图像置乱度评估的层次分析法

目的：针对目前置乱度评估算法对同一图像置乱算法的评价结果存在多变性，对多个置乱算法不能同时评估的问题，本文提出基于层次分析法的图像置乱评估算法。方法：首先，计算置乱矩阵元素分布的均匀性和随机性程度，获得置乱像素位置分布的属性值，保证了同一置乱算法置乱度的恒定性。然后应用层次分析法，实现置乱度二维属性的整合和多个置乱算法的同时评估。结果：实验结果表明，该算法得到的置乱度只与置乱算法本身和置乱迭代次数相关，和置乱对象无关，结果具有稳定性和有效性，同时算法可给出任意数目置乱算法的置乱度排序。结论：总之，建议算法实现了客观、公平、高效的图像置乱度评估，不仅有利于信息隐藏领域设计者方便快速选择合适的置乱算法，同时也为置乱算法的开发提供了有力的反馈工具。

Image scrambling degree evaluation based on analytic hierarchy process

Objective: At present, the algorithm of image scrambling degree evaluation has two problems. One is the instability of evaluation result for the same scrambling algorithm, the other is impossible to evaluate many scrambling algorithms at the same time. In order to solve these two problems, a new evaluation algorithm for image scrambling is proposed based on analytic hierarchy process. Method: At first, uniformity and randomness of scrambling matrix element distribution is calculated, thus, attribution values of scrambling pixels position distribution is acquired, the stability of scrambling degree is guaranteed. Then, by applying analytic hierarchy process, the integration of two dimensional attribution of scrambling degree and evaluation at the same time for many scrambling algorithms are implemented. Result: Experiment results show that the scrambling degree of scrambling algorithm is of stability and validity, which only relates with the algorithm itself and iteration number of scrambling and has nothing to do with scrambling object. Meanwhile, the sorting of scrambling degrees for any number scrambling algorithms is also established. Conclusion: To sum up, the proposed algorithm has the feature of objective, fair, efficiency, which not only favors fast choosing suitable scrambling algorithm for the designer in information hiding field, but also provides powerful feedback tool for the development of scrambling algorithm.