Display Field Communication: Fundamental Design and Performance Analysis

The prevalence of cameras in consumer electric devices has led not only to many visual-sensing applications, but also potential use of cameras for communication purposes. With the increasing interest in optical camera communication technology and quick response codes, the display-to-camera (D2C) link has become a valuable side channel in ubiquitous computing environments. This paper proposes a new concept of display field communication (DFC), where the image on the electronic display is a transmitter and the camera is a receiver, meaning that data can be transmitted via the D2C links and image sequences can be displayed for their original purpose without serious visible artifacts. Because the proposed scheme embeds data at a designated spectral band, the hidden data do not reveal itself through normal displays and can only be revealed via the proposed decoding process. To observe the practical performance of the proposed DFC, the geometric distortion based on the various vision transformation parameters was considered and its effects on the communication performance according to the spectral bands were addressed. The simulation results showed that the maximum achievable data rate of approximately 9.5 kbps could be achieved for all perspective parameter cases when a gray-scale image size of 256 $\times$ 256 was used for embedding data, consisting of eight individual information vectors with their elements of 16-QAM modulated data. The proposed DFC algorithm showed satisfactory performance, providing a high data rate in the D2C communication link while the data embedded on the images was unobtrusive to the human eye.