‘Window of visibility’ inspired security lighting system
This paper introduces a new information display system that can prevent the on-screen contents from being taken by cameras or camcorders without sacrificing visual qualities. The system is designed based on the idea of temporal psychovisual modulation (TPVM) with guidance from the concept of ‘window of visibility (WoV)’. TPVM utilizes the redundancy (in terms of spatiotemporal resolutions and etc.) of modern display devices over those perception limits of the human visual system (HVS). The WoV theory asserts that the perceivable spatiotemporal frequency of the HVS is different from that of those cameras. Therefore, using a properly measured or estimated WoV we can determine how to select or design the display devices and contents to achieve the goal of security protection, i.e. preventing on-screen contents from being recorded by imaging devices, while not affecting the pictorial quality. We have built a prototype of WoV inspired TPVM security display system.