Mosaicing Touchless Fingerprint Images

Abstract

Touchless fingerprint sensing technologies have been explored to solve problems in touch-based sensing techniques because they do not require any contact between a sensor and a finger. While they can solve problems caused by the contact of a finger, other difficulties emerge such as a view difference problem and a limited usable area due to perspective distortion. In order to overcome these difficulties, we propose a new touchless fingerprint sensing device capturing three different views at one time and a method for mosaicing these view-different images. The device is composed of a single camera and two planar mirrors reflecting side views of a finger, and it is an alternative to expensive multiple-camera-based systems. The mosaic method can composite the multiple view images by using the thin plate spline model to expand the usable area of a fingerprint image. In particular, to reduce the affect of perspective distortion, we select the regions in each view by minimizing the ridge interval variations in a final mosaiced image. Results are promising as our experiments show that mosaiced images offer 29% more true minutiae and 28% larger good quality area than one-view, unmosaiced images. Also, when the side-view images are matched to the mosaiced images, it gives more matched minutiae than matching with one-view frontal images. We expect that the proposed method can reduce the view difference problem and increase the usable area of a touchless fingerprint image. Furthermore, the proposed method can be applied to other biometric applications requiring a large template for recognition.

Existing System

The existing system is the touch based fingerprint image. The multispectral fingerprint imaging (MSI) technique is another existing method which is also a touch based method. Various kinds of fingerprint image acquisition sensors have been utilized in a wide range of forensic and commercial applications, e.g., criminal investigation, e-commerce, access control, issuing national ID cards and e-passports, etc. Because these types of sensing systems are touch-based, users must press or roll their fingers onto a platen surface to capture fingerprint image. this capturing scheme often introduces degraded images due to skin deformation (due to skin elasticity and nonuniform pressure), skin condition changes (due to environmental changes and skin characteristics), and latent fingerprints on the sensor surface. the rise in forgeries in touch-based sensor systems has become a serious problem, while some individuals avoid public usage of touch-based sensors due to concerns regarding hygiene.

Proposed System

To overcome problems in the existing system, a touchless fingerprint sensing technology has been proposed that does not require any contact between a sensor and a finger. Thus, the finger’s minutiae and ridge information cannot be changed or distorted as it will be free of skin deformation. Also, it can capture fingerprint images consistently because it is not affected by different skin conditions or latent fingerprints. The method used in our proposed scheme is the Mosaic Method for synthesizing an expanded fingerprint image from frontal- and side-view images. Hence this paper describes a novel touchless fingerprint sensing device which covers three views of a fingerprint and a method for mosaicing these images to expand the effective area of a fingerprint.

Architecture