fingerprint reader software using C#

Question

I am planning to verify the user input for my application using the biometric input. I did some research on net and came up with following options of biometric input:

1. Fingerprint
2. Facial Recognition
3. Retinal Scan
4. Iris Scan
5. Voice Recognition
6. Signature Verification

Out of which I felt the fingerprint as most suitable options. But the problem with this is the API of the fingerprint device will vary with its hardware. So most probably I think I will need to code against the multiple devices API, which I don't find friendly.

I intend to do the programming stuffs in C#. Is there any way out of this. As I am new to this I'm clueless. What is the way to attack this problem and how vast is the project scope and what should be my approach for this project.

Answer 1

A colleague of mine was tasked with building a biometric based staff clock-in system for the company we both worked for. We, IT, choose Fingerprints as the biometric source. He researched and used this library from Bayometric - Griaule Fingerprint SDK along with some cheap MS print readers. From what he showed me and talked about at the time, does lead me to believe that this .net library had a nice API and was easy to work with.

The biometric system is still being used today, some 5 years later.

Answer 2

The problem is not unique to fingerprint readers, it will apply to all other options in your list and many other peripherals. In fact a standard API is the exception.

So you will have to look for somebody selling a library for this or writing your own (COM and/or Interop). And rolling your own will usually not be small or simple project.

Your program will have a list of supported devices, excluding the rest.

Answer 3

I work in the biometric field, and I use C# for a lot of the fingerprint stuff I do. My company had to develop a fingerprint device abstraction library for this very reason. Consider that all fingerprint scanners only REALLY need one call: getImage. Knowing this, my company wrote a library which initializes and sets up each device, creates a generic wrapper, assigns a unique ID, and throws it into a big list that you can enumerate over.

Then from the C# side all you have to do is "pick" a device (all you have to go on is a unique ID and maybe a manufacturer) and then use it. The image data that comes back has to be decided on in advance so that you know what you're going to get every time

The main problem with this approach is that a lot of devices these days have various gimmicks (e.g. programmable flashing lights), and by abstracting the devices away you lost the ability to access these special abilities. Furthermore, some devices actually return multiple channels of data (various spectrums of light for example) and you have to throw away all but one channel so that the application can remain device agnostic, which is a hard decision.

Finally keep this in mind: if you do minutiae extraction, the device you use unfortunately WILL impact which minutiae are detected. Some devices are "tuned" for certain algorithms, and so enrolling with device A and matching with device B may not work at all despite having picture-perfect fingerprints.