Fingerprint Best Practices Guidelines PDF

Fingerprint Best Practices Guidelines Version 2.0 www.umpi.it  Guidelines - Ver. 2.0 Fingerprint Best Practices Versions Version 2.0 July 2023 Version 1.2 October 2014 Version 1.1 Octo...

Fingerprint Best Practices Guidelines Version 2.0 www.umpi.it  Guidelines - Ver. 2.0 Fingerprint Best Practices Versions Version 2.0 July 2023 Version 1.2 October 2014 Version 1.1 October 2010 Version 1.0 May 2006 2  Guidelines - Ver. 2.0 Fingerprint Best Practices 1. Fingerprint acquisition The aim of fingerprint acquisition is to have a good fingerprint that can be recognized. To achieve this result some effort should be put in place to acquire a good first sample, and following this short manual will make the acquisition process clear and effortless. All the manual can be summarized in 5 rules: 1. Good finger 2. Good positioning 3. Skin treatment 4. User training 5. Correct cleaning 1.1. Good finger In principle, each of the ten fingers can be used for fingerprint verification/recognition; in practice, better results are achieved by using forefingers, and middle fingers and thumbs. The 4th and the 5th fingers are usually too small and the details of their patterns not clear enough. 1.2. Good positioning The finger center should be placed as close as possible to the center of the sensor in order to maximize the usable fingerprint area. Place the finger at the center 3  Guidelines - Ver. 2.0 Fingerprint Best Practices The whole finger area should adhere to the sensor surface: the finger must be kept horizontal (with no tilt). Place the fingerprint, not the tip To avoid to produce deformed images (stretched or compressed in one direction), once the finger skin touches the sensor surface, no further movements should be made; in case of incorrect positioning the finger must be raised up and placed again. Do not move sideways 4  Guidelines - Ver. 2.0 Fingerprint Best Practices 1.3. Skin treatment Dry fingers tend to produce low contrasted images, while wet fingers tend to produce black images. If a finger is too wet it should be dried up with a cloth. If a finger is too dry, the skin perspiration could be revitalized, rubbing a finger into the palm or against another finger. This happens more during cold seasons. Please note that using a disinfectant gel will wet the finger for the first seconds, but will dry up the skin after evaporation. 1.4. User training A good practice is to initially submit the users to a short learning stage, before the enrolment phase, where they interact with the sensor and receive visual feedback from the screen showing their fingerprint images. If training is not possible, clear instruction should be available as pictograms near enrolment station. 1.5. Correct cleaning The sensor surface must be kept clear from grease and dirt which can be left by fingers after use. To this purpose a soft moist cloth can be used. Do not use solvents. Do not spray liquids over the acquisition surface. 5  Guidelines - Ver. 2.0 Fingerprint Best Practices 2. Fingerprint quality score FxISO SDK allows to compute a quality score for each acquired fingerprint. The score is a value between 0 (poor quality) and 100 (good quality). It is recommended to discard fingerprints that have a low score (