A novel human face watermarking scheme is proposed in this paper, providing copyright protection of semantic content. To achieve this goal, skin detection is initially performed using a skin filter which relies on color information and then face extraction is achieved using a combination of a morphological filter and a human face template. An invariant watermark is then designed and tested against attacks using invariant Zernike moments. The proposed algorithm has the advantages of being robust, computationally efficient and overheads transmitted to the decoder side are very low. Performance of the proposed human face watermarking system is tested under various signal distortions such as JPEG lossy compression, blurring, filtering and cropping. Experimental results on real life images indicate the efficiency and robustness of the proposed scheme.