Experimental research on image demodulation for optical camera communication

Optical camera communication (OCC), as a rapidly developing emerging wireless optical imaging communication technology, has broad application prospects due to its low-cost and highly popular optical camera receiver. However, the received images have problems such as perspective distortion and tilt distortion, halo effect, and optical noise, making threshold decision-making in image processing difficult. Implementing an OCC system to improve data rate and transmission distance remains a problem. An image optimization demodulation scheme has been proposed. In the decoding process, the region of interest is first used to extract the image matrix to reduce the impact of halo effects. Detect for distortion in the imaging and correct it. We have designed an improved center/curround retinex image enhancement scheme based on fast scale adaptive bilateral texture filtering, which can efficiently eliminate the fluctuation of grayscale values both globally and locally. Then perform a simple threshold judgment. Use the stripe width of the received pixel for symbol judgment to complete subsequent demodulation and decoding. Obtain the original transmission data. Through experimental analysis, the improved center/surround retinex algorithm proposed in this paper solves the problem of fluctuations in grayscale values. Compared with other algorithms, whether with an increase in communication rate from 3.5 to 6.5 kbps or a change in communication distance, the algorithm proposed in this paper has the highest decoding efficiency, with an average decrease in bit error rate of about one order of magnitude and the best decoding performance.