METHOD OF ACQUIRING HORIZONTAL DISTANCE BETWEEN CAMERA AND TARGET, AND CAMERA AND SURVEILLANCE SYSTEM ADOPTING THE METHOD

• US 20140152810A1
• Filed: 06/17/2013
• Published: 06/05/2014
• Est. Priority Date: 12/03/2012
• Status: Active Grant

• Current Assignee: Hanwha Robotics Corporation
• Original Assignee: Samsung Techwin Corporation (Hanwha Corporation)
• Inventors: BAE, Soon-Min
• Granted Patent: US 9,766,067 B2
• Time in Patent Office: Days
• US Class Current: 348/135
• CPC Class Codes: G01C 11/025 by scanning the object
• CPC Class Codes: G01C 3/12 with monocular observation at a single point, e.g. coincidence type G01C3/20 takes precedence

Abstract

Exemplary embodiments disclose a method of acquiring a horizontal distance between a camera and a target, which is a horizontal distance between a central point of an optical system of the camera and a ground landing point of the target. The method includes acquiring a relative target angle using an angle between a ground and a camera-target connection line which connects the central point of the optical system of the camera and the ground landing point of the target, acquiring a height of the camera using a height of the central point of the optical system of the camera on a basis of a vertical position of the ground landing point of the target, and setting a quotient of the height of the camera divided by a tangent value of the relative target angle as the horizontal distance between the camera and the target.

Claims

1. A method of acquiring a horizontal distance between a camera and a target, which is a horizontal distance between a central point of an optical system of the camera and a ground landing point of the target, the method comprising:

acquiring a relative target angle using an angle between a ground and a camera-target connection line which connects the central point of the optical system of the camera and the ground landing point of the target;

acquiring a height of the camera using a height of the central point of the optical system of the camera on a basis of a vertical position of the ground landing point of the target; and

setting a quotient of the height of the camera divided by a tangent value of the relative target angle as the horizontal distance between the camera and the target.

2. The method of claim 1, wherein the acquiring the relative target angle comprises:

acquiring a ground-camera angle using an angle between the ground and an optical axis of the optical system of the camera;

acquiring a camera-target angle using an angle by which the camera-target connection line is placed away from the optical axis of the camera; and

acquiring the relative target angle according to the ground-camera angle and the camera-target angle.

3. The method of claim 2, wherein a tilting angle acquired in a tilting control of the camera is set as the ground-camera angle.

4. The method of claim 2, wherein, if the ground-camera angle is 0 degree when the camera is parallel to the ground, the camera-target angle is set as the relative target angle.

5. The method of claim 4, wherein, if the ground-camera angle includes the camera-target angle, the relative target angle is equal to the ground-camera angle minus the camera-target angle.

6. The method of claim 5, wherein, if the camera-target angle includes the ground-camera angle, the relative target angle is equal to the camera-target angle minus the ground-camera angle.

7. The method of claim 6, wherein, if the ground-camera angle does not include the camera-target angle, and the camera-target angle does not include the ground-camera angle, the relative target angle is equal to the ground-camera angle minus the camera-target angle.

8. The method of claim 2, wherein the camera includes a photoelectric conversion device corresponding to the optical system, and

wherein the acquiring the ground-camera angle comprises:

acquiring a vertical coordinate of a sensor central point, if the optical axis of the optical system of the camera is extended toward the photoelectric conversion device in a straight line, the sensor central point being a point where the extended optical axis reaches the photoelectric conversion device;

acquiring a vertical coordinate of a sensor horizontal point, if a straight line parallel to the ground is extended from the central point of the optical system of the camera, the sensor horizontal point being a point where the extended line reaches the photoelectric conversion device;

acquiring a sensor tilting distance, which is a vertical distance between the sensor central point and the sensor horizontal point; and

acquiring a quotient of the sensor tilting device divided by a focal distance of the optical system, and setting an arctangent value of the quotient as the ground-camera angle.

9. The method of claim 2, wherein the camera includes a photoelectric conversion device corresponding to the optical system, and

wherein the acquiring the camera-target angle comprises:

acquiring a vertical coordinate of a sensor central point, if the optical axis of the optical system of the camera is extended toward the photoelectric conversion device in a straight line, the sensor central point being a point where the extended optical axis reaches the photoelectric conversion device;

acquiring a vertical coordinate of a target-image landing point, if the camera-target connection line is extended toward the photoelectric conversion device in a straight line, the target-image landing point being a point where an extended line reaches the photoelectric conversion device;

acquiring an image vertical distance, which is a vertical distance between the sensor central point and the target-image landing point; and

acquiring a quotient of the image vertical distance divided by a focal distance of the optical system, and setting an arctangent value of the quotient as the camera-target angle.

10. A camera for acquiring a horizontal distance between the camera and a target, which is a horizontal distance between a central point of an optical system of the camera and a ground landing point,

wherein the camera is configured to acquire a relative target angle using an angle between ground and a camera-target connection line which connects the central point of the optical system of the camera and the ground landing point of the target,

wherein the camera is further configured to acquire a height of the camera using a height of the central point of the optical system of the camera on a basis of a vertical position of the ground landing point of the target, and

wherein the camera is further configured to set a quotient of the height of the camera divided by a tangent value of the relative target angle as a horizontal distance between the camera and the target.

11. A surveillance system comprising:

a camera connected to a host device, the host device acquiring a horizontal distance between the camera and a target which is a horizontal distance between a central point of an optical system of the camera and a ground landing point of the target,

wherein the host device is configured to acquire a relative target angle which is an angle between ground and a camera-target connection line which connects the central point of the optical system of the camera and the ground landing point of the target,

wherein the host device is further configured to acquire a height of the camera which is a height of the central point of the optical system of the camera on a basis of a vertical position of the ground landing point of the target, and

wherein the host device is further configured to set a quotient of the height of the camera divided by a tangent value of the relative target angle as the horizontal distance between the camera and the target.