Method and arrangement for registering and verifying fingerprint information

A method for verifying fingerprint information, comprising:

• providing a sensing surface A, at least a part of which receives a finger;
• comparing a number of part surfaces A′1 with their respective center points
• in a registered fingerprint with corresponding part surfaces A′2 on said sensing surface A;
• approving a point P2 with its respective part surface A′2 if the point and its immediate surrounding area A″2 corresponds on the basis of certain criteria to a registered center point P1, including its immediate surrounding area A″1 in a corresponding stored part surface A′1;
• selecting for further processing a certain number of points P2 with associated part surfaces A′2 which have been approved;
• displacing information about the part surfaces A′2 for comparison with part surfaces A′1 in a predetermined number of angular positions, said comparison being carried out with part surfaces A′2 in each of said angular positions, so that if said certain number of points P2 of part surfaces A′2 satisfy said criteria in one in the same angular position, said points P2 are selected for further processing;
• said further processing of points P2 with their respective part surfaces A′2 includes analyzing the points and the part surfaces as follows:
• calculating mean values of the coordinates (x,y) for points P2 and their respective part surfaces A′2;
• considering the calculated mean values as a point in each part surface A′2;
• selecting a certain number of the points P2 with their associated part surfaces A′2 for a second further processing, said selected points having the smallest distance to the mean value point in their respective part surface A′2.

An arrangement for registering fingerprint information comprising:

• a central unit;
• a sensor with a sensing surface A, at least a part of which receives a finger;
• a power supply unit;
• means for scanning part surfaces A′1 in said sensing surface A;
• means for analyzing whether a center point P1 its immediate surrounding area A′1, of the scanned part surface A′1 is unique within the part surface A′1;
• means for registering a first number of center points P1 which with their respective immediate surrounding areas A″1 are unique in their respective part surfaces A′1;
• and
• means for registering the part surfaces A′1 whose center points P1 are registered.

An arrangement for verifying fingerprints on the basis of previously registered information comprising:

• a central unit;
• a sensor having a sensing surface A, at least a part of which sensing surface A receives a finger;
• a power supply unit;
• means for comparing a number of part surfaces A′1 with respective center points P1 in a fingerprint whose information is registered with the corresponding part surfaces A′2 on the sensing surface A;
• means for selecting and approving a number of points P2 with corresponding part surfaces A′2 on the sensing surface A, when said points P2 with their immediate surrounding areas A″2, correspond on the basis of certain criteria to a storage center point P1, including its immediate surrounding area A″1 of the storage center point in the corresponding stored part surface A′1;
• means for further processing said approved points;
• means for displacing information about the part surfaces A′2 for comparison with the part surfaces A′1 through a predetermined number of angular positions, said means for comparing carrying out a comparison in each of said angular positions, and said means for selecting and approving a number of points, approving said number of points P2 of part surfaces A′2 if said points satisfy said criteria in one and the same angular positions;
• said means for further processing including:
• means for analyzing a group of said approved points P2 and part surfaces A′2, means for calculating a mean value point for coordinates (x,y) of the points P2 in the part surfaces A′2 in the group, and means for selecting a certain number of said points P2 where their associated parts A′2 for a second further processing, said points P2 which are selected being those points which have the smallest distance to the mean value point in their respective part surface A′2.