IP Library Granted Patent US 12,307,713
Granted Patent B2
US 12,307,713 · App. 17/456,924 · Granted May 20, 2025

Camera calibration method and apparatus and electronic device

Inventor: Zhenyou Dai (Guangdong, CN)
Assignee: AUTEL ROBOTICS CO., LTD.
G06T7/80G06T3/60G06T7/73H04N17/002G06T2207/10032G06T2207/30244
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Quick Facts
Patent No.
US 12,307,713
App. No.
17/456,924
Granted
May 20, 2025
Kind
B2
Abstract

Embodiments of the present invention relate to the field of unmanned aerial vehicle (UAV) technologies, and in particular, to a camera calibration method and apparatus and an electronic device. The method includes: obtaining a calibration image acquired by a camera on a calibration object, where the calibration object includes at least two basic units, and each basic unit has a different pattern; extracting feature points from the basic units of the calibration image, and obtaining pixel coordinates of the feature points; obtaining world coordinates of the feature points; and performing camera calibration according to the pixel coordinates and the world coordinates of the feature points.

Claims (45)

1. A camera calibration method, applicable to electronic device, and comprising:

obtaining a calibration image acquired by a camera on a calibration object, wherein the calibration object comprises at least two basic units, and each basic unit has a different pattern;

extracting feature points from the basic units of the calibration image, and obtaining pixel coordinates of the feature points;

obtaining world coordinates of the feature points;

performing camera calibration according to the pixel coordinates and the world coordinates of the feature points

displaying the calibration object on a display screen of the electronic device;

displaying an image acquisition position on the calibration object,

wherein

the image acquisition position is configured to guide the camera to acquire the calibration image;

the obtaining a calibration image acquired by a camera on a calibration object includes obtaining the calibration image acquired by the camera according to the image acquisition position,

wherein

the obtaining the calibration image acquired by the camera according to the image acquisition position includes obtaining a position of an intersection of an optical axis of the camera and a plane in which the display screen is located, and

obtaining an image acquired by the camera when the position of the intersection matches the image acquisition position as the calibration image of the image acquisition position; and

the displaying an image acquisition position on the calibration object includes displaying the image acquisition position on the calibration object, and sequentially displaying a next image acquisition position after the electronic device obtains the calibration image of the image acquisition position.

2. The method according to claim 1 , wherein the obtaining a calibration image acquired by a camera on a calibration object comprises:

obtaining a calibration image acquired by the camera on the calibration object at a first distance from the calibration object; and

obtaining a calibration image acquired by the camera on the calibration object at a second distance from the calibration object.

3. The method according to claim 1 , wherein the obtaining a position of an intersection of an optical axis of the camera and a plane in which the display screen is located comprises:

obtaining an initial calibration image acquired by the camera on the calibration object;

performing camera calibration according to the initial calibration image, to obtain an initial rotation matrix R and an initial translation vector t of a world coordinate system relative to a camera coordinate system; and

obtaining, according to the initial rotation matrix R and the initial translation vector t, the position of the intersection of the optical axis of the camera and the plane in which the display screen is located.

4. The method according to claim 1 , wherein the displaying the image acquisition position on the calibration object, and sequentially displaying a next image acquisition position after the electronic device obtains the calibration image of the image acquisition position comprises:

sequentially displaying image acquisition positions at the center and periphery of the calibration object.

5. A camera calibration apparatus, applicable to electronic device, wherein the apparatus comprises:

at least one processor; and a memory communicatively connected to the at least one processor, wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to cause the at least one processor to perform the following steps:

obtaining a calibration image acquired by a camera on a calibration object, wherein the calibration object comprises at least two basic units, and each basic unit has a different pattern;

extracting feature points from the basic units of the calibration image, and obtaining pixel coordinates of the feature points;

obtaining world coordinates of the feature points; and

performing camera calibration according to the pixel coordinates and the world coordinates of the feature points;

wherein the processor is further configured to:

display the calibration object on a display screen of the electronic device;

display an image acquisition position on the calibration object, wherein the image acquisition position is configured to guide the camera to acquire the calibration image;

obtain the calibration image acquired by the camera according to the image acquisition position;

obtain a position of an intersection of an optical axis of the camera and a plane in which the display screen is located;

obtain an image acquired by the camera when the position of the intersection matches the image acquisition position as the calibration image of the image acquisition position; and

display the image acquisition position on the calibration object, and sequentially display a next image acquisition position after the electronic device obtains the calibration image of the image acquisition position.

6. The apparatus according to claim 5 , wherein the processor is further configured to:

obtain a calibration image acquired by the camera on the calibration object at a first distance from the calibration object; and

obtain a calibration image acquired by the camera on the calibration object at a second distance from the calibration object.

7. The apparatus according to claim 5 , wherein the processor is further configured to:

obtain an initial calibration image acquired by the camera on the calibration object;

perform camera calibration according to the initial calibration image, to obtain an initial rotation matrix R and an initial translation vector t of a world coordinate system relative to a camera coordinate system; and

obtain, according to the initial rotation matrix R and the initial translation vector t, the position of the intersection of the optical axis of the camera and the plane in which the display screen is located.

8. The apparatus according to claim 5 , wherein the processor is further configured to:

sequentially display image acquisition positions at the center and periphery of the calibration object.

Assignments (1)
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Nov 30, 2021
From: DAI, ZHENYOU
To: AUTEL ROBOTICS CO., LTD.
Reel/Frame 058245/0662 →
Priority Claims (1)
CN 201910470300.9 · May 31, 2019 · national
Continuity (2)
Continuation PCTCN2020093433 · May 29, 2020
Related Publication 20220084246A1 · Mar 17, 2022
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