Comparative assessment of semifragile watermarking techniques
Oezguer Ekici, Barış Coşkun, Umut Naci, Bülent Sankur · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2001
Semi-fragile watermarking techniques aim to prevent tampering and fraudulent use of modified images. A semi-fragile watermark monitors the integrity of the content of the image but not its exact representation. Thus the watermark is designed so that if the content of the image has not been tampered with, and so long as the correct key is known and the image ha sufficiently high quality, the integrity is proven. However if some parts of the image is replaced by someone who does not possess the key, the watermark information will not be reliably detected, which can be taken as evidence of forgery. In this paper we compare the performance of nine semi-fragile watermarking algorithms in terms of their miss probability under forgery attack, and in terms of false alarm probability under mild, hence non-malicious signal processing operations that preserve the content and quality of the image. We propose desiderata for semi-fragile watermarking algorithms and indicate the promising algorithms among existing ones.