基于灰度均匀性的图像置乱程度盲评价算法

针对图像置乱程度评价问题提出以每个点为中心的区域灰度差均值作为图像置乱程度评价方法。算法首先针对理想置乱变换定义只适用于位置置乱的问题对其进行修改,使其也可以适用于包括像素置乱在内的所有置乱过程,并在此基础上考虑到各灰度值分布的均匀性,建立新的无需原图参与的图像置乱程度评价公式。实验仿真结果表明,该方法可以较好地衡量位置置乱图像或灰度置乱图像的置乱程度,与人的直观视觉评价吻合。

An Evaluation Algorithm for Image Scrambling Degree Based on Gray-uniformity

For image scrambling degree evaluation,this paper proposes a new method that each point as the center of the region to calculate the mean gray level.First it modifies the existing definition of ideal scrambling,which only applicable to the position scrambling,so that it can also be applied to the pixel scrambling.And on this basis,taking into account the uniformity of gray value,this paper proposes a new image scrambling degree evaluation formula without original image in the evaluation process.Experimental results show that the formula can effectively measure the degree of image scrambling,more consistent with people＇s intuitive visual.