Aerial photography rail pushing zooming method and system

Abstract

The invention relates to the technical field of unmanned aerial vehicle image processing, in particular to an aerial photography rail pushing zooming method and system. The method comprises the steps that the fixed acceleration of the unmanned aerial vehicle is calculated according to the obtained initial shooting distance between a shooting device and a shooting object, a specified frame rate, a specified frame zoom ratio and a progress judgment threshold value, and the shooting device is arranged on the unmanned aerial vehicle; and when a video is shot at a specified frame rate and the shooting device is controlled to carry out digital zooming on the shot video according to a specified frame zooming ratio, the unmanned aerial vehicle is controlled to fly away from a shot object in a uniformly accelerated manner along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, so that aerial photography push-rail zooming is realized. According to the invention, the flight control difficulty of the unmanned aerial vehicle is simplified, more flexible digital zooming and flight speed control matched with the digital zooming can be realized, so that the automatic management of rail pushing zooming is realized, the video shooting quality is improved, and the method can be widely applied to multiple fields such as film shooting and advertisement production.

Description

Technical Field

[0001] The present invention relates to the technical field of unmanned aerial vehicle image processing, and in particular to an aerial photography push-track zoom method and system. Background Art

[0002] Hitchcock zoom, also known as sliding zoom or dolly zoom, is a shooting method that, when shooting video, moves the camera (or video camera) backward or forward while zooming to keep the size of the subject in the picture unchanged while significantly changing the size of the background. It has a strong visual impact.

[0003] In traditional video shooting, the realization of Hitchcock zoom relies on manual operation: the photographer needs to manually control the optical zoom of the lens and use the slide rail to push the camera to move. This process is not only complicated to operate, but also has high requirements for equipment and technology.

[0004] In recent years, with the rapid development of drone technology, some drone-based solutions have emerged, which simplify the implementation process of Hitchcock zoom by controlling the camera optical zoom through the autonomous movement of the drone. However, these solutions still have certain limitations. For example, existing drones usually need to carry cameras equipped with optical zoom lenses, and the limited load space and strict hardware integration requirements of drones further raise the standards for the performance of optical zoom lenses, resulting in a significant increase in economic costs. In addition, existing solutions often only support a limited number of zoom points and lack the ability to automatically control the Hitchcock zoom, which limits their flexibility and practicality. Summary of the invention

[0005] In order to solve the problems in the related art, the embodiments of the present disclosure provide an aerial photography zoom method and system.

[0006] In a first aspect, an embodiment of the present disclosure provides an aerial photography zoom method, comprising: Acquire an initial shooting distance between a shooting device and a shooting object, a specified frame rate, a specified frame zoom ratio, and a progress determination threshold, wherein the shooting device is arranged on a drone, and the progress determination threshold includes any one of the following: a maximum aerial zoom time, a maximum zoom ratio, and a maximum flight speed; Calculate the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate, and the specified frame zoom factor; While shooting video at the specified frame rate and controlling the shooting device to digitally zoom the shot video according to the specified frame zoom ratio, the drone is controlled to fly away from the shooting object with uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, thereby realizing aerial photography push-track zoom.

[0007] According to an embodiment of the present disclosure, it also includes: During the aerial photography zooming process, obtaining a progress determination parameter corresponding to the progress determination threshold, wherein the progress determination parameter includes any one of the aerial photography zooming time, zoom multiple, and flight speed; When the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography tracking and zooming process is ended.

[0008] According to an embodiment of the present disclosure: The maximum aerial photography zoom time is the minimum value between the first maximum aerial photography zoom time and the second maximum aerial photography zoom time, wherein the first maximum aerial photography zoom time is related to the maximum zoom factor, and the second maximum aerial photography zoom time is related to the maximum flight speed.

[0009] According to an embodiment of the present disclosure: The first maximum aerial zoom time With the maximum zoom ratio The relationship between them satisfies the following formula: ; The second maximum aerial zoom time With the maximum flight speed The relationship between them satisfies the following formula: ; Maximum aerial zoom time With the first maximum aerial zoom time and the second largest aerial zoom time The relationship between them satisfies the following formula: ; Wherein, d is the initial shooting distance, is the specified frame rate, and k is the specified frame scaling factor.

[0010] According to an embodiment of the present disclosure, when the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography push-track zoom process is ended, including: When the aerial zoom time t reaches or exceeds the maximum aerial zoom time The aerial photography zoom process ends when the camera is turned on.

[0011] According to an embodiment of the present disclosure, the method further includes: When the shooting device is controlled to perform digital zoom on the shot video according to the specified frame zoom ratio, each picture frame of the shot video is enlarged by at least 2 pixels frame by frame; The zoom factor is related to the specified frame magnification.

[0012] According to an embodiment of the present disclosure: When each picture frame of the captured video is enlarged by at least 2 pixels frame by frame, the specified frame zoom ratio k satisfies the following formula: ; The relationship between the zoom factor n and the specified frame scaling factor k satisfies the following formula: , ; Wherein, t is the aerial zoom time, is the zoom time of the large aerial photography, is the maximum flight speed, w is the width of the first frame of the captured video, h is the height of the first frame of the captured video, and the first frame is the frame captured by the shooting device at the initial shooting distance.

[0013] According to an embodiment of the present disclosure, when the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography push-track zoom process is ended, including: When the zoom ratio reaches or exceeds the maximum zoom ratio, the aerial photography zoom process ends.

[0014] According to an embodiment of the present disclosure, the calculating of the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate and the specified frame zoom ratio includes calculating the fixed acceleration a according to the following formula: ; Wherein, d is the initial shooting distance, fps is the specified frame rate, k is the specified frame zoom factor, is the maximum aerial zoom time.

[0015] According to an embodiment of the present disclosure, controlling the drone to fly away from the photographed object along the optical axis direction of the photographing device at a uniform acceleration according to the fixed acceleration includes: the drone flying at the following speed: To achieve the uniformly accelerated flight: = ; ; in, is the initial flight speed, and t is the aerial zoom time.

[0016] According to an embodiment of the present disclosure, when the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography push-track zoom process is ended, including: When the flight speed reaches or exceeds the maximum flight speed, the aerial photography zoom process is ended.

[0017] In a second aspect, an aerial photography push-track zoom system is provided in an embodiment of the present disclosure, comprising a main control unit, a flight control module, and a digital zoom module; the flight control module is arranged on a drone, the digital zoom module is arranged on a shooting device, and the main control unit is in communication connection with the flight control module and the digital zoom module; The main control unit is configured as follows: Acquire an initial shooting distance between a shooting device and a shooting object, a specified frame rate, a specified frame zoom ratio, and a progress determination threshold, wherein the shooting device is arranged on a drone, and the progress determination threshold includes any one of the following: a maximum aerial zoom time, a maximum zoom ratio, and a maximum flight speed; Calculate the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate, and the specified frame zoom factor; While controlling the shooting device to shoot video at the specified frame rate and controlling the digital zoom module to digitally zoom the shot video according to the specified frame zoom ratio, the flight control module is controlled to control the drone to fly away from the shooting object with uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, thereby realizing aerial photography push-track zoom.

[0018] According to an embodiment of the present disclosure, the main control unit includes a progress detection unit; The progress detection unit is configured to obtain a progress determination parameter corresponding to the progress determination threshold during the aerial photography zoom process, wherein the progress determination parameter includes any one of the aerial photography zoom time, zoom multiple, and flight speed; The main control unit is further configured to end the aerial photography tracking and zooming process when the progress determination parameter reaches or exceeds the corresponding progress determination threshold.

[0019] According to an embodiment of the present disclosure, the system further includes a coding output module, and the coding output module is arranged on the shooting device; The encoding output module is configured to encode and output the push-track zoom video after completing the aerial photography push-track zoom.

[0020] In a third aspect, an embodiment of the present disclosure provides a computer-readable storage medium on which computer instructions are stored. When the computer instructions are executed by a processor, the method described in any one of the first aspects is implemented.

[0021] In a fourth aspect, a computer program product is provided in an embodiment of the present disclosure, comprising computer instructions, which, when executed by a processor, implement the method as described in any one of the first aspects.

[0022] According to the technical solution provided by the embodiments of the present disclosure, the fixed acceleration of the drone is calculated based on the acquired initial shooting distance between the shooting device and the shooting object, the specified frame rate, the specified frame zoom factor, and the progress judgment threshold, the shooting device is set on the drone, and the progress judgment threshold includes any one of the following: maximum aerial photography zoom time, maximum zoom factor, maximum flight speed; while shooting a video at a specified frame rate and controlling the shooting device to digitally zoom the shot video according to the specified frame zoom factor, the drone is controlled to uniformly accelerate along the optical axis direction of the shooting device and fly away from the shooting object starting from the initial shooting distance according to the fixed acceleration, so as to realize aerial photography push-track zoom.

[0023] The present disclosure reduces the reliance on high-cost optical zoom lenses, thereby significantly reducing hardware costs. At the same time, it simplifies the flight control requirements of the drone, and can dynamically adjust the flight speed and zoom speed according to user needs, enabling more flexible digital zoom and matching flight speed control, thereby achieving automated management of push-track zoom, reducing the need for manual intervention, and improving shooting efficiency and consistency. It is particularly suitable for application scenarios that require repetitive or precise control, such as film shooting, advertising production, live broadcasts of sports events, and other fields. Through automated management and simplified flight control, the difficulty of operation is reduced, allowing even non-professionals to easily achieve high-quality push-track zoom shooting.

[0024] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Other features, objectives and advantages of the present disclosure will become more apparent through the following detailed description of non-limiting embodiments in conjunction with the accompanying drawings. In the accompanying drawings: Figure 1 A flowchart of an aerial photography push-track zoom method according to an embodiment of the present disclosure is shown; Figure 2 A schematic diagram showing a digital zoom process in an aerial photography push-track zoom method according to an embodiment of the present disclosure; Figure 3 A schematic diagram showing the relationship between a photographed object and a displayed image in an aerial photography push-track zoom method according to an embodiment of the present disclosure; Figure 4 A schematic diagram showing a comparison between a linear flight speed function and a nonlinear flight speed function in an embodiment of the present disclosure; Figure 5A flowchart of applying an aerial photography push-track zoom method to perform aerial photography push-track zoom according to an embodiment of the present disclosure is shown; Figure 6 A structural block diagram of an aerial photography push-track zoom system according to an embodiment of the present disclosure is shown; Figure 7 A schematic diagram showing the structure of a computer system suitable for implementing the method according to an embodiment of the present disclosure is shown. DETAILED DESCRIPTION

[0026] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. In addition, for the sake of clarity, parts not related to the description of the exemplary embodiments are omitted in the accompanying drawings.

[0027] In the present disclosure, it should be understood that terms such as "include" or "have" are intended to indicate the presence of features, numbers, steps, behaviors, components, parts, or a combination thereof disclosed in the present specification, and are not intended to exclude the possibility that one or more other features, numbers, steps, behaviors, components, parts, or a combination thereof exist or are added.

[0028] It should also be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present disclosure may be combined with each other. The present disclosure will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0029] In the present disclosure, if it involves operations of obtaining user information or user data or displaying user information or user data to others, the operations are all authorized and confirmed by the user, or actively selected by the user.

[0030] As mentioned above, existing technologies have achieved the control of camera optical zoom through autonomous movement of drones, thereby simplifying the implementation process of Hitchcock zoom. However, these solutions still have significant limitations. First, existing drones usually need to carry cameras equipped with optical zoom lenses, and the limited load space and strict hardware integration requirements of drones further raise the standards for the performance of optical zoom lenses, resulting in a significant increase in economic costs. Secondly, existing solutions often only support a limited number of zoom points and lack the ability to automatically control the Hitchcock zoom, which severely limits its flexibility and practicality. Therefore, a more efficient, economical and flexible solution is urgently needed to overcome these challenges.

[0031] According to the technical solution disclosed in the present invention, by obtaining the initial shooting distance, the specified frame rate, the specified frame zoom factor, and the progress judgment threshold between the shooting device and the shooting object, the shooting device is set on the unmanned aerial vehicle, and the progress judgment threshold includes any one of the following: maximum aerial zoom time, maximum zoom factor, maximum flight speed; the fixed acceleration of the unmanned aerial vehicle is calculated according to the initial shooting distance, the progress judgment threshold, the specified frame rate and the specified frame zoom factor; while shooting a video at the specified frame rate and controlling the shooting device to digitally zoom the shot video according to the specified frame zoom factor, the unmanned aerial vehicle is controlled to uniformly accelerate along the optical axis direction of the shooting device and fly away from the shooting object starting from the initial shooting distance according to the fixed acceleration, so as to realize aerial push-track zoom.

[0032] The present invention simplifies the flight control requirements of the drone, and can dynamically adjust the flight speed and zoom speed according to user needs, so as to achieve more flexible digital zoom and matching flight speed control, thereby realizing the automatic management of push-track zoom and reducing the need for manual intervention. In addition, through automatic management and simplified flight control, the difficulty of operation is reduced, so that even non-professionals can easily achieve high-quality push-track zoom shooting.

[0033] Figure 1 A flow chart of an aerial photography zooming method according to an embodiment of the present disclosure is shown.

[0034] like Figure 1 As shown, the method includes the following steps S101-S103: In step S101, an initial shooting distance between a shooting device and a shooting object, a designated frame rate, a designated frame zoom ratio, and a progress determination threshold are obtained.

[0035] According to an embodiment of the present disclosure, the shooting device is arranged on the drone. The shooting device is any device that can shoot a video, such as a camera, a video camera, a smart phone, a camera, etc. The shooting device can be fixed on the drone, or detachably connected to the drone, which is not limited by the present disclosure.

[0036] The above parameters (initial shooting distance, specified frame rate, specified frame zoom ratio, progress determination threshold) are obtained through user input.

[0037] According to an embodiment of the present disclosure, the progress determination threshold includes any one of the following: maximum aerial photography zoom time, maximum zoom ratio, and maximum flight speed.

[0038] In the present disclosure, the initial shooting distance is the distance between the shooting device and the shooting object when they are in the initial position, and the initial position is the position of the shooting device and the shooting object when they are in a relatively static state. It can be set as needed. Or it can be obtained by using sensors in actual scenes, such as laser ranging, ultrasonic waves, etc. It can also be calculated using a machine learning algorithm, such as estimation through an AI network.

[0039] The specified frame rate is the number of frames captured by the shooting device per second. The frame rate of the shooting device is closely related to its hardware performance (sensor, processor, memory) and software functions (frame rate setting, shooting mode), and can be selected according to actual needs (such as resolution, frame rate, shooting scene).

[0040] The specified frame zoom ratio refers to the ratio of picture enlargement achieved by adjusting the picture size in the video capture process, and is used to describe the degree of change from the original picture size to the target picture size.

[0041] According to an embodiment of the present disclosure, when the shooting device is controlled to perform digital zoom on the captured video according to the specified frame zoom ratio, each image frame of the captured video is enlarged by at least 2 pixels frame by frame. That is, each frame of the image is enlarged by at least two pixels, ensuring that each side of the captured image frame is indented by at least one pixel.

[0042] For example, at an initial shooting distance, a first image frame is obtained by shooting a subject using a shooting device, and the size of the first image frame includes a horizontal pixel number w and a vertical pixel number h. The first image frame is enlarged according to the execution frame zoom ratio k to obtain a second image frame adjacent to the first image frame, and the size of the second image frame is: a horizontal pixel number wk and a vertical pixel number hk, so the specified frame zoom ratio k needs to meet the following conditions: , so it can be inferred that , that is, when each image frame of the captured video is enlarged by at least 2 pixels frame by frame, the specified frame zoom ratio k satisfies the following formula: ; In other words, the specified frame zoom ratio is greater than or equal to the larger value of the value obtained by dividing 2 by the width of the first image frame plus 1 and the value obtained by dividing 2 by the height of the first image frame plus 1.

[0043] In step S102, the fixed acceleration of the drone is calculated according to the initial shooting distance, the progress determination threshold, the designated frame rate and the designated frame zoom factor.

[0044] In step S103, while shooting video at the specified frame rate and controlling the shooting device to digitally zoom the shot video according to the specified frame zoom ratio, the drone is controlled to fly away from the shooting object at a uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, thereby realizing aerial photography push-track zoom.

[0045] When the shooting device is controlled to digitally zoom the captured video according to the specified frame zoom ratio, if the size (horizontal pixel number and vertical pixel number) of the enlarged image frame is a decimal, a rounding operation (for example, rounding) needs to be performed.

[0046] In the present disclosure, digital zooming of a captured video includes: image magnification and image cropping, wherein the order of image magnification and image cropping can be swapped without affecting the final digital zoom result. Specifically, image magnification is to magnify the pixels of each frame of the captured video using the specified frame zoom ratio, and image cropping is to re-crop the size of each magnified frame of the image to the original image size (i.e., the size before magnification). The digital zoom of the captured video is achieved by image magnification and image cropping.

[0047] Figure 2 A schematic diagram of an image zooming process in an aerial photography push-track zooming method according to an embodiment of the present disclosure is shown.

[0048] like Figure 2 As shown in , when the enlarged image is re-cropped to the original image size, the position of the cropping frame is the central rectangular area of ​​the enlarged image. Assuming the original image size is , the size of the enlarged image is , taking the coordinates of the upper left vertex of the enlarged image as the origin, the coordinates of the upper left vertex of the cropped image are: , the size is .

[0049] The present invention adopts digital zoom instead of optical zoom, which reduces the dependence on high-cost optical zoom lenses, thereby significantly reducing hardware costs. At the same time, the introduction of digital zoom makes the zoom process more flexible, enabling a wider zoom range and more sophisticated zoom control.

[0050] According to an embodiment of the present disclosure, during the aerial photography push-track zoom process, a progress determination parameter corresponding to the progress determination threshold is obtained, and the progress determination parameter includes any one of the aerial photography zoom time, zoom factor, and flight speed; when the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography push-track zoom process is ended.

[0051] Therefore, the present disclosure realizes the automatic management of push-track zoom by combining digital zoom and drone flight control. This not only reduces the need for manual intervention, but also improves shooting efficiency and consistency, which is particularly suitable for application scenarios that require repetitive or precise control.

[0052] The present invention can also dynamically adjust the flight speed and zoom speed according to actual needs, so that the flight control speed can better match the speed of digital zoom, reducing the image jitter or instability caused by the mismatch between the flight speed and the zoom speed, thereby improving the shooting quality. And through automated management and simplified flight control, the difficulty of operation is reduced, so that even non-professionals can easily achieve high-quality push-track zoom shooting.

[0053] Furthermore, the maximum aerial photography zoom time is the minimum value between a first maximum aerial photography zoom time and a second maximum aerial photography zoom time, wherein the first maximum aerial photography zoom time is related to the maximum zoom factor, and the second maximum aerial photography zoom time is related to the maximum flight speed.

[0054] Specifically, the first maximum aerial zoom time With the maximum zoom ratio The relationship between them satisfies the following formula: ; The second maximum aerial zoom time With the maximum flight speed The relationship between them satisfies the following formula: ; Maximum aerial zoom time With the first maximum aerial zoom time and the second largest aerial zoom time The relationship between them satisfies the following formula: ; Wherein, d is the initial shooting distance, is the specified frame rate, and k is the specified frame scaling factor.

[0055] Further, the zoom factor is related to the specified frame scaling factor.

[0056] The relationship between the zoom factor n and the specified frame scaling factor k satisfies the following formula: , , ; Wherein, t is the aerial zoom time, is the zoom time of the large aerial photography, is the maximum flight speed, w is the width of the first image frame of the captured video, h is the height of the first image frame of the captured video, and the first image frame is the image frame captured by the shooting device at the initial shooting distance.

[0057] According to an embodiment of the present disclosure, when the zoom ratio reaches or exceeds the maximum zoom ratio, the aerial photography zoom process is terminated.

[0058] According to an embodiment of the present disclosure, the calculating of the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate and the specified frame zoom ratio includes calculating the fixed acceleration a according to the following formula: ; Wherein, d is the initial shooting distance, fps is the specified frame rate, k is the specified frame zoom factor, is the maximum aerial zoom time.

[0059] The method of controlling the drone to fly away from the photographed object along the optical axis direction of the photographing device at a uniform acceleration according to the fixed acceleration includes: the drone flying at a fixed speed according to the following To achieve the uniformly accelerated flight: = ; ; in, is the initial flight speed, and t is the aerial zoom time.

[0060] According to an embodiment of the present disclosure, when the aerial zoom time t reaches or exceeds the maximum aerial zoom time The aerial photography zoom process ends when the camera is turned on.

[0061] The following is a detailed description of calculating the fixed acceleration of the drone based on the initial shooting distance, the progress determination threshold, the specified frame rate and the specified frame zoom factor.

[0062] Figure 3 A schematic diagram showing the relationship between a photographed object and a displayed image in an aerial photography zoom method according to an embodiment of the present disclosure is shown, wherein the displayed image is an image displayed after the photographing device photographs the photographed object.

[0063] like Figure 3 As shown, assuming that the actual size of the object is h 实 , when the shooting distance is d and the focal length is set to f, the height in the shooting device (such as a camera) is h 显, in order to achieve track zoom, when the shooting distance is d+Δd and the focal length is set to f', that is, when the shooting device moves a specified distance Δd, the height of the object to be shot on the shooting device must remain at h 显 , then according to the principle of similar triangles we can conclude that: ; ; Therefore, the corresponding relationship between focal length and shooting distance can be deduced as: ; It is known that according to the definition of digital zoom multiples: , then according to the corresponding relationship between focal length and shooting distance, we can get: ; At the same time, the corresponding relationship between the digital zoom factor n and the specified frame zoom factor k, the aerial zoom time t, and the specified frame rate fps satisfies the following formula: ; Then we can get the initial shooting distance d and the specified distance The corresponding relationship between the specified frame zoom factor k, the specified frame rate fps and the aerial zoom time t satisfies the following formula: .

[0064] Then, by taking the derivative of the above formula with respect to time t, we can obtain the flight speed function of the drone: : ; That is, when the camera performs digital zoom with a zoom factor of k per frame, the flying speed of the drone along the optical axis of the camera is .

[0065] Then the flight speed function By taking the derivative of time t, we can get the acceleration function of the drone. : .

[0066] The inventors noticed that if the above flight speed function Or the acceleration function It is difficult to actually control the flight of a UAV. Because a UAV is a complex system, its flight control depends on the coordinated work of multiple subsystems, such as the power system, the rudder control system, the sensor network, and the flight control system. These subsystems interact with each other and jointly determine the flight state of the UAV. Therefore, nonlinear control of UAVs requires comprehensive consideration of multiple factors, including the dynamic characteristics of the UAV, external environmental interference, sensor accuracy, etc., which makes the design and implementation of control strategies too complicated.

[0067] Due to the limitations of the resolution of the camera or the maneuverability of the drone, the maximum zoom duration during aerial photography is relatively limited. In this case, by making a reasonable approximation of the acceleration function and controlling the flight of the drone based on the approximate acceleration value, the flight control execution process can be significantly simplified, making flight control more feasible and greatly reducing its complexity.

[0068] Therefore, by changing the above acceleration function After analysis, it can be seen that due to the specified frame zoom ratio k and the maximum aerial zoom time The value of is generally small, so the value of ln(k) is also small. The values ​​of d and fps have little effect on the final value. Therefore, the acceleration when t is the median of the maximum aerial zoom time can be taken as the fixed acceleration of the drone. , thus realizing the linear approximation of the nonlinear acceleration function, we can get: .

[0069] Then, the drone flies at the following speeds: To achieve uniform accelerated flight: = ; .

[0070] In the following, a specific embodiment is used to take the acceleration when t is the median of the maximum aerial zoom time as the fixed acceleration of the drone. The principle of the invention is described below. A person skilled in the art should understand that the frame zoom ratio k and the maximum aerial zoom time are specified. The specific values ​​of the initial shooting distance d and the frame rate fps are only exemplary and are not used as a technical means to limit the protection scope of the present disclosure.

[0071] Assume that at the initial shooting distance, the image size of the video is: 1920*1080, and the zoom is 4 pixels each time, then: ; set up =1.0037, d=10, fps=30, =10.

[0072] Substitute the above four parameters into the formula of the drone's flight speed function , and obtain the nonlinear flight speed function .

[0073] Substitute the above four parameters into the flight speed of the drone formula: , and obtain the linear flight speed function .

[0074] Figure 4 A schematic diagram showing a comparison between a linear flight speed function and a nonlinear flight speed function in an embodiment of the present disclosure is shown.

[0075] like Figure 4 As shown, since k≈1, the nonlinear flight speed function The curve is gentle, and ln(k) is very small. The d and fps coefficients have little effect on the final value. Generally, the maximum aerial zoom time is small, so it can be considered a linear flight speed function. With nonlinear flight speed function approximate.

[0076] In the present disclosure, the zoom-in and zoom-out effects in the aerial photography push-track zoom are achieved by utilizing the flight control of the drone and the digital zoom of the shooting device. The present disclosure can also perform an inverse transformation on the zoom-in and zoom-out video when the push-track zoom video is subsequently processed, thereby achieving the zoom-out effect of the shot video, enriching the shooting mode of the present disclosure, so that the video shot by the aerial photography push-track zoom of the present disclosure is not limited to the zoom-in and zoom-out effects.

[0077] Figure 5 A flow chart of applying an aerial photography push-track zoom method to perform aerial photography push-track zoom according to an embodiment of the present disclosure is shown.

[0078] like Figure 5 As shown, the aerial photography push-track zoom method can be applied in a main control unit, for example, an image processing module (CPU) of a shooting device, or a control unit independent of the shooting device and the drone.

[0079] First, the user inputs parameters (initial shooting distance between the shooting device and the object, designated frame rate, designated frame zoom factor, and progress determination threshold).

[0080] Then, the main control unit calculates the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate and the specified frame zoom factor.

[0081] Finally, the main control unit shoots video at the specified frame rate, controls the shooting device to digitally zoom the shot video according to the specified frame zoom ratio, and controls the drone to fly away from the shooting object at a uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance.

[0082] Among them, in the process of aerial photography zooming, progress detection is required, that is, obtaining the progress determination parameter corresponding to the progress determination threshold, and the progress determination parameter includes any one of the aerial photography zoom time, zoom factor, and flight speed; and when the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography zooming process is terminated. For example, when the aerial photography zoom time reaches or exceeds the maximum aerial photography zoom time, or when the zoom factor reaches or exceeds the maximum zoom factor, or when the flight speed reaches or exceeds the maximum flight speed, the aerial photography zooming process is terminated.

[0083] If the progress determination parameter does not reach the corresponding progress determination threshold, the digital zoom and the flight control of the UAV are continued until the progress determination parameter reaches or exceeds the corresponding progress determination threshold.

[0084] Figure 6 A structural block diagram of an aerial photography push-track zoom system according to an embodiment of the present disclosure is shown.

[0085] like Figure 6 As shown, the aerial photography push-track zoom system includes: a main control unit, a flight control module, and a digital zoom module; the flight control module is arranged on the drone, the digital zoom module is arranged on the shooting device, and the main control unit is communicatively connected with the flight control module and the digital zoom module.

[0086] The main control unit is configured as follows: Acquire an initial shooting distance between a shooting device and a shooting object, a specified frame rate, a specified frame zoom ratio, and a progress determination threshold, wherein the shooting device is arranged on a drone, and the progress determination threshold includes any one of the following: a maximum aerial zoom time, a maximum zoom ratio, and a maximum flight speed; Calculate the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate, and the specified frame zoom factor; While controlling the shooting device to shoot video at the specified frame rate and controlling the digital zoom module to digitally zoom the shot video according to the specified frame zoom ratio, the flight control module is controlled to control the drone to fly away from the shooting object with uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, thereby realizing aerial photography push-track zoom.

[0087] According to an embodiment of the present disclosure, the main control unit includes a progress detection unit; The progress detection unit is configured to obtain a progress determination parameter corresponding to the progress determination threshold during the aerial photography zoom process, wherein the progress determination parameter includes any one of the aerial photography zoom time, zoom multiple, and flight speed; The main control unit is further configured to end the aerial photography tracking and zooming process when the progress determination parameter reaches or exceeds the corresponding progress determination threshold.

[0088] According to an embodiment of the present disclosure, the system further includes a coding output module, and the coding output module is arranged on the shooting device; The encoding output module is configured to encode and output the push-track zoom video after completing the aerial photography push-track zoom.

[0089] The present invention simplifies the flight control requirements of drones, further reduces system complexity and implementation costs, and can be widely used in multiple fields such as film shooting, advertising production, and live broadcasts of sports events. In particular, it can provide richer and more dynamic visual effects in scenes that require complex lens movements.

[0090] Figure 7 A schematic diagram showing the structure of a computer system suitable for implementing the method according to an embodiment of the present disclosure is shown.

[0091] like Figure 7 As shown, the computer system includes a processing unit, which can execute various methods in the above-mentioned embodiments according to a program stored in a read-only memory (ROM) or a program loaded from a storage part into a random access memory (RAM). In the RAM, various programs and data required for the operation of the computer system are also stored. The processing unit, ROM and RAM are connected to each other through a bus. An input / output (I / O) interface is also connected to the bus.

[0092] The following components are connected to the I / O interface: an input part including a keyboard, a mouse, etc.; an output part including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker; a storage part including a hard disk, etc.; and a communication part including a network interface card such as a LAN card, a modem, etc. The communication part performs a communication process via a network such as the Internet. The drive is also connected to the I / O interface as needed. Removable media, such as disks, optical disks, magneto-optical disks, semiconductor memories, etc., are installed on the drive as needed so that the computer program read therefrom can be installed into the storage part as needed. Among them, the processing unit can be implemented as a processing unit such as a CPU, a GPU, a TPU, an FPGA, an NPU, etc.

[0093] In particular, according to an embodiment of the present disclosure, the method described above can be implemented as a computer software program. For example, an embodiment of the present disclosure includes a computer program product, which includes a computer program tangibly contained on a machine-readable medium, and the computer program includes a program code for executing the above method. In such an embodiment, the computer program can be downloaded and installed from a network through a communication part, and / or installed from a removable medium.

[0094] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architecture, functions and operations of the systems, methods and computer program products according to various embodiments of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0095] The units or modules involved in the embodiments described in the present disclosure may be implemented by software or programmable hardware. The units or modules described may also be set in a processor, and the names of these units or modules do not constitute limitations on the units or modules themselves in some cases.

[0096] As another aspect, the present disclosure further provides a computer-readable storage medium, which may be a computer-readable storage medium included in the electronic device or computer system in the above embodiment; or a computer-readable storage medium that exists independently and is not assembled into a device. The computer-readable storage medium stores one or more programs, and the programs are used by one or more processors to execute the method described in the present disclosure.

[0097] The above description is only a preferred embodiment of the present disclosure and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present disclosure is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present disclosure (but not limited to) by each other.

Claims

1. A method for zooming in aerial photography, characterized in that: include: Acquire an initial shooting distance between a shooting device and a shooting object, a specified frame rate, a specified frame zoom ratio, and a progress determination threshold, wherein the shooting device is arranged on a drone, and the progress determination threshold includes any one of the following: a maximum aerial zoom time, a maximum zoom ratio, and a maximum flight speed; Calculate the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate, and the specified frame zoom factor; While shooting video at the specified frame rate and controlling the shooting device to digitally zoom the shot video according to the specified frame zoom ratio, the drone is controlled to fly away from the shooting object with uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, thereby realizing aerial photography push-track zoom.

2. The aerial photography zoom method according to claim 1, characterized in that: Also includes: During the aerial photography zooming process, obtaining a progress determination parameter corresponding to the progress determination threshold, wherein the progress determination parameter includes any one of the aerial photography zooming time, zoom multiple, and flight speed; When the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography tracking and zooming process is ended.

3. The method according to claim 2, characterized in that: The maximum aerial photography zoom time is the minimum value between the first maximum aerial photography zoom time and the second maximum aerial photography zoom time, wherein the first maximum aerial photography zoom time is related to the maximum zoom factor, and the second maximum aerial photography zoom time is related to the maximum flight speed.

4. The method according to claim 3, characterized in that: The first maximum aerial zoom time With the maximum zoom ratio The relationship between them satisfies the following formula: ； The second maximum aerial zoom time With the maximum flight speed The relationship between them satisfies the following formula: ； Maximum aerial zoom time With the first maximum aerial zoom time and the second largest aerial zoom time The relationship between them satisfies the following formula: ； Wherein, d is the initial shooting distance, is the specified frame rate, and k is the specified frame scaling factor.

5. The method according to claim 4, characterized in that When the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography zoom process is ended, including: When the aerial zoom time t reaches or exceeds the maximum aerial zoom time The aerial photography zoom process ends.

6. The method according to claim 2, characterized in that The method further comprises: When the shooting device is controlled to perform digital zoom on the shot video according to the specified frame zoom ratio, each picture frame of the shot video is enlarged by at least 2 pixels frame by frame; The zoom factor is related to the specified frame magnification.

7. The method according to claim 6, characterized in that: When each picture frame of the captured video is enlarged by at least 2 pixels frame by frame, the specified frame zoom ratio k satisfies the following formula: ； The relationship between the zoom factor n and the specified frame scaling factor k satisfies the following formula: ， ； Wherein, t is the aerial zoom time, is the zoom time of the large aerial photography, is the maximum flight speed, w is the width of the first frame of the captured video, h is the height of the first frame of the captured video, and the first frame is the frame captured by the shooting device at the initial shooting distance.

8. The method according to claim 7, characterized in that When the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography zoom process is ended, including: When the zoom ratio reaches or exceeds the maximum zoom ratio, the aerial photography zoom process ends.

9. The method according to claim 2, characterized in that: The calculating the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate and the specified frame zoom factor includes calculating the fixed acceleration a according to the following formula: ； Wherein, d is the initial shooting distance, fps is the specified frame rate, k is the specified frame zoom factor, is the maximum aerial zoom time.

10. The method according to claim 9, characterized in that The method of controlling the drone to fly away from the photographed object along the optical axis direction of the photographing device at a uniform acceleration according to the fixed acceleration includes: the drone flying at a fixed speed according to the following To achieve the uniformly accelerated flight: = ； ； in, is the initial flight speed, and t is the aerial zoom time.

11. The method according to claim 10, characterized in that When the progress determination parameter reaches or exceeds the corresponding progress determination threshold, the aerial photography zoom process is ended, including: When the flight speed reaches or exceeds the maximum flight speed, the aerial photography zoom process is ended.

12. An aerial photography zoom system, characterized in that: It includes a main control unit, a flight control module, and a digital zoom module; the flight control module is arranged on the drone, the digital zoom module is arranged on the shooting device, and the main control unit is connected to the flight control module and the digital zoom module in communication; The main control unit is configured as follows: Acquire an initial shooting distance between a shooting device and a shooting object, a specified frame rate, a specified frame zoom ratio, and a progress determination threshold, wherein the shooting device is arranged on a drone, and the progress determination threshold includes any one of the following: a maximum aerial zoom time, a maximum zoom ratio, and a maximum flight speed; Calculate the fixed acceleration of the drone according to the initial shooting distance, the progress determination threshold, the specified frame rate, and the specified frame zoom factor; While controlling the shooting device to shoot video at the specified frame rate and controlling the digital zoom module to digitally zoom the shot video according to the specified frame zoom ratio, the flight control module is controlled to control the drone to fly away from the shooting object with uniform acceleration along the optical axis direction of the shooting device according to the fixed acceleration starting from the initial shooting distance, thereby realizing aerial photography push-track zoom.

13. The system according to claim 12, characterized in that The main control unit includes a progress detection unit; The progress detection unit is configured to obtain a progress determination parameter corresponding to the progress determination threshold during the aerial photography zoom process, wherein the progress determination parameter includes any one of the aerial photography zoom time, zoom multiple, and flight speed; The main control unit is further configured to end the aerial photography tracking and zooming process when the progress determination parameter reaches or exceeds the corresponding progress determination threshold.

14. The system according to claim 12, characterized in that The system further comprises a coding output module, wherein the coding output module is arranged on the shooting device; The encoding output module is configured to encode and output the push-track zoom video after completing the aerial photography push-track zoom.

15. A computer-readable storage medium having computer instructions stored thereon, characterized in that: When the computer instructions are executed by a processor, the method described in any one of claims 1 to 11 is implemented.

16. A computer program product, comprising computer instructions, which, when executed by a processor, implement the method according to any one of claims 1 to 11.

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