JP2001094867A - Method and device for correcting backlight of camera - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a conventional problem such that backlight correction can not be applied to a subject deviated from the center of a picture because one picture is divided into plural areas in the backlight correction, weight is previously set up to a fixed value so as to execute the backlight correction of each divided area in accordance with the luminance of a subject existing on the center part, for example, and backlight correction considering the weight is executed. SOLUTION: One picture is divided into plural areas in the backlight correction, a low luminance averaging means 19 averages luminance integration values obtained by integrating the luminance signals of these divided areas in each area, compares the average value with the integration value of each area, extracts integration values equal to or less than the average value and the number of the luminance integration values, and averages the extracted integration values to set up the luminance value of a subject. A reference value changing means 21 changes a reference value for the luminance of the subject on the basis of the extracted number of luminance integration values and drives an iris in an opening direction when the luminance of the subject is smaller than the reference value as the result of comparison by a comparing means 20 or drives the iris in the closing direction when the luminance of the subject is larger than the reference value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera backlight correction device using an image pickup device having an electronic shutter function and a method thereof.

[0002]

2. Description of the Related Art In general, a camera configuration will be described with reference to FIG.

[0003] 1 is a CCD serving as an image sensor, 2 is a CCD 1
An openable and closable iris having a lens for imaging light on the top,
3 is a pre-processing means, 4 is a CCD processed by the pre-processing means 3
This is a YC separation unit that separates the output signal from 1 into a color signal, that is, a luminance signal (Y signal) and color signals (Cr signal, Cb signal).

The preprocessing means 3 includes a sample processing section (CDS) 3a for performing correlated double sampling processing on an output signal captured by the CCD 1, and a gain adjustment for automatically controlling the gain of the signal after the sample processing. It has an automatic gain controller (AGC) 3b as a means and an A / D converter 3c for converting a gain-controlled signal into a digital signal because the signal is an analog signal.

5 is a Y processing means for performing signal processing such as addition of a horizontal synchronizing signal and a vertical synchronizing signal to the Y signal separated by the YC separating means 4 and outputting a Y signal of a video output signal;
Reference numeral 6 denotes a C process unit that generates an RGB signal of a video output signal from the Y signal and the color signal separated by the YC separation unit 4.

Reference numeral 7 denotes a vertical blanking period detecting means for detecting a vertical blanking period added by the Y process means 5, and 8 denotes divided areas a to p obtained by dividing one screen into 8 × 8 (64) as shown in FIG. Area integrating means for integrating the signal level of each luminance signal to calculate an integrated luminance value; 9 operating means for switching the iris setting between normal and backlight;
Is switching means for switching the connection to a simple average calculating means and a weighted average calculating means described later based on the iris setting set by the operating means.

[0007] Reference numeral 11 denotes a connection through the switching means 10 when the iris setting is set to normal by the operation means 9, and when the vertical blanking period is detected by the vertical blanking period detecting means 7, the area integrating means 8 operates. Each calculated divided area a
A simple average calculating means 12 for adding and integrating the luminance integrated values of p to p to calculate a luminance average value. The simple average calculating means 12 is connected via the switching means 10 when the iris setting is normally set by the operation means 9, and the vertical blanking is performed. When the period detecting means 7 detects the vertical blanking period, the luminance integrated value of each of the divided areas a to p calculated by the area integrating means 8 is determined by taking into account the weight according to the preset divided area position. It is a weighted average calculating means for adding and averaging to calculate an average luminance value.

A comparison means 13 compares the average luminance value calculated by the simple average calculation means 11 or the weighted average calculation means 12 with a predetermined value, and 14 opens and closes the iris 2 according to the result of the comparison means 13. This is an iris control unit for controlling.

Reference numeral 15 denotes a gain control means for controlling the gain of the AGC 3b in accordance with the result of the comparison by the comparison means 13 and the control of the luminance control means to be described later. This is a brightness control unit that opens the iris 2 to the maximum and instructs the gain control unit 15 to increase the gain of the AGC 3b when trying to further brighten the screen image.

The gain control means 15 operates so as to decrease the gain of the AGC 3b if the result of the comparison by the comparing means 13 is larger than a predetermined value, and to increase the gain if it is smaller than the predetermined value. Further, the gain control means 15
When the gain of has reached a minimum and is going to decrease further,
It instructs the brightness control means 16 to operate to close the iris 2. Further, as a result of the comparison by the comparing means 13, the iris control means 14 operates the iris 2 in a direction to open if it is smaller than a predetermined value, and operates the iris 2 in a direction to close the iris 2 if it is larger than the predetermined value.

The operation will be described with reference to FIGS.

First, in step S50, it is determined whether the vertical blanking period detecting means 7 has detected a vertical blanking period. If not detected, the process proceeds to step S51, and if detected, the process proceeds to step S53.

In step S51, video output signals (Y signal and RG
B signal). In step S52, the area integrating means 8 integrates the Y signal levels of each area. Thereafter, the process returns to step S50.

In step S53, since the vertical blanking period has been detected, the brightness integration value integrated for each divided area by the area integration means 8 is averaged to calculate a brightness average value. In step S54, the operation means 9 determines whether the iris setting is normal or backlight. If the setting is normal, the process proceeds to step S55. In step S55, the switching means 10 connects to the simple average calculation means 11. Then, in step S56, the simple average calculating means 11 simply adds the integrated luminance values of the respective regions and divides the sum by 64 to calculate an average luminance value.

If it is determined in step S54 that the backlight is set, the process proceeds to step S57. In step S57, the switching means 10 connects to the weighted average calculating means 12.
Then, in step S58, the weighted average calculating means 1
In step 2, the luminance integrated value of each area multiplied by a weighting constant preset according to the position of the divided area is added and averaged to calculate an average luminance value.

The above steps S56 and S58
After executing step S59, the process proceeds to step S59.

In step S59, the brightness control means 16 determines whether or not the iris 2 is currently fully opened under the control of the iris control means 14. If not, the process proceeds to step S60.

In step S60, the comparing means 13 determines whether the average luminance value is smaller than a predetermined value. If it is determined that it is smaller, the process proceeds to step S61, and the iris control unit 14 drives the iris 2 in the opening direction. If it is determined in step S60 that it is not small, step S62
Move to.

In step S62, it is determined whether the average luminance value is larger than a predetermined value. When it is judged to be big,
The process proceeds to step S63, and the iris control unit 14 drives the iris in the closing direction. Step S62
When it is determined that is not large, the iris 2 is not driven because the predetermined value is equal to the average luminance value.

In step S59, the brightness control means 1
When it is determined that the iris 2 is at the maximum opening, step S
Move to 64. In step S64, the comparing means 13 determines whether or not the average luminance value is smaller than a predetermined value. When it is determined that it is smaller, the process proceeds to step S65, and the gain of the AGC 3b is increased by the gain controller 15 according to the signal from the brightness controller 16 and the comparison result from the comparator 13.

Further, when it is determined in step S64 that the average luminance value is not smaller than the predetermined value, the process proceeds to step S66. In step S66, it is determined whether or not the average luminance value is larger than a predetermined value. If it is determined that the gain is large, the process proceeds to step S67, and the gain control unit 15 determines whether the gain of the AGC 3b is minimum. If the gain is the minimum, the gain cannot be further reduced, so the process proceeds to step S63,
The gain control unit 15 instructs the luminance control unit 16 to operate to close the iris 2. Step S6
If it is determined in step S7 that the gain is not the minimum, step S68
Then, the gain control means 15 decreases the gain of the AGC 3b.

If it is determined in step S66 that the average luminance value is not larger than the predetermined value, the gain control means 15 does not increase or decrease the gain of the AGC 3b because the predetermined value is equal to the average luminance value.

The iris control is performed by repeating the above operation.

[0024]

According to the above-described operation, when the image shown in FIG. 4 is captured, when the normal setting is performed by the operation means 9, since the brightness of the sun is high as shown in FIG. Someone turns black and shades. In order to improve this state, the backlight setting is performed by the operation means 9,
Perform backlight correction. At this time, the image output has no background contrast as shown in FIG. 9B, but the brightness of the subject is secured and the state of the subject can be photographed.

However, when the backlight is corrected, the weight added to the divided area is fixed, so that an object out of the center of the screen is in the same state as in the case where the backlight is not corrected as shown in FIG. 9C. In this case, the backlight cannot be corrected.

The present invention has been made to solve such a problem.

[0027]

According to the present invention, there is provided a backlight correcting apparatus for a camera, comprising: an image sensor, an iris that opens and closes to adjust an exposure amount of the image sensor, and a gain of an output signal from the image sensor. Area adjustment means for dividing one screen into a plurality of areas, and integrating the signal level of the luminance signal for each area,
Integrated brightness averaging means for calculating a brightness average value of the integrated value of the signal level of each area integrated by the area integration means; and a brightness average value calculated by the integrated brightness averaging means and a value of each area integrated by the area integration means. A low-luminance averaging unit that calculates only a low-luminance average value by extracting only the integrated value equal to or less than the luminance average value and compares the low-luminance average value calculated by the low-luminance average unit with a predetermined value. Comparison means, as a result of comparison by the comparison means, if the low luminance average value is smaller than a predetermined value, the iris is operated to open, and if the low luminance average value is larger than a predetermined value, the iris is closed. Iris control means for operating.

Further, instead of the iris control means,
As a result of the comparison by the comparing means, if the low luminance average value is smaller than a predetermined value, the gain of the gain adjusting means is increased, and if the low luminance average value is larger than a predetermined value, the gain of the gain adjusting means is decreased. It is characterized by comprising gain control means.

Further, the invention is characterized in that both the iris control means and the gain control means are provided.

Further, a predetermined value of the comparing means is set according to the number of regions having an integrated value equal to or less than the average luminance value extracted by the low luminance averaging means.

Further, in the backlight correction method for a camera according to the present invention, there is provided an image pickup device, an iris that opens and closes to adjust an exposure amount of the image pickup device, and a gain adjusting means for adjusting a gain of an output signal from the image pickup device. An area integrating step of dividing one screen into a plurality of areas and integrating the signal level of the luminance signal for each area, and the integrated value of the signal level of each area integrated in the area integrating step. An integrated brightness averaging step for calculating an average brightness value, and comparing the brightness average value calculated in the integrated brightness averaging step with the integrated value of each area integrated by the area integration means, and extracting only an integrated value equal to or less than the brightness average value. A low-luminance averaging step of calculating a low-luminance average value, a comparing step of comparing the low-luminance average value calculated in the low-luminance averaging step with a predetermined value, and a ratio of the comparison step. As a result, said iris control step low brightness average value is operated in the opening direction of the iris is smaller than the predetermined value, also to the low-brightness average value is operated in the closing direction the iris is larger than a predetermined value,
It is characterized by having.

Also, instead of the iris control step, as a result of the comparison step, if the low luminance average value is smaller than a predetermined value, the gain of the gain adjusting means is increased, and the low luminance average value is set to a predetermined value. A gain control step of reducing the gain of the gain adjusting means if the value is larger than the value.

[0033] The present invention is characterized in that both the iris control step and the gain control step are provided.

Further, a predetermined value in the comparing step is set according to the number of regions having an integrated value equal to or less than the luminance average value extracted in the low luminance averaging step.

[0035]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. 1, the same components as those in FIG.

Reference numeral 17 denotes an integrated brightness averaging means for averaging the brightness integrated values of the respective areas of the area integrating means 8 to calculate a brightness average value and setting this brightness average value as subject brightness. The switching means switches between connection to the low-luminance averaging means 19 described later and bypassing of the low-luminance averaging means 19 based on the iris setting made.

When a normal object is selected in the iris setting of the operation means 9 when photographing a subject with the sun behind, the switching means 18 makes the subject appear black as shown in FIG. 9C. I will. So, if you set the iris to backlight,
As shown in FIG. 5, although the contrast of the background is small, the subject appears bright. The switching is performed for this purpose.

Numeral 19 compares the integrated average value calculated by the integrated brightness averaging means 17 with the integrated brightness value of each area integrated by the area integrating means 8 to extract an area having a brightness lower than the average value and to determine the number of areas. And low-luminance averaging means for calculating an average of the integrated value degree values (low-luminance average value). The low luminance averaging means 19 changes and sets the calculated low luminance average value to the subject luminance set by the integrated luminance averaging means 17.

Reference numeral 20 denotes comparison means for comparing the subject brightness set by the integrated brightness averaging means 17 or the low brightness averaging means 19 with a subject brightness reference value. As the subject luminance reference value of the comparing means 20, a predetermined value set in advance to obtain an image having a desired brightness is set.

Reference numeral 21 denotes a reference value changing means for changing the subject brightness reference value of the comparing means 20 according to the number of areas having a brightness integrated value equal to or less than the brightness average value extracted by the low brightness averaging means 19.

The reference value changing means 21 increases and changes the subject brightness reference value of the comparing means 20 according to the number of extracted areas. Specifically, assuming that the number of extracted regions is X, the subject luminance reference value is obtained by calculating Expression 1.

[0042]

(Equation 1)

Here, the predetermined value is a subject brightness reference value when the iris setting is normally set by the operation means 9.

Then, the comparing means 20 outputs the comparison result to the iris control means 14 and the gain control means 15.

The operation of the above configuration will be described with reference to FIG.

First, in step S1, it is determined whether the vertical blanking period detecting means 7 has detected a vertical blanking period. If not, the process proceeds to step S2.

In step S2, video output signals (Y signal and RGB signals) from the Y
Signal). In step S3, the area integrating means 8 integrates the Y signal levels of each area. Then step S1
Return to

If a vertical blanking period is detected in step S1, the process proceeds to step S4. In step S4, the integrated brightness averaging means 17 averages the integrated brightness values of the divided areas integrated by the area integrating means 8 to calculate an average brightness value. Then, the calculated average luminance value is set as the subject luminance. In step S5, it is determined whether the setting of the operation means 9 is normal or backlight. If the setting is normal, the process proceeds to step S6. In step S6, the switching means 18 is connected to bypass the low luminance averaging means 19.

When it is determined in step S5 that the backlight is set, the process proceeds to step S7. In step S7, the switching means 18 is switched so that the integrated luminance averaging means 17 and the low luminance averaging means 19 are connected.

In step S8, the low luminance averaging means 19 extracts an area having an integrated luminance value smaller than the average luminance value calculated by the integrated luminance averaging means 17 from the divided areas. In step S9, the number of regions extracted in step S8 is counted. In step S10, step S
The average value (low luminance average value) of the integrated luminance values of the region extracted in 8 is calculated.

In step S11, the reference value changing means 21
To change the subject brightness reference value according to the number of areas counted in step S9. Specifically, the above formula 1 is calculated to calculate and set the subject luminance reference value. After this,
The process proceeds to step S12 to perform iris control.

In step S12, the brightness control means 16 determines whether or not the iris 2 is currently fully opened under the control of the iris control means 14. If not, the process proceeds to step S13.

In step S13, the comparing means 13 calculates the expression 1
It is determined whether or not the average luminance value is smaller than the subject luminance reference value calculated in. If it is determined to be smaller, step S14
Then, the iris control unit 14 drives the iris 2 in the opening direction. If it is determined in step S13 that it is not smaller, the process proceeds to step S15.

In step S15, it is determined whether or not the average luminance value is larger than the subject luminance reference value. When it is determined that the iris is large, the process proceeds to step S16, and the iris control unit 14 drives the iris in the closing direction. If it is determined in step S16 that the iris is not large, the iris 2 is not driven because the subject luminance reference value and the luminance average value are equal.

In step S12, the brightness control means 1
When it is determined that the iris 2 is at the maximum opening, step S
Move to 17. In step S17, the comparing means 13 determines whether or not the average luminance value is smaller than the subject luminance reference value. If it is determined to be smaller, the process proceeds to step S18, and the gain controller 15 increases the gain of the AGC 3b according to the signal from the brightness controller 16 and the comparison result from the comparator 13.

When it is determined in step S17 that the average luminance value is not smaller than the subject luminance reference value, the process proceeds to step S19. In step S19, it is determined whether or not the average luminance value is larger than the subject luminance reference value. If it is determined that the gain is larger, the process proceeds to step S20, and the gain controller 15 determines whether the gain of the AGC 3b has reached the minimum. If the gain is minimum, the process proceeds to step S16, in which the gain control unit 15 instructs the luminance control unit 16 to operate the iris 2 in the closing direction. When it is determined in step S20 that the gain is not minimum, the process proceeds to step S21,
Gain control means 15 decreases the gain of AGC 3b.

If it is determined in step S19 that it is not large, the gain control means 15 does not increase or decrease the gain of the AGC 3b because the subject luminance reference value and the luminance average value are equal.

The backlight correction control is performed by repeatedly performing the operations of steps S1 to S21.

From the above, conventionally, as shown in FIG. 9A, if the subject does not exist in the middle as shown in FIG. 9A, even if the backlight is corrected, the obtained image will be as shown in FIG. Is black, but the iris control is performed according to the low luminance value as in the present invention, so that the backlight correction can work effectively regardless of the position of the subject as shown in FIG.

[0060]

According to the present invention, backlight correction can be performed regardless of where the subject is located.

[Brief description of the drawings]

FIG. 1 is a control block diagram of a camera of the present invention.

FIG. 2 is a view showing an operation flowchart of the camera of the present invention.

FIG. 3 is a view showing an operation flowchart of the camera of the present invention following FIG. 2;

FIG. 4 is a diagram showing an image to be photographed.

FIG. 5 is a diagram showing a captured image when backlight correction according to the present invention is set.

FIG. 6 is a control block diagram of a conventional camera.

FIG. 7 is a diagram showing a control flowchart of a conventional camera.

FIG. 8 is a view showing a control flowchart of the conventional camera following FIG. 7;

9A is a photographed image when FIG. 4 is set to normal iris setting, FIG. 9B is a photographed image when backlight compensation is set, and FIG. FIG. 9 is a diagram illustrating a captured image when backlight correction is set when the image is present at a deviated position.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 CCD 2 Iris 3b Automatic gain control part (AGC) 8 Area integration means 14 Iris control means 15 Gain control means 17 Integrated brightness average value 18 Switching means 19 Low brightness average means 20 Comparison means 21 Reference value change means

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Seiji Okada 2-5-5 Keihanhondori, Moriguchi-shi, Osaka F-term in Sanyo Electric Co., Ltd. (reference) 2H002 CC21 DB14 DB27 EB00 HA04 5C022 AB06 AB12 AC42 AC56 AC69

Claims (8)

[Claims] 1. A camera comprising: an image sensor; an iris that opens and closes to adjust an exposure amount of the image sensor; and a gain adjustment unit that adjusts a gain of an output signal from the image sensor. Area integrating means for dividing into a plurality of areas and integrating the signal level of the luminance signal for each area, and integrated luminance averaging means for calculating the average luminance value of the integrated signal level of each area integrated by the area integrating means And comparing the luminance average value calculated by the integrated luminance average means with the integrated value of each area integrated by the area integration means, and extracting only the integrated value equal to or less than the luminance average value to calculate a low luminance average value. Luminance averaging means, comparing means for comparing the low luminance average value calculated by the low luminance averaging means with a predetermined value, and comparing the iris if the low luminance average value is smaller than a predetermined value. Move in open direction An iris control unit for operating the iris in a direction to close the iris when the low luminance average value is larger than a predetermined value. 2. A camera comprising: an image sensor; an iris that opens and closes to adjust an exposure amount of the image sensor; and a gain adjusting unit that adjusts a gain of an output signal from the image sensor. Area integrating means for dividing into a plurality of areas and integrating the signal level of the luminance signal for each area, and integrated luminance averaging means for calculating the average luminance value of the integrated signal level of each area integrated by the area integrating means And comparing the luminance average value calculated by the integrated luminance average means with the integrated value of each area integrated by the area integration means, and extracting only the integrated value equal to or less than the luminance average value to calculate a low luminance average value. Luminance averaging means, comparison means for comparing the low luminance average value calculated by the low luminance averaging means with a predetermined value, and as a result of the comparison means, if the low luminance average value is smaller than a predetermined value, the gain adjustment is performed. Increase the gain of the means And a gain control means for reducing the gain of the gain adjustment means if the low luminance average value is larger than a predetermined value. 3. A camera comprising: an image sensor; an iris that opens and closes to adjust an exposure amount of the image sensor; and a gain adjusting unit that adjusts a gain of an output signal from the image sensor. Area integrating means for dividing into a plurality of areas and integrating the signal level of the luminance signal for each area, and integrated luminance averaging means for calculating the average luminance value of the integrated signal level of each area integrated by the area integrating means And comparing the luminance average value calculated by the integrated luminance average means with the integrated value of each area integrated by the area integration means, and extracting only the integrated value equal to or less than the luminance average value to calculate a low luminance average value. Luminance averaging means, comparing means for comparing the low luminance average value calculated by the low luminance averaging means with a predetermined value, and comparing the iris if the low luminance average value is smaller than a predetermined value, as a result of the comparison means. Move in the open direction And an iris control means for operating the iris in a direction to close the iris if the low luminance average value is larger than a predetermined value, and a gain adjustment means if the low luminance average value is smaller than a predetermined value as a result of comparison by the comparison means. And a gain control means for increasing the gain of the gain adjustment means and decreasing the gain of the gain adjustment means when the low luminance average value is larger than a predetermined value. 4. The method according to claim 1, wherein the predetermined value of the comparing means is set according to the number of areas having an integrated value equal to or less than the luminance average value extracted by the low luminance averaging means. A backlight compensation device for a camera according to any one of the preceding claims. 5. A camera comprising: an image sensor; an iris that opens and closes to adjust an exposure amount of the image sensor; and a gain adjustment unit that adjusts a gain of an output signal from the image sensor. An area integration step of dividing the area into a plurality of areas and integrating the signal level of the brightness signal for each area; and an integrated brightness averaging step of calculating the average brightness value of the integrated signal level of each area integrated in the area integration step And comparing the luminance average value calculated in the integrated luminance average step with the integrated value of each area integrated by the area integrating means, and extracting only the integrated value equal to or less than the luminance average value to calculate a low luminance average value. A luminance averaging step, a comparing step of comparing the low luminance average value calculated in the low luminance averaging step with a predetermined value, and as a result of the comparison step, the low luminance average value is smaller than a predetermined value. Controlling the iris to open in a direction to open the iris, and operating the iris in a direction to close the iris when the low luminance average value is larger than a predetermined value. 6. A camera comprising: an image sensor; an iris that opens and closes to adjust an exposure amount of the image sensor; and a gain adjusting unit that adjusts a gain of an output signal from the image sensor. An area integration step of dividing the area into a plurality of areas and integrating the signal level of the brightness signal for each area; and an integrated brightness averaging step of calculating the average brightness value of the integrated signal level of each area integrated in the area integration step And comparing the luminance average value calculated in the integrated luminance average step with the integrated value of each area integrated in the area integration step, and extracting only the integrated value equal to or less than the luminance average value to calculate a low luminance average value. A luminance averaging step, a comparing step of comparing the low luminance average value calculated in the low luminance averaging step with a predetermined value, and as a result of the comparison step, the low luminance average value is smaller than a predetermined value. A gain control step of increasing the gain of the gain adjusting means, and decreasing the gain of the gain adjusting means if the low luminance average value is larger than a predetermined value. Correction method. 7. A camera comprising: an image sensor; an iris that opens and closes to adjust an exposure amount of the image sensor; and a gain adjustment unit that adjusts a gain of an output signal from the image sensor. An area integration step of dividing the area into a plurality of areas and integrating the signal level of the brightness signal for each area; and an integrated brightness averaging step of calculating the average brightness value of the integrated signal level of each area integrated in the area integration step And comparing the luminance average value calculated in the integrated luminance average step with the integrated value of each area integrated in the area integration step, and extracting only the integrated value equal to or less than the luminance average value to calculate a low luminance average value. A luminance averaging step, a comparison step of comparing the low luminance average value calculated in the low luminance averaging step with a predetermined value, and as a result of the comparison step, the low luminance average value is smaller than the predetermined value. If it is, the iris is operated in a direction in which the iris is opened, and if the low luminance average value is larger than a predetermined value, the iris is controlled in a direction in which the iris is closed. A gain control step of increasing the gain of the gain adjustment means if the value is smaller than a predetermined value, and decreasing the gain of the gain adjustment means if the low luminance average value is larger than a predetermined value. Backlight correction method. 8. The method according to claim 5, wherein a predetermined value in the comparing step is set according to the number of regions having an integrated value equal to or less than the luminance average value extracted in the low luminance averaging step. The backlight correction method for a camera according to any one of the above.