AN SVD ORIENTED WATERMARK EMBEDDING SCHEME WITH HIGH QUALITIES FOR THE RESTORED IMAGES
Chin‐Chen Chang, Chia‐Chen Lin, Yih-Shin Hu · 2007
Abstract. Considering Chang et al.’s SVD-based watermarking scheme, which successfully embeds watermarks into images, and its hidden watermarks can resist various attacks. In this paper, we further extend their idea so that the hidden watermarks can be removed to provide authorized users better image quality for later usage after the ownership of purchased images has been verified. To achieve our objective, we modify their embedding strategy, and the extra information required for later restoration is embedded into the least important non-zero coefficients of the S matrices in the image. Experimental results confirm that our scheme not only provides good image quality of watermarked images but also successfully restores images with high restoration quality.