A DWT-based Digital Video Watermarking Scheme with Error Cor(9)

Abstract. In this paper, a digital video watermarking algorithm is proposed. We present a novel DWT-based blind digital video watermarking scheme with scrambled watermark and error correcting code. Our scheme embeds different parts of a single watermark in

the one without the error correcting code. Moreover, the error correcting code is embedded in the audio channel. Frame dropping would not affect the audio channel much. Our scheme can take advantages of this to avoid destroying the information, and error correcting code can still be used to refine the watermark in improving the

NC value.

Fig. 9. NC values under frame dropping. From the experiment, we found that our scheme achieves better performance than the DWT-based scheme without scene-based watermarks.

3.2. Experiment with Frame Averaging and Statistical Analysis

Frame averaging and statistical analysis is another common attack to the video watermark. When attackers collect a number of watermarked frames, they can estimate the watermark by statistical averaging and remove it from the watermarked

video [17,18]. The scenario is shown in Fig. 10.

Fig. 10. Scenario of statistical averaging attack.

Our proposed scheme performs better because our scheme crops a watermark into pieces and embeds them into different frames, it making the watermarks resistant to attacks by frame averaging for the watermark extraction. The identical watermark used within a scene can prevent attackers from taking the advantage of motionless regions in successive frames and removing the watermark by comparing and averaging the frames statistically [19]. Independent watermarks used for successive, but different scenes can prevent attackers from colluding with frames from completely different scenes to extract the watermark.