A generalized Natural Preserving Transform watermarking technique

This paper discusses how digital image watermarking can be achieved using Natural Preserving Transforms NPT. The paper also proposes a general watermarking embedding technique, and describes a fast least squares technique for watermark extraction. Simulation results show that the quality of the watermarked image is very high. Besides, these results demonstrate the robustness of the proposed watermarking technique against cropping, compression and noise attacks.