Real-time display camera communication system based on LED displays and smartphones

Area of Science:

• Optoelectronics
• Wireless Communication
• Human-Computer Interaction

Background:

• Visible light communication (VLC) offers dual functionality for display and data transmission.
• Existing systems face challenges with frame rate mismatches between high-refresh-rate displays and lower-rate cameras.
• Potential applications include information broadcasting and stealth advertising.

Purpose of the Study:

• To propose a real-time display-camera communication system using LED displays and smartphones.
• To address frame rate mismatch and symbol unsynchronization issues.
• To develop a system with efficient data extraction and minimal visual flicker.

Main Methods:

• Implemented an Alternate Bit-flipping Repeat Coding scheme for frame rate matching and synchronization.
• Developed fast image processing algorithms to reduce computational complexity.
• Utilized a 16x16 LED display (150 fps) and an Android smartphone (30 fps camera) with a custom app.

Main Results:

• Achieved a data transmission rate of 30 bps per LED display point.
• Demonstrated effective communication up to a distance of 80 cm.
• Real-time data reception on the smartphone took only 11.827 ms.

Conclusions:

• The proposed system effectively enables real-time visible light communication between LED displays and smartphones.
• The Alternate Bit-flipping Repeat Coding scheme successfully synchronizes disparate frame rates and eliminates perceivable flicker.
• The system demonstrates practical feasibility for applications requiring integrated display and invisible data transmission.