Adaptive water marking

The watermark is an important protection and identification technique that allows an invisible mark to be placed on top of normal information such as bank note, ID card, magnetic card and valuable documents. Watermarking techniques have been developed to protect digital images against illegal reproduction and illegal modifications when visibility to users is required. Here, we present a new adaptive watermarking algorithm. The adaptive watermark is generated from the image content and can be treated as a digital fingerprint of the image. As a transform based algorithm is used to encode the information in the histogram domain the proposed watermark is robust enough against any degradation, hacking and attack.