An Efficient and Portable LED Multispectral Imaging System and Its Application to Human Tongue Detection

LED illumination-based multispectral imaging has a fast switching ability, high cost-effectiveness, and a simple structure. It has been used in some applications, especially color recognition. In this paper, we introduce an efficient and portable LED multispectral imaging system for human tongue detection. The spatial pixels are categorized based on cosine similarity to reduce the optimization calculation times. Further, segment linear calibration is used to improve the recovery quality. Simulation results show that this method greatly improves the reconstruction speed and that recovered images maintain a high spatial and spectral quality. This LED multispectral imaging system captures images quickly and obtains multispectral images in a timely fashion. We also built a small prototype for human tongue detection in traditional Chinese medicine. The recovered spectra were used to calculate the tongue body color and fur color. By combining these with the spatial information, the fur distribution and fur thickness were analyzed. The results of this study verified the effectiveness of this LED multispectral imaging system. Further experiments will be undertaken for the quantitative analysis of tongue features. The study was approved by the Institutional Review Board (or Ethics Committee) of Shenzhen Institute of Advanced Technology Chinese Academy of Sciences.