Digital watermarking for color video using a nonlinear filter in detection process

A new watermarking method for color video, using a nonlinear digital filter, is proposed. This method is based on Haitsma and Zhao´s methods which embed watermark signals into the luminance mean series, but newly introduce a nonlinear digital filter, named a component separating filter (CS filter), in the detecting process to improve the detection performance. The CS filter can effectively extract the small-amplitude watermark signals on the mean series without being affected by an abrupt shot change. Moreover, it is shown that higher performance is realized by embedding into the color difference signal instead of the luminance. Computer simulations verify its performance.