This paper proposed a method to improve the visual quality of low frequency watermarking methods, which are robust to various attacks which have clear visual artifact. I researched about low frequency watermarking methods for robustness against many attacks such as resizing and recompression required in contemporary video environments. In this paper, the problem of low frequency watermarking methods has been solved. It reduced the visual artifacts of the low frequency watermark much by applying a dithering technique. The experimental results show that the dithering method achieved better visual quality than low frequency watermarking methods without dithering while maintaining the robustness. It means that the method has good performance to reduce the visual artifacts of low frequency watermarking methods and does not worsen the merit of low frequency watermarking methods, robustness much.
