Image Watermarking Using Contourlet Transform |
A novelwatermarking algorithm using contour let transform. The contour let transformis preferred for watermarkingbecause of its ability to capture the directional edges and contours superiorto other transforms such as cosine transform, wavelet transform, etc. Watermark is encrypted and embedded into highfrequency directional sub and, which is obtained by performing contour let decomposition on the hostimage. The watermarked image has very good perceptual transparency. Watermarkextraction algorithm is anon-blind process, which makes use of original image as reference forretrieving the watermark. This algorithm is robust against cropping attacks and geometric attacks and also hassuperior Peak Signal to Noise Ratio (PSNR) for the watermarked image.