into account the interaction of three channels in small range. With this method, the experimental results show that characterization accuracies are 0.14, 0.082, 0.103 for L*, a*, b* respectively, and 0.18, 0.18, 0.22 for three kinds of color differences of CIELAB, CIE94, CIEDE2000.

The performance of an image quality evaluation model can be improved by considering characteristics of the human visual system. The S-CIELAB model, which takes account of the spatial blurring by human visual system, is used to measure color difference between two color images. In this paper, it presents that the two parameters of objective evaluation of color image quality, color difference mean square error (CD-MSE) and color difference peak signal-to-noise ratio (CD-PSNR) based on the model of S-CIELAB. Objective experiments are conducted on three kinds of distorted images of JEPG2000, white Gaussian noise and transmission errors in JPEG2000 bitstream (total 180 images), compared with subjective evaluation of mean opinion score (MOS), and results show consistency between them.