Enhancing robustness of digital watermarking against geometric attack based on fractal transform

This paper presents a digital image watermarking algorithm based on a fractal transform. It embeds the watermark in the spatial domain. The advantage of this algorithm is that it can successfully resist certain geometric attacks such as rotation, translation, flip, stretch, and zoom as well as normal signal processing operations such as JPEG compression. During detection, it does not need the original image to recover the watermark