We propose a new gradient-based method for the extraction of the orientation field associated to a
fingerprint, and a regularisation procedure to improve the orientation field computed from noisy
fingerprint images. The regularisation algorithm is based on three new integral operators, introduced and
discussed in this paper. A pre-processing technique is also proposed to achieve better performances of the
algorithm. The results of a numerical experiment are reported to give an evidence of the efficiency of the
proposed algorithm
