位平面与Gray码相结合的图像置乱方法

针对数字图像的传输安全问题，提出一种将位平面分解与Gray码相结合的图像置乱方法。该方法首先将图像分解成8个位平面，通过位异或操作改变携带图像有用信息的高4位位平面的值，然后对得到的初步置乱图像的灰度值进行Gray码变换，进一步置乱图像，从而得到加密图像。初步实验结果显示，该方法置乱效果明显优于Arnold法、Hilbert法等现有置乱方法，且实现简单。

Image scrambling algorithm based on bit-plane and Gray code

Aiming at the safe problem of image transmission,this paper presents an image scrambling algorithm based on bitplane decomposition and Gray code.Firstly,the original image is decomposed into eight bitplanes,and then its four bitplanes possessing more useful information are changed via a bitwise exclusive or operator.Finally,Gray code transformation is employed to improve the scrambled effect.The experimental results show that the algorithm not only is superior to several existing methods,such as Arnold,Hilbert,MSB or chaos scheme,but also can be easily implemented.