Abstract: A method for generating data characteristic of a rolled fingerprint image in real time. A finger is continuously rolled across a finger receiving surface of an optical device. The finger receiving surface is imaged to generate digital data representative of fingerprint images propagated therefrom. A first array of data characteristic of a fingerprint image of a first finger slice is stored, and merged into a composite array. After the first array is merged into the composite array, a second array of data characteristic of a second finger slice which is adjacent to and overlaps the first finger slice is stored. The second array is then merged into the composite array by storing data in the composite array as a function of a comparison and an average of data in the composite array and second array which are characteristic of overlapping portions of the finger slices.

Abstract: Methods for operating a programmable digital computer to enhance images of fingerprints represented by an array of pixel values. Methods for noise averaging, illumination equalizing, directional filtering, unhairing, curvature correcting, and scale correcting a fingerprint image are disclosed.

Abstract: An optical fingerprinting system includes an optics/processor unit, a video monitor, a data terminal, and a printer. The optics/processor unit includes a slap print prism for providing slap fingerprint images, and a plurality of individual finger prisms having differently sized finger-receiving grooves for providing individual fingerprint images. Slap/finger image selection optics selectively propagate fingerprint images from one of the individual finger prisms or slap print prism to a video camera. A video monitor is coupled to the camera, and provides a real-time display of the fingerprints being imaged. When a desired fingerprint image is observed on the monitor, an appropriate key of a key pad on the optics/processor unit is actuated and digital data characteristic of this image stored in memory. Following this procedure, data characteristic of all ten individual fingerprints and slap prints of both hands is stored.