Abstract: An image sharpness evaluation algorithm is proposed to evaluate the quality of image which has been optical filtered. The theory and process of this algorithm are analyzed, which attaches importance more on the influence of light intensity on the quality of image than other previous algorithms. Compared with other image sharpness evaluation algorithms, the experimental results show that this method overcomes the disadvantages of gradient square function, and would be effective in the evaluation not only in the automatic focusing field but the general images.

Key words: Evaluation, Image, Sharpness, Energy-Grayscale distribution, Light intensity, Auto-focusing