WO2018228352A1

WO2018228352A1 - Synchronous exposure method and apparatus and terminal device

Info

Publication number: WO2018228352A1
Application number: PCT/CN2018/090743
Authority: WO
Inventors: 崔永太
Original assignee: 深圳市瑞立视多媒体科技有限公司
Priority date: 2017-06-12
Filing date: 2018-06-12
Publication date: 2018-12-20
Also published as: CN107231533B; CN107231533A

Abstract

A synchronous exposure method and apparatus, and a terminal device, applied to a multi-camera system, the method comprising: adjusting the exposure time of cameras in the multi-camera system, so that all cameras in the multi-camera system expose synchronously while collecting images; obtaining synchronous identification information, so that a corresponding camera in the multi-camera system associates the synchronous identification information with images to be synchronized of each camera in the multi-camera system so that the images to be synchronized of each camera have the same synchronous identification information, the images to be synchronized of each camera being images collected thereby respectively during synchronous exposure by all cameras in the multi-camera system. According to the present solution, the image collected by each camera respectively during the synchronous exposure by all cameras is added to synchronous identification information so as to solve the problem of synchronously exposed images being identified inaccurately.

Description

Synchronous exposure method, device and terminal device

Technical field

The invention belongs to the technical field of multi-camera systems, and in particular relates to a synchronous exposure method, device and terminal device.

Background technique

The multi-camera system is a system based on the principle of computer vision, which combines multiple cameras, light sources, storage devices, etc., and is commonly used in 3D reconstruction, motion capture, multi-view video, and the like. For example, optical motion capture is a technique for capturing motion by monitoring and tracking target feature points from different angles by multiple high-speed cameras based on the principle of computer vision. For any point in space, as long as it is seen by both cameras at the same time, the position of the point in space at this moment can be determined. When the camera continuously shoots at a high enough rate, the image sequence can be obtained. The trajectory of the point, if a plurality of points are marked on one object, and the object is photographed simultaneously by multiple cameras, the motion trajectory of the object can be obtained. This also requires exposure alignment when multiple cameras participating in the capture capture each frame of the image.

At present, each camera in the multi-camera system will immediately send the server after acquiring the image, and the server processes the image acquired at the same time as the image of the synchronous exposure. However, when the models of the cameras in the multi-camera system are different, the time taken for the cameras of different models to acquire one frame of image is different, so it will be inaccurate for the server to take the images acquired at the same time as the images of the synchronous exposure.

technical problem

In view of this, the present invention provides a synchronous exposure method, apparatus, and terminal device that solve the problem of inaccuracy in recognizing an image of synchronous exposure.

Technical solution

In a first aspect of the invention, a method of simultaneous exposure is provided for use in a multi-camera system, the method comprising:

Adjusting an exposure time of a camera in the multi-camera system such that all cameras in the multi-camera system acquire images synchronously;

Acquiring synchronization identification information, so that the synchronization identification information is associated with the image to be synchronized of each camera in the multi-camera system, such that the images to be synchronized of each camera have the same synchronization identification information, and each camera is to be The synchronized image is an image acquired by each camera separately when all cameras in the multi-camera system are simultaneously exposed.

According to a second aspect of the present invention, there is provided a synchronous exposure apparatus for use in a multi-camera system, the apparatus comprising:

a synchronization module, configured to adjust an exposure time of the camera in the multi-camera system, such that all cameras in the multi-camera system simultaneously perform exposure when acquiring images;

An association module, configured to acquire synchronization identification information, so that the synchronization identification information is associated with an image to be synchronized of each camera in the multi-camera system, such that images to be synchronized of each camera have the same synchronization identification information, The image to be synchronized of each camera is an image separately acquired by each camera when all the cameras in the multi-camera system are simultaneously exposed.

According to a third aspect of the present invention, a terminal device is provided, the terminal device being applied to a multi-camera system, the terminal device comprising a memory, a processor, and a computer stored in the memory and operable on the processor a program that, when the processor executes the computer program, implements the steps of the method provided by the first aspect above.

A fourth aspect of the invention provides a computer readable storage medium storing a computer program, the computer program being executed by one or more processors to implement the The steps of the method.

Beneficial effect

The beneficial effects of the present invention over the prior art are:

The technical solution provided by the present invention firstly needs to adjust the synchronous exposure when the camera captures an image in the multi-camera system, and acquires synchronization identification information based on the multi-camera synchronous exposure, and the synchronization identification information can be combined with the multi-camera system. Correlating the images to be synchronized of each of the cameras, or compressing the synchronization identification information into the image data to be synchronized of each camera in the multi-camera system, so that all images of the synchronized exposure have the same synchronization identification information, even if In a multi-camera system, each camera captures an image and sends it to the server for a different time, and does not cause inaccuracies in identifying the simultaneously exposed image.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the embodiments or the description of the prior art will be briefly described below. It is obvious that the drawings in the following description are only the present invention. For some embodiments, other drawings may be obtained from those of ordinary skill in the art in light of the inventive workability.

1 is a schematic flow chart of a first embodiment of a synchronous exposure method provided by the present invention;

2 is a schematic flow chart of still another embodiment of a synchronous exposure method provided by the present invention;

3 is a schematic flow chart of an embodiment of step S101 in the first embodiment provided by the present invention;

4 is a schematic flow chart of still another embodiment of step S101 in the first embodiment provided by the present invention;

5 is a schematic flow chart of still another embodiment of step S101 in the first embodiment provided by the present invention;

6 is a schematic flow chart of still another embodiment of step S101 in the first embodiment provided by the present invention;

7 is a schematic flow chart of still another embodiment of step S101 in the first embodiment provided by the present invention;

8 is a schematic flow chart of still another embodiment of step S101 in the first embodiment provided by the present invention;

9 is a schematic flow chart of still another embodiment of step S101 in the first embodiment provided by the present invention;

Figure 10 is a schematic block diagram of an embodiment of a synchronous exposure apparatus provided by the present invention;

11 is a schematic block diagram of an embodiment of a terminal device provided by the present invention.

Embodiments of the invention

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the described embodiments are a part of the embodiments of the present invention, but not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Before describing a specific embodiment of an embodiment of the present invention, the working mode of the multi-camera system is first analyzed.

Typically, multi-camera systems are used for 3D reconstruction, motion capture, multi-view video, and the like. This requires multiple cameras participating in the multi-camera system to capture the exposure alignment of each frame of the image; at the same time, because the multi-camera system continuously shoots at a higher rate, then the image sequence of the higher-speed continuous shooting is sent to the server or Data processing systems, servers or data processing systems need to identify synchronized exposure images from a large number of images received, in the prior art where the server identifies synchronized exposure images based on the time of receipt. However, in practical applications, for a variety of reasons, cameras in multi-camera systems are not guaranteed to have the same model, and different models of cameras have synchronized exposure, but the time elapsed since acquiring one frame of image It may be different, the camera in the multi-camera system will send the image to the server or data processing system immediately after the image is acquired, so that the image acquired by the synchronous exposure will not be sent to the server or image processing system at the same time, if the server or image processing It is obviously inaccurate that the system still recognizes the image of the synchronized exposure based on the time of reception.

In order to solve this problem, a synchronous exposure method, apparatus, and terminal device of the present invention have been proposed.

Hereinafter, a detailed description will be made by way of specific examples.

Please refer to FIG. 1. FIG. 1 is a schematic flow chart of a first embodiment of a synchronous exposure method according to the present invention. The synchronous exposure method shown in FIG. 1 may include the following steps:

Step S101, adjusting an exposure time of a camera in the multi-camera system such that all cameras in the multi-camera system simultaneously expose images when acquiring images.

In the embodiment of the present invention, the application range of the multi-camera system determines that the image captured by the multi-camera system should be an image of synchronous exposure, so it is first necessary to adjust the camera in the multi-camera system so that all cameras in the multi-camera system are synchronized when acquiring images. exposure. In order to ensure simultaneous exposure when all cameras in the multi-camera system capture images, one of the multi-camera systems can be selected as the main camera, and the other cameras as the slave cameras are adjusted according to the difference between the exposure time of the main camera and the slave camera. The exposure time of the cameras in the camera system causes simultaneous exposure of all cameras in the multi-camera system when capturing images.

Step S102, acquiring synchronization identification information, so that the synchronization identification information is associated with the image to be synchronized of each camera in the multi-camera system, so that the images to be synchronized of each camera have the same synchronization identification information, each of which The image to be synchronized of the camera is an image respectively acquired by each camera when all the cameras in the multi-camera system are simultaneously exposed.

In an embodiment of the present invention, after implementing simultaneous exposure of all cameras in a multi-camera system, as previously described, multi-camera systems often require multiple cameras to continuously capture at a sufficiently high rate to obtain motion trajectories of objects from a sequence of images. Etc., so the server or data processing system will receive a sequence of images sent by multiple cameras at a high enough rate. If there are different models of cameras in the multi-camera system, even if all the cameras have the same exposure time, the timing at which each camera sends the captured images to the server is different, then the server still judges whether the images are synchronized or not according to the time when the images are acquired. Obviously it is not accurate. At this time, we consider that the synchronization identification information can be acquired, and the synchronization identification information is notified to the corresponding camera in the multi-camera system. As such, all cameras in the multi-camera system can associate the synchronization identification information with the image to be synchronized, for example, the camera in the multi-camera system can add synchronization identification information to the image to be synchronized, or compress the synchronization identification information. The synchronized image data is entered so that the simultaneously exposed images (ie, the images to be synchronized) have the same synchronization identification information. In this way, the server or the data processing system can determine, according to the synchronization identification information, which of the plurality of images received are images respectively acquired by each camera when all the cameras in the multi-camera system are simultaneously exposed. It should be noted that the synchronization identification information may be an image frame number of an image to be synchronized in the main camera, or may be randomly generated information, for example, composed of different characters or different numbers.

It should be noted that the synchronization identifier information is obtained in multiple manners, for example, by using an external control device, and then the synchronization identifier information may be sent to each camera in the multi-camera system after acquiring the synchronization identifier information, so as to facilitate Each camera can associate the synchronization identification information with the image to be synchronized such that the synchronously exposed images have the same synchronization identification information; and, for example, the synchronization identification information is generated by one of the cameras, then the synchronization identification information is acquired at this time. Thereafter, the synchronization identification information can be transmitted to the remaining cameras in the multi-camera system such that the images respectively acquired by each camera have the same identification information when all cameras in the multi-camera system are simultaneously exposed.

In the embodiment of the present invention, the synchronization identification information is sent to the corresponding camera by synchronously exposing all the cameras in the multi-camera system, and then each camera associates the synchronization identification information with the image to be synchronized so that all the images exposed by the camera at the same time have the image. Same synchronization identification information. In this way, the server can determine whether the acquired images sent by the respective cameras are synchronized according to the synchronization identification information in the received captured image.

2 is a schematic flow chart of still another embodiment of the synchronous exposure method provided by the present invention. The synchronous exposure method shown in FIG. 2 may include the following steps:

In step S201, the exposure time of the camera in the multi-camera system is adjusted such that all the cameras in the multi-camera system simultaneously perform exposure when acquiring images.

Step S202: Acquire an image frame number of an image of any one of the cameras to be synchronized in the multi-camera system, and use the image frame number as the synchronization identification information.

In the embodiment of the present invention, the image frame number of the image to be synchronized of a certain camera may also be used as the synchronization identification information, and the image to be synchronized is an image separately acquired by each camera when all the cameras in the multi-camera system are simultaneously exposed. The selected camera can be the same camera as the main camera, or it can be a different camera. The image frame number of the image to be synchronized of the camera is obtained as the synchronization identification information, which can be selected according to the actual application scenario. .

Step S203, sending an image frame number of the image to be synchronized to a corresponding camera in the multi-camera system, so that the camera in the multi-camera system adjusts the image to be synchronized according to the received image frame number. Image frame number.

In an embodiment of the present invention, after acquiring an image frame number of a to-be-synchronized image of a certain camera, the image frame number is sent to a corresponding camera in the multi-camera system, and the camera in the multi-camera system is receiving The image frame number of the image to be synchronized is adjusted after the image frame number, so that the images of the synchronous exposure in the multi-camera system have the same image frame number.

When adjusting the frame number of the image to be synchronized, each camera in the multi-camera system compares the image frame number as the synchronization identification information with the frame number of the image to be synchronized, and determines whether adjustment is needed, if necessary, The frame number of the image to be synchronized itself is adjusted to the image frame number as the synchronization identification information.

The embodiment of the present invention obtains the image frame number of the image to be synchronized of one of the cameras in the multi-camera system as the synchronization identification information, and the other cameras adjust the image frame number of the image to be synchronized into the image to be synchronized in the image to be synchronized as the synchronization identification information. The image frame number is such that the images exposed by all the cameras in the multi-camera system at the same time have the same image frame number, so that the server can judge whether the acquired images sent by the respective cameras are synchronized according to the image frame number in the received captured image.

As another embodiment of the present invention, after the image to be synchronized is associated with the synchronization identification information, the method may further include:

Generating synchronization identification subsequence information according to the synchronization identification information, so that each camera in the multi-camera system sequentially associates the synchronization identification sub-sequence information with an image sequence after the image to be synchronized such that the image after the image to be synchronized The sequences in turn have the same synchronization identification subsequence information.

In the embodiment of the present invention, the multi-camera system does not perform a synchronous exposure before each frame of image is taken, that is, a synchronous exposure may be performed at a certain time interval, and then we may consider adding synchronization in the image of the synchronous exposure. After the identification information, the synchronization identification sub-sequence information is generated according to the synchronization identification information, and the synchronization identification sub-sequence information is added to the image sequence captured after the synchronously exposed image. When the synchronous exposure is implemented again, the synchronization identification information is regenerated, and after the synchronization exposure again. The sequence of captured images is sequentially added to the synchronization identification subsequence information.

Specifically, by way of example, we assume that the synchronization identification information added in the image to be synchronized during the first synchronous exposure is eight-digit information 00010000, and the synchronization identification information added in the image to be synchronized in the second synchronization exposure is 00020000, and so on, the first four bits represent the sequence of images to be synchronized during simultaneous exposure. Multiple sets of images may be taken between each synchronized exposure, and multiple image sequences captured between the image to be synchronized during the first simultaneous exposure and the image to be synchronized during the second simultaneous exposure may use 00010001, 00010002, 00010003... ... indicates that, similarly, the image sequence between the image to be synchronized and the image to be synchronized during the third simultaneous exposure may be represented by 00020001, 00020002, 00020003, etc., and so on, and the last four digits are indicated. A sequence of images between images to be synchronized during two simultaneous exposures. It should be noted that the example is for illustrative purposes only and is not intended to limit the embodiments of the present invention. Different synchronization identification information sequences may be evolved according to different synchronization identification information.

It should be noted that, if the synchronization identifier subsequence is generated by one of the cameras, then after the synchronization identifier subsequence is obtained, the synchronization identifier subsequence may be sent to the corresponding camera in the multi camera system. Thus, all cameras can associate the acquired synchronization identification subsequence with the image after the image to be synchronized, such that images acquired after multiple cameras to be synchronized images (synchronized exposure images) in the multi-camera system also have the same identification information.

In the embodiment of the present invention, the images acquired after the plurality of cameras to be synchronized images can also have the same synchronization identifier subsequence information by synchronizing the identifier subsequence information, so that the server or the data processing system can obtain the synchronization identification information when receiving a large number of images. Or synchronizing the sub-sequence information to know which images can be used as images for simultaneous exposure.

As an embodiment in step S101, the cameras in the multi-camera system can be adjusted in such a manner that all of the cameras in the multi-camera system are simultaneously exposed when images are captured.

Step S301, one of the multi-camera systems is selected as a main camera, and a camera other than the main camera is used as a slave camera.

Step S302, acquiring a difference between the exposure time of the main camera and the slave camera;

Step S303, adjusting an exposure time of the camera in the multi-camera system according to a difference between the exposure time of the main camera and the slave camera such that all cameras in the multi-camera system acquire images synchronously.

In the embodiment of the present invention, in order to ensure that all cameras in the multi-camera system acquire images synchronously, one of the cameras may be selected as the main camera from the multi-camera system, and the other cameras as the slave cameras respectively acquire the main camera and the camera. The difference in the exposure time of the camera is due to the existence of this difference, which will result in the camera not being able to achieve simultaneous exposure in a multi-camera system. Therefore, the exposure time of each camera can be adjusted according to this difference so that all cameras are simultaneously exposed.

It should be noted that the above is merely an example and is not intended to limit the present invention. In practice, there are many methods for realizing multi-camera synchronous exposure.

As previously mentioned, embodiments of the present invention require that the exposure time of the cameras in the multi-camera system be adjusted such that all cameras in the multi-camera system are simultaneously exposed when capturing images. Some examples have been made in steps S301 to S303. As still another embodiment of the present invention, synchronization exposure may be achieved when images are acquired by a plurality of cameras in a multi-camera system by other methods. It can be understood that the purpose of adjusting the exposure time can be achieved by adjusting the frame length of the image captured by the camera.

First analyze the cause of the unsynchronized exposure of each camera in a multi-camera system.

Generally, there is a 64-bit hardware timer built by the FPGA inside the camera, that is, hardware time code. The hardware time code is the minimum timing unit of the camera sensor input clock (MCLK) crystal oscillation period, that is, every crystal clock cycle The value of the hardware time code is automatically incremented by 1.

In one case, when all cameras have the same initial settings (that is, the hardware and software configurations are the same), the hardware time codes passed by all the cameras to capture one frame of image are the same. In another case, when the image sensor models of all cameras are different (and other hardware and software configurations are the same), the image resolution of the camera is different at this time, but the hardware time code of all the cameras capturing one frame of image is still the same. of. However, in practice, the oscillation period of the actual crystal oscillator of the camera is constantly changing due to some factors such as temperature and humidity. That is to say, the crystal oscillation period of each camera is not necessarily equal, so the time elapsed when each camera captures one frame of images in a multi-camera system is not necessarily the same, which is the root cause of camera exposure unsynchronization in a multi-camera system.

Of course, in actual use, it is also found that external environmental factors such as network transmission delay and network instability may cause multiple cameras to acquire images without being completely synchronized.

In order to solve the problem that the camera exposure is not synchronized in the multi-camera system, we will solve the problem by a detailed description of specific embodiments. One of the embodiments may implement simultaneous exposure of a plurality of cameras in a multi-camera system by externally controlling a multi-camera system, and the control device may control simultaneous exposure of a plurality of cameras in the multi-camera system. The steps in the above embodiments may also be performed by The control device is completed, and the specific implementation steps are as follows:

Referring to FIG. 4, FIG. 4 is a schematic flowchart of still another embodiment of step S101 in the first embodiment of the present invention. The method for synchronously exposing the plurality of cameras as shown in FIG. 4 may include the following steps:

Step S401, after receiving the instruction of synchronous exposure, acquiring an initial hardware time code of each camera in the multi-camera system to obtain a plurality of initial hardware time codes.

The method of the embodiments of the present invention can be integrated into a control device for application to a multi-camera system, and an embodiment of the present invention is for simultaneously taking photos of multiple cameras in a multi-camera system. The instructions for simultaneous exposure can be issued by one of the cameras in the multi-camera system or by the external control device itself. The synchronous exposure command may be a timer inside the control device or the camera, and a synchronous exposure command is issued each time the timer counts out. For example, in practical applications, when the input clock of the camera sensor is 40 MHz, the clock phase will drift for one exposure period (1 ms) in about 30 seconds, so it is necessary to perform a simultaneous exposure within 30 s, and then every 20 s can be set. An instruction to issue a simultaneous exposure. If the synchronous exposure command is issued by the control device itself, the control device also has a timer inside, which functions the same as the timer described above. As an embodiment thereof, it is also possible to directly set an instruction that the control device itself issues a synchronized exposure every time a predetermined time elapses.

In the embodiment of the present invention, in the multi-camera system, if the initial settings of each camera are the same and the resolutions of the images are equal, the exposure time of each camera in the multi-camera system is theoretically the same. According to the foregoing description, in practice, due to some factors such as temperature and humidity, the oscillation period of the actual crystal oscillator is also changing, and is not completely constant, so that the problem of unsynchronized exposure occurs. In order to solve the problem of unsynchronized exposure, in this step, the hardware time code of each camera in the multi-camera system needs to be acquired, so that the exposure time of each camera of the multi-camera system can be adjusted according to the acquired hardware time code, so that The exposure time of all cameras is synchronized.

Among them, each camera has a time code register inside, which is used to read and write the hardware time code of the current camera. After the camera sensor starts working, the hardware timer module starts timing. The exposure start time and exposure duration of each frame of the camera are timed by the hardware time code recorded by the hardware timer. Suppose there are N cameras in a multi-camera system. Then, the process of specifically obtaining the initial hardware time code may be: respectively sending a hardware time code acquisition request to each camera in the multi-camera system, and the camera in the multi-camera system reads its own time code register when receiving the request. The hardware time code returns the hardware time code, and receives the hardware time code sent by each camera in the multi-camera system and counts as the initial hardware time code T ₁ , T ₂ , T ₃ ... T _{N , respectively} . At this time, initial hardware time codes T ₁ , T ₂ , T ₃ ... T _N corresponding to each camera in the multi-camera system are obtained.

Step S402, determining a synchronization reference value according to the plurality of initial hardware time codes, and determining a frame compensation value corresponding to each camera in the multi-camera system according to the synchronization reference value and an initial hardware time code of each camera.

After acquiring the initial hardware time code corresponding to the plurality of cameras, the synchronization reference value may be determined according to the plurality of initial hardware time codes. When determining the synchronization reference value, any one of the plurality of initial hardware time codes may be selected as the synchronization reference value, and the maximum value or the minimum value of the plurality of initial hardware time codes may be selected as the synchronization reference value, of course, An average of the plurality of initial hardware time codes is calculated and used as a synchronization reference value. A frame compensation value for each camera is then determined based on the synchronization reference value and the plurality of initial hardware time codes obtained. After determining the synchronization reference value, it is also necessary to calculate the frame compensation value of each camera based on the acquired initial hardware time code of each camera and the synchronization reference value. Specifically, the corresponding frame compensation value of each camera is calculated based on the deviation of the synchronization reference value from the initial hardware time code of the camera.

Step S403, sending the frame compensation value corresponding to each camera to each camera corresponding to the multi-camera system, so that each camera adjusts the length of the image according to the corresponding frame compensation value so that all the multi-camera systems The camera's exposure time is synchronized.

After calculating the frame compensation value corresponding to each camera, it is sent to all the cameras in the multi-camera system. After receiving the frame compensation value, the camera in the multi-camera system updates the camera's internal frame extension register so as to be in the multi-camera system. Each camera is able to align the exposure time when capturing images.

It should be noted that if the determined synchronization reference value and the initial hardware time code of the camera do not deviate, it means that the camera does not need to perform frame compensation during the current synchronous exposure.

Another point to be explained is that when the frame length of the image is adjusted according to the frame compensation value, the frame length of the current image frame can be adjusted, so that the camera in the multi-camera system can achieve synchronous exposure when acquiring the next frame image, that is to say, The next frame image is the image to be synchronized. Of course, the camera can also adjust the frame length of the next frame image according to the frame compensation value, so that the camera in the multi-camera system can achieve synchronous exposure when acquiring the next frame image, that is, the next frame image is the image to be synchronized. And so on.

After receiving the instruction of the synchronous exposure, the embodiment of the present invention obtains the initial hardware time code of each camera, and determines the synchronization reference value according to the plurality of initial hardware time codes, and according to the initial hardware time code and synchronization of each camera. Deviation between the reference values, determining a frame compensation value corresponding to each camera and transmitting the frame compensation value to the corresponding camera, so that the camera in the multi-camera system can adjust the frame length of the image according to the determined frame compensation value, thereby Each camera in a multi-camera system synchronizes exposure time when acquiring images.

It can be understood that the reason for causing the multiple camera exposure times in the multi-camera system to be out of sync is that there are other factors besides the crystal oscillation period is not equal. For example, the network delay when acquiring the initial time code of each camera in the multi-camera system, the operation delay when acquiring the initial time code of each camera, and the hardware cumulative delay value of the camera itself. Since the obtained initial hardware time code includes the above delay values, in order to further improve the synchronization accuracy of the multi-camera system, after the initial hardware time code is acquired, before the frame compensation value is determined, the acquired initial hardware time code may also be acquired. Perform delay correction processing. It can be understood that the delay correction processing may include at least one of a network delay correction processing, an operation delay correction processing, and a hardware cumulative correction processing. Correspondingly, after the initial hardware time code is corrected, the corrected hardware time code is obtained when the synchronization reference value is obtained, and the corrected hardware time code is also used when determining the frame compensation value of each camera. Hereinafter, the delay correction processing including the network delay correction processing, the operation delay correction processing, and the hardware cumulative correction processing will be described in detail as an example.

FIG. 5 is a schematic flowchart of still another embodiment of step S101 in the first embodiment of the present invention. As shown in FIG. 5, the synchronous exposure method may include the following steps:

Step S501, after receiving the instruction of the synchronous exposure, acquiring an initial hardware time code of each camera in the multi-camera system, to obtain a plurality of initial hardware time codes.

Step S502, performing hardware accumulation correction processing, network delay processing, and operation delay processing on the obtained plurality of initial hardware time codes in sequence.

In the following, specific operational procedures of hardware cumulative correction processing, network delay processing, and operation delay processing will be separately described.

First, hardware cumulative correction processing is sequentially performed on a plurality of initial hardware time codes.

When the hardware cumulative correction processing is performed, the hardware timer starts to count after the camera sensor starts to work. After a certain period of operation, the crystal oscillator generates a certain cumulative error. To eliminate this error, it can be used in each frame of the image. The preset position (such as the position of the 100th pixel) is set to trigger the CPU hardware interrupt. When the interrupt is triggered, the hardware timer will automatically latch the time code of the current time. Each time an interrupt is triggered, a time code is latched.

In step 502, when hardware initial correction processing is performed on a plurality of initial hardware time codes, the operation flow may be performed according to the flow shown in FIG. 6.

As shown in FIG. 6 , when the flowchart of the hardware cumulative correction processing in step 502 is performed, the following steps may be included:

Step 601: Corresponding to acquiring an interrupt time code of the last interrupt trigger time of each camera.

Step 602: Perform a difference operation between the plurality of initial hardware time codes and the acquired interrupt time code, and obtain a corrected hardware time code of each camera.

According to the foregoing description, the hardware timer can automatically latch a time code when an interrupt is generated. Therefore, after reading each of its own initial hardware time code, each camera also reads the hardware time code of the most recent interrupt trigger time, which is recorded as the interrupt time code. Then, the control device compares the initial hardware time code with the interrupt time code to eliminate the error generated by the crystal oscillator and obtain the corrected hardware time code after the hardware cumulative delay processing.

For example, when the initial hardware time code of the camera is corrected, if the initial hardware time code of the camera is T _i , and the acquired interrupt time code of the last interrupt of the camera is T _i0 , the hardware cumulative correction processing operation is performed. The corrected hardware time code K _i = T _i - T _i0 of the following camera, where T _i is the initial hardware time code of camera i, and T _i0 is the interrupt time code of the most recent interruption of camera i, i ranges from 1 to N.

Second, network delay correction processing is performed on the initial hardware time code.

As can be seen from the foregoing, when acquiring the initial hardware time code of each camera, it is necessary to send a hardware time code acquisition request to each camera, and the camera in the multi-camera system passes the acquisition request of the hardware time code. Its own time code register reads its own hardware time code and returns the hardware time code. The time elapsed from receiving a request to each camera in the multi-camera system to receive the request is the network delay in the embodiment of the present invention.

Specifically, when the network delay correction processing is performed on the initial hardware time code, the operation may be specifically performed according to the flow shown in FIG. 7.

As shown in FIG. 7 , it is a schematic flowchart of an embodiment of performing network delay correction processing on an initial hardware time code, and the specific method may include:

Step 701: Acquire a network delay value between each camera in the local and multi-camera system.

Step 702: Calculate a corrected hardware time code of each camera according to the plurality of initial hardware time codes and the obtained network delay value between the local and each camera in the multi-camera system.

When the specific operation of step 701, the specific operation method may be, for example:

After the synchronous exposure task is started, the network delay between the local (ie, control device) and each camera in the multi-camera system is measured by the IEEE 1588 Precision Clock Synchronization Protocol and converted in units of the sensor clock crystal period. The network delay between the control device and each camera in the multi-camera system is obtained.

It should be noted that, in step 702, the control device corrects the hardware time of the camera after performing a difference operation on the network delay value between the obtained initial hardware time code and the acquired self and each camera. The code M _i = T _i - Y _i , where T _i is the initial hardware time code of camera i, the network delay value of Y _i camera i, and the value of i ranges from 1 to N.

At the same time, since the hardware cumulative correction processing has been performed on the initial hardware delay code in step 502, the hardware time code after the hardware cumulative correction processing, that is, T _i - T _i0 , should be used in the difference calculation in this step. Where i ranges from 1 to N. If the hardware cumulative correction processing is not performed in the foregoing, when the difference calculation is performed in this step, the initial hardware time code T _i should be used, where i ranges from 1 to N.

Hereinafter, a detailed description will be given by way of specific examples.

Assume that the network delay values between each of the acquired local and multi-camera systems are Y ₁ , Y ₂ , Y ₃ ... Y _{N , respectively} .

Then, after the hardware cumulative correction processing and the network delay correction processing, the corrected hardware time code M _i =K _i - Y _i = T _i - T _i0 - Y _{i of the} obtained camera, wherein i has a value range of 1 To N.

Third, the operation delay correction processing is performed on the initial hardware time code.

In particular, when acquiring the initial hardware time code of each camera in the multi-camera system, if it is necessary to separately obtain the initial hardware time code of each camera, after acquiring the initial hardware time code of a certain camera, There are multiple cameras in the camera system, and the instructions to read the initial hardware timecode of the first camera and the instructions to read the initial hardware timecode of the second camera are not exactly the same. Therefore, when correcting the initial hardware time code, you also need to consider the operation delay. If the time code of each camera in the multi-camera system is read by broadcast, the operation delay can be ignored. Specific can be selected according to the actual situation.

As shown in FIG. 8 , it is a schematic flowchart of an embodiment of performing an operation delay correction process on an initial hardware time code, including the following steps:

Step S801, when acquiring the initial hardware time code of each camera, reading the local instantaneous hardware time code.

Step S802, performing a difference operation between the local instantaneous hardware time code read each time and the local instantaneous hardware time code read when the initial hardware time code of the first camera is acquired, to obtain a local (external control device) and The operational delay value between each camera.

Step S803, calculating a corrected hardware time code of each camera according to the plurality of initial hardware time codes and the obtained operation delay value.

In step S801, before the initial hardware time code acquisition request is sent to each camera, the external control device local device, that is, the local hardware time code, is recorded as the instantaneous hardware time code. Then, an initial hardware time code acquisition request is sent to each camera in the multi-camera system, and the camera in the multi-camera system reads the hardware time code of the camera and returns to the camera's local hardware time after receiving the request. Code to control device. At this time, the local instantaneous hardware time code read when reading the initial hardware time code of the first camera needs to be used as a reference; the instantaneous hardware of the control device is read each time the initial hardware time code of other cameras is read. The difference between the time code and its own instantaneous hardware time code read when reading the initial hardware time code of the first camera is the operation delay value because the control device reads its own instantaneous hardware time code. The initial hardware time code of the first camera will be obtained immediately, so it can be considered that there is no operation delay between the control device and the first camera, and the control device is reading the time at the time of acquiring the initial hardware time code of the other camera. After the initial hardware time code of a camera, there is an operational delay between the instantaneous hardware time code of the control device itself read by the control device when reading the initial hardware time code of the first camera, so calculation is required. The operation delay during this time.

That is, the operation delay value C _i = T _1i - T ₁₁ . Wherein, T _1i is a local instantaneous hardware time code read before acquiring the initial hardware time code of the i-th camera, and T ₁₁ is a local instantaneous hardware time code read when the hardware time code of the first camera is read. Where i has a value ranging from 1 to N. When i is equal to 1, it indicates the operation delay value between the control device and the first camera. Wherein, the operation delay value of the control device and the first camera is 0, and may also be recorded as C ₁ =T ₁₁ - T ₁₁ .

Then, after the operation delay correction processing, the corrected hardware time code of the camera is N _i = T _i - C _i , where T _i is the initial hardware time code of camera i, the operation delay value of C _i camera i, and the taking of i Values range from 1 to N. The corrected hardware time code N _i = T _i - C _i of the camera after the operation delay correction processing, wherein i ranges from 1 to N.

It should be noted that since the hardware cumulative correction processing and the network delay correction processing have been performed on the initial hardware delay code in step 502, the hardware cumulative correction processing and network extension should be used in the difference calculation in this step. The hardware time code after processing is corrected, that is, M _i , where i ranges from 1 to N. If the hardware cumulative correction processing and the network delay correction processing are not performed in the foregoing, when the difference calculation is performed in this step, the initial hardware time code T _i should be used, where i ranges from 1 to N.

Hereinafter, a detailed description will be given by way of specific examples.

It is assumed that the operational delay values obtained between each of the cameras in the multi-camera system are C ₁ , C ₂ , C ₃ ... C _{N , respectively} .

Then, after the hardware cumulative correction processing, the network delay correction processing, and the operation delay processing, the obtained corrected hardware time code of the camera is N _i =K _i - Y _i -C _i = T _i - T _i0 - Y _i -( T _1i - T ₁₁ ), where i has a value ranging from 1 to N.

It should be noted that although the above embodiment adopts three delay correction processings of network delay correction processing, operation delay correction processing, and hardware cumulative correction processing, in practical applications, only one of them may be selected or Two delay correction processing. Which delay correction processing is selected in the process of correcting the hardware time code by performing the delay correction processing on the initial hardware time code, and correspondingly, which delay correction result obtained by the delay correction processing is calculated together with the initial hardware time code Obtaining the modified hardware time code, the embodiment of selecting only one of the delay correction processing in the above three delay correction processing and the embodiment for selecting any two of the delay correction processing are not illustrated herein, and can be referred to The calculation process of the above embodiment is obtained.

Step 503: Determine the synchronization reference value according to the plurality of modified hardware time codes, and determine frame compensation corresponding to each camera in the multi-camera system according to the synchronization reference value and the corrected hardware time code of each camera. value.

Since the initial hardware time code is subjected to the delay correction processing in step 502, in this step, when the synchronization reference value is determined, it is necessary to determine the synchronization reference value based on the plurality of corrected time codes after the correction processing. Specifically, when determining the synchronization reference value, any one of the plurality of modified hardware time codes may be selected as the synchronization reference value, and the maximum value or the minimum value of the plurality of modified hardware time codes may be selected as the synchronization reference value. It is of course also possible to calculate an average of the plurality of modified hardware time codes and use the average as a synchronization reference value.

If only the hardware cumulative correction processing is performed on the initial hardware time code, then the synchronization reference value needs to be determined according to the hardware time code K _i after the hardware cumulative correction processing, and so on. In the embodiment of the present invention, the hardware cumulative correction processing, the network delay correction processing, and the operation delay correction processing are performed on the initial hardware time code, then the hardware cumulative correction processing, the network delay correction processing, and the operation delay should be performed according to the hardware. The corrected hardware time code N _i of each camera obtained after the process determines the synchronization reference value. After selecting the sync reference value, all cameras are aligned with the camera corresponding to the selected sync reference value.

In the embodiment of the present invention, since the exposure is determined according to the time code, if the corrected hardware time code of the camera is greater than the synchronization reference value, the hardware time code of the camera is faster than the synchronous reference value, and the current camera needs to be The frame image or the next frame image is extended for a certain period of time, so that the time code of the camera corresponding to the synchronization reference value can be caught up, so that the exposure time is synchronized when the lower frame or the lower frame image is acquired; if the corrected hardware time code of the camera is smaller than the synchronization The reference value indicates that the time code of the camera is slow, and it is necessary to catch up with the time code of the camera corresponding to the synchronization reference value. Therefore, it is necessary to shorten the current frame image or the next frame image of the camera for a certain time so as to synchronize the reference value. The camera's time code can be caught up to synchronize exposure when capturing the next frame or the next frame of image.

The method for synchronously exposing a multi-camera system according to an embodiment of the present invention acquires an initial hardware time code of each camera after receiving an instruction of synchronous exposure, and performs delay correction processing on the plurality of initial hardware time codes to obtain a plurality of Correcting a hardware time code, and determining a synchronization reference value according to the plurality of modified hardware time codes, and determining a frame compensation corresponding to each camera in the multi-camera system according to the synchronization reference value and an initial hardware time code of each camera The value is such that each camera can adjust the frame length of the image based on the determined frame compensation value such that each camera in the multi-camera system synchronizes the exposure time when acquiring the image.

When synchronizing exposure of each camera in the multi-camera system, as still another embodiment, the function of the control device external to the multi-camera system can be implemented by one camera in the multi-camera system. At this time, one camera of the multi-camera system can be selected as the main camera, and the other cameras are used as the slave camera. The above method can be adopted by the external camera in the multi-camera system when implementing the simultaneous exposure of each camera in the multi-camera system. achieve. That is to say, at this time, the main camera as a camera device in the multi-camera system can realize all the functions of the slave camera in the multi-camera system, in addition to all the functions of the previously connected control device. Of course, when the main camera realizes the function of the external control device, the local data information of the external device obtained by the external control device will be replaced by the data acquisition of the main camera to obtain the local camera, and the same, before the external device and the multi-camera The difference in data between each camera in the system will be replaced by the difference in data between the main camera and the slave camera.

9 is a schematic flowchart of still another embodiment of a multi-camera system synchronous exposure method provided by the present invention. As shown in FIG. 9, the synchronous exposure method may include the following steps:

Step S901, after receiving the instruction of synchronous exposure, acquiring an initial hardware time code of each camera in the multi-camera system, to obtain a plurality of initial hardware time codes.

Step S902, performing hardware accumulation correction processing, network delay processing, and operation delay processing on the obtained plurality of initial hardware time codes in sequence to obtain a plurality of modified hardware time codes.

Step S903, determining a synchronization reference value according to the plurality of modified hardware time codes.

In step S904, the frame compensation value of the camera is calculated according to the formula: B _i = (N _{i -} S) % FrameLength.

The difference between this embodiment and the embodiment shown in FIG. 5 is as follows:

When determining the frame compensation value, the formula in step S904 is specifically employed. In step S904, B _i represents the frame compensation value of the camera i, N _i represents the corrected hardware time code of the camera i after the delay correction processing, S represents the synchronization reference value, and FrameLength represents one of each camera in the multi-camera system. The size of the frame image in units of oscillation periods, and % indicates the modulo operation. The specific frame compensation value is the size of the camera one frame image in units of the oscillation period of the crystal oscillator, that is, the size converted into the time code. The modulo operation is performed so that the frame compensation value of the camera does not exceed the frame length of one frame of image (the length of time of one frame of image converted into time code), as long as the phase of the clock is aligned.

Second, in the specific processing, the determined synchronization reference value may be a minimum value among the plurality of modified hardware time codes, that is, a minimum value is selected from the plurality of modified hardware time codes as the synchronization reference value. The purpose of selecting the minimum value in the hardware timecode is to simplify the calculations and to get better results. At this time, all cameras only need to lengthen the length of the current frame or the next frame image.

After calculating the frame compensation value of the camera, the camera in the multi-camera system can adjust the length of the current frame or the next frame image according to the frame compensation value, so that the camera can realize when acquiring the lower frame or the lower frame image. Synchronous exposure.

It should be understood that, in the above embodiments, the size of the serial number of each step does not mean the order of execution sequence, and the order of execution of each step should be determined by its function and internal logic, and should not constitute any implementation process of the embodiment of the present invention. limited.

1 to 9 above are described in detail corresponding to the synchronous exposure method for a multi-camera system, and the apparatus, the terminal device, and the computer-readable storage medium to which the above-described synchronous exposure method is applied will be described in detail below with reference to the accompanying drawings. To avoid redundancy, the terms already described above may not be repeatedly described below.

Referring to FIG. 10, FIG. 10 is a structural block diagram of a synchronous exposure apparatus 1000 according to the present invention. For the convenience of description, only parts related to the embodiment of the present invention are shown. The synchronous exposure device 1000 as a control device external to the multi-camera system may be a software unit, a hardware unit or a combination of soft and hard units built in the terminal device, or may be integrated into the terminal device as a separate pendant. The synchronous exposure apparatus 1000 may also be a software unit, a hardware unit, or a combination of soft and hard units built in the main camera, or may be integrated into the main camera as a separate pendant. The synchronous exposure apparatus 1000 includes:

a synchronization module 1001, configured to adjust a camera in the multi-camera system to cause simultaneous exposure when all cameras in the multi-camera system acquire images;

The association module 1002 is configured to acquire synchronization identification information, so that the synchronization identification information is associated with the image to be synchronized of each camera in the multi-camera system, so that the images to be synchronized of each camera have the same synchronization identification information. The image to be synchronized of each camera is an image respectively acquired by each camera when all the cameras in the multi-camera system are simultaneously exposed.

Optionally, the synchronization identifier information includes an image frame number.

The association module 1002 includes:

a frame number obtaining unit, configured to acquire an image frame number of an image of any one of the cameras to be synchronized in the multi-camera system, and use the image frame number as the synchronization identification information;

a sending unit, configured to send an image frame number of the image to be synchronized to a corresponding camera in the multi-camera system, so that a camera in the multi-camera system adjusts an image to be synchronized according to the received image frame number Image frame number.

Optionally, the device further includes:

a synchronization subsequence generation module, configured to generate synchronization identifier subsequence information according to the synchronization identification information, so that each camera in the multi camera system sequentially sequentially synchronizes the synchronization identifier subsequence information with an image sequence after the image to be synchronized The association causes the sequence of images following the image to be synchronized to have the same synchronization identification subsequence information in sequence.

Optionally, the synchronization module includes:

a selecting unit, configured to select one of the cameras in the multi-camera system as a main camera, and the camera other than the main camera as a slave camera;

An acquiring unit, configured to acquire a difference between an exposure time of the main camera and the slave camera;

And an adjusting unit, configured to adjust a camera in the multi-camera system according to a difference between the main camera and the slave camera exposure time such that all cameras in the multi-camera system acquire images synchronously.

It will be clearly understood by those skilled in the art that for the convenience and brevity of the description, only the division of each functional module described above is exemplified. In practical applications, the above function assignment can be completed by different functional units and modules as needed. That is, the internal structure of the device is divided into different functional units or modules to perform all or part of the functions described above. Each functional module in the embodiment may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit or module, and the integrated unit or module may adopt hardware. The form is implemented in the form of a software functional unit. In addition, the specific names of the respective functional modules are only for the purpose of distinguishing from each other, and are not intended to limit the scope of protection of the present application. For the specific working process of the module in the foregoing device, refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

FIG. 11 is a schematic block diagram of a terminal device according to an embodiment of the present invention. The terminal device can also be a camera in a multi-camera system. As shown in FIG. 11, the terminal device 11 of this embodiment includes: one or more processors 110, a memory 111, and a computer program 112 stored in the memory 111 and operable on the processor 110. When the processor 110 executes the computer program 112, the steps in the above embodiments of the respective synchronous exposure methods are implemented, such as steps S101 to S102 shown in FIG. Alternatively, the processor 110 implements the functions of the modules/units in the embodiment of the synchronous exposure apparatus when the computer program 112 is executed, such as the functions of the modules 1001 to 1002 shown in FIG.

Illustratively, the computer program 112 can be partitioned into one or more modules/units that are stored in the memory 111 and executed by the processor 110 to complete this invention. The one or more modules/units may be a series of computer program instruction segments capable of performing a particular function, the instruction segments being used to describe the execution of the computer program 112 in the terminal device 11. For example, the computer program 112 can be partitioned into a synchronization module, an association module.

a synchronization module for adjusting a camera in the multi-camera system to cause simultaneous exposure of all cameras in the multi-camera system when acquiring images;

The association module includes:

a sending unit, sending an image frame number of the image to be synchronized to a corresponding camera in the multi-camera system, so that the camera in the multi-camera system adjusts an image of the image to be synchronized according to the received image frame number Frame number.

Optionally, it also includes:

Optionally, the synchronization module specifically includes:

The terminal device includes but is not limited to the processor 110 and the memory 111. It will be understood by those skilled in the art that FIG. 11 is only an example of the terminal device 11, and does not constitute a limitation of the terminal device 11, and may include more or less components than those illustrated, or combine some components or different components. For example, the terminal device may further include an input device, an output device, a network access device, a bus, and the like.

The memory 111 is configured to store software programs, modules, units, and data information required in the terminal device, and the processor 110 executes various functional applications by running software programs, modules, and units stored in the memory 111. And data processing. The memory 111 can include read only memory and random access memory and provides instructions and data to the processor 110. A portion of the memory 111 may also include a non-volatile random access memory. For example, the memory 111 can also store information of a device type.

The processor 110 can be a central processing unit (Central Processing Unit (CPU), which can also be other general-purpose processors, digital signal processors (DSPs), and application specific integrated circuits (Application). Specific Integrated Circuit (ASIC), Field-Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic device, discrete hardware components, etc. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The processor is a control center of the terminal device, and connects various parts of the entire terminal device by using various interfaces and lines.

In a specific implementation, the processor 110 and the memory 111 described in the embodiments of the present invention may implement the implementation manner described in the embodiment of the synchronous exposure method provided by the embodiment of the present invention, and may also be implemented in the embodiment of the synchronous exposure apparatus. The implementation of the description will not be described here.

In addition, an embodiment of the present invention further provides a computer readable storage medium, where the computer readable storage medium stores a computer program, and when the computer program is executed by one or more processors, the synchronization provided by the embodiment of the present invention is implemented. The steps of the exposure method.

In the above embodiments, the descriptions of the various embodiments are different, and the parts that are not detailed or described in a certain embodiment can be referred to the related descriptions of other embodiments.

Those of ordinary skill in the art will appreciate that the modules and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both, for clarity of hardware and software. Interchangeability, the composition and steps of the various examples have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

In the embodiments provided by the present invention, it should be understood that the disclosed method, apparatus, and terminal device may be implemented in other manners. For example, the embodiments described above are merely illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined. Or it can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional module in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the embodiments of the present invention may contribute to the prior art or all or part of the technical solution may be embodied in the form of a software product stored in a storage. The medium includes a plurality of instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) or a processor to perform all or part of the steps of the methods described in various embodiments of the embodiments of the present invention. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), and a random access memory (RAM, Random Access). A variety of media that can store program code, such as a memory, a disk, or an optical disk.

The embodiments described above are only for explaining the technical solutions of the present invention, and are not intended to be limiting; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art will understand that The technical solutions described in the examples are modified, or the equivalents of the technical features are replaced by the equivalents of the technical solutions of the embodiments of the present invention.

Claims

A synchronous exposure method for a multi-camera system, comprising:

Adjusting an exposure time of a camera in the multi-camera system such that all cameras in the multi-camera system acquire images synchronously;

Acquiring synchronization identification information, so that the synchronization identification information is associated with the image to be synchronized of each camera in the multi-camera system, such that the images to be synchronized of each camera have the same synchronization identification information, and each camera is to be The synchronized image is an image acquired by each camera separately when all cameras in the multi-camera system are simultaneously exposed.
The method of claim 1 wherein said synchronization identification information comprises an image frame number.
The method according to claim 2, wherein the acquiring the synchronization identification information to facilitate the association of the synchronization identification information with the image to be synchronized of each camera in the multi-camera system comprises:

Obtaining an image frame number of an image of any one of the plurality of camera systems to be synchronized, and using the image frame number as the synchronization identification information;

And transmitting an image frame number of the image to be synchronized to a corresponding camera in the multi-camera system, so that the camera in the multi-camera system adjusts an image frame number of the image to be synchronized according to the received image frame number.
The method of claim 1 wherein said adjusting said camera in said multi-camera system causes simultaneous synchronization of all cameras in said multi-camera system when acquiring images comprises:

Selecting one of the multi-camera systems as a main camera, the camera other than the main camera as a slave camera;

Obtaining a difference between an exposure time of the main camera and the slave camera;

Adjusting the camera in the multi-camera system according to a difference between the primary camera and the slave camera exposure time causes simultaneous synchronization of all cameras in the multi-camera system when acquiring images.
The method according to claim 1, wherein after the obtaining the synchronization identification information, the method further comprises:

Generating synchronization identification subsequence information according to the synchronization identification information, so that each camera in the multi-camera system sequentially associates the synchronization identification sub-sequence information with an image sequence after the image to be synchronized such that the image after the image to be synchronized The sequences in turn have the same synchronization identification subsequence information.
A synchronous exposure device for use in a multi-camera system, comprising:

a synchronization module, configured to adjust an exposure time of the camera in the multi-camera system, such that all cameras in the multi-camera system simultaneously perform exposure when acquiring images;

An association module, configured to acquire synchronization identification information, so that the synchronization identification information is associated with an image to be synchronized of each camera in the multi-camera system, such that images to be synchronized of each camera have the same synchronization identification information, The image to be synchronized of each camera is an image separately acquired by each camera when all the cameras in the multi-camera system are simultaneously exposed.
The apparatus according to claim 6, wherein said synchronization identification information comprises an image frame number;

The association module includes:

a frame number obtaining unit, configured to acquire an image frame number of an image of any one of the cameras to be synchronized in the multi-camera system, and use the image frame number as the synchronization identification information;

a sending unit, configured to send an image frame number of the image to be synchronized to a corresponding camera in the multi-camera system, so that a camera in the multi-camera system adjusts an image to be synchronized according to the received image frame number Image frame number.
The device according to claim 6, wherein the synchronization module specifically includes:

a selecting unit, configured to select one of the cameras in the multi-camera system as a main camera, and the camera other than the main camera as a slave camera;

An acquiring unit, configured to acquire a difference between an exposure time of the main camera and the slave camera;

And an adjusting unit, configured to adjust a camera in the multi-camera system according to a difference between the main camera and the slave camera exposure time such that all cameras in the multi-camera system acquire images synchronously.
A terminal device for use in a multi-camera system, characterized in that the terminal device comprises a memory, a processor, and a computer program stored in the memory and operable on the processor, the processor executing the The steps of the method of any one of claims 1 to 5 are carried out when the computer program is described.
A computer readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the steps of the method of any one of claims 1 to 5.