Skin Detection System Using Infrared Optoelectronic Technology and Its Application in Facial Recognition

Abstract

Facial recognition technology has made significant progress. However, variable lighting conditions can affect its performance. Considering the need to scan facial skin for recognition purposes, this study proposes a miniature optoelectronic acquisition system for skin in the near-infrared range. The system utilizes the C11708MA photodetector from Hamamatsu Photonics’ MS series as the probe for spectral data acquisition. Other hardware components are designed accordingly. A three-stage amplification buffer circuit is employed as the front-end acquisition and preprocessing circuit. The AD7671 chip from Analog Devices Inc. is selected as the AD converter, and the communication module utilizes the CY7C68013 chip from Cypress’ EZ-USB FX2 series. The control and transmission module employs the EP2C5T144C8N FPGA chip from ALTERA’s Cyclone II generation. In order to address the power supply requirements of the CY7C68013 USB chip (3.3 V), the FPGA core (1.2 V), and the AD7671 and front-end preprocessing circuit (5 V), AMS1117 voltage regulator chips are designed for stable 5 V–1.2 V and 5 V–3.3 V power supplies. In the experiments, wavelength calibration and spectral preprocessing are performed on the system prior to data processing. Near-infrared reflectance spectra of different skin conditions (melanoma, vitiligo) are compared with normal skin. The results demonstrate the accurate assessment capability of the designed infrared optoelectronic skin detection system. Facial skin data obtained from the system are used to generate facial images, and the recognition performance of different detection systems is compared in an algorithmic environment, thereby demonstrating the promising application prospects of the infrared optoelectronic skin detection system in the field of facial recognition.