US-12625004-B2 - Detection threshold determination for infrared imaging systems and methods

Abstract

Techniques are provided for facilitating detection threshold determination for infrared imaging systems and methods. In one example, a method includes capturing, by an imaging device, a thermal image of a scene. The method further includes determining temperature difference data indicative of a difference between temperature data of the thermal image associated with a background of the scene and temperature data of the thermal image associated with gas detection. The method further includes determining detection threshold data based on sensitivity characteristics associated with the imaging device and the temperature difference data. The method further includes generating a detection threshold image based on the detection threshold data. Each pixel of the detection threshold image corresponds to a respective pixel of the thermal image and has a value indicative of a detection threshold associated with the respective pixel of the thermal image. Related devices and systems are also provided.

Inventors

• Henning Hagman
• Per Lilja

Assignees

• FLIR SYSTEMS AB

Dates

Publication Date

20260512

Application Date

20240531

Claims (20)

1. 1 . A method comprising: capturing, by an imaging device, a first thermal image of a scene; determining first temperature difference data indicative of a difference between temperature data of the first thermal image associated with a background of the scene and temperature data of the first thermal image associated with gas detection; determining first detection threshold data based on sensitivity characteristics associated with the imaging device and the first temperature difference data; and generating a first detection threshold image based on the first detection threshold data, wherein each pixel of the first detection threshold image corresponds to a respective pixel of the first thermal image and has a value indicative of a detection threshold associated with the respective pixel of the first thermal image.
2. 2 . The method of claim 1 , further comprising displaying the first detection threshold image.
3. 3 . The method of claim 1 , further comprising receiving user input, wherein the generating the first detection threshold image is in response to the user input.
4. 4 . The method of claim 1 , further comprising: receiving user input; and selectively displaying the first thermal image and/or the first detection threshold image in response to the user input.
5. 5 . The method of claim 1 , wherein, for each pixel of the first detection threshold image, the detection threshold is indicative of a concentration length threshold associated with the pixel.
6. 6 . The method of claim 1 , wherein the sensitivity characteristics comprise minimum resolvable temperature difference (MRTD) characteristics.
7. 7 . The method of claim 6 , wherein the MRTD characteristics comprise MRTD values for different spatial frequencies and/or different temperature spans for representing thermal image data of the first thermal image.
8. 8 . The method of claim 1 , further comprising determining spatial noise associated with the background, wherein the first detection threshold data is further based on the spatial noise.
9. 9 . The method of claim 1 , wherein the first thermal image of the scene is captured according to a first set of setup parameters, the method further comprising: capturing, by the imaging device, a second thermal image of the scene according to a second set of setup parameters; determining second temperature difference data indicative of a difference between temperature data of the second thermal image associated with the background of the scene and temperature data of the second thermal image associated with the gas detection; determining second detection threshold data based on the sensitivity characteristics associated with the imaging device and the second temperature difference data; and generating a second detection threshold image based on the second detection threshold data.
10. 10 . The method of claim 9 , wherein the first set of setup parameters comprises a position of the imaging device, a viewing angle of the imaging device, a temperature span represented in the first thermal image, and/or the background of the scene.
11. 11 . The method of claim 9 , wherein the first set of setup parameters comprises a first position of the imaging device when capturing the first thermal image, and wherein the second set of setup parameters comprises a second position of the imaging device when capturing the second thermal image.
12. 12 . The method of claim 1 , further comprising generating a temperature difference image based on the first temperature difference data, wherein each pixel of the temperature difference image corresponds to a respective pixel of the first thermal image and has a value indicative of a temperature difference associated with the respective pixel of the first thermal image.
13. 13 . The method of claim 12 , further comprising selectively displaying the first thermal image, the temperature difference image, and/or the first detection threshold image.
14. 14 . An infrared imaging system comprising: an infrared imager configured to capture a first thermal image of a scene; a logic device configured to: determine first temperature difference data indicative of a difference between temperature data of the first thermal image associated with a background of the scene and temperature data of the first thermal image associated with gas detection; determine first detection threshold data based on sensitivity characteristics associated with the infrared imager and the first temperature difference data; and generate a first detection threshold image based on the first detection threshold data, wherein each pixel of the first detection threshold image corresponds to a respective pixel of the first thermal image and has a value indicative of a detection threshold associated with the respective pixel of the first thermal image.
15. 15 . The infrared imaging system of claim 14 , further comprising a display device configured to selectively display the first thermal image and/or the first detection threshold image in response to user input.
16. 16 . The infrared imaging system of claim 14 , wherein, for each pixel of the first detection threshold image, the detection threshold is indicative of a concentration length threshold associated with the pixel.
17. 17 . The infrared imaging system of claim 14 , wherein the sensitivity characteristics comprise minimum resolvable temperature difference (MRTD) characteristics.
18. 18 . The infrared imaging system of claim 14 , wherein the logic device is further configured to determine spatial noise associated with the background, and wherein the first detection threshold data is further based on the spatial noise.
19. 19 . The infrared imaging system of claim 14 , wherein: the first thermal image of the scene is captured according to a first set of setup parameters; the first set of setup parameters comprises a position of the infrared imager, a viewing angle of the infrared imager, a temperature span represented in the first thermal image, and/or the background of the scene; the infrared imager is further configured to capturing a second thermal image of the scene according to a second set of setup parameters; and the logic device is further configured to: determine second temperature difference data indicative of a difference between temperature data of the second thermal image associated with the background of the scene and temperature data of the second thermal image associated with the gas detection; determine second detection threshold data based on the sensitivity characteristics associated with the infrared imager and the second temperature difference data; and generate a second detection threshold image based on the second detection threshold data.
20. 20 . The infrared imaging system of claim 14 , wherein the infrared imager comprises a plurality of microbolometers.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of International Patent Application No. PCT/US2022/051144 filed Nov. 29, 2022 and entitled “DETECTION THRESHOLD DETERMINATION FOR INFRARED IMAGING SYSTEMS AND METHODS,” which claims priority to and the benefit of U.S. Provisional Patent Application No. 63/285,987 filed Dec. 3, 2021 and entitled “DETECTION THRESHOLD DETERMINATION FOR INFRARED IMAGING SYSTEMS AND METHODS,” all of which are incorporated herein by reference in their entirety. TECHNICAL FIELD One or more embodiments relate generally to imaging and more particularly, for example, to detection threshold determination for infrared imaging systems and methods. BACKGROUND Imaging systems may include an array of detectors arranged in rows and columns, with each detector functioning as a pixel to produce a portion of a two-dimensional image. For example, an individual detector of the array of detectors captures an associated pixel value. There are a wide variety of image detectors, such as visible-light image detectors, infrared image detectors, or other types of image detectors that may be provided in an image detector array for capturing an image. As an example, a plurality of sensors may be provided in an image detector array to detect electromagnetic (EM) radiation at desired wavelengths. In some cases, such as for infrared imaging, readout of image data captured by the detectors may be performed in a time-multiplexed manner by a readout integrated circuit (ROIC). The image data that is read out may be communicated to other circuitry, such as for processing, storage, and/or display. In some cases, a combination of a detector array and an ROIC may be referred to as a focal plane array (FPA). Advances in process technology for FPAs and image processing have led to increased capabilities and sophistication of resulting imaging systems. SUMMARY In one or more embodiments, a method includes capturing, by an imaging device, a thermal image of a scene. The method further includes determining temperature difference data indicative of a difference between temperature data of the thermal image associated with a background of the scene and temperature data of the thermal image associated with gas detection. The method further includes determining detection threshold data based on sensitivity characteristics associated with the imaging device and the temperature difference data. The method further includes generating a detection threshold image based on the detection threshold data. Each pixel of the detection threshold image corresponds to a respective pixel of the thermal image and has a value indicative of a detection threshold associated with the respective pixel of the thermal image. In one or more embodiments, an infrared imaging system includes an infrared imager configured to capture a thermal image of a scene. The infrared imaging system further includes a logic device configured to determine temperature difference data indicative of a difference between temperature data of the thermal image associated with a background of the scene and temperature data of the thermal image associated with gas detection. The logic device is further configured to determine detection threshold data based on sensitivity characteristics associated with the infrared imager and the temperature difference data. The logic device is further configured to generate a detection threshold image based on the detection threshold data. Each pixel of the detection threshold image corresponds to a respective pixel of the thermal image and has a value indicative of a detection threshold associated with the respective pixel of the thermal image. The scope of the present disclosure is defined by the claims, which are incorporated into this section by reference. A more complete understanding of embodiments of the present disclosure will be afforded to those skilled in the art, as well as a realization of additional advantages thereof, by a consideration of the following detailed description of one or more embodiments. Reference will be made to the appended sheets of drawings that will first be described briefly. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 illustrates a block diagram of an example imaging system in accordance with one or more embodiments of the present disclosure. FIG. 2 illustrates a block diagram of an example image sensor assembly in accordance with one or more embodiments of the present disclosure. FIG. 3 illustrates a schematic view of imaging of gas in accordance with one or more embodiments of the present disclosure. FIG. 4 illustrates an example system for facilitating detection threshold determination and other imaging processes in accordance with one or more embodiments of the present disclosure. FIG. 5 illustrates a graph of sensitivity characteristics that characterize an imaging system in accordance with one or more embodiments of the present disclosure. FIG. 6A illustrates an example therm