The impact of fingerprint force on image quality and the detection of minutiae

It is well documented that many factors affect fingerprint image quality such as age, ethnicity, moisture, temperature and force, although force has only been subjectively measured in the literature. Fingerprint image quality is of utmost importance due to its linear relationship with matching performance. Therefore, the purpose of this research is to show how fingerprint force impacts image quality and the number of detected minutiae. Two experiments are presented in this paper that evaluated fingerprint force levels and the impacts on image quality, number of minutiae detected, and user comfort to provide the community with a quantitative measure for force as it relates to image quality. Four force levels (3, 9, 15, and 21 newtons) were evaluated in the first experiment with results indicating that there was no incremental benefit in terms of image quality when using more than 9 N when interacting with an optical fingerprint sensor. The second experiment investigated the 3-9 N interval with results indicating that the optimal image quality is arrived between a force level is 5-7 N.