×

Multi-spectral imaging using longitudinal chromatic aberrations

  • US 9,945,777 B2
  • Filed: 01/14/2016
  • Issued: 04/17/2018
  • Est. Priority Date: 01/14/2016
  • Status: Active Grant
First Claim
Patent Images

1. An imaging device for detecting counterfeit bills, the image device comprising:

  • an objective lens having symmetry around an optical axis, the objective lens configured to disperse images of a bill in longitudinal chromatic aberrations along the optical axis;

    a sensor configured to obtain multiple images of the bill, each image corresponding to a specific wavelength within a predetermined spectrum from ultraviolet to near infrared;

    a processor configured to analyze the multiple images to detect features of the bill, wherein the processor is configured to process the multiple images to obtain a three-dimensional image stack comprising a plurality of images respectively corresponding to one of a plurality of different wavelengths in the spectrum, wherein the processor is configured to;

    compare one or more regions of each of one or more of the plurality of images in the three-dimensional image stack, to one or more regions of a corresponding image of an original bill selected from a three-dimensional image stack comprising a plurality of images of the original bill respectively corresponding to the one of the plurality of different wavelengths in the spectrum; and

    determine whether the bill is counterfeit based at least in part on the comparison.

View all claims
  • 1 Assignment
Timeline View
Assignment View
    ×
    ×