A new method for detection of watermarks in geometrically distorted images

The goal of this study is to investigate the performance of the watermarking scheme proposed in [1] for watermarked images distorted by geometrical attacks such as StirMark [2]. Although the geometric distortions are not visually noticeable, the watermark cannot be detected due to resulting high mean square error between the original and attacked images. In order to extract the watermark from distorted images, the effects of these attacks must be minimized. This work focuses on the recovery of an attacked image using a reliable distortion estimation. The performance test is studied for several images attacked by StirMark. The proposed algorithm is shown to reduce false alarm probability in detection of the watermark from about 0.005 for (for StirMarked images) to less than 10(-50).