Methods for producing a temperature map of a scene

• US 10,694,120 B2
• Filed: 10/02/2018
• Issued: 06/23/2020
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Original Assignee: DRS Network & Imaging Systems, LLC (Leonardo S.p.A.)
• Inventors: Southerland, Richard L., Blettner, Douglas A., Hutchison, David C., Neal, Henry W.
• Primary Examiner(s): Carter, Aaron W
• Application Number:
  US16/150,126
• Publication Number:
  US 20190110005A1
• Time in Patent Office: 630 Days
• CPC Class Codes: G01J 2005/0077 Imaging
• CPC Class Codes: G01J 5/025 Interfacing a pyrometer to an external device or network; User interface
• CPC Class Codes: G01J 5/0806 Focusing or collimating elements, e.g. lenses or concave mirrors
• CPC Class Codes: G01J 5/10 using electric radiation detectors
• CPC Class Codes: G01J 5/48 Thermography; Techniques using wholly visual means
• CPC Class Codes: G06T 3/40 Scaling of whole images or parts thereof, e.g. expanding or contracting
• CPC Class Codes: G06T 5/00 Image enhancement or restoration
• CPC Class Codes: G06T 5/90 Dynamic range modification of images or parts thereof
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 21/23439 for generating different versions
• CPC Class Codes: H04N 21/23605 Creation or processing of packetized elementary streams [PES]
• CPC Class Codes: H04N 21/23614 Multiplexing of additional data and video streams arrangements for simultaneous broadcast of plural pieces of information H04H20/28
• CPC Class Codes: H04N 21/4348 Demultiplexing of additional data and video streams
• 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

Methods for generating a temperature map of a scene are provided. A method may include receiving thermal data of the scene. The thermal data includes frames of thermal infrared data. A mapping may be created for each frame based on the digital thermal infrared data. The method further includes generating the temperature map using the mapping. The temperature map is generated prior to a contrast enhancement process. The method further includes separately transmitting the temperature map and the digital thermal infrared data in a data channel.

Claims

1. A method of generating a temperature map, the method comprising:

receiving analog infrared light data of a scene;

converting the analog infrared light data from analog to digital format to create digital infrared light data, the digital infrared light data comprising a plurality of frames, each frame comprising a plurality of pixels;

computing, by a processor and for each frame, a correction array having a plurality of correction pixel values, wherein each correction pixel value is created by;

determining a correction pixel value for a neighbor pixel value of a neighbor pixel;

computing a difference between a first correction value of a pixel value of a pixel and a correction pixel value for the neighbor pixel value, wherein the neighbor pixel is adjacent to the pixel; and

updating the correction pixel value using the difference;

updating each frame based on the respective correction array;

creating a lookup table for each frame of the plurality of frames based on the digital infrared light data;

generating a temperature map using the lookup table; and

separately transmitting the temperature map and the digital infrared light data in a data channel.

2. The method of claim 1, wherein the pixel and the neighbor pixel are associated with an object.

3. The method of claim 1, wherein computing the difference comprises computing an additional difference between the first correction value and the correction pixel value for the neighbor pixel.

4. The method of claim 1, wherein computing the correction array further comprises determining that an absolute value of the difference is within a range.

5. The method of claim 1, wherein computing the correction array further comprises:

adding a fraction of the difference to a previous neighbor correction value to update a neighbor correction value; and

subtracting the fraction of the difference from a previous correction value to update a correction value.

6. The method of claim 1, wherein the correction pixel value is a summation of the pixel value and a previous correction value, and wherein the correction pixel value for each neighbor pixel value is a second summation of the neighbor pixel value and a previous neighbor correction value.

7. The method of claim 1, further comprising integrating the plurality of frames at a frame rate, thereby creating integrated digital video data.

8. The method of claim 7, further comprising:

adjusting a gain of the integrated digital video data at the frame rate using an automatic gain control to generate an adjusted digital video data;

selecting a video output from at least two of the adjusted digital video data, the digital infrared light data, or the integrated digital video data to create a multiplexed video output; and

separately transmitting the temperature map and the multiplexed video output in the data channel.

9. The method of claim 7, further comprising:

detecting light data of the scene at a first frame rate, wherein a second frame rate of the integrated digital video data is lower than the first frame rate; and

transmitting the temperature map at a third frame rate, wherein the third frame rate is lower than the second frame rate, wherein the temperature map is transmitted at the third frame rate separately from the digital infrared light data in the data channel.

10. The method of claim 1, further comprising:

receiving a plurality of frames of non-thermal light data;

converting the plurality of frames of non-thermal light data from analog to digital format to create digital visible light data; and

transmitting the plurality of frames of non-thermal light data in the data channel.

16. The method of claim 10, wherein the non-thermal light data includes visible light data.

11. A method of generating a temperature map, the method comprising:

receiving analog infrared light data of a scene;

converting the analog infrared light data from analog to digital format to create digital infrared light data, the digital infrared light data comprising a plurality of frames, each frame comprising a plurality of pixels;

replacing a pixel of the plurality of pixels in the digital infrared light data by;

determining that the pixel is outside a range of a statistical metric based on one or more additional neighbor pixels that are adjacent to the pixel, and

substituting the pixel with information gathered from the one or more additional neighbor pixels;

creating a lookup table for each frame of the plurality of frames based on the digital infrared light data;

generating a temperature map using the lookup table; and

separately transmitting the temperature map and the digital infrared light data in a data channel.

12. The method of claim 11, further comprising:

receiving a plurality of frames of non-thermal light data;

converting the plurality of frames of non-thermal light data from analog to digital format to create digital visible light data; and

transmitting the plurality of frames of non-thermal light data in the data channel.

13. The method of claim 11, wherein each frame comprises a plurality of pixels, the method further comprising:

computing, by a processor and for each frame, a correction array having a plurality of correction pixel values, wherein each correction pixel value is created by;

determining a neighbor correction pixel value for a neighbor pixel value of a neighbor pixel;

computing a difference between a correction value of a pixel value of a pixel and the neighbor correction pixel value, wherein the neighbor pixel is adjacent to the pixel; and

updating the correction pixel value using the difference; and

updating each frame based on the respective correction array.

14. The method of claim 13, wherein the correction value of the pixel value is a first summation of the pixel value and a previous correction value, and wherein the correction value for each neighbor pixel value is a second summation of the neighbor pixel value and a previous neighbor correction value.

15. The method of claim 13, further comprising calibrating the lookup table using non-uniformity correction on the digital infrared light data.

17. The method of claim 12, wherein the non-thermal light data includes visible light data.