Patent ID: 7310434
Filing Date: 2007-12-18
Classification: H04N

Abstract:
1. A fingerprint authentication apparatus for processing image signals of a finger read out from a sensor containing a plurality of photoelectric converters arrayed two dimensionally and producing first, second, and third image signals of a plurality of lines of pixels comprising first and second sets of lines of pixels that are different from each other, the apparatus comprising: a low-pass filter receiving the first set of lines of the first image signal of the finger and being configured: the low-pass filter being configured to extract from the first set of lines of the first image signal of the finger obtained by the sensor, the shading-noise signal component having a frequency range lower than a predetermined frequency, the predetermined frequency being lower than a frequency capable of expressing fingerprint ridges; a shading data generator configured a removing unit configured to subtract from the third image signal of the finger obtained by the sensor not having passed through the low-pass filter or the shading data generator, the shading-noise signal component of the second set of lines of the second image signal generated by said shading data generator, and to output a difference image signal; and a verification unit configured to match the difference image signal output from said removing unit with a pre-stored image signal.