Abstract
A new objective image quality evaluation method for image noise has been developed. Its metrics are based on the output responses from a cooperative human vision model which can theoretically simulate accommodative responses and various kinds of perceptual responses. In order to examine the effectiveness of the proposed evaluation method, it is applied to noise evaluation for the copies of uniform density patch images that are made by using three kinds of digital color copying machines. The following results were obtained: (1)the vision model theoretically predicted how the human vision system responded to the patch images' noise at every viewpoint; (2)the mean-square-log error of the vision model's evaluation function value correlated closely with the psychological image noise score for the patch images (absolute correlation coefficient>0.96). These results suggest that the proposed method is effective as an objective evaluation method for image noise and that perceptual responses in the subjective evaluation process are appropriately reflected in its metrics.
