2008 年 37 巻 5 号 p. 651-662
This paper proposes a novel data hiding method in the MPEG domain in which the image quality of the modified video is completely preserved to that of the original (compressed) video. To the best of our knowledge, there is no data hiding method that completely preserves the video quality during data embedding, and this method is the first attempt of its kind. This method is reversible where the modifications done during data embedding could be undone to restore the original video. This method is applicable not only to existing MPEG1/2 encoded videos but also to the encoding process of MPEG video from a sequence of raw pictures. The Reverse Zerorun Length (RZL) data representation scheme is proposed to exploit the statistics of macroblocks for achieving high embedding efficiency while trading off with payload. We theoretically analyze that RZL outperforms matrix encoding for both payload and embedding efficiency for this particular data hiding method. The problem of filesize increase during data embedding is addressed, and two independent solutions are proposed to suppress the filesize increase. Basic performance of this method is verified through experiments on various existing MPEG1 encoded videos.
