A Security Lighting System Based On Temporal Psychoviusal Modulation

Information display technologies have played an indispensable role in the advancement of human civilization.The ever-presence,great variety and continuously increasing sophistication of optoelectronic displays profoundly shape the ways we learn,work,communicate,and how entertain and even how we socially behave.In the age of multimedia technologies and information,the increasing importance of information security has become a hot spot in research and development.This paper puts forward the security lighting system based on temporal psychovisual modulation,which has a strongly interference on the images taken by the cameras without affecting the what the viewers can see.The main content is as follows,(1)Measuring the critical flicker fusion rate(CFF)Firstly,the critical flicker fusion frequency of the human vision system is measured.This paper reviews the characteristics of human visual system(HVS),the spatio-temporal sensitivity function,the definition of spatial frequency both in physics and vision science and the previous research on the frequency of critical flicker fusion.The critical flicker fusion rate is defined as the rate at which human perception cannot distinguish modulated light from a stable field.This rate varies with intensity and contrast,with the fastest variation in luminance one can detect at 50–90Hz,while recent research finds that humans perceive visual flicker artifacts at rates over 500 Hz when a display includes high frequency spatial edges.However,the results of the reported experiment were only carried out at a single spatial frequency.Therefore,a series experiments have been done to obtain the CFF for the particular visual stimuli using DLP projector with refresh rates up to more than 9000 Hz to display the image of different spatial frequency and contrast.The experimental results were surface fitting,which can predict the critical flicker fusion frequency of human visual system for such special visual stimuli under different spatial frequencies and contrasts.(2)Security lighting system based on TPVMBased on the display technology of TPVM,a new type of security lighting system is proposed,which can strongly interfere with the shooting of the viewing content without affecting the human eyes.Temporal psychoviusal modulation(TPVM)is a new paradigm of information display,which is conceived as an ingenious interplay of signal processing,optoelectronics,and psychophysics.The TPVM display paradigm,differs fundamentally in design principle,user experience,and cost effectiveness,from the head-mounted display(HMD)technology and all others while offering richer functionalities.Its core effect is achieved by the modulation of the atomic frame,so that human visual system perceive different visual perception with different modulation results,that is,the results of the fusion of multiple atomic frames in the human visual system.It is precisely because the last perceived picture is closely related to the perceptual characteristics of the human visual system,so that If the contents displayed using TPVM that are captured by an electronic device,under certain conditions,may be greatly different from the perception of the human eye.This can be explained by the concept of Window of Visibility,which characterize the range visible to the human visual system after converting visual content such as video to the frequency domain.In this paper,the concept is further extended,and it is proposed that the electronic photographing equipments,such as a camera,also can be treated as a type of visual system,and also has its unique Window of Visibility.After experiments,it is proved that the camera has a different Window of Visibility than the human visual system.In addition to this phenomenon,a new security lighting system is proposed.