A Synchronization Method for Temporal-Spatial Spread Spectrum Video Watermarking

Abstract

We propose a new synchronization recovery scheme for watermark detection in moving pictures. Since most proposals that have so far tried to recover synchronization of still images could hardly solve such problems as computational complexity, additional distortions, or difficulty of application to images with affine transformation involving aspect ratio changes or cropping, synchronization scheme for still images cannot be simply applied to synchronization recovery for moving pictures. We have solved these problems on former schemes by using temporal features of moving pictures. In our method, the Temporal-Spatial spread spectrum technique is used for synchronization recovery, that is, temporally spread watermark signal is embedded into each frame. In a detection phase, temporal synchronization is recovered first and the embedded watermark signal appears as a geometrical pattern with a formal feature in an integrated image of inverse spread frames. The feature is used for recovery of spatial synchronization. We verified that our scheme worked well in an experimental environment modeling illegal copying that included HD-SD down conversion and recording by an analog VCR. © 2005, The Institute of Image Electronics Engineers of Japan. All rights reserved.