Digital Watermarking Based on Three-Dimensional Wavelet Transform for Video Data

Abstract

With the increment of digital media, multimedia technology and copyright protection have been the important issue. In this paper, an effective watermarking algorithm is proposed to protect copyright of video data. In the watermark embedding step, a three-dimensional discrete wavelet transform (3D DWT) is used to decompose original video data, because a pirate can easily extract the watermark by statistically comparing successive frames in case that the watermark is embedded in spatial doamin. The binary image is used as the watermark. It is changed into the video watermark by a two-dimensional (2D) pseudorandom permutation and the spread spectrum technique. The video watermark is embedded into the 3D DWT coefficients of the selected subbands. In the watermark extracting step, the embedded video watermark is detected by the similarity of the unit of subband and the final watermark image is extracted by a watermark decision rule and a reverse permutation. Experimental results show that the watermarked frames are subjectively indistinguishable from the original frames, plus the proposed video watermarking algorithm is sufficiently robust against various attacks.