A full coverage capture method within the visual range of a camera, an electronic device and a storage medium

Abstract

The present invention relates to a method, electronic device, and storage medium for capturing full coverage within the visual range of a camera. The method divides the monitoring range into different visual range bands and sets different focal lengths for each visual range band to obtain the horizontal field of view angles corresponding to the different visual range bands. The shooting frequency of each visual range band is obtained based on the shooting time and horizontal field of view angle set by the camera, thereby obtaining the minimum number of photos required to capture each visual range band. The method for capturing full coverage within the visual range of the camera of the present invention minimizes the amount of captured data while ensuring that each divided visual range band is fully captured, thereby avoiding large amounts of overwritten data. This reduces the device's requirements for memory and computing power, and has a wider range of applicability.

Description

Technical Field

[0001] The present invention relates to the field of camera cruise technology, and in particular to a full-coverage capture method within the visual range of a camera, an electronic device, and a storage medium. Background Art

[0002] In the field of natural resource monitoring, image measurement, machine vision and other technologies are usually used to achieve dynamic monitoring of natural resources. When using image measurement, a pan-tilt camera is usually set up at a certain monitoring point. The pan-tilt camera is set up at a height of 20 meters to 50 meters above the ground. Within the visual range of the pan-tilt camera, image monitoring within a range of several kilometers is achieved. Figure 1 The solid line in the figure is the visual range of the PTZ camera.

[0003] When the PTZ camera performs 360° snapshot monitoring of the situation around the monitoring point within the visual range, Figure 2 As shown, the PTZ camera takes itself as the center of the circle and divides its visual range into several annular strips to monitor objects within the visual range, so that each annular strip corresponds to a pitch angle T and a magnification Z. Then, according to the fixed shooting frequency set at the fixed rotation speed of the PTZ camera, the horizontal rotation angle P of each annular strip is changed to capture the image, or cruise capture based on the preset points configured in each annular strip is performed.

[0004] When taking snapshots at a fixed shooting frequency, the following problems arise:

[0005] 1) When capturing an annular strip near the center of a circle, there is a high degree of overlap between images, which leads to data redundancy and increases the workload and difficulty of subsequent image stitching.

[0006] 2) When capturing circular strips close to the boundary of the visible range, it is easy to miss photos, resulting in the omission of illegal construction, destruction of cultivated land and other natural resource violations.

[0007] When using preset points to take snapshots, there is also the problem of missing shots.

[0008] The above methods are unable to take into account both the amount of shooting data and the problem of avoiding missed shots. Summary of the Invention

[0009] Based on this, the object of the present invention is to provide a full coverage capture method within the visual range of a camera.

[0010] A method for capturing full coverage within the visual range of a camera, comprising the following steps:

[0011] S10: Find the i-th focal length f corresponding to the i-th visual range band of the camera from the attitude parameter matrix Λi , according to the i-th focal length f i Calculate the i-th horizontal field of view angle Hfov i ;

[0012] S20: According to the i-th horizontal field of view Hfov i Calculate the shooting frequency ν of the camera in the i-th visual range i , where the shooting frequency ν i satisfy:

[0013] ν i =t / [360° / Hfov i ]

[0014] Where: t represents the time for the camera to rotate 360° horizontally, [] represents the rounding function;

[0015] S30: Control the focal length of the camera to be the i-th focal length f i , with shooting frequency ν i Monitor and capture the i-th visual range.

[0016] Furthermore, the step S30 further includes:

[0017] Find the i-th zoom factor Z corresponding to the i-th visual range band of the camera from the attitude parameter matrix Λ i When controlling the camera to monitor and capture the i-th visual range, it is also necessary to control the camera's zoom ratio to be the i-th zoom ratio Z i .

[0018] Furthermore, the i-th horizontal field of view Hfov i satisfy:

[0019]

[0020] Where: w represents the width of the camera sensor size.

[0021] Furthermore, the attitude parameter matrix Λ is obtained by the following method:

[0022] SA1: Get the i-th pitch angle T of the camera i , and based on the pitch angle T i Determine the i-th focal length f corresponding to the i-th visual range band i and the i-th magnification Z i , where the i-th focal length f i and the i-th magnification Z i Enable the camera to clearly capture ground objects within the i-th visual range;

[0023] SA2: According to the i-th focal length f iCalculate the vertical field of view angle Vfov of the camera i i , according to the i-th pitch angle T i , the i-th vertical field of view Vfov i Get the angle range of the i-th visual range (θ i-min ,θ i-max ), the angle of the i-th visual range band is the angle with the camera height axis;

[0024] SA3: Adjust the camera's pitch angle to the (i+1)th pitch angle T i+1 , so that the minimum viewing angle θ of the i+1th visible range is i+1-min The maximum viewing angle θ of the i-th visual range band i-max Equal, and then determine the i+1th visible range band (R i-max ,R i+1-max ) and its corresponding i+1th focal length f i+1 、i+1th magnification Z i+1 ; And so on, according to the pitch angle, visual range, focal length, and zoom ratio, the attitude parameter matrix Λ of the entire monitoring range of the camera is obtained:

[0025]

[0026] Furthermore, the step SA1 includes the following sub-steps:

[0027] SA11: Get the i-th pitch angle T of the camera i , and obtain the camera's pitch angle T i The image height h′ of a target object in the center of the image captured at 目标 and position information, where the image height h′ 目标 is the height of the target object in the captured image;

[0028] SA12: Obtaining the height h of the target object in the elevation data based on the position information of the target object 目标 ;

[0029] SA13: Get the camera height H, combined with the i-th pitch angle T i Calculate the object distance u from the target object to the camera i , object distance u i satisfy:

[0030] u i =H / cos(90°-T i );

[0031] SA14: Based on the image height h′ of the target object 目标 、Height h 目标 , object distance u i Calculate the image distance vi , image distance v i satisfy:

[0032]

[0033] SA15: According to the object distance u i and image distance v i Calculate the i-th focal length f i , i-th magnification Z i , the i-th focal length f i satisfy:

[0034]

[0035] The i-th magnification ratio Z i satisfy:

[0036]

[0037] Furthermore, the step SA1 includes the following sub-steps:

[0038] SA11: Get the i-th pitch angle T of the camera i , and obtain the camera's pitch angle T i The image height h′ of a target object in the center of the image captured at 目标 and position information, where the image height h′ 目标 is the height of the target object in the captured image;

[0039] SA12: Obtaining the height h of the target object in the elevation data based on the position information of the target object 目标 ;

[0040] SA13: Get the camera height H, combined with the i-th pitch angle T i Calculate the object distance u from the target object to the camera i , object distance u i satisfy:

[0041] u i =H / cos(90°-T i );

[0042] SA14: Based on the image height h′ of the target object 目标 、Height h 目标 , object distance u i Calculate the image distance v i , image distance v i satisfy:

[0043]

[0044] SA15: According to the object distance ui and image distance v i Calculate the i-th focal length f i , the i-th focal length f i satisfy:

[0045]

[0046] SA16: Get the wide-angle focal length f of the camera 广角 , according to the wide-angle focal length f 广角 and the i-th focal length f i Calculate the i-th magnification Z i , the i-th magnification Z i satisfy:

[0047]

[0048] Furthermore, the step SA2 includes the following sub-steps:

[0049] SA21: According to the i-th focal length f i Calculate the vertical field of view angle Vfov of the camera i i , the i-th vertical field of view Vfov i satisfy:

[0050]

[0051] Where h is the height parameter in the camera sensor size;

[0052] SA22: According to the i-th pitch angle T i , the i-th vertical field of view Vfov i Calculate the maximum viewing angle θ of the i-th visual range band i-max and the minimum field of view angle θ i-min , get the angle range of the i-th visual range (θ i-min ,θ i-max ):

[0053] θ i-min =90-T i -Vfov22;

[0054] θ i-max =90-T i +Vfov i 2;

[0055] SA23: According to the camera height H, the i-th visual range angle range (θ i-min ,θ i-max ), calculate the i-th visible range band (R i-min ,R i-max ), the i-th visual range band is the radius from the projection point of the camera on the ground, where

[0056] R i-min =H*tan(θ i-min );

[0057] R i-max =H*tan(θ 1-max ).

[0058] Furthermore, the attitude parameter matrix Λ is obtained by the following method:

[0059] SA`1: According to the camera height H, the monitoring range is divided into several visual range bands R with the camera's projection point on the ground as the center. i ; Determine each visual range with R i The corresponding pitch angle T i , i∈(1,n);

[0060] SA`2: Adjust the viewing range with R according to the maximum and minimum zoom ratio of the camera i The segmented proportional zoom ratio is rounded to get the visual range of R i Corresponding magnification Z i ;

[0061] SA`3: R according to each visual range i Corresponding magnification Z i Calculate each visible range band R i The corresponding focal length f i , f i satisfy:

[0062] f i =kZ i

[0063] Where k represents the slope of the linear relationship;

[0064] SA`4: R according to each visual range i and its corresponding pitch angle T i , zoom ratio Z i and focal length f i , obtain the attitude parameter matrix Λ of the entire monitoring range of the camera:

[0065]

[0066] Compared to the existing technology, the present invention divides the monitoring range into different visual range bands and sets different focal lengths for each visual range band to obtain the horizontal field of view angle corresponding to each visual range band. Based on the shooting time and horizontal field of view angle set by the camera, the shooting frequency of each visual range band is determined, thereby obtaining the minimum number of photos required to capture each visual range band. The present invention's method for capturing full coverage within the camera's visual range minimizes the amount of captured data while ensuring full coverage of each divided visual range band, eliminating the occurrence of large amounts of overwritten data. This reduces the device's requirements for memory and computing power, and has a wider range of applicability.

[0067] For better understanding and implementation, the present invention is described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 A schematic diagram of an existing PTZ camera performing video recording within a visual range;

[0069] Figure 2 for Figure 1 Schematic diagram of the corresponding existing pan-tilt camera dividing the visual range into several annular strips for recording;

[0070] Figure 3 Flowchart of the full coverage capture method of the camera of the present invention;

[0071] Figure 4 Schematic diagram of the number of snapshots in the first visual range and the second visual range according to an embodiment of the present invention. DETAILED DESCRIPTION

[0072] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the present invention.

[0073] To address the problem that existing camera and snapshot cruise control methods cannot simultaneously reduce data volume and avoid missed shots during camera monitoring, the present invention proposes a method for capturing full coverage within the camera's visual range. This method divides the monitoring range into different visual range bands and sets different focal lengths for each visual range band to obtain the horizontal field of view angle corresponding to the different visual range bands. Based on the shooting time and horizontal field of view angle set by the camera, the shooting frequency of each visual range band is obtained to obtain the minimum number of photos required to be captured for each visual range band. The present invention's method for capturing full coverage within the camera's visual range minimizes the amount of captured data while ensuring that each divided visual range band is fully captured, avoiding large amounts of overwritten data, reducing the device's requirements for memory and computing power, and having a wider range of applicability.

[0074] See also Figure 3The present invention proposes a full coverage capture method within the visual range of a camera, which includes the following steps.

[0075] S10: Find the i-th focal length f corresponding to the i-th visual range band of the camera from the attitude parameter matrix Λ i , according to the i-th focal length f i Calculate the i-th horizontal field of view angle Hfov i , where the i-th horizontal field of view Hfov i satisfy:

[0076]

[0077] Where: w represents the width of the camera sensor size.

[0078] S20: According to the i-th horizontal field of view Hfov i Calculate the shooting frequency ν of the camera in the i-th visual range i , where the shooting frequency ν i satisfy:

[0079] ν i =t / [360° / Hfov i ]

[0080] Where: t represents the time it takes for the camera to rotate 360° horizontally, and [] represents the rounding function.

[0081] S30: Find the i-th zoom factor Z corresponding to the i-th visual range band of the camera from the posture parameter matrix Λ i , control the focal length of the camera to be the i-th focal length f i , the magnification is the i-th magnification Z i , with shooting frequency ν i Monitor and capture the i-th visual range.

[0082] In one embodiment, by shooting the target object, the i-th visual range band of the camera and its corresponding focal length f are calculated. i , zoom ratio Z i , and obtain the attitude parameter matrix Λ. The specific method is as follows.

[0083] SA1: Get the i-th pitch angle T of the camera i , and based on the pitch angle T i Determine the i-th focal length f corresponding to the i-th visual range band i and the i-th magnification Z i , where the i-th focal length f i and the i-th magnification Z i The camera can clearly capture ground objects within the i-th visual range.

[0084] The camera's pitch angle T i When the camera is placed at height H, the angle between the optical axis of the camera and the horizontal plane is the angle between the camera and the horizontal plane. In this case, the pitch angle is a negative value. The first pitch angle T1 of the camera corresponds to the first visual range, which is the closest visual range to the projection point C of the camera on the ground. Similarly, the nth pitch angle T n The corresponding n-th visual range band is the visual range band farthest from the projection point C of the camera on the ground.

[0085] The specific steps include:

[0086] SA11: Get the i-th pitch angle T of the camera i , and obtain the camera's pitch angle T i The image height h′ of a target object in the center of the image captured at 目标 and position information, where the image height h′ 目标 is the height of the target object in the captured image;

[0087] SA12: Obtaining the height h of the target object in the elevation data based on the position information of the target object 目标 ;

[0088] SA13: Get the camera height H, combined with the i-th pitch angle T i Calculate the object distance u from the target object to the camera i , object distance u i satisfy:

[0089] u i =H / cos(90°-T i );

[0090] SA14: Based on the image height h′ of the target object 目标 、Height h 目标 , object distance u i Calculate the image distance v i , image distance v i satisfy:

[0091]

[0092] SA15: According to the object distance u i and image distance v i Calculate the i-th focal length f i , i-th magnification Z i , the i-th focal length f i satisfy:

[0093]

[0094] The i-th magnification ratio Z isatisfy:

[0095]

[0096] Or use the following method to calculate the i-th magnification Z i .

[0097] SA16: Get the wide-angle focal length f of the camera 广角 , according to the wide-angle focal length f 广角 and the i-th focal length f i Calculate the i-th magnification Z i , the i-th magnification Z i satisfy:

[0098]

[0099] SA2: According to the i-th focal length f i Calculate the vertical field of view angle Vfov of the camera i i , according to the i-th pitch angle T i , the i-th vertical field of view Vfov i Get the angle range of the i-th visual range (θ i-min ,θ i-max ), the angle of the i-th visual range band is the angle with the camera height axis.

[0100] The following sub-steps are included:

[0101] SA21: According to the i-th focal length f i Calculate the vertical field of view angle Vfov of the camera i i , the i-th vertical field of view Vfov i satisfy:

[0102]

[0103] Where h is the height parameter in the camera sensor size;

[0104] SA22: According to the i-th pitch angle T i , the i-th vertical field of view Vfov i Calculate the maximum viewing angle θ of the i-th visual range band i-max and the minimum field of view angle θ i-min , get the angle range of the i-th visual range (θ i-min ,θ i-max ):

[0105] θ i-min =90-T i -Vfov22;

[0106] θ i-max =90-T i +Vfovi 2.

[0107] SA23: According to the camera height H, the i-th visual range angle range (θ i-min ,θ i-max ), calculate the i-th visible range band (R i-min ,R i-max ), the i-th visual range band is the radius from the projection point of the camera on the ground, where

[0108] R i-min =H*tan(θ i-min );

[0109] R i-max =H*tan(θ 1-max ).

[0110] SA3: Adjust the camera's pitch angle to the (i+1)th pitch angle T i+1 , so that the minimum viewing angle θ of the i+1th visible range is i+1-min The maximum viewing angle θ of the i-th visual range band i-max Equal, and then determine the i+1th visible range band (R i-max ,R i+1-max ) and its corresponding i+1th focal length f i+1 、i+1th magnification Z i+1 ; And so on, according to the pitch angle, visual range, focal length, and zoom ratio, the attitude parameter matrix Λ of the entire monitoring range of the camera is obtained:

[0111]

[0112] In another embodiment, the camera lens has a digital zoom function, and the monitoring range corresponding to such a camera is pre-set to obtain the camera's posture parameter matrix Λ, including the following steps.

[0113] SA`1: According to the camera height H, the monitoring range is divided into several visual range bands R with the camera's projection point on the ground as the center. i ; Determine the pitch angle T corresponding to each visual range band i , i∈(1,n);

[0114] Furthermore, the visual range is R i Set to equal spacing.

[0115] SA`2: Adjust the viewing range with R according to the maximum and minimum zoom ratio of the camera i The segmented proportional zoom ratio is rounded to get the visual range of R i Corresponding magnification Z i .

[0116] SA`3: R according to each visual range i Corresponding magnification Z i Calculate each visible range band R i The corresponding focal length f i , f i satisfy:

[0117] f i =kZ i

[0118] Where k represents the slope of the linear relationship.

[0119] SA`4: R according to each visual range i and its corresponding pitch angle T i , zoom ratio Z i and focal length f i , obtain the attitude parameter matrix Λ of the entire monitoring range of the camera:

[0120]

[0121] Example 1: A 1 / 1.8" Progressive Scan CMOS digital zoom camera at a height of 35m, with a sensor width of 7.2mm and a zoom ratio of Z. i 0~40, the time of one rotation is 10 minutes, and the monitoring range of 1500m is divided into 6 visible range bands with radius of 200m, 500m, 800m, 1000m, 1200m and 1500m respectively. Its attitude parameter matrix Λ is expressed as:

[0122]

[0123] According to the above-mentioned attitude parameter matrix Λ, the capture frequency and number of captured photos in different visual ranges are obtained, as shown in Table 1.

[0124] Table 1

[0125]

[0126] According to Table 1, in the first visual range, the camera only needs to take a photo every 100 seconds, and a total of six photos are needed to fully cover the first visual range with high-definition snapshot monitoring; in the sixth visual range, the camera needs to take a photo every 3.2 seconds, and a total of 190 photos are needed to fully cover the sixth visual range with high-definition snapshot monitoring.

[0127] It can be seen from this that the full-coverage capture method within the visible range of the camera proposed in the present invention requires different magnifications and focal lengths to be set according to different visible range bands, and requires different shooting frequencies, so as to reduce the amount of data as much as possible on the basis of achieving full-coverage high-definition capture monitoring, avoid large amounts of coverage data, reduce the device's requirements for memory and computing power, and have a wider range of applicability.

[0128] The above-mentioned method for capturing full coverage within the visual range of the camera is stored in an electronic device, and the steps of realizing capturing full coverage within the visual range of the camera are executed by the electronic device.

[0129] The electronic device includes but is not limited to a memory, a processor, and a network interface that can be communicatively connected to each other via a system bus.

[0130] The electronic device may be a computing device such as a rack server, a blade server, a tower server or a cabinet server.

[0131] The memory includes at least one type of readable storage medium, including flash memory, hard disk, multimedia card, card-type memory (e.g., SD or DX memory), random access memory (RAM), static random access memory (SRAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), programmable read-only memory (PROM), magnetic memory, magnetic disk, optical disk, etc. The memory can be an internal storage unit of the electronic device, such as the hard disk or memory of the electronic device; the memory can also be an external storage device of the electronic device, such as a plug-in hard disk equipped on the electronic device, a smart memory card (SMC), a secure digital (SD) card, a flash card, etc.

[0132] The processor can be a central processing unit (CPU), a controller, a microcontroller, a microprocessor, or other data processing chip. The processor is generally used to control the overall operation of the electronic device, such as performing control and processing related to data interaction or communication with the electronic device. The processor is used to run the program code stored in the memory or process data, such as running the full coverage capture method within the visual range of the camera.

[0133] The network interface may include a wireless network interface or a wired network interface, which is generally used to establish a communication connection between the electronic device and other electronic devices. For example, the network interface is used to connect the electronic device to an external data platform via a network, and to establish a data transmission channel and a communication connection between the electronic device and the external data platform. The network may be a wireless or wired network such as an intranet, the Internet, a global system of mobile communications (GSM), wideband code division multiple access (WCDMA), a 4G network, a 5G network, Bluetooth, or Wi-Fi.

[0134] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the embodiments of the present application. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the claims are also intended to include plural forms, unless the context clearly indicates other meanings. It should also be understood that, unless otherwise specified, "multiple" and "several" refer to two or more; "and / or" refers to and includes any or all possible combinations of one or more associated listed items; "first", "second", "third" and the like are only used to distinguish, and are not used to describe a specific order or sequence, nor can they be understood as indicating or implying relative importance. When the above description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. In the description of the present application, for those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to the specific circumstances.

[0135] The above-described embodiments merely represent several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous modifications and improvements without departing from the spirit of the present invention, and the present invention is intended to encompass such modifications and variations.

Claims

1. A method for capturing full coverage within the visual range of a camera, characterized in that: The following steps are involved: S10: Find the i-th focal length f corresponding to the i-th visual range band of the camera from the attitude parameter matrix Λ i , according to the i-th focal length f i Calculate the i-th horizontal field of view angle Hfov i ; S20: According to the i-th horizontal field of view Hfov i Calculate the shooting frequency ν of the camera in the i-th visual range i , where the shooting frequency ν i satisfy: ν i =t / [360° / Hfov i ] Where: t represents the time for the camera to rotate 360° horizontally, [] represents the rounding function; S30: Control the focal length of the camera to be the i-th focal length f i , with shooting frequency ν i Monitor and capture the i-th visual range; Among them, the attitude parameter matrix Λ is obtained by the following method: SA`1: According to the camera height H, the monitoring range is divided into several visual range bands R with the camera's projection point on the ground as the center. i ; Determine the pitch angle T corresponding to each visual range band i , i∈(1,n); SA`2: Adjust the viewing range with R according to the maximum and minimum zoom ratio of the camera i The segmented proportional zoom ratio is rounded to get the visual range of R i Corresponding magnification Z i ; SA`3: R according to each visual range i Corresponding magnification Z i Calculate each visible range band R i The corresponding focal length f i , f i satisfy: f i =kZ i Where k represents the slope of the linear relationship; SA`4: R according to each visual range i and its corresponding pitch angle T i , zoom ratio Z i and focal length f i , obtain the attitude parameter matrix Λ of the entire monitoring range of the camera:

2. The method for capturing full coverage within the visual range of a camera according to claim 1, characterized in that: The step S30 further includes: Find the i-th zoom factor Z corresponding to the i-th visual range band of the camera from the attitude parameter matrix Λ i When controlling the camera to monitor and capture the i-th visual range, it is also necessary to control the camera's zoom ratio to be the i-th zoom ratio Z i .

3. The method for capturing full coverage within the visual range of a camera according to claim 2, characterized in that: The i-th horizontal field of view Hfov i satisfy: Where: w represents the width of the camera sensor size.

4. An electronic device, characterized in that: include: one or more processors; A memory for storing one or more programs, which, when executed by the one or more processors, enables the one or more processors to implement the full-coverage capture method within the visible range of the camera as described in any one of claims 1-3.

5. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for capturing full coverage within the visual range of a camera as described in any one of claims 1 to 3 is implemented.

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