A robust watermarking scheme based on Non-Subsampled Contourlet Transform

In this paper, a robust blind watermarking scheme is proposed based on Non-Subsampled Contourlet Transform (NSCT) and Singular Value Decomposition (SVD). NSCT keeps the scale of the original image and has better performance than other wavelets in image denoising and enhancement applications. Thus, its coarse subband is more robust to common image processing attacks and suitable for embedding watermarks. Due to its redundancy, we need another DWT or Contourlet Transform (CT) before SVD. Watermark bits can be embedded by adjusting the most significant singular values of each block. The experiment results show that this watermarking scheme has good robustness and invisibility.