A topological approach to the matching of single fingerprints
Malcolm K. Sparrow, Penelope J Sparrow · 1985
The motivation for seeking topological descriptions of single fingerprints is provided by the elasticity of the human skin; successive rolled im- pressions from the same finger will invariably have suffered a degree of relative distortion (translation, rotation and stretching).Topology based systems should be free from the detrimental effects of plastic distortion.Systems are described for the extraction of simple topological codes from rolled impressions of the pattern types 'loops,' 'whorls' and 'arches.'The generated codes take the form of vectors or simple digital arrays.The nature and frequency of changes that may occur in such codes is investigated and fingerprint comparison algorithms, based on these top- ological codes, are developed.The objective of such algorithms is to draw a score derived from the degree of 'nearness' of the topological codes in such a manner that it intelligently reflects similarity or dissimilarity in the two prints under comparison.Detailed analysis of the performance of such algorithms is given, making extensive use of the results of investigation into the 'match' and 'mismatch' score distributions produced by each one.A final test is described in which the most effective 'topology-based' algorithm was directly tested against one of the best existing 'spatial' algorithms.Topology-based coding, with the inclusion of a crude 'distance measures,' is found to be an extremely accurate and efficient basis for the compari- son of rolled impressions.