METHOD OF DETERMINING A DURATION OF EXPOSURE OF A CAMERA ON BOARD A DRONE, AND ASSOCIATED DRONE

• US 20170078553A1
• Filed: 09/07/2016
• Published: 03/16/2017
• Est. Priority Date: 09/14/2015
• Status: Abandoned Application

• Current Assignee: Parrot Drones
• Original Assignee: Parrot Drones
• Inventors: Pochon, Benoit, Sron, Eng Hong
• Application Number:
  US15/258,936
• Publication Number:
  US 20170078553A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B64U 2101/30 for imaging, photography or videography
• CPC Class Codes: G06T 2207/10016 Video; Image sequence
• CPC Class Codes: G06T 2207/10032 Satellite or aerial image; Remote sensing
• CPC Class Codes: G06T 2207/30241 Trajectory
• CPC Class Codes: G06T 7/80 Analysis of captured images to determine intrinsic or extrinsic camera parameters, i.e. camera calibration
• CPC Class Codes: H04N 23/70 Circuitry for compensating brightness variation in the scene
• CPC Class Codes: H04N 23/71 Circuitry for evaluating the brightness variation
• CPC Class Codes: H04N 23/73 by influencing the exposure time

Abstract

The invention relates to a method of dynamically determining the duration of exposure for the capture of an image implemented in a drone comprising a substantially vertical-view camera. The method comprises a step (21) of measuring of the horizontal speed of displacement of the drone, a step (22) of measuring the distance between said drone and the ground, and a step (23) of determining the duration of exposure based on the measured speed of displacement of the drone, the distance measured between said drone and the ground, a predetermined quantity of blurring and the focal length of said camera.

Claims

1. A method of dynamically determining the duration of exposure for the capture of an image implemented in a drone, comprising a substantially vertical-view camera, characterized in that it comprises:

a step (21) of measuring the horizontal speed of displacement of the drone,

a step (22) of measuring the distance between said drone and the ground (Z), and

a step (23) of determining the duration of exposure based on the measured speed of displacement of the drone, the distance measured between said drone and the ground (Z), a predetermined quantity of blurring (du) and the focal length (f) of said camera.

2. The method of determining according to claim 1, characterized in that the duration of exposure (T_exp) is defined by:

3. The method of determining according to claim 1, characterized in that the method further comprises a step of determining a second duration of exposure (24) based on the focal length (f) of said camera, a predetermined quantity of blurring (du) and the speed of rotation (ω

) of said drone.

4. The method of determining according to claim 3, characterized in that the second duration of exposure (T_exp) is defined by:

5. The method of determining according to claim 4, characterized in that the quantity of blurring (du) is determined by the displacement of the scene in the image plane between the instant of beginning and the instant of end of the exposure.

6. The method of determining according to claim 5, characterized in that the focal length of said camera and the quantity of blurring are expressed in pixels.

7. The method of determining according to claim 6, characterized in that the focal length expressed in pixels (f_pixel) is defined by:

10. The method of determining according to claim 2, characterized in that the method further comprises a step of determining a second duration of exposure (24) based on the focal length (f) of said camera, a predetermined quantity of blurring (du) and the speed of rotation (ω

) of said drone.

11. The method of determining according to claim 4, characterized in that the focal length of said camera and the quantity of blurring are expressed in pixels.

8. A method of dynamically determining the duration of exposure for the capture of an image implemented in a drone, comprising a substantially vertical-view camera, characterized in that the method comprises a step of determining the effective duration of exposure, said effective duration of exposure being the minimum duration between

a first duration of exposure determined by

a step (21) of measuring the horizontal speed of displacement of the drone,

a step (22) of measuring the distance between said drone and the ground (Z), and

a step (23) of determining the duration of exposure based on the measured speed of displacement of the drone, the distance measured between said drone and the ground (Z), a predetermined quantity of blurring (du) and the focal length (f) of said camera;

and

a second duration of exposure determined based on the focal length (f) of said camera, a predetermined quantity of blurring (du) and the speed of rotation (ω

) of said drone.

12. The method of determining according to claim 8, characterized in that the first duration of exposure (T_exp) is defined by:

13. The method of determining according to claim 8, characterized in that the second duration of exposure (T_exp) is defined by:

14. The method of determining according to claim 13, characterized in that the quantity of blurring (du) is determined by the displacement of the scene in the image plane between the instant of beginning and the instant of end of the exposure.

15. The method of determining according to claim 14, characterized in that the focal length of said camera and the quantity of blurring are expressed in pixels.

16. The method of determining according to claim 15, characterized in that the focal length expressed in pixels (f_pixel) is defined by:

9. A drone comprising a substantially vertical-view camera adapted to implement a method of dynamically determining a duration of exposure for capture of an image by said camera by:

measuring horizontal speed of displacement of the drone,

measuring distance between said drone and the ground (Z), and

determining duration of exposure based on the measured speed of displacement of the drone, the distance measured between said drone and the ground (Z), a predetermined quantity of blurring (du) and the focal length (f) of said camera.

17. The drone according to claim 9, characterized in that the duration of exposure (T_exp) is defined by:

18. The drone according to claim 9, characterized in that the method further comprises determining a second duration of exposure (24) based on the focal length (f) of said camera, a predetermined quantity of blurring (du) and the speed of rotation (ω

) of said drone.

19. The drone according to claim 18, characterized in that the second duration of exposure (T_exp) is defined by:

20. The drone according to claim 19, characterized in that the quantity of blurring (du) is determined by the displacement of the scene in the image plane between the instant of beginning and the instant of end of the exposure.

21. The drone according to claim 20, characterized in that the focal length of said camera and the quantity of blurring are expressed in pixels.

22. The drone according to claim 21, characterized in that the focal length expressed in pixels (f_pixel) is defined by: