INFRARED RESOLUTION AND CONTRAST ENHANCEMENT WITH FUSION

• US 20120262584A1
• Filed: 04/02/2012
• Published: 10/18/2012
• Est. Priority Date: 04/23/2010
• 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 9,171,361 B2
• Time in Patent Office: Days
• US Class Current: 348/164
• CPC Class Codes: G06T 2207/10024 Color image
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 2207/20221 Image fusion; Image merging
• CPC Class Codes: G06T 5/50 using two or more images, e.g. averaging or subtraction
• CPC Class Codes: G06T 5/73 Deblurring; Sharpening
• CPC Class Codes: H04N 23/20 for generating image signals from infrared radiation only
• 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

The present disclosure relates to combination of images. A method according to an embodiment comprises: receiving a visual image and an infrared (IR) image of a scene and for a portion of said IR image extracting high spatial frequency content from a corresponding portion of said visual image. The method according to the embodiment further comprises combining said extracted high spatial frequency content from said portion of the visual image with said portion of the IR image, to generate a combined image, wherein the contrast and/or resolution in the portion of the IR image is increased compared to the contrast and/or resolution of said received IR image.

Claims

1. A method, comprising:

receiving a visual image and an infrared (IR) image of a scene;

for a portion of said IR image;

extracting high spatial frequency content from a corresponding portion of said visual image; and

combining said extracted high spatial frequency content from said portion of the visual image with said portion of the IR image, to generate a combined image, wherein the contrast and/or resolution in the portion of the IR image is increased compared to the contrast and/or resolution of said received IR image.

2. The method of claim 1, wherein the corresponding portion of the visual image is the portion that shows the same part of the observed real world scene as the portion of the IR image.

3. The method of claim 1, wherein the portion of said IR image is the entire IR image.

4. The method of claim 1, wherein said portion of the IR image and said corresponding portion of the visual image are scaled to a predetermined size.

5. The method of claim 4, wherein said predetermined size is a selection of:

the size of the captured IR image;

the size of the captured visual image; and

/or

the size of a display onto which the combined image is to be displayed.

6. The method of claim 1, further comprising receiving a control signal indicating a manual selection of a portion of said IR image.

7. The method of claim 1, wherein said portion of the IR image is a predetermined area in the IR image.

8. The method of claim 1, wherein the resolution of the visual image and the resolution of the IR image are substantially the same.

9. The method of claim 1, further comprising ensuring that a resolution for said portion of the visual image and said portion of the IR image are substantially the same.

10. The method of claim 1, further comprising checking whether a resolution for said portion of the visual image and said portion of the IR image are substantially the same;

and wherein, if the resolution for said portion of the visual image and said portion of the IR image are not substantially the same, altering a resolution of said portion of the visual image and/or a resolution of said portion of the IR image such that the resolution for said portion of the visual image and said portion of the IR image are substantially the same.

11. The method of claim 1, further comprising altering at least one of a resolution of said portion of said visual image and a resolution of said portion of said IR image such that said portion of the visual image and said portion of the IR image have substantially the same resolution.

12. The method of claim 1, further comprising up-sampling a resolution of said portion of said IR image to substantially a resolution of said portion of said visual image and/or down-sampling the resolution of said portion of said visual image to substantially the resolution of said portion of said IR image.

13. The method of claim 1, further comprising altering a resolution of said portion of said visual image and a resolution of said portion of said IR image to be substantially the same as a third resolution.

14. The method of claim 1, wherein a resolution of said portion of the IR image is 64×

64 pixels or less.

15. The method of claim 1, wherein a resolution of said portion of the IR image is 32×

32 pixels or less.

16. The method of claim 1, wherein the extracting high spatial frequency content from said portion of said visual image is performed by high pass filtering using at least one spatial filter.

17. The method of claim 1, further comprising processing said IR image to reduce noise in the IR image and/or smooth the IR image.

18. The method of claim 1, further comprising low pass filtering said IR image prior to the combining.

19. The method of claim 1, further comprising low pass filtering said IR image by use of a spatial filter prior to the combining.

20. The method of claim 1, wherein the combining comprises superimposing said extracted high spatial frequency content from said portion of said visual image on said portion of said IR image.

21. The method of claim 1, wherein the combining comprises superimposing said IR image on said extracted high spatial frequency content from said visual image.

22. The method of claim 1, wherein the combining comprises adding only a luminance component of said portion of said visual image to said portion of said IR image.

23. The method of claim 22, wherein the combining comprises adding a luminance component of said portion of said visual image multiplied by a factor to said portion of said IR image.

24. The method of claim 23, wherein said factor is variable based on a control parameter received from an input from a user.

25. The method of claim 1, further comprising adding high resolution noise to said combined image.

26. The method of claim 1, further comprising maintaining an IR palette for said IR image and/or for said combined image.

27. The method of claim 1, further comprising capturing a visual image and an IR image of a scene, and wherein the method of claim 1 is performed by an imaging device comprising an IR image capturing device and a visual image capturing device.

28. The method of claim 1, wherein the method is performed by a computer adapted to receive a visual image and an IR image of a scene.

32. The imaging device of claim 31, wherein the processing unit is further adapted to perform the method of claim 10.

29. A non-transitory computer program product for combining an IR image with a visual image, the computer program product comprising computer program code portions devised to control a data processing system to perform operations comprising:

receiving a visual image and an IR image of a scene;

for a portion of said IR image;

extracting high spatial frequency content from a corresponding portion of said visual image; and

combining said extracted high spatial frequency content from said portion of said visual image with said portion of said IR image, to generate a combined image, wherein the contrast in the selected portion of said IR image is increased compared to the contrast of said IR image.

30. The computer program product of claim 29, wherein the operations further comprise:

checking whether a resolution for said portion of the visual image and said portion of the IR image are substantially the same; and

wherein, if the resolution for said portion of the visual image and said portion of the IR image are not substantially the same, altering a resolution of said portion of the visual image and/or a resolution of said portion of the IR image such that the resolution for said portion of the visual image and said portion of the IR image are substantially the same.

31. An imaging device, comprising:

a visual image sensor for capturing a visual image;

an IR image sensor for capturing an IR image; and

a processing unit adapted to;

for a portion of said IR image;

extract high spatial frequency content from a corresponding portion of said visual image; and

combine said extracted high spatial frequency content from said portion of said visual image with said portion of said IR image, to generate a combined image, wherein the contrast in the selected portion of said IR image is increased compared to the contrast of said IR image.