A Novel Image Scrambling and Watermarking Scheme Based on Orbits of Arnold Transform

The conventional scrambling ways of Arnold transform are by disordering the pixel positions to get a totally visual difference from the original images. This paper proposes a new scheme to scramble the digital images. Different from the conventional schemes, we disorder the pixel positions by the orbit of the transform. By setting the initial position, one can get an orbit of the transform. Thanks to the chaotic characteristics, the orbit will generally fill the unit square; the points on the orbit have their corresponding order numbers which can be used to shuffle the image pixel positions. The scrambling procedure can be used to disorder the host image in watermarking scheme to enhance the robustness against attacks. Experimental results show that the proposed scheme yields good scrambling effects compared with the conventional ways. The watermarked images are robust against attacks as well.