Empirical study on touchless fingerprint recognition using a phone camera

Existing methods for touchless fingerprint recognition using a phone camera have the difficulties to quickly verify and extract fingerprint images with high recognition accuracy. It is because specialized techniques for touchless fingerprint images were not provided for them. To overcome these difficulties, three methods are proposed. First, a finger-shaped guide is displayed on the phone screen to enable the user to position their fingers correctly and to focus the camera on the position to quickly produce a good fingerprint image. Second, the profile line tests at selected points on the guide are proposed to quickly determine whether the user's fingers are properly placed according to the guide shape and to simplify the segmentation of fingerprint image regions. Third, a existing local structure-based matching method is improved for touchless fingerprint images, and a score-level fusion of the three finger matchings is performed to ensure high recognition accuracy. Experiments were performed using our custom-built database, where touchless fingerprint images were collected using a 13-MP mobile camera in various indoor and outdoor environments. Resulting error rates were between 0.50% and 1.04% depending on whether the image was captured indoors or outdoors.