Visible light communication using a digital camera and an LED flashlight

This paper presents an approach for optical communication via visible light using a focusable LED flashlight as the transmitting device and a digital camera as the receiver. One novelty of the approach is that the design can integrate generic off-the-shelf light source and camera components and is designed to work indoors under typical lighting conditions, i.e., overhead lighting and ambient daylight. The communication signal is transmitted as a sequence of (1,0) values that turn on/off the light source. A camera receives the signal by observing the presence/absence of the projected light spot on an intervening surface and converting this back into a (1,0) binary signal. The approach applies image processing techniques to compute the received signal from a recorded camera image.