Video acquisition method, system and device

Abstract

The embodiment of the invention provides a video acquisition method, system and device, and relates to the technical field of data processing, and the method comprises the steps: receiving the distance and azimuth information between a radar and a first target; if the first target is not in the view field range of the image acquisition equipment, determining rotation angle information enabling the first target to be in the view field range based on the azimuth information; sending rotation angle information to the holder, so that the holder drives the image acquisition equipment to rotate according to the rotation angle information; based on the distance and the size of the interested target, determining a focal length parameter and a focusing parameter which enable the proportion of the first target in the video picture to be a set proportion; and sending the focal length parameter and the focusing parameter to an image acquisition device, so that the image acquisition device performs video acquisition according to the focal length parameter and the focusing parameter. By applying the scheme provided by the embodiment of the invention, the time spent by the image acquisition equipment from focusing to acquisition of the video picture meeting the requirement can be reduced, and the focusing efficiency is improved.

Description

Technical Field

[0001] This application relates to the field of data processing technology, and in particular to a video acquisition method, system and apparatus. Background Technology

[0002] Image acquisition devices can continuously capture video. After receiving the video captured by the image acquisition device, servers and other electronic devices can analyze the targets in the video frame. To improve the accuracy of the electronic devices' analysis of targets in the video frame, it is desirable that the targets in the video frame captured by the image acquisition device are relatively clear and of appropriate size.

[0003] In view of this, in related technologies, after the target enters the field of view of the image acquisition device, the image acquisition device will focus on the target, specifically by changing the focal length and focus value, in an effort to ensure that the video image acquired by the focused image acquisition device meets the requirements in terms of target clarity and size.

[0004] However, the above methods take a long time from focusing to capturing the required video footage, resulting in low efficiency. Summary of the Invention

[0005] The purpose of this application is to provide a video acquisition method, system, and apparatus to reduce the time required for image acquisition devices to go from focusing to acquiring a satisfactory video frame, thereby improving focusing efficiency. The specific technical solution is as follows:

[0006] In a first aspect, embodiments of this application provide a video acquisition method, the method comprising:

[0007] Receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar;

[0008] If the first target is not within the field of view of the image acquisition device, then based on the orientation information, the rotation angle information of the gimbal that would bring the first target within the field of view of the image acquisition device is determined;

[0009] The rotation angle information is sent to the gimbal so that the gimbal drives the image acquisition device to rotate according to the rotation angle information;

[0010] Based on the distance and the first size of the target of interest, a focal length parameter is determined such that the first target occupies a set proportion in the video frame captured by the image acquisition device;

[0011] Based on the distance and focal length parameters, the focusing parameters of the image acquisition device are determined;

[0012] The focal length and focus parameters are sent to the image acquisition device so that the image acquisition device can perform video acquisition according to the focal length and focus parameters.

[0013] Secondly, embodiments of this application provide a video acquisition system, the system comprising: a main control device, a radar, an image acquisition device, and a pan-tilt unit supporting the image acquisition device, wherein...

[0014] The radar is used to detect targets, determine the distance between itself and the detected first target, and the azimuth information of the first target relative to the radar.

[0015] The main control device is configured to, if the first target is not within the field of view of the image acquisition device, determine, based on the orientation information, the rotation angle information of the pan-tilt unit that would place the first target within the field of view of the image acquisition device; send the rotation angle information to the pan-tilt unit; determine, based on the distance and the first size of the target of interest, a focal length parameter that would allow the first target to occupy a set proportion in the video frame captured by the image acquisition device; determine the focusing parameters of the image acquisition device based on the distance and the focal length parameter; and send the focal length parameter and the focusing parameter to the image acquisition device.

[0016] The gimbal is used to drive the image acquisition device to rotate according to the received rotation angle information;

[0017] The image acquisition device is used to acquire video according to the received focal length and focus parameters.

[0018] Thirdly, embodiments of this application provide a video acquisition device, the device comprising:

[0019] An information receiving module is used to receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar.

[0020] The rotation angle information determination module is used to determine the rotation angle information of the pan-tilt unit that makes the first target fall within the field of view of the image acquisition device, based on the orientation information, if the first target is not within the field of view of the image acquisition device.

[0021] A rotation angle information sending module is used to send the rotation angle information to the gimbal so that the gimbal drives the image acquisition device to rotate according to the rotation angle information;

[0022] A focal length parameter determination module is used to determine a focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device, based on the distance and a first size of the target of interest.

[0023] A focus parameter determination module is used to determine the focus parameters of the image acquisition device based on the distance and focal length parameters;

[0024] The parameter sending module is used to send the focal length parameter and focus parameter to the image acquisition device, so that the image acquisition device can perform video acquisition according to the focal length parameter and focus parameter.

[0025] Fourthly, embodiments of this application provide a master control device, including:

[0026] Memory, used to store computer programs;

[0027] A processor, when executing a program stored in memory, implements the method described in the first aspect.

[0028] Fifthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by a processor, implements the method described in the first aspect.

[0029] In a sixth aspect, embodiments of this application also provide a computer program product containing instructions that, when run on a computer, cause the computer to perform the method described in the first aspect.

[0030] As can be seen, in the video acquisition scheme provided in this application embodiment, before the first target enters the field of view of the image acquisition device, the main control device has already obtained the focal length and focus parameters that ensure the first target can be clearly displayed and appropriately sized in the video image captured by the image acquisition device. Thus, the image acquisition device can adjust its focus in advance according to the focal length and focus parameters sent by the main control device. Therefore, after the gimbal rotates the image acquisition device according to the rotation angle information, causing the first target to appear within the field of view of the image acquisition device, the image acquisition device has already completed its focus adjustment and can directly acquire a video image that meets the clarity and size requirements of the target. In other words, the image acquisition device can acquire a video image that meets the requirements as soon as the target appears within its field of view. Therefore, compared to adjusting focus after the target appears within the field of view, the scheme provided in this application embodiment saves the time required for the image acquisition device to adjust focus and acquire a video image that meets the requirements, improving the focusing efficiency of the video acquisition process.

[0031] In addition, the solution provided in this application embodiment enables the image acquisition device to capture a video image that meets the requirements as soon as the target appears in the field of view. Compared with focusing after the target appears in the field of view, the real-time target tracking is stronger, which can reduce the situation where the image acquisition device cannot capture a video image that meets the requirements due to blurring before focusing is completed. This improves the target clarity in the video image captured by the image acquisition device and improves the image quality of the video image.

[0032] Of course, implementing any product or method of this application does not necessarily require achieving all of the advantages described above at the same time. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other embodiments can be obtained based on these drawings.

[0034] Figure 1 A flowchart illustrating the first video acquisition method provided in this application embodiment;

[0035] Figure 2 A flowchart illustrating the second video acquisition method provided in this application embodiment;

[0036] Figure 3 A flowchart illustrating the third video acquisition method provided in this application embodiment;

[0037] Figure 4 A flowchart illustrating the fourth video acquisition method provided in this application embodiment;

[0038] Figure 5a A schematic diagram illustrating a first target pose provided in an embodiment of this application;

[0039] Figure 5b A schematic diagram illustrating a second target pose provided in an embodiment of this application;

[0040] Figure 6 This is a schematic diagram of the structure of a first video acquisition system provided in an embodiment of this application;

[0041] Figure 7 This is a schematic diagram of the structure of a second video acquisition system provided in an embodiment of this application;

[0042] Figure 8 This is a schematic diagram of the structure of a video acquisition device provided in an embodiment of this application;

[0043] Figure 9 This is a schematic diagram of the structure of a master control device provided in an embodiment of this application. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art based on this application are within the scope of protection of this application.

[0045] First, the implementing entity of the solution provided in the embodiments of this application will be described.

[0046] The implementing entity of the solution provided in this application embodiment is any electronic device with data processing, communication, storage, and other functions. In the solution provided in this application embodiment, the aforementioned electronic device can be referred to as the master control device.

[0047] The application scenarios of the solutions provided in the embodiments of this application will be introduced next.

[0048] The application scenario of the solution provided in this application embodiment is: a scene in which an image acquisition device tracks a target of interest, thereby acquiring a video including the target of interest.

[0049] The aforementioned targets of interest can be set according to the actual needs of the application scenario, and this application embodiment does not limit them.

[0050] For example, in a vehicle management scenario, the aforementioned target of interest could be a vehicle; in a street surveillance scenario, the aforementioned target of interest could be a person, etc.

[0051] In related technologies, after the target of interest enters the field of view of the image acquisition device, the device focuses on the target to ensure that the video image captured by the device meets the requirements in terms of target sharpness and size. However, the above method takes a long time from focusing to capturing a satisfactory video image, resulting in low efficiency.

[0052] In view of the above, this application provides a video acquisition scheme to reduce the time required from focusing to acquiring a video frame that meets the requirements, thereby improving focusing efficiency.

[0053] The video acquisition scheme provided in the embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0054] See Figure 1 This is a flowchart illustrating a video acquisition method provided in an embodiment of this application. The method includes the following steps S101-S106.

[0055] Step S101: Receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar.

[0056] The aforementioned radar can be millimeter-wave radar, lidar, ultrasonic radar, or other types of radar. Specifically, the appropriate radar can be selected from the above-mentioned radars based on the distance between the image acquisition device and the target in the actual scenario, the size of the target of interest, etc. This application embodiment does not limit this.

[0057] The radar described above can detect the first target within its field of view at a certain frequency, measure the distance between itself and the first target, and measure the azimuth information of the first target relative to itself, and periodically send the measured distance and azimuth information to the main control equipment.

[0058] The aforementioned azimuth information represents the azimuth of the first target relative to the radar. In one case, the azimuth information may include the azimuth angle and the elevation angle.

[0059] The azimuth angle indicates the position of the target relative to the radar in the horizontal direction. It is the angle between the target on the horizontal plane and the radar reference direction, which is generally due north. The elevation angle indicates the position of the target relative to the radar in the vertical direction. It is the angle between the line connecting the first target and the radar and the horizontal plane.

[0060] After receiving the aforementioned distance and azimuth information sent by the radar, the main control device can execute subsequent steps S102-106 if it determines that the first target is not within the field of view of the image acquisition device.

[0061] The following describes how the main control device determines whether the first target is within the field of view of the image acquisition device.

[0062] In one embodiment, the main control device can determine the target orientation information of the first target relative to the image acquisition device based on the above orientation information and the pre-set relative positional relationship between the radar and the image acquisition device, and then determine whether the first target is within the field of view of the image acquisition device based on the target orientation information.

[0063] The azimuth information obtained by radar measurement represents the azimuth of the first target relative to the radar. Since the relative positional relationship between the radar and the image acquisition device can be known, the azimuth information can be transformed based on the principle of spatial position transformation and the above relative positional relationship to obtain the target azimuth information of the first target relative to the image acquisition device.

[0064] This application does not limit the specific calculation method for performing the above spatial position transformation. The following example introduces a possible implementation method for transforming the above orientation information to obtain the above target orientation information.

[0065] For example, the above azimuth information can be converted into a vector in a coordinate system with the radar position as the origin. Then, based on the above relative positional relationship, the position of the image acquisition device in the above coordinate system can be calculated. The starting point of the vector can be replaced with the above position, and the new vector can represent the azimuth of the first target relative to the image acquisition device. Therefore, the new vector can be used as the above target azimuth information.

[0066] The main control device can store the azimuth range covered by the field of view of the aforementioned image acquisition device. Then, after obtaining the target azimuth information, the main control device can determine whether the azimuth represented by the target azimuth information is within the azimuth range covered by the field of view of the image acquisition device. If yes, it is determined that the first target is within the field of view of the image acquisition device; if no, it is determined that the first target is not within the field of view of the image acquisition device.

[0067] In another implementation, the main control device can receive the target detection results of the captured video image sent by the image acquisition device, and determine whether the first target is within the field of view of the image acquisition device based on the target detection results.

[0068] During the continuous acquisition of video, the image acquisition device can perform target detection on the acquired video footage and send the target detection results to the main control device.

[0069] After receiving the target detection result, if the target detection result indicates that there is no target in the video frame captured by the image acquisition device, it can be determined that there is no target within the field of view of the image acquisition device, and naturally it can also be determined that the first target is not within the field of view of the image acquisition device; if the target detection result indicates that there is a target in the video frame captured by the image acquisition device, it can be determined that the first target is within the field of view of the image acquisition device.

[0070] This embodiment is more applicable to scenarios where targets are sparse within the field of view of the image acquisition device. In such scenarios, at any given time, the field of view of the image acquisition device will often contain only one target. Therefore, if the image acquisition device does not detect a target, it can be assumed that the first target is not within the field of view of the image acquisition device; if the image acquisition device detects a target, it can be assumed that the detected target is the first target, and thus the first target is considered to be within the field of view of the image acquisition device.

[0071] If the first target is not within the field of view of the image acquisition device, proceed with the subsequent steps.

[0072] Step S102: Based on the orientation information, determine the rotation angle information of the pan-tilt unit that makes the first target within the field of view of the image acquisition device.

[0073] The aforementioned gimbal is used to support the image acquisition device and drive the image acquisition device to rotate. For example, the gimbal can rotate smoothly in the horizontal and / or vertical directions, thereby driving the image acquisition device to rotate.

[0074] The following describes the method for determining the aforementioned rotation angle information based on azimuth information.

[0075] As described above, the azimuth information represents the azimuth of the first target relative to the radar. Based on the azimuth information and the pre-set relative positional relationship between the radar and the image acquisition device, the target azimuth information of the first target relative to the image acquisition device can be determined. In this way, based on the target azimuth information and the azimuth interval covered by the field of view of the image acquisition device, the rotation angle information that makes the first target fall within the field of view of the image acquisition device can be determined.

[0076] Similar to the meaning of the aforementioned orientation information, the aforementioned rotation angle information can specifically include the direction angle and the pitch angle, that is, the angle of rotation in the horizontal direction and the angle of rotation in the vertical direction.

[0077] This application does not limit the specific calculation method for determining the above rotation angle information. The following example illustrates a possible implementation method.

[0078] For example, the target orientation information can be converted into a vector in a coordinate system with the position of the image acquisition device as the origin, and the orientation range covered by the field of view can be converted into the coordinate system for representation. Then, the horizontal and vertical offsets required for the second vector to move to the orientation range can be calculated, and the horizontal and vertical offsets can be converted into the azimuth and pitch angles of the image acquisition device as the rotation angle information.

[0079] In one embodiment of this application, when the main control device determines the rotation angle information, it can determine the rotation angle information of the gimbal that makes the first target located in the center area of ​​the field of view of the image acquisition device based on the orientation information.

[0080] For specific implementation details, please refer to the examples above. The only difference is that the azimuth interval covered by the field of view is replaced with the azimuth interval covered by the central region of the field of view. Further details will not be provided here.

[0081] In this way, after the main control device sends the rotation angle information to the pan-tilt unit, the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information, so that the central area of ​​the field of view of the image acquisition device includes the aforementioned first target. In other words, the first target appears in the central area of ​​the video image captured by the image acquisition device, making the first target more obvious and prominent in the video image, which is convenient for subsequent analysis of the target in the video image.

[0082] Step S103: Send rotation angle information to the pan-tilt unit so that the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information.

[0083] After the main control device sends rotation angle information to the pan-tilt unit, the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information, so that the central area of ​​the field of view of the image acquisition device includes the aforementioned first target.

[0084] In one embodiment of this application, the master control device can send PTZ (Pan Tilt Zoom, azimuth angle, pitch angle, focal length) coordinate commands to the gimbal. In the PTZ coordinate command, the P value can be the azimuth angle in the rotation angle information, the T value can be the pitch angle in the rotation angle information, and the Z value can be empty.

[0085] Step S104: Based on the distance and the first size of the target of interest, determine the focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device.

[0086] The aforementioned focal length parameter represents the focal length of the lens set in the image acquisition device. The focal length parameter affects the size of the target in the video frame captured by the image acquisition device.

[0087] In the solution provided in this application embodiment, the image acquisition device can be equipped with a continuously zoom optical lens, that is, the image acquisition device is a device with continuous zoom function. In this way, the image acquisition device can adjust the size of the target in the video frame it captures by adjusting the focal length of the optical lens (this process can also be called zoom).

[0088] In this step, given the distance to the first target and the first size of the target of interest, the main control device can determine the focal length parameters of the image acquisition device, thereby ensuring that when the image acquisition device performs video acquisition according to the determined focal length parameters, the proportion of the first target in the acquired video image can approach the set proportion.

[0089] The aforementioned ratio can be the percentage of pixels of the target in the target direction of the video frame. The target direction can be the horizontal pixel direction (width direction) of the video frame or the vertical pixel direction (height direction) of the video frame. The aforementioned pixel percentage can be set by the staff according to actual needs. Specifically, it can be a fixed ratio, such as 1 / 4, 1 / 2, etc., or it can be a percentage range, such as [1 / 4, 1 / 2], etc. This application embodiment does not limit this.

[0090] The aforementioned focal length parameter is used to indicate the focal length of the image acquisition device. It can be a specific focal length value or a magnification based on the minimum focal length value. The aforementioned magnification can be called a variable magnification value, such as 1.2, 1.4, 1.6, etc.

[0091] The first dimension of the target of interest will be introduced below.

[0092] The first dimension of the target of interest can include the height and width of the target of interest, which can be represented as height × width, and can be divided into the following two cases:

[0093] In the first case, the first dimension is the set dimension.

[0094] Specifically, the main control device can store typical sizes of common targets of interest. The first size can be the typical size of the target of interest to be followed in the current scene.

[0095] The aforementioned common targets of interest may include people, vehicles, boats, drones, etc.; the aforementioned typical dimensions can be set by staff based on experience. For example, the dimensions of a person may be 1.8 × 0.5 meters, the dimensions of a vehicle may be 1.4 × 4.0 meters, and the dimensions of a small boat may be 5 × 10 meters, etc.

[0096] In this case, the set size is used as the first size, which can be understood as the set size being used as the estimated or ideal size of the first target, and the focal length parameter is then calculated based on this estimated size.

[0097] In this way, by pre-setting the first size of the target of interest to be followed in the current scene, the first size can be used as the estimated or ideal size of the first target. Subsequently, based on the first size, the focal length parameter that makes the proportion of the first target in the video frame captured by the image acquisition device approach the set ratio can be calculated, which helps to make the target size in the frame captured by the image acquisition device appropriate.

[0098] In the second case, the first size is the size of the first target as measured by radar.

[0099] In some cases, the aforementioned radar can be a high-resolution radar capable of radar imaging and measuring the target size based on the imaging results. In this case, the size of the first target measured by the radar can be directly used as the first size.

[0100] In this way, the first size is the accurate size of the first target measured by the radar. Subsequently, based on the accurate size, more precise calculations can be made to ensure that the first target occupies a set proportion of the video image captured by the image acquisition device, thereby making the target size in the image captured by the image acquisition device appropriate.

[0101] The specific methods for determining focal length parameters are described below.

[0102] In one embodiment, the focal length parameter that causes the first target to occupy a set proportion in the video frame captured by the image acquisition device can be obtained according to the following expression. :

[0103] ; (1)

[0104] In the above expression (1), num represents the number of pixels occupied by the first target in the target direction of the video screen, calculated based on a set ratio. Specifically, it can be obtained by multiplying the total number of pixels in the target direction of the video screen by the set ratio.

[0105] For example, for an image acquisition device with a CCD (Charge-coupled Device) size of 1 / 1.8 inches and a resolution of 1920×1080 pixels, the total number of pixels in the target direction in the video image it acquires is 1920. If the ratio is set to 1 / 4, then num = 1920 × 1 / 4 = 480.

[0106] In the above expression (1) The pixel size of the image acquisition device can be 3.75 μm (micrometers); D represents the distance between the first target and the radar.

[0107] In the above expression (1), L represents the component of the first dimension of the target of interest in the target direction.

[0108] For example, if the first dimension is W1×L1, it means that the component of the first dimension in the height direction is W1 and the component in the width direction is L1. If the target direction is the width direction, then the above L is L1.

[0109] The above expression allows for convenient and accurate calculation of the focal length parameter that ensures the first target occupies a set proportion in the video frame captured by the image acquisition device.

[0110] In another implementation, the focal length parameters corresponding to the aforementioned distance, first size, and set ratio can be determined based on the pre-built correspondence between target distance, target size, target proportion in video frame, and focal length parameters. This will not be described in detail here.

[0111] Step S105: Determine the focusing parameters of the image acquisition device based on the distance and focal length parameters.

[0112] The aforementioned focusing parameters characterize the distance between the lens and the photosensitive element, and these focusing parameters affect the clarity of the target in the video image captured by the image acquisition device.

[0113] After step S104, the determined focal length parameters enable the proportion of the first target in the video frame captured by the image acquisition device to approach the set proportion. However, the target in the video frame captured by the image acquisition device according to the focal length parameters may not be clear enough. Therefore, it is necessary to further determine the focusing parameters under the determined focal length parameters that can make the target clear, that is, to determine the best clear imaging point of the target.

[0114] Specifically, the focusing parameters of the image acquisition device can be determined in the following ways.

[0115] In one implementation, the main control device can receive the ambient temperature sent by a temperature sensor, and then determine the focusing parameters of the image acquisition device based on the distance, focal length parameters, and ambient temperature. See below for detailed implementation methods. Figure 3 The illustrated embodiment will not be described in detail here.

[0116] In another implementation, the main control device can substitute the aforementioned distance and focal length parameters into a pre-fitted expression, and use the calculated result of the expression as the focusing parameter. This application does not limit the specific construction method of the above expression; the construction method can be related to subsequent implementations. Figure 3 The construction method described in step S306 of the embodiment is similar and will not be detailed here.

[0117] Step S106: Send focal length parameters and focus parameters to the image acquisition device so that the image acquisition device can perform video acquisition according to the focal length parameters and focus parameters.

[0118] In this way, after the image acquisition device adjusts its own focal length to the focal length indicated by the received focal length parameter and adjusts its own focus value to the focus value indicated by the received focus parameter, the first target in the acquired video image is clearer and its proportion in the video image is close to the set ratio.

[0119] In one embodiment of this application, the master control device can send PTZF (Pan Tilt ZoomFocus, azimuth angle, pitch angle, focal length, focus) coordinate commands to the image acquisition device. In the PTZF coordinate commands, the P and T values ​​can be empty, the Z value can be the aforementioned focal length parameter, and the F value can be the aforementioned focus parameter.

[0120] As can be seen from the above, by applying the solution provided in the embodiments of this application, after the main control device receives the distance between the main control device and the detected first target and the azimuth information of the first target relative to the radar, and determines that the first target is not within the field of view of the image acquisition device, the main control device can determine the rotation angle information of the gimbal that would place the first target within the field of view of the image acquisition device, and send the rotation angle information to the gimbal so that the gimbal drives the image acquisition device to rotate according to the rotation angle information; furthermore, the main control device also determines the focal length parameters and focus parameters that would make the first target occupy a set proportion in the video frame captured by the image acquisition device based on the above distance and the first size of the target of interest, and then sends the focal length parameters and focus parameters to the image acquisition device so that the image acquisition device performs video acquisition according to the focal length parameters and focus parameters.

[0121] As can be seen, before the first target enters the field of view of the image acquisition device, the main control device has already obtained the focal length and focus parameters that ensure the first target is clearly displayed and of appropriate size in the video image captured by the image acquisition device. Thus, the image acquisition device can pre-focus according to the focal length and focus parameters sent by the main control device. Consequently, after the pan-tilt unit rotates the image acquisition device according to the rotation angle information, bringing the first target into the field of view, the image acquisition device has already completed focusing and can directly acquire a video image that meets the target's clarity and size requirements. In other words, the image acquisition device can acquire a satisfactory video image as soon as the target appears within its field of view. Therefore, compared to focusing only after the target appears in the field of view, the solution provided in this application embodiment saves the time required for the image acquisition device to go from focusing to acquiring a satisfactory video image, improving the focusing efficiency of the video acquisition process.

[0122] In addition, the solution provided in this application embodiment enables the image acquisition device to capture a video image that meets the requirements as soon as the target appears in the field of view. Compared with focusing after the target appears in the field of view, the real-time target tracking is stronger, which can reduce the situation where the image acquisition device cannot capture a video image that meets the requirements due to blurring before focusing is completed. This improves the target clarity in the video image captured by the image acquisition device and improves the image quality of the video image.

[0123] In one embodiment of this application, the main control device can continuously determine the rotation angle information of the gimbal that makes the first target appear within the field of view of the image acquisition device based on the azimuth information of the first target periodically sent by the radar, and send the determined rotation angle information to the gimbal so that the gimbal drives the image acquisition device to rotate according to the rotation angle information, thereby ensuring that the first target continues to appear within the field of view of the image acquisition device. In other words, the field of view of the image acquisition device moves with the movement of the target in the scene, thereby enabling the first target to continuously appear in the video frame and achieving target tracking.

[0124] In one embodiment of this application, when there are multiple targets within the radar's field of view, the first target in step S101 above is the target with the highest following priority.

[0125] The priority of following a target is the priority when following a target, which can also be understood as the level of attention the target needs in the current scenario.

[0126] The priority of target following can be considered from multiple dimensions of factors. This application does not limit this, but will be introduced by example below.

[0127] In one scenario, the target's following priority can be determined based on at least one of the following:

[0128] 1. Types of Targets

[0129] Staff can pre-set different priorities for different types of targets based on the actual needs of the application scenario.

[0130] For example, in a vehicle management scenario, vehicles can be prioritized as high priority, while other targets can be prioritized as low priority.

[0131] 2. Target distance

[0132] Specifically, if the target distance is large, it indicates that the target is far from the image acquisition device, and it can be considered that the target requires less attention, thus determining that the target has low priority; if the target distance is small, it indicates that the target is close to the image acquisition device, and it can be considered that the target requires more attention, thus determining that the target has high priority.

[0133] 3. Target size

[0134] Specifically, if the target size is large, it can be considered that it requires more attention, thus determining that the target has a high priority; if the target size is small, it can be considered that it requires less attention, thus determining that the target has a low priority.

[0135] Of course, when determining the primary target, information from three dimensions—target type, target size, and target distance—can also be considered comprehensively. For example, for each target within the radar's field of view, priority values ​​for these three dimensions can be calculated based on the target type, target size, and target distance. Then, the priority values ​​for these three dimensions can be weighted to obtain the target's total priority value. Finally, the target with the highest total priority value is determined as the primary target with the highest following priority.

[0136] As can be seen, when determining the following priority of a target, information from multiple dimensions such as target type, target size, and target distance can be comprehensively considered. Based on the information from these multiple dimensions, the determined following priority of the target can be more reasonable and accurate.

[0137] In this embodiment, when there are multiple targets within the radar's field of view, the target with the highest following priority can be selected as the first target. This ensures that the first target appears first in the video footage captured by the subsequent image acquisition device, enabling the image acquisition device to focus on and follow the first target first, thus improving the rationality and targeting of target following.

[0138] exist Figure 1 Based on the illustrated embodiment, if the first size is a set size, after the image acquisition device performs video acquisition according to the received focal length and focus parameters, the main control device can control the image acquisition device to further fine-tune the focal length and focus value according to the actual first proportion of the first target in the video frame sent by the image acquisition device. In view of the above, this application embodiment provides a second video acquisition method.

[0139] See Figure 2 This is a flowchart illustrating the second video acquisition method provided in this application embodiment. The method includes the following steps S201-S208.

[0140] Step S201: Receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar.

[0141] If the first target is not within the field of view of the image acquisition device, proceed with the subsequent steps.

[0142] Step S202: Based on the orientation information, determine the rotation angle information of the pan-tilt unit that makes the first target within the field of view of the image acquisition device.

[0143] Step S203: Send rotation angle information to the pan-tilt unit so that the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information.

[0144] Step S204: Based on the distance and the first size of the target of interest, determine the focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device.

[0145] Step S205: Determine the focusing parameters of the image acquisition device based on the distance and focal length parameters.

[0146] Step S206: Send focal length parameters and focus parameters to the image acquisition device so that the image acquisition device can perform video acquisition according to the focal length parameters and focus parameters.

[0147] Steps S201-S206 above are the same as those mentioned above. Figure 1 In the illustrated embodiment, steps S101-S106 are the same and will not be repeated here.

[0148] Step S207: Receive the first proportion of the first target in the video frame sent by the image acquisition device.

[0149] In this embodiment, the set size is used as the estimated size of the first target. After determining the focal length and focus parameters of the image acquisition device, the clarity and size of the first target in the obtained video image roughly meet the requirements. However, the actual size of the first target often differs from the set first size. Therefore, in order to further improve the quality of the video image, the main control device can determine new focal length and focus parameters based on the actual first proportion of the first target in the video image, so as to control the image acquisition device to further fine-tune the focal length and focus value.

[0150] Similar to the meaning of setting a ratio, the first ratio can be the actual pixel ratio of the first target in the target direction of the video frame. The target direction can include the width direction of the video frame or the height direction of the video frame.

[0151] Specifically, the image acquisition device can determine the detection box of the first target in the video frame based on a pre-deployed intelligent algorithm, and then obtain the aforementioned first ratio based on the height or width of the detection box.

[0152] For example, if the height of the detection box is W2 and the width is L2, and the total height of the video frame is W0 and the width is L0, if the target direction is the height direction, the first ratio can be W2 / W0; if the target direction is the width direction, the first ratio can be L2 / L0.

[0153] Step S208: Adjust the focal length parameters according to the first ratio and the set ratio to obtain new focal length parameters, and return to execute step S205.

[0154] The focal length parameter can be adjusted using the following strategies:

[0155] If the actual first proportion is greater than the set proportion, it means that the first target occupies a large proportion of the video frame. In this case, the focal length parameter can be reduced to decrease the proportion of the first target in the video frame captured by the image acquisition device according to the new focal length parameter, so that the reduced proportion approaches the set proportion. Conversely, if the actual first proportion is less than the set proportion, it means that the first target occupies a small proportion of the video frame. In this case, the focal length parameter can be increased to increase the proportion of the first target in the video frame captured by the image acquisition device according to the new focal length parameter, so that the increased proportion approaches the set proportion.

[0156] The embodiments of this application do not limit the specific method of adjusting the focal length parameter, as long as the above adjustment strategy is met. The following examples illustrate the possible methods of adjusting the focal length parameter.

[0157] In one implementation, the ratio between a first ratio and a set ratio can be calculated. Based on the first correspondence between the obtained ratio and the adjustment ratio of the focal length parameter, the adjustment ratio is determined. Then, the product of the adjustment ratio and the focal length parameter is calculated to obtain a new focal length parameter.

[0158] In another implementation, the difference between the first ratio and the set ratio can be calculated. Based on the second correspondence between the obtained difference and the adjustment ratio of the focal length parameter, the adjustment ratio can be determined. Then, the product of the adjustment ratio and the focal length parameter can be calculated to obtain the new focal length parameter.

[0159] The first and second correspondences mentioned above can be set by staff according to the adjustment strategy described above, and will not be detailed here.

[0160] In this embodiment, on the one hand, the first size is a set size. By using the set size as the estimated size of the first target, the focal length parameter that makes the proportion of the first target in the video frame captured by the image acquisition device approach the set proportion can be calculated. This ensures that the clarity and size of the first target in the video frame roughly meet the requirements, eliminating the need to use a high-resolution radar to detect the actual size of the first target and reducing the implementation cost of the solution. On the other hand, the main control device further determines new focal length and focusing parameters based on the actual first proportion of the first target in the video frame, so as to control the image acquisition device to further fine-tune the focal length and focusing value, so that the size and clarity of the first target in the video frame can better meet the requirements and improve the image quality of the video frame.

[0161] exist Figure 1 Based on the illustrated embodiment, when determining the focusing parameters of the image acquisition device in step S105, the ambient temperature of the environment in which the image acquisition device is located can also be considered. In view of the above, this application provides a third video acquisition method.

[0162] See Figure 3This is a flowchart illustrating the third video acquisition method provided in this application embodiment. The method may include the following steps S301-S307.

[0163] Step S301: Receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar.

[0164] If the first target is not within the field of view of the image acquisition device, proceed with the subsequent steps.

[0165] Step S302: Based on the orientation information, determine the rotation angle information of the pan-tilt unit that makes the first target within the field of view of the image acquisition device.

[0166] Step S303: Send rotation angle information to the pan-tilt unit so that the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information.

[0167] Steps S301-S303 above are the same as those described above. Figure 1 In the illustrated embodiment, steps S101-S103 are the same and will not be repeated here.

[0168] Step S304: Receive the ambient temperature sent by the temperature sensor.

[0169] The aforementioned temperature sensor can be placed on the outer surface of the image acquisition device or integrated inside the image acquisition device. It is used to collect the ambient temperature of the environment in which the image acquisition device is located and send the collected ambient temperature to the main control device.

[0170] Step S305: Based on the distance and the first size of the target of interest, determine the focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device.

[0171] The above step S305 is the same as the aforementioned Figure 1 Step S104 is the same in the illustrated embodiment, and will not be repeated here.

[0172] Step S306: Determine the focusing parameters of the image acquisition device based on the distance, focal length parameters, and ambient temperature.

[0173] Specifically, the focusing parameters of the image acquisition device can be determined in the following ways.

[0174] Based on a pre-defined correspondence, the focusing parameters corresponding to the aforementioned distance, focal length, and ambient temperature are determined and used as the focusing parameters of the image acquisition device.

[0175] The above correspondence can be represented by an expression:

[0176] ; (2)

[0177] In the above expression (2), R represents the focusing parameter of the image acquisition device, also known as the focusing value, b0-bn and c0-cn represent fitting constants, n represents the order of mathematical fitting, f represents the focal length parameter, T represents the ambient temperature, T0 represents the set temperature, k represents the focusing motor transmission ratio of the image acquisition device, specifically the ratio of the displacement of the focal plane to the focusing code value of the focusing motor, D represents the distance, also known as the object distance, and R0 represents the set focusing parameter at the set temperature.

[0178] The aforementioned focusing motor can be either a focusing motor used to control the movement of the optical lens in an image acquisition device, or a focusing motor used to control the movement of the detector in an image acquisition device, wherein the detector includes a photosensitive element array. It is evident that regardless of the type of focusing motor, its function is to change the distance between the optical lens and the photosensitive element.

[0179] By substituting the distance, focal length, and ambient temperature into the above expression, the focusing parameters of the image acquisition device can be calculated. It is evident that, based on a pre-defined correspondence, the focusing parameters of the image acquisition device can be obtained conveniently and efficiently.

[0180] The above expression can be obtained by fitting calibration data, which includes the sample temperature and the focusing parameters of the sample with clear focus at the sample temperature. The construction process of the above expression is described below through steps A-D.

[0181] Step A: Calibrate the image acquisition equipment.

[0182] The optical lenses of image acquisition equipment are generally designed for room temperature (20℃) and infinity object distance. In this step, the focus value R0 of the image acquisition equipment can be determined to be clear under the conditions of room temperature T0 and infinity object distance. The above process can be called calibrating the image acquisition equipment.

[0183] Step B: With the focal length fixed, fit the relationship between ambient temperature and focal value.

[0184] The inventors discovered in practice that, with a fixed focal length f of the image acquisition device, the relationship between the focus value R and the ambient temperature T is constant. Therefore, this relationship can be fitted based on optical design simulation data or experimental test data. The aforementioned optical design simulation data or experimental test data includes the sample temperature and calibration data of the focus parameters of samples with clear focus at that temperature, corresponding to the aforementioned calibration data.

[0185] For example, the above relationship can be fitted using a quadratic function to obtain the focus value R that ensures a sharp image at a fixed focal length parameter f and any temperature T.

[0186] ; (3)

[0187] In the above expression (3), a1 and a2 represent fitting constants, T0 represents the above normal temperature, and R0 represents the focus value of the image acquisition device when the object distance is infinitely far and the object temperature is T0.

[0188] Step C: Fit the relationship between any focal length, any ambient temperature and the focus value.

[0189] At different focal lengths, the fitting constants a1 and a2 in the above expression (3) can be regarded as a continuous array. This array and the corresponding focal length can be fitted by a function of multiple times. Based on this, based on the initially calibrated (R0, T0), the focus value R that allows the image to be focused clearly at any focal length f and any temperature T can be obtained:

[0190] ; (4)

[0191] In the above expression (4), b0-bn and c0-cn represent fitting constants, and n represents the order of mathematical fitting.

[0192] Step D: Combine object distance to fit the relationship between focal length, object distance, ambient temperature and focus value.

[0193] Specifically, the object distance D and the focal plane offset of the image acquisition device The relationship between them can be represented by the following expression:

[0194] ; (5)

[0195] Due to focal plane offset The relationship between the focal length and the focal plane offset R is determined by the focusing motor transmission ratio k. Therefore, the relationship between the focusing motor transmission ratio k and the focal plane offset can be calculated. The product of will Convert to R. Based on this, and based on the initially calibrated (R0, T0), we can obtain the expression for the focus value R that results in a clear image under any focal length parameter f, any temperature T, and any object distance D, which is the aforementioned expression (2):

[0196] (2)

[0197] Step S307: Send focal length parameters and focus parameters to the image acquisition device so that the image acquisition device can perform video acquisition according to the focal length parameters and focus parameters.

[0198] As can be seen, in this embodiment, when determining the focusing parameters of the image acquisition device, not only the focal length and target distance are considered, but also the influence of the ambient temperature of the environment where the image acquisition device is located on the focusing. In this way, combining the ambient temperature to determine the focusing parameters improves the accuracy of the determined focusing parameters, enabling the image acquisition device to focus more clearly based on the focusing parameters, and further improving the clarity of the target in the video image.

[0199] exist Figure 1 Based on the illustrated embodiment, the focal length and focus parameters can be adjusted in a timely manner when the target's pose changes. In view of the above, this application provides a fourth video acquisition method.

[0200] See Figure 4 This is a flowchart illustrating the fourth video acquisition method provided in this application embodiment. The method may include the following steps S401-S407.

[0201] Step S401: Receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar.

[0202] If the first target is not within the field of view of the image acquisition device, proceed with the subsequent steps.

[0203] Step S402: Based on the orientation information, determine the rotation angle information of the pan-tilt unit that makes the first target within the field of view of the image acquisition device.

[0204] Step S403: Send rotation angle information to the pan-tilt unit so that the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information.

[0205] Step S404: Based on the distance and the first size of the target of interest, determine the focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device.

[0206] Step S405: Determine the focusing parameters of the image acquisition device based on the distance and focal length parameters.

[0207] Step S406: Send focal length parameters and focus parameters to the image acquisition device so that the image acquisition device can perform video acquisition according to the focal length parameters and focus parameters.

[0208] Steps S401-S406 above are the same as those described above. Figure 1 In the illustrated embodiment, steps S101-S106 are the same and will not be repeated here.

[0209] Step S407: If it is determined that the pose of the first target has changed, adjust the focal length parameter according to the actual first ratio and the set ratio of the first target in the video frame sent by the image acquisition device to obtain the new focal length parameter, and return to execute step S405.

[0210] A change in the pose of the first target can include a change in the target distance or a change in the target orientation.

[0211] Specifically, the main control device can determine whether the first target has sent a pose change in the following way.

[0212] First, obtain the pose information of the first target, and based on the pose information, determine whether the pose of the first target has changed.

[0213] Depending on the pose information, the method for determining the pose change of the first target will also be different, which will be introduced in detail below.

[0214] In one scenario, if the aforementioned pose information is the distance of the first target transmitted by the radar, the main control device can calculate the difference between the latest received distance and the previously received distance. If the difference is greater than a set distance, it can be determined that the pose of the first target has changed.

[0215] Since radar can transmit target range to the main control equipment at a certain frequency, when the main control equipment determines that the difference between two received ranges is large, it indicates that the distance between the target and the image acquisition equipment has changed significantly within a short period of time. At this point, the size of the target in the video frame often changes, meaning the pixel ratio of the target in the video frame often changes. Therefore, the main control equipment can determine the change in the pose of the first target and subsequently control the image acquisition equipment to refocus and re-focus on the first target.

[0216] In another scenario, if the pose information is the pose information of the first target sent by the image acquisition device, the main control device can calculate the difference between the latest received pose information and the previously received pose information. If the difference is greater than a set difference, it can be determined that the first target has sent a pose change.

[0217] Since the image acquisition device can send attitude information to the main control device at a certain frequency, when the main control device determines that the difference between two received attitude information is large, it indicates that the target's attitude has changed significantly in a short period of time. At this time, the pixel ratio of the target in the video frame often changes.

[0218] The following is through Figure 5a and Figure 5bThis provides an intuitive explanation of how changes in the target's pose lead to changes in the pixel ratio of the target in the video frame.

[0219] See Figure 5a This is a schematic diagram of the first target posture provided in the embodiments of this application, showing the posture of the first target in the video frame sent by the image acquisition device to the main control device at the first moment; see also Figure 5b This is a schematic diagram of the second target posture provided in the embodiments of this application, showing the posture of the first target in the video frame sent by the image acquisition device to the main control device at a second moment after the first moment.

[0220] As can be seen, at the first moment, the width of the first target in the video frame is L3 and the height is W3. At the second moment, the first target tilts, that is, its posture changes. At this time, the width of the first target in the video frame becomes L4 and the height becomes W4. Since L4 > L3, if the target's proportion in the video frame is defined as the percentage of pixels in the width direction of the video frame, then it is clear that the percentage of pixels in the width direction of the first target in the second moment is greater than the percentage in the first moment.

[0221] Therefore, in this case, in order to ensure that the pixel ratio of the first target in the video frame can be maintained at the set ratio, the main control device can subsequently control the image acquisition device to refocus and re-focus on the first target.

[0222] Specifically, the method by which the main control device adjusts the focal length parameters based on the actual first ratio and the set ratio of the first target in the video frame has been described above. Figure 2 The steps in step S208 of the illustrated embodiment are described and will not be repeated here.

[0223] In this embodiment, when the main control device determines that the first target has changed its pose, it can promptly re-determine the focal length and focus parameters based on the latest actual first ratio and the set ratio of the first target in the video frame. This allows the image acquisition device to promptly refocus and re-focus on the first target when the pose change causes a change in the pixel ratio of the first target in the video frame. As a result, the pixel ratio of the first target in the video frame can be stably maintained at the set ratio, improving the stability and targeting of the target tracking.

[0224] As can be seen from the foregoing embodiments, in the solution provided by this application, before the target to be followed enters the field of view of the image acquisition device, the main control device can pre-control the image acquisition device to adjust the zoom value and focus value so that the proportion of the target in the video picture is close to the set ratio. This allows the image acquisition device to capture a video picture that meets the requirements as soon as the target appears in the field of view of the image acquisition device, saving the time that the image acquisition device needs to spend from focusing to capturing a video picture that meets the requirements, and improving the focusing efficiency of the video acquisition process.

[0225] Furthermore, when the main control device detects a change in the distance or posture of the target, it can control the image acquisition device to adjust the zoom and focus values ​​in real time based on the change in the size of the target's recognition box in the video frame. This ensures that the target's proportion in the video frame is close to a set ratio. In this way, whether the difference in the recognition box size is caused by different target sizes or by the target moving at different distances or moving quickly, the zoom and focus values ​​of the image acquisition device can be re-determined based on the pixel proportion occupied by the recognition box, ensuring clear real-time target tracking and improving the stability and targeting during target tracking. In addition, the main control device can control the rotation of the gimbal in real time based on the azimuth information sent by the radar, so that the target can be stably kept in the center area of ​​the video frame.

[0226] In summary, the solution provided in this application can effectively improve the real-time performance and accuracy of following a moving target, and reduce the probability of losing the target due to out-of-focus images or abnormal target proportions during the entire target following process.

[0227] Corresponding to the video acquisition method described above, this application also provides a video acquisition system.

[0228] See Figure 6 This is a schematic diagram of a first type of video acquisition system provided in an embodiment of this application. The system includes a main control device 601, a radar 602, an image acquisition device 603, and a pan-tilt unit 604 that carries the image acquisition device.

[0229] Radar 602 is used to perform target detection and determine the distance between itself and the detected first target and the azimuth information of the first target relative to radar 602;

[0230] The main control device 601 is used to, if the first target is not within the field of view of the image acquisition device 603, determine the rotation angle information of the pan-tilt unit 604 that would place the first target within the field of view of the image acquisition device 603 based on the orientation information; send the rotation angle information to the pan-tilt unit 604; determine the focal length parameter that would make the first target occupy a set proportion in the video frame captured by the image acquisition device 603 based on the distance and the first size of the target of interest; determine the focus parameter of the image acquisition device 603 based on the distance and the focal length parameter; and send the focal length parameter and the focus parameter to the image acquisition device 603.

[0231] The pan-tilt unit 604 is used to rotate the image acquisition device 603 according to the received rotation angle information;

[0232] Image acquisition device 603 is used to acquire video according to the received focal length and focus parameters.

[0233] As can be seen from the above, in the video acquisition system provided in this application embodiment, after the main control device receives the distance between the detected first target and the radar and the azimuth information of the first target relative to the radar, and determines that the first target is not within the field of view of the image acquisition device, the main control device can determine the rotation angle information of the gimbal that makes the first target within the field of view of the image acquisition device, and send the rotation angle information to the gimbal. Thus, the gimbal can drive the image acquisition device to rotate according to the rotation angle information. Furthermore, the main control device also determines the focal length parameters and focus parameters that make the first target occupy a set proportion in the video frame acquired by the image acquisition device based on the above-mentioned distance and the first size of the target of interest, and then sends the focal length parameters and focus parameters to the image acquisition device. In this way, the image acquisition device performs video acquisition according to the focal length parameters and focus parameters.

[0234] As can be seen, before the first target enters the field of view of the image acquisition device, the main control device has already obtained the focal length and focus parameters that ensure the first target is clearly displayed and of appropriate size in the video image captured by the image acquisition device. Thus, the image acquisition device can pre-focus according to the focal length and focus parameters sent by the main control device. Consequently, after the pan-tilt unit rotates the image acquisition device according to the rotation angle information, bringing the first target into the field of view, the image acquisition device has already completed focusing and can directly acquire a video image that meets the target's clarity and size requirements. In other words, the image acquisition device can acquire a satisfactory video image as soon as the target appears within its field of view. Therefore, compared to focusing only after the target appears in the field of view, the solution provided in this application embodiment saves the time required for the image acquisition device to go from focusing to acquiring a satisfactory video image, improving the focusing efficiency of the video acquisition process.

[0235] In addition, the solution provided in this application embodiment enables the image acquisition device to capture a video image that meets the requirements as soon as the target appears in the field of view of the image acquisition device. Compared with focusing after the target appears in the field of view, the real-time performance of target tracking is stronger, which can reduce the situation where the image acquisition device cannot capture a video image that meets the requirements due to out-of-focus conditions before focusing is completed, and improve the target clarity in the video image captured by the image acquisition device.

[0236] In one embodiment of this application, the system further includes a temperature sensor for collecting ambient temperature and sending the ambient temperature to the main control device.

[0237] In this case, the main control device can determine the focusing parameters of the image acquisition device based on the aforementioned distance, focal length parameters, and ambient temperature. For details, please refer to the aforementioned method embodiments.

[0238] As can be seen, in this embodiment, when the main control device determines the focusing parameters of the image acquisition device, it not only considers the focal length and target distance, but also the influence of the ambient temperature of the environment where the image acquisition device is located on the focusing. In this way, combining the ambient temperature to determine the focusing parameters improves the accuracy of the determined focusing parameters, enabling the image acquisition device to focus more clearly based on the focusing parameters, and further improving the clarity of the target in the video image.

[0239] In one embodiment of this application, the temperature sensor is disposed on the outer surface of the image acquisition device.

[0240] In this way, the temperature sensor is in close contact with the image acquisition device, which can better capture the ambient temperature of the environment in which the image acquisition device is located, thus improving the accuracy of the captured ambient temperature.

[0241] In one embodiment of this application, the image acquisition device is provided with a driver board, which is used to adjust the focal length of the image acquisition device based on the received focal length parameters, and to adjust the focus value of the image acquisition device based on the received focus parameters.

[0242] The driver board is a piece of hardware specifically designed to control the zoom and focus of the image acquisition device. After receiving the focal length and focus parameters sent by the main control device, the driver board can accurately adjust the focal length and focus value of the image acquisition device.

[0243] Based on the above system embodiments, this application also provides another specific video acquisition system.

[0244] See Figure 7 This is a schematic diagram of the second video acquisition system provided in the embodiments of this application, and... Figure 6Compared to the system shown, the above system includes not only the main control device 601, radar 602, image acquisition device 603, and pan-tilt unit 604, but also a temperature sensor 605, a driver board 606, and an image display 607.

[0245] The functions of the temperature sensor 605 and the driver board 606 have been described above. The image display 607 is connected to the main control device 601 and is used to receive and display the video acquired by the image acquisition device 603 sent by the main control device 601.

[0246] Corresponding to the video acquisition method described above, this application also provides a video acquisition device.

[0247] See Figure 8 This is a schematic diagram of a video acquisition device provided in an embodiment of this application. The device includes the following modules:

[0248] The information receiving module 801 is used to receive the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar.

[0249] The rotation angle information determination module 802 is used to determine the rotation angle information of the pan-tilt unit that makes the first target fall within the field of view of the image acquisition device based on the orientation information if the first target is not within the field of view of the image acquisition device.

[0250] The rotation angle information sending module 803 is used to send the rotation angle information to the pan-tilt unit so that the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information;

[0251] The focal length parameter determination module 804 is used to determine a focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device based on the distance and the first size of the target of interest.

[0252] The focus parameter determination module 805 is used to determine the focus parameters of the image acquisition device based on the distance and focal length parameters;

[0253] The parameter sending module 806 is used to send the focal length parameter and focus parameter to the image acquisition device so that the image acquisition device can perform video acquisition according to the focal length parameter and focus parameter.

[0254] As can be seen, before the first target enters the field of view of the image acquisition device, the main control device has already obtained the focal length and focus parameters that ensure the first target is clearly displayed and of appropriate size in the video image captured by the image acquisition device. Thus, the image acquisition device can pre-focus according to the focal length and focus parameters sent by the main control device. Consequently, after the pan-tilt unit rotates the image acquisition device according to the rotation angle information, bringing the first target into the field of view, the image acquisition device has already completed focusing and can directly acquire a video image that meets the target's clarity and size requirements. In other words, the image acquisition device can acquire a satisfactory video image as soon as the target appears within its field of view. Therefore, compared to focusing only after the target appears in the field of view, the solution provided in this application embodiment saves the time required for the image acquisition device to go from focusing to acquiring a satisfactory video image, improving the focusing efficiency of the video acquisition process.

[0255] In addition, the solution provided in this application embodiment enables the image acquisition device to capture a video image that meets the requirements as soon as the target appears in the field of view. Compared with focusing after the target appears in the field of view, the real-time target tracking is stronger, which can reduce the situation where the image acquisition device cannot capture a video image that meets the requirements due to blurring before focusing is completed. This improves the target clarity in the video image captured by the image acquisition device and improves the image quality of the video image.

[0256] In one embodiment of this application, the first dimension is:

[0257] The set size.

[0258] In this way, by pre-setting the first size of the target of interest to be followed in the current scene, the first size can be used as the estimated or ideal size of the first target. Subsequently, based on the first size, the focal length parameter that makes the proportion of the first target in the video frame captured by the image acquisition device approach the set ratio can be calculated, which helps to make the target size in the frame captured by the image acquisition device appropriate.

[0259] In one embodiment of this application, the first dimension is:

[0260] The size of the first target as measured by the radar.

[0261] In this way, the first size is the accurate size of the first target measured by the radar. Subsequently, based on the accurate size, more precise calculations can be made to ensure that the first target occupies a set proportion of the video image captured by the image acquisition device, thereby making the target size in the image captured by the image acquisition device appropriate.

[0262] In one embodiment of this application, if the first dimension is a predetermined dimension, the device further includes:

[0263] The first ratio receiving module is used to receive the actual first ratio of the first target in the video frame sent by the image acquisition device;

[0264] The first parameter adjustment module is used to adjust the focal length parameter according to the first ratio and the set ratio to obtain a new focal length parameter and trigger the focus parameter determination module 805.

[0265] In this embodiment, on the one hand, the first size is a set size. By using the set size as the estimated size of the first target, the focal length parameter that makes the proportion of the first target in the video frame captured by the image acquisition device approach the set proportion can be calculated. This ensures that the clarity and size of the first target in the video frame roughly meet the requirements, eliminating the need to use a high-resolution radar to detect the actual size of the first target and reducing the implementation cost of the solution. On the other hand, the main control device further determines new focal length and focusing parameters based on the actual first proportion of the first target in the video frame, so as to control the image acquisition device to further fine-tune the focal length and focusing value, so that the size and clarity of the first target in the video frame can better meet the requirements and improve the image quality of the video frame.

[0266] In one embodiment of this application, the set ratio is: the percentage of pixels of the target in the target direction of the video frame.

[0267] The focal length parameter determination module 804 is specifically used to obtain the focal length parameter that makes the first target occupy a set proportion in the video frame captured by the image acquisition device, according to the following expression. :

[0268] ;

[0269] Wherein, num represents the number of pixels occupied by the first target in the target direction of the video frame, calculated based on the set ratio. The pixel size of the image acquisition device is represented by D, the distance is represented by L, and the first dimension of the target of interest is represented by the component in the target direction.

[0270] The above expression allows for convenient and accurate calculation of the focal length parameter that ensures the first target occupies a set proportion in the video frame captured by the image acquisition device.

[0271] In one embodiment of this application, the focusing parameter determination module 805 includes:

[0272] An ambient temperature receiving submodule is used to receive the ambient temperature sent by a temperature sensor.

[0273] The focusing parameter determination submodule determines the focusing parameters of the image acquisition device based on the distance, focal length parameters, and ambient temperature.

[0274] As can be seen, in this embodiment, when determining the focusing parameters of the image acquisition device, not only the focal length and target distance are considered, but also the influence of the ambient temperature of the environment where the image acquisition device is located on the focusing. In this way, combining the ambient temperature to determine the focusing parameters improves the accuracy of the determined focusing parameters, enabling the image acquisition device to focus more clearly based on the focusing parameters, and further improving the clarity of the target in the video image.

[0275] In one embodiment of this application, the focusing parameter determination submodule is specifically used to determine the focusing parameters corresponding to the distance, focal length, and ambient temperature based on a pre-set correspondence, as the focusing parameters of the image acquisition device. The correspondence is obtained based on calibration data fitting, and the calibration data includes: sample temperature and the focusing parameters of samples with clear focus at the sample temperature.

[0276] As can be seen, based on the pre-set correspondence, the focusing parameters of the image acquisition device can be obtained conveniently and efficiently.

[0277] In one embodiment of this application, the rotation angle information determination module 802 is specifically used to determine the rotation angle information of the gimbal that makes the first target located in the center area of ​​the field of view of the image acquisition device based on the orientation information.

[0278] In this way, after the main control device sends the rotation angle information to the pan-tilt unit, the pan-tilt unit drives the image acquisition device to rotate according to the rotation angle information, so that the central area of ​​the field of view of the image acquisition device includes the aforementioned first target. In other words, the first target appears in the central area of ​​the video image captured by the image acquisition device, making the first target more obvious and prominent in the video image, which is convenient for subsequent analysis of the target in the video image.

[0279] In one embodiment of this application, when there are multiple targets within the field of view of the radar, the first target is the target with the highest following priority.

[0280] In this embodiment, when there are multiple targets within the radar's field of view, the target with the highest following priority can be selected as the first target. This ensures that the first target appears first in the video footage captured by the subsequent image acquisition device, enabling the image acquisition device to focus on and follow the first target first, thus improving the rationality and targeting of target following.

[0281] In one embodiment of this application, the target's following priority is determined according to at least one of the following information:

[0282] Target type, target distance, target size.

[0283] As can be seen, when determining the following priority of a target, information from multiple dimensions such as target type, target size, and target distance can be comprehensively considered. Based on the information from these multiple dimensions, the determined following priority of the target can be more reasonable and accurate.

[0284] In one embodiment of this application, the apparatus further includes:

[0285] The second parameter adjustment module is used to adjust the focal length parameter according to the actual first ratio of the first target in the video frame and the set ratio, based on the latest first ratio of the first target sent by the image acquisition device, when it is determined that the first target has undergone a pose change, to obtain a new focal length parameter and trigger the focus parameter determination module 805.

[0286] In this embodiment, when the main control device determines that the first target has changed its pose, it can promptly re-determine the focal length and focus parameters based on the latest actual first ratio and the set ratio of the first target in the video frame. This allows the image acquisition device to promptly refocus and re-focus on the first target when the pose change causes a change in the pixel ratio of the first target in the video frame. As a result, the pixel ratio of the first target in the video frame can be stably maintained at the set ratio, improving the stability and targeting of the target tracking.

[0287] In the technical solution of this application, the operations of obtaining, storing, using, processing, transmitting, providing and disclosing user personal information are all carried out with the user's authorization.

[0288] Corresponding to the above video acquisition method, this application embodiment also provides a master control device, a computer-readable storage medium, and a computer program.

[0289] This application also provides a master control device, such as... Figure 9 As shown, it includes:

[0290] Memory 901 is used to store computer programs;

[0291] When processor 902 executes a program stored in memory 901, it performs the following steps:

[0292] Furthermore, the aforementioned main control device may also include a communication bus and / or a communication interface, and the processor 902, the communication interface, and the memory 901 communicate with each other through the communication bus.

[0293] The communication bus mentioned in the above-mentioned main control device can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. This communication bus can be divided into address bus, data bus, control bus, etc. For ease of illustration, only one thick line is used to represent it in the diagram, but this does not mean that there is only one bus or one type of bus.

[0294] The communication interface is used for communication between the main control device and other devices.

[0295] The memory may include random access memory (RAM) or non-volatile memory (NVM), such as at least one disk storage device. Optionally, the memory may also be at least one storage device located remotely from the aforementioned processor.

[0296] The processors mentioned above can be general-purpose processors, including central processing units (CPUs), network processors (NPs), etc.; they can also be digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0297] In another embodiment provided in this application, a computer-readable storage medium is also provided, which stores a computer program that, when executed by a processor, implements the steps of the video acquisition method described above.

[0298] In another embodiment provided in this application, a computer program product containing instructions is also provided, which, when run on a computer, causes the computer to execute any of the video acquisition methods described above.

[0299] In the above embodiments, implementation can be achieved entirely or partially through software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented entirely or partially in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a solid-state drive (SSD), etc.

[0300] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0301] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments for apparatus, system, main control device, and storage medium are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0302] The above description is merely a preferred embodiment of this application and is not intended to limit the scope of protection of this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application are included within the scope of protection of this application.

Claims

1. A video acquisition method, characterized in that: The method comprises: receiving the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar; If the first target is not within the field of view of the image acquisition device, determining, based on the orientation information, the rotation angle information of the pan / tilt head so that the first target is within the field of view of the image acquisition device; Sending the rotation angle information to the pan-tilt platform, so that the pan-tilt platform drives the image acquisition device to rotate according to the rotation angle information; Based on the distance and a first size of the object of interest, determining a focal length parameter that enables the first object to occupy a set proportion in the video image captured by the image acquisition device; Determining a focusing parameter of the image acquisition device based on the distance and focal length parameters; The focal length parameter and the focus parameter are sent to the image acquisition device, so that the image acquisition device performs video acquisition according to the focal length parameter and the focus parameter.

2. The method according to claim 1, characterized in that The first dimension is: a set size; or The size of the first target obtained by the radar measurement.

3. The method according to claim 2, characterized in that If the first size is a set size, the method further includes: Receiving a first actual proportion of the first target in the video picture sent by the image acquisition device; According to the first ratio and the set ratio, the focal length parameter is adjusted to obtain a new focal length parameter, and the step of determining the focusing parameter of the image acquisition device based on the distance and the focal length parameter is returned to be executed.

4. The method according to claim 1, characterized in that: The set ratio is: the pixel ratio of the target in the target direction of the video screen, and the determining of the focal length parameter that makes the first target account for the set ratio in the video screen captured by the image acquisition device based on the distance and the first size of the target of interest includes: The focal length parameter that makes the first target account for a set proportion in the video image captured by the image acquisition device is obtained according to the following expression: : ； Wherein, num represents the number of pixels occupied by the first target in the target direction of the video screen, calculated based on the set ratio, represents the pixel size of the image acquisition device, D represents the distance, and L represents the component of the first size of the target of interest in the target direction.

5. The method according to claim 1, characterized in that The step of determining the focusing parameter of the image acquisition device based on the distance and the focal length parameter comprises: Receive the ambient temperature sent by the temperature sensor; Based on the distance, focal length parameter and ambient temperature, a focusing parameter of the image acquisition device is determined.

6. The method according to claim 5, characterized in that The determining of the focusing parameter of the image acquisition device based on the distance, the focal length parameter and the ambient temperature includes: Based on a preset correspondence, the focusing parameters corresponding to the distance, focal length parameters and ambient temperature are determined as focusing parameters of the image acquisition device, wherein the corresponding relationship is obtained based on calibration data fitting, and the calibration data includes: sample temperature and sample focusing parameters with clear focus at the sample temperature.

7. The method according to claim 1, characterized in that The step of determining, based on the orientation information, the rotation angle information of the pan / tilt head so that the first target is within the field of view of the image acquisition device comprises: Based on the orientation information, the rotation angle information of the pan / tilt head that makes the first target be located in the center area of ​​the field of view of the image acquisition device is determined.

8. The method according to any one of claims 1 to 7, characterized in that When there are multiple targets within the field of view of the radar, the first target is: the target with the highest following priority.

9. The method according to claim 8, characterized in that The target's follow priority is determined by at least one of the following information: Target type, target distance, target size.

10. The method according to any one of claims 1 to 7, characterized in that The method further comprises: When it is determined that the first target has changed its position, the focal length parameter is adjusted according to the actual first proportion of the first target in the video screen and the set proportion recently sent by the image acquisition device to obtain a new focal length parameter, and the step of determining the focus parameter of the image acquisition device based on the distance and focal length parameter is returned to execute.

11. A video acquisition system, characterized in that: The system includes: a main control device, a radar, an image acquisition device, and a pan / tilt platform carrying the image acquisition device, wherein: The radar is used to perform target detection, determine the distance to the detected first target and the azimuth information of the first target relative to the radar; The main control device is used to determine, based on the orientation information, the rotation angle information of the pan / tilt head so that the first target is within the field of view of the image acquisition device if the first target is not within the field of view of the image acquisition device; send the rotation angle information to the pan / tilt head; determine, based on the distance and the first size of the target of interest, a focal length parameter so that the first target occupies a set proportion in the video image captured by the image acquisition device; determine a focus parameter of the image acquisition device based on the distance and the focal length parameter; and send the focal length parameter and the focus parameter to the image acquisition device; The pan / tilt is used to drive the image acquisition device to rotate according to the received rotation angle information; The image acquisition device is used to perform video acquisition according to the received focal length parameter and focus parameter.

12. The system according to claim 11, characterized in that The system further comprises: a temperature sensor, wherein: The temperature sensor is used to collect the ambient temperature and send the ambient temperature to the main control device; The main control device determines the focus parameter of the image acquisition device based on the distance and focal length parameters, including: Based on the distance, focal length parameter and ambient temperature, a focusing parameter of the image acquisition device is determined.

13. The system according to claim 12, characterized in that The temperature sensor is arranged on the outer surface of the image acquisition device.

14. The system according to claim 11, characterized in that The image acquisition device is provided with a driving board, wherein: The driving board is used to adjust the focal length of the image acquisition device based on the received focal length parameter, and to adjust the focus value of the image acquisition device based on the received focus parameter.

15. A video acquisition device, characterized in that: The device comprises: An information receiving module, used for receiving the distance between the radar and the detected first target and the azimuth information of the first target relative to the radar; A rotation angle information determination module, configured to determine, based on the orientation information, rotation angle information of the pan / tilt head so that the first target is within the field of view of the image acquisition device if the first target is not within the field of view of the image acquisition device; A rotation angle information sending module, used for sending the rotation angle information to the pan-tilt head, so that the pan-tilt head drives the image acquisition device to rotate according to the rotation angle information; A focal length parameter determination module, configured to determine, based on the distance and a first size of the object of interest, a focal length parameter that enables the first object to occupy a set proportion in the video image captured by the image acquisition device; A focusing parameter determination module, used to determine a focusing parameter of the image acquisition device based on the distance and focal length parameters; The parameter sending module is used to send the focal length parameter and the focus parameter to the image acquisition device, so that the image acquisition device performs video acquisition according to the focal length parameter and the focus parameter.

16. The device according to claim 15, characterized in that The first size is: a set size; or a size of the first target measured by the radar; or If the first size is a set size, the device further includes: a first ratio receiving module, used to receive the actual first ratio of the first target in the video picture sent by the image acquisition device; a first parameter adjustment module, used to adjust the focal length parameter according to the first ratio and the set ratio, obtain a new focal length parameter, and trigger a focus parameter determination module; or The set ratio is: the pixel ratio of the target in the target direction of the video screen. The focal length parameter determination module is specifically used to obtain the focal length parameter that makes the first target account for the set ratio in the video screen captured by the image acquisition device according to the following expression: : ; wherein num represents the number of pixels occupied by the first target in the target direction of the video screen calculated based on the set ratio, represents the pixel size of the image acquisition device, D represents the distance, and L represents the component of the first size of the object of interest in the direction of the object; or The focusing parameter determination module includes: an ambient temperature receiving submodule, which is used to receive the ambient temperature sent by the temperature sensor; a focusing parameter determination submodule, which determines the focusing parameter of the image acquisition device based on the distance, focal length parameter and ambient temperature; or The focusing parameter determination submodule is specifically used to determine the focusing parameters corresponding to the distance, focal length parameter and ambient temperature based on a preset corresponding relationship as the focusing parameters of the image acquisition device, wherein the corresponding relationship is obtained based on calibration data fitting, and the calibration data includes: sample temperature and sample focusing parameters with clear focus at the sample temperature; or The rotation angle information determination module is specifically used to determine the rotation angle information of the pan / tilt head so that the first target is located in the center area of ​​the field of view of the image acquisition device based on the orientation information; or When there are multiple targets within the field of view of the radar, the first target is: the target with the highest following priority; or The following priority of the target is determined according to at least one of the following information: target type, target distance, and target size; or The device also includes: a second parameter adjustment module, which is used to adjust the focal length parameter according to the actual first proportion of the first target in the video screen and the set proportion recently sent by the image acquisition device when it is determined that the first target has changed its posture, so as to obtain a new focal length parameter and trigger the focus parameter determination module.

17. A main control device, characterized in that: include: Memory, used to store computer programs; A processor, for implementing any of the methods described in claims 1-10 when executing a program stored in a memory.

18. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 10 is implemented.

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