Investigation into preventing piracy based on the temporal perception difference between devices and humans using modulated projection light

The piracy of intellectual property rights and privacy through unauthorized capturing of images and videos has been increasing rapidly. We introduce a new methodology for preventing piracy, that utilizes a light source that emits specially modulated projection light to embed imperceptible watermark patterns in images and videos, thereby degrading their quality. The modulation ways of light source exploit the temporal perception difference between the human visual system (HVS) and the image sensor devices. We employed a model-driven approach to optimize the modulation ways of light source in order to effectively prevent piracy. We have also designed experiments to discuss the degradation of image quality at different factors and evaluate the effectiveness of the proposed method. Extensive objective evaluations under different scenarios demonstrated that our method can effectively prevent piracy on various smartphones. Subjective tests on volunteers demonstrated that the modulated light source appears to the HVS to be the same as a steady light source.