关键词: 图像置乱, 置乱度, 差分图像, 互信息距离, image scrambling, scrambling degree, difference image

Abstract: The new image scrambling effect evaluation method based on mutual information distance of difference image was proposed. The new concept of mutual information distance based on mutual information was firstly proposed, and then the difference image of the original image and scrambled image was obtained by means of difference operation on two images. At last the mutual information of two difference images was computed and acted as the new criteria of image scrambling effect evaluation. Experimental results show that the proposed method is effective to describe the relation between the scrambling effect and the number of iterations in the scrambling techniques, which is largely consistent with human vision. For different images, when some transformation is used, this evaluation method can reflect to some extent the scrambling effects in each scrambling stage.

Key words: mutual information distance