CN104965376B - The adjusting method and system of a kind of terminal camera flash lamp - Google Patents

Abstract

A method and system for adjusting a flashlight of a terminal camera, said method comprising the steps of: Step 1. _Obtaining the camera sensitivity S _high when taking pictures with a normal flashlight; Current I _max ; Step 3. Determine whether the maximum current I _max is greater than the maximum current I _hard supported by the terminal camera, and the maximum current I _hard is a preset fixed value; Step 4. If I _max is greater than the maximum current I _hard supported by the terminal camera, then Set the current to I=I _hard when taking pictures, and reacquire the camera sensitivity S _high ; if I _max is less than or equal to the maximum current I _hard supported by the terminal camera, then perform the next step; Step 5. Set the maximum current I _max and the camera sensitivity to The degree S _high is written into the terminal camera as the current and camera sensitivity parameters, and a flash photo is completed. According to the brightness of the image before and after the pre-flash, the present invention adjusts the current of the flashlight when taking pictures to achieve the purpose of controlling the brightness of the flashlight, so that when the flashlight is turned on, the brightness of the image is consistent to a certain extent and saves power.

Description

Method and system for adjusting flashlight of terminal camera

technical field

The present invention relates to terminal equipment photographing technology, in particular to a terminal camera flash adjustment method and system.

Background technique

A camera is a device that uses the principle of optical imaging to form an image and uses a film to record the image. Many devices capable of recording images have the characteristics of a camera. Medical imaging equipment, astronomical observation equipment, etc. A camera is an optical device used for photography. After the light reflected by the object to be photographed is focused by the photographic lens (objective lens) and the shutter controlling the exposure, the object to be photographed forms a latent image on the photosensitive material in the dark box, which is processed (that is, developed and fixed) to form a permanent image. images, this technique is called photography. Divided into general photography and professional video.

However, existing terminal devices, such as mobile phones and PDAs, generally have a camera function. For example, at present, if the flashlight is turned on when the mobile phone takes a photo, the brightness of the flashlight is the same under any circumstances, which leads to the following deficiencies:

(1) Under different ambient brightness, the same light source is supplemented, resulting in inconsistent image brightness, and the same mobile phone has different effects.

(2) When the mobile phone is very close to the foreground, the flash light hits the foreground very brightly, so the exposure time is very short; but because the flash light cannot provide sufficient light to the background, the background is very dark, and the exposure time is short, which easily leads to bright foreground , the background is dark, resulting in a large visual contrast between light and dark, as shown in Figure 1.

(3) The flash light is opened to the maximum every time, which causes a waste of power, thereby reducing the standby time of the mobile phone.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method and system for adjusting the flashlight of a terminal camera, which can make the brightness of the image consistent and effectively save power.

In order to achieve the above object, the technical scheme adopted in the present invention is:

A method for adjusting a flashlight of a terminal camera, comprising the steps of:

Step 1. Obtain the camera sensitivity S _high when taking pictures with a normal flash;

Step 2. Calculate the maximum current I _max required by the camera when taking pictures according to the camera sensitivity S _high ;

Step 3. Determine whether the maximum current I _max is greater than the maximum current I _hard supported by the terminal camera, and the maximum current I _hard is a preset fixed value;

Step 4. If I _max is greater than the maximum current I _hard supported by the terminal camera, set the current to I=I _hard when taking pictures, and reacquire the camera sensitivity S _high ; if I _max is less than or equal to the maximum current I _hard supported by the terminal camera , then go to the next step;

Step 5. Write the maximum current I _max and camera sensitivity S _high as current and camera sensitivity parameters into the terminal camera to complete a flash photo.

Further, step 1 specifically includes:

Set the picture brightness Luma value in the pre-flash stage and the picture brightness Luma value that needs to be achieved in the photographing stage, and the picture brightness Luma value is the average value of the image brightness Y; set the product of the image sensitivity ISO and the exposure time to be the camera sensitivity Sensitive, assuming The camera sensitivity before the flash is turned on is S ₀ , the camera sensitivity is S _pre during the pre-flash, and the camera sensitivity is S _high when taking pictures;

S101. Obtain the Luma value L ₀ of the screen brightness and the camera sensitivity S ₀ before the flash is turned on, and the current of the flash in the off state is 0 at this time;

S102. Obtain the Luma value L _pre of the image brightness in the pre-flash phase, the current value I _pre in the pre-flash phase, and the camera sensitivity as S _pre ;

S103. Determine whether the camera sensitivity in the pre-flash stage is S _pre and the camera sensitivity S ₀ before the flash is turned on. If they are consistent, the current picture brightness Luma value is The amount of change in the Luma value of the screen brightness caused by the flash pre-flash stage is ΔL=L' _pre -L ₀ ;

S104. Set the current value of the photographing stage to I _snap and the screen brightness Luma value to L _snap . Assuming that the brightness of the flashlight is proportional to the current, the amount of change in the Luma value of the screen brightness caused by the strong flash of the flashlight is When taking pictures, the Luma value of the screen brightness is: L _high = ΔL _high + L ₀ ;

S105. Set the brightness required for taking pictures as Luma is L _target , and L _target is a fixed value, and obtain the camera sensitivity when taking pictures

Further, step 2 specifically includes:

S201. According to ΔL=L' _pre -L ₀ , L _high ＝ΔL _high +L ₀ and The five formulas are converted to get

S202. I _pre , L _pre , S ₀ , S _pre , L ₀ and L _target are fixed values, then the obtained I _snap is a first-order function about S _high ;

S203. Obtain the minimum value of S _high , set it as S _min , and calculate the maximum current I _max required for taking pictures.

Further, step 4 specifically includes:

S401. If I _max is greater than the maximum current I _hard supported by the terminal camera, then perform step S402, and if I _xam is less than or equal to the maximum current I _hard supported by the terminal camera, then perform step 5;

S402.I _max is greater than the maximum current I _hard supported by the terminal camera, and it is determined that the flash is far away from the object and the ambient brightness value is low;

S403. The photographing current is set to I=I _hard ;

S404. Increase camera exposure time or image sensitivity to increase S _high , and recalculate camera sensitivity S _high .

The present invention also discloses an adjustment system for the flashlight of the terminal camera, including:

The camera sensitivity acquisition unit for normal photo taking is used to acquire the camera sensitivity S _high when taking photos with a normal flash;

The maximum current acquisition unit for taking pictures is used to calculate the maximum current I _max required by the camera when taking pictures according to the camera sensitivity S _high ;

A judging unit, configured to judge whether the maximum current I _max is greater than the maximum current I _hard supported by the terminal camera, and the maximum current I _hard is a preset fixed value;

The photographing current setting unit is used for if I _max is greater than the maximum current I _hard supported by the terminal camera, then the current is set to I=I _hard when taking pictures, and the camera sensitivity S _high is reacquired; if I _max is less than or equal to the maximum current I hard supported by the terminal camera maximum current I _hard , then execute the next step;

The storage unit is used to write the maximum current I _max and the camera sensitivity S _high as current and camera sensitivity parameters into the terminal camera to complete a flash photo.

Further, the normal photographing camera sensitivity acquisition unit specifically includes:

Set the picture brightness Luma value in the pre-flash stage and the picture brightness Luma value that needs to be achieved in the photographing stage, and the picture brightness Luma value is the average value of the image brightness Y; set the product of the image sensitivity ISO and the exposure time to be the camera sensitivity Sensitive, assuming The camera sensitivity before the flash is turned on is S ₀ , the camera sensitivity is S _pre during the pre-flash, and the camera sensitivity is S _high when taking pictures;

The first acquisition unit is used to acquire the screen brightness Luma value L ₀ and the camera sensitivity S ₀ before the flash is turned on. At this time, the current of the flash in the off state is 0;

The second acquisition unit is used to obtain the Luma value L _pre of the screen brightness in the pre-flash phase, the current value I _pre in the pre-flash phase, and the camera sensitivity as S _pre ;

The camera sensitivity judging unit is used to judge whether the camera sensitivity in the pre-flash stage is S _pre and the camera sensitivity S ₀ before the flash is turned on. If they are consistent, the current picture brightness Luma value is The amount of change in the Luma value of the screen brightness caused by the flash pre-flash stage is ΔL=L' _pre -L ₀ ;

The setting unit is used to set the current value I _snap and the screen brightness Luma value L _snap in the photographing phase. Assuming that the brightness of the flashlight is proportional to the current, the amount of change in the Luma value of the screen brightness caused by the strong flash of the flashlight is When taking pictures, the Luma value of the screen brightness is: L _high = ΔL _high + L ₀ ;

The camera sensitivity calculation unit is used to set the brightness required for taking pictures as Luma is L _target , and L _target is a fixed value, and obtains the camera sensitivity when taking pictures

Further, the photographing maximum current acquisition unit specifically includes:

The first calculation unit is used according to ΔL=L' _pre -L ₀ , L _high ＝ΔL _high +L ₀ and The five formulas are converted to get

The second calculation unit is used for I _pre , L _pre , S ₀ , S _pre , L ₀ and L _target as fixed values, and then obtains I _snap as a first-order function about S _high ;

The third calculation unit is used to obtain the minimum value of S _high , which is set as S _min , and calculates the maximum current I _max required for taking pictures.

Further, the photographing current setting unit specifically includes:

The analysis unit is used to execute the next step if I _max is greater than the maximum current I _hard supported by the terminal camera, and save the data if I _max is less than or equal to the maximum current I _hard supported by the terminal camera;

The judging unit is used for I _max is greater than the maximum current I _hard supported by the terminal camera, and it is judged that the flashlight is far away from the object and the ambient brightness value is low;

A setting unit is used to set the photographing current to I=I _hard ;

The re-acquisition unit is used to increase the camera exposure time or image sensitivity to increase S _high and recalculate the camera sensitivity S _high .

Compared with the prior art, the beneficial effect of the present invention is: according to the brightness of the image before and after the pre-flash, the current of the flashlight is adjusted to achieve the purpose of controlling the brightness of the flashlight, so that when the flashlight is turned on, to a certain extent Make the brightness of the image consistent and save power.

Description of drawings

Fig. 1 is a flow chart of the adjustment method of the present invention.

detailed description

The following will describe in detail with reference to the accompanying drawings in conjunction with the embodiments, so as to further explain the technical features and advantages of the present invention.

The method flow chart of the present invention is shown in Figure 1, a kind of adjustment method of terminal camera flashlight, comprises the following steps:

Step 1 of the present invention is: obtaining the camera sensitivity S _high when taking pictures with a normal flash light.

As a preferred embodiment of the present invention, step 1 described in the present invention specifically includes:

Set the picture brightness Luma value in the pre-flash stage and the picture brightness Luma value that needs to be achieved in the photographing stage, and the picture brightness Luma value is the average value of the image brightness Y; set the product of the image sensitivity ISO and the exposure time to be the camera sensitivity Sensitive, assuming The camera sensitivity before the flash is turned on is S ₀ , the camera sensitivity is S _pre during the pre-flash, and the camera sensitivity is S _high when taking pictures;

S101. Get the screen brightness Luma value L ₀ and the camera sensitivity S ₀ before the flash is turned on. At this time, the current of the flash in the off state is 0; the values of L ₀ and S ₀ are not fixed, and can be obtained from the system in real time) Turn on the flash The Luma value of the front screen brightness is obtained by obtaining the average value of the screen brightness Y, and the sensitivity is obtained by obtaining the product of the current exposure time and the sensitivity ISO;

S102. Obtain the Luma value L _pre of the screen brightness in the pre-flash phase, the current value I _pre in the pre-flash phase, and the camera sensitivity as S _pre ; the values of L _pre and S _pre are not fixed and can be obtained from the system in real time. The Luma value of the screen brightness is obtained by obtaining the average value of the screen brightness Y, and the camera sensitivity S _pre is obtained by obtaining the product of the current exposure time and the sensitivity ISO, and the current value of the pre-flash stage is fixed and preset by the system;

S103. Determine whether the camera sensitivity in the pre-flash stage is S _pre and the camera sensitivity S ₀ before the flash is turned on. If they are consistent, the current picture brightness Luma value is The amount of change in the Luma value of the screen brightness caused by the flash pre-flash stage is ΔL=L' _pre -L ₀ ;

S104. Set the current value of the photographing stage as I _snap , the screen brightness Luma value as L _snap , (the values of I _snap and L _snap , the screen brightness Luma value L _snap in these two values is considered to be set, and I _snap is the value to be calculated, and step S104 is a guessing process, inferring the calculation setting of each value) Assuming that the brightness of the flashlight is proportional to the current, the amount of change in Luma value of the screen brightness caused by the strong flash of the flashlight is When taking pictures, the Luma value of the screen brightness is: L _high = ΔL _high + L ₀ ;

S105. Set the brightness required for taking pictures as Luma is L _target , and L _target is a fixed value, and obtain the camera sensitivity when taking pictures

Step 2 of the present invention is: calculating the maximum current I _max required by the camera when taking pictures according to the camera sensitivity S _high .

As a preferred embodiment of the present invention, step 2 described in the present invention specifically includes:

S201. According to ΔL=L' _pre -L ₀ , L _high ＝ΔL _high +L ₀ and The five formulas are converted to get

S202. I _pre , L _pre , S ₀ , S _pre , L ₀ and L _target are fixed values, then the obtained I _snap is a first-order function about S _high ;

S203. Obtain the minimum value of S _high , set it as S _min , and calculate the maximum current I _max required for taking pictures.

Step 3 of the present invention is: judging whether the maximum current I _max is greater than the maximum current I _hard supported by the terminal camera, and the maximum current I _hard is a preset fixed value.

Step 4 of the present invention is: if I _max is greater than the maximum current I _hard supported by the terminal camera, then set the current to I=I _hard when taking pictures, and reacquire the camera sensitivity S _high ; if I _max is less than or equal to the maximum current I hard supported by the terminal camera If the maximum current I _hard , go to step 5.

As a preferred embodiment of the present invention, step 4 of the present invention specifically includes:

S401. If I _max is greater than the maximum current I _hard supported by the terminal camera, then perform step S402, and if I _xam is less than or equal to the maximum current I _hard supported by the terminal camera, then perform step 5;

S402.I _max is greater than the maximum current I _hard supported by the terminal camera, and it is determined that the flash is far away from the object and the ambient brightness value is low;

S403. The photographing current is set to I=I _hard ;

S404. Increase camera exposure time or image sensitivity to increase S _high , and recalculate camera sensitivity S _high .

Step 4 of the present invention is: write the maximum current I _max and the camera sensitivity S _high as current and camera sensitivity parameters into the terminal camera, and complete a flash photography.

The flow process of the specific embodiment of the present invention is as follows:

Generally, the brightness of the flash lamp in the pre-flash stage is weak and the brightness is fixed, that is, the current provided to the flash lamp in the pre-flash stage is fixed, so according to the Luma value of the picture in the pre-flash stage (that is, the average value of the image brightness Y), And the Luma value to be achieved in the photographing stage to infer the brightness value of the flash light in the photographing stage, that is, the current value in the photographing stage, so as to achieve the purpose of controlling the brightness of the flash lamp. Specific steps are as follows:

The product of the image sensitivity value ISO and the exposure time T is called the camera sensitivity Sensitive, assuming that the Sensitive before taking a photo is S ₀ , it is S _pre during pre-flash, and it is S _high when taking a photo. The first is the process of calculating S _high when taking pictures with a normal flash.

(1) Obtain the brightness Luma=L ₀ of the picture before taking pictures, and at this time, the current of the flash light in the off state is 0;

(2) Then obtain the current value I _{pre of the pre-flash stage and the screen Luma value L pre ;}

(3) If the pre-flash stage is consistent with the camera sensitivity before the flash is turned on, the current screen brightness is Luma variation of screen brightness caused by flash pre-flash ΔL=L' _pre -L ₀ ;

(4) If the current value when taking pictures is I _snap and the screen brightness Luma is L _snap , assuming that the brightness of the flash is proportional to the current, and the camera sensitivity is the same as that of the camera when taking pictures, then the change in screen brightness caused by the strong flash of the flash is Thus, the brightness of the picture when taking pictures is obtained: L _high = ΔL _high + L ₀ ;

(5) Set the brightness required for taking pictures as Luma Target, set it as L _target ,

(6) The above is the process of calculating S _high when taking pictures with a flash. According to the above formula, the conversion is Except for S _high on the right side of the formula, the others are fixed parameters, or fixed values measured during the photographing process, so that I _snap is a first-order function of S _high ;

(7) First, S _high takes the minimum value S _min , and calculates the maximum current I _max required for taking pictures;

(8) If I _max is greater than the maximum current I _hard supported by the hardware, it means that under the current camera sensitivity, the maximum current of the flash is not enough to take a bright enough photo (the object is far away and the ambient brightness is low). At this time, the camera current is taken as I=I _hard , then recalculate S _high to increase S _high , that is, increase the exposure time or ISO of the camera;

(9) If I _max is less than the maximum current I _hard supported by the hardware, it means that under the camera sensitivity S _min , to take a photo with a brightness of L _target , the flash only needs a current of I _max (the closer the distance, the higher the ambient brightness , the smaller I _max );

(10) According to the above calculated I _max and S _high , write the current and camera sensitivity parameters into the flash hardware and the camera module, and complete a flash photography.

In the case of turning on the flash, the present invention automatically selects the current of the flash when taking pictures according to the brightness change of the image before and after the pre-flash, and does not need to turn on the current of the flash to the maximum each time, thereby achieving the purpose of power saving in the case of flashing. At the same time, when the hardware current is sufficient to brighten the image, the current sensitivity can be directly used for exposure without adjusting the exposure value, thus saving time for taking pictures.

The present invention also discloses an adjustment system for the flashlight of the terminal camera, including:

The camera sensitivity acquisition unit for normal photo taking is used to acquire the camera sensitivity S _high when taking photos with a normal flash;

The maximum current acquisition unit for taking pictures is used to calculate the maximum current I _max required by the camera when taking pictures according to the camera sensitivity S _high ;

A judging unit, configured to judge whether the maximum current I _max is greater than the maximum current I _hard supported by the terminal camera, and the maximum current I _hard is a preset fixed value;

The photographing current setting unit is used for if I _max is greater than the maximum current I _hard supported by the terminal camera, then the current is set to I=I _hard when taking pictures, and the camera sensitivity S _high is reacquired; if I _max is less than or equal to the maximum current I hard supported by the terminal camera maximum current I _hard , then execute the next step;

The storage unit is used to write the maximum current I _max and the camera sensitivity S _high as current and camera sensitivity parameters into the terminal camera to complete a flash photo.

Further, the normal photographing camera sensitivity acquisition unit specifically includes:

Set the picture brightness Luma value in the pre-flash stage and the picture brightness Luma value that needs to be achieved in the photographing stage, and the picture brightness Luma value is the average value of the image brightness Y; set the product of the image sensitivity ISO and the exposure time to be the camera sensitivity Sensitive, assuming The camera sensitivity before the flash is turned on is S ₀ , the camera sensitivity is S _pre during the pre-flash, and the camera sensitivity is S _high when taking pictures;

The first acquisition unit is used to acquire the screen brightness Luma value L ₀ and the camera sensitivity S ₀ before the flash is turned on. At this time, the current of the flash in the off state is 0;

The second acquisition unit is used to obtain the Luma value L _pre of the screen brightness in the pre-flash phase, the current value I _pre in the pre-flash phase, and the camera sensitivity as S _pre ;

The camera sensitivity judging unit is used to judge whether the camera sensitivity in the pre-flash stage is S _pre and the camera sensitivity S ₀ before the flash is turned on. If they are consistent, the current picture brightness Luma value is The amount of change in the Luma value of the screen brightness caused by the flash pre-flash stage is ΔL=L' _pre -L ₀ ;

The setting unit is used to set the current value I _snap and the screen brightness Luma value L _snap in the photographing phase. Assuming that the brightness of the flashlight is proportional to the current, the amount of change in the Luma value of the screen brightness caused by the strong flash of the flashlight is When taking pictures, the Luma value of the screen brightness is: L _high = ΔL _high + L ₀ ;

The camera sensitivity calculation unit is used to set the brightness required for taking pictures as Luma is L _target , and L _target is a fixed value, and obtains the camera sensitivity when taking pictures

Further, the photographing maximum current acquisition unit specifically includes:

The first calculation unit is used according to ΔL=L' _pre -L ₀ , L _high ＝ΔL _high +L ₀ and The five formulas are converted to get

The second calculation unit is used for I _pre , L _pre , S ₀ , S _pre , L ₀ and L _target as fixed values, and then obtains I _snap as a first-order function about S _high ;

The third calculation unit is used to obtain the minimum value of S _high , which is set as S _min , and calculates the maximum current I _max required for taking pictures.

Further, the photographing current setting unit specifically includes:

The analysis unit is used to execute the next step if I _max is greater than the maximum current I _hard supported by the terminal camera, and save the data if I _max is less than or equal to the maximum current I _hard supported by the terminal camera;

The judging unit is used for I _max is greater than the maximum current I _hard supported by the terminal camera, and it is judged that the flashlight is far away from the object and the ambient brightness value is low;

A setting unit is used to set the photographing current to I=I _hard ;

The re-acquisition unit is used to increase the camera exposure time or image sensitivity to increase S _high and recalculate the camera sensitivity S _high .

The present invention is clearly and completely described through the technical solutions in the above embodiments, and it is obvious that the described embodiments are part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

Claims (6)

1. a kind of adjusting method of terminal camera flash lamp, comprises the following steps：

Step 1. obtains camera sensitivity S when normal flash lamp is taken pictures_high；

Step 2. is according to camera sensitivity S_highCalculate the maximum current I needed for camera when taking pictures_max；

Step 3. judges maximum current I_maxWhether maximum current I that terminal camera support is more than_hard, maximum current I_hardIt is default Fixed value；

If step 4. I_maxThe maximum current I supported more than terminal camera_hard, then electric current is set to I=I when will take pictures_hard, again Obtain camera sensitivity S_high；If I_maxThe maximum current I supported less than or equal to terminal camera_hard, then next step is performed；

Step 5. is by maximum current I_maxAnd camera sensitivity S_highIt is complete as electric current and camera sensitivity parameter read-in terminal camera Taken pictures into a flash lamp；

Step 1 is specifically included：

The picture brightness Luma values that preflashing stage picture brightness Luma values and the stage of taking pictures need to reach, the picture brightness are set Luma values are brightness of image Y average value；It is camera sensitivity to set image sensitive degree ISO and the product of time for exposure Sensitive, it is assumed that the camera sensitivity Sensitive before flash lamp is opened is S₀, preflashing when camera sensitivity be S_pre, clap According to when camera sensitivity be S_high；

S101. picture brightness Luma values L before flash lamp is opened is obtained₀And camera sensitivity S₀, now flash lamp be closed Electric current be 0；

S102. preflashing stage picture brightness Luma values L is obtained_pre, the preflashing stage current value I_preAnd camera sensitivity is S_pre；

S103. judge preflashing stage camera sensitivity for S_preCamera sensitivity S before being opened with flash lamp₀It is whether consistent, unanimously Then current picture brightness Luma values areThe pre flashing of flash lamp stage causes picture brightness Luma value changes amount to be Δ L=L'_pre-L₀；

S104. the current value for setting the stage of taking pictures is I_snap, picture brightness Luma values be L_snap, it is assumed that brightness of flash lamp and electric current It is directly proportional, dodging caused picture brightness Luma value changes amounts by force by flash lamp isPicture is bright when taking pictures Spending Luma values is：L_high=Δ L_high+L₀；

S105. it is L as Luma to set brightness needed for taking pictures_target, and L_targetFor definite value, camera sensitivity when acquisition is taken pictures

2. the adjusting method of terminal camera flash lamp according to claim 1, it is characterised in that step 2 is specifically included：

S201. basisΔ L=L'_pre-L₀、L_high=Δ L_high+L₀AndFive formula scales are obtained

S202.I_pre、L_pre、S₀、S_pre、L₀And L_targetFor fixed value, then I is obtained_snapFor on S_highFunction of first order；

S203. S is obtained_highMinimum value, be set to S_min, calculate maximum current I needed for taking pictures_max。

3. the adjusting method of terminal camera flash lamp according to claim 2, it is characterised in that step 4 is specifically included：

If S401. I_maxThe maximum current I supported more than terminal camera_hardStep S402 is then performed, if I_xamLess than or equal to terminal The maximum current I that camera is supported_hardThen perform step 5；

S402.I_maxThe maximum current I supported more than terminal camera_hard, it is determined as flash lamp from far object distance, and ambient brightness Value is low；

S403. the electric current that will take pictures is set to I=I_hard；

S404. increase camera exposure time or image sensitive degree, make S_highIncrease, recalculates camera sensitivity S_high。

4. a kind of regulating system of terminal camera flash lamp, it is characterised in that including：

Normal photographing camera sensitivity acquiring unit, for obtaining camera sensitivity S when normal flash lamp is taken pictures_high；

Take pictures maximum current acquiring unit, for according to camera sensitivity S_highCalculate the maximum current needed for camera when taking pictures I_max；

Judging unit, for judging maximum current I_maxWhether maximum current I that terminal camera support is more than_hard, maximum current I_hardFor predetermined fixed value；

Take pictures current setting unit, if for I_maxThe maximum current I supported more than terminal camera_hard, then electric current is set when will take pictures It is set to I=I_hard, reacquire camera sensitivity S_high；If I_maxThe maximum current I supported less than or equal to terminal camera_hard, Then perform next step；

Memory cell, for by maximum current I_maxAnd camera sensitivity S_highIt is used as electric current and camera sensitivity parameter read-in terminal Camera, completes a flash lamp and takes pictures；

Normal photographing camera sensitivity acquiring unit is specifically included：

The picture brightness Luma values that preflashing stage picture brightness Luma values and the stage of taking pictures need to reach, the picture brightness are set Luma values are brightness of image Y average value；It is camera sensitivity to set image sensitive degree ISO and the product of time for exposure Sensitive, it is assumed that the camera sensitivity Sensitive before flash lamp is opened is S₀, preflashing when camera sensitivity be S_pre, clap According to when camera sensitivity be S_high；

First acquisition unit, for obtaining picture brightness Luma values L before flash lamp is opened₀And camera sensitivity S₀, now flash lamp The electric current being closed is 0；

Second acquisition unit, for obtaining preflashing stage picture brightness Luma values L_pre, the preflashing stage current value I_preAnd camera Sensitivity is S_pre；

Camera sensitivity judging unit, for judging preflashing stage camera sensitivity for S_preCamera sense before being opened with flash lamp Luminosity S₀Whether consistent, unanimously then current picture brightness Luma values areThe pre flashing of flash lamp stage causes picture Brightness Luma value changes amount is Δ L=L'_pre-L₀；

Setting unit, the current value for setting the stage of taking pictures is I_snap, picture brightness Luma values be L_snap, it is assumed that flash lamp is bright Degree is directly proportional to electric current, dodges caused picture brightness Luma value changes amounts by force by flash lamp and isTake pictures When picture brightness Luma values be：L_high=Δ L_high+L₀；

Camera sensitivity computing unit, is L as Luma for setting required brightness of taking pictures_target, and L_targetFor definite value, acquisition is taken pictures Shi Xiangji sensitivity

5. the regulating system of terminal camera flash lamp according to claim 4, it is characterised in that maximum current of taking pictures is obtained Unit is specifically included：

First computing unit, for basisΔ L=L'_pre-L₀、L_high=Δ L_high+L₀AndFive formula scales are obtained

Second computing unit, for I_pre、L_pre、S₀、S_pre、L₀And L_targetFor fixed value, then I is obtained_snapFor on S_highOne Rank function；

3rd computing unit, for obtaining S_highMinimum value, be set to S_min, calculate maximum current I needed for taking pictures_max。

6. the regulating system of terminal camera flash lamp according to claim 5, it is characterised in that current setting unit of taking pictures Specifically include：

Analytic unit, if for I_maxThe maximum current I supported more than terminal camera_hardNext step is then performed, if I_maxIt is less than or waits The maximum current I supported in terminal camera_hardThen preserve data；

Identifying unit, for I_maxThe maximum current I supported more than terminal camera_hard, it is determined as flash lamp from far object distance, and Ambient brightness value is low；

Setting unit, for that will take pictures, electric current is set to I=I_hard；

Unit is reacquired, for increasing camera exposure time or image sensitive degree, makes S_highIncrease, recalculates camera photosensitive Spend S_high。