Apparatus and method for contactless high resolution handprint capture

摘要

A system and method for contactless handprint capture is disclosed that includes an image capture device to capture whole handprint images of a subject hand at each of a plurality of different focal distances, with the image capture device including an imaging camera and an electro-optics arrangement having a plurality of light modulating elements and polarization sensitive optical elements having differing optical path lengths based on polarization states. A control system is coupled to the image capture device to cause the device to capture the handprint images at each of the different focal distances, with each handprint image having a depth-of-focus that overlaps with a depth-of-focus of handprint images at adjacent focal distances such that redundant handprint image data is captured. The control system registers each handprint image with positional data and creates a composite handprint image from the handprint images captured at the different focal distances.

主权项

1. A contactless biometric data collection device comprising:
an image capture device configured to capture whole handprint images of a subject hand in any of a range of positions and at each of a plurality of different focal distances, wherein the image capture device comprises:
an imaging camera configured to capture each of the whole handprint images as a single-shot image, with each of the handprint images being captured at a first image resolution level; andan electro-optics arrangement positioned between the hand and the imaging camera, the electro-optics arrangement including a plurality of light modulating elements and polarization sensitive optical elements having an optical path length that changes with different polarization states, so as to provide for capture of the handprint images at each of the plurality of different focal distances; and a control system coupled to the image capture device, the control system being configured to:
cause the image capture device to capture the single-shot handprint images at each of the plurality of different focal distances, each single-shot handprint image having a depth-of-focus that overlaps with a depth-of-focus of handprint images at adjacent focal distances such that redundant handprint image data is captured;register each single-shot handprint image with positional data regarding a position of the hand relative to the imaging camera so as to create pixel correspondence between the handprint images and between portions of the hand; andcreate a composite handprint image from the registered handprint images captured at each of the plurality of different focal distances.