3D fingerprint scanner promises accuracy and speed at low cost
A 3D fingerprint scanner has been developed that boasts faster speed and accuracy for use in identification, crime investigation, immigration control, security of access and forensic applications.
Automated contact-based 2D fingerprinting identification is commonly used by law-enforcement agencies to identify people.
However, contact-based acquisition of biometric scans by rolling or pressing fingers against a hard surface such as glass, silicon or polymer often results in partial or degraded images due to skin deformations, slippages or smearing.
This produces images that are not fully useful for the identification. Non-contact fingerprint systems, on the other hand, avoid direct contact between the imaging sensor and the elastic surface of the skin, and can thus reduce inaccuracies arising from problems associated with contact-based systems.
Although there are emerging contactless 3D systems, they tend to be very expensive and bulky due to their use of multiple cameras or structured lighting systems.
A research team led by Dr Ajay Kumar from Hong Kong Polytechnic University (PolyU) has developed a device that overcomes the limitations of contact-based 2D biometric scans and maximises the advantages from the contactless 3D systems.
The minutiae features from the fingerprint ridges – such as ridge ending and bifurcation – are universally considered to be the most reliable of fingerprint details, ensuring that each fingerprint is unique.
About 40-45 minutiae points can be recovered from a fingerprint on average. The more minutiae points are matched, the higher is the confidence and reliability in the matching.
All fingerprinting systems commercially available today still recover the minutiae details in 2D form, i.e. by locating the minutiae position and minutiae orientation in 2D spaces.
The 3D fingerprint scanner is capable of determining minutiae height and minutiae orientation in 3D spaces on top of the representations in 2D spaces read by traditional scanners. The extra data allows for a more unique representation of individual’s fingerprints.
The system uses a single, low-cost digital camera coupled with a few LED light sources controlled by a computer.
This allows fingerprint data to be acquired at high frequency using proprietary 3D fingerprint template generation algorithms to recover 3D minutiae features.
The developers say the compact size, high accuracy of around 97 per cent, reduced cost of up to $780, the faster processing time of approximately 2 seconds, and reduced amount of equipment needed make for a more system with greater potential than the currently used commercial 3D counterparts.
In January, Japanese researchers found that fingerprints could be copied from selfies taken at a distance of just a few metres with a standard smartphone in which the subject is flashing a V sign.