Digital Image Encryption Algorithm Based on Improved Arnold Transform

Image scrambling is a widely applied in digital image watermark technology. Therefore, Arnold transform is often used, but its security is not enough because the form is the only and public. In this paper, an improved Arnold transform is present; it is realized in computer through proving. We can choose different transform coefficient and times in image scrambling, it is difficult to restore the original image after the transform because the transform coefficient is not the only, which can improve the efficiency of scrambling algorithm and watermarking security. An improved evaluation of the degree of scrambling is present in this paper. The experimental results demonstrate that the improved evaluation is more accurate measure than the original criterion in the degree of scrambling.