Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
745000 | Optics and Lasers in Engineering | 2011 | 9 Pages |
A watermarking technique, with a Computer Generated Hologram (CGH) coding system of the mark, is introduced and tested. The CGH watermarking can be used to authenticate parts of the original image. The hologram of the mark is embedded in the spatial domain by a blind additive embedding technique. The use of holography allows authenticating cuts of the original image, is the major novelty of this paper. The proposed methodology is characterized as an authentication technique, since it does not rely on the original image to decide whether the watermarked image has been altered or not and at the same time it is able to detect and localize any possible malicious change. Asymmetric cryptography is used to hide the hash information in an unambiguous way (non-repudiation property).
► The paper studies the potentiality of a CGH to authenticate parts of an image. ► The CGH is able to detect any manipulation, changing the visual content of the cover. ► The method has the advantage to be robust to cuts of the watermarked image.