Color image watermarking algorithm in NSCT-SVD based on SIFT

A color image watermarking algorithm is presented which is in non-subsampled contourlet transform and singular value decomposition(NSCT-SVD), by using scale-invariant features transform(SIFT)keypoints for image geometric correction. The algorithm uses the relations of the largest singular values of the NSCT low-frequency sub-blocks between gray and blue components, and embeds the watermark into the blue component, which has been en-crypted by chaos system. During the watermarking detection, using the stable SIFT keypoints of the NSCT low-fre-quency in red component to correct the geometric attacks in the watermarked image, the watermark synchronous in- formation is recovered and the watermark is extracted. Experimental results show that the proposed scheme is ro-bust to a wide range of image processing operations such as adding noise, filtering and compression and all kinds of geometric attacks.