基于Walsh变换的图像置乱程度评价方法

Image Scrambling Degree Evaluation Method Based on Walsh Transformation

图像的置乱变换在信息隐藏和数字水印中有广泛的应用,对图像置乱程度的评价是非常重要的,它能帮助判定用怎样的置乱变换和对图像进行多少次置乱,才能获得好的信息隐藏隐蔽性和鲁棒性。利用Walsh变换的能力集中特性,并考虑置乱程度应满足的性质,提出了基于Walsh变换的图像置乱程度评价方法,实验表明所给出的评价方法能较好地刻划图像的置乱程度,与人的主观评价更接近。

In the context of information hiding and digital watermarking, it is of major importance to evaluate the image scrambling degree (ISD). It is helpful to decide what kind of transformation to be selected to scramble an image and how far to scramble it in order to obtain the best imperceptibility and robustness. To present a new metric for objectively assessing the ISD. The method utilizes the performance of energy concentration of Walsh transformation and takes into account the characteristics that a good ISD measurement method should be contented. Experimental results show that the proposed method is effective to assess the ISD, which correlates well with subjective assessment.