Determining document fitness using illumination

• US 8,781,176 B2
• Filed: 10/04/2013
• Issued: 07/15/2014
• Est. Priority Date: 11/25/2008
• Status: Expired due to Fees

• Current Assignee: De la Rue North America Inc (De La Rue PLC)
• Original Assignee: De la Rue North America Inc (De La Rue PLC)
• Inventors: Blair, Ronald Bruce
• Primary Examiner(s): AZARIAN, SEYED H
• Application Number:
  US14/045,959
• Publication Number:
  US 20140037148A1
• Time in Patent Office: 284 Days
• Field of Search: 382/100, 382/106, 382/108, 382112-115, 382135-141, 382/162, 382/168, 382/173, 382/181, 382/191, 382/103, 382/194, 382/199, 382/209, 382/219, 382/232, 382/254, 382/274, 382/276, 382290-292, 382/305, 382/312, 382/286, 358/474, 235/379, 340/5.8
• US Class Current: 382/112
• CPC Class Codes: G06F 18/251 of input or preprocessed data
• CPC Class Codes: G06V 10/141 Control of illumination
• CPC Class Codes: G06V 10/143 Sensing or illuminating at different wavelengths
• CPC Class Codes: G06V 10/145 Illumination specially adapted for pattern recognition, e.g. using gratings
• CPC Class Codes: G06V 10/803 of input or preprocessed data
• CPC Class Codes: G06V 30/416 Extracting the logical structure, e.g. chapters, sections or page numbers; Identifying elements of the document, e.g. authors
• CPC Class Codes: G07D 7/1205 Testing spectral properties
• CPC Class Codes: G07D 7/121 Apparatus characterised by sensor details
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means

Abstract

According to an illustrative embodiment, a method for detecting a document includes capturing a first plurality of images of a document at a first wavelength of electromagnetic radiation, capturing a second plurality of images of the document at a second wavelength of electromagnetic radiation, and assembling the first and second pluralities of images to form one or more images of the document.

Claims

1. A method for detecting a document, the method comprising:

moving the document in a first direction;

capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation;

capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation;

assembling the first and second pluralities of line scans to form one or more images of at least portion of the document; and

wherein at least a portion of the first plurality of line scans are captured substantially perpendicular to the direction of travel of the document.

2. The method of claim 1, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of line scans at a first wavelength of reflective electromagnetic radiation within a visible spectrum;

and wherein the step of capturing a second plurality of line scans comprises capturing a second plurality of lines at a second wavelength of reflective electromagnetic radiation within a visible spectrum.

3. The method of claim 1, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of lines at a first wavelength of reflective electromagnetic radiation within a visible spectrum.

4. The method of claim 3, wherein the step of capturing a second plurality of line scans comprises capturing a second plurality of lines at a second wavelength of reflective electromagnetic radiation.

5. The method of claim 1, wherein the first and second pluralities of line scans are assembled to form two or more images of at least a portion of the document.

6. The method of claim 1, further comprising:

moving the document once past at least one electromagnetic radiation source and at least one imaging device.

7. The method of claim 1, wherein assembling the first and second pluralities of line scans to form one or more images of at least a portion of the document comprises:

assembling the first plurality of line scans to form a first image of at least a portion of the document from the first wavelength of electromagnetic radiation; and

assembling the second plurality of line scans to form a second image of at least a portion of the document from the second wavelength of electromagnetic radiation.

8. The method of claim 1, further comprising:

capturing three or more pluralities of line scans of at least a portion of the document at three or more respective wavelengths of electromagnetic radiation; and

assembling the three or more pluralities of line scans to form three or more images of at least a portion of the document.

9. The method of claim 1, wherein each of the one or more images of at least a portion of the document are monochromatic.

10. The method of claim 1, further comprising:

determining whether the document is authentic using the one or more images of at least a portion of the document.

11. The method of claim 1, further comprising:

determining a fitness of the document using the one or more images of at least a portion of the document.

12. The method of claim 11, wherein determining the fitness of the document using the one or more images comprises:

creating a transformed image of the at least a portion of the document using the one or more images; and

determining the fitness of the document using the transformed image.

13. The method according to claim 11, wherein determining the fitness of the document comprises determining a presence of at least one of soiling, ink wear, staining, graffiti, tearing, or security feature wear on at least a portion of the document.

14. The method of claim 1, wherein the document has a first side and a second side;

and

wherein the capturing of the first plurality of line scans, the capturing of the second line scans, and the assembling of the first and second pluralities of line scans to form the one or more images of the at least a portion of the document are performed on each of the first side and the second side of the document.

15. The method of claim 1, further comprising:

illuminating the at least a portion of the document with the first wavelength of electromagnetic radiation, the first plurality of line scans captured while the at least a portion of the document is at least partially illuminated with the first wavelength of electromagnetic radiation; and

illuminating the at least a portion of the document with the second wavelength of electromagnetic radiation, the second plurality of line scans captured while the at least a portion of the document is at least partially illuminated with the second wavelength of electromagnetic radiation.

16. The method of claim 1, further comprising:

sequentially illuminating the at least a portion of the document using two or more wavelengths of electromagnetic radiation according to a predetermined sequence.

17. The method of claim 1, wherein the capturing of the first plurality of line scans and the capturing of the second plurality of line scans occurs while the document is illuminated with at least one of the first or second wavelengths of electromagnetic radiation.

18. The method of claim 1, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation and at a first azimuth relative to the document, and wherein step of capturing a second plurality of line scans comprises capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation and at the first azimuth relative to the document.

19. The method of claim 1, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation and at a first azimuth relative to the document, and wherein the step of capturing a second plurality of line scans comprises capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation and at a second azimuth relative to the document.

20. A method for detecting a document, the method comprising:

moving the document in a first direction;

capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation;

capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation;

assembling the first and second pluralities of line scans to form one or more images of at least portion of the document;

capturing three or more pluralities of line scans of at least a portion of the document at three or more respective wavelengths of electromagnetic radiation; and

assembling the three or more pluralities of line scans to form three or more images of at least a portion of the document.

21. The method of claim 20, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation and at a first azimuth relative to the document, and wherein step of capturing a second plurality of line scans comprises capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation and at the first azimuth relative to the document.

22. The method of claim 20, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation and at a first azimuth relative to the document, and wherein the step of capturing a second plurality of line scans comprises capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation and at a second azimuth relative to the document.

23. The method of claim 20, wherein the step of capturing a first plurality of line scans comprises capturing a first plurality of line scans of at least a portion of the document at a first wavelength of electromagnetic radiation and at a first azimuth relative to the document, wherein step of capturing a second plurality of line scans comprises capturing a second plurality of line scans of at least a portion of the document at a second wavelength of electromagnetic radiation and at the second azimuth relative to the document, and wherein the step of capturing three or more pluralities of line scans of at least a portion of the document at three or more respective wavelengths of electromagnetic radiation comprises capturing a third plurality of line scans of at least a portion of the document at a third wavelength of electromagnetic radiation and at a third azimuth relative to the document.