Using the fractal code to watermark images

We present a novel technique for the digital watermarking of still images based on fractal encoding and decoding. In general, a fractal coder exploits the spatial redundancy within the image by establishing a relationship between its different parts. We use this relationship to embed a watermark and use the invariability of the fractal parameters to retrieve the signature. The original unsigned image is not required for watermark extraction. Simulation results show the superior performance of our methods and demonstrate the robustness to such signal distortions as JPEG compression, low pass filtering, additive noise and scaling.