A Fingerprint Capture System and the Corresponding Image Quality Evaluation Algorithm Based on FPS200

A design of the fingerprint capture system based on chip FPS200 is introduced. The capture system uses the MCU interface with DSP. In this paper, a new method based on the intrinsic directional features of fingerprint is proposed to evaluate the quality of images acquired by FPS200 sensor. Using directional map, the available area of image and clearness is checked to calculate the overall image quality score that can be used to quantitatively determine the quality of the fingerprint image. If the quality of image is unsatisfied, prompt is presented: whether the finger is wet or dry, then DSP adjusts the parameters of FPS200 sensor automatically until image of good quality has been acquired. Experimental results show that the performance of AFIS has indeed improved.