Transmission and watermarking of video and images

摘要

Methods for embedding and recovering a secure watermark in an encoded video sequence. The video sequence includes intra-coded frames interspersed by predicted frames, wherein the video sequence uses at least one intermittent forced intra refresh block within a sequence of predicted frames. The method includes the step of assigning a meaning (150, 180) to said at least one intermittent forced intra refresh macro block such that said forced intra refresh macro block meaning acts as a watermark. The watermark meaning may relate to the advancing or retarding of an expected intra refresh macro block. The method may also include a step of resolving an ambiguity caused by a naturally occuring intra macro-block.