There are two types of methods for capturing fingerprints, namely, inked (off-line) and live scan (ink-less). Inked fingerprints are captured traditionally by a trained professional who spreads a black ink into the individual's finger. Then, the finger is pressed and rolled against a paper card, which is later scanned to produce the digital image. The inked impression method remains popular especially in forensics, where latent fingerprints are captured from crime scenes. Furthermore, this type of method is not feasible for biometric systems where real-time processing is a need.
Livescan fingerprints are acquired by directly sensing the fingertips over an electronic fingerprint device. Since the images are capture directly in digital form, no intermediate digitization process is required. This makes real-time biometric systems feasible. Nowadays, there are several live-scan fingerprint technologies available. The actual trend is to ensure good quality in the captured images using small, fast, and inexpensive scanning devices.