Functional Watermarking Algorithm Based on Contourlet Transform and ECC

User-defined functional watermarking algorithm was presented based on contourlet transform field and Ellipse Curve Cryptography（ECC） spatial field. First the edge and direction information of image was obtained by contourlet transform, the discrete functional watermarking was embedded into high frequency parts, and the embedding data was avoided to the image edge. ECC encrypts embedding coordinate’s series. Watermarking changes little original image because of less function data, and attends to zero watermarking algorithms. The results show that the algorithm is invisible to watermarking and also has enough robustness to noise and cropping attack.