Study of an objective method of evaluating the color image reproduction from CRT to printer

摘要

It is necessary for evaluating the color reproduction from CRT image to printer image. However, the process of evaluation is difficult. This paper describes an approximate, but very simple and objective method of evaluating the color reproduction from CRT to printer by employing a scanner. The process is as follows: (1)an experimental image on a CRT, witch contains 1301 color patches with size 6x6mm~2; (2)the printed image was scanned by a scanner; (3)segmenting the scanned image for finding each color patch, then calculating average values of RGB for each patch; (4)calculating color difference between scanned image and original CRT image for each patch. Average difference may show approximately the color difference between a CRT image and the printed image. This method is based on a fact: color reproduction from CRT to printer is worse than from printed image to the scanned image. In our experiments, average CIE 1976Lu~*v~* color difference between the printed image and the CRT image is 10.9 units, but average color difference between the scanned image and the printed image is less than 4 units. Experiments show that the result of evaluation by this method is consistent with one by observers visually.