Adaptive watermark algorithm based fast curvelet transform

The curvelet transform is a new multi-scale analysis method which can be used to represent perfectly the curve edges of natural image. Robust image watermark algorithm should embed the watermark into the edges of image according to Human Visual System. In this paper, an adaptive image watermark algorithm in curvelet domain was proposed. Firstly, the original image was decomposed into curvelet coefficients using fast curvelet transform. Then the significant coefficient’s position of different scales and orientations was located by analyzing the properties of them. At last, an adaptive watermark algorithm was used to embed a binary image into the curvelet significant coefficients by using the different scaling factor. The experiments show that a trade-off between the robust and imperceptibility can be obtained.