WO2021102959A1

WO2021102959A1 - Focus adjustment method, camera module, and computer readable storage medium

Info

Publication number: WO2021102959A1
Application number: PCT/CN2019/122104
Authority: WO
Inventors: 韩守谦
Original assignee: 深圳市大疆创新科技有限公司
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2021-06-03

Abstract

A focus adjustment method, a camera module, and a computer readable storage medium. The focus adjustment method comprises: acquiring a first image frame, a second image frame, and a third image frame that are correspondingly photographed by a camera module at a current focal point, a front focal point, and a rear focal point (S201), the current focal point being between the front focal point and the rear focal point; identifying the first image frame, the second image frame, and the third image frame, and determining the focal point adjustment direction and the focal point adjustment distance of the camera module (S202); and adjusting the current focal point of the camera module according to the focal point adjustment direction and the focal point adjustment distance of the camera module (S203). Therefore, the focal point of the camera module can be automatically adjusted when the object distance changes, and user experience is not affected.

Description

Focus adjustment method, camera module and computer readable storage medium

Technical field

This application relates to the field of photography technology, and in particular to a focus adjustment method, camera module, and computer-readable storage medium.

Background technique

At present, when taking pictures, for example, when a digital camera takes a picture, an auto focus (AF) mode is usually used to realize the camera focusing. There is no need for the user to frequently tap an object on the camera's touch screen to focus, and the camera itself triggers and completes the auto focusing.

However, it has been found in practice that the camera focusing speed is slower and the focusing time is longer in the existing auto-focusing scheme. Especially when there is a change in the object distance of the shooting object, the focus quality of the camera is not high, resulting in low definition of the shooting picture, which affects the user experience.

Summary of the invention

The embodiments of the present application provide a focus adjustment method, a camera module, and a computer-readable storage medium, which can automatically adjust the focus of the camera module when the object distance changes without affecting the user experience.

In a first aspect, an embodiment of the present application provides a focus adjustment method, and the method includes:

Acquire the first frame image, the second frame image, and the third frame image corresponding to the camera module at the current focus, the front focus, and the back focus, and the current focus is between the front focus and the back focus; The first frame image, the second frame image, and the third frame image determine the focus adjustment direction and focus adjustment distance of the camera module; adjust the current focus of the camera module according to the focus adjustment direction and focus adjustment distance of the camera module.

In an implementation manner, before acquiring the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module at the current focus, the front focus, and the back focus, the method further includes: determining the camera The front focus and back focus of the module shooting.

In one implementation, the specific implementation for determining the front focus and the rear focus of the camera module is to obtain the shooting parameters of the camera module when shooting at the current focus. The shooting parameters include the aperture value and the lens aperture. Diameter and step length factor. The step length factor is used to indicate the movement step length of the camera module lens within a unit distance; distance conversion is performed on the shooting parameters to obtain the distance threshold for the current focus to support movement; the current focus is moved to the first direction The front focus is obtained by one distance, and the rear focus is obtained by moving the current focus in the second direction by a second distance. The first direction is opposite to the second direction, and both the first distance and the second distance are less than or equal to the distance threshold.

In one implementation, both the first distance and the second distance are equal to the distance threshold.

In one implementation, the distance conversion is performed on the shooting parameters to obtain the distance threshold value of the current focus support movement: according to the aperture value and the diameter of the lens aperture, the out-of-focus distance of the camera module is calculated; according to the out-of-focus The distance and step factor are calculated to obtain the distance threshold for the current focus to support movement.

In an implementation manner, the specific implementation manner of identifying the first frame image, the second frame image, and the third frame image, and determining the focus adjustment direction and focus adjustment distance of the camera module is: Perform image recognition on the second frame of image and the third frame of image, and calculate the corresponding current focus value, front focus value and back focus value. The focus value is used to reflect the definition of the frame image corresponding to the focus value; if the current focus value is defined Between the front focus value and the rear focus value, and the front focus value is greater than the rear focus value, it is determined that the focus adjustment direction of the camera module is the first direction from the current focus to the front focus adjustment, and the focus adjustment distance is The distance between the current focus and the front focus; the current focus of the camera module is adjusted to the front focus along the first direction.

In one implementation, the specific implementation of identifying the first frame image, the second frame image, and the third frame image, and determining the focus adjustment direction and focus adjustment distance of the camera module is as follows: The image and the third frame of image are recognized, and the current focus value, front focus value and back focus value are calculated correspondingly. The focus value is used to reflect the sharpness of the frame image corresponding to the focus value; if the current focus value is between the front focus value Between the focus value and the rear focus value, and the front focus value is less than the rear focus value, the focus adjustment direction of the camera module is determined to be the second direction of the current focus to the rear focus adjustment, and the focus adjustment distance of the camera module Is the distance between the current focus and the rear focus; the current focus of the camera module is adjusted to the rear focus along the second direction.

In one implementation, the first frame of image, the second frame of image, and the third frame of image are identified, and the focus adjustment direction and focus adjustment distance of the camera module are determined. The specific implementation is as follows: And the third frame of image for image recognition, correspondingly calculate the current focus value, front focus value and back focus value, the focus value is used to reflect the definition of the frame image corresponding to the focus value; if the current focus value is greater than the front focus Value and the rear focus value, it is determined that there is no need to adjust the current focus of the camera module, and the focus adjustment direction and focus adjustment distance of the camera module are both empty.

In a second aspect, an embodiment of the present application provides a camera system, the camera system includes a memory and a processor, wherein:

The memory is used to store a computer program;

The processor calls a computer program for:

In a third aspect, an embodiment of the present application provides a camera module that is deployed in the camera system described in the embodiment of the present application in the second aspect, and the camera system is used for:

In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program stored on the computer-readable storage medium, and when the computer program is executed, it implements the same as described in the embodiment of the present application in the first aspect. The focus adjustment method.

In the embodiment of the present application, the camera system obtains the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module at the current focus, the front focus, and the back focus. The current focus is between the front focus and the back focus. Between the focus and the rear focus; identify the first frame image, the second frame image and the third frame image, determine the focus adjustment direction and focus adjustment distance of the camera module; according to the focus adjustment direction and focus adjustment distance of the camera module, Adjust the current focus of the camera module. Through the embodiments of the present application, when the object distance changes, the focus adjustment direction and focus adjustment distance of the camera module are determined by the current focus, front focus, and rear focus of the camera module, so that the focus of the camera module can be adjusted. auto-adjust. The current focus is between the front focus and the rear focus, so the impact on the clarity of the image is small, and the user experience may not be affected.

Description of the drawings

In order to explain the embodiments of the present application or the technical solutions in the prior art more clearly, the following will briefly introduce the drawings that need to be used in the embodiments. Obviously, the drawings in the following description are only some of the present application. Embodiments, for those of ordinary skill in the art, without creative work, other drawings can be obtained based on these drawings.

FIG. 1 is a schematic diagram of a focus adjustment direction provided by an embodiment of the present application;

2 is a schematic flowchart of a focus adjustment method provided by an embodiment of the present application;

FIG. 3 is a schematic diagram of an ideal lens imaging principle provided by an embodiment of the present application;

4 is a schematic diagram of the positions of a front focus and a rear focus provided by an embodiment of the present application;

FIG. 5 is a schematic diagram of a possible motor movement provided by an embodiment of the present application;

FIG. 6(a) is a schematic diagram of a possible focus adjustment direction and focus adjustment distance provided by an embodiment of the present application;

FIG. 6(b) is a schematic diagram of a possible focus adjustment direction and focus adjustment distance provided by an embodiment of the present application;

FIG. 7 is a schematic structural diagram of a camera system provided by an embodiment of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described clearly and completely in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

In modern social life, people increasingly want to record beautiful and important moments as images. Early cameras needed to use negatives (that is, video tapes) to record. With the invention of digital cameras, images can be stored directly in flash memory. The latest cameras store the image data directly in the hard disk of the body, which can not only shoot statically, but also record dynamically. With the development of technology, people have higher and higher requirements for image clarity. If you want to get a clear image, you need the camera to focus on the target object. The process of the camera changing the position of the object distance and the image distance to make the target object clear can be called focusing. The common focus mode of the current camera is auto focus-continue (AF-c). The user does not need to tap the screen frequently to focus. Instead, the camera determines whether to trigger auto focus (AF) and automatically completes the focus. .

At present, the auto focus mode mainly judges whether to trigger continuous focus based on the change of AF statistics. When continuous focus is triggered, the camera module in the camera needs to collect images at three focal points to determine the focus direction. Please refer to FIG. 1, which is a schematic diagram of a focus adjustment direction provided by an embodiment of the present application. As shown in FIG. 1, the first focus, the second focus, and the third focus represent the three focus points that the camera module needs to collect images, and the first focus represents the focus currently used by the camera module to capture images. It can be seen that when the current scheme is collecting images, the camera system controls the motors to move in one direction when the camera module adjusts the focus. Because the change of the focus will affect the clarity of the image, and the change in one direction will cause the focus to change more, and the impact on the clarity of the image is also greater, affecting the user experience; especially during the recording process, due to the target object If there is a change, or the object distance of the target object is changed due to the shaking of the lens, the sharpness of the image will not be high during the focusing process of the camera, which will seriously affect the user experience.

In order to solve the above-mentioned problems, embodiments of the present application provide a focus adjustment method, a camera module, and a computer-readable storage medium. The focus adjustment method may include: a camera system obtains the current focus, front focus, and rear focus of the camera module. The focus point corresponds to the first frame image, the second frame image, and the third frame image taken. The current focus point is between the front focus and the back focus; and the first frame image, the second frame image, and the third frame image are identified. Frame image, determine the focus adjustment direction and focus adjustment distance of the camera module; the camera system adjusts the current focus of the camera module according to the focus adjustment direction and focus adjustment distance of the camera module, so that the camera module is combined to get a clear Take pictures. The focus adjustment method can automatically adjust the focus of the camera module when the object distance changes without affecting the user experience.

Among them, the camera system includes, but is not limited to, cameras with a function of recording images, such as digital cameras, drone cameras, and handheld pan-tilt cameras, which are not limited in the embodiments of the present application.

Please refer to FIG. 2. FIG. 2 is a schematic flowchart of a focus adjustment method provided by an embodiment of the present application. The focus adjustment method may include, but is not limited to, the following steps:

S201. The camera system acquires the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module at the current focus, the front focus, and the back focus. The current focus is between the front focus and the back focus. between.

When the camera system is triggered to perform autofocus, the camera system determines the front focus and the back focus of the camera module according to the current focus. Among them, when it is detected that the camera system is activated for shooting, or before each image is taken, the camera system will be triggered to perform autofocus. Furthermore, the camera system obtains the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module at the current focus, the front focus, and the back focus. Among them, the current focus reflects the image distance set by the current image captured by the camera module. Correspondingly, the front focus can reflect the image distance of the camera module after the focus is reduced based on the current focus; the rear focus can reflect the image distance of the camera module after the focus is increased based on the current focus. Therefore, the current focus is introduced Between the front focus and the back focus.

Specifically, in practical applications, focusing is generally achieved by controlling the movement of the lens by a motor. When the camera system is triggered to perform autofocus, the camera module takes the first frame of images at the current focus, and the camera system acquires the camera module at the current focus. The shooting parameters when shooting. In order to make the user's perception low during the focusing process, that is, to ensure that the image clarity does not change significantly, it is necessary to perform distance conversion on the shooting parameters to obtain the distance threshold of the current focus support movement, that is, calculate and debug how many steps the motor takes at a time . Therefore, the camera system moves the current focus in the first direction by a first distance to obtain the front focus, and moves the current focus in the second direction by a second distance to obtain the rear focus.

Among them, the specific implementation for determining the front focus and the back focus may include steps S11-S13.

S11. The camera system acquires shooting parameters of the camera module when shooting at the current focus.

The shooting parameters are the basic parameters of the camera module. The shooting parameters include the aperture value, the diameter of the lens aperture (Sensor Pixel), and the step length factor. The shooting parameters can be pre-stored in the memory, so the camera system can obtain them from the memory, or can be obtained by the processor of the camera system by analyzing the first frame of image. Among them, the aperture value is a relative value obtained from the focal length and the diameter of the lens aperture; the diameter of the lens aperture is determined by the lens itself; the step length factor is used to indicate the movement step length of the lens of the camera module within a unit distance. For example, the sensor end of the camera module needs to move 1mm to achieve focus. If the sensor does not move and only the lens in the camera module is moved, then the lens needs to move x mm to achieve focus, and the step length factor is k- value=x mm/1mm=x.

S12. The camera system performs distance conversion on the shooting parameters to obtain a distance threshold for the current focus to support movement.

The camera system calculates the out-of-focus distance of the camera module according to the aperture value and the diameter of the lens aperture; according to the out-of-focus distance and the step-length factor, calculates the distance threshold for the current focus to support movement. Wherein, the distance threshold is the maximum distance allowed to move the lens in the camera module when a clear image can be obtained, and a clear image cannot be obtained if the distance threshold is exceeded. In practical applications, with the human eye as the standard, the camera module can obtain a clear image within a certain distance before and after the target object. This distance range can be called the depth of field, including the foreground depth and the back depth of field. The depth of field is on the side of the object. Correspondingly, the side like this can be called the depth of focus, which corresponds to the front and back focal depths. If you want to obtain a clear image, you do not need to be absolutely in focus, but a certain amount of out of focus can be allowed. As long as the distance of out of focus does not exceed the depth of focus range, the user is difficult to perceive. Therefore, the solution distance threshold can be converted into the solution range of the out-of-focus distance. Then through the step factor, the maximum distance allowed for the lens to move can be obtained by formula (2).

S _max = Defocus/K-value formula (1)

Among them, Smax represents the distance threshold, and Defocus represents the out-of-focus distance.

The specific implementation manner for solving the out-of-focus distance is not limited, and a possible implementation manner is exemplarily given below.

Please refer to FIG. 3, which is a schematic diagram of an ideal lens imaging principle provided by an embodiment of the present application. As shown in the figure, the Gaussian imaging principle can be expressed by formula (2).

1/a+1/b=1/f formula (2)

Among them, a is the image distance, b is the object distance, and f is the focal length. When the target object is at infinity, the object distance b will be equal to f, that is, the object at infinity is absolutely in focus. A point at infinity, after imaging through the lens, is still a point when it is absolutely in focus. If the point disperses into a round spot, it is because it is out of focus. The round spot can be called a circle of confusion; the more severe the loss of focus, the larger the circle of confusion. The out-of-focus distance can be expressed by formula (3).

Defocus=b-f (3)

Since the inter-object distance b is not measurable, the out-of-focus distance is calculated according to the triangle similarity principle. It is assumed that the diameter of the circle of confusion can be expressed by formula (4).

Blur_Width=Defocus×D/f Formula (4)

Among them, Blur_Width represents the diameter of the circle of confusion, and D represents the diameter of the lens aperture. Because the aperture value is obtained by the formula F=f/D. Therefore, the diameter of the circle of confusion can be expressed by formula (5).

Blur_Width=Defocus/F Formula (5)

Among them, F represents the aperture value. Therefore, the out-of-focus distance can be expressed by formula (6).

Defocus=F×Blur_Width Formula (6)

For example, if a CMOS sensor is used for lens imaging, the diameter of the circle of confusion is generally Blur_Width=2×Pixel_size. The value of the diameter of the circle of confusion is only exemplary and does not form a limitation. The value of the diameter of the circle of confusion depends on the size of the display that displays the image and the observation distance of the user. Therefore, the size of the diameter D of the lens aperture of the CMOS sensor is obtained, and the aperture value F is obtained, and then the range of the allowable out-of-focus distance can be determined, that is, the distance threshold value of the current focus support movement is obtained.

Further, the camera system obtains the distance S _{0 the} motor takes one step, and can obtain the maximum number of steps S of the motor at a time when the human eyes cannot see the obvious image blurring. Among them, _{the value of S 0} is set by the motor. If S ₀ is 1mm and the distance threshold S _max is 5mm, the motor needs to take 5 steps.

S13. The camera system moves the current focus in the first direction by the first distance to obtain the front focus, and moves the current focus in the second direction by the second distance to obtain the rear focus. The first direction is opposite to the second direction, and the first distance is opposite to the first distance. Both distances are less than or equal to the distance threshold.

Please refer to FIG. 4, which is a schematic diagram of the positions of a front focus and a rear focus provided by an embodiment of the present application. Among them, the first direction and the second direction are self-defined settings by the system, and do not form a limitation. The direction in which the current focus moves to the front focus can also be referred to as the second direction, and the direction in which the current focus moves to the rear focus is referred to as the second direction. For the first direction. And the first direction is opposite to the second direction, so that the current focus is between the front focus and the back focus. Secondly, both the first distance and the second distance are less than or equal to the distance threshold. The machine system moves the current focus in the first direction by a first distance to obtain the front focus, and moves the current focus in the second direction by a second distance to obtain the rear focus. The specific implementation is as follows.

In an implementation manner, the first distance and the second distance are both smaller than the distance threshold, and the first distance and the second distance are equal. Therefore, the camera system can obtain the number s of steps taken by the camera through the _{distance S 0} between the first distance and the motor step. The camera system controls the motor to move in the first direction for s steps to reach the front focus, and shoot the second frame of image at the front focus. Since the first distance and the second distance are equal, the camera system controls the motor to move in the second direction for 2 seconds to reach the rear focus, and the third frame of image is captured at the rear focus.

In an implementation manner, the first distance and the second distance are both equal to the distance threshold, that is, both the first distance and the second distance are equal to S _max . Therefore, the camera system controls the motor to move in the first direction for S steps to reach the front focus, and shoot the second frame of image at the front focus. Since both the first distance and the second distance are equal to the distance threshold, the camera system controls the motor to move in the second direction for 2S steps to reach the rear focus, and the third frame of image is captured at the rear focus. Please refer to FIG. 5, which is a schematic diagram of a possible motor movement provided by an embodiment of the present application. As shown in the figure, the camera system determines a point on the left and right of the current focus, and shoots a frame of image each. It is possible to reduce the impact on the user during the focusing process.

S202: The camera system recognizes the first frame image, the second frame image, and the third frame image, and determines the focus adjustment direction and the focus adjustment distance of the camera module.

The camera system performs image recognition on the first frame image, the second frame image, and the third frame image, and calculates the corresponding current focus value, front focus value, and back focus value. The focus value is used to reflect the corresponding focus value. The sharpness of the frame image. Specifically, the camera system obtains the current focus value at the current focus by recognizing the first frame of image, which can also be referred to as the AF statistical value A; the camera system obtains the front focus value at the front focus by recognizing the second frame of image, It can also be referred to as the AF statistical value B; the camera system obtains the rear focus value at the rear focus by identifying the third frame of image, which can also be referred to as the AF statistical value C. By comparing the current focus value, the front focus value and the back focus value, the focus adjustment direction and focus adjustment distance of the camera module during auto focus are determined. The following exemplarily provides specific implementations for intensively determining the focus adjustment direction and focus adjustment distance of the camera module during autofocus.

In one implementation, if the current focus value is between the front focus value and the rear focus value, and the front focus value is greater than the rear focus value, that is, A<B, A<C, and C<B, then It is determined that the focus adjustment direction of the camera module is the first direction from the current focus to the front focus adjustment, and the focus adjustment distance is the distance between the current focus and the front focus. Please refer to FIG. 6(a). FIG. 6(a) is a schematic diagram of a possible focus adjustment direction and focus adjustment distance provided by an embodiment of the present application.

In one implementation, if the current focus value is between the front focus value and the back focus value, and the front focus value is less than the back focus value, that is, A<B, A<C, and B<C, then It is determined that the focus adjustment direction of the camera module is the second direction of the current focus to the rear focus adjustment, and the focus adjustment distance of the camera module is the distance between the current focus and the rear focus. Please refer to FIG. 6(b). FIG. 6(b) is a schematic diagram of a possible focus adjustment direction and focus adjustment distance provided by an embodiment of the present application.

In one implementation, if the current focus value is greater than the front focus value and the back focus value, that is, A>B and A>C, it is determined that the current focus of the camera module does not need to be adjusted, and the focus adjustment direction of the camera module And the focus adjustment distance is empty.

S203. The camera system adjusts the current focus of the camera module according to the focus adjustment direction and the focus adjustment distance of the camera module.

The camera system adjusts the current focus of the camera module according to the focus adjustment direction and the focus adjustment distance of the camera module to complete the focusing process. Several possible implementations are shown below.

In one implementation, the camera system adjusts the current focus of the camera module to the front focus along the first direction according to the focus adjustment direction and the focus adjustment distance of the camera module.

In one implementation, the camera system adjusts the current focus of the camera module to the rear focus along the second direction according to the focus adjustment direction and the focus adjustment distance of the camera module.

In an implementation manner, since the focus adjustment direction and the focus adjustment distance are both empty, the camera system does not adjust the current focus.

Optionally, if the image captured by the camera module at the adjusted focus is still not clear after the adjustment, the auto focus can be triggered again. Then the camera system uses the adjusted focus as the current focus, and re-executes the focus adjustment method provided in FIG. 2 in the embodiment of the present application.

Please refer to FIG. 7, which is a schematic structural diagram of another camera system provided by an embodiment of the present application. The camera system 70 described in the embodiment of the present application includes: a processor 701, a memory 702, a communication interface 703, and a camera module 704. The processor 701, the memory 702, the communication interface 703, and the camera module 704 are connected by one or more communication buses.

The aforementioned processor 701 may be a central processing unit (CPU), and the processor may also be other general-purpose processors, digital signal processors (Digital Signal Processors, DSPs), application specific integrated circuits (ASICs). ), off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. The processor 701 is configured to support the camera system to perform the corresponding functions of the camera system in the method described in FIG. 4.

The aforementioned memory 702 may include a read-only memory and a random access memory, and provides computer programs and data to the processor 701. A part of the memory 702 may also include a non-volatile random access memory. Wherein, the processor 701 calls the program instructions in the memory 702 to execute the following steps:

Acquiring the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module 704 at the current focus, the front focus, and the back focus, where the current focus is between the front focus and the back focus;

Identify the first frame image, the second frame image, and the third frame image, and determine the focus adjustment direction and focus adjustment distance of the camera module 704;

According to the focus adjustment direction and focus adjustment distance of the camera module 704, the current focus of the camera module 704 is adjusted.

In an implementation manner, the processor 701 is used to obtain the first frame image, the second frame image, and the third frame image corresponding to the camera module 704 at the current focus, the front focus, and the back focus. , Used to: determine the front focus and the back focus of the camera module 704 shooting.

In one implementation, the processor 701 is configured to: obtain the shooting parameters of the camera module 704 when shooting at the current focus, the shooting parameters include the aperture value, the diameter of the lens aperture, and the step factor, and the step factor is used to indicate The movement step length of the lens of the camera module 704 within a unit distance; the distance conversion of the shooting parameters is carried out to obtain the distance threshold of the current focus support movement; the current focus is moved in the first direction by the first distance to obtain the front focus, and the current focus is The rear focus is obtained by moving the second distance in the second direction, the first direction is opposite to the second direction, and both the first distance and the second distance are less than or equal to the distance threshold.

In one implementation, the processor 701 is configured to: calculate the out-of-focus distance of the camera module 704 according to the aperture value and the diameter of the lens aperture; and calculate the distance supported by the current focus to move according to the out-of-focus distance and the step factor. Threshold.

In an implementation manner, the processor 701 is configured to: perform image recognition on the first frame image, the second frame image, and the third frame image, and calculate the corresponding current focus value, front focus value, and back focus value. The focus value is used to reflect the clarity of the frame image corresponding to the focus value; if the current focus value is between the front focus value and the back focus value, and the front focus value is greater than the back focus value, the camera module 704 is determined The focus adjustment direction of is the first direction from the current focus to the front focus adjustment, and the focus adjustment distance is the distance between the current focus and the front focus; the current focus of the camera module 704 is adjusted to the front focus along the first direction .

In an implementation manner, the processor 701 is configured to: perform image recognition on the first frame image, the second frame image, and the third frame image, and correspondingly calculate the current focus value, the front focus value, and the back focus value. The value is used to reflect the sharpness of the frame image corresponding to the focus value; if the current focus value is between the front focus value and the back focus value, and the front focus value is less than the back focus value, the camera module 704 is determined to be The focus adjustment direction is the second direction of the current focus to the rear focus adjustment, the focus adjustment distance of the camera module 704 is the distance between the current focus and the rear focus; the current focus of the camera module 704 is adjusted along the second direction To the rear focus.

In one implementation, the processor 701 is configured to: perform image recognition on the first frame image, the second frame image, and the third frame image, and correspondingly calculate the current focus value, the front focus value, and the back focus value. The value is used to reflect the sharpness of the frame image corresponding to the focus value; if the current focus value is greater than the front focus value and the rear focus value, it is determined that there is no need to adjust the current focus of the camera module 704, and the focus adjustment direction of the camera module 704 And the focus adjustment distance is empty.

The embodiment of the present application also provides a readable storage medium, and the readable storage medium stores a computer program. When the computer program is executed by a processor, it can be used to implement the description in the embodiment corresponding to FIG. 4 of the embodiment of the present application. The focus adjustment method will not be repeated here.

The computer-readable storage medium may be an internal storage unit of the camera system described in any of the foregoing embodiments, such as a hard disk or memory of a device. The computer-readable storage medium may also be an external storage device of the camera system, such as a plug-in hard disk equipped on the device, a smart memory card (SMC), or a secure digital (SD) Card, Flash Card, etc. Further, the computer-readable storage medium may also include both an internal storage unit of the camera system and an external storage device. The computer-readable storage medium is used to store the computer program and other programs and data required by the camera system. The computer-readable storage medium can also be used to temporarily store data that has been output or will be output.

A person of ordinary skill in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be implemented by instructing relevant hardware through a computer program. The program can be stored in a readable storage medium, and the program can be stored in a readable storage medium. When executed, it may include the procedures of the above-mentioned method embodiments. Wherein, the storage medium may be a magnetic disk, an optical disc, a read-only memory (Read-Only Memory, ROM), or a random access memory (Random Access Memory, RAM), etc.

The above-disclosed are only the preferred embodiments of the application, which of course cannot be used to limit the scope of rights of the application. Therefore, equivalent changes made in accordance with the claims of the application still fall within the scope of the application.

Claims

A focus adjustment method, characterized in that the method includes:

Acquire the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module at the current focus, the front focus, and the back focus, where the current focus is between the front focus and the back focus Between focus

Identifying the first frame image, the second frame image, and the third frame image, and determining the focus adjustment direction and focus adjustment distance of the camera module;

Adjust the current focus of the camera module according to the focus adjustment direction and the focus adjustment distance of the camera module.
The method according to claim 1, characterized in that, before acquiring the first frame image, the second frame image, and the third frame image correspondingly taken by the camera module at the current focus, the front focus, and the back focus, The method also includes:

Determine the front focus and the rear focus captured by the camera module.
The method of claim 2, wherein the determining the front focus and the back focus captured by the camera module comprises:

Acquire the shooting parameters when the camera module is shooting at the current focus, the shooting parameters include the aperture value, the diameter of the lens aperture, and a step factor, and the step factor is used to indicate the camera module within a unit distance The movement step length of the group's lens;

Performing distance conversion on the shooting parameters to obtain a distance threshold for the current focus to support movement;

Move the current focus in a first direction by a first distance to obtain the front focus, move the current focus in a second direction by a second distance to obtain the rear focus, and the first direction is the same as the second The directions are opposite, and the first distance and the second distance are both less than or equal to the distance threshold.
The method of claim 3, wherein the first distance and the second distance are both equal to the distance threshold.
The method according to claim 3, wherein the performing distance conversion on the shooting parameter to obtain the distance threshold for the current focus to support movement comprises:

Calculating the out-of-focus distance of the camera module according to the aperture value and the diameter of the lens aperture;

According to the out-of-focus distance and the step size factor, a distance threshold for the current focus to support movement is calculated.
The method according to any one of claims 1-5, wherein the identifying the first frame image, the second frame image, and the third frame image, and determining the camera module Focus adjustment direction and focus adjustment distance include:

Perform image recognition on the first frame image, the second frame image, and the third frame image, and calculate the corresponding current focus value, front focus value, and back focus value. The focus value is used to reflect The definition of the frame image corresponding to the focus value;

If the current focus value is between the front focus value and the back focus value, and the front focus value is greater than the back focus value, determine the focus adjustment direction of the camera module Is the first direction in which the current focus is adjusted to the front focus, and the focus adjustment distance is the distance between the current focus and the front focus;

The adjusting the current focus of the camera module according to the focus adjustment direction and the focus adjustment distance of the camera module includes: adjusting the current focus of the camera module along the first direction to the front focus.
The method according to any one of claims 1-5, wherein the identifying the first frame image, the second frame image, and the third frame image, and determining the camera module Focus adjustment direction and focus adjustment distance include:

Perform image recognition on the first frame image, the second frame image, and the third frame image, and correspondingly calculate the current focus value, the front focus value, and the back focus value. The focus value is used to reflect all The definition of the frame image corresponding to the focus value;

If the current focus value is between the front focus value and the back focus value, and the front focus value is less than the back focus value, then the focus adjustment direction of the camera module is determined Is the second direction in which the current focus is adjusted to the rear focus, and the focus adjustment distance of the camera module is the distance between the current focus and the rear focus;

The adjusting the current focus of the camera module according to the focus adjustment direction and the focus adjustment distance of the camera module includes: adjusting the current focus of the camera module to the rear position along the second direction focus.
The method according to any one of claims 1-5, wherein the identifying the first frame image, the second frame image, and the third frame image, and determining the camera module Focus adjustment direction and focus adjustment distance include:

Perform image recognition on the first frame image, the second frame image, and the third frame image, and correspondingly calculate the current focus value, the front focus value, and the back focus value. The focus value is used to reflect all The definition of the frame image corresponding to the focus value;

If the current focus value is greater than the front focus value and the rear focus value, it is determined that there is no need to adjust the current focus of the camera module, and the focus adjustment direction and focus adjustment distance of the camera module are both air.
A camera system, characterized in that it comprises a memory and a processor;

The memory is used to store a computer program;

The processor calls the computer program for:

Acquire the first frame image, the second frame image, and the third frame image correspondingly captured by the camera module at the current focus, the front focus, and the back focus, where the current focus is between the front focus and the back focus Between focus

Identifying the first frame image, the second frame image, and the third frame image, and determining the focus adjustment direction and focus adjustment distance of the camera module;

Adjust the current focus of the camera module according to the focus adjustment direction and the focus adjustment distance of the camera module.
A computer-readable storage medium, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed, the focus adjustment method according to any one of claims 1-7 is realized .