WO2018103197A1

WO2018103197A1 - Photograph-capture control method and terminal

Info

Publication number: WO2018103197A1
Application number: PCT/CN2017/073954
Authority: WO
Inventors: 黄晓峰
Original assignee: 深圳市金立通信设备有限公司
Priority date: 2016-12-08
Filing date: 2017-02-17
Publication date: 2018-06-14
Also published as: CN106791382A

Abstract

Provided is a photograph-capture control method, said method comprising: controlling a camera to defocus and continue to expose, sustaining said defocus for a first length of time (101); controlling the camera to focus and illuminating the flashlamp, sustaining said focus for a second length of time (102); turning off said flashlamp (103); ending exposure to obtain a target image (104). Also provided is a terminal. By means of the photograph-capture control method and terminal, it is possible to obtain a blurred background image in a dark environment.

Description

Photograph control method and terminal

The present application claims priority to Chinese Patent Application No. 2016-1111948, the entire disclosure of which is incorporated herein by reference.

Technical field

The present invention relates to the field of image processing, and in particular, to a photographing control method and a terminal.

Background technique

With the rapid development of information technology, terminals (such as mobile phones, tablets, etc.) are used more and more frequently. With the pursuit of quality of life, the requirements for the terminal are getting higher and higher, which not only requires the processing speed of the terminal to be faster, but also puts higher requirements on the camera function of the terminal. At present, although the dual camera can achieve the background blur effect, in the process of background blur, the map algorithm and the depth extraction algorithm are usually used, but in the dark environment, the map algorithm and the depth extraction algorithm are used. The accuracy is poor and the robustness is poor, resulting in poor background blurring.

Summary of the invention

The embodiment of the invention provides a camera control method and a terminal, which can improve the background blur effect of the image in a dark environment.

A first aspect of the embodiments of the present invention provides a photographing control method, including:

Controlling the camera to be out of focus and continuously exposing, wherein the defocusing continues for a first length of time;

Controlling the camera to focus, lighting the flash, wherein the focus continues for a second length of time;

Turning off the flash;

End the exposure and get the target image.

A second aspect of the embodiments of the present invention provides a terminal, including:

a first control unit, configured to control the camera to be out of focus, and to continue exposure, wherein the defocusing continues for a first length of time;

a second control unit, configured to control the camera to focus, and illuminate the flash, wherein the focus continues for a second length of time;

a closing unit for turning off the flash;

A processing unit for ending the exposure to obtain a target image.

A third aspect of the embodiments of the present invention provides a terminal, including:

a memory storing executable program code;

a processor coupled to the memory;

The processor invokes the executable program code stored in the memory to perform some or all of the steps of the photographing control method as described in the first aspect.

Embodiments of the present invention have the following beneficial effects:

The camera can be controlled to defocus and continuously expose, wherein the defocusing continues for a first time length, the camera is controlled to focus, and the flash is illuminated, wherein the focus is continued for a second time length, the flash is turned off, and the exposure is ended. , get the target image. Thereby, a background blur image with better effect can be obtained in a dark environment.

DRAWINGS

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly described below. It is obvious that the drawings in the following description are some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

1 is a schematic flow chart of a first embodiment of a photographing control method according to an embodiment of the present invention;

FIG. 2 is a schematic flowchart diagram of a second embodiment of a photographing control method according to an embodiment of the present invention; FIG.

2a is a timing diagram of a rear curtain synchronization mode according to an embodiment of the present invention;

2b is a timing diagram of a front curtain synchronization mode according to an embodiment of the present invention;

2c is a timing diagram of an intermediate synchronization mode according to an embodiment of the present invention;

2d is a timing diagram of a stroboscopic mode provided by an embodiment of the present invention;

FIG. 3 is a schematic flowchart diagram of a third embodiment of a photographing control method according to an embodiment of the present invention; FIG.

4a is a schematic structural diagram of a first embodiment of a terminal according to an embodiment of the present invention;

FIG. 4b is still another schematic structural diagram of the terminal depicted in FIG. 4a according to an embodiment of the present invention; FIG.

FIG. 4c is still another schematic structural diagram of the terminal depicted in FIG. 4a according to an embodiment of the present disclosure;

FIG. 4d is still another schematic structural diagram of the terminal depicted in FIG. 4a according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of a second embodiment of a terminal according to an embodiment of the present invention.

detailed description

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

The terminal described in the embodiment of the present invention may include a smart phone (such as an Android mobile phone, an iOS mobile phone, a Windows Phone mobile phone, etc.), a tablet computer, a palmtop computer, a notebook computer, a mobile Internet device (MID, Mobile Internet Devices), or a wearable device. The above terminals are merely examples, not exhaustive, and include but are not limited to the above terminals.

It should be noted that the terminal may be provided with a camera, the camera may include at least a lens and an image sensor, and the lens may be used for focusing, defocusing, exposing, etc., the image sensor includes a plurality of photosensitive units, and each photosensitive unit corresponds to one pixel. When the terminal controls the camera to start exposure, the photosensitive unit of the image sensor starts to expose. Generally, the photosensitive unit of the image sensor is not exposed at the same time, but each exposure unit starts to have different exposure time and end exposure time. There may be some photosensitive cells that have finished exposing, and some of the photosensitive cells may still be exposed.

Optionally, in the embodiment of the present invention, the focus and defocus control of the camera are described below, and can be controlled by using a lens focus motor of the camera. The focus motor generally has an ultrasonic motor, a stepping motor and a voice coil (Voice Coil Motor). , VCM) motor. For example, for a mobile phone, the camera module of the mobile phone can use a VCM motor. Generally, the VCM motor controls the entire movement of the lens to take about 10-30 milliseconds. Of course, you can also use a stepper motor or an ultrasonic motor to push the lens of the camera. Different focus can be achieved during the movement of the lens. The degree of defocus of the above control lens defocusing determines the degree of background blur. If the user wants a large background blur, the lens can be controlled to the maximum degree of out of focus. For example, the current portrait is at 1.5 meters, and the lens can be controlled. Moving to the end of the near end, in general, the lens motor's stroke covers the macro and infinity, leaving a certain margin. In order to achieve the purpose of increasing the degree of blurring without ensuring damage to the lens, the lens motor can be controlled to move to the mechanical end of the telephoto end, or to the mechanical end of the near focal length. Which is specific? One end can be determined according to the actual situation. In the embodiment of the present invention, the handheld terminal can be implemented. Of course, the tripod can be used to implement the terminal. If the tripod is used to fix the terminal, a similar or even better effect can be obtained. The main reason is that the tripod can be avoided due to the process of the handheld terminal. Image motion blur caused by hand shake (also known as hand shake blur).

It should be noted that, in the embodiment of the present invention, there are three typical synchronization modes in a sequential synchronization manner of a typical complementary metal oxide semiconductor (CMOS) image sensor, a flash, and a lens focus state. They are called rear curtain sync mode, front curtain sync mode and intermediate sync mode. The flash must be lit during the period in which each line of pixels is in the exposure state. Otherwise, the flash energy obtained by each line of pixels is not the same, then the brightness of the pixels of different lines may be different. The main difference between rear curtain synchronization, front curtain synchronization, and intermediate synchronization is that the motion smear of the near body is distributed on which side of the clear body. The smear of the rear curtain synchronization is distributed in the opposite direction of the moving direction of the moving body, and the front curtain synchronization is reversed. There are smear on both sides of the middle synchronous motion direction. Which synchronization method needs to be selected depends on the user's preference, different users like different smear effects, and some users do not care about this smear. Spreading the smear on either side of the clear body helps to weaken the smear effect and make the image look clearer. The exposure time of the first line and the bottom line of the rolling shutter CMOS image sensor is sequential and not synchronized, and the image sensor of the global shutter is all exposed at the same time.

In the following, only the synchronous mode of the rolling shutter is listed. Of course, the global shutter realizes the synchronization mode more simply, because there is no line exposure unsynchronization problem, and the photographing control method in the embodiment of the present invention can also be used.

FIG. 1 is a schematic flowchart diagram of a first embodiment of a photographing control method according to an embodiment of the present invention. The photographing control method described in this embodiment includes the following steps:

101. Control the camera to be out of focus and continue to expose, wherein the defocusing continues for a first length of time.

Wherein, the terminal can control the camera to defocus, and the image captured by the camera will become blurred after the defocusing, so that the user can feel the background blur effect, wherein the defocus can last for the first time length, the first time The length can be set by the system default or by the user. Among them, the exposure can also correspond to an exposure time. The exposure duration is at least greater than or equal to the length of time between the exposure of the bottommost row of pixels of the image sensor of the image sensor and the end exposure of the first row of pixels.

Alternatively, the exposure may be performed simultaneously while controlling the camera to be out of focus. For example, one thread can be used to control the camera out of focus, another thread is used to control the exposure, and two threads are synchronized. As another example, one process can be used to control the camera out of focus, another process is used to control the exposure, and the two processes are synchronized. In this way, control camera defocusing and exposure synchronization can be realized, and the advantage of synchronization is that at the beginning of defocusing, the photosensitive unit of the image sensor can be exposed to the exposure, so that in step 101, as much as possible The photosensitive unit is exposed.

Optionally, after the camera is out of focus, the first preset time period is separated, and then the exposure is continued. Of course, the first preset time period is as short as possible, wherein the first preset time period may be 0.01 seconds and 0.0095 seconds. , 0.0085 seconds, 0.0092 seconds, and so on.

102. Control the camera to focus, and illuminate the flash, wherein the focus continues for a second time length.

Wherein, after the end of the first time length, the camera can be controlled to focus and the flash is illuminated, wherein the flash is continuously lit, and optionally, the brightness of the flash can remain unchanged during the continuous lighting process, of course, It may also be in a change, and the length of the focus duration is the second length of time.

Alternatively, the flash can be illuminated simultaneously while controlling the focus of the camera. For example, one thread can be used to control the camera to focus, and another thread can be used to illuminate the flash, and the two threads are synchronized. As another example, one process can be used to control the focus of the camera, and another process can be used to illuminate the flash, and the two processes are synchronized. In this way, it is possible to control the camera to focus and illuminate the flash simultaneously, and the advantage of the synchronization is that the surrounding environment is brightened at the beginning of the focusing, and thus the focusing can be achieved more quickly.

Optionally, after the camera is controlled to focus, the second preset time period is separated, and then the flash is turned on. Of course, the second preset time period is as short as possible, wherein the second preset time period may be 0.01 seconds and 0.0095. Seconds, 0.0085 seconds, 0.0092 seconds, and so on.

It should be noted that in a dark environment, when the flash is not used, if the exposure time is short, there is more noise in the image. If the flash is used, motion blur is likely to occur in the image.

103. Turn off the flash.

Among them, it can be detected whether the second time length is over, and if so, the flash is turned off.

Alternatively, when the flash is turned off, some of the photosensitive cells in the image sensor have not ended the exposure.

104. End exposure to obtain a target image.

After the end of the exposure, the image data collected by each photosensitive unit in the image sensor, and the image data is processed by a series of image algorithms to obtain a target image, wherein the image algorithm processing can refer to the prior art, that is, Usually, the terminal performs a series of processing on the original image data collected by the image sensor to obtain a final image. The exposure time may be greater than the first time length, and the exposure time may be greater than the second time length. Of course, the exposure time may also be greater than the sum of the first time length and the second time length.

Optionally, the foregoing

steps

101 and 102 may include the following steps:

It is detected whether all the photosensitive cells of the image sensor have started exposure, and if so, step 102 is performed.

Wherein, when all the photosensitive cells of the image sensor have started to expose, the accuracy of the focusing in step 102 can be improved, and the focusing speed can be accelerated. Specifically, it is possible to detect whether all the photosensitive cells of the image sensor have all started exposure by the frame synchronization signal. For the image sensor of the rolling shutter, a delay time can be preset to detect whether the bottom line pixel starts to be exposed. If it starts, it can be determined that all the photosensitive units have started according to the characteristics of the image sensor of the rolling shutter. exposure. For an image sensor with a global shutter, all pixels in the sensor begin to be exposed after the frame sync signal arrives. Therefore, it can be detected based on the control signal whether or not all the photosensitive cells have started exposure.

Optionally, the foregoing

steps

101 and 102 may include the following steps:

Detecting whether at least one photosensitive unit is present in all of the photosensitive cells of the image sensor ends the exposure, and if so, executing step 102.

Wherein, when all the pixels are exposed, the process of step 102 can be performed, focus is achieved, the flash is turned on, used to enhance the brightness of the dark environment, the exposure speed can be accelerated, and the focusing speed and accuracy can be improved. For the image sensor of the rolling shutter, there are two cases where only a part of the photosensitive unit is being exposed, other pixels have stopped exposing, or have not started to be exposed, for example: 1. The first line of pixels has begun to be exposed, the bottom is The row pixels have not yet begun to be exposed; 2. The first row of pixels has ended exposure and the bottom row of pixels is being exposed. In both cases, the focus and the flash can be off.

Optionally, it is worth noting that the exposure duration and the flash illumination duration can be set by the system default or by the user. The longer the exposure time under the same conditions, the higher the background brightness, the lower the sensitivity ISO and the longer the exposure time, and the better the signal-to-noise ratio can be obtained with the same background brightness. In the case of the same ISO, the longer the flash is lit, the brighter the image, but the blurring may be exacerbated. Generally speaking, the bigger the brightness of the flash, the better. If you want to reduce the brightness of the image, you can pass This is achieved by shortening the length of time the flash is lit. Taking a Light-Emitting Diode (LED) flash as an example, the switching time of an LED flash is usually on the order of microseconds, allowing precise control of time. Considering the problem of heat generation, the LED flash should not be lit for more than 0.1 second at full load, and the cooling time for two full-load lighting is recommended to be no less than 3 seconds to avoid damage to the LED flash. The terminal can default sensor parameters (such as: exposure duration, flash duration, color, etc.), of course, the user's preferences can be mapped to the sensor data, and then, in actual use, the relevant sensor is used and called The mapping relationship may be divided into multiple levels according to the ambient brightness, and each level corresponds to a set of sensor data, and a correspondence relationship between the ambient brightness and the sensor data is established. Then, as long as the current ambient brightness is known, it can be known which A set of sensor parameters.

Optionally, after the flash is turned off in the above step 103, and after the exposing of the step 104, the target image is obtained, and the following steps may be further included:

Perform the following procedure N times, where N is a positive integer:

Controlling the camera to be out of focus, wherein the defocusing continues for a third length of time;

Controlling the camera to focus, lighting the flash, wherein the focus continues for a fourth time length;

Turn off the flash.

The third time length may be the same as or different from the first time length, and the fourth time length may be the same as or different from the second time length, and the third time length and the fourth time length may be defaulted by the system or the user. Set it yourself.

Further, if the flash is fired multiple times in the exposure interval, and the lens is also ensured to be in focus during the flashing of the flash, it is out of focus in other time slots (ie, the above process is N times). In a few flash times, if there is a certain offset in the subject, it is possible to achieve the effect that the same subject appears multiple times in the same screen. And the background is blurred.

In the embodiment of the invention, the flash and the lens focusing device can be synchronously controlled during the image sensor exposure process, and the background blurring effect under low illumination is realized, which has the advantages of natural blur effect, less image noise, clear image subject, and the like. Compared with the scheme of the camera and the virtual blur, the scheme is highly reliable, and the embodiment of the invention can have high reliability under low illumination. In addition, the embodiment of the present invention does not require any image fusion technology, and an optical background blurred image can be output by single frame imaging.

In the process of implementing the embodiments of the present invention, in order to reduce the noise of the image and reduce the motion blur of the subject, a control lighting flash is employed.

The following describes the different situations in the same environment and the same scenario as follows:

In the first case, if the photographing control method in the embodiment of the present invention is adopted, the exposure time is set to 0.1 second, the flash is illuminated for 30 milliseconds, and the movement time of the lens VCM motor from defocus to focus is synchronously controlled by about 20 milliseconds. The flash is only illuminated when the focus is achieved, and the target image is obtained. Among them, due to the short exposure time, the background may be dark in a dark environment, but it has a background blur effect.

In the second case, the exposure time is increased to 2 seconds, the flash is illuminated for 30 milliseconds, and the movement time of the lens VCM motor from defocus to focus is synchronously controlled for about 20 milliseconds, and the flash is illuminated when the focus is achieved. The background is out of focus for most of the time period, so the background is defocused in the final image, and the foreground is illuminated for 30 milliseconds under the flash light. The energy corresponding to the motion smear is much less than the energy of the flash. Therefore, the foreground Clear, the background also has a defocused effect.

It can be seen from the above that in the process of executing the embodiment of the present invention, there are certain requirements on the exposure time and the duration of the flash, the exposure time is short, and the background is dark. The duration of the flash is used to enhance close-up subjects, such as brightening portraits, and thus can further assist in achieving focus and help increase the energy of the pixels corresponding to the photosensitive cells in the image sensor.

The camera can be controlled to defocus and continuously expose, wherein the defocusing continues for a first time length, after the first time length, the camera is controlled to focus, and the flash is illuminated, wherein the focus continues for the second time. The length of time, after the second length of time, turn off the flash and end the exposure to get the target image. Thereby, a background blur image with better effect can be obtained in a dark environment.

With reference to FIG. 2, it is a schematic flowchart of a second embodiment of a photographing control method according to an embodiment of the present invention. The photographing control method described in this embodiment includes the following steps:

201. Control the camera to be out of focus and continue to expose, wherein the defocusing continues for a first length of time.

202. Control the camera to focus, and illuminate the flash, wherein the focus continues for a second time length.

203. Turn off the flash.

Optionally, illuminating the flash can be implemented as follows:

Light up the flash multiple times, for example, light-off-light-off-off, so that you can get the picture in Figure 2d Describe the effect.

204. Control the camera to continue to defocus for a third time length.

205. After the third time length, the exposure is ended to obtain a target image.

The following describes the embodiments of the present invention in combination with the above three synchronization modes (the rear curtain synchronization mode, the front curtain synchronization mode, and the intermediate synchronization mode):

2a, a timing diagram of an embodiment of the present invention is implemented in a rear-curtain synchronization mode. For the timing of exposure, the horizontal axis t represents time, the vertical axis represents row coding, and for the timing of the flash state, the horizontal axis t represents time, and the vertical axis represents High and low level, low level does not light, high level lights; for the timing of the lens, the horizontal axis t represents time, the vertical axis represents defocus or focus, and the shaded area can represent rolling shutter CMOS All lines of the image sensor are in the exposed area. Of course, for an image sensor of the global shutter, this shaded area also exists, and there is no unsynchronized area. Embodiments of the present invention can be implemented by simply illuminating the flash in a time zone that is about to end in this shaded area and controlling the lens to focus. As can be seen from Figure 2a, the flash and focus are illuminated during the time period within the shaded area.

2b, the timing diagram of the embodiment of the present invention is implemented in the front curtain synchronization mode. For the timing of exposure, the horizontal axis t represents time, the vertical axis represents row coding, and for the timing of the flash state, the horizontal axis t represents time, and the vertical axis represents High and low level, low level does not light, high level lights; for the timing of the lens, the horizontal axis t represents time, the vertical axis represents out-of-focus or focus, and the shaded area can represent all lines of the rolling shutter CMOS image sensor Both are in the exposed area. Embodiments of the present invention can be implemented by simply illuminating the flash in a time zone beginning with this shaded area and controlling the lens to focus. It can be seen from Fig. 2b that the flash is illuminated during the time period in the shaded area, and the focus is first focused and then defocused.

2c, the timing diagram of the embodiment of the present invention is implemented in the intermediate synchronization mode. For the timing of the exposure, the horizontal axis t represents time, the vertical axis represents row coding, and for the timing of the flash state, the horizontal axis t represents time and the vertical axis represents high and low. Level, low level does not light, high level lights; for the timing of the lens, the horizontal axis t represents time, the vertical axis represents defocus or focus, and the shaded area can represent all the lines of the rolling shutter CMOS image sensor In the exposed area. Embodiments of the present invention can be implemented by simply illuminating the flash in a certain time zone intermediate the shaded area and controlling the lens to focus. If you select the area in the middle and the moving target moves at a constant speed, the motion smear in the image may just be evenly distributed on both sides of the clear target. It can be seen from Fig. 2c that the flash is illuminated during the time period in the shaded area, and the focus is first focused and then defocused.

Optionally, as shown in FIG. 2d, FIG. 2d is a timing diagram of an embodiment of the present invention in a stroboscopic mode. For the timing of exposure, the horizontal axis t represents time, the vertical axis represents row coding, and the timing of the flash state, horizontal axis t Indicates the time, the vertical axis indicates high and low level, the low level does not light, and the high level lights; for the timing of the lens, the horizontal axis t represents time, the vertical axis represents defocus or focus, and the flash is repeated multiple times during the exposure time. And also ensure that the lens is in focus during the flashing process, and is out of focus in other time slots. In a few flash times, if there is a certain offset in the subject, it is possible to achieve the effect that the same subject appears multiple times in the same screen. And the background is blurred. It can be seen from Fig. 2d that the flash is illuminated twice in the time zone within the shaded area, and the effect that the same subject is appearing multiple times in the same picture can be obtained.

The camera can be controlled to defocus and continuously expose, wherein the defocusing continues for a first time length, after the first time length, the camera is controlled to focus, and the flash is illuminated, wherein the focus continues for the second time. The length of time, after the second time length, turns off the flash, and controls the camera to defocus for a third time length. After the third time length ends, the exposure ends, and the target image is obtained. Thereby, a background blur image with better effect can be obtained in a dark environment, and the blurring effect is more remarkable due to two defocuss.

With reference to FIG. 3, it is a schematic flowchart of a third embodiment of a photographing control method according to an embodiment of the present invention. The photographing control method described in this embodiment includes the following steps:

301. Control the camera to perform focusing to obtain a focus position.

Optionally, when the terminal controls the camera to focus, the focus position can be selected in the preview image by human-computer interaction.

Optionally, when the terminal controls the camera to focus, the preview image may be face-recognized, and the detected face position is used as a focus position.

302. Determine an exposure duration and a second length of time.

Alternatively, the exposure duration can be determined by photometric techniques. Among them, the main principle of the metering technology is as follows: assuming that the reflectance of the measured light area is 18%, the metering is performed by this ratio and then the aperture and shutter values are determined. The aperture and the shutter are related, in the same illumination. Under the condition, the larger the aperture value, the smaller the shutter value, that is, the shorter the exposure time, and if the aperture value is smaller, the shutter value is larger, that is, the exposure time is longer. 18% of this value is based on the reflection of the midtones (gray tone) in the natural scene. If the white color of the viewfinder is mostly, the reflected light will exceed 18%, if it is all white The scene can reflect about 90% of the incident light, and if it is a black scene, the reflectivity is only a few percent. Further, the second time length may also be determined according to the photometric technique. Generally, the shorter the exposure time, the shorter the second time length and the longer the exposure time, the longer the second time length.

Further, in the prior art, the terminal may include different metering modes, and the metering range and adaptability are also different for different metering modes. Applicable to almost all shooting scenes, the “Evaluation Metering” mode, which is set by default, is centered on the AF point used for autofocus, focusing on the focus of the subject while taking into account the overall balance of the screen for metering. The metering value is calculated using an advanced algorithm and converted to the exposure duration. The narrowest metering range is the “spot metering” mode, which only responds to the central portion of the brightness. Generally, the evaluation metering mode is sufficient. Spot metering can be used when you want to quickly get a proper exposure for a specific subject in a specific scene such as backlighting. If it is a general landscape photography, it is convenient to select the evaluation metering mode. However, if the scene is complex and interlaced, it is better to use the spot metering mode.

Optionally, the exposure duration can also be determined according to the ambient brightness. The brighter the ambient brightness, the shorter the exposure duration, and the darker the ambient brightness, the shorter the exposure duration. The ambient brightness may be obtained by an ambient light sensor, or may be obtained by performing a photometric estimation by a preview image of the image sensor under the condition of no flash, that is, calculating an average brightness of the preview image as the current ambient brightness.

Optionally, the second time length may be determined by the terminal according to the distance information calculation and the preset rule to determine the flash lighting duration. After the distance information is determined, the lighting duration of the flash corresponding to the current distance, that is, the second time length, may be determined according to the mapping relationship between the distance information and the lighting duration of the flash.

The following is how the distance information is determined:

1. Detecting a target object selected by a user from a preview image acquired by the camera, and focusing the target object.

In a specific embodiment, the ranging function can be set in advance. Before measuring the object distance, that is, the distance between the target object and the camera, the distance measurement function is turned on, the camera is aimed at the object to be tested, that is, the target object, and the target object is obtained by detecting the current user operation instruction, thereby triggering the pair. The target object performs focusing, for example, when detecting that the user clicks on an object on the display screen as the target object, and triggers focusing on the target object.

2. Adjusting the position of the motor built in the camera to obtain the contrast corresponding to the target object when the motor is in different positions.

3. Determine a maximum contrast value from the contrast, and obtain an image distance corresponding to the maximum contrast value, where the image distance is a distance between a lens of the camera and the sensor.

It should be noted that the contrast of the image acquired by the camera is associated with the motor position. Specifically, the mapping relationship between the contrast and the motor position can be preset, and the contrast of the image corresponding to the different motor positions can be obtained by adjusting the position of the built-in motor of the camera. When the motor is adjusted to the maximum image contrast, that is, the image is the clearest, that is, The image distance corresponding to the target object may be determined according to the motor position corresponding to the maximum contrast value.

Specifically, the motor can be restored to the initial position, and then the motor is sequentially moved to the left by one step (here, the initial position is assumed to be at the rightmost position), and the contrast of the preview image obtained by each moving motor is respectively obtained, and the contrast is obtained from the contrast. The maximum contrast value is determined, and the number of motor steps corresponding to the maximum contrast value is obtained, so that the image distance corresponding to the target object is calculated according to the initial position of the motor and the number of steps of the motor.

4. Calculate an object distance between the target object and the lens according to the image distance.

In a specific embodiment, a difference between the image distance and the focal length of the lens may be obtained by acquiring a product of the image distance and a lens focal length set in advance, and the quotient of the product and the difference is used as the The object distance between the target object and the lens.

Optionally, the second length of time may also be determined by a distance between the subject and the terminal, wherein depth information corresponding to the preview image may be acquired, and a distance between the subject and the terminal is determined according to the depth information, and the distance is further Then, the second time length is longer, and the shorter the distance, the shorter the second time length.

303. Control the camera to be out of focus, and continue exposure according to the exposure duration, wherein the defocus is continued for a first time length.

304. Focusing according to the focus position to illuminate the flash, wherein the focus continues for a second time length.

305. Turn off the flash.

306. End exposure to obtain a target image.

Optionally, before the foregoing step 303, the following steps may be further included:

The color of the flash is determined based on the color information of the current ambient light.

For example, step 302 can also determine color information of a flash or the like. Optionally, flash color information can be determined according to ambient light color information, as follows:

Starting a camera; acquiring color data of the light source from the photographing auxiliary device, the color data is collected by a color sensor disposed on the photographing auxiliary device, the collection angle of the color sensor is determined by the user; and adjusting the color of the fill light source according to the color data ; Start the fill light source after adjusting the color; capture the image through the camera.

Optionally, a mapping relationship between the color information of the ambient light and the color of the flash is set in advance, and then the color of the flash may be determined according to the mapping relationship. In this way, the color of the flash is matched with the environment, and the photographing effect is better.

The embodiment of the present invention can first determine the focus position, the second time length, the exposure time, control the camera defocus, and continue exposure with the exposure duration, wherein the defocus continues for the first time length, and the camera is controlled to The focus position is focused to illuminate the flash, wherein the focus continues for the second length of time, the flash is turned off, the camera is again controlled for a third time length of focus, and the exposure is ended to obtain a target image. Thereby, a background blur image with better effect can be obtained in a dark environment, and the blurring effect is more remarkable due to two defocuss.

In the following, in the following, the device for implementing the photographing control method provided by the embodiment of the present invention is as follows:

FIG. 4 is a schematic structural diagram of a first embodiment of a terminal according to an embodiment of the present invention. The terminal described in this embodiment includes: a first control unit 401, a second control unit 402, a shutdown unit 403, and a processing unit 404, as follows:

a first control unit 401, configured to control the camera to be out of focus, and to continue exposure, wherein the defocusing continues for a first length of time;

a second control unit 402, configured to control the camera to focus, illuminate the flash, wherein the focus continues for a second time length;

a closing unit 403, configured to turn off the flash;

The processing unit 404 is configured to end the exposure to obtain a target image.

Optionally, as shown in FIG. 4b, FIG. 4b is a modified structure of the terminal described in FIG. 4a, and FIG. 4b may further include: a third control unit 405, as follows:

The third control unit 405 is configured to control the camera to continue to defocus for a third time length after the closing unit 403 turns off the flash, and the processing unit 404 ends the exposure to obtain the mesh. Target image.

Optionally, as shown in FIG. 4c, FIG. 4c is a modified structure of the terminal described in FIG. 4a, and FIG. 4c further includes: a first detecting unit 406, as follows:

a first detecting unit 406, configured to: after the first control unit 401 controls the camera to be out of focus, and continuously exposes, detecting that all the photosensitive cells of the image sensor are in an exposed state, if the detection result of the first detecting unit 406 is Yes, the camera controls the focus by the second control unit 402 to illuminate the flash.

Optionally, as shown in FIG. 4d, FIG. 4d is a modified structure of the terminal described in FIG. 4a, and FIG. 4d may further include: a fourth control unit 407 and a determining unit 408, as follows:

The fourth control unit 407 is configured to control the camera to perform pre-focusing to obtain a focus position before the first control unit 401 controls the camera to defocus and continuously expose the exposure;

The determining unit 408 is configured to determine an exposure duration of the exposure and the second length of time.

Optionally, after the closing unit 403 turns off the flash, and the processing unit 404 ends the exposure to obtain the target image, the first control unit 401, the second control unit 402, and the shutdown unit 403 is configured to perform the following process N times, where N is a positive integer:

The first control unit 401 controls the camera to be out of focus, wherein the defocusing continues for a third time length;

The second control unit 402 controls the camera to focus, and illuminates the flash, wherein the focus continues for a fourth time length;

The closing unit 403 turns off the flash.

The terminal described in the embodiment of the present invention can control the camera to defocus and continuously expose, wherein the defocusing continues for a first time length, the camera is controlled to focus, and the flash is illuminated, wherein the focus is continued for a second time length, and the focus is turned off. Flash, end exposure, get the target image. Thereby, a background blur image with better effect can be obtained in a dark environment.

FIG. 5 is a schematic structural diagram of a second embodiment of a terminal according to an embodiment of the present invention. The terminal described in this embodiment includes: at least one input device 1000; at least one output device 2000; at least one processor 3000, such as a CPU; and a memory 4000, the input device 1000, the output device 2000, the processor 3000, and the memory 4000 is connected via bus 5000.

The input device 1000 may be a touch panel, a physical button, or a mouse.

The output device 2000 described above may specifically be a display screen.

The above memory 4000 may be a high speed RAM memory or a non-volatile memory such as a magnetic disk memory. The above memory 4000 is used to store a set of program codes, and the input device 1000, the output device 2000, and the processor 3000 are used to call the program code stored in the memory 4000, and perform the following operations:

The processor 3000 is configured to:

Turning off the flash;

End the exposure and get the target image.

Optionally, the processor 3000 is further configured to: after the turning off the flash, and ending the exposure to obtain a target image, further specifically:

The camera is controlled to continue to defocus for a third length of time.

Optionally, the processor 3000 is further configured to: after the control camera is out of focus and continues to be exposed, and before the controlling the camera to focus and illuminate the flash,

It is detected whether all the photosensitive cells of the image sensor are in an exposure state.

Optionally, before the processor 3000 controls the camera to be out of focus and continues to be exposed, the method further includes:

Controlling the camera to perform pre-focusing to obtain a focus position;

The exposure duration of the exposure and the second length of time are determined.

Optionally, after the processor 3000 turns off the flash, and after the end of the exposure, after obtaining the target image, the method is further specifically configured to:

Perform the following procedure N times, where N is a positive integer:

Turn off the flash.

In a specific implementation, the input device 1000, the output device 2000, and the processor 3000 described in the embodiments of the present invention may perform the first embodiment and the first method of the photographing control method provided by the embodiment of the present invention. The implementations of the terminal described in the first embodiment of the present invention may also be implemented in the implementation manners in the second embodiment and the third embodiment, and details are not described herein again.

The units in all the embodiments of the present invention may be implemented by a general-purpose integrated circuit, such as a CPU (Central Processing Unit), or by an ASIC (Application Specific Integrated Circuit).

The steps in the method of the embodiment of the present invention may be sequentially adjusted, merged, and deleted according to actual needs.

The units in the terminal in the embodiment of the present invention may be combined, divided, and deleted according to actual needs.

One of ordinary skill in the art can understand that all or part of the process of implementing the foregoing embodiments can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium. When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

The photographing control method and the terminal provided by the embodiments of the present invention are described in detail. The principles and embodiments of the present invention are described in the following. The description of the above embodiments is only for helping to understand the present invention. The method and its core idea; at the same time, those skilled in the art, according to the idea of the present invention, there will be changes in the specific implementation and application scope. In summary, the content of the specification should not be understood as Limitations of the invention.

Claims

A photographing control method, comprising:

Controlling the camera to be out of focus and continuously exposing, wherein the defocusing continues for a first length of time;

Controlling the camera to focus, lighting the flash, wherein the focus continues for a second length of time;

Turning off the flash;

End the exposure and get the target image.
The method of claim 1, wherein the method further comprises: after the turning off the flash, and ending the exposure to obtain a target image, the method further comprising:

The camera is controlled to continue to defocus for a third length of time.
The method of claim 1 wherein after the controlling the camera is out of focus and continuing to be exposed, and before the controlling the camera to focus and illuminating the flash, the method further comprises:

It is detected whether all the photosensitive cells of the image sensor are in an exposure state.
The method according to any one of claims 1 to 3, wherein before the controlling the camera is out of focus and continuing exposure, the method further comprises:

Controlling the camera to perform pre-focusing to obtain a focus position;

The exposure duration of the exposure and the second length of time are determined.
The method according to any one of claims 1 to 3, wherein, after the flash is turned off, and the end of the exposure is performed to obtain a target image, the method further comprises:

Perform the following procedure N times, where N is a positive integer:

Controlling the camera to be out of focus, wherein the defocusing continues for a third length of time;

Controlling the camera to focus, lighting the flash, wherein the focus continues for a fourth time length;

Turn off the flash.
A terminal, comprising:

a first control unit, configured to control the camera to be out of focus, and to continue exposure, wherein the defocusing continues for a first length of time;

a second control unit, configured to control the camera to focus, to illuminate the flash, wherein the focus continues for a second length of time;

a closing unit for turning off the flash;

A processing unit for ending the exposure to obtain a target image.
The terminal according to claim 6, wherein the terminal further comprises:

The third control unit is configured to control the camera to continue to defocus for a third time length after the closing unit turns off the flash, and the exposure is ended by the processing unit to obtain a target image.
The terminal according to claim 6, wherein the terminal further comprises:

a first detecting unit, configured to: after the first control unit controls the camera to defocus, and continuously exposes, detecting that all the photosensitive cells of the image sensor are in an exposed state, if the detection result of the first detecting unit is yes, The second control unit controls the camera to focus and illuminate the flash.
The terminal according to any one of claims 6 to 8, wherein the terminal further comprises:

a fourth control unit, configured to control the camera to perform pre-focusing to obtain a focus position before the first control unit controls the camera to defocus and continuously expose;

a determining unit for determining an exposure duration of the exposure and the second length of time.
The terminal according to any one of claims 6 to 8, characterized in that, after the closing unit turns off the flash, and the processing unit ends the exposure to obtain a target image, the first control unit, the The second control unit and the shutdown unit are configured to perform the following process N times, where N is a positive integer:

The first control unit controls the camera to be out of focus, wherein the defocusing continues for a third time length;

The second control unit controls the camera to focus, and illuminates the flash, wherein the focus continues for a fourth time length;

The closing unit turns off the flash.
A terminal, comprising:

a memory storing executable program code;

a processor coupled to the memory;

The processor calls the executable program code stored in the memory, and performs the following steps:

Controlling the camera to be out of focus and continuously exposing, wherein the defocusing continues for a first length of time;

Controlling the camera to focus, lighting the flash, wherein the focus continues for a second length of time;

Turning off the flash;

End the exposure and get the target image.
The terminal according to claim 11, wherein the processor is further configured to: after the turning off the flash, and ending the exposure to obtain a target image, the processor is further configured to:

The camera is controlled to continue to defocus for a third length of time.
The terminal according to claim 11, wherein said processor is further used after said control camera is out of focus and continues to be exposed, and before said controlling said camera to focus and illuminating a flash. to:

It is detected whether all the photosensitive cells of the image sensor are in an exposure state.
The terminal according to any one of claims 11 to 13, wherein the processor is further configured to: before the camera is out of focus and continuously exposed;

Controlling the camera to perform pre-focusing to obtain a focus position;

The exposure duration of the exposure and the second length of time are determined.
The terminal according to any one of claims 11 to 13, wherein said processor is further used after said turning off said flash, and said ending exposure to obtain a target image to:

Perform the following procedure N times, where N is a positive integer:

Controlling the camera to be out of focus, wherein the defocusing continues for a third length of time;

Controlling the camera to focus, lighting the flash, wherein the focus continues for a fourth time length;

Turn off the flash.