Error masking method using moving picture electronic watermark of video

摘要

An error masking method using a moving picture electronic watermark. The method can reduce the operation quantity required for estimating motion vectors and acquire correct motion vectors even in case of high error ratio. The method has the conventional accuracy as the lowest accuracy and the upper layer compatibility with a general-purpose decoder. The digital moving picture signal is divided in area into a plurality of blocks or macro-blocks, each of which comprises NxN pixels and is motion-compensated. In obtaining or not obtaining a differential signal from one of a future or a past image, each block or macro-block is discrete-cosine transformed to issue a discrete cosine transform output. The discrete cosine transform output is quantized to obtain a quantized output. The quantized output is variable-length-encoded to obtain a bit stream. On the other hand, the motion vector is embedded in each of the blocks or macroblocks as electronic watermark information to make it possible to use the electronic watermark information for masking the errors during decoding.