Watermarking MPEG-4 2D Mesh Animation in Multiresolution Analysis

Although watermarking techniques have been successfully applied to natural images and videos, little progress is made in the area of graphics animation. In particular, the MPEG-4 dynamic 2D mesh that provides efficient coding for animated graphics data imposes several realistic constraints for watermarking. In this paper, we propose a robust watermarking technique for MPEG-4 2D mesh animation. A multiresolution analysis is applied to locate feature motions of the animated mesh. The watermark signal is inserted based on a spread-spectrum approach by perturbing the extracted feature motions. We have also incorporated a spatial-domain registration technique to restore geometrically transformed mesh data. A variety of attacks, including the affine transformation, smoothing, enhancement and attenuation, and random noise, are used to verify the robustness of the proposed system. Experimental results show that our watermarks can withstand the aforementioned attacks. We also compare the performance of several common integer-to-integer wavelet transforms under the proposed framework.