Reversible data hiding scheme for the H.264/AVC codec

Very few reversible data hiding methods are proposed for compressed video and particularly for the H.264/AVC video codec, despite the importance of both of the watermarking reversibility criterion and the codec. The reversible watermarking techniques of images, when applied to the compressed video, can affect particularly the video quality and bitrate. Thus, to make these techniques applicable, the embedding capacity is usually reduced. Therefore an adaptation is necessary to improve the tradeoff between the embedding capacity, the visual quality and the bitrate of the watermarked video. In this paper, we investigate the possibility to introduce the DCT based reversible data hiding method, proposed initially for compressed images, to H.264/AVC codec. The embedding is applied during the encoding process, in the quantized DCT coefficients of I and P frames. To enhance the embedding capacity a mapping rule is used to embed three bits in one coefficient. Results show that exploiting the P frames improves considerably the video quality and the embedding capacity.