Semi-fragile Watermarking and Authentication for Law Enforcement Applications

In this paper, a semi-fragile watermarking method for authentication of law enforcement images such as digital images captured at crime scenes and traffic enforcement situations is proposed using the pinned sine transform (PST). The watermarking system can localize the portions of image that have been tampered maliciously, with high accuracy. In particular, the watermarking scheme is very sensitive to any texture alteration in the watermarked images, which is crucial for crime scene image authentication. Simulation results are presented to demonstrate the effectiveness of the proposed method and its possible applications in the field of crime scene analysis. The proposed method of watermarking authentication could potentially prove useful when digital photographs are presented as evidence in the court of law.