Abstract: The invention relates to the recognition of digital finger prints, more particularly to recognition by an elongate bar of sensors able to detect crests and valleys of finger prints when a finger is passed in a relative manner in front of a sensor in an essentially parallel manner in relation to the direction of elongation of said bar. The inventive method comprises the following operations: successive partially overlapping images are acquired under the control of a processor; displacement of the first image in relation to a second image is examined in order to provide a better correlation between the two images; said displacement component is determined in terms of pixels in a perpendicular direction with respect to the elongate sensor; the displacement component is compared to at least one threshold; according to the result of the comparison, a delay T imposed by the processor before the acquisition of a following image is preserved, or increased or decreased by a time increment dT.

Abstract: The invention relates to the recognition of persons by biometric identification systems. According to the invention, for the recognition of persons, it is proposed to use an optical or other fingerprint image sensor 10 associated with spectral recognition of the skin using fewer light-emitting elements 12 than if the spectral recognition had been used on its own. The fingerprint image sensor and a sensor for spectral transmission information relating to the skin of the finger whose print is recorded by the image sensor are arranged on the same base.

Abstract: A fingerprint-reading system includes a fingerprint sensor having an active surface sensitive to the pressure and a temperature of a finger. The surface area of this sensor is far smaller than the surface area of the fingerprint to be read. The reading is done when the sensor and the finger are in contact and in a relative motion of sliding of the sensor and the finger with respect to each other. The system reconstitutes a complete image of the fingerprint from the partial images given by the sensor during this motion.

Abstract: A fingerprint-reading system comprises a fingerprint sensor having an active surface sensitive to the pressure and temperature of a finger. The surface area of this sensor is far smaller than the surface area of the fingerprint to be read. The reading is done when the sensor and the finger are in contact and in a relative motion of sliding of the sensor and the finger with respect to each other. The system has means to reconstitute a complete image of the fingerprint from the partial images given by the sensor during this motion. Application inter alia to devices for the authentication of individuals.

Abstract: A fingerprint-reading system includes a fingerprint sensor having an active surface sensitive to the pressure and temperature of a finger. The surface area of this sensor is far smaller than the surface area of the fingerprint to be read. The reading is done when the sensor and the finger are in contact and in a relative motion of sliding of the sensor and the finger with respect to each other. The system reconstitutes a complete image of the fingerprint from the partial images given by the sensor during this motion.