中文摘要：

数字图像置乱程度是评价数字图像置乱算法的重要方面,对数字水印算法的研究也起到重要的指导作用,提出了一种新的图像置乱效果客观评价方法。该方法首先得到整幅置乱图像的特征向量,将置乱图像进行最优分块,得到每个图像块的特征向量,应用灰色关联分析对图像置乱程度进行度量。该方法不仅反映了整幅置乱图像的全局特征,还反映了图像的局部特征。实验结果表明,该算法与视觉上的主观评价结果基本一致,且适用于各种类型的加密图像。

英文摘要：

Digital image scrambling degree is one of the most important aspects of evaluating digital image scrambling algorithm,it has significant effects on the research of digital watermark algorithm.A quantitative metric is proposed to objectively evaluate the quality of image scrambling degree.The scrambled image is divided into several blocks in order to obtain the several blocks feature matrix.After,we could get the image scrambling degree by calculating grey relation degree between the reference sequence which is obtained by the particular image block and the comparatives sequence which is constructed by the several blocks.The results of the experiment have suggested that the digital image scrambling degree evaluation method is the same as all of sorts image encrypting.The resulting digital image scrambling degree is accordant with visual subjective evaluation,it would not differ a lot for the sake of the changing of its former image as well.