Infrared resolution and contrast enhancement with fusion

• US 9,471,970 B2
• Filed: 10/23/2015
• Issued: 10/18/2016
• 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: Strandmar, Katrin
• Primary Examiner(s): COUSO, YON JUNG
• Application Number:
  US14/922,076
• Publication Number:
  US 20160042503A1
• Time in Patent Office: 361 Days
• Field of Search: 382/263
• US Class Current: 1/1
• 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 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. An imaging system, comprising:

an infrared (IR) imaging device configured to capture an IR image representing a scene by colors or greyscale levels according to temperature;

a visual imaging device configured to capture a visual image of at least a portion of the scene; and

a processor configured to;

locate contours and/or edges from the visual image to obtain image data representing the located contours and/or edges; and

modify a luminance component of the IR image based on the image data representing the located contours and/or edges from the visual image to enhance the IR image, wherein the colors or the greyscale levels representing the scene for at least a portion of the IR image are unaltered by the modifying.

2. The imaging system of claim 1, wherein:

the IR image further comprises at least one color component; and

temperature variations in the scene is represented only by the at least one color component of the IR image, such that the temperature variations in the scene are shown unaltered in the IR image after the modifying.

3. The imaging system of claim 2, wherein the luminance component of the IR image captured by the IR imaging device is set to a constant value.

4. The imaging system of claim 1, wherein the IR image is a greyscale IR image representing temperature variations in the scene by the luminance component.

5. The imaging system of claim 1, wherein the IR imaging device or the processor is further configured to map IR image data for the scene captured by an IR imaging sensor to at least one color component of the IR image to represent the scene by the colors according to temperature.

6. The imaging system of claim 1, wherein:

the image data representing the located contours and/or edges from the visual image comprises luminance data for the located contours and/or edges; and

the processor is configured to modify the luminance component at least by adding the luminance data for the located contours and/or edges to the luminance component of the IR image.

7. The imaging system of claim 1, wherein:

the IR imaging device or the processor is configured to perform a color space transformation to determine the luminance and color components of the IR image according to a chosen color space.

8. The imaging system of claim 1, wherein the visual imaging device comprises a CCD, EMCCD, CMOS, or sCMOS imaging device.

9. The imaging system of claim 1, wherein the contours and/or edges located from the visual image comprise lines, visual patterns, contours, and/or edges of one or more objects in the scene.

10. The imaging system of claim 1, wherein the processor is configured to locate the contours and/or edges from the visual image at least by high-pass filtering the visual image to extract high-spatial frequency content comprising the contours and/or edges.

11. A method, comprising:

receiving an infrared (IR) image representing a scene by colors or greyscale levels according to temperature;

receiving a visual image of at least a portion of the scene;

locating contours and/or edges from the visual image to obtain image data representing the located contours and/or edges; and

modifying a luminance component of the IR image based on the image data representing the located contours and/or edges from the visual image to enhance the IR image, wherein the colors or the greyscale levels representing the scene for at least a portion of the IR image are unaltered by the modifying.

12. The method of claim 11, wherein:

the IR image further comprises at least one color component; and

temperature variations in the scene is represented only by the at least one color component of the IR image, such that the temperature variations in the scene are shown unaltered in the IR image after the modifying.

13. The method of claim 12, wherein the luminance component of the IR image prior to the modifying is set to a constant value.

14. The method of claim 11, wherein the IR image is a greyscale IR image representing temperature variations in the scene by the luminance component.

15. The method of claim 11, wherein the receiving of the IR image comprises mapping IR image data for the scene captured by an IR imaging sensor to at least one color component of the IR image to represent the scene by the colors according to temperature.

16. The method of claim 11, wherein:

the image data representing the located contours and/or edges from the visual image comprises luminance data for the located contours and/or edges; and

the modifying of the luminance component comprises adding the luminance data for the located contours and/or edges to the luminance component of the IR image.

17. The method of claim 11, wherein the receiving of the IR image comprises performing a color space transformation to determine the luminance and color components of the IR image according to a chosen color space.

18. The method of claim 17, wherein:

the chosen color space comprises a YCbCr color space; and

the color space transformation comprises a transformation of an RGB, HSV, CIE 1931 XYZ, or CIELab color space into the YCbCr color space.

19. The method of claim 11, wherein the contours and/or edges located from the visual image comprise lines, visual patterns, contours, and/or edges of one or more objects in the scene.

20. The method of claim 11, wherein the locating of the contours and/or edges comprises high-pass filtering the visual image to extract high-spatial frequency content comprising the contours and/or edges.