CN107454343A - Photographic method, camera arrangement and terminal - Google Patents

Abstract

The invention is applicable to the field of mobile communication, and provides a photographing method, a photographing device and a terminal. The method includes: performing photometry on the scene to be photographed by the first camera; determining the exposure time of the brightest area overexposed according to the photometry result; determining the exposure time of the first camera according to the determined overexposed exposure time of the brightest area And the exposure time of the second camera, the exposure time of the first camera is not equal to the exposure time of the second camera; according to the determined exposure time of the first camera and the determined exposure time of the second camera, through the first camera and The second camera simultaneously takes photos of the scene to be photographed; and synthesizes the photo obtained by the first camera of the scene to be photographed and the photo obtained by the second camera of the scene to be photographed. The embodiment of the present invention can output high dynamic photos.

Description

Photographing method, photographing device and terminal

technical field

The invention belongs to the field of mobile communication, and in particular relates to a photographing method, photographing device and terminal.

Background technique

At present, more and more functions are integrated in the terminal (smart phone or tablet computer). For example, in addition to the Internet access function, the camera function can also be realized by setting a camera on the terminal.

However, when shooting scenes with large brightness differences through the existing cameras installed on the terminal, it is easy to overexpose in high-brightness areas and easy to underexpose in low-brightness areas. Because the dynamic range of the captured photos is too small, As a result, the photos taken are not good.

Contents of the invention

Embodiments of the present invention provide a photographing method, a photographing device, and a terminal, aiming at solving the problem that it is difficult to obtain photographs with a large dynamic range of brightness in existing methods.

On the one hand, provide a kind of photographing method, described method comprises the following steps:

Meter the scene to be photographed through the first camera;

Determine the exposure time for the brightest area to be overexposed according to the metering result;

Determine the exposure time of the first camera and the exposure time of the second camera according to the determined overexposed exposure time of the brightest area, and the exposure time of the first camera is not equal to the exposure time of the second camera;

According to the determined exposure time of the first camera and the determined exposure time of the second camera, the scene to be photographed is simultaneously photographed by the first camera and the second camera;

A photo obtained by taking pictures of the scene to be photographed by the first camera and a photo obtained by taking photos of the scene to be photographed by the second camera are synthesized.

With reference to the first aspect, in the first possible implementation manner of the first aspect, the step of using the first camera to measure the light of the scene to be photographed specifically includes:

Obtain the photo corresponding to the scene to be photographed through the first camera;

Divide the acquired photos into N*N regions, where N is a natural number;

The luminance values of the pixels in the divided areas are counted to determine the highest luminance value and the area where the highest luminance value is located.

With reference to the first possible implementation of the first aspect, in the second possible implementation of the first aspect, the step of determining the overexposed exposure time of the brightest area according to the photometry result specifically includes:

Obtain the brightness level of the sensor of the first camera;

According to the determined highest brightness value, the exposure time for obtaining the highest brightness value, and the acquired brightness level, the exposure time for overexposure of the brightest area is determined.

In combination with the first aspect, or the first possible implementation of the first aspect, or the second possible implementation of the first aspect, in the third possible implementation of the first aspect, the determined according to The steps of determining the exposure time of the first camera and the exposure time of the second camera specifically include:

Using the exposure time T of the brightest area overexposed as the exposure time T of the first camera, the T is greater than 0;

T/M is adopted as the exposure time of the second camera, and the M is a natural number greater than or equal to 2 and less than or equal to 10.

With reference to the third possible implementation of the first aspect, in the fourth possible implementation of the first aspect, the synthesis of the photos obtained by taking pictures of the scenes to be taken by the first camera and the pictures to be taken by the second camera The steps of taking pictures of the scenes to obtain the photos specifically include:

Determine the overexposure area in the photo taken by the first camera;

cropping said determined overexposed area;

Combining the area corresponding to the trimmed over-exposure area in the photo taken by the second camera with the trimmed photo of the over-exposure area to obtain a synthesized photo.

In a second aspect, a camera device is provided, the device comprising:

The scene light metering unit is used to measure the light of the scene to be photographed through the first camera;

an overexposure exposure time determining unit, configured to determine the overexposure exposure time of the brightest area according to the photometry result;

The exposure time determining unit of the camera is used to determine the exposure time of the first camera and the exposure time of the second camera according to the determined overexposure time of the brightest area, and the exposure time of the first camera is not equal to the exposure time of the second camera time;

The photographing unit is used to simultaneously take photographs of the scene to be photographed through the first camera and the second camera according to the determined exposure time of the first camera and the determined exposure time of the second camera;

The photo synthesis unit is configured to synthesize the photo obtained by taking pictures of the scene to be photographed by the first camera and the photo obtained by taking photos of the scene to be photographed by the second camera.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the scene light metering unit includes:

The photo acquisition module is used to obtain the photo corresponding to the scene to be photographed through the first camera;

The photo division module is used to divide the acquired photos into N*N regions, where N is a natural number;

The highest luminance value determination module is configured to count the luminance values of the pixels in the divided area to determine the highest luminance value and the area where the highest luminance value is located.

With reference to the first possible implementation manner of the second aspect, in a second possible implementation manner of the second aspect, the overexposure exposure time determining unit includes:

A brightness level acquisition module, configured to acquire the brightness level of the sensor of the first camera;

The exposure time determining module for overexposure of the brightest area is configured to determine the exposure time for overexposure of the brightest area according to the determined highest brightness value, the exposure time for obtaining the highest brightness value, and the acquired brightness level.

In combination with the second aspect, or the first possible implementation of the second aspect, or the second possible implementation of the second aspect, in a third possible implementation of the second aspect, the exposure of the camera The timing unit consists of:

The exposure time determination module of the first camera is used to adopt the exposure time T of the brightest area overexposed as the exposure time T of the first camera, and the T is greater than 0;

The exposure time determination module of the second camera is configured to use T/M as the exposure time of the second camera, where M is a natural number greater than or equal to 2 and less than or equal to 10.

With reference to the third possible implementation manner of the second aspect, in a fourth possible implementation manner of the second aspect, the photo synthesis unit includes:

An overexposure area determination module, configured to determine the overexposure area in the photo obtained by the first camera;

an over-exposure area cutting module, configured to cut the determined over-exposure area;

The image synthesis module is used to synthesize the area corresponding to the clipped over-exposure area in the photo taken by the second camera with the photo with the clipped over-exposure area to obtain the synthesized photo.

In a third aspect, a terminal is provided, and the terminal includes the above-mentioned photographing device.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the terminal is a smart phone or a tablet computer.

In the embodiment of the present invention, the scene to be photographed is metered by the first camera, the exposure time of the brightest area is determined according to the photometry result, and the exposure time of the first camera is determined according to the determined exposure time of the brightest area. The exposure time and the exposure time of the second camera, according to the determined exposure time of the first camera and the determined exposure time of the second camera, simultaneously take pictures of the scene to be shot, and synthesize the first camera to take pictures of the scene to be shot The obtained photo and the photo obtained by taking pictures of the scene to be photographed by the second camera. Since the scene to be shot is metered, the exposure time of the brightest area in the scene to be shot can be determined, so that the exposure time of the first camera and the second camera can be determined according to the exposure time of the brightest area. And shoot the same scene at the same time according to the determined exposure time, and because the exposure time of the first camera and the exposure time of the second camera are different, after combining the photos taken by the first camera and the photos taken by the second camera, Higher dynamic photos can be obtained, so that scenes with large brightness differences can be clearly presented.

Description of drawings

Fig. 1 is a flowchart of a photographing method provided by the first embodiment of the present invention;

Fig. 2 is a structural diagram of a photographing device provided by a second embodiment of the present invention.

detailed description

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

In the embodiment of the present invention, the scene to be photographed is metered by the first camera, the exposure time of the brightest area is determined according to the photometry result, and the exposure time of the first camera is determined according to the determined exposure time of the brightest area. time and the exposure time of the second camera, according to the determined exposure time of the first camera and the determined exposure time of the second camera, the scene to be shot is taken at the same time, and the scene to be shot is synthesized by the first camera to obtain The photo and the photo obtained by taking pictures of the scene to be shot by the second camera.

In order to illustrate the technical solutions of the present invention, specific examples are used below to illustrate.

Embodiment one:

Fig. 1 shows a flow chart of a photographing method provided by the first embodiment of the present invention. In the embodiment of the present invention, two cameras are arranged on the same surface of the terminal: a first camera and a second camera. The same scene is captured by the first camera and the second camera at the same time, and two photos with different exposure levels are obtained, and then the final photo is synthesized based on the two obtained two photos with different exposure levels. The details are as follows:

Step S11 , metering the scene to be photographed through the first camera.

Before the photometry of the first camera, the parameters of the first camera and the second camera can be adjusted to ensure that the field angles of the first camera and the second camera are the same, so that the first camera and the second camera can capture the same scene, which is beneficial to the subsequent photo synthesis.

Wherein, the step S11, the step of measuring the scene to be photographed through the first camera specifically includes:

A1. Obtain the photo corresponding to the scene to be photographed through the first camera. Specifically, a scene is photographed by the first camera, and then a photo corresponding to the scene is acquired.

A2. Divide the acquired photos into N*N areas, where N is a natural number. Dividing the acquired photo into multiple regions is beneficial for analyzing the coordinates of the bright and dark parts of the photo. Wherein, N is a natural number, which can take a value of 4. When N=4, the acquired photo is divided into 16 regions. Of course, N can also take other values, which are not limited here.

A3. Count the luminance values of the pixels in the divided areas to determine the highest luminance value and the area where the highest luminance value is located. Specifically, the brightness value of a pixel can be directly read from the exposed photo. Wherein, the highest luminance value in this step may be the highest luminance value of a pixel, or may be the highest luminance value of average brightness values of pixels included in the divided area. When the highest brightness value is the highest brightness value of the pixel, it can be determined by comparing the brightness values of the pixels one by one; The average value of the luminance values of the pixels included in the area is determined by comparing the average values of the luminance values of each area obtained.

Step S12, determining the exposure time for overexposure of the brightest area according to the photometry result.

The brightest area in this step is also the brightest area in the scene to be photographed.

Wherein, the step S12, the step of determining the exposure time of the brightest area overexposed according to the photometry result specifically includes:

B1. Obtain the brightness level of the sensor of the first camera. Each camera sensor has its corresponding brightness level, the higher the brightness level, the greater the corresponding maximum brightness value. For example, assuming that the brightness level of the sensor of the first camera is 10, the brightness value range of the photos taken by the first camera is 0-1024.

B2. Determine the exposure time for overexposure of the brightest area according to the determined highest brightness value, the exposure time for obtaining the highest brightness value, and the acquired brightness level. Specifically, the ratio of the determined highest brightness value to the exposure time for obtaining the highest brightness value is proportional to the ratio of the maximum brightness value corresponding to the obtained brightness level to the exposure time for over-exposing the brightest area. For example, assuming that the brightness level of the sensor of the first camera is 10, when the brightness level is 10, the corresponding highest brightness value is 1024. Assuming that the determined highest brightness value is 500 (the "500" can refer to the pixel value of a pixel point, or the average value of the pixel value of an area), and the exposure time of "500" is 50ms, then 500/50= 1024X, when the "500" refers to the pixel value of the pixel point, the overexposure exposure time of the area where the pixel point corresponding to the highest brightness value "500" is: X=102.4ms. When the "500" refers to the average value of the pixel values in the area, the overexposure exposure time of the area corresponding to the highest brightness value "500" is: X=102.4ms.

Step S13, determining the exposure time of the first camera and the exposure time of the second camera according to the determined exposure time of overexposure of the brightest area, the exposure time of the first camera is not equal to the exposure time of the second camera.

In this step, in order to obtain high-dynamic photos, the exposure time of the first camera is generally different from the exposure time of the second camera.

Optionally, the exposure time of the first camera can be made longer than the exposure time of the second camera. At this time, the step S13 determines the exposure time of the first camera and the exposure time of the second camera according to the determined overexposed exposure time of the brightest area. The steps of the exposure time specifically include:

C1. Use the exposure time T of the brightest area overexposed as the exposure time T of the first camera, where T is greater than 0. For example, assuming that the exposure time for overexposure of the brightest area is 100 ms, the exposure time of the first camera is also set to 100 ms.

C2. Using T/M as the exposure time of the second camera, where M is a natural number greater than or equal to 2 and less than or equal to 10.

In step S14, according to the determined exposure time of the first camera and the determined exposure time of the second camera, the scene to be photographed is simultaneously photographed by the first camera and the second camera.

In this step, when the exposure time of the first camera is the determined exposure time for overexposure of the brightest area, the dark area can be photographed with the highest brightness, but the brightest area can be overexposed or close to overexposed Brightness (that is, the brightness that is whitish and unclear when photographed). When the exposure time of the second camera is shorter than the exposure time of the first camera (decreased by multiples), the second camera can capture the brightest area clearly and brightly without overexposure.

Step S15, synthesizing the photo obtained by taking pictures of the scene to be photographed by the first camera and the photo obtained by taking photos of the scene to be photographed by the second camera.

In this step, the non-brightest area captured by the first camera and the brightest area captured by the second camera are synthesized into a new photo.

Optionally, in the step S15, the step of synthesizing the photo obtained by taking pictures of the scene to be photographed by the first camera and the photo obtained by taking photos of the scene to be photographed by the second camera specifically includes:

D1. Determine the overexposure area in the photo taken by the first camera. When the brightness value of a pixel is greater than or close to the maximum brightness value set for the pixel (for example, when the brightness level is 10, the maximum brightness value set for the pixel is 1024), indicating that the pixel is overexposed. In this step, first obtain the brightness value of the pixel point obtained by taking pictures, and then compare the brightness value of the pixel point with the highest brightness value set for the pixel point, if the difference between the two is within a threshold range, then determine The pixel is overexposed, that is, it is determined that the area where the pixel is located is overexposed. Wherein, the area where the pixel points are located refers to a certain area in the area divided in step A2.

D2. Clipping the determined overexposure area. Specifically, the determined overexposure area is trimmed according to the boundary of the area divided in step A2.

D3. Synthesizing the area corresponding to the clipped over-exposed area in the photo taken by the second camera with the photo with the clipped over-exposed area to obtain a composited photo. Specifically, determine the area corresponding to the area that needs to be trimmed in the photo taken by the first camera in the photo taken by the second camera, and then compare the determined area with the photo taken by the first camera and cut the overexposed area. Synthesize to get the final photo and output it. For example, suppose the photos taken by the first camera are divided into Y1~Y16 areas, the photos taken by the second camera are divided into Z1~Z16 areas, and the two areas Y1 and Y2 in the photos taken by the first camera are overexposed areas , Z1 and Z2 (corresponding to Y1 and Y2 respectively) in the photo taken by the second camera are combined with Y3-Y16 in the photo taken by the first camera to obtain the final photo.

In the first embodiment of the present invention, the scene to be photographed is metered by the first camera, and the exposure time of the brightest area overexposed is determined according to the photometry result, and the first exposure time of the brightest area is determined according to the determined exposure time of the brightest area The exposure time of the camera and the exposure time of the second camera, according to the determined exposure time of the first camera and the determined exposure time of the second camera, simultaneously take pictures of the scenes to be photographed, and synthesize the scene to be photographed by the first camera The photos obtained by taking photos and the photos obtained by taking photos of the scene to be shot by the second camera. Since the scene to be shot is metered, the exposure time of the brightest area in the scene to be shot can be determined, so that the exposure time of the first camera and the second camera can be determined according to the exposure time of the brightest area. And shoot the same scene at the same time according to the determined exposure time, and because the exposure time of the first camera and the exposure time of the second camera are different, after combining the photos taken by the first camera and the photos taken by the second camera, Higher dynamic photos can be obtained, so that scenes with large brightness differences can be clearly presented.

It should be understood that in the embodiment of the present invention, the sequence numbers of the above-mentioned processes do not mean the order of execution, and the execution order of each process should be determined by its function and internal logic, rather than the implementation process of the embodiment of the present invention. constitute any limitation.

Embodiment two:

FIG. 2 shows a structural diagram of a photographing device provided by a second embodiment of the present invention. The photographing device can be applied to a terminal, and the terminal can include a radio access network (RAN) for communicating with one or more core networks. User equipment, which may be a mobile phone (or "cellular" phone), a computer with a mobile device, etc. For example, the user equipment may also be a portable, pocket, hand-held, computer-built-in, or vehicle-mounted mobile device , which exchange voice and/or data with the radio access network. For another example, the terminal may include a smart phone, a tablet computer, a personal digital assistant PDA, a sales terminal POS, or a vehicle-mounted computer.

The photographing device includes: a scene metering unit 21 , an overexposure exposure time determination unit 22 , a camera exposure time determination unit 23 , a photographing unit 24 , and a photo synthesis unit 25 . in:

The scene light metering unit 21 is configured to measure the light of the scene to be photographed through the first camera.

Wherein, the scene light metering unit 21 includes:

The photo acquisition module is configured to acquire the photo corresponding to the scene to be photographed through the first camera. Specifically, a scene is photographed by the first camera, and then a photo corresponding to the scene is acquired.

The photo division module is used to divide the obtained photos into N*N regions, where N is a natural number. Wherein, N is a natural number, which can take a value of 4. When N=4, the acquired photo is divided into 16 regions. Of course, N can also take other values, which are not limited here.

The highest luminance value determination module is configured to count the luminance values of the pixels in the divided area to determine the highest luminance value and the area where the highest luminance value is located. Wherein, the highest luminance value may be the highest luminance value of a pixel, or may be the highest luminance value of average brightness values of pixels included in the divided area. When the highest brightness value is the highest brightness value of the pixel, it can be determined by comparing the brightness values of the pixels one by one; The average value of the luminance values of the pixels included in the area is determined by comparing the average values of the luminance values of each area obtained.

The overexposure exposure time determining unit 22 is configured to determine the overexposure exposure time of the brightest area according to the photometry result.

Wherein, the brightest area is the brightest area in the scene to be photographed.

Wherein, the exposure time determining unit 22 of the overexposure includes:

The brightness level acquiring module is configured to acquire the brightness level of the sensor of the first camera. Each camera sensor has its corresponding brightness level, the higher the brightness level, the greater the corresponding maximum brightness value.

The exposure time determining module for overexposure of the brightest area is configured to determine the exposure time for overexposure of the brightest area according to the determined highest brightness value, the exposure time for obtaining the highest brightness value, and the acquired brightness level. Specifically, the ratio of the determined highest brightness value to the exposure time for obtaining the highest brightness value is proportional to the ratio of the maximum brightness value corresponding to the obtained brightness level to the exposure time for over-exposing the brightest area.

The exposure time determination unit 23 of the camera is configured to determine the exposure time of the first camera and the exposure time of the second camera according to the determined overexposed exposure time of the brightest area, and the exposure time of the first camera is not equal to the exposure time of the second camera. exposure time.

Wherein, when the exposure time of the first camera is greater than the exposure time of the second camera, the exposure time determination unit 23 of the camera includes:

The exposure time determining module of the first camera is configured to use the exposure time T of the brightest area overexposed as the exposure time T of the first camera, where T is greater than 0.

The exposure time determination module of the second camera is configured to use T/M as the exposure time of the second camera, where M is a natural number greater than or equal to 2 and less than or equal to 10.

The photographing unit 24 is configured to simultaneously photograph the scene to be photographed through the first camera and the second camera according to the determined exposure time of the first camera and the determined exposure time of the second camera.

When the exposure time of the first camera is the exposure time determined to overexpose the brightest area, the highest brightness can be taken in the dark area, but the brightest area can be overexposed or close to the overexposed brightness (ie into a whitish, unclear brightness). When the exposure time of the second camera is shorter than the exposure time of the first camera (decreased by multiples), the second camera can capture the brightest area clearly and brightly without overexposure.

The photo synthesis unit 25 is configured to synthesize a photo obtained by taking pictures of the scene to be photographed by the first camera and a photo obtained by taking photos of the scene to be photographed by the second camera.

Wherein, the photo synthesis unit 25 includes:

The overexposure area determination module is used to determine the overexposure area in the photo taken by the first camera. Specifically, first obtain the brightness value of the pixel point obtained by taking pictures, and then compare the brightness value of the pixel point with the highest brightness value set for the pixel point, and if the difference between the two is within a threshold range, the pixel is determined to be Point overexposure means that the area where the pixel is located is determined to be overexposed. Wherein, the area where the pixel points are located refers to a certain area in the area divided in step A2.

The over-exposure area cutting module is used for cutting the determined over-exposure area.

The image synthesis module is used to synthesize the area corresponding to the clipped over-exposure area in the photo taken by the second camera with the photo with the clipped over-exposure area to obtain the synthesized photo. Specifically, determine the area corresponding to the area that needs to be trimmed in the photo taken by the first camera in the photo taken by the second camera, and then compare the determined area with the photo taken by the first camera and cut the overexposed area. Synthesize to get the final photo and output it.

In the second embodiment of the present invention, since the scene to be photographed is metered, the exposure time of the brightest area in the scene to be photographed can be determined, so that the first exposure time can be determined according to the exposure time of the brightest area. The exposure time of the camera and the second camera, and shoot the same scene at the same time according to the determined exposure time, and because the exposure time of the first camera is different from the exposure time of the second camera, the photos taken by the first camera and the second camera After the photos taken by the two cameras are synthesized, more dynamic photos can be obtained, so that scenes with large brightness differences can be clearly presented.

Those skilled in the art can appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

Those skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the above-described system, device and unit can refer to the corresponding process in the foregoing method embodiment, which will not be repeated here.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices and methods may be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or May be integrated into another system, or some features may be ignored, or not implemented. In another point, the mutual coupling or direct coupling or communication connection shown or discussed may be through some interfaces, and the indirect coupling or communication connection of devices or units may be in electrical, mechanical or other forms.

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

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, each unit may exist separately physically, or two or more units may be integrated into one unit.

If the functions described above are realized in the form of software function units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the essence of the technical solution of the present invention or the part that contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including Several instructions are used to make a computer device (which may be a personal computer, a server, or a network device, etc.) execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), magnetic disk or optical disk and other media that can store program codes. .

The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Anyone skilled in the art can easily think of changes or substitutions within the technical scope disclosed in the present invention. Should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims (10)

1. A method for taking pictures, characterized in that the method comprises: Meter the scene to be photographed through the first camera; Determine the exposure time for the brightest area to be overexposed according to the metering result; Determine the exposure time of the first camera and the exposure time of the second camera according to the determined overexposed exposure time of the brightest area, and the exposure time of the first camera is not equal to the exposure time of the second camera; According to the determined exposure time of the first camera and the determined exposure time of the second camera, the scene to be photographed is simultaneously photographed by the first camera and the second camera; Synthesizing the photo obtained by taking pictures of the scene to be shot by the first camera and the photo obtained by taking pictures of the scene to be shot by the second camera; The photometry of the scene to be photographed by the first camera specifically includes: Obtain the photo corresponding to the scene to be photographed through the first camera; Divide the acquired photos into N*N regions, where N is a natural number; The luminance values of the pixels in the divided areas are counted to determine the highest luminance value and the area where the highest luminance value is located. 2. The method according to claim 1, wherein the determining the overexposed exposure time of the brightest area according to the photometry results specifically comprises: Obtain the brightness level of the sensor of the first camera; According to the determined highest brightness value, the exposure time for obtaining the highest brightness value, and the acquired brightness level, the exposure time for overexposure of the brightest area is determined. 3. The method according to claim 1 or 2, wherein the determining the exposure time of the first camera and the exposure time of the second camera according to the determined overexposed exposure time of the brightest area specifically includes: Using the exposure time T of the brightest area overexposed as the exposure time T of the first camera, the T is greater than 0; T/M is adopted as the exposure time of the second camera, and the M is a natural number greater than or equal to 2 and less than or equal to 10. 4. The method according to claim 3, wherein said synthesizing the photo obtained by taking pictures of the scene to be photographed by the first camera and the photo obtained by photographing the scene to be photographed by the second camera specifically includes: Determine the overexposure area in the photo taken by the first camera; cropping said determined overexposed area; Combining the area corresponding to the trimmed over-exposure area in the photo taken by the second camera with the trimmed photo of the over-exposure area to obtain a synthesized photo. 5. A camera device, characterized in that the device comprises: The scene light metering unit is used to measure the light of the scene to be photographed through the first camera; an overexposure exposure time determining unit, configured to determine the overexposure exposure time of the brightest area according to the photometry result; The exposure time determining unit of the camera is used to determine the exposure time of the first camera and the exposure time of the second camera according to the determined overexposure time of the brightest area, and the exposure time of the first camera is not equal to the exposure time of the second camera time; The photographing unit is used to simultaneously take photographs of the scene to be photographed through the first camera and the second camera according to the determined exposure time of the first camera and the determined exposure time of the second camera; The photo synthesis unit is used for synthesizing the photo obtained by taking pictures of the scene to be taken by the first camera and the photo obtained by taking pictures of the scene to be taken by the second camera; The scene light metering unit includes: The photo acquisition module is used to obtain the photo corresponding to the scene to be photographed through the first camera; The photo division module is used to divide the obtained photos into N*N regions, where N is a natural number; The highest luminance value determination module is configured to count the luminance values of the pixels in the divided area to determine the highest luminance value and the area where the highest luminance value is located. 6. The device according to claim 5, wherein the overexposure exposure time determining unit comprises: A brightness level acquisition module, configured to acquire the brightness level of the sensor of the first camera; The exposure time determining module for overexposure of the brightest area is configured to determine the exposure time for overexposure of the brightest area according to the determined highest brightness value, the exposure time for obtaining the highest brightness value, and the acquired brightness level. 7. The device according to claim 5 or 6, wherein the exposure time determining unit of the camera comprises: The exposure time determination module of the first camera is used to adopt the exposure time T of the brightest area overexposed as the exposure time T of the first camera, and the T is greater than 0; The exposure time determination module of the second camera is configured to use T/M as the exposure time of the second camera, where M is a natural number greater than or equal to 2 and less than or equal to 10. 8. The device according to claim 7, wherein the photo synthesis unit comprises: An overexposure area determination module, configured to determine the overexposure area in the photo obtained by the first camera; an over-exposure area cutting module, configured to cut the determined over-exposure area; The image synthesis module is used to synthesize the area corresponding to the clipped over-exposure area in the photo taken by the second camera with the photo with the clipped over-exposure area to obtain the synthesized photo. 9. A terminal, characterized in that the terminal comprises the photographing device according to any one of claims 5 to 8. 10. The terminal according to claim 9, wherein the terminal is a smart phone or a tablet computer.