FINGERPRINT SENSING SYSTEM CONFIGURED TO DETERMINE IF A FINGER CONTACTS A FINGERPRINT SENSOR

摘要

The invention relates to a method performed by a fingerprint sensing system (101) of determining if a finger contacts a fingerprint sensor (102) of the system, and a fingerprint sensing system (101) performing method. In a first aspect of the invention, a method performed by a fingerprint sensing system (101) is provided for determining if a finger contacts a fingerprint sensor (102) of the fingerprint sensing system (101). The method comprises capturing (S101) an image of an object contacting the fingerprint sensor (102), determining (S102) an intensity for a plurality of pixels of the captured image, estimating (S103) local curvatures of pixel intensity variation in the captured image, and determining (S104) from the estimated local curvatures if local pixel intensity variation is dominated by a single direction, in which case the object on the sensor (102) is considered to constitute a finger.