Abstract: A fragile watermarking algorithm applying to electronic police information processing system is proposed in this paper. First license plate is extracted as the embedded watermark from illegal driving automobile image and then was embedded in DCT domain; watermark was extracted without original image. MATLAB simulation results show that the proposed watermarking algorithm can be embedded in the illegal driving automobile image captured by electronic eye, and watermark can be exactly extracted under the conventional image processing such as noise addition & JPEG compression. When watermarked image is subjected to cropping and license plate content tampering attack, the extracted watermark is not clear enough, thus indicates the illegal driving automobile image was tampered.

Keywords: license plate extraction, fragile watermark, DCT transformation, content tempering