US 7,599,531 B2 · Method and arrangement for optical recording of biometric finger data

Abstract

A method for acquiring biometric data of a finger a surface to be imaged includes touchlessly and simultaneously imaging a finger surface to be imaged along at least three different directions into digital images, wherein each point of the surface to be imaged is imaged along at least two of the directions and wherein the surface to be imaged extends from a first nail edge across a finger-ball to a second nail edge. Subsequently, a geometric basic model for at least a part of the finger is determined using at least one of the digital images. Pre-warped images are calculated by geometrically pre-warping the digital images using the geometric basic model. Additionally, a three-dimensional model of the surface to be imaged is reconstructed using a stereoscopic analysis of the pre-warped images and at least one finger characteristic is determined using the three-dimensional model.

Claims23

Dependent claims

A method for acquiring biometric data of a finger having a nail and a finger-ball, the method using a control unit and comprising:

touchlessly and simultaneously imaging a surface to be imaged along at least three different directions so as to create at least three digital images, the surface to be imaged extending from a first nail edge, across the finger-ball, to a second nail edge, wherein each point of the surface to be imaged is imaged along at least two of the at least three different directions;
determining a geometric basic model for at least a part of the finger using at least one of at least three digital images;
geometrically pre-warping the at least three digital images using the geometric basic model so as to calculate at least three pre-warped images;
reconstructing a three-dimensional model of the surface to be imaged using a stereoscopic analysis of the at least three pre-warped images;
and
determining at least one finger characteristic using the three-dimensional model.

3 more elements

An arrangement for acquiring biometric data of a finger, comprising:

a system axis;
a surface to be imaged of the finger disposed at the system axis, the surface to be imaged extending from a first nail edge across a finger-ball to a second nail edge;
at least three image receivers disposed on a virtual arc around a system axis and each aiming toward the system axis in a corresponding direction, the at least three image receivers configured to image the surface to be imaged along the corresponding directions touchlessly into digital images, and configured to image each point of the surface to be imaged along at least two of the corresponding directions;
and
a control unit usable to:
a) simultaneously trigger the image receivers for taking the digital images;
b) determine a geometric basic model for at least a part of the finger using at least one of the digital images;
c) calculate pre-warped images by geometrically pre-warping the digital images using the geometric basic model;
d) reconstruct a three-dimensional model of the surface to be imaged using a stereoscopic analysis of the pre-warped images;
and
e) determine at least one finger characteristic using the three-dimensional model.

8 more elements

Dependencies are inferred from the claim text.

Method and arrangement for optical recording of biometric finger data

Life of this patent

Method and arrangement for optical recording of biometric finger data

Life of this patent

Abstract

Claims23