Abstract: A method for automatic fingerprint classification is dependent on the number of core points and the ridge flow direction around the core points. The speed of the classification process is improved by pre-processing the fingerprint image to identify the background blocks and the fingerprint blocks, so that the process only deal with the fingerprint blocks. A block directional image is constructed for the fingerprint blocks. The block directional image is then used to determine the core point(s) of the fingerprint. Based on the number of core point and the trend of the ridge direction around each core point, fingerprints can be classified into 8 classes based on a set of predetermined rules.

Abstract: A method to extract automatic high level features of a gray level ridge flow image including the automatic determination of the location of the high level features including the core and delta points of a fingerprint image in the form of a gray level image, comprising the following five steps:(1) determining a ridge flow direction of each gray level pixel of a fingerprint image and assign it with a direction code;(2) finding out a block directional flow and assigning each with appropriate direction code thereof;(3) correcting block flow directions in which a detection of the flow direction is affected image an input image quality in order to be immune from noises infiltrated during the acquiring process;(4) locating the delta points which are based on a corrected block direction flow diagram to locate from zero to a few delta points; and(5) locating the core points which are based on a corrected block direction flow diagram to locate one to two core points.

Abstract: A finger-moistening device for fingerprint recognizing apparatus includes: a container filled with a non-volatile oil or liquid in the container, a powder-metallurgy made roller rotatably mounted and capillarily impregnated in the container to form an oil-impregnated roller, and an upper cover covering the container and having an opening for protruding a peripheral portion of the roller outwardly from the cover and the container for spreading a thin layer of oil or liquid onto the finger of a person to be detected to increase the cohesion between the finger and a prism surface of the fingerprint recognizing apparatus for obtaining a clear fingerprint image for a qualified fingerprint recognition.

Abstract: A fingerprint recognizing apparatus includes: a prism, an electroluminescent device secured or adhered on an incident surface of the prism for emitting a uniform light towards a finger-laying surface of the prism with the light beam reflected at the valleys of the fingerprint, a photosensor selected from a charge-coupled-device (CCD) sensing camera for picking up the image as reflected from the prism for converting the image signal to be a voltage signal, and an image processing and recognizing circuit for processing the voltage signal for fingerprint identification, wherein the energizing of the ELD is synchronized with the image processing and recognizing for a reliable fingerprint recognization.