Image copyright protection scheme using Sobel technology and genetic algorithm

A novel scheme combining Sobel technology with genetic algorithm is proposed in this paper to protect image copyright. For the Sobel-based copyright protection schemes in the literatures, they use Sobel technology to detect the edge of the cover image, i.e. the copyright image. By using the kernels to calculate the edge directions of the cover image, the gradients of the cover image pixels can be measured. When the gradient is greater than some scaling factor, which is used to control the robustness of the watermark, its corresponding pixel is considered to be an edge pixel. Otherwise, it is not an edge pixel. Therefore, how to decide a proper value for scaling factor is important for Sobel-based copyright protection schemes. In this paper, the genetic algorithm is used to provide optimal value for scaling factor. Experimental results are shown to demonstrate the robustness of the proposed scheme.