基于Hilbert曲线的数字图像置乱方法研究

研究了基于Hilbert曲线的数字图像置乱方法 ,引入二个概念 :“重合度”和“Hilbert曲线的平移” ,利用Hilbert曲线平移 ,获得了更多新的置乱路径 ,并根据重合度变化图探讨了置乱变换的规律 ,以测试置乱变换的周期和拟周期。然后把基于Hilbert曲线的置乱方法推广到任意大小的图像。实验结果表明 :利用Hilbert路径进行置乱不仅具有非常大的置乱路径选择空间 ,而且具有很好的置乱效果和极大的置乱周期 ,具有较大的实用性。

Scrambling Research of Digital Image Based on Hilbert Curve

The thesis makes a study on the method of digital image scrambling based on Hilbert curve, two concepts are introduced in: "overlap ratio" and "Hilbert curve shifting". Shifting the Hilbert curve can get much more new paths for scrambling, and with the changing figure of the overlap ratio the rule of scrambling transformation is discussed in order to test the period and the quasi-period of the scrambling transformation. And then, the scrambling method is extended to be adapted for images of arbitrary size. Experimental results show that the scrambling based on Hilbert curve not only has lots of selections for scrambling path, but also has a good scrambling result and a large period, and it has great practicability.