关键词: 图像相似度, 结构相似度, 分水岭算法

Abstract: In order to realize the automation of image evaluation in all kinds of course and examination, and reflect the degree of difficulty of different content in one image, the image automatic evaluation program is designed. By combining the watershed algorithm with the Structural Similarity（SSIM） theory, a WSSIM algorithm for evaluating the degree of difficulty is proposed. A total of 3,173 samples are tested by randomly selecting from 5 actual experiments, which already have artificial evaluation results. By calculating the absolute error between the artificial evaluation and the system evaluation, the results show that：more than 63.75% of samples error is less than 1.5, while the maximum value can reach 74.26%. More than 84.41% of samples error value is less than 2.5, while the maximum value can reach 92.68%. The statistical results show that the results of system evaluation are in good agreement with manual evaluation, and the standard difference is less than manual evaluation. The average accuracy of WSSIM is 12.91% higher than that of SSIM. The experimental results show that the system is effective and can be run directly in the Windows 7 after compilation. It can help relevant institutions and grade examination to carry out automatic image marking.

Key words: image similarity, Structural Similarity（SSIM）, watershed algorithm