Non-uniformity correction calibrations in infrared imaging systems and methods

Patent metadata

Field	Value
Publication number	US-12516987-B2
Application number	US-202217886368-A
Country	US
Kind code	B2
Filing date	Aug 11, 2022
Priority date	Aug 13, 2021
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

Techniques for facilitating non-uniformity correction calibrations are provided. In one example, an infrared imaging system includes an infrared imager and a logic device. The infrared imager is configured to capture a first set of infrared images of a reference object using a first integration time. The infrared imager is further configured to capture a second set of infrared images of the reference object using a second integration time different from the first integration time. The logic device is configured to determine a dark current correction map based on the second set of infrared images. The logic device is further configured to generate a non-uniformity correction map based on the dark current correction map. Related devices and methods are also provided.

First claim

What is claimed is:

1 . A method comprising:
capturing, by an imager of an imaging device, a first set of infrared images of a reference object using a first integration time; capturing, by the imager, a second set of infrared images of the reference object using a second integration time different from the first integration time; obtaining, from a memory of the imaging device, first and second image data associated with a two-source calibration of the imaging device, wherein the first image data is associated with a first reference source associated with a first temperature, and wherein the second image data is associated with a second reference source associated with a second temperature different from the first temperature; determining a dark current correction map based on the second set of infrared images, the first image data, and the second image data; and generating a non-uniformity correction map based on the dark current correction map.

2 . The method of claim 1 , wherein the dark current correction map is further based on the first integration time, and wherein the non-uniformity correction map is further based on the first set of infrared images.

3 . The method of claim 1 , further comprising capturing, by the imager, a third set of infrared images of the reference object using a third integration time, wherein the non-uniformity correction map is further based on the third set of infrared images.

4 . The method of claim 3 , further comprising:
capturing, by the imager, a fourth set of infrared images of the reference object using the third integration time; and determining the first integration time based on the third integration time and the fourth set of infrared images.

5 . A method comprising:
capturing, by an imager of an imaging device, a first set of infrared images of a reference object using a first integration time; capturing, by the imager, a second set of infrared images of the reference object using a second integration time different from the first integration time; capturing, by the imager, a third set of infrared images of the reference object using a third integration time; capturing, by the imager, a fourth set of infrared images of the reference object using the third integration time; determining the first integration time based on the third integration time and the fourth set of infrared images; determining a dark current correction map based on the second set of infrared images; generating a non-uniformity correction map based on the dark current correction map and the third set of infrared images; and determining a frame rate based on the first integration time and/or the third integration time, wherein the first, second, and third sets of images are captured according to the frame rate, and wherein the second integration time is lower than the first integration time and the third integration time.

6 . The method of claim 5 , wherein the frame rate is based on a longer of the first integration time or the third integration time.

7 . The method of claim 1 , further comprising obtaining, from the memory, third image data and the first integration time, wherein the third image data is associated with the second reference source and the first integration time, and wherein the dark current correction map is further based on the third image data and the first integration time.

8 . The method of claim 7 , wherein the second temperature is lower than the first temperature.

9 . The method of claim 1 , further comprising generating an offset map based on the dark current correction map, wherein the non-uniformity correction map comprises a gain map.

10 . The method of claim 1 , further comprising initiating a run-time calibration of the imager, wherein the run-time calibration comprises the capturing the first set, the capturing the second set, the determining, and the generating.

11 . The method of claim 1 , wherein the reference object is a shutter of the imaging device.

12 . An infrared imaging system comprising:
an infrared imager configured to:
capture a first set of infrared images of a reference object using a first integration time;
capture a second set of infrared images of the reference object using a second integration time different from the first integration time; and
capture a third set of infrared images using a third integration time; and
a logic device configured to:
determine a frame rate based on the first integration time and/or the third integration time, wherein the first set, second set, and/or third set of images are captured according to the frame rate;
determine a dark current correction map based on the second set of infrared images; and
generate a non-uniformity correction map based on the dark current correction map and the third set of images.

13 . The infrared imaging system of claim 12 , wherein:
the infrared imager is further configured to capture a fourth set of infrared images of the reference object using the third integration time; and the logic device is further configured to determine the first integration time based on the third integration time and the fourth set of infrared images.

14 . The infrared imaging system of claim 13 , wherein the second integration time is lower than the first integration time and the third integration time.

15 . The infrared imaging system of claim 12 , further comprising a memory configured to store calibration data associated with a two-source calibration, wherein the calibration data comprises first image data associated with a first source associated with a first temperature and second image data associated with a second source associated with a second temperature different from the first temperature, wherein the dark current correction map is further based on the first image data and the second image data.

16 . The infrared imaging system of claim 15 , wherein the calibration data further comprises third image data and the first integration time, wherein the third image data is associated with the second source and the third integration time, and wherein the dark current correction map is further based on the third image data and the first integration time.

17 . The infrared imaging system of claim 16 , wherein the second temperature is lower than the first temperature.

18 . The infrared imaging system of claim 12 , wherein the reference object is a shutter of the imaging system.

19 . The infrared imaging system of claim 12 , wherein the frame rate is based on a longer of the first integration time or the third integration time.

20 . The infrared imaging system of claim 12 , wherein the logic device is further configured to determine the first integration time based on the third integration time.

Assignees

• Teledyne Flir Commercial Systems Inc

Inventors

• Moreira Julie R
• Hoelter Theodore R

Classifications

• H04N5/33

  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) · CPC title

• H04N25/53

  Control of the integration time · CPC title

• H04N25/63

  applied to dark current · CPC title

• H04N25/671

  for non-uniformity detection or correction · CPC title

• G06T7/80

  Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration · CPC title