CN112514368B

CN112514368B - Image acquisition method, control device and movable platform

Info

Publication number: CN112514368B
Application number: CN202080004336.9A
Authority: CN
Inventors: 翁松伟; 宋玮
Original assignee: SZ DJI Technology Co Ltd
Current assignee: SZ DJI Technology Co Ltd
Priority date: 2020-03-11
Filing date: 2020-03-11
Publication date: 2022-08-19
Anticipated expiration: 2040-03-11
Also published as: CN112514368A; WO2021179225A1

Abstract

An image acquisition method, a control device and a movable platform. The method is used for acquiring a target image through a camera device installed on a cloud deck, and comprises the following steps: determining exposure parameters of the camera device, wherein the exposure parameters comprise exposure duration; determining rotation parameters of the holder, wherein the rotation parameters comprise a rotation direction, a rotation angle and a rotation speed of the holder, and the rotation speed is determined based on the exposure duration and the rotation angle; and controlling the holder to rotate based on the rotation parameters, and controlling the camera device to acquire images based on the exposure parameters so as to obtain the target image. In the exposure process, the cloud deck drives the camera device to have a certain movement speed, a target image with dynamic special effects such as residual images can be automatically acquired, the operation is simple, and images with dynamic special effects such as residual images can also be acquired for some static objects or objects with a low movement speed.

Description

Image acquisition method, control device and movable platform

Technical Field

The application relates to the technical field of image acquisition, in particular to an image acquisition method, a control device and a movable platform.

Background

In many shooting scenes, in order to reflect the dynamic effect of a shot target object, some images with special afterimage effects can be collected, so that the images are full of rhythm sense and rhythm sense. Generally, in order to acquire an image with a special afterimage effect, a photographer needs to manually control an image pickup device, such as controlling exposure parameters, moving the image pickup device, and the like, so as to satisfy specific conditions to obtain the image with the special afterimage effect, which is relatively complicated to operate and relatively high in shooting technical requirement for the photographer. Therefore, it is necessary to provide a method for acquiring an image with a special afterimage effect, which is simpler to operate.

Disclosure of Invention

In view of this, the present application provides an image capturing method, a control device and a movable platform.

According to a first aspect of the present application, there is provided an image capturing method for capturing a target image by a camera device mounted on a pan/tilt head, the method comprising:

determining exposure parameters of the camera device, wherein the exposure parameters comprise exposure duration;

determining rotation parameters of the holder, wherein the rotation parameters comprise a rotation direction, a rotation angle and a rotation speed of the holder, and the rotation speed is determined based on the exposure duration and the rotation angle;

and controlling the holder to rotate based on the rotation parameters, and controlling the camera device to acquire images based on the exposure parameters so as to obtain the target image.

According to a second aspect of the present application, there is provided a control apparatus, wherein the apparatus is configured to acquire a target image by an image capturing apparatus mounted on a pan/tilt head, the apparatus includes a processor, a memory, and a computer program stored in the memory, and the processor implements the following steps when executing the computer program:

According to a third aspect of the present application, there is provided a movable platform, characterized in that the movable platform comprises a pan/tilt head, an image pickup device mounted on the pan/tilt head, and the control device of the second aspect.

By applying the scheme provided by the application, exposure parameters such as exposure time of the camera device can be determined, the rotating angle and the rotating direction of the cradle head are determined, then the rotating speed of the cradle head is determined according to the rotating angle and the exposure time, the camera device is controlled to collect images through the determined exposure parameters, the motion of the cradle head is controlled through the determined rotating parameters, so that the exposure process is guaranteed, the cradle head drives the camera device to have a certain moving speed, target images with dynamic special effects such as residual images can be automatically collected, the operation is simple, and for some static or slow objects with the moving speed, images with the dynamic special effects such as the residual images can also be collected.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a flowchart of an image capturing method according to an embodiment of the present application.

Fig. 2 is a schematic view of an application scenario of the image capturing method according to an embodiment of the present application.

FIG. 3 is a diagram illustrating an effect of an afterimage effect influenced by a rotation direction according to an embodiment of the present application.

FIG. 4a is a schematic view of a movable platform according to an embodiment of the present application.

FIG. 4b is a schematic illustration of a user interface of a movable platform according to an embodiment of the present application.

Fig. 5 is a schematic diagram of an application scenario according to an embodiment of the present application.

Fig. 6 is a schematic diagram of a logical structure of a control device according to an embodiment of the present application.

Fig. 7 is a schematic diagram of a logical structure of a movable platform according to an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In order to reflect the dynamic effect of a shot target object, some images with a special afterimage effect can be collected, the afterimage has a trailing effect, the dynamic effect of the target object can be well reflected, and the images have rhythm effect and rhythm sense. In general, when capturing an image having a dynamic effect like a ghost image, there are certain requirements for the moving speed of a target object, the brightness of the environment, and the setting of exposure parameters. Taking the special afterimage image as an example, in order to obtain the special afterimage image, the target object is usually required to have a fast moving speed relative to the image capturing device, a slow shutter speed, and a long enough exposure time to obtain the special afterimage. This places high demands on the state of the target object, the environment, and the photographer. For example, if the target object is in a static state or has a slow movement speed, the photographer needs to move the camera device, so that the target object can obtain the special afterimage image at a fast speed relative to the camera device, and the photographer needs to control the camera device to move and set exposure parameters at the same time, so that the difficulty is high, the operation is complex, and the special afterimage image is difficult to acquire. Therefore, it is necessary to provide a simpler method for obtaining images with special effects similar to the afterimage special effect images.

Based on this, the present application provides an image capturing method, which may capture a target image through a camera device mounted on a pan/tilt head, where the target image may be an image with a certain special effect, for example, in some embodiments, the target image may be an image with a special afterimage effect, or an image with a dynamic effect similar to the afterimage special effect, for example, an image with a smearing effect formed at two ends of a target object, or an image with a special effect such as a ghost image of the target object. Specifically, as shown in fig. 1, the method may include the following steps:

s102, determining exposure parameters of the camera device, wherein the exposure parameters comprise exposure duration;

s104, determining rotation parameters of the holder, wherein the rotation parameters comprise a rotation direction, a rotation angle and a rotation speed of the holder, and the rotation speed is determined based on the exposure duration and the rotation angle;

and S106, controlling the holder to rotate based on the rotation parameters, and controlling the camera device to acquire images based on the exposure parameters so as to obtain the target image.

As shown in fig. 2, an application scenario schematic diagram of the image capturing method of the present application is shown, where a camera device may be installed on a pan/tilt, and the pan/tilt may drive the camera device to move. The holder can be a single-axis rotating holder and also can be a multi-axis rotating holder. The camera device can be a mobile phone, a camera and other terminal equipment arranged on the holder, and also can be a camera carried by the holder. In some embodiments, the image acquisition method of the present application may be executed by the control device, and after the control device determines the exposure parameter and the rotation parameter, the control device may control the pan/tilt head to rotate according to the determined rotation parameter, and control the camera device to perform image acquisition according to the determined exposure parameter, so as to obtain the target image. This controlling means can be integrated with the cloud platform, can also set up with cloud platform separation, for example set up in camera device, or partly integrated, partly set up with cloud platform separation with the cloud platform, and this application does not do specific restriction.

Generally, a target image with a certain special effect is acquired, and certain requirements are imposed on the motion state of a target object, the environment around the target object, the exposure parameters of a camera device and the like. Taking the special residual image as an example, to obtain the special residual image, the relative movement speed between the target object and the camera device needs to satisfy a certain condition, and the exposure duration needs to satisfy a certain condition, so that the special residual image can be acquired only if the conditions are met. Generally, when a target object with a fast moving speed is shot, the camera device can be kept still, and a slow shutter speed is set to ensure a long exposure time, so that a residual image can be obtained, and the situation is better controlled. However, for a target object which is still or has a slow moving speed, if the camera device is kept still, the afterimage special effect image cannot be obtained, so that it is difficult to control the camera device to move relative to the target object at a certain speed and control the exposure time, which depends on manual control.

The method and the device can determine the exposure parameters of the camera device and the rotation parameters of the holder based on the conditions of target image formation, wherein the exposure parameters comprise exposure duration, the rotation parameters of the holder comprise the rotation direction, the rotation angle and the rotation speed of the holder, and the rotation direction and the rotation angle of the holder can be determined according to the expected special effect of the target image. For example, to acquire an afterimage image, the rotation direction of the pan/tilt head determines the direction of the smear special effect smear, for example, whether the smear is located on the right or left of the target object, as shown in fig. 3, the smear special effect image is an afterimage of the captured moon, where the smear may be located on the left (a) or right (b) of the moon. The rotation angle of the pan-tilt determines the length of the tail. And to obtain a target image with special effects such as afterimages, the rotating time of the holder can be greater than or equal to the exposure time, so that the camera device is prevented from being in a static state in the exposure process, and the rotating speed can be determined according to the exposure time and the rotating angle.

After the exposure parameters of the camera device and the rotating speed of the cloud deck are determined, the cloud deck can be controlled to rotate according to the rotating parameters, and the camera device is controlled to collect images according to the exposure parameters to obtain target images. Wherein, the cloud platform rotates and camera device gathers the image and can go on simultaneously, also can go on successively, for example the cloud platform rotates earlier, then camera device carries out image acquisition again, as long as guarantee at least partly exposure in-process, the cloud platform is in the rotation state, and camera device has certain velocity of movement for the target object promptly.

According to the method and the device, the motion condition which needs to be met by the camera device relative to the target object is determined according to the formation condition of the target image, then the camera device is controlled to move through the holder, so that the camera device has a certain motion speed relative to the target object, and meanwhile, the camera device is controlled to carry out image acquisition according to the exposure parameters, so that the target image with dynamic special effects such as residual images can be automatically acquired, the operation is convenient, the control is easy, and for some static or slow target objects with motion speeds, images with dynamic special effects such as residual images can also be acquired.

In some embodiments, the target object may be determined prior to the target image acquisition, wherein the target object may be identified automatically or may be determined by user selection. For example, for some image capturing apparatuses, a user may select a capturing mode, such as person capturing, landscape capturing, moving object capturing, and the like, and thus a target object may be automatically recognized and determined according to the capturing mode selected by the user. For example, the user selects a person shooting mode, that is, a person captured by the camera device can be detected by a target detection algorithm to be a target object. Of course, in some embodiments, the target object may also be input by a user, and the control device for executing the image capturing method may include a human-computer interaction interface, where the human-computer interaction interface may present an image captured by the camera device, and the user may click the target object in the image through the human-computer interaction interface to select the target object. Certainly, in some embodiments, some interested objects in the image captured by the lens may be detected first, for example, objects in the captured image of a person, a vehicle, and the like may be detected, and a capture subject frame may be added and displayed to the user, so that the user may click the capture subject frame to select a target object, wherein after the user clicks the capture subject frame, a prompt message may be displayed on the interpersonal interaction interface to prompt the user whether to use the currently selected object as the captured target object, and after the user selects "OK", the target object may be determined, so that the user may be prevented from touching by mistake.

After the target object is determined, the exposure parameters of the image capturing device may be further determined, where the exposure parameters include an exposure time period. The exposure parameters may be input by a user through a user interface or may be automatically determined according to the brightness of the environment surrounding the target object.

Generally, the exposure degree of an image is determined by the size of an aperture for controlling the amount of light entering the CCD or CMOS photosensitive cell, the exposure time period for controlling the time period for which light enters the CCD or CMOS photosensitive cell, and the sensitivity (ISO) indicating the degree to which the CCD or CMOS photosensitive cell is sensitive to light. In some embodiments, the exposure parameters may be set by the user, for example, the user may input the exposure parameters, such as the exposure duration, the aperture parameter, and the like, through the human-computer interface. Certainly, the self-setting of the exposure parameter has a high requirement on the shooting technology of the user, and the operation is complex, and in order to simplify the operation of the user, in some embodiments, the exposure parameter may also be automatically determined according to the brightness of the surrounding environment of the target object, for example, an automatic exposure policy may be set in advance, and the exposure parameter may be determined according to the brightness of the surrounding environment of the target object and the set automatic exposure policy. In general, the exposure parameters and the brightness of the environment can satisfy apex (the Additive System of Photographic exposure) exposure equations, such as equation (1):

av + Tv ═ Sv + Bv formula (1)

Wherein: av represents the aperture size, and the value thereof represents a decrease in the amount of incident light by half for every 1 unit increase.

Tv represents the shutter speed, and the value of Tv increases by 1 unit, indicating that the amount of light entering decreases by half.

Sv represents the sensitivity (ISO) of the imaging device, and each 1 unit increase in the value indicates that the sensitivity of the camera to the same amount of light entering is doubled, and the brightness is doubled when the camera is seen on a photograph.

Bv represents the average luminance of the ambient light, which represents a doubling of the average luminance of the ambient light per 1 unit increase.

As can be seen from the exposure equation, when the sensitivity of the image pickup device or the ambient brightness increases, it is necessary to reduce the amount of light entering, that is, to reduce the sum on the left side of equation (1). Similarly, when the camera sensitivity or the ambient brightness is small, it is necessary to increase the amount of light entering, that is, to increase the sum on the left. Therefore, when the ambient light brightness Bv is measured, appropriate exposure parameters, i.e. aperture, shutter, ISO combination, can be calculated according to equation (1). Of course, in order to make the aperture, shutter, ISO, and ambient brightness satisfy the above formula (1), there are many combinations of the aperture, shutter, and ISO when the ambient brightness is determined. In determining the values of the aperture and the shutter, there are also an aperture priority exposure strategy and a shutter priority exposure strategy. The diaphragm priority exposure strategy refers to that the size of a diaphragm is determined in advance, then the shutter speed is determined according to the size of the diaphragm, ISO and ambient brightness, and the mode is convenient for controlling the depth of field of a picture. The shutter priority exposure strategy is to determine the shutter speed first and then set the aperture size according to the shutter speed, the ambient brightness and the ISO, and this method is suitable for capturing fast moving objects or occasions needing to show "dynamic" such as a stream of a gurgle, a galloping car or a night scene needing long exposure. Therefore, in some embodiments, in order to acquire a target image with a dynamic effect, the automatic exposure strategy may be set to a shutter-first exposure strategy.

As can be seen from the above exposure equation, to automatically determine the exposure parameters, the ambient brightness, commonly referred to as photometry, may be determined first. When determining the ambient brightness, an image including a target object acquired by the camera device, which is hereinafter referred to as a first image, may be acquired first, and then the brightness of the first image is determined according to the brightness of each pixel point in the first image, where the brightness of the first image may reflect the current ambient brightness, and the ambient brightness is higher, so that the acquired brightness of the first image is also higher. Suitable exposure parameters may then be determined for the camera device based on the brightness of the first image and the auto-exposure policy.

In some embodiments, when determining the brightness of the first image according to the brightness of each pixel point of the first image, a regional metering mode and a spot metering mode may be used, where the regional metering mode uses an average value of the brightness of each pixel point of the first image as a brightness value of the first image, that is, a brightness value of an environment, and the spot metering mode uses a weighted average value of the brightness of each pixel point of the first image as a brightness value of the first image. For example, when the brightness of the first image is calculated, the weights of the pixel points in each image region in the first image may be different, for example, the weight of the pixel point in the image region corresponding to the target object is larger, and the weights of the other regions are smaller, so as to accurately calculate the brightness of the surrounding environment of the target object.

Of course, in some embodiments, the brightness of the environment may be too high, and the calculated exposure duration may be short according to the set shutter-preferred exposure strategy, which requires that the rotational speed of the pan/tilt head is large, and in the actual usage scenario, the rotational speed of the pan/tilt head is limited. Therefore, in this case, the pan/tilt head cannot reach the rotational speed calculated according to the current exposure duration, and the target image cannot be acquired. Therefore, a threshold of the ambient brightness can be preset according to the maximum value of the rotating speed of the holder, and when the brightness of the first image obtained through calculation exceeds the preset threshold, prompt information that image acquisition cannot be completed is sent to a user, for example, "the current ambient brightness is too high, and a ghost image cannot be acquired" can be displayed in a user interaction interface to prompt the user.

After the exposure parameters are determined, the rotation parameters of the pan-tilt can be determined, and the rotation parameters of the pan-tilt generally include the rotation angle of the pan-tilt, the rotation direction of the pan-tilt, and the rotation speed of the pan-tilt. The rotation direction and the rotation angle determine the special effect of the target image, for example, the rotation direction determines a trailing direction of the afterimage special effect, and the rotation angle determines a trailing length of the afterimage special effect. Of course, in some embodiments, the rotational direction and angle of the pan/tilt head may also be determined according to preset default values, without manual input by the user.

Generally, a head may comprise one or more rotational axes about which the head may rotate, enabling movement in three-dimensional space. In some embodiments, the head may comprise three rotational axes, and the rotational direction may be a direction in which the head rotates about at least one of the three rotational axes. As shown in fig. 4a, which is a schematic view of a tripod head having three rotation axes, the tripod head may include a pitch axis 421, a roll axis 422 and a translation axis 423, and the tripod head may rotate around the axes, thereby moving left and right, up and down, and moving back and forth in a three-dimensional space.

The direction and angle input by the user may be the direction and angle of the rotation of the pan-tilt around each rotation axis, or the direction and angle of the overall movement of the pan-tilt relative to the target object. For example, in some embodiments, the direction input by the user may be a direction in which the pan/tilt head rotates around each axis, for example, an option of rotating around three axes may be displayed on the user interaction interface, so that the user can check one or more axes, and the rotation direction of the pan/tilt head is determined according to the check result of the user. The angle input by the user can also be the angle of the cradle head around each axial direction, and the user can input the angle corresponding to each axial direction after checking each axial direction.

In order to make the user intuitively know the final effect of the image corresponding to the input angle and direction, in some embodiments, the direction input by the user may be the overall movement direction of the pan/tilt head relative to the target object, such as the overall movement direction moving left or right relative to the target object, or the angle input by the user may be the movement angle of the pan/tilt head overall relative to the target object, such as the lower left angle of 45 degrees. The moving direction and the angle of the holder relative to the whole target object are the comprehensive result of the holder rotating a certain angle around each axial direction. Therefore, when the direction and the angle input by the user are the direction and the angle of the overall motion of the pan-tilt relative to the target object, the equipment executing the image acquisition method can automatically calculate which axes the pan-tilt needs to rotate around and the angle of the pan-tilt to rotate around the axes according to the direction and the angle input by the user, so that the pan-tilt can rotate according to the calculated rotating axes and rotating angles.

Since the target object may be stationary or moving, in some embodiments, when determining the rotation direction of the pan/tilt head, the movement direction of the target object may be determined first, and then the rotation direction of the pan/tilt head may be determined according to the movement direction of the target object. For example, the rotational direction of the pan/tilt head may be the same as the moving direction of the target object, or may be opposite to the moving direction of the target object, and may be set according to the desired effect of the target image.

For some novice users, the user may not be familiar with how reasonable the rotation angle is set, and the acquired image has a good effect. Therefore, in order to improve user experience and facilitate setting of rotation parameters by a user, in some embodiments, a preset recommended angle may be displayed in the user interaction interface, so that the user can set the angle according to the recommended angle.

When the user sets the parameters, in order to enable the user to know the special effect of the acquired image more clearly under the currently set parameters, in some examples, the corresponding preview effect can be displayed on the user interaction interface according to the direction and the angle input by the user, so that the user can adjust the input parameters according to the difference between the preview effect and the expected effect.

After the rotating direction and the rotating angle of the holder are determined, the rotating speed of the holder can be determined according to the rotating angle of the holder. Wherein, when the cloud platform rotates around a plurality of axles, the rotational speed of cloud platform includes the rotational speed around each axle. In some embodiments, in determining the rotation speed, the rotation duration may be determined according to the exposure duration, wherein the rotation duration may be greater than or equal to the exposure duration, and then the rotation speed may be determined according to the rotation angle and the rotation duration. Therefore, the shot target object and the camera device always move relatively in the exposure process, and the shooting effect of the target image is better.

In the shooting process, the camera shooting device is driven to move through the holder, so that the target object moves relative to the camera shooting device, and even if the target object is static, the shot image also has dynamic effects such as ghost shadow and the like. Similarly, similar special effects may be generated for some objects in the background portion of the target object. For example, when a vehicle is shot, in order to enable the shot vehicle to have a special afterimage effect, the cloud deck can be rotated to shoot the afterimage image, meanwhile, the special afterimage effect can be generated on the background behind the vehicle, such as a tree house, and the dynamic effect of the target object is not easily highlighted on the shooting scene with the complex background. In some embodiments, in order to obtain an image in which a target object has a special afterimage effect and a background portion retains a normal effect, the camera device may be controlled to perform image acquisition on the target object while the camera device is controlled by the pan-tilt to maintain a fixed posture, so as to obtain an image in which the target object and the background have no special effects such as afterimage, which is referred to as a second image. By the method, the image of the target object with the special residual image effect and the special residual image-free background effect can be obtained, and the dynamic effect of the target object can be better embodied.

To further explain the image capturing method of the present application, several specific examples are further explained below.

Generally, in order to capture an afterimage of a target object, the target object needs to have a fast moving speed and a slow shutter speed to extend an exposure time for acquiring the afterimage, which has high requirements on the state of the target object and a shooting technique of a photographer. For some target objects which are static and have a slow moving speed, if the camera device is kept still, the residual image cannot be acquired, but if a photographer needs to manually move the camera device, control the shutter speed and set exposure parameters, the difficulty is high.

The image acquisition method provided by the embodiment can well solve the problems, and an application scenario of the image acquisition method is described below.

In an embodiment, the image capturing method may be applied to a movable platform, such as a handheld shooting device shown in fig. 4a, the handheld shooting device includes a pan-tilt 42 and a control device (not shown), the pan-tilt 42 is provided with a camera 41, and image capturing is performed. The pan/tilt head includes three rotation axes, a pitch axis 421, a roll axis 422 and a translation axis 423, and the pan/tilt head can rotate around each axis to drive the camera 41 to rotate around the three rotation axes, so as to move left and right, up and down, and back and forth in a three-dimensional space. In addition, the handheld shooting device further includes a user interface 43, which can display the image captured by the camera 41, and meanwhile, the user can input an interactive instruction through the user interface to control the pan/tilt head 42 or the camera 41.

The user can select the afterimage mode or the normal photographing mode through the user interface. When the user selects the afterimage mode, the control device may automatically perform target detection according to the image acquired by the camera device, for example, detect an object of interest in the current picture as a target object to be photographed. The user interface 43 may mark the target object to be photographed with a photographing subject box, and the user may confirm the target object by clicking or select the target object by re-framing. After the shot target object is determined, the pan-tilt can acquire an image collected by the camera device, which is called a first image, and the brightness of the environment around the target object is predicted through the first image. The holder can determine the brightness of each pixel point of the collected first image, then calculate the weighted average value of the brightness of each pixel point as the brightness of the first image, wherein when the brightness of the first image is calculated, the weight of the pixel point of the image area corresponding to the target object is greater than the weight of the pixel point of other image areas. After the brightness of the first image is determined, the exposure parameters of the camera device can be determined according to the brightness of the first image and a preset shutter priority automatic exposure strategy, wherein the exposure parameters comprise exposure duration.

As shown in fig. 4b, the user interface displays a parameter setting interface, through which the user can select the rotation axis of the pan/tilt head, can select one or more of the pitch axis, the roll axis and the translation axis, and input an angle, and a recommended angle, such as a recommended angle of 40 ° -50 °, can be displayed in the interface for the user to refer to. The user may also select the default parameters without entering them, such as clicking on default values in the user interface. When the user selects the rotation axis and the input angle, the user interface can also display the preview effect of the image corresponding to the rotation axis and the input angle, so that the user can adjust the input parameters according to the preview effect.

The control device may determine the rotation duration of the cradle head according to the exposure duration, wherein the rotation duration of the cradle head is not less than the exposure duration, for example, may be slightly greater than the exposure duration, or equal to the exposure duration. After the rotation duration is determined, the control device can determine the rotation speed according to the angle and the rotation duration input by the user so as to control the holder to rotate according to the determined rotation direction, the determined rotation angle and the determined rotation speed, and control the shooting device to acquire an image of the target object according to the determined exposure parameters, so that the afterimage special effect image of the target object can be obtained.

In an embodiment, the image acquisition method can also be applied to terminal equipment provided with a camera device, wherein the terminal equipment provided with the camera device is arranged on a holder, and the terminal equipment can be a mobile phone, a tablet and the like. For example, as shown in fig. 2, the terminal device installed with the camera device is a mobile phone installed in a cradle head, and an application program is installed on the mobile phone for executing the image capturing method. The mobile phone and the holder can perform data transmission through wireless communication. The user can determine the target object through the interface of the application program and input parameters such as direction, angle and the like. The application program can determine exposure parameters and rotation parameters, send the rotation parameters to the cloud deck, and acquire images according to the determined exposure parameters by controlling the camera of the mobile phone and control the cloud deck to rotate according to the determined rotation parameters, so that the ghost special effect image of the target object can be obtained. For the specific determination process of the exposure parameter and the rotation parameter, reference may be made to the foregoing embodiments, and details are not repeated herein.

In one embodiment, the image capture method may be applied in part to the terminal device and the movable platform, i.e., a portion of the steps are performed by the movable platform and a portion of the steps are performed by an application on the terminal device. The terminal device can be a mobile phone, a tablet and the like, and the movable platform can be a handheld shooting device. For example, as shown in fig. 5, the handheld shooting device 52 may be connected to the mobile phone 51 through a physical interface or a wireless communication manner, and a user may view an image captured by the camera 522 through an interface of an application program on the mobile phone 51, determine a target object to be shot, input parameters such as a direction and an angle, and then send the parameters to the handheld shooting device 52. The exposure parameters may be determined by the handheld camera 52, or may be determined by the application program of the mobile phone 51 and then sent to the handheld camera 52. The handheld shooting device 52 includes a pan-tilt 521, a camera 522 and a control device (not shown), the control device can control the pan-tilt 521 to rotate according to the rotation parameters, and control the camera 522 to acquire an image according to the determined exposure parameters, so as to obtain a special afterimage image of the target object. For the specific determination process of the exposure parameter and the rotation parameter, reference may be made to the description of the foregoing embodiments, and details are not repeated here.

The present application further provides a control device, the device is used for collecting a target image through a camera device installed on a pan/tilt head, as shown in fig. 6, the device includes a processor 62, a memory 61 and a computer program stored in the memory, and the processor 62 implements the following steps when executing the computer program:

In some embodiments, the processor, when configured to determine the exposure parameters of the imaging device, comprises:

acquiring a first image acquired by the camera device;

determining the brightness of the first image based on the brightness of each pixel point in the first image;

and determining the exposure parameter based on the brightness of the first image and a preset automatic exposure strategy.

In some embodiments, the brightness of the first image is an average or weighted average of the brightness of each pixel in the first image.

In some embodiments, after determining the brightness of the first image based on the brightness of the pixel points in the first image, the processor is further configured to:

and if the brightness of the first image exceeds a preset threshold value, sending out prompt information which cannot finish image acquisition.

In some embodiments, the preset auto exposure strategy is a shutter-first auto exposure strategy.

In some embodiments, the rotation direction and the rotation angle are determined based on a direction and an angle input by a user through the user interface.

In certain embodiments, the processor is further configured to: and displaying the preview effect of the target image corresponding to the rotation direction and the rotation angle in the user interaction interface.

In certain embodiments, the processor is further configured to: and displaying a preset recommendation angle in the user interaction interface.

In some embodiments, the head comprises three axes of rotation, the direction of rotation comprising the direction of rotation of the head about at least one of the axes of rotation.

In some embodiments, the processor, when configured to determine the rotation speed based on the exposure time period and the rotation angle, comprises:

determining a rotation duration based on the exposure duration, wherein the rotation duration is greater than or equal to the exposure duration;

determining the rotation speed based on the rotation angle and the rotation time length.

In some embodiments, before controlling the image capturing device to capture an image, the processor is further configured to: and determining a shot target object.

In some embodiments, if the target object is a moving target, the processor is configured to determine a rotation parameter of the pan/tilt head, and includes:

determining a motion direction of the target object;

and determining the rotation direction of the holder based on the motion direction of the target object.

In certain embodiments, the processor is further configured to:

controlling the camera device to acquire an image of the target object while keeping a fixed posture through the holder to obtain a second image;

and fusing an image area corresponding to the target object in the target image with an image area corresponding to the background of the target object in the second image to obtain a third image.

The specific process of image acquisition may refer to the description in the above method, and is not described herein again.

As shown in fig. 7, the movable platform includes a cradle head 72, the cradle head 72 is provided with a camera 71, and the movable platform further includes a control device 73, where the control device 73 may refer to the description in the foregoing embodiments, and is not described herein again. The movable platform of this application embodiment includes hand-held type shooting equipment, unmanned aerial vehicle, unmanned car.

Accordingly, an embodiment of the present specification further provides a computer storage medium, where a program is stored, and when the program is executed by a processor, the method for acquiring an image in any of the above embodiments is implemented.

Embodiments of the present description may take the form of a computer program product embodied on one or more storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having program code embodied therein. Computer-usable storage media include permanent and non-permanent, removable and non-removable media, and information storage may be implemented by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of the storage medium of the computer include, but are not limited to: phase change memory (PRAM), Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technologies, compact disc read only memory (CD-ROM), Digital Versatile Discs (DVD) or other optical storage, magnetic tape storage or other magnetic storage devices, or any other non-transmission medium, may be used to store information that may be accessed by a computing device.

For the device embodiments, since they substantially correspond to the method embodiments, reference may be made to the partial description of the method embodiments for relevant points. The above-described embodiments of the apparatus are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement without inventive effort.

It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The method and apparatus provided by the embodiments of the present invention are described in detail above, and the principle and the embodiments of the present invention are explained in detail herein by using specific examples, and the description of the embodiments is only used to help understanding the method and the core idea of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed, and in summary, the content of the present specification should not be construed as a limitation to the present invention.

Claims

1. An image acquisition method is characterized in that the method is used for acquiring a target image with a dynamic special effect through a camera device arranged on a holder, and the method comprises the following steps:

determining rotation parameters of the holder, wherein the rotation parameters comprise a rotation direction, a rotation angle and a rotation speed of the holder, and the rotation speed is determined based on the following modes: determining a rotation duration based on the exposure duration, wherein the rotation duration is greater than or equal to the exposure duration, and determining the rotation speed based on the rotation angle and the rotation duration;

2. The image acquisition method according to claim 1, wherein determining exposure parameters of the camera device comprises:

acquiring a first image acquired by the camera device;

3. The image acquisition method according to claim 2, wherein the brightness of the first image is an average value or a weighted average value of the brightness of each pixel point in the first image.

4. The image capturing method according to claim 2, wherein after determining the brightness of the first image based on the brightness of each pixel in the first image, the method further comprises:

5. The image capturing method as claimed in claim 2, wherein the preset auto exposure strategy is a shutter-first auto exposure strategy.

6. The image capturing method according to claim 1, wherein the rotation direction and the rotation angle are determined based on a direction and an angle input by a user through a user interface.

7. The image acquisition method according to claim 6, further comprising: and displaying the preview effect of the target image corresponding to the rotation direction and the rotation angle in the user interaction interface.

8. The image acquisition method according to claim 6, characterized in that it further comprises: and displaying a preset recommendation angle in the user interaction interface.

9. The image capturing method according to claim 1, wherein the pan/tilt head includes three rotational axes, and the rotational direction includes a direction in which the pan/tilt head rotates around at least one of the rotational axes.

10. The image capturing method according to any one of claims 1 to 9, wherein before controlling the imaging device to capture the image, the method further includes: and determining a shot target object.

11. The image capturing method of claim 10, wherein if the target object is a moving target, the determining the rotational parameter of the pan/tilt head comprises:

determining a motion direction of the target object;

12. The image capturing method according to claim 10, further comprising:

13. The image acquisition method according to claim 1, wherein the target image comprises a ghost special effect image.

14. A control apparatus for capturing a target image having a specific special effect by an image capturing device mounted on a pan/tilt head, the apparatus comprising a processor and a memory storing a computer program, the processor implementing the following steps when executing the computer program:

15. The control device of claim 14, wherein the processor, when determining the exposure parameters of the imaging device, comprises:

acquiring a first image acquired by the camera device;

16. The control device according to claim 15, wherein the luminance of the first image is an average or a weighted average of the luminance of each pixel in the first image.

17. The control device of claim 15, wherein the processor, after determining the brightness of the first image based on the brightness of the pixels in the first image, is further configured to:

18. The control device of claim 15, wherein the preset auto-exposure strategy is a shutter-first auto-exposure strategy.

19. The control device of claim 14, wherein the rotational direction and the rotational angle are determined based on a direction and an angle input by a user through a user interface.

20. The control device of claim 19, wherein the processor is further configured to: and displaying the preview effect of the target image corresponding to the rotation direction and the rotation angle in the user interaction interface.

21. The control device of claim 19, wherein the processor is further configured to: and displaying a preset recommendation angle in the user interaction interface.

22. The control device of claim 14, wherein the pan/tilt head comprises three rotational axes, and the rotational direction comprises a direction in which the pan/tilt head rotates about at least one of the rotational axes.

23. The control device according to any one of claims 14 to 22, wherein the processor is configured to, before controlling the camera device to perform image acquisition, further configured to: and determining a shot target object.

24. The control device of claim 23, wherein if the target object is a moving target, the processor is configured to determine a rotation parameter of the pan/tilt head, and comprises:

determining a direction of motion of the target object;

25. The control device of claim 23, wherein the processor is further configured to:

26. A movable platform, characterized in that it comprises a head, a camera device mounted to the head and a control device according to any one of claims 14-25.