The use of digital cameras and camcorders in prohibited areas presents a growing problem. Piracy in the movie theaters results in huge revenue loss to the motion picture industry every year, but still image and video capture may present even a bigger threat if performed in high-security locations. While several attempts are being made to address this issue, an effective solution is yet to be found. We propose to approach this problem using a very commonly observed optical phenomenon. Cameras and camcorders use CCD and CMOS sensors, which include a number of photosensitive elements/pixels arranged in a certain fashion. Those are photosites in CCD sensors and semiconductor elements in CMOS sensors. They are known to reflect a small fraction of incident light, but could also act as a diffraction grating, resulting in the optical response that could be utilized to identify the presence of such a sensor. A laser-based detection system is proposed that accounts for the elements in the optical train of the camera, as well as the eye-safety of the people who could be exposed to optical beam radiation. This paper presents preliminary experimental data, as well as the proof-of-concept simulation results.

Date Published: 15 April 2008
PDF: 8 pages
Proc. SPIE 6945, Optics and Photonics in Global Homeland Security IV, 69451L (15 April 2008); doi: 10.1117/12.780923

Published in SPIE Proceedings Vol. 6945:
Optics and Photonics in Global Homeland Security IV
Craig S. Halvorson; Daniel Lehrfeld; Theodore T. Saito, Editor(s)