Robust watermark detection against D-A/A-D conversion for digital cinema using local auto-correlation function

In this paper, we propose a blind watermark detection scheme for digital cinema which is robust against D-A/A-D conversion attack. D-A/A-D conversion attack commonly happens during capturing cinema with a camera and is composed of various geometrical distortions as well as signal processing distortions. In many video applications, geometric distortions have been compensated by utilizing auto-correlation function (ACF). Since the ACF cannot resist projective transform but affine transform, we present a robust watermark detection scheme utilizing local auto-correlation function (LACF) with a mathematical model. Also, we suggest a way to design watermark pattern to improve performance of the LACF. We demonstrate robustness of the presented scheme against D-A/A- D conversion attacks for digital cinema as well as common video processing attacks.