Abstract:A novel video watermarking algorithm is proposed based on the hologram of the original watermark and optical flow. In the beginning, the key-flame is selected by the local optical flow. Then the hologram is embedded in the median-frequency coefficients in the DCT domain. The position of waterm ark and side information are adopted to retrieve the waterm ark without the original host image, so that the algorithm is secure. Numerical experiments show that the embedded waterm ark is robust to usual video manipulations, such as superposing frame cropping, noise, frame exchanging and MPEG compression and format exchanging.