Method and a system for processing and displaying images of the surroundings of an aircraft

• US 8,373,590 B1
• Filed: 12/21/2007
• Issued: 02/12/2013
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Airbus Helicopters
• Original Assignee: Eurocopter
• Inventors: Pir, Richard Edgard Claude
• Primary Examiner(s): GREGORY, BERNARR E
• Application Number:
  US11/962,143
• Time in Patent Office: 1,880 Days
• Field of Search: 342/27, 342/28, 342 70- 72, 342/175, 342/176, 342/179, 342/195, 342/29, 342 61- 66, 342118-123, 342/182, 701/300, 701/301, 701/1, 701/3, 382/100, 382/103, 348/61, 348/143, 348/148, 340/425.5, 340435-438, 340/459, 340/461, 340/945, 340/961, 340/963
• US Class Current: 342/29
• CPC Class Codes: G01C 23/005 Flight directors indicating arrangements specially adapted for rotary gyroscopes G01C19/32

Abstract

The invention relates to a method of processing an image sensed by an image sensor on board an aircraft fitted with an obstacle-locator system, in which the position and the extent of a zone in the sensed image, referred to as the zone of interest, is determined as a function of obstacle location data delivered by the obstacle-locator system, after which at least one parameter for modifying the brightness of points/pixels in said zone of interest is determined to enable the contrast to be increased in said zone of interest, and as a function of said modification parameter, the brightness of at least a portion of the image is modified.

Claims

1. A method of processing an image sensed by an image sensor on board an aircraft fitted with an obstacle-locator system, the method comprising:

determining in the sensed image as a function of obstacle location data delivered by the obstacle-locator system, wherein the zone corresponds to an obstacle indicated by the obstacle location data;

generating at least one parameter as a function of brightness of the zone; and

using said modification parameter to modify the brightness of the zone to increase contrast of the zone and thereby generate a modified image in which visibility of the zone is accentuated for presentation to crew of the aircraft.

2. A method according to claim 1, wherein the zone in the sensed image is determined as a function of the obstacle location data and as a function of navigation data delivered by an on-board navigation system.

3. A method according to claim 1, wherein at least part of the obstacle location data is obtained from telemetry measurements.

4. A method according to claim 1, wherein at least part of the obstacle location data is obtained from a database having at least one of terrain data and obstacle data.

5. A method according to claim 1, further comprising determining an outline for the zone, which outline is at least partially polygonal.

6. A method according to claim 1, further comprising determining an outline for the zone, which outline is at least partially curvilinear.

7. A method according to claim 1, wherein the zone is determined so that the bearing at the center of said zone is close to the bearing of the velocity vector of the aircraft.

8. A method according to claim 1, wherein the zone is determined so that the center of said zone is close to the center of the modified image.

9. A method according to claim 1, wherein the zone is determined so that a portion of the outline of said zone is close to a safety curve based on the obstacle location data and the current position and predicted trajectory of the aircraft.

10. A method according to claim 9, wherein the safety curve has zero guard height.

11. A method according to claim 1, wherein the image includes a plurality of pixels, wherein modifying the brightness of the zone to increase the contrast of the zone includes equalizing a histogram of pixel intensity in the zone for accentuating contrast in the zone.

12. A method according to claim 11, wherein distribution of pixel histograms is modified by a linear relationship that is a function of minimum and maximum brightness intensity of the pixels in the zone.

13. A method according to claim 11, wherein distribution of pixel histograms is modified by a multilinear relationship that is a function of minimum and maximum brightness intensity of the pixels in the zone.

14. A method according to claim 11, wherein distribution of pixel histograms is modified by a linear relationship that is a function of the standard deviation and of the average of the brightness intensity of pixels in the zone.

15. A method according to claim 1, further comprising applying the modification parameter to the entire sensed image.

16. A method according to claim 1, further comprising highlighting high spatial frequencies in the zone situated around a line joining together the tops of the obstacle.

17. A system for assisting the piloting of an aircraft, the system comprising:

an image sensor configured to generate an image of an environment of an aircraft;

an obstacle-locator system configured to generate obstacle location data indicative of obstacles in the environment of the aircraft;

a processor configured to receive the image and the obstacle location data and to determine a zone in the image as a function of the obstacle location data, wherein the zone corresponds to an obstacle indicated by the obstacle location data;

the processor further configured to generate a parameter as a function of brightness of the zone and use the modification parameter to modify the brightness of the zone to increase the contrast of the zone and thereby generate a modified image in which visibility of the zone is accentuated for presentation to crew of the aircraft.