Application and analysis on quantitative evaluation of hand vein image quality

Recognition of hand vein is becoming a research focus in biological recognition field, due to its particular advantage of uniqueness and livingness. In this study, images of hand vein were obtained by near-infrared camera with hand illuminated by near-infrared light source. The acquisition of clear vein image is an important premise for recognition. In the paper, we propose a quantitative evaluation method of image quality based on two spatial indicators, i.e. the mean gray and gray variance, and then study the relationship between the quantitative image scores and the drive current of near-infrared light source. It shows the relationship between the drive current and the evaluation score is quadratic parabolic, and the optimal the drive current of the near infrared light source is obtained. This work provides a good theoretical basis for the design of image acquisition system with the automatic regulation of hand vein image quality.