Fragile Watermarking for Color Image Authentication

In this paper, we describe a watermarking system for digital color image authentication. This work is an extension of the Wong´s work which is based on a Hash function to construct fragile watermarking system. The system is able to detect any change in the image even though it is minimal. Also the system indicates the regions where suffered alterations. In this system, YCrCb color space is used instead of RGB color space. Watermark extraction process can indicate presence of any kind of alteration in the color image, using extracted watermark image. Computer simulation results show authentication capacity of the proposed system, using different image modification, such as JPEG compression, noise contamination, photomontage, etc. Many fragile watermarking system are vulnerable to vector quantization (VQ) attacks, however the proposed watermarking system also show robustness of the system against VQ attacks.