Digital Image Watermarking using

Walsh-Coded Hand-Written Signatures

Amani Mohammed Bin Sewaif

Etisalat Internet & e-solutions

In recent years there has been a significant increase in the distribution of images in digital format. The ease in which such images can be copied and modified has created a pressing need for the development of copyright protection methods.

In digital image watermarking, copyright protection information is embedded in the image in the form of a watermark. The image must not be visibly degraded by the presence of this watermark. Another main requirement of watermarking for copyright protection application is its robustness. Thus, the watermark must be resistant to unauthorized detection and decoding.

There are many digital image watermarking techniques reported in the literature. We have developed algorithm using Walsh function to improve the robustness of digital image watermarking techniques. In the proposed methods, Walsh functions are used to encode the watermark, which is a handwritten signature before embedding it in the original image. The effect of changing the length of Walsh functions is also investigated. The results indicate that the use of Walsh functions results in improved robustness against JPEG attacks. Further, increasing the length of the Walsh function results in more robustness.