In the previous section, we discussed the use of the first biometric, which is the face of the person trying to log in to the system. However, since we mentioned that using a single biometric is risky, it is better to add secondary biometric checks to the system, like a fingerprint. There are several off-the-shelf fingerprint scanners that are quite cheap and return you a scanned image. However, you will still have to write your own registration software for these scanners, and this can be done with OpenCV. Examples of such fingerprint images can be found below:

Examples of single individual thumbprints from different scanners

This dataset can be downloaded from the FVC2002 competition website released by the University of Bologna. The website (http://bias.csr.unibo.it/fvc2002/databases.asp) contains four databases of fingerprints available for public download in the following format: