Overview of biometrics:

Bios  means "life" and metron means "measure") Biometrics is the study of methods to uniquely identify or verify human identities based upon one or more unique physical or behavioral traits.

Overview of fingerprint biometrics:

Fingerprint based biometrics are automated methods designed to identity or verify human identities based upon the unique valleys and ridges present in a fingerprint.

Overview of an SDK:

A software development kit (SDK or "devkit") is  a set of development tools that enable software developers to create applications specific to a certain framework or system.

 

Fingerprint SDK Overview

Overview:
A fingerprint SDK is a software toolkit that allows the integration of biometric fingerprint recognition into various applications. They will typically utilize either DLL or ActiveX (COM) to interface with the integrated application. By referencing these DLL or COM objects, developers are able to utilize the fingerprint functionality from within a desired application. Fingerprint SDKs provide a basic framework of functions to talk to a fingerprint scanner, capture an image, extract the unique minutiae data from the image, and compare two sets of extracted minutiae data. All of the more complex features and functionality are built upon this framework.

Functions:
initialize() -- Initializes the fingerprint SDK API (when starting)
cleanup() -- Release resources initialized by API (when finished)
openDevice() -- Open a fingerprint scanner device
closeDevice() -- Close fingerprint scanner device
captureImage() -- Captures a fingerprint image from device
getMinutiae() -- Extracts minutiae points from captured fingerprint
matchMinutiae() -- Compares two minutiae records (1-to-1)

Common Developer Issues with Fingerprint SDKs:
Good fingerprint scan VS a bad fingerprint scan
How to store the extracted minutiae
How to load the information back from the stored location
How to encrypt/decrypt the stored data
How to create a transmit comparison requests across a network to facilitate a client/server topology
How to associate more than one fingerprint with a given person
How to convert a 1-to-1 comparison functionality and build it into a 1-to-N solution
Reliability of the comparisons against a large population size