Image enhancement in far infrared camera

• US 20030218676A1
• Filed: 05/23/2002
• Published: 11/27/2003
• Est. Priority Date: 05/23/2002
• Status: Active Grant

• Current Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Original Assignee: Visteon Global Technologies Incorporated (Visteon Corporation)
• Inventors: Miyahara, Shunji
• Granted Patent: US 6,759,949 B2
• Time in Patent Office: Days
• US Class Current: 348/148
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10048 Infrared image
• CPC Class Codes: G06T 2207/20012 Locally adaptive
• CPC Class Codes: G06T 2207/30261 Obstacle
• CPC Class Codes: G06T 5/94 based on local image properties, e.g. for local contrast enhancement
• CPC Class Codes: G06T 7/136 involving thresholding
• 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 invention is an infrared imaging system that comprises a far-infrared camera disposed at the front end of a vehicle adapted for detecting thermal radiation in the 7 to 14 micron wavelength band and producing an image signal indicative of the temperature of the surrounding objects. A digital signal processor receives the image signal and selectively enhances the temperature resolution based upon the relative temperature distribution of the image signal, which is proportional to the temperature of objects emitting in the infrared region. In accordance with the present invention, the digital signal processor enhances temperature ranges having high concentrations and contracts temperature ranges having low concentrations. The digital signal processor selects between high and low concentrations based upon a predetermined threshold concentration value. A display apparatus receives a display signal that is temperature-enhanced and displays that signal to the driver.

Claims

1. An infrared imaging system for a vehicle comprising:

an infrared camera disposed at a front end of the vehicle, said infrared camera adapted for receiving a spectrum of radiation and producing an image signal in response thereto,

a digital signal processor adapted for receiving said image signal and processing said image signal thereby creating a display signal,

whereby said digital signal processor processes said image signal by calculating an intensity distribution of said image signal, discerning a maximum value of said intensity distribution, and by mapping said image signal into said display signal such that said display signal is thermally enhanced.

2. The infrared imaging system of claim 1 further comprising a display for viewing by a vehicle operator.

3. The infrared imaging system of claim 2 wherein said display is a head-up display.

4. The infrared imaging system of claim 2 wherein said display is a video monitor.

5. The infrared imaging system of claim 1 wherein said infrared camera is adapted to detect radiation in a range from 7 microns to 14 microns.

6. The infrared imaging system of claim 1 wherein said digital signal processor compares said maximum value of said intensity distribution to a threshold concentration value.

7. The infrared imaging system of claim 6 wherein in response to said maximum value of said intensity distribution being greater than said threshold concentration value, said digital signal processor temperature enhances said image signal.

8. The infrared imaging system of claim 7 wherein in enhancing said image signal, said digital signal processor expands a region high intensity and contracts a region of low intensity such that said region of high intensity is temperature enhanced.

9. A vehicle having an infrared imaging system, said vehicle comprising:

an infrared camera disposed at a front end of said vehicle, said infrared camera adapted for receiving a spectrum of radiation and producing an image signal in response thereto;

a display disposed within said vehicle;

a digital signal processor receiving said image signal, calculating an intensity distribution of said image signal, discerning a maximum value of said intensity distribution, and by mapping said image signal into said display signal such that said display signal is thermally enhanced;

whereby a thermally-enhanced display signal is transmitted to said display such that a thermally-enhanced infrared image is displayable within a passenger compartment of said vehicle.

10. The vehicle of claim 9 wherein said display is a head-up display.

11. The vehicle of claim 9 wherein said display is a video monitor.

12. The vehicle of claim 9 wherein said infrared camera is adapted to detect radiation in a range from 7 microns to 14 microns.

13. The vehicle of claim 9 wherein said digital signal processor compares said maximum value of said intensity distribution to a threshold concentration value.

14. The vehicle of claim 13 wherein in response to said maximum value of said intensity distribution being greater than said threshold concentration value, said digital signal processor temperature enhances said image signal.

15. The vehicle of claim 14 wherein in enhancing said image signal, said digital signal processor expands a region high intensity and contracts a region of low intensity such that said region of high intensity is temperature enhanced.

16. A method for enhancing the thermal imaging resolution of an infrared camera for a vehicle, said method comprising:

receiving a spectrum of radiation and producing an image signal in response thereto,

discerning a maximum value of said image signal,

comparing said maximum value to a threshold value;

transforming said thermally-enhanced said display signal in response to said maximum value being greater than said threshold value.

17. The method of claim 16 further comprising the step of displaying said display signal in a passenger compartment of said vehicle.

18. The method of claim 17 wherein the step of displaying said display signal in a passenger compartment includes displaying said display signal using a head-up display.

19. The method of claim 17 wherein the step of displaying said display signal in a passenger compartment includes displaying said display signal using a video monitor.