CN115442531A - Method for determining direction of camera and camera direction determining device - Google Patents

Abstract

The invention provides a method for determining the direction of the camera, which includes determining the shooting range of the camera, selecting a reference object within the shooting range, and obtaining the latitude and longitude or coordinates of the camera and the reference object; controlling the rotation of the camera until the reference object is horizontally centered in the viewfinder frame of the camera , and then determine the rotation angle of the camera during the rotation process; determine the offset reference angle of the camera according to the latitude and longitude or coordinates of the camera and the reference object, and the preset geographic reference direction; determine the offset of the camera according to the offset reference angle and the rotation angle Quantity; determine the geographical direction of the camera according to the offset and rotation angle. The invention can accurately determine the direction of the camera without adding additional hardware, and can avoid measurement errors caused by other factors such as geomagnetic interference while reducing costs.

Description

A method for determining the direction of the camera and a device for determining the direction of the camera

technical field

The present application relates to the technical field of positioning, and in particular to a method for determining the direction of a camera and a device for determining the direction of the camera.

Background technique

With the development of the security monitoring industry, people have higher requirements for the positioning accuracy of monitoring targets. There are usually two existing methods for determining the direction of the camera: specify or measure and record the direction of the camera during installation, and then convert the angle of the camera into a geographic direction; add sensors such as an electronic compass to identify the direction of the camera.

However, the method of specifying or measuring and recording the direction of the camera during installation requires time-consuming adjustment and measurement, increases the workload of installation, and has low accuracy. On the other hand, adding sensors such as an electronic compass to identify the direction of the camera requires additional hardware and increases costs. Moreover, the electronic compass needs to be calibrated, and the calibration method usually needs to move the sensor in different directions, which is difficult for fixed devices such as cameras with large volume and weight. In addition, the accuracy of the electronic compass is also easily affected by temperature. Both of the above methods rely on magnetic fields to determine geographic directions, and magnetic fields are easily disturbed by uncertain factors such as metals and electric currents.

Contents of the invention

In view of this, the present invention provides a method for determining the direction of the camera and a device for determining the direction of the camera, which are used to solve the defects in the existing methods for determining the direction of the camera.

In order to achieve the above object, the application adopts the following technical solutions:

Determine the shooting range of the camera, select a reference object within the shooting range, and obtain the latitude and longitude or coordinates of the camera and the reference object;

controlling the rotation of the camera until the reference object is horizontally centered within the viewfinder frame of the camera, and then determining the rotation angle of the camera during rotation;

determining the offset reference angle of the camera according to the latitude and longitude or coordinates of the camera and the reference object, and a preset geographic reference direction;

determining the offset of the camera according to the offset reference angle and the rotation angle;

Determine the geographic direction of the camera according to the offset and the rotation angle.

In an embodiment, the offset reference angle is an angle formed by a line connecting the camera and the reference object and the geographic reference direction.

In one embodiment, the rotation angle is an angle formed by the current shooting direction of the camera and a line connecting the camera and the reference object.

In one embodiment, the determining the offset of the camera according to the offset reference angle and the rotation angle includes:

converting the rotation angle to be in the same coordinate system as the offset reference angle;

The difference between the offset reference angle and the rotation angle in the same coordinate system is used as the offset.

In one embodiment, the determining the geographic direction of the camera according to the offset and the rotation angle includes:

Controlling the rotation of the camera again until the target object is horizontally centered in the viewfinder frame of the camera, and then determining the rotation angle of the camera during rotation;

The sum of the offset and the rotation angle is used as the geographic direction of the camera.

In one embodiment, the determining the shooting range of the camera includes:

determining a first radius according to the installation height and inclination of the camera, and determining a first area according to the first radius;

determining a second radius according to the installation height, inclination and vertical viewing angle of the camera, and determining a second area according to the second radius;

The difference between the second area and the first area is used as the shooting range.

In one embodiment, the method also includes:

setting the camera on the first light pole;

The second light pole within the shooting range is used as the reference object.

In one embodiment, the method also includes:

setting the camera on the first light pole;

The lamps installed on the second light pole within the shooting range are used as the reference object;

Control the light fixture to flicker.

A device for determining the direction of a camera, comprising:

The shooting parameter determination module is used to determine the shooting range of the camera, select a reference object within the shooting range, and obtain the latitude and longitude or coordinates of the camera and the reference object;

A rotation control module, configured to control the rotation of the camera until the reference object is horizontally centered in the viewfinder frame of the camera, and then determine the rotation angle of the camera during rotation;

A reference angle determination module, configured to determine the offset reference angle of the camera according to the latitude and longitude or coordinates of the camera and the reference object, and a preset geographic reference direction;

An offset determining module, configured to determine the offset of the camera according to the offset reference angle and the rotation angle;

A direction determining module, configured to determine the geographical direction of the camera according to the offset and the rotation angle.

In one embodiment, the device for determining the direction of the camera further includes a first light pole and a second light pole, the first light pole is used for installing the camera, and the second light pole is arranged on the Within the scope, it is used to serve as the reference object or install the reference object.

The invention can accurately determine the direction of the camera without adding additional hardware, and can avoid measurement errors caused by other factors such as geomagnetic interference while reducing costs.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the accompanying drawings used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, so It should be regarded as a limitation on the scope, and those skilled in the art can also obtain other related drawings based on these drawings without creative work.

FIG. 1 is a schematic flow diagram of determining the direction of a camera provided by an embodiment of the present application;

FIG. 2 is a schematic diagram of determining the geographic direction of a camera provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of determining the shooting range of a camera provided by an embodiment of the present application;

FIG. 4 is a schematic diagram of determining a shooting range of a camera provided by another embodiment of the present application.

detailed description

Specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Apparently, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the description of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

In the description of the present invention, unless otherwise specified and limited, the terms "installation", "installation", "connection" and so on should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrated Ground connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary. Those of ordinary skill in the art can understand the specific meanings of the above terms in specific situations.

The orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer" etc. is based on the attached The orientation or positional relationship shown in the figure, or the conventional orientation or positional relationship of the invention product in use, is only for the convenience of description and simplification of the description, not to indicate or imply that the referred device or element must have a specific orientation , constructed and operated in a particular orientation and therefore should not be construed as limiting the invention.

Also, the terms "first", "second", "third", etc. are only used to distinguish elements of similar nature, and do not indicate or imply relative importance or a specific order.

Furthermore, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion of elements other than those listed and also other elements not expressly listed.

Please refer to Figure 1, a method for determining the direction of a camera includes the following steps:

S100. Determine the shooting range of the camera, select a reference object within the shooting range, and obtain the latitude and longitude or coordinates of the camera and the reference object.

Specifically, the selected reference object may be any stationary object within the shooting range, such as a tree trunk, an outdoor air conditioner on a building, a street sign, and the like. The latitude and longitude or coordinates of the camera are parameters that have been determined during installation. After the reference object is confirmed, the longitude, latitude or coordinates of the reference object can be obtained through the background network. Camera (CAMERA or WEBCAM), also known as computer camera, computer eye, electronic eye, etc., is a video input device that is widely used in video conferencing, telemedicine and real-time monitoring. In optical instruments, the angle formed by the lens of the optical instrument as the vertex and the two edges of the maximum range where the object image of the measured object can pass through the lens is called the field of view. The size of the field of view determines the field of view of the optical instrument. The larger the field of view, the larger the field of view and the smaller the optical magnification. In layman's terms, if the target object exceeds this angle, it will not be collected in the lens.

S110. Control the rotation of the camera until the reference object is horizontally centered in the frame of the camera, and then determine the rotation angle of the camera during the rotation.

Specifically, the remote interconnection between the camera and the background is realized through the Internet such as 4G/5G. The staff can remotely monitor the working condition of the camera, the content of the shooting and other information in real time in the background, and can control the camera to rotate in any direction. The viewing angle of the camera also includes a horizontal viewing angle and a vertical viewing angle. In the present invention, the shooting range is only related to the vertical viewing angle of the camera, and the background only needs to rotate the camera horizontally. The reference object is centered horizontally within the camera’s viewfinder frame, which is equivalent to the reference object being centered in the vertical field of view direction of the camera. The rotation angle of the camera is the angle formed by the direction in which the camera's current viewfinder is centered and the direction in which the camera rotates to the reference object. This method does not need to rotate the camera in the vertical direction, which simplifies the steps of obtaining the geographic direction of the camera.

S120. Determine an offset reference angle of the camera according to the latitude and longitude or coordinates of the camera and the reference object, and a preset geographic reference direction.

Specifically, according to the latitude and longitude or coordinates of the camera and the reference object obtained in step S100, the camera and the reference object are arranged in the form of points on the two-dimensional coordinate system, with the position of the camera as the origin, and the preset geographic reference direction is the polar axis, and the position relationship diagram between the camera and the reference object on the two-dimensional coordinate system can be obtained. Wherein, the preset geographic reference direction can be artificially specified, for example, it can be true north, true south, true east or true west. Connect the coordinate point of the camera and the coordinate point of the reference object into a line segment, and the angle formed between the line segment and the polar axis is the offset reference angle.

S130. Determine the offset of the camera according to the offset reference angle and the rotation angle.

Specifically, the offset is a fixed value, and by acquiring the offset once, the current geographic direction can be accurately acquired during subsequent use of the camera. Wherein, the rotation angle acquired in step S110 is placed in the two-dimensional coordinate system of the offset reference angle acquired in step S120, and the angle difference between the offset reference angle and the rotation angle is used as the offset of the camera.

S140. Determine the geographic direction of the camera according to the offset and the rotation angle.

Specifically, during actual use of the camera, the geographic direction of the camera may be determined according to its own rotation angle and the offset acquired in step S130.

Please refer to FIG. 2 , in this embodiment, the offset reference angle is the angle formed by the line connecting the camera and the reference object and the geographic reference direction. Establish a two-dimensional coordinate system, take the camera position O as the origin, and the true north direction as the preset geographic reference direction, make a ray along the true north direction N, and use this ray as the polar axis ON in the two-dimensional coordinate system. The initial orientation of the camera is A1, and the position of the reference object is B. The line connecting the camera and the reference object is OB, and the offset reference angle is the angle α1 formed by the line connecting the camera and the reference object being OB and ON.

In this embodiment, the rotation angle is the angle formed by the current shooting direction of the camera and the line connecting the camera and the reference object. Wherein, the rotation angle is the angle α2 formed by OA1 and OB.

In this embodiment, determining the offset of the camera according to the offset reference angle and the rotation angle includes: converting the rotation angle to be in the same coordinate system as the offset reference angle. Among them, in order to more accurately determine the angle when the camera rotates, the range of the rotation angle of the camera is defined as 0000-3600, and the rotation angle obtained by the measurement is divided by 10 so that the rotation angle is converted to the same value as the offset reference angle. in the coordinate system. For example, the measured rotation angles of the camera are 0101, 1036, and 0033, and then converted to the same coordinate system as the offset reference angle to obtain the rotation angles of 10.1°, 103.6°, and 3.3°, respectively.

Take the difference between the offset reference angle and the rotation angle in the same coordinate system as the offset. Among them, α2 is the converted rotation angle. Subtract the angles α1 and α2, and the difference obtained is used as the offset of the camera, that is, in this embodiment, β is the offset of the camera, which can also be called an offset angle.

In this embodiment, the geographic direction of the camera is determined according to the offset and rotation angle, including:

Control the rotation of the camera again until the target object is horizontally centered in the viewfinder frame of the camera, and then determine the rotation angle of the camera during rotation. Wherein, it is assumed that the direction of the camera is rotated from A1 to A2, and the rotation angle is converted to α3.

The sum of the offset and the rotation angle is used as the geographic direction of the camera. Wherein, the geographic direction of the camera is the sum of the offset β and the rotation angle α3, that is, ∠A2ON. For example, if the offset β is 15°, and the rotation angle α3 of the camera is 270°, then the angle formed by the camera relative to the preset geographic reference direction is 270°+15°=285°, that is, the geographic direction of the camera at this time is 285° northwest.

Please refer to FIG. 3. In one embodiment, determining the shooting range of the camera includes:

The first radius r1 is determined according to the installation height H and the inclination angle θ1 of the camera, and the first area is determined according to the first radius r1. Wherein, the inclination angle θ1 is the angle formed by the lens of the camera and the installation height H. The first radius r1 is the distance formed by the inclination angle θ1 on the horizontal ground, and the first area can be obtained according to the first radius r1 as Πr1.

The second radius r2 is determined according to the installation height H of the camera, the inclination angle θ1 and the vertical viewing angle θ2, and the second area is determined according to the second radius r2. Among them, the vertical viewing angle θ2 is the angular size of the vertical viewing angle of the camera factory. The second radius r2 is the sum of the inclination angle θ1 and the vertical viewing angle θ2, and the distance formed on the horizontal ground. According to the second radius r2, the second area can be obtained as Πr2.

The difference between the second area and the first area is taken as the shooting range. In one embodiment, the shooting range of the camera is a ring-shaped area (Πr2-Πr1), and the reference object may be any stationary object within the ring-shaped area.

Please refer to FIG. 4 , in this embodiment, the camera is set on the first light pole, and the second light pole within the shooting range is used as a reference object. Wherein, at this time, the inclination angle θ1 of the camera is relatively large, and the shooting range of the camera is based on the vertical viewing angle θ2. The second light pole is another light pole adjacent to the first light pole within the range of the vertical viewing angle θ2.

In this embodiment, the lamp K is set on the second lamp post within the shooting range as a reference object, and the lamp K is controlled to flash through the background. Among them, since the latitude and longitude or coordinates of all light poles are known when they are installed, it is relatively preferable to use the second light pole within the shooting range of the camera as the reference object when selecting the reference object. On the other hand, due to the height limitation of the second light pole, in this embodiment, the reference object is further limited to the fixed lamp K on the second light pole. When the actual measurement is a night environment, the lamp K can be controlled to flicker through the background, so that the camera can more accurately capture the reference object, thereby obtaining a more accurate geographic direction.

The present invention also provides a device for determining the direction of the camera, including a shooting parameter determination module for determining the shooting range of the camera, selecting a reference object within the shooting range, and obtaining the latitude and longitude or coordinates of the camera and the reference object, and controlling the rotation of the camera. , until the reference object is horizontally centered in the viewfinder frame of the camera, and then determine the rotation angle of the camera during rotation. A reference angle determination module for the offset reference angle, an offset determination module for determining the offset of the camera according to the offset reference angle and the rotation angle, and a direction determination for determining the geographic direction of the camera according to the offset and the rotation angle module.

In this embodiment, the device for determining the direction of the camera further includes a first light pole and a second light pole, the first light pole is used to install the camera, and the second light pole is set within the shooting range to serve as a reference object or Set up the reference object. For the application examples of the first light pole and the second light pole, please refer to the above description.

The above is only a specific embodiment of the present application, but the protection scope of the present application is not limited thereto. Any person familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present invention. All should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the appended claims.

Claims (10)

1. A method of determining camera orientation, comprising:

determining a shooting range of a camera, selecting a reference object in the shooting range, and acquiring longitude and latitude or coordinates of the camera and the reference object;

controlling the camera to rotate until the reference object is horizontally centered in a viewing frame of the camera, and then determining a rotation angle of the camera in the rotation process;

determining an offset reference angle of the camera according to the latitude and longitude or the coordinates of the camera and the reference object and a preset geographic reference direction;

determining the offset of the camera according to the offset reference angle and the rotation angle;

and determining the geographic direction of the camera according to the offset and the rotation angle.

2. The method of claim 1, wherein the offset reference angle is an angle formed by a line connecting the camera and the reference object and the geographic reference direction.

3. The method according to claim 1, wherein the rotation angle is an included angle formed by a current shooting direction of the camera and a connecting line between the camera and the reference object.

4. The method of claim 1, wherein determining the offset of the camera according to the offset reference angle and the rotation angle comprises:

converting the rotation angle to be in the same coordinate system as the offset reference angle;

and taking the difference value of the offset reference angle and the rotation angle in the same coordinate system as the offset.

5. The method of claim 1, wherein determining the geographic direction of the camera based on the offset and the rotation angle comprises:

controlling the camera to rotate again until a target object is horizontally centered in a viewing frame of the camera, and then determining the rotation angle of the camera in the rotation process;

and taking the sum of the offset and the rotation angle as the geographic direction of the camera.

6. The method of claim 1, wherein the determining a shooting range of a camera comprises:

determining a first radius according to the installation height and the inclination angle of the camera, and determining a first area according to the first radius;

determining a second radius according to the installation height, the inclination angle and the vertical visual angle of the camera, and determining a second area according to the second radius;

and taking the difference between the second area and the first area as the shooting range.

7. The method of claim 1, further comprising:

arranging the camera on a first lamp post;

and taking the second lamp post in the shooting range as the reference object.

8. The method of claim 1, further comprising:

arranging the camera on a first lamp pole;

setting a lamp on a second lamp post in the shooting range as the reference object;

and controlling the lamp to flicker.

9. A camera direction determining apparatus, comprising:

the shooting parameter determining module is used for determining the shooting range of the camera, selecting a reference object in the shooting range and acquiring the longitude and latitude or the coordinates of the camera and the reference object;

the rotation control module is used for controlling the camera to rotate until the reference object is horizontally centered in a viewing frame of the camera, and then determining a rotation angle of the camera in the rotation process;

the reference angle determining module is used for determining an offset reference angle of the camera according to the latitude and longitude or the coordinates of the camera and the reference object and a preset geographic reference direction;

the offset determining module is used for determining the offset of the camera according to the offset reference angle and the rotation angle;

and the direction determining module is used for determining the geographic direction of the camera according to the offset and the rotation angle.

10. The camera direction determining apparatus of claim 9, further comprising a first pole for mounting the camera and a second pole disposed within the shooting range for serving as the reference object or mounting the reference object.

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