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.