Proposal of a watermarking scheme using winding number and unneeded synchronism

This paper presents a new scheme for robust watermarking against general geometric distortions, such as rotation, scale, and translation. Some previous methods that are robust for geometric distortion need synchronism between embedded and detected locations. However, synchronism requires extensive calculations and does not resist radical distortions. We propose a watermarking scheme using a winding number, which is a topological invariant that is not changed by geometric distortions, and does not require synchronism.