Infrared and near-infrared camera hyperframing

• US 7,634,157 B1
• Filed: 03/23/2006
• Issued: 12/15/2009
• Est. Priority Date: 03/23/2006
• Status: Active Grant

• Current Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Original Assignee: FLIR Systems, Inc. (Teledyne Technologies Incorporated)
• Inventors: D'Souza, Shariff, Richards, Austin A.
• Primary Examiner(s): SHERALI, ISHRAT I
• Application Number:
  US11/388,947
• Time in Patent Office: 1,363 Days
• Field of Search: 382/305, 382/284, 382/167, 382/209, 348/221.1, 348/218.1, 396322-353, 396/18, 396/265, 359629-634, 359/353, 359/485, 359493-501, 250/333, 250/343, 250/347, 356/3.01, 356/4.01, 356/300, 35613901-1391, 436/164, 436171-172, 436/159, 436/147
• US Class Current: 382/305
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0213 using attenuators
• CPC Class Codes: G01J 3/2803 using photoelectric array detector
• CPC Class Codes: G01J 3/32 Investigating bands of a spectrum in sequence by a single detector
• CPC Class Codes: G01N 21/314 with comparison of measurements at specific and non-specific wavelengths dual wavelength spectrometry G01J3/427
• CPC Class Codes: G01N 21/35 using infrared light G01N21/39 takes precedence
• CPC Class Codes: G01N 21/359 using near infrared light
• CPC Class Codes: H04N 25/00 Circuitry of solid-state image sensors [SSIS]; Control thereof
• CPC Class Codes: H04N 25/589 with different integration times, e.g. short and long exposures
• CPC Class Codes: H04N 5/33 Transforming infrared radiation cameras or camera modules for generating image signals from infrared radiation H04N23/20; circuitry of SSIS for transforming infrared radiation into image signals H04N25/20

Abstract

Systems and techniques for imaging spectroscopy using improved data acquisition for infrared and near-infrared imaging. A first filter corresponding to a first wavelength may be positioned in the optical path of an infrared camera, and subframe data may be acquired for different exposures. A second filter corresponding to a second different wavelength may be positioned in the optical path of the infrared camera, and subframe data acquired for different exposures. Image data for the first wavelength and the second wavelength may then be compared to reference spectroscopic data.

Claims

1. An article comprising a computer-readable storage medium embodying information indicative of instructions that when performed by one or more computers result in operations comprising:

positioning a first filter in the optical path of an infrared camera, the first filter configured to pass a narrow wavelength band including a first wavelength;

acquiring first subframe image data associated with the first wavelength at a detector using a first exposure;

acquiring second subframe image data associated with the first wavelength at the detector using a second exposure;

generating first wavelength image data based on at least some of the first subframe image data and the second subframe image data;

positioning a second filter in the optical path of the infrared camera, the second filter configured to pass a narrow wavelength band including a second different wavelength;

acquiring image data associated with the second wavelength at the detector;

generating second wavelength image data based on the image data associated with the second wavelength; and

comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data.

2. The article of claim 1, further comprising determining the presence or absence of a particular material corresponding to the reference spectroscopic data.

3. The article of claim 1, wherein the first wavelength image data comprises image data corresponding to a plurality of pixels of the image, and wherein comparing the first wavelength image data to reference spectroscopic data comprises comparing first wavelength data for each of the plurality of pixels to the reference spectroscopic data.

4. The article of claim 1, wherein acquiring the first subframe image data associated with the first wavelength at the detector using the first exposure comprises acquiring the first subframe image data at a first integration time, and wherein acquiring the second subframe image data associated with the first wavelength at the detector using the second exposure comprises acquiring the first subframe image data at a second different integration time.

5. The article of claim 1, wherein acquiring the first subframe image data associated with the first wavelength at the detector using the first exposure comprises acquiring the first subframe image data using a first filter with a first attenuation, and wherein acquiring the second subframe image data associated with the first wavelength at the detector using the second exposure comprises acquiring the first subframe image data using a second filter with a second different attenuation.

6. The article of claim 1, wherein comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data comprises comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data corresponding to a plurality of different materials.

7. The article of claim 6, wherein the first wavelength image data comprises image data corresponding to a plurality of pixels of the image, and wherein comparing the first wavelength image data to reference spectroscopic data corresponding to the plurality of different materials comprises comparing first wavelength data for each of the plurality of pixels to the reference spectroscopic data for at least one of the different materials.

8. A method comprising:

positioning a first filter in the optical path of an infrared camera, the first filter configured to pass a narrow wavelength band including a first wavelength;

acquiring first subframe image data associated with the first wavelength at a detector using a first exposure;

acquiring second subframe image data associated with the first wavelength at the detector using a second exposure;

generating first wavelength image data based on at least some of the first subframe image data and the second subframe image data;

positioning a second filter in the optical path of the infrared camera, the second filter configured to pass a narrow wavelength band including a second different wavelength;

acquiring image data associated with the second wavelength at the detector;

generating second wavelength image data based on the image data associated with the second wavelength; and

comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data.

9. The method of claim 8, further comprising determining the presence or absence of a particular material corresponding to the reference spectroscopic data.

10. The method of claim 8, wherein the first wavelength image data comprises image data corresponding to a plurality of pixels of the image, and wherein comparing the first wavelength image data to reference spectroscopic data comprises comparing first wavelength data for each of the plurality of pixels to the reference spectroscopic data.

11. The method of claim 8, wherein acquiring the first subframe image data associated with the first wavelength at the detector using the first exposure comprises acquiring the first subframe image data at a first integration time, and wherein acquiring the second subframe image data associated with the first wavelength at the detector using the second exposure comprises acquiring the first subframe image data at a second different integration time.

12. The method of claim 8, wherein acquiring the first subframe image data associated with the first wavelength at the detector using the first exposure comprises acquiring the first subframe image data using a first filter with a first attenuation, and wherein acquiring the second subframe image data associated with the first wavelength at the detector using the second exposure comprises acquiring the first subframe image data using a second filter with a second different attenuation.

13. The method of claim 8, wherein comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data comprises comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data corresponding to a plurality of different materials.

14. The method of claim 13, wherein the first wavelength image data comprises image data corresponding to a plurality of pixels of the image, and wherein comparing the first wavelength image data to reference spectroscopic data corresponding to the plurality of different materials comprises comparing first wavelength data for each of the plurality of pixels to the reference spectroscopic data for at least one of the different materials.

15. An infrared camera system comprising:

a filter holder configured to hold a first spike filter associated with a first wavelength and a second spike filter associated with a second wavelength, the filter holder further configured to position the first spike filter in the optical path of the infrared camera system for a first time interval and to position the second spike filter in the optical path of the infrared camera system for a second time interval;

a detection system configured to receive light from the first spike filter at a first exposure and to generate first subframe information indicative thereof, the detection system further configured to receive light from the first spike filter at a second exposure and to generate second subframe information indicative thereof, the detection system configured to receive light from the second spike filter at the first exposure and to generate third subframe information indicative thereof, the detection system further configured to receive light from the second spike filter at the second exposure and to generate fourth subframe information indicative thereof; and

a processor configured to receive the first subframe information and the second subframe information and to generate first superframe information associated with the first wavelength based on at least a part of the first subframe information and the second subframe information, the processor further configured to receive the third subframe information and the fourth subframe information and to generate second superframe information associated with the second wavelength based on at least a part of the third subframe information and the fourth subframe information, the processor further configured to compare the first superframe information and the second superframe information to reference spectroscopic data.

16. The system of claim 15, wherein the infrared camera comprises a near-infrared (NIR) camera.

17. The system of claim 15, further comprising a second filter holder configured to position a first filter in the optical path of the infrared camera system for the first exposure and to position a second different filter in the optical path of the infrared camera system for the second exposure.

18. The system of claim 15, wherein the processor is further configured to determine the presence or absence of a particular material corresponding to the reference spectroscopic data.

19. The system of claim 15, wherein the first superframe information comprises a first superframe information corresponding to a plurality of image pixels, and wherein comparing the first superframe information to reference spectroscopic information comprises comparing the first superframe information for each of the plurality of image pixels to the reference spectroscopic information.

20. The system of claim 15, wherein comparing the first superframe information and the second superframe information to reference spectroscopic data comprises comparing the first wavelength image data and the second wavelength image data to reference spectroscopic data corresponding to a plurality of different materials.