An Automatic Evaluation Method of Image Mattes

In image matting, several algorithms that produce highquality results have recently been proposed; however, certain parameters have to be manually determined in order to obtain favorable results, which requires significant user effort. In this paper, we propose a method of automatically evaluating alpha mattes based on either of the two criteria: mutual information or correlation coefficient between the matte and the image gradient fields, and selecting optimal parameter values. This drastically reduces the user effort required for tuning parameters in image matting. The experimental results using several matting algorithms for various images show that the automatically selected alpha mattes are similar (or the same) to the manually selected optimal ones.