Multipurpose Color Image Watermarking
Syed Asif Mahmood Gilani, Ioannis Kostopoulos, Athanassios N. Skodras · Int. J. Comput. Their Appl. · 2008
A novel approach for color image watermarking is proposed in this communication. The aim of the work is to combine robust and fragile watermarking in order to construct a multipurpose watermarking scheme. Watermarking methods are com- plementing each other such that under any circumstance at least one of them may survive and prove the identity of the owner or the authenticity of the image content. A robust watermark is embedded into the frequency domain; the watermark is made adaptive to the cover image. A semi-fragile watermark is embedded into the spatial domain of the color image. Authentication is achieved by means of embedding an approximation of the image into itself. Specifically, the luminance of the image is inserted into the three color channels, using a mapping function. For image copyright protection, higher robustness can be achieved whereas for image authentication tampered regions can be detected and reconstructed. Both of the goals are accomplished in an oblivious manner. Experimental verifications indicate that the proposed unified image watermarking is an appropriate choice.