This report describes a system for verification of fingerprints against a previous created template. It describes how and why a fingerprint image must be processed before it can be used to either identify or verify a person. The method is based on special features of a fingerprint, called minutiae points. The whole process from image to matching is described, every step in the process with image enhancement, binarization, thinning and how to find the minutiae points. Also what false minutiae points are, how they arise, why they deteriorate the result, and how to handle them, is discussed.