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.
Relation:
International Journal of Innovative Computing, Information and Control 3(3): 1-12
