CN104506777B - Method and device for controlling flash exposure - Google Patents

Abstract

The invention discloses a method and a device for controlling the exposure of a flash lamp. The method includes: when starting the camera to take pictures, driving the motor of the camera to focus, and obtaining the current motor position after focusing; judging whether the current motor position is within the motor position at the critical point of underexposure or at the overexposure The motor position is outside the critical point; according to the result of the judgment, the sensitivity of the camera is adjusted to control the exposure of the flash. Corresponding devices are also disclosed. The present invention judges whether the current motor position after the camera focuses is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, and adjusts the sensitivity of the camera according to the judgment result to control the exposure of the flashlight , can automatically control the exposure of the flash to prevent the phenomenon of overexposure in the near area and underexposure in the distance.

Description

Method and device for controlling flash exposure

technical field

The invention relates to the technical field of image processing, in particular to a method and device for controlling flash exposure.

Background technique

With the improvement of people's living standards, people like to take photos with professional cameras or terminals with camera functions. However, it is difficult for non-professional photographers to control the exposure of the flash light of the camera. When turning on the flash light on the camera to take pictures, there are The phenomenon of overexposure near and underexposure far away.

Therefore, it is necessary to provide a solution for automatically controlling the exposure of the flashlight to prevent overexposure in the near area and underexposure in the distance.

Contents of the invention

The present invention provides a method and device for controlling the exposure of flash lamps, so as to automatically control the exposure of flash lamps and prevent the phenomenon of overexposure in the near area and underexposure in the distance.

In one aspect, a method of controlling flash exposure is provided, comprising:

When starting the camera to take pictures, drive the motor of the camera to focus, and obtain the current motor position after focusing;

judging whether the current motor position is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure;

According to the judgment result, the sensitivity of the camera is adjusted to control the exposure of the flashlight.

In another aspect, an apparatus for controlling flash exposure is provided, comprising:

The first acquiring unit is used to drive the motor of the camera to focus when starting the camera to take pictures, and acquire the current motor position after focusing;

A judging unit, configured to judge whether the current motor position is within the motor position at the critical point of underexposure or outside the motor position at the critical point of overexposure;

An adjustment unit, configured to adjust the sensitivity of the camera according to the result of the judgment, so as to control the exposure of the flashlight.

It can be seen that according to a method and device for controlling flash exposure provided by the present invention, by judging whether the current motor position after the camera focuses is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, according to As a result of the judgment, adjust the sensitivity of the camera to control the exposure of the flash, which can automatically control the exposure of the flash to prevent the phenomenon of overexposure in the near area and underexposure in the distance.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a schematic flowchart of a method for controlling flash exposure provided by an embodiment of the present invention;

FIG. 2 is a schematic flow diagram of a further refinement of a method for controlling flash lamp exposure provided by the embodiment of the present invention shown in FIG. 1;

FIG. 3 is a schematic structural diagram of a device for controlling flash exposure provided by an embodiment of the present invention;

FIG. 4 is a further detailed structural schematic diagram of a device for controlling flash exposure provided by the embodiment of the present invention shown in FIG. 3 .

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without creative efforts fall within the protection scope of the present invention.

Please refer to FIG. 1 , which is a schematic flowchart of a method for controlling flash exposure provided by an embodiment of the present invention. The method includes the following steps:

Step S101 , when the camera is started to take pictures, the motor of the camera is driven to focus, and the current motor position after focusing is obtained.

The camera involved in the embodiment of the present invention may be a professional camera such as a digital camera, or a terminal with a camera function such as a mobile phone or a tablet computer. When the camera is started to take pictures, it will perform a focusing process. The process of focusing is to drive the motor of the camera to move the position to focus. After focusing, obtain the current motor position.

Step S102 , judging whether the current motor position is within the motor position of the underexposure critical point or outside the overexposure critical point motor position.

When focusing, the motor may move to a position closer to the focus, or it may move to a position farther from the focus. Then, the sensitivity (ISO) of the camera is determined according to multiple parameters such as the surrounding environment. If the current motor If the position is too close to the focus, there will be overexposure of the flash; if the current motor position is too far from the focus, there will be underexposure of the flash. Therefore, it may first be determined whether the current motor position after focusing is within the under-exposure critical point motor position or outside the over-exposure critical point motor position.

Step S103, adjusting the sensitivity of the camera to control the exposure of the flash according to the result of the determination.

According to the judgment result, that is, the current motor position after focusing is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, adjust the sensitivity of the camera, specifically reduce or increase the sensitivity of the camera to prevent close overexposure or long distance underexposure; of course, if the current motor position after focusing is between the underexposure critical point motor position and the overexposure critical point motor position, there is no need to readjust the camera sensitivity.

According to a method for controlling flash exposure provided by the present invention, by judging whether the current motor position after the camera focuses is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, according to the judgment result, Adjust the sensitivity of the camera to control the exposure of the flash, which can automatically control the exposure of the flash to prevent the phenomenon of overexposure in the near area and underexposure in the distance.

Please refer to FIG. 2, which is a schematic flow chart of a further refinement of a method for controlling flash exposure provided by the embodiment of the present invention shown in FIG. 1. The method includes the following steps:

Step S201, before starting the camera to take pictures, test the underexposure and overexposure of the camera, and obtain the motor position of the critical point of underexposure and the motor position of the critical point of overexposure.

First test the overexposure and underexposure position of the current camera, assuming that the overexposure is within 50cm, then record the position_50cm where the motor is at 50cm. Assuming underexposure beyond 150cm, record the position_150cm where the motor is at 150cm.

Step S202, when starting the camera to take pictures, drive the motor of the camera to focus, and obtain the current motor position after focusing.

Turn on the camera flash to take pictures and record the current motor position position_current.

Step S203, judging whether the current motor position is within the under-exposure critical point motor position or outside the over-exposure critical point motor position; if the current motor position is within the under-exposure critical point If the motor position is within the motor position, go to step S204; if the current motor position is outside the overexposure critical point motor position, go to step S205.

Step S204, if the current motor position is within the underexposure threshold motor position, reduce the sensitivity of the camera to prevent the flash from overexposure.

If position_current<position_50cm, multiply the ISO of the flash photo by this ratio: position_current/position_50cm to reduce the brightness. which is:

ISO ₂ = ISO ₁ *position_current/position_50cm

Among them, ISO ₁ is the sensitivity determined by the camera according to multiple parameters such as the surrounding environment before adjusting the flash exposure, and ISO ₂ is the sensitivity of the camera after adjusting the flash exposure.

Step S205 , if the current motor position is outside the overexposure threshold motor position, increase the sensitivity of the camera to prevent underexposure of the flash.

If position_current>position_150cm, multiply ISO by position_150cm/position_current to increase brightness. which is:

ISO ₃ = ISO ₁ *position_150cm/position_current

Among them, ISO ₃ is the sensitivity of the camera after adjusting the flash exposure.

Write the adjusted ISO into the camera's register to control the brightness of the exposure. In this way, the brightness within 50cm can be reduced, and the brightness beyond 150cm can be increased, so as to achieve the purpose of not under-exposing near and not under-exposure at a distance.

According to a method for controlling flash exposure provided by the present invention, by judging whether the current motor position after the camera focuses is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, according to the judgment result, Adjust the sensitivity of the camera to control the exposure of the flash, which can automatically control the exposure of the flash to prevent the phenomenon of overexposure in the near area and underexposure in the distance.

Please refer to FIG. 3 , which is a schematic structural diagram of a device for controlling flash exposure provided by an embodiment of the present invention. The device 1000 includes:

The first acquiring unit 11 is configured to drive the motor of the camera to focus when the camera is started to take pictures, and acquire the current motor position after focusing.

The camera involved in the embodiment of the present invention may be a professional camera such as a digital camera, or a terminal with a camera function such as a mobile phone or a tablet computer. When the camera is started to take pictures, it will perform a focusing process. The process of focusing is to drive the motor of the camera to move the position to focus. After the first acquisition unit 11 focuses, it acquires the current motor position.

The judging unit 12 is configured to judge whether the current motor position is within the motor position at the critical point of underexposure or outside the motor position at the critical point of overexposure.

When focusing, the motor may move to a position closer to the focus, or it may move to a position farther from the focus. Then, the sensitivity (ISO) of the camera is determined according to multiple parameters such as the surrounding environment. If the current motor If the position is too close to the focus, there will be overexposure of the flash; if the current motor position is too far from the focus, there will be underexposure of the flash. Therefore, the judging unit 12 may first judge whether the current motor position after focusing is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure.

The adjustment unit 13 is configured to adjust the sensitivity of the camera according to the result of the judgment, so as to control the exposure of the flashlight.

The adjustment unit 13 adjusts the sensitivity of the camera according to the judgment result, that is, the current motor position after focusing is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, specifically reducing or increasing the sensitivity of the camera. The sensitivity of the camera to prevent close-range overexposure or long-range underexposure; of course, if the current motor position after focusing is between the underexposure critical point motor position and the overexposure critical point motor position, there is no need Readjust the camera's sensitivity to light.

According to a device for controlling flash exposure provided by the present invention, by judging whether the current motor position after the camera focuses is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, according to the judgment result, Adjust the sensitivity of the camera to control the exposure of the flash, which can automatically control the exposure of the flash to prevent the phenomenon of overexposure in the near area and underexposure in the distance.

Please refer to FIG. 4, which is a further detailed structural schematic diagram of a device for controlling flash exposure provided by the embodiment of the present invention shown in FIG. 3. The device 2000 includes:

The second acquiring unit 21 is configured to test the underexposure and overexposure of the camera before starting the camera to take pictures, and acquire the critical point motor position of underexposure and the critical point motor position of overexposure.

First test the overexposure and underexposure position of the current camera, assuming that the overexposure is within 50cm, then record the position_50cm where the motor is at 50cm. Assuming underexposure beyond 150cm, record the position_150cm where the motor is at 150cm.

The first acquiring unit 22 is configured to drive the motor of the camera to focus when starting the camera to take pictures, and acquire the current motor position after focusing.

Turn on the camera flash to take pictures and record the current motor position position_current.

The judging unit 23 is configured to judge whether the current motor position is within the under-exposed critical point motor position or outside the over-exposed critical point motor position.

The adjustment unit 24 is configured to adjust the sensitivity of the camera according to the judgment result, so as to control the exposure of the flashlight.

In this embodiment, the adjustment unit 24 includes a reduction unit 241 and an increase unit 242 .

The reducing unit 241 is configured to reduce the sensitivity of the camera if the current motor position is within the underexposure threshold motor position, so as to prevent the flash from overexposure.

If position_current<position_50cm, multiply the ISO of the flash photo by this ratio: position_current/position_50cm to reduce the brightness. which is:

ISO ₂ = ISO ₁ *position_current/position_50cm

Among them, ISO ₁ is the sensitivity determined by the camera according to multiple parameters such as the surrounding environment before adjusting the flash exposure, and ISO ₂ is the sensitivity of the camera after adjusting the flash exposure.

The increasing unit 242 is configured to increase the sensitivity of the camera to prevent underexposure of the flash if the current motor position is outside the overexposure threshold motor position.

If position_current>position_150cm, multiply ISO by position_150cm/position_current to increase brightness. which is:

ISO ₃ = ISO ₁ *position_150cm/position_current

Among them, ISO ₃ is the sensitivity of the camera after adjusting the flash exposure.

Write the adjusted ISO into the camera's register to control the brightness of the exposure. In this way, the brightness within 50cm can be reduced, and the brightness beyond 150cm can be increased, so as to achieve the purpose of not under-exposing near and not under-exposure at a distance.

According to a device for controlling flash exposure provided by the present invention, by judging whether the current motor position after the camera focuses is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure, according to the judgment result, Adjust the sensitivity of the camera to control the exposure of the flash, which can automatically control the exposure of the flash to prevent the phenomenon of overexposure in the near area and underexposure in the distance.

It should be noted that for the foregoing method embodiments, for the sake of simple description, they are expressed as a series of action combinations, but those skilled in the art should know that the present invention is not limited by the described action sequence. Because according to the present invention, certain steps may be performed in other order or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present invention.

In the foregoing embodiments, the descriptions of each embodiment have their own emphases, and for parts not described in detail in a certain embodiment, reference may be made to relevant descriptions of other embodiments.

Through the above description of the implementation manners, those skilled in the art can clearly understand that the present invention can be implemented by hardware, firmware, or a combination thereof. When implemented in software, the functions described above may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. Take this as an example but not limited to: computer-readable media may include Random Access Memory (Random Access Memory, RAM), Read-Only Memory (Read-Only Memory, ROM), Electrically Erasable Programmable Read-Only Memory (Electrically Erasable Programmable Read -Only Memory, EEPROM), CD-ROM (Compact Disc Read-Only Memory, CD-ROM) or other optical disk storage, magnetic disk storage medium or other magnetic storage devices, or can be used to carry or store information in the form of instructions or data structures desired program code and any other medium that can be accessed by a computer. also. Any connection can suitably be a computer-readable medium. For example, if the Software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), or wireless technologies such as infrared, radio, and microwave, Coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, wireless and microwave are then included in the fixation of the associated medium. As used herein, Disk and disc include compact disc (CD), laser disc, compact disc, digital versatile disc (DVD), floppy disc, and Blu-ray disc, where discs usually reproduce data magnetically, and discs Lasers are used to optically reproduce the data. Combinations of the above should also be included within the scope of computer-readable media.

In a word, the above descriptions are only preferred embodiments of the technical solutions of the present invention, and are not intended to limit the protection scope of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (8)

1. A method for controlling flash exposure, comprising: When starting the camera to take pictures, drive the motor of the camera to focus, and obtain the current motor position after focusing; judging whether the current motor position is within the motor position of the critical point of underexposure or outside the motor position of the critical point of overexposure; adjusting the sensitivity of the camera to control the exposure of the flash according to the result of the judgment; Specifically, adjusting the sensitivity of the camera to control the exposure of the flash according to the result of the judgment includes: If the current motor position is within the threshold motor position of underexposure, reducing the sensitivity of the camera to prevent overexposure of the flash; If the current motor position is outside the threshold motor position for overexposure, increase the sensitivity of the camera to prevent underexposure of the flash. 2. The method of claim 1, further comprising: Before the camera is started to take pictures, the underexposure and overexposure of the camera are tested to obtain the underexposure critical point motor position and the overexposure critical point motor position. 3. The method of claim 1, wherein if the current motor position is within the threshold motor position for underexposure, reducing the sensitivity of the camera to prevent overexposure of the flash ,include: If the current motor position is within the motor position at the critical point of underexposure, the adjusted sensitivity of the camera is obtained by multiplying the sensitivity of the camera by the current motor position and the threshold of the underexposure Ratio of point motor position. 4. The method of claim 1, wherein if the current motor position is outside the threshold motor position for overexposure, increasing the sensitivity of the camera to prevent the flash from Underexposure, including: If the current motor position is outside the motor position at the critical point of overexposure, the adjusted sensitivity of the camera is obtained by multiplying the sensitivity of the camera by the motor position at the critical point of overexposure and the The ratio of the current motor position. 5. A device for controlling flash exposure, comprising: The first acquiring unit is used to drive the motor of the camera to focus when starting the camera to take pictures, and acquire the current motor position after focusing; A judging unit, configured to judge whether the current motor position is within the motor position at the critical point of underexposure or outside the motor position at the critical point of overexposure; an adjustment unit, configured to adjust the sensitivity of the camera according to the result of the judgment, so as to control the exposure of the flash; Specifically, the adjustment unit includes: a reducing unit, configured to reduce the sensitivity of the camera if the current motor position is within the motor position of the underexposure critical point, so as to prevent the flash from overexposure; An increasing unit, configured to increase the sensitivity of the camera if the current motor position is outside the overexposure threshold motor position, so as to prevent the flash light from underexposure. 6. The device of claim 5, further comprising: The second obtaining unit is configured to test the underexposure and overexposure of the camera before starting the camera to take pictures, and obtain the motor position of the critical point of the underexposure and the motor position of the critical point of the overexposure. 7. The device according to claim 5, wherein the reducing unit is specifically used for: If the current motor position is within the motor position at the critical point of underexposure, the adjusted sensitivity of the camera is obtained by multiplying the sensitivity of the camera by the current motor position and the threshold of the underexposure Ratio of point motor position. 8. The device according to claim 5, wherein the enlarging unit is specifically used for: If the current motor position is outside the motor position at the critical point of overexposure, the adjusted sensitivity of the camera is obtained by multiplying the sensitivity of the camera by the motor position at the critical point of overexposure and the The ratio of the current motor position.