Fusion of biometric algorithms in the recognition problem

This note concerns the mathematical aspects of fusion for several biometric algorithms in the recognition or identification problem. It is assumed that a biometric signature is presented to a system which compares it with a database of signatures of known individuals (gallery). On the basis of this comparison, an algorithm produces the similarity scores of this probe to the signatures in the gallery, which are then ranked according to their similarity scores of the probe. The suggested procedures define several versions of aggregated rankings. An example from the Face Recognition Technology (FERET) program with four recognition algorithms is considered.