System and method for scene image acquisition and spectral estimation using a wide-band multi-channel image capture

• US 7,554,586 B1
• Filed: 10/20/2000
• Issued: 06/30/2009
• Est. Priority Date: 10/20/1999
• Status: Expired due to Fees

• Current Assignee: Rochester Institute of Technology
• Original Assignee: Rochester Institute of Technology
• Inventors: Berns, Roy Stephen, Imai, Francisco Hideki
• Primary Examiner(s): Henn; Timothy J
• Application Number:
  US09/692,923
• Time in Patent Office: 3,175 Days
• Field of Search: 348/188, 348/266, 348268-270, 348/370, 348/371, 348/360, 348/361, 348/342
• US Class Current: 348/269
• CPC Class Codes: G01J 2003/1282 Spectrum tailoring
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: H04N 1/2112 using still video cameras
• CPC Class Codes: H04N 1/212 Motion video recording combined with still video recording television signal recording H04N5/76
• CPC Class Codes: H04N 1/215 Recording a sequence of still pictures, e.g. burst mode
• CPC Class Codes: H04N 1/54 Conversion of colour picture signals to a plurality of signals some of which represent particular mixed colours, e.g. for textile printing
• CPC Class Codes: H04N 2101/00 Still video cameras
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/84 for processing colour signals

Abstract

A system and method for multi-spectral image capture of a first scene includes acquiring a first series of images of the first scene with one or more image acquisition systems and filtering each of the first series of images of the scene with a different non-interference filter, illuminating each image of the first series of images with a different illuminant, or acquiring each of the images of the first series of images with a different image acquisition system. Each of the image acquisition systems has at least one color channel, each of the non-interference filters has a different spectral transmittance, and each of the illuminants has a different spectral power distribution.

Claims

1. A method for multi-spectral image capture of a first scene, the method comprising:

acquiring a first series of images of the first scene with one or more image acquisition systems, each of the image acquisition systems having an imaging sensor which has a set of color filters thereon and has two or more color channels, each of the channels having a different spectral sensitivity;

filtering each of the first series of images of the scene with a different filter from a set of non-interference, color filters, each of the non-interference filters in the set of the non-interference filters having a different spectral transmittance and is positioned between the scene and the one or more image acquisition systems;

acquiring a second series of images of a second scene with the one or more image acquisition systems; and

filtering each of the second series of images of the second scene with a different filter from the set of filters;

generating a characteristic mapping from two or more color channel signals from the second series of filtered images; and

generating a multi-spectral scene description from two or more of the acquired first series of filtered images.

2. The method as set forth in claim 1 further comprising generating a spectral reflectance of the first scene from the multi-spectral scene description and the characteristic mapping.

3. The method as set forth in claim 2 further comprising using the generated spectral reflectance to reproduce the first scene.

4. The method as set forth in claim 2 further comprising storing the generated spectral reflectance for the first scene.

5. The method as set forth in claim 1 further comprising illuminating each image of the first series of images with one or more illuminants.

6. The method as set forth in claim 1 further comprising illuminating each image of the first series of images with an illuminant from a set of two or more illuminants as each of the first series of images is being acquired, each of the illuminants having a different spectral power distribution.

7. The method as set forth in claim 1 wherein the set of non-interference filters comprise at least one of an absorbance filter, a writable filter, and a liquid crystal tunable filter.

8. The method as set forth in claim 7 wherein the non-interference filters are the absorption filters.

9. An apparatus for multi-spectral image capture of a first scene, the apparatus comprising:

one or more image acquisition systems each having an imaging sensor which has a set of color filters thereon and has two or more color channels, each of the channels having a different spectral sensitivity, each of the image acquisition devices acquiring a first series of images of the first scene;

a set of non-interference, color filters, each of the non-interference, filters in the set of the non-interference filters has a different spectral transmittance, is positioned between the scene and the image acquisition system, and filters a different image in the first series of images; and

a spectral image processing system which generates a multi-spectral scene description from two or more of the acquired first series of filtered images, the image acquisition systems acquires a second series of images of a second scene, the set of filters filter each of the second series of images of the second scene with a different filter, the spectral image processing system generates a characteristic mapping from two or more color channel signals from the second series of filtered images.

10. The apparatus as set forth in claim 9 wherein the spectral image processing system generates a spectral reflectance of the first scene from the multi-spectral scene description and the characteristic mapping.

11. The apparatus as set forth in claim 10 further comprising a printing device to reproduce the first scene based on the generated spectral reflectance.

12. The apparatus as set forth in claim 10 further comprising a memory device for storing the generated spectral reflectance for the first scene.

13. The apparatus as set forth in claim 9 further comprising one or more illuminants which illuminate each image of the first series of images.

14. The apparatus as set forth in claim 9 further comprising-a set of two or more illuminants, each of the illuminants having a different spectral power distribution and illuminating one of the images of the first series of images.

15. The apparatus as set forth in claim 9 wherein the set of non-interference filters comprise at least one of an absorbance filter, a writable filter, and a liquid crystal tunable filter.

16. The apparatus as set forth in claim 15 wherein the non-interference filters are the absorption filters.

17. A method for multi-spectral image capture of a first scene, the method comprising:

acquiring a first series of images of the first scene with one or more image acquisition systems, each of the image acquisition systems having an imaging sensor which has a set of color filters thereon and has two or more color channels, each of the channels having a different spectral sensitivity;

illuminating each image of the first series of images with a different illuminant from a set of two or more illuminants, each illuminant having a different spectral power distribution;

generating a multi-spectral scene description from the acquired first series of filtered images;

acquiring a second series of images of a second scene with the one or more image acquisition systems;

illuminating each of the second series of images of the second scene differently; and

generating a characteristic mapping from the second series of filtered images.

18. The method as set forth in claim 17 further comprising generating a spectral reflectance of the first scene from the multi-spectral scene description and the characteristic mapping.

19. The method as set forth in claim 18 further comprising using the generated spectral reflectance to reproduce the first scene.

20. The method as set forth in claim 19 further comprising storing the generated spectral reflectance for the first scene.

21. An apparatus for multi-spectral image capture of a first scene, the apparatus comprising:

an image acquisition system having an imaging sensor which has a set of color filters thereon and has two or more color channels, each of the color channels having a different spectral sensitivity;

a set of two or more illuminants, each illuminant having a different spectral power distribution and illuminating one of the images of the first scene; and

a spectral image processing system which generates a multi-spectral scene description from the acquired first series of filtered images;

wherein the image acquisition systems acquire a second series of images of a second scene and the set of color illuminants illuminate each of the second series of images of the second scene with different spectral power distribution;

wherein the spectral image processing system generates a characteristic mapping from the second series of illuminated images.

22. The apparatus as set forth in claim 21 wherein the spectral image processing system generates a spectral reflectance of the first scene from the multi-spectral scene description and the characteristic mapping.

23. The apparatus as set forth in claim 22 further comprising a printing device to reproduce the first scene based on the generated spectral reflectance.

24. The apparatus as set forth in claim 22 further comprising a memory device for storing the generated spectral reflectance for the first scene.