METHOD OF , AND APPARATUS FOR, EDGE ENHANCEMENT OF FINGERPRINT MINUTIA

A method for enhancement of edge detail in fingerprint minutia first illuminates the finger with light passing through a polarizer in a first direction with respect to the polarization plane, for at least a portion of one rotation of the light source/polarizer about an optical axis generally perpendicular to the finger. The light reflected from the finger is converted to video data during at least a selected part of the rotation and the first set of video data is stored in a first storage means register. The illuminating, converting and storing steps are then repeated with light from a second direction, substantially orthogonal the first direction, illuminating the finger, and with a second set of video data, (for at least the same part of another rotation) being stored in a second register. Arithmetically processing of the video data in the first and second storage registers is used to obtain a video output signal in which image edge detail data has been enhanced with respect to edge detail data obtainable from either the first and second sets of video data.