CN109005369B

CN109005369B - Exposure control method, exposure control device, electronic apparatus, and computer-readable storage medium

Info

Publication number: CN109005369B
Application number: CN201811230259.XA
Authority: CN
Inventors: 张弓
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2018-10-22
Filing date: 2018-10-22
Publication date: 2020-07-10
Anticipated expiration: 2038-10-22
Also published as: CN109005369A

Abstract

The application provides an exposure control method, an exposure control device, an electronic device and a computer-readable storage medium, wherein the method comprises the following steps: the method comprises the steps of performing photometry to determine the target exposure of each frame of image to be collected, determining the exposure duration of each frame of image to be collected according to the target exposure of each frame of image to be collected and the preset light sensitivity of each frame of image to be collected, reducing the exposure duration and correspondingly increasing the light sensitivity for at least one frame of image to be collected, wherein the exposure duration is greater than the upper limit of the duration, setting the light sensitivity of at least one frame of image to be collected as the upper limit of the light sensitivity if the increased light sensitivity is greater than the upper limit of the light sensitivity, and finally performing exposure control according to the exposure duration and the light sensitivity of each frame of image to be collected.

Description

Exposure control method, exposure control device, electronic apparatus, and computer-readable storage medium

Technical Field

The present application relates to the field of imaging technologies, and in particular, to an exposure control method and apparatus, an electronic device, and a computer-readable storage medium.

Background

With the development of intelligent terminal technology, the use of mobile terminal devices (such as smart phones, tablet computers, and the like) is becoming more and more popular. Most mobile terminal devices are internally provided with a camera, and with the enhancement of the processing capability of the mobile terminal and the development of the camera technology, the performance of the built-in camera is stronger and stronger, the requirements of people on the shooting quality are higher and higher, and people hope to obtain high-quality imaging even at night with harsh shooting conditions.

At present, due to professional level limitation, people do not know how to set appropriate shooting parameters according to a shooting scene, the built-in shooting parameters of a camera are single, the complex and changeable night scene environment cannot be met, especially when the ambient light is dark, a high light sensitivity ISO value is generally set for achieving the target brightness, but the image is caused to have large noise or heavy image smearing, and the imaging image quality is low.

Disclosure of Invention

The present application is directed to solving, at least to some extent, one of the technical problems in the related art.

Therefore, the present application provides an exposure control method, an exposure control device, an electronic apparatus, and a computer-readable storage medium, so as to solve the technical problem in the related art that when shooting a night scene, in order to achieve target brightness, sensitivity is generally set to be higher, which results in larger noise in an imaged image and lower quality of the imaged image.

The application provides an exposure control device.

The application provides an electronic device.

The present application provides a computer-readable storage medium.

An embodiment of an aspect of the present application provides an exposure control method, including:

metering light to determine the target exposure of each frame of image to be acquired;

determining the exposure duration of each frame of image to be acquired according to the target exposure of each frame of image to be acquired and the preset light sensitivity of each frame of image to be acquired;

for at least one frame of image to be acquired, of which the exposure time length is greater than the upper limit of the time length, in each frame of image to be acquired, reducing the exposure time length and correspondingly increasing the sensitivity according to the upper limit of the time length;

if the increased sensitivity is greater than the upper sensitivity limit, setting the sensitivity of the at least one frame of image to be collected as the upper sensitivity limit;

and carrying out exposure control according to the exposure time and the light sensitivity of the image to be acquired of each frame.

In another aspect of the present application, an embodiment provides an exposure control apparatus, including:

the light metering module is used for metering light to determine the target exposure of each frame of image to be collected;

the determining module is used for determining the exposure duration of each frame of image to be acquired according to the target exposure of each frame of image to be acquired and the preset light sensitivity of each frame of image to be acquired;

the first updating module is used for reducing the exposure time and correspondingly increasing the sensitivity of at least one frame of image to be acquired, of which the exposure time is greater than the upper limit of the time length, in each frame of image to be acquired;

the second updating module is used for setting the sensitivity of the at least one frame of image to be collected as the upper limit of the sensitivity if the increased sensitivity is greater than the upper limit of the sensitivity;

and the control module is used for carrying out exposure control according to the exposure duration and the light sensitivity of each frame of image to be acquired.

An embodiment of another aspect of the present application provides an electronic device, including: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the exposure control method as described in the above embodiments when executing the program.

In yet another aspect, the present application provides a computer-readable storage medium, on which a computer program is stored, wherein the computer program is executed by a processor to implement the exposure control method according to the above embodiments.

The technical scheme provided by the embodiment of the application can have the following beneficial effects:

determining the target exposure of each frame of image to be acquired through photometry, determining the exposure time of each frame of image to be acquired according to the target exposure of each frame of image to be acquired and the preset sensitivity of each frame of image to be acquired, reducing the exposure time and correspondingly increasing the sensitivity of at least one frame of image to be acquired with the exposure time being greater than the upper limit of the time in each frame of image to be acquired, setting the sensitivity of at least one frame of image to be acquired as the upper limit of the sensitivity if the increased sensitivity is greater than the upper limit of the sensitivity, and finally carrying out exposure control according to the exposure time and the sensitivity of each frame of image to be acquired. Therefore, the exposure time of each frame of image to be acquired is determined through photometry, and the light sensitivity is dynamically adjusted according to the adjustment of the exposure time, so that imaging is realized, the dynamic range of the image shot in the night scene shooting mode is improved, the noise in the shot image is effectively inhibited, and the quality of the image shot in the night scene is improved.

Drawings

The foregoing and/or additional aspects and advantages of the present application will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings of which:

fig. 1 is a schematic flowchart of an exposure control method according to an embodiment of the present disclosure;

fig. 2 is a schematic flowchart of another exposure control method according to an embodiment of the present disclosure;

FIG. 3 is a flowchart illustrating another exposure control method according to an embodiment of the present application

Fig. 4 is a schematic structural diagram of an exposure control apparatus according to an embodiment of the present disclosure;

FIG. 5 is a block diagram of an electronic device according to some embodiments of the present application;

FIG. 6 is a block diagram of an image processing circuit according to some embodiments of the present disclosure.

Detailed Description

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are exemplary and intended to be used for explaining the present application and should not be construed as limiting the present application.

In the related art, for a mobile terminal device with a small aperture, when an image is shot in a night scene, because light is dark, if the brightness is improved by increasing the exposure time of the image to be collected, the shot image may have smear due to shaking; if the sensitivity value is increased to acquire an image, noise is introduced during photographing, resulting in blurring of the image. Therefore, the images shot in the night scene are low in dynamic range and overall brightness, high in noise level, prone to ghost and blur and prone to affecting user experience.

In view of the above problems, an embodiment of the present application provides an exposure control method, which determines a target exposure amount of each frame of an image to be acquired through photometry, determines an exposure duration of each frame of the image to be acquired according to the target exposure amount of each frame of the image to be acquired and a preset sensitivity of each frame of the image to be acquired, reduces the exposure duration and correspondingly increases the sensitivity for at least one frame of the image to be acquired, in which the exposure duration is greater than an upper limit of the duration, according to the upper limit of the duration, sets the sensitivity of the at least one frame of the image to be acquired as an upper limit of the sensitivity, and finally performs exposure control according to the exposure duration and the sensitivity of each frame of the image to be acquired.

An exposure control method, an apparatus, an electronic device, and a computer-readable storage medium of the embodiments of the present application are described below with reference to the drawings.

Fig. 1 is a schematic flowchart of an exposure control method according to an embodiment of the present disclosure.

The exposure control method is applied to electronic equipment, and the electronic equipment can be hardware equipment with various operating systems and imaging equipment, such as a mobile phone, a tablet personal computer, a personal digital assistant and a wearable device.

As shown in fig. 1, the exposure control method includes the steps of:

step 101, light is measured to determine the target exposure of each frame of image to be acquired.

The exposure amount refers to how much a photosensitive device in the imaging apparatus receives light within an exposure time, and the exposure amount is related to an aperture, the exposure time, and sensitivity. Wherein, the aperture, namely the clear aperture, determines the quantity of light passing in unit time; the exposure duration refers to the time when light passes through the lens; the sensitivity, also called ISO value, is an index for measuring the sensitivity of the negative film to light, and is used for representing the photosensitive speed of the photosensitive element, and the higher the ISO value is, the stronger the photosensitive capability of the photosensitive element is.

It should be noted that when the sensitivity of the imaging apparatus is low, it takes longer exposure time to achieve the same imaging effect as when the sensitivity is high. The sensitivity of a digital camera is an index similar to the sensitivity of a film, and the ISO value of a digital camera can be adjusted by adjusting the sensitivity of a photosensitive device or combining photosensitive points, that is, the ISO value can be increased by increasing the light sensitivity of a photosensitive device or combining several adjacent photosensitive points. Of course, using a relatively high sensitivity generally introduces more noise in order to reduce the exposure time, which can result in reduced image quality. Therefore, in a night scene, in order to obtain a better noise suppression effect, it is desirable to set a lower sensitivity, such as 100ISO or 200ISO, and at the same time, since the aperture of an electronic device such as a mobile phone is usually fixed, it is necessary to increase the exposure time, i.e., the shutter time, accordingly.

Specifically, a preview image of a current shooting scene is acquired through imaging equipment, the ambient light brightness of each area of the preview image is further obtained through measurement of a photosensitive device, and then the reference exposure is determined according to the brightness information of the preview image. In the case where the aperture is fixed, the reference exposure amount may specifically include a reference exposure time period and a reference sensitivity.

In the embodiment of the present application, the reference exposure amount is an exposure amount that is determined according to the luminance information of the current shooting scene, which is obtained by performing photometry on the preview image. The value of the reference exposure may be a product of the reference sensitivity and the reference exposure time period

The reference sensitivity may be a sensitivity that is determined according to the current shake degree of the imaging apparatus and is suitable for the current shake degree, or may be a sensitivity obtained by photometry, which is not limited in this embodiment. It can be understood that, because the exposure and the sensitivity affect the overall shooting duration, if the shooting duration is too long, the shake degree of the imaging device may be increased during the handheld shooting, and the image quality may be affected. Therefore, when the reference sensitivity is determined according to the current degree of shake of the imaging apparatus, the photographing time period should be controlled within an appropriate range.

Specifically, since the exposure amount is related to the aperture, the exposure time period, and the sensitivity, when the size of the aperture is fixed, the reference exposure time period can be determined from the reference exposure amount and the reference sensitivity. And taking the reference exposure time length as EV0, and determining the target exposure of each frame of image to be acquired according to the preset exposure compensation value of each frame of image to be acquired.

The preset Exposure compensation Value is an Exposure Value (EV) that is determined according to the content of the preview screen that the current shooting scene belongs to the night scene and is preset according to the ambient light brightness of the current shooting scene. In the initial definition of exposure value, exposure value does not mean an exact numerical value, but means "a combination of all camera apertures and exposure periods that can give a uniform exposure amount". The sensitivity, aperture and exposure time determine the exposure of the camera, and different combinations of parameters can produce equal exposures, i.e. the EV values of these different combinations are the same, e.g. using an 1/125 second exposure time and f11 aperture combination and using a 1/250 second exposure time and f8 shutter combination, the exposure obtained is the same, i.e. the EV values are the same, with the same sensitivity. Generally, the exposure amount corresponding to the EV value of 0is taken as the basic exposure amount, the exposure amount is increased by one step, that is, the exposure time is increased by one time, or the sensitivity is increased by one time, or the aperture is increased by one step, and the EV value is increased by 1, that is, the exposure amount corresponding to the EV1 is twice the exposure amount corresponding to the EV 0.

As an example, if the imaging apparatus determines that the reference exposure amount of the image to be captured for each frame is 400 from the measured brightness information of the preview image, and the reference sensitivity ISO value is 100 at this time, the reference exposure time period is 4 s. If the preset exposure compensation values of the images to be acquired in each frame are EV +1, the target exposure amount at the moment can be determined to be 800. Here, the exposure compensation of EV +1 means that the exposure amount corresponding to the photometric data of the imaging device is increased by one exposure step, that is, the actual exposure amount is twice the exposure amount corresponding to the photometric data.

In the embodiment of the present application, when the exposure compensation value is preset, the EV value corresponding to the determined reference exposure amount may be preset to 0, EV +1 refers to increasing one-stage exposure, that is, the exposure amount is 2 times of the reference exposure amount, EV +2 refers to increasing two-stage exposure, that is, the exposure amount is 4 times of the reference exposure amount, EV-1 refers to decreasing one-stage exposure, that is, the exposure amount is 0.5 times of the reference exposure amount, and so on.

For example, if the number of images to be captured is 7 frames, the corresponding preset exposure compensation value EV may be [ +1, +1, +1, +1,0, -3, -6 ]. The frame with the exposure compensation value EV +1 is preset, so that the noise problem can be solved, time domain noise reduction is carried out through the frame with higher brightness, and noise is suppressed while the details of a dark part are improved; presetting a frame with an exposure compensation value EV-6, solving the problem of high light overexposure and keeping the details of a high light area; the frames with preset exposure compensation values of EV0 and EV-3 can be used for maintaining the transition between highlight and dark areas and maintaining the good effect of bright-dark transition.

And 102, determining the exposure duration of each frame of image to be acquired according to the target exposure of each frame of image to be acquired and the preset sensitivity of each frame of image to be acquired.

In the embodiment of the application, as a possible implementation manner, when the preset sensitivity of each frame of image to be acquired is the same, the preset sensitivity of each frame of image to be acquired can be determined according to the ambient light brightness of a shooting scene. Under the condition that the light rays of a shooting scene are dark, the light sensitivity is improved, the shutter speed can be accelerated, and therefore the picture shake is reduced.

As another possible implementation manner, when the preset sensitivity of the image to be captured of each frame is the same, the preset sensitivity of the image to be captured of each frame may be determined according to the degree of shaking of the imaging device.

Specifically, in order to determine the degree of shaking, displacement information may be collected according to a displacement sensor provided in the imaging device, and then, the degree of shaking of the imaging device may be determined according to the collected displacement information of the imaging device. When the jitter degree of the imaging equipment is greater than or equal to a jitter threshold value, determining a preset light sensitivity value of each frame of image to be acquired in the current shooting scene as a first light sensitivity value; and when the shaking degree of the imaging equipment is smaller than the shaking threshold value, determining that the preset light sensitivity value of each frame of image to be acquired in the current shooting scene is a second light sensitivity value. The dithering threshold is a dithering value preset in the imaging equipment and used for determining a preset sensitivity value.

The first photosensitive value is greater than the second photosensitive value, the first photosensitive value is a preset multiple of the second photosensitive value, and the value of the preset multiple is greater than or equal to 2, because when the jitter degree is smaller, and when the graph to be acquired of each frame is acquired, lower sensitivity can be adopted, so that the exposure time is prolonged, the noise of the image to be acquired is reduced, and the imaging quality of the image is improved. As a possible implementation manner, in order to obtain lower noise, the second photosensitive value may be the minimum sensitivity of the imaging device, that is, the second photosensitive value has a value of 100ISO, and accordingly, the first photosensitive value may have a value in a range of 200, 400, or higher. Since the exposure amount is equal to the sensitivity multiplied by the exposure duration, in the embodiment of the present application, the exposure duration of each frame of image to be acquired can be determined according to the target exposure amount of each frame of image to be acquired and the preset sensitivity of each frame of image to be acquired.

As an example, if the target exposure of a frame of image to be captured determined by photometry is 800, and the preset sensitivity of the frame of image to be captured is 400ISO, the exposure time for capturing the frame of image is 2 s. By the method, the exposure time of the image to be acquired of each frame can be determined.

And 103, for at least one frame of image to be acquired, of which the exposure time length is greater than the upper limit of the time length, of the frames of image to be acquired, reducing the exposure time length and correspondingly increasing the sensitivity according to the upper limit of the time length.

The upper time limit refers to the maximum exposure time determined for obtaining better imaging quality according to the shooting scene. As a possible implementation manner, in the embodiment of the present application, the upper limit of the exposure time of each frame of the image to be acquired is related to the jitter degree of the imaging device.

Specifically, in order to determine the degree of shaking, displacement information may be collected according to a displacement sensor provided in the imaging device, and then, the degree of shaking of the imaging device may be determined according to the collected displacement information of the imaging device. When the jitter degree of the imaging equipment is greater than or equal to a jitter threshold value, determining the upper limit of the exposure time length of each frame of image to be acquired in the current shooting scene as a first time length; and when the shaking degree of the imaging equipment is smaller than the shaking threshold value, determining that the exposure time length upper limit of each frame of image to be acquired in the current shooting scene is a second time length. The dithering threshold is a dithering value preset in the imaging equipment and used for determining a preset sensitivity value.

In the embodiment of the present application, the first duration is smaller than the second duration because the first duration is determined when the jitter degree is large, in order to avoid image blur, the upper limit of the exposure duration, that is, the first duration, should be small, and conversely, when the jitter degree is small, the upper limit of the exposure duration may be set to be large.

As a possible implementation manner, the values of the first duration and the second duration are determined according to the ambient brightness, and the ambient brightness is inversely proportional to the value of the upper limit of the duration, that is, the higher the ambient brightness is, the smaller the value of the upper limit of the exposure duration is, for example, the first duration ranges from 150ms to 300ms, and the second duration ranges from 4.5s to 5.5 s.

In the embodiment of the application, when the exposure time of at least one frame of image to be acquired is greater than the upper limit of the exposure time, the exposure time of at least one frame of image to be acquired is reduced to the upper limit of the exposure time, the time ratio between the exposure time before the reduction of the at least one frame of image to be acquired and the upper limit of the exposure time is determined according to the relationship between the exposure amount, the sensitivity and the exposure time, and the sensitivity of the at least one frame of image to be acquired before the increase is multiplied by the time ratio to obtain the sensitivity of the at least one frame of image to be acquired after the increase.

In a scene, assuming that the upper limit range of the exposure time is 4.5s to 5s, taking the upper limit of the time 5s as an example in this embodiment, the image to be acquired is 7 frames, and according to the target exposure of each frame of image to be acquired and the preset sensitivity of each frame of image to be acquired, the exposure time corresponding to each frame of image to be acquired is determined to be 8s, 1.5s, 1ms, 180ms, and 280ms, so that the exposure time of the image to be acquired with the exposure time of 8s for 3 frames is greater than the upper limit of the exposure time, the exposure time of the image to be acquired with the exposure time of 8s for 3 frames is reduced to 5s, and the reduction of the exposure time to the upper limit of the time according to the upper limit of the time is realized.

And correspondingly increasing the sensitivity, taking the upper limit of the exposure time as 5s as an example, if the exposure time of the image to be acquired of a certain frame is greater than the upper limit of the exposure time, reducing the exposure time to the upper limit of the exposure time, and correspondingly increasing the sensitivity value. For example: the determined reference exposure time length and the reference exposure level are 2s and 100ISO, respectively, based on the luminance information of the current shot scene, i.e., the current exposure value is EV 0. When the exposure value of one frame of image to be collected is EV +2, the exposure time length and the sensitivity are respectively 8s and 100ISO, and since the exposure time length is greater than the upper limit of the time length by 5s when the exposure time length is 8s, the exposure time length of the EV +2 is set to 5s, and the ISO value is determined to be 8/5 x 100ISO, namely 160 ISO. Therefore, by updating the exposure time of the frame of image to be acquired, the exposure time can be reduced when the longest exposure time of a single frame is greater than the set maximum value of the exposure time, the sensitivity is increased through the corresponding proportion, and the image distortion caused by overexposure due to overlong exposure time is avoided while the exposure is ensured.

And 104, if the increased sensitivity is greater than the upper sensitivity limit, setting the sensitivity of the at least one frame of image to be acquired as the upper sensitivity limit.

In the embodiment of the application, the value of the sensitivity is a product obtained by multiplying a value of a sensor ISO by a value of a digital ISO, and similarly, the value of the upper limit of the sensitivity is a product obtained by multiplying an upper limit value of the sensor ISO by a value of the digital ISO, where the value of the sensor ISO is determined by hardware parameters of the imaging device, the upper limit value of the sensor ISO is a maximum ISO value that can be supported by the sensor, and the upper limit value of the digital ISO is determined based on experimental data. Because noise in an image is mainly introduced by a value of the digital ISO, the larger the value of the digital ISO, the more noise in the image, and therefore, in order to ensure imaging quality, the upper limit value of the digital ISO may not be set to be large, for example, a 1.5-fold gain value, that is, 150ISO, and the inventor finds through experiments that when the upper limit value of the digital ISO is 1.5-fold gain value, a large amount of noise is less generated in the imaged image, therefore, the upper limit value of the sensor ISO is multiplied by the upper limit value of the digital ISO to obtain a value of the sensitivity upper limit, so that the finally obtained imaged image does not contain massive cluster noise or a discontinuous phenomenon.

It should be noted that, in this embodiment, the upper limit value of the digital ISO is not limited, and a person skilled in the art may flexibly adjust the upper limit value of the digital ISO according to the situation of the night scene to be shot.

In the embodiment of the application, after the exposure time of a frame of image to be collected is reduced to the upper limit of the exposure time, the light sensitivity is correspondingly increased according to the determined time ratio, that is, the light sensitivity of the frame of image to be collected before being increased is multiplied by the time ratio to obtain the increased light sensitivity, wherein if the value of the light sensitivity of the frame before being increased is within the value range of the sensor ISO, the light sensitivity of the frame before being increased is determined by the value of the sensor ISO, and conversely, the light sensitivity of the frame before being increased is the product of the upper limit value of the sensor ISO and the value of the digital ISO, and further, after the light sensitivity is increased, whether the increased light sensitivity is greater than the upper limit value is determined according to the comparison between the increased light sensitivity and the upper limit value of the light sensitivity, if the increased light sensitivity is greater than the upper limit value of the light sensitivity, the value of the increased light sensitivity needs to be adjusted to be, the method and the device realize that the proper light sensitivity value is obtained within the range of the set digital ISO value, and avoid larger noise points in the image.

And 105, carrying out exposure control according to the exposure time and the sensitivity of each frame of image to be acquired.

In the embodiment of the application, the imaging device can perform exposure control according to the determined exposure time and sensitivity of each frame of image to be acquired to obtain each frame of image, and further synthesize and image multiple frames of images.

Further, as a possible implementation manner, the brightness of a multi-frame image to be acquired can be improved in a subsequent image processor ISP according to the gamma curve adjusted by the compensation value, so as to achieve the brightness of a preset composite image and meet the brightness requirement of a shot image, and a high-quality image with low noise can be obtained in a dark light shooting environment.

The exposure control method of the embodiment of the application determines the target exposure of each frame of image to be collected through photometry, determines the exposure time of each frame of image to be collected according to the target exposure of each frame of image to be collected and the preset sensitivity of each frame of image to be collected, reduces the exposure time and correspondingly increases the sensitivity for at least one frame of image to be collected with the exposure time being greater than the upper limit of the time in each frame of image to be collected, sets the sensitivity of at least one frame of image to be collected as the upper limit of the sensitivity if the increased sensitivity is greater than the upper limit of the sensitivity, and finally performs exposure control according to the exposure time and the sensitivity of each frame of image to be collected. Therefore, the exposure time of each frame of image to be acquired is determined through photometry, the light sensitivity is dynamically adjusted according to the adjustment of the exposure time, and then imaging is performed, so that the dynamic range of the image shot in the night scene shooting mode is improved, the noise in the shot image is effectively inhibited, the quality of the image shot in the night scene is improved, and the user experience is improved.

As a possible implementation manner, in the embodiment of the present application, before determining the target exposure amount of each frame of image to be acquired according to the reference exposure amount and the preset exposure compensation value of each frame of image to be acquired, first, the preset exposure compensation value of each frame of image to be acquired needs to be determined, referring to fig. 2, which may specifically include the following steps:

step 201, according to the picture content of the preview picture, determining that the current shooting scene belongs to a night scene

In the embodiment of the application, the preview picture of the current shooting scene can be acquired through the imaging device, and is used for determining whether the current shooting scene belongs to a night scene.

Specifically, because the environmental brightness values in different scenes are different, the contents of the preview image are also different, and whether the current shooting scene belongs to a night scene or not is judged according to the image contents of the current shooting scene preview image and the environmental brightness values of the areas.

For example, the picture content of the preview picture includes a night sky, a night scene light source, or the like, or the environmental brightness value in each region of the preview picture conforms to the brightness distribution characteristic of the image in the night scene environment, so that it can be determined that the current shooting scene belongs to the night scene.

Step 202, identifying a night scene mode applicable to the current shooting scene according to the shaking degree of the imaging device and/or whether the preview picture contains a human face.

In the embodiment of the application, displacement information of the imaging device in the shooting process can be acquired through the displacement sensor arranged on the imaging device, and then the current shaking degree of the imaging device is determined according to the acquired displacement information. Therefore, whether the user fixes the imaging device on the foot rest for shooting or shooting in a handheld mode can be judged through the shaking degree of the imaging device. And then, identifying a night scene mode applicable to the current shooting scene according to the current shaking degree of the imaging device. Wherein, the night scene mode adopts the foot rest mode or the hand-held mode.

As a possible implementation manner, the current shaking degree of the imaging device may be determined by acquiring current gyroscope (Gyro-sensor) information of the electronic device.

The gyroscope is also called an angular velocity sensor, and can measure the rotation angular velocity of the physical quantity during deflection and inclination. In the imaging device, the gyroscope can well measure the actions of rotation and deflection, so that the actual actions of a user can be accurately analyzed and judged. The gyroscope information (gyro information) of the electronic device may include motion information of the imaging device in three dimensional directions in a three-dimensional space, and the three dimensions of the three-dimensional space may be respectively expressed as three directions of an X axis, a Y axis, and a Z axis, where the X axis, the Y axis, and the Z axis are in a pairwise perpendicular relationship.

Therefore, in the embodiment of the application, the current shaking degree of the imaging device can be determined according to the current gyro information of the electronic device. The larger the absolute value of gyro motion of the electronic apparatus in three directions, the larger the degree of shake of the imaging apparatus. Specifically, absolute value thresholds of gyro motion in three directions may be preset, and the current shake degree of the imaging device may be determined according to a relationship between the sum of the acquired absolute values of gyro motion in the three directions and the preset threshold.

For example, it is assumed that the preset threshold values are a first threshold value a, a second threshold value B, and a third threshold value C, where a < B < C, and the sum of absolute values of gyro motion in three directions currently acquired is S. If S < A, determining the current jitter degree of the imaging equipment as 'no jitter'; if A < S < B, the current shaking degree of the imaging device can be determined to be 'slight shaking'; if B < S < C, it may be determined that the current degree of shake of the imaging device is "small shake"; if S > C, it can be determined that the current shake degree of the imaging apparatus is "large shake".

It should be noted that the above examples are only illustrative and should not be construed as limiting the present application. In actual use, the number of the threshold values and the specific numerical values of the threshold values can be preset according to actual needs, and the mapping relation between gyro information and the jitter degree of the imaging device can be preset according to the relation between gyro information and the threshold values.

As another possible implementation manner, a night scene mode applicable to the current shooting scene may be identified by determining that the preview picture of the imaging device contains enough human faces.

In the embodiment of the application, whether the preview picture contains a human face or not can be determined by a human face recognition technology. The face recognition technology is to analyze and compare face visual characteristic information to identify identity, belongs to the biological characteristic recognition technology, and is to distinguish organism individuals from the biological characteristics of organisms (generally specially people). Currently, face recognition technology has been applied in many fields, such as digital camera face auto-focus and smiling face shutter technology; enterprise, residential security and management; an access control system; camera surveillance systems, and the like. Commonly used face recognition algorithms include: a Recognition algorithm based on human face Feature points (Feature-based Recognition algorithms), a Recognition algorithm based on the whole human face image (application-based Recognition algorithms), a Recognition algorithm based on templates (Template-based Recognition algorithms), an algorithm for Recognition using a neural network (Recognition algorithms), and the like.

It should be noted that, when it is detected that the preview picture contains a human face, the photometry module of the imaging device may automatically perform photometry mainly based on the human face area, and determine the reference exposure amount according to the photometry result of the human face area. However, in a night scene, the illuminance of a face region is generally low, which results in a determined reference exposure amount, which is higher than the reference exposure amount determined when the face is not included, and if too many overexposed frames are still acquired when the face is included, the face region is easily overexposed, which results in a poor imaging effect of the acquired image. Therefore, for the same shake degree, the night scene mode adopted when the preview picture contains a human face is different from that when the preview picture does not contain a human face.

Step 203, determining the preset exposure compensation value of each frame of image to be acquired according to the night scene mode.

As a possible implementation manner, the shake degrees of the imaging devices are different, and the night scene modes suitable for the current shooting scene are also different, so that the preset exposure compensation values of the determined images to be acquired in each frame are also different. In the embodiment of the application, a mapping relationship between the shaking degree of the imaging device and the exposure compensation value can be preset, so that the preset exposure compensation value of the image to be acquired of each current frame is determined according to the shaking degree of the imaging device.

For example, when the shake degree of the imaging device is "no shake", the EV value range of the exposure compensation value corresponding to the image to be acquired for each frame may be preset to-6-2, and the difference between the adjacent EV values is 0.5; the shaking degree of the imaging device is 'slight shaking', the EV value range of the exposure compensation value corresponding to the image to be collected of each frame is preset to be-5-1, the difference value between the adjacent EV values is 1, and the like.

As another possible implementation manner, whether a preview picture of the imaging device contains a human face is detected, and when the preview picture contains the human face and does not contain the human face, the night scene modes suitable for the current shooting scene are different, so that the exposure compensation values preset for each frame of image to be acquired are different.

As another possible implementation manner, for the same shaking degree, different exposure compensation values may be used for determining each frame of image to be acquired according to whether the preview picture contains a human face. Therefore, for the same degree of shaking, a plurality of exposure compensation values may be corresponded. For example, the degree of shake of the imaging device is "slight shake", and the preset exposure compensation value of each frame of image to be acquired includes two cases, namely including a human face and not including a human face.

In the night view mode, when an image to be acquired includes a face, the illumination intensity of a face region is usually low, so that a determined reference exposure is caused, which is higher than the determined reference exposure when the face is not included, if too many overexposed frames are still acquired when the face is included, the face region is easily overexposed, so that the imaging effect of the acquired image is poor, and the corresponding exposure compensation mode needs to have a low exposure compensation range. Therefore, for the same shake degree, when the preview picture contains a human face, compared with the preview picture without the human face, after the current shake degree of the imaging device is determined and whether the preview picture contains the human face or not, the preset exposure compensation value which is consistent with the current actual situation can be determined.

According to the exposure control method, the preview picture is obtained, the current shooting scene is determined to belong to the night scene according to the picture content of the preview picture, the night scene mode applicable to the current shooting scene is identified according to the shaking degree of the imaging equipment and/or whether the preview picture contains the face, and then the exposure compensation value preset by each frame of image to be collected is determined according to the night scene mode. Therefore, according to the shaking degree of the imaging equipment and/or whether the preview picture contains the human face, the night scene mode in the shooting scene is determined, the preset exposure compensation value of each frame of image to be collected is further determined, the exposure duration of at least one frame of image to be collected is updated according to the duration upper limit, finally, exposure control is carried out according to the updated exposure duration and sensitivity of each frame of image to be collected, imaging is further carried out, the dynamic range of the image to be shot in the night scene shooting mode is improved, noise in the shot image is effectively inhibited, and the quality of the image to be shot in the night scene is improved.

In the above embodiments, it is described that the sensitivity increases when the exposure time is decreased, but the increased sensitivity cannot be greater than the upper limit of sensitivity, and when the increased sensitivity is adjusted downward according to the upper limit of sensitivity, the exposure time or sensitivity corresponding to other frames also needs to be adjusted correspondingly, so as to achieve the overall reduction of the exposure for shooting, so as to reduce noise in the image. Therefore, based on the foregoing embodiments, the present application further provides a possible implementation manner of an exposure control method, fig. 3 is a schematic flow chart of another exposure control method provided in the present application, and as shown in fig. 3, after step 104, the following steps may also be included:

step 305, determining a sensitivity ratio between the increased sensitivity of the at least one frame of image to be acquired and the upper limit of the sensitivity.

Specifically, if the increased sensitivity is greater than the upper sensitivity limit, the sensitivity of the at least one frame of image to be acquired after the increase in sensitivity is divided by the upper sensitivity limit to obtain a sensitivity ratio, which is used as a compensation value to adjust the exposure of each of the other frames of images to be acquired.

And step 306, updating the sensitivity or the exposure time of the images to be acquired of the other frames with the exposure time less than or equal to the upper limit of the time according to the sensitivity ratio.

Specifically, for the remaining frames of images to be acquired with the exposure time less than or equal to the lower limit of the time, the sensitivity or the exposure time before the updating of the remaining frames of images to be acquired is divided by the sensitivity ratio to obtain the updated sensitivity or the updated exposure time of the remaining frames of images to be acquired, because the exposure is determined by the sensitivity, the exposure time and the aperture, under the condition that the aperture is fixed in the embodiment, the exposure is the product of the sensitivity and the exposure time, and the reduced exposure is correspondingly obtained by dividing the sensitivity or the exposure time by the sensitivity ratio, so that when the ambient light is dark, after the sensitivity of the image to be acquired of the frame with the maximum exposure is reduced, the exposure of the images to be acquired of the other frames is correspondingly reduced, and after the subsequent frames of images to be acquired are synthesized, the noise points of the images are more continuous and the details are easier to align by integrally reducing the brightness, the imaging quality is improved.

In the exposure control method of the embodiment of the application, the target exposure of each frame of image to be acquired is determined through photometry, the dynamic range of the image to be shot in the night scene shooting mode is enlarged, the exposure time of each frame of image to be acquired is further determined, the exposure time of at least one frame of image to be acquired, which is longer than the upper limit of the exposure time, is reduced to the upper limit of the exposure time, the sensitivity is correspondingly increased, when the increased sensitivity of at least one frame of image to be acquired is larger than the upper limit of the sensitivity, the increased sensitivity is adjusted to the upper limit of the sensitivity again, the sensitivity ratio is determined, the exposure of other frames is correspondingly adjusted according to the sensitivity ratio, the noise in the shot image is effectively inhibited through the integral brightness adjustment, the noise points of the image are more continuous after the subsequent frames of image to be acquired are synthesized, the details are easier to align, and the imaging quality is improved.

In order to implement the above embodiments, the present application also provides an exposure control apparatus.

Fig. 4 is a schematic structural diagram of an exposure control apparatus according to an embodiment of the present disclosure.

As shown in fig. 4, the exposure control apparatus includes: a photometry module 41, a determination module 42, a first update module 43, a second update module 44, and a control module 45.

And the light metering module 41 is used for metering light to determine the target exposure of each frame of image to be acquired.

The determining module 42 is configured to determine an exposure duration of each frame of image to be acquired according to a target exposure of each frame of image to be acquired and a preset sensitivity of each frame of image to be acquired.

The first updating module 43 is configured to reduce the exposure duration and correspondingly increase the sensitivity of at least one to-be-acquired image, of which the exposure duration is greater than the upper limit of the duration, in each to-be-acquired image.

The second updating module 44 is configured to set the sensitivity of the at least one frame of image to be captured as the upper sensitivity limit if the increased sensitivity is greater than the upper sensitivity limit.

And the control module 45 is configured to perform exposure control according to the exposure duration and the sensitivity of each frame of the image to be acquired.

As another possible implementation manner, the exposure control apparatus further includes a third updating module and a first determining module.

The third updating module is used for determining the sensitivity ratio between the increased sensitivity of the at least one frame of image to be acquired and the upper limit of the sensitivity if the increased sensitivity is greater than the upper limit of the sensitivity; and updating the sensitivity or the exposure time of the images to be acquired of the other frames with the exposure time less than or equal to the upper limit of the time according to the sensitivity ratio.

As a possible implementation manner, the third updating module is specifically configured to:

and for the rest frames of images to be acquired with the exposure time length less than or equal to the lower limit of the time length, dividing the sensitivity or the exposure time length of the rest frames of images to be acquired before updating by the sensitivity ratio to obtain the updated sensitivity or the updated exposure time length of the rest frames of images to be acquired.

And the first determining module is used for determining the preset light sensitivity and the upper limit of the duration of each frame of image to be acquired according to the jitter degree.

As another possible implementation manner, the first determining module is specifically configured to:

acquiring collected displacement information from a sensor arranged on the imaging equipment;

determining the shaking degree of the imaging equipment according to the displacement information;

if the jitter degree is greater than or equal to the jitter threshold, determining that the preset light sensitivity value is a first light sensitivity value, and determining that the upper limit of the time length is the first time length;

if the jitter degree is smaller than the jitter threshold, determining that the preset light sensitivity value is a second light sensitivity value, and determining that the upper limit of the time length is the second time length; the first photosensitive value is greater than the second photosensitive value, and the first duration is less than the second duration.

The first photosensitive value is a preset multiple of the second photosensitive value, and the value of the preset multiple is more than or equal to 2; the second photosensitivity value is a minimum photosensitivity of the imaging apparatus.

Wherein the first time length value range is 150ms to 300 ms; the second duration ranges from 4.5s to 5.5 s.

As a possible implementation manner, the first updating module is specifically configured to:

reducing the exposure time of the at least one frame of image to be acquired to the upper limit of the time;

determining the time length ratio between the exposure time length before the reduction of the at least one frame of image to be acquired and the time length upper limit;

multiplying the sensitivity of the at least one frame of image to be acquired before the increase by the time length ratio to obtain the sensitivity of the at least one frame of image to be acquired after the increase.

As another possible implementation manner, the light metering module 41 may be further specifically configured to:

determining the reference exposure according to the brightness information of the preview image; the reference exposure amount includes a reference exposure time length and a reference sensitivity;

and determining the target exposure of each frame of image to be acquired according to the reference exposure and the preset exposure compensation value of each frame of image to be acquired.

As another possible implementation manner, the light metering module 41 further includes:

and the first determining unit is used for determining that the current shooting scene belongs to a night scene according to the picture content of the preview picture.

And the identification unit is used for identifying the night scene mode applicable to the current shooting scene according to the shaking degree of the imaging equipment and/or whether the preview picture contains the human face.

And the second determining unit is used for determining the preset exposure compensation value of each frame of image to be acquired according to the night scene mode.

It should be noted that the foregoing explanation of the embodiment of the exposure control method is also applicable to the exposure control apparatus of this embodiment, and is not repeated herein.

The exposure control device of the embodiment of the application determines the target exposure of each frame of image to be collected through photometry, improves the dynamic range of the image to be shot in a night scene shooting mode, further determines the exposure time of each frame of image to be collected, reduces the exposure time to the upper limit of the exposure time for at least one frame of image to be collected with the exposure time being greater than the upper limit of the exposure time, correspondingly increases the sensitivity, reduces the increased sensitivity to the upper limit of the exposure time when the increased sensitivity of at least one frame of image to be collected is greater than the upper limit of the sensitivity, determines the sensitivity ratio, correspondingly reduces the exposure of other frames according to the sensitivity ratio, effectively inhibits the noise in the shot image through integrally reducing the brightness, ensures that the noise points of the image are more continuous after the subsequent frames of image to be collected are synthesized, the details are easier to be aligned, and improves the imaging quality.

In order to implement the above embodiments, the present application also provides an electronic device, including: a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the exposure control method as described in the above embodiments when executing the program.

Referring to fig. 5, the present application further provides another electronic device 200. The electronic device 200 comprises a memory 50 and a processor 60. The memory 50 has stored therein computer readable instructions. The computer readable instructions, when executed by the memory 50, cause the processor 60 to perform the exposure control method of any of the above embodiments.

Fig. 5 is a schematic diagram of an internal structure of the electronic device 200 according to an embodiment. The electronic device 200 includes a processor 60, a memory 50 (e.g., a non-volatile storage medium), an internal memory 82, a display screen 83, and an input device 84 connected by a system bus 81. The memory 50 of the electronic device 200 stores, among other things, an operating system and computer-readable instructions. The computer readable instructions can be executed by the processor 60 to implement the exposure control method according to the embodiment of the present application. The processor 60is used to provide computing and control capabilities that support the operation of the overall electronic device 200. The internal memory 50 of the electronic device 200 provides an environment for the execution of computer readable instructions in the memory 52. The display 83 of the electronic device 200 may be a liquid crystal display or an electronic ink display, and the input device 84 may be a touch layer covered on the display 83, a button, a trackball or a touch pad arranged on a housing of the electronic device 200, or an external keyboard, a touch pad or a mouse. The electronic device 200 may be a mobile phone, a tablet computer, a notebook computer, a personal digital assistant, or a wearable device (e.g., a smart bracelet, a smart watch, a smart helmet, smart glasses), etc. It will be understood by those skilled in the art that the structure shown in fig. 5 is only a schematic diagram of a part of the structure related to the present application, and does not constitute a limitation to the electronic device 200 to which the present application is applied, and a specific electronic device 200 may include more or less components than those shown in the drawings, or combine some components, or have a different arrangement of components.

Referring to fig. 6, the electronic device 200 according to the embodiment of the present disclosure includes an Image Processing circuit 90, and the Image Processing circuit 90 may be implemented by hardware and/or software components, including various Processing units defining an ISP (Image Signal Processing) pipeline. FIG. 5 is a schematic diagram of image processing circuitry 90 in one embodiment. As shown in fig. 6, for convenience of explanation, only aspects of the image processing technology related to the embodiments of the present application are shown.

As shown in fig. 6, the image processing circuit 90 includes an ISP processor 91 (the ISP processor 91 may be the processor 60) and a control logic 92. The image data captured by the camera 93 is first processed by the ISP processor 91, and the ISP processor 91 analyzes the image data to capture image statistics that may be used to determine one or more control parameters of the camera 93. The camera 93 may include one or more lenses 932 and an image sensor 934. Image sensor 934 may include an array of color filters (e.g., Bayer filters), and image sensor 934 may acquire light intensity and wavelength information captured by each imaging pixel and provide a set of raw image data that may be processed by ISP processor 91. The sensor 94 (e.g., a gyroscope) may provide parameters of the acquired image processing (e.g., anti-shake parameters) to the ISP processor 91 based on the type of interface of the sensor 94. The sensor 94 interface may be a SMIA (Standard Mobile Imaging Architecture) interface, other serial or parallel camera interface, or a combination thereof.

In addition, the image sensor 934 may also send raw image data to the sensor 94, the sensor 94 may provide the raw image data to the ISP processor 91 based on the type of interface of the sensor 94, or the sensor 94 may store the raw image data in the image memory 95.

The ISP processor 91 processes the raw image data pixel by pixel in a variety of formats. For example, each image pixel may have a bit depth of 8, 10, 12, or 14 bits, and the ISP processor 91 may perform one or more image processing operations on the raw image data, gathering statistical information about the image data. Wherein the image processing operations may be performed with the same or different bit depth precision.

The ISP processor 91 may also receive image data from the image memory 95. For example, the sensor 94 interface sends raw image data to the image memory 95, and the raw image data in the image memory 95 is then provided to the ISP processor 91 for processing. The image Memory 95 may be the Memory 50, a portion of the Memory 50, a storage device, or a separate dedicated Memory within the electronic device, and may include a DMA (Direct Memory Access) feature.

Upon receiving raw image data from the image sensor 934 interface or from the sensor 94 interface or from the image memory 95, the ISP processor 91 may perform one or more image processing operations, such as temporal filtering. The processed image data may be sent to image memory 95 for additional processing before being displayed. The ISP processor 91 receives the processed data from the image memory 95 and performs image data processing on the processed data in the raw domain and in the RGB and YCbCr color spaces. The image data processed by ISP processor 91 may be output to display 97 (display 97 may include display screen 83) for viewing by a user and/or further processed by a Graphics Processing Unit (GPU). Further, the output of the ISP processor 91 may also be sent to an image memory 95, and the display 97 may read image data from the image memory 95. In one embodiment, image memory 95 may be configured to implement one or more frame buffers. Further, the output of the ISP processor 91 may be transmitted to an encoder/decoder 96 for encoding/decoding the image data. The encoded image data may be saved and decompressed before being displayed on the display 97 device. The encoder/decoder 96 may be implemented by a CPU or GPU or coprocessor.

The statistical data determined by the ISP processor 91 may be sent to the control logic 92 unit. For example, the statistical data may include image sensor 934 statistics such as auto-exposure, auto-white balance, auto-focus, flicker detection, black level compensation, lens 932 shading correction, and the like. The control logic 92 may include a processing element and/or microcontroller that executes one or more routines (e.g., firmware) that determine control parameters of the camera 93 and control parameters of the ISP processor 91 based on the received statistical data. For example, the control parameters of camera 93 may include sensor 94 control parameters (e.g., gain, integration time for exposure control, anti-shake parameters, etc.), camera flash control parameters, lens 932 control parameters (e.g., focal length for focusing or zooming), or a combination of these parameters. The ISP control parameters may include gain levels and color correction matrices for automatic white balance and color adjustment (e.g., during RGB processing), and lens 932 shading correction parameters.

The following steps are used for realizing the exposure control method by using the image processing technology in FIG. 6:

for at least one frame of image to be acquired, of which the exposure time length is greater than the upper limit of the time length, in each frame of image to be acquired, reducing the exposure time length according to the upper limit of the time length and correspondingly increasing the light sensitivity;

if the increased sensitivity is greater than the upper limit of the sensitivity, setting the sensitivity of at least one frame of image to be collected as the upper limit of the sensitivity;

In order to implement the above-mentioned embodiments, the present application also proposes a computer-readable storage medium having a computer program stored thereon, characterized in that the program, when executed by a processor, implements the exposure control method as described in the above-mentioned embodiments.

In the description herein, reference to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the application. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing steps of a custom logic function or process, and alternate implementations are included within the scope of the preferred embodiment of the present application in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present application.

The logic and/or steps represented in the flowcharts or otherwise described herein, e.g., an ordered listing of executable instructions that can be considered to implement logical functions, can be embodied in any computer-readable medium for use by or in connection with an instruction execution system, apparatus, or device, such as a computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. For the purposes of this description, a "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic device) having one or more wires, a portable computer diskette (magnetic device), a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). Additionally, the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory.

It should be understood that portions of the present application may be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, the various steps or methods may be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. If implemented in hardware, as in another embodiment, any one or combination of the following techniques, which are known in the art, may be used: a discrete logic circuit having a logic gate circuit for implementing a logic function on a data signal, an application specific integrated circuit having an appropriate combinational logic gate circuit, a Programmable Gate Array (PGA), a Field Programmable Gate Array (FPGA), or the like.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware related to instructions of a program, which may be stored in a computer readable storage medium, and when the program is executed, the program includes one or a combination of the steps of the method embodiments.

In addition, functional units in the embodiments of the present application may be integrated into one processing module, or each unit may exist alone physically, or two or more units are integrated into one module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. The integrated module, if implemented in the form of a software functional module and sold or used as a stand-alone product, may also be stored in a computer readable storage medium.

The storage medium mentioned above may be a read-only memory, a magnetic or optical disk, etc. Although embodiments of the present application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present application, and that variations, modifications, substitutions and alterations may be made to the above embodiments by those of ordinary skill in the art within the scope of the present application.

Claims

1. An exposure control method, characterized by comprising the steps of:

for at least one frame of image to be acquired, of which the exposure time length is greater than the upper limit of the time length, in each frame of image to be acquired, reducing the exposure time length according to the upper limit of the time length to obtain updated exposure time length and correspondingly increase the sensitivity;

if the increased sensitivity is greater than the upper sensitivity limit, setting the sensitivity of the at least one frame of image to be collected as the upper sensitivity limit to obtain updated sensitivity;

if the increased sensitivity is greater than the upper sensitivity limit, determining a sensitivity ratio between the increased sensitivity of the at least one frame of image to be acquired and the upper sensitivity limit;

for the rest frames of images to be acquired with the exposure time length less than or equal to the upper limit of the time length, updating the sensitivity or the exposure time length of the rest frames of images to be acquired according to the sensitivity ratio;

and carrying out exposure control according to the updated exposure time and sensitivity of each frame of image to be acquired.

2. The exposure control method according to claim 1, wherein updating the sensitivity or the exposure time of the remaining frames of the images to be captured, for which the exposure time is less than or equal to the lower limit of the time, according to the sensitivity ratio comprises:

3. The exposure control method according to claim 1, wherein, for at least one frame to be captured of the frames to be captured, in which the exposure duration is greater than the upper duration limit, decreasing the exposure duration according to the upper duration limit and correspondingly increasing the sensitivity, comprises:

4. The exposure control method according to any one of claims 1 to 3, wherein before determining the exposure time of each frame of the image to be captured according to the target exposure of each frame of the image to be captured and the preset sensitivity of each frame of the image to be captured, the method further comprises:

and determining the preset sensitivity of the image to be acquired of each frame and the upper limit of the duration according to the jitter degree.

5. The exposure control method according to claim 4, wherein the preset sensitivities for the images to be captured of the respective frames are the same, and the determining the preset sensitivities and the upper time limit according to the degree of shaking includes:

if the jitter degree is greater than or equal to a jitter threshold, determining that the preset sensitivity value is a first sensitivity value, and determining that the upper limit of the time length is a first time length;

if the jitter degree is smaller than a jitter threshold, determining that the preset sensitivity value is a second sensitivity value, and determining that the upper limit of the time length is a second time length; the first photosensitive value is greater than the second photosensitive value, and the first time length is less than the second time length.

6. The exposure control method according to claim 5,

the first photosensitive value is a preset multiple of the second photosensitive value, and the value of the preset multiple is more than or equal to 2;

the second photosensitivity value is a minimum photosensitivity of the imaging apparatus.

7. The exposure control method according to claim 5, wherein the values of the first period of time and the second period of time are determined according to ambient brightness;

the first time length value range is 150ms to 300 ms;

the second duration ranges from 4.5s to 5.5 s.

8. The exposure control method according to any one of claims 1 to 3, wherein the photometry to determine a target exposure amount for each frame of an image to be captured includes:

determining the reference exposure according to the brightness information of the preview image; the base exposure amount includes a base exposure time length and a base sensitivity;

9. The exposure control method according to claim 8, wherein before determining the target exposure amount of each frame of image to be captured according to the reference exposure amount and the preset exposure compensation value of each frame of image to be captured, the method further comprises:

determining that the current shooting scene belongs to a night scene according to the picture content of the preview picture;

identifying a night scene mode applicable to the current shooting scene according to the shaking degree of the imaging equipment and/or whether the preview picture contains a human face;

and determining the preset exposure compensation value of each frame of image to be acquired according to the night scene mode.

10. An exposure control apparatus, characterized in that the apparatus comprises:

the first updating module is used for reducing the exposure time length according to the upper time length limit of at least one frame of image to be acquired, of which the exposure time length is greater than the upper time length limit, in each frame of image to be acquired, so as to obtain the updated exposure time length and correspondingly increase the sensitivity;

the second updating module is used for setting the sensitivity of the at least one frame of image to be collected as the upper limit of the sensitivity to obtain the updated sensitivity if the increased sensitivity is greater than the upper limit of the sensitivity;

a third updating module, configured to determine a sensitivity ratio between the increased sensitivity of the at least one frame of image to be acquired and the upper sensitivity limit if the increased sensitivity is greater than the upper sensitivity limit, and update the sensitivity or the exposure duration of the remaining frames of images to be acquired according to the sensitivity ratio for the remaining frames of images to be acquired whose exposure duration is less than or equal to the upper sensitivity limit;

and the control module is used for carrying out exposure control according to the updated exposure duration and sensitivity of each frame of image to be acquired.

11. An electronic device, comprising: memory, processor and computer program stored on the memory and executable on the processor, which when executed by the processor implements the exposure control method according to any one of claims 1 to 9.

12. A computer-readable storage medium on which a computer program is stored, the program, when being executed by a processor, implementing the exposure control method according to any one of claims 1 to 9.