GAS VISUALIZATION ARRANGEMENTS, DEVICES, AND METHODS

• US 20130113939A1
• Filed: 11/06/2012
• Published: 05/09/2013
• Est. Priority Date: 11/07/2011
• Status: Active Grant

• Current Assignee: Flir Systems AB (Teledyne Technologies Incorporated)
• Original Assignee: Flir Systems AB (Teledyne Technologies Incorporated)
• Inventors: Strandemar, Katrin
• Granted Patent: US 9,280,812 B2
• Time in Patent Office: Days
• US Class Current: 348/164
• CPC Class Codes: G01N 21/3504 for analysing gases, e.g. multi-gas analysis
• CPC Class Codes: G06T 11/001 Texturing; Colouring; Generation of texture or colour inpainting G06T5/77
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 2207/20056 Discrete and fast Fourier transform, [DFT, FFT]
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 2207/20224 Image subtraction
• CPC Class Codes: G06T 5/10 using non-spatial domain filtering
• CPC Class Codes: G06T 5/20 using local operators
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 7/0008 checking presence/absence
• CPC Class Codes: G06T 7/13 Edge detection
• CPC Class Codes: G06T 7/174 involving the use of two or more images
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths
• CPC Class Codes: H04N 23/631 Graphical user interfaces [GUI] specially adapted for controlling image capture or setting capture parameters
• 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

Gas visualization in an image depicting a scene, for an example embodiment comprises capturing a first IR image depicting the scene at a first time instance and a second IR image depicting the scene at a second time instance; performing image processing operations on image data derived from said first IR image and from said second IR image, to generate a collection of data representing the location of gas in one of the first or second IR images; and generating a third image by adjusting pixel values in an image depicting the scene, dependent on pixel values of said collection of data. According to various embodiments, there is further provided further processing of the collection of data, and/or gas detection, before generation of the third image with adjusted pixel values.

Claims

1. ) A method for gas visualization in an infrared (IR) image depicting a scene, the method comprising:

capturing a first IR image depicting the scene at a first time instance and a second IR image depicting the scene at a second time instance;

performing image processing operations on image data derived from said first IR image and from said second IR image, to generate a collection of data representing the location of gas in one of the first or second IR image; and

generating a third image by adjusting pixel values in an image depicting the scene, dependent on pixel values of said collection of data.

2. ) The method of claim 1, wherein the operations to generate a collection of data representing the location of gas comprise generating a temporal difference image based on the first IR image and the second IR image.

3. ) The method of claim 2, wherein the operations to generate a collection of data representing the location of gas comprise further processing of said difference image before generating said third image, wherein said processing of the difference image comprises:

transforming the difference image into the frequency domain by an FFT operation or a PSD operation; and

/or

low pass filtering the difference image.

4. ) The method of claim 3, further comprising:

detecting gas within the scene by detecting gas representing pixels in the first or second IR images based on said difference image; and

generating said third image by adjusting, in an image depicting the scene, pixel values of pixels corresponding to the gas representing pixels in one of said first or second IR image, such that the gas representing pixels are distinguishable.

5. ) The method of claim 3, wherein the transformation of the difference image into the frequency domain is performed block wise, using image blocks of a size smaller than the size of the difference image, and/or as a sub-portion of the pixels of the difference image, thereby resulting in a down-sampled frequency domain image.

6. ) The method of claim 1, further comprising detecting gas within the scene before generating said third image, or gas visualization image, by detecting gas representing pixels in the first or second IR image based on said collection of data.

7. ) The method of claim 2, wherein generating a collection of data representing the location of gas in one of the first or second IR image comprises creating a gas map comprising the detected gas information in the form of a binary gas image.

8. ) The method of claim 1, further comprising:

performing edge detection in at least one of the first and the second IR image;

creating an edge map comprising the detected edge information, wherein the pixels representing detected edge information are assigned a first pixel value and the remaining pixels are assigned a second pixel value; and

generating a processed difference image by combining the edge map with the difference image such that the detected edge information is removed.

9. ) The method of claim 8, wherein the edge map is in the form of a binary edge image and the generating a processed difference image comprises a selection of:

subtracting the binary image from the difference image;

or

multiplying the binary image with the difference image.

10. ) The method of claim 8, further comprising:

expanding the detected edges before generating the processed difference image; and

detecting gas by selecting in the temporal difference image pixels representing gas present in the scene based on said collection of gas location representing data.

11. ) The method of claim 4, wherein detecting gas is performed in the transformed difference image, to identify pixel coordinates of pixels representing gas present in the scene, and wherein the gas detection comprises thresholding the pixels of the transformed difference image.

12. ) The method of claim 4, wherein the third image is generated by adjusting, in an IR image depicting the scene, the pixel values of pixels corresponding to the detected gas representing pixels, the IR image depicting the scene being a selection of:

the first IR image;

the second IR image; and

another IR image depicting the scene.

13. ) The method of claim 7, wherein the third image is generated by:

adjusting, in a visual image depicting the scene, the pixel values of pixels corresponding to the detected gas representing pixels, said visual image having a predetermined relation to the first and second IR images;

adjusting, in the generated temporal difference image, the pixel values of pixels corresponding to the detected gas representing pixels; and

/or

combining the gas map with the difference image such that pixels corresponding to the pixels that have been identified as representing gas information in the gas map are assigned the pixel values of the corresponding pixels in the difference image, to generate an intermediate gas image.

14. ) An infrared (IR) imaging arrangement, comprising:

an infrared sensor configured to capture infrared image data depicting a scene;

a processor configured to receive and process infrared image data from said infrared sensor, the processor being further adapted to;

receive a first IR image depicting the scene and being captured at a first time instance;

receive a second IR image depicting the scene and being captured at a second time instance;

perform image processing operations on image data derived from the first and second IR images to generate a collection of data representing the location of gas in one of the first or second IR images; and

generate a third image by adjusting pixel values, in an image depicting the scene, dependent on pixel values of the collection of data.

15. ) The infrared (IR) imaging arrangement of claim 14, further comprising a visible light imaging sensor adapted to capture a visual light image depicting the scene and having a predetermined relation to said first and second IR images, and wherein the processor is coupled to the infrared sensor.

16. ) The infrared (IR) imaging arrangement of claim 14, wherein the processor is a field-programmable gate array (FPGA).

17. ) The infrared (IR) imaging arrangement of claim 14, wherein the operations to generate a collection of data representing the location of gas comprise generating a temporal difference image based on the first IR image and the second IR image, and wherein the operations to generate a collection of data representing the location of gas comprise further processing of said difference image before generating said third image, wherein said processing of the difference image comprises:

transforming the difference image into the frequency domain by an FFT operation or a PSD operation; and

/or

low pass filtering the difference image.

18. ) A computing system configured to process infrared (IR) image data, the computing system comprising:

a memory configured to store infrared image data depicting a scene;

a processor configured to process infrared image data stored in the memory, the processor being further adapted to;

receive from the memory a first IR image depicting the scene captured at a first time instance;

receive from the memory a second IR image depicting the scene captured at a second time instance;

perform image processing operations on image data derived from the first and second IR images to generate a collection of data representing the location of gas in one of the first or second IR images; and

generate a third image by adjusting pixel values, in an image depicting the scene, dependent on pixel values of the collection of data.

19. ) The computing system of claim 18, wherein the processor is a field-programmable gate array.

20. ) The computing system of claim 18, further comprising:

performing edge detection in at least one of the first and the second IR image;

creating an edge map comprising the detected edge information, wherein the pixels representing detected edge information are assigned a first pixel value and the remaining pixels are assigned a second pixel value;

generating a processed difference image by combining the edge map with the difference image such that the detected edge information is removed;

expanding the detected edges before generating the processed difference image; and

detecting gas by selecting in the temporal difference image pixels representing gas present in the scene based on said collection of gas location representing data.