Automatic Illumination Control Algorithm for Capturing the Finger Vein Image

In the finger vein recognition, the illumination has a significant effect on the quality of the finger vein image. This paper proposes a peak value-based method (PVM) for adjusting the intensity of near-infrared light source automatically. To obtain high-quality images, a temporary finger vein image is obtained firstly. We then extract the object region and adjust rotation angle using the linear fitting. Through these operations, we obtain the center line of the finger, whose pixel values are used to determine whether the light intensity of the source is appropriate and then the control unit adjusts the intensity according to the pixel values. Thus, a finger vein image is obtained. We design a finger vein acquisition system that efficiently adjusts the illumination using the proposed PVM. In this paper, we obtain both the angle-calibrated finger vein image and the phalangeal joint location. Experimental results demonstrate that the clear and stable finger vein images can be obtained using proposed automatic illumination control algorithm.