The video watermarking technique based on discrete wavelet transform

With the growth of multimedia systems in distributed environments, the research of multimedia security as well as multimedia copyright protection becomes an important issue. As a potential and effective way to solve this problem, digital watermarking becomes a very active research area of signal and information processing. In this paper a wavelet-based video object watermark algorithm is proposed to work with MPEG-4 streams. First of all, object watermarking should be dealt with by modifying some Discrete Wavelet Transform (DWT) coefficients of the video objects extracted from each frame of the video sequence. Second, the possibility to identify the presence of watermarked objects also should be granted after the video sequence has been encoded in another format, at the same time experimental results demonstrate that the proposed watermarking scheme is robust to resist some unintentional and intentional attacks such as cropping, adding noise, filtering, and so on.