Preventing Degradation of the Quality of Visual Information in Digital Signage and Image-Sensor-Based Visible Light Communication Systems

Abstract

In this paper, we propose an image-sensor-based visible light communication (IS-VLC) system that provides visual information in digital signage used for advertisements. One important issue of IS-VLC systems is the deterioration of visual information while transmitting the data information. Human eyes are sensitive to luminance but not to color difference; therefore, we propose the modulation of color difference. We evaluate the performance of the proposed system in terms of both the quality of visual information and communication quality of data information, and clarify the effectiveness of the proposed system.

Rotary LED Transmitter for Improving Data Transmission Rate of Image Sensor Communication

“…An image sensor (camera) converts light to electrical signals to be output as an image. Image sensor communication (ISC) is a scenario where a VLC system that uses an image sensor as a receiver is used [15]- [19]. ISC is often referred to as an optical camera communication (OCC).…”

Data signal demodulation based on machine learning for digital signage and image sensor based visible light communication

“…Several VLC schemes have been studied in which wireless communication is realized by superimposing data signals on displayed images of the digital signage and capturing them with an image sensor such as a smartphone camera. Related research, including a method of modulating the backlight of digital signage at high speed [1], modulation methods using frequency domain transformation [2,3], and modulation methods using color's chroma components that are difficult for human eyes to perceive [4,5], have been studied. These studies mainly focus on the processing of the transmitter side.…”

“…In digital watermarking, which is one of the techniques to superimpose data signals, the literature [6] utilized compression and decompression of an autoencoder and improved the accuracy of superimposition. In this paper, we apply machine learning to construct a new signal demodulation method for the VLC systems like [4,5] to achieve more accurate signal demodulation. As a first step, the proposed method demodulates data signals from received images using machine learning in which the communication channel simulates noise, blurring, and misalignment that may occur in received images.…”

Overlaying a motion video with data information for digital signage and image-sensor-based visible light communication systems

“…There are schemes to solve this issue [7,8,9], but these schemes have problems such as a low data rate or requirement of a special display. To resolve these problems, we proposed color differential modulation for the IS-VLC system and clarified the capability of the transmission of data information while avoiding the quality degradation of the visual information [10]. However, still images are used as visual information.…”

“…1 shows the model of the expanded IS-VLC system. In this section, we explain the conventional IS-VLC system proposed in [10]. The cell-position correction method and the noise elimination method is described in Sect.…”