1. A method of assembling an image of a fingerprint from a series of partial fingerprint images and finger position data obtained by a partial fingerprint imager comprising: obtaining finger tip position data as the finger swipes the partial fingerprint imager; determining the motion parameters versus time of the finger tip, and compensating for inadequate finger position data by extrapolating the motion parameters to determine probable fingertip position versus time as the tip of the fingertip swipes over the partial fingerprint imager.