JP3193456B2 - White balance control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white balance control device used for a video camera or the like, and more particularly, to the detection of a white (achromatic) portion of a subject for white balance control.

[0002]

2. Description of the Related Art A conventional white balance control device used for a video camera or the like is disclosed in, for example, JP-A-2-94.
As described in Japanese Unexamined Patent Publication No. 890, a color difference signal having a level equal to or lower than a predetermined threshold value is used as a color difference signal obtained from an achromatic (white) portion of an imaging subject, thereby extracting an achromatic portion of the imaging subject from the color difference signal. At the same time, a high-luminance portion of the imaging subject is extracted from the luminance signal, a high-luminance achromatic portion of the imaging subject, that is, a white portion is determined from the extraction result, and the color in the white portion is determined from the determination result. The signals are extracted and averaged, and the resulting signal is used to control the white balance circuit for the color signals.

The white balance control device described in Japanese Patent Application Laid-Open No. 2-94890 further controls the white balance as described above for an imaged subject having many white portions. In the case of an imaging subject with a small white portion or an imaging subject with a low signal level, the entire color signal is averaged to obtain a white balance control signal.

Another conventional example is disclosed in, for example,
There is a white balance control device described in U.S. Pat. This is to make the white balance control different depending on the shooting environment such as outdoors, indoors, sunlight, incandescent lamps, fluorescent lamps and the like.

That is, first, the (RB) signal and the (R + B-2Y) signal are obtained by adding and subtracting the color difference signals RY and BY, and the high luminance in the object to be imaged is obtained from these signals and the luminance signal. , The white area is detected, and the (RB) signal and the (R + B-2Y) signal in this area are extracted. The (R−B) signal and the (R + B−2Y) signal extracted in this way are averaged, compared with a reference voltage corresponding to a reference point of white balance control, and then added and subtracted at a predetermined ratio to obtain a primary color. A gain control signal for a variable gain amplifier circuit for amplifying the signals R and B is formed.

In such a configuration, the aperture value of the aperture is detected, and the average value (R-
B) The reference point of the white balance control for the signal is made different. In other words, when the aperture value is large, it is determined that the shooting environment is a sunny outdoor scene with sufficiently high illuminance. In such a case, it is generally expected that the color temperature is high (5000 K or more). The reference point is shifted to a higher color temperature. When the aperture value is small, it is determined that the shooting environment is indoors with low illuminance. In such a case, it is generally expected that the color temperature is low (3000 K or less). Shift to lower color temperature.

The above description relates to natural light. Further, means for determining whether a light source is sunlight, an incandescent lamp, or a fluorescent lamp is provided. The (R + B-2Y) signal is also used to form a gain control signal for the variable gain amplifier circuit. When the signal is not a fluorescent lamp, the (R + B-2Y) signal is cut off.

As described above, the white balance control according to the photographing environment can be performed.

[0009]

Incidentally, even under the same illumination, the amount of incident light varies depending on the reflectance of the object to be imaged, the exposure state of the camera, and the like. At this time, if the imaging subject is chromatic or the white is shifted, both the luminance and the color saturation of the signal system (output) rise and fall in proportion to the amount of incident light. That is, even if the original white shift amount is the same, it is not uniquely determined when it is observed as the color saturation in the signal system.

In the white balance control device described in Japanese Patent Application Laid-Open No. 2-94890, a threshold value for a luminance signal and a threshold value for a color signal for detecting a white portion in an imaging subject are set independently of each other. Little consideration has been given to the above-described correlation between the reflectance (の luminance) of the imaging subject and the color saturation. Therefore, the level of the color difference signal decreases as approaching the threshold on the low luminance side, and even the level of the portion of the color difference signal that is not originally considered to be an achromatic portion is equal to or less than the threshold and becomes an achromatic portion. Would. Accordingly, the range of the achromatic color is substantially expanded, and the detection accuracy of the achromatic portion of the imaging subject is reduced, so that high-precision white balance control is not performed.

In the white balance control device described in Japanese Patent Application Laid-Open No. 2-272892, the photographing environment is determined in two values, such as outdoor or indoor, sunlight, incandescent lamp or fluorescent lamp. The difference tends to increase between the white balance control characteristics set for each of these shooting environments. For this reason, if it is determined from the above-mentioned aperture value or the like that the shooting environment has changed, the white balance control characteristics will suddenly change greatly, and the white balance control operation will become unstable.

[0012] A first object of the present invention is to simply provide a predetermined threshold or less.
The color difference signal at the lower level is
Eliminates the problem of the conventional technology that uses color difference signals obtained from the part, and enables more faithful extraction of white areas regardless of the type of light source
To provide an optimal white balance control device.
Another object of the present invention is to provide a white balance control device capable of improving the extraction accuracy of a white portion even when objects having different reflectances (particularly, gray objects) are mixed.

A second object of the present invention is to provide a white balance control apparatus in which a white balance control is performed stably in response to a change in the photographing environment in the photographing environment adaptive processing control even if the photographing environment changes. Is to do.

[0014]

Means for Solving the Problems] To achieve the above first object, the present invention is generated from an output signal of an imaging element
A white portion extraction means for detecting a signal within the set white portion extraction range of the color difference signals as a signal representing a white portion in the photographing subject; and controlling the white portion extraction means .
Multiple different areas on the color difference plane
Next, the white portion extraction range set by switching
Control means for setting the unit out to detect the white balance deviation from a signal representative of the white portion detected by the white color portion extraction means, in response to the detection result, few of the color signals
Gain of variable gain amplifying means for amplifying at least two color signals
And a white balance setting means for generating a signal for controlling the white balance . In particular, the above restrictions
When extracting white at high brightness, the control means
When extracting white at low brightness by increasing the saturation of the region
Is to reduce the saturation of the region.

In order to achieve the second object, the present invention provides an image pickup system which is based on a plurality of specific photographing environments set in advance.
The imaging environment of the image element is estimated, and the environment is determined according to the estimation result.
Imaging environment estimating means for generating a coefficient and changing the white portion extraction range and the follow-up range of white balance control by the white balance setting means according to the environment coefficient
Is provided.

[0016]

According to the present invention, the setting of the judgment condition for the white portion is not required.
The area representing the condition for extracting the white part for natural light
Area representing the condition of white part extraction for artificial lighting
And alternately. Therefore, each suitable extraction range
Can be selected, enabling more accurate extraction of white areas.
You. Further, in the present invention, based on the correlation between the change in the degree of saturation and the change in the luminance, the condition for the luminance signal and the condition for the chrominance signal are shrunk / expanded in the setting of the determination conditions for the white portion. it can. Therefore, when it is considered that only a portion having a relatively high saturation is considered to be white, the white portion extraction range in which the threshold value of the brightness regarded as a white portion is also high, and conversely, when the brightness is considered to be white to a relatively low brightness, the saturation level is determined. The white portion extraction range assuming that the threshold value is also low is used,
These are alternately switched. Therefore, it is possible to remove a portion having an apparently low degree of saturation due to a factor such as a low reflectance despite a large color shift amount.

When estimating the photographing environment using information such as the illuminance, for example, if it is determined that the luminous intensity is a certain level or more, it is determined that the outdoor photographing is performed. The environment is estimated in a form in which a coefficient corresponding to the illuminance value is added, and the result is output. Correspondingly, when shifting from a white balance control characteristic adapted to a specific shooting environment to a white balance control characteristic adapted to another shooting environment, the white balance control characteristic gradually changes according to the change of the coefficient. . As a result, the change in the white balance control characteristic accompanying the result of the environment determination becomes gentle, and stable white balance control is performed even when the shooting environment changes.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing an embodiment of a white balance control apparatus according to the present invention, wherein 1 is an image sensor, 2 is a color separation circuit, 3a and 3b are variable gain amplifier circuits, 4 is a color difference signal generation circuit, Is an arithmetic circuit, 6 is a white portion extraction circuit, 7
Is a white balance setting unit, 8 is a control unit, 9 is a subtraction circuit, 10 is an addition circuit, 11 is a gate signal generation circuit, 1
2, 13 are gate circuits, 14, 15 are integration circuits,
Reference numeral 17 denotes a comparison amplifier circuit, and reference numeral 18 denotes a white balance tracking circuit (hereinafter, referred to as a WB tracking circuit).

In FIG. 1, a color separation circuit 2 includes an image pickup device 1.
, The primary color signals G, R, and B are generated for each of the red (R), blue (B), and green (G) colors. Of these primary color signals, primary color signals R and B are variable gain amplifier circuits 3a and 3a, respectively.
After being amplified by 3b, the signal is supplied to the color difference signal generation circuit 4 together with the primary color signal G to be supplied to two color difference signals (RY, BY).
And a luminance signal Y are generated. The luminance signal Y and the color difference signals (RY, BY) are supplied to a processing circuit (not shown) for generating a color video signal, and are also supplied to a white balance control system described below. .

The white balance control system includes an arithmetic circuit 5, a white portion extraction circuit 6, a white balance setting unit 7, and a control unit 8, and includes a luminance signal Y and color difference signals (RY, BY). ) To detect the white portion in the photographing screen of the imaging device 1 and generate the gain control signals Sa and Sb for adjusting the white balance to generate the variable gain amplifier 3
a and 3b are controlled.

That is, the color difference signals (RY, BY) output from the color difference signal generating circuit 4 are supplied to an arithmetic circuit 5,
The subtraction circuit 9 and the addition circuit 10 perform subtraction processing and addition processing at a predetermined ratio (here, 1: 1), and
The orthogonal (RY) axes as shown in FIG.
A saturation detection signal (R−R) in the R (red) ← → B (blue) direction on a color difference plane expressed as a coordinate system of the (BY) axis.
B) is also Mg (magenta) in the addition circuit 10.
← → G (green) direction saturation detection signal (R + B−2Y) is generated. These saturation detection signals (RB, R + B-
2Y) are supplied to the white portion extraction circuit 6, respectively.

The white portion extraction circuit 6 is supplied with the saturation detection signals (RB, R + B-2Y) generated by the arithmetic circuit 5 and the luminance signal Y output from the color difference signal generation circuit 4, and receives a gate signal. , And a saturation detection signal (R−R) output from the subtraction circuit 9 of the arithmetic circuit 5 by the gate signal generated by the gate signal generation circuit 11.
B), and a saturation detection signal (R + B−) output from the addition circuit 9 of the arithmetic circuit 5 by the gate signal similarly generated by the gate signal generation circuit 11.
2Y).

The gate signal generation circuit 11 detects a low chroma portion (white portion) of the photographing subject of the image pickup device 1 using these chroma detection signals (RB, R + B-2Y).
Using the luminance signal Y, a high luminance portion of the photographing subject is detected. That is, the gate signal generation circuit 11 detects a high-luminance white portion of the photographic subject of the image sensor 1, and generates a gate signal representing this portion. The gate circuit 12 outputs a saturation detection signal (R−R) output from the subtraction circuit 9 of the arithmetic circuit 5.
B), the portion of the period of the gate signal is extracted, and the gate circuit 13 extracts the portion of the saturation detection signal (R + B-2Y) output from the addition circuit 10 of the arithmetic circuit 5 during the period of the gate signal. Is extracted. Therefore, the saturation detection signal (RB) output from the gate circuit 12 and the gate circuit 13
The saturation detection signal (R + B-2Y) output from is a saturation detection signal in a high-luminance white portion of the photographic subject of the image sensor 1.

The saturation detection signal (RB) output from the gate circuit 12 and the saturation detection signal (R + B-2Y) output from the gate circuit 13 are supplied to the white balance setting unit 7. In the white balance setting unit 7, the saturation detection signal (R-B) is integrated by the integration circuit 14 and averaged over one screen or several screens, and corresponds to a reference point of white balance control by the comparison amplification circuit 16. And compared with the reference voltage. Saturation detection signal (R + B-
2Y), the same processing is performed by the integration circuit 15 and the comparison amplification circuit 17. The WB tracking circuit 18 adds and subtracts the output signals of the comparison amplification circuits 16 and 17 at a predetermined ratio, for example, so that the high-luminance white portion of the photographic subject of the imaging device 1 is set as true white on the reproduction screen. It generates gain control signals Sa and Sb for setting the gains of the variable gain amplifier circuits 3a and 3b to be displayed.

By the way, on the color difference plane shown in FIG.
The relationship between the (RB) axis and the (R + B-2Y) axis is as shown, and the locus of a color temperature change (color change of natural light) according to blackbody radiation is shown as a dashed line in the figure. According to this, from the signal component in the (RB) axis direction (that is, the saturation detection signal (RB)), a true white color (white on the screen, and (RY) axis and (B
−Y) axis, the deviation from the (R + B−2Y) axis direction signal component (that is, the saturation detection signal (R + B−2)
From Y)), the deviation from true white due to a cause other than the above color temperature change can be known.

The above-described processing of the white portion extraction circuit 6 extracts a region surrounded by a rectangular frame including a locus of a color temperature change (color change of natural light) according to black body radiation on the color difference plane shown in FIG. Things. Hereinafter, this region is referred to as a white portion extraction range. From the detection result of the white portion extraction circuit 6, the white balance setting unit 7 determines that the high brightness white portion of the photographic subject of the image sensor 1 is on the (RY) axis in FIG.
-Y) to be displayed as a true white color represented by the intersection with the axis. In the white portion extraction range, a reference voltage (threshold) indicating the boundary of the white portion extraction range in FIG. 2 is set for each of the saturation detection signal (RB) and the saturation detection signal (R + B-2Y). It can be extracted by using a comparison circuit.

By the way, if only a color temperature change (color change of natural light) in accordance with blackbody radiation is to be detected, then-(R +
B-2Y) It is not necessary to detect the area in the axial direction. Detecting the area in the-(R + B-2Y) axis direction as described above is as follows.
This is to detect deviation from white due to artificial illumination. In the present embodiment, such different areas are alternately switched and set by the control unit 8, and the white portion of the photographing subject is extracted by either natural light or artificial illumination light.

As artificial lighting which is used relatively frequently, a fluorescent lamp can be cited. Generally, the color quality of a fluorescent lamp is on the green (G) side (almost-(R + B-2Y)) from the blackbody radiation locus described above.
(Axial direction). Therefore, in order to detect a change in color temperature of a fluorescent lamp or the like, a white portion extraction range including a region in the-(R + B-2Y) axis direction is set. However, the color temperature of commercially available fluorescent lamps is almost 4000 K (some types are 3000 K to 6000 K), and the range of white change is narrower than that of natural light.
For this reason, in the white portion extraction circuit 7, as shown in FIG.
On the green (G) side, a narrower (limited to lower saturation) white portion extraction range is set. By setting the white portion extraction range, it is possible to detect and correct a white shift due to a color temperature change in natural light and a white shift due to artificial illumination.

In the above description, the white portion extraction circuit 6 detects the white shift due to the change in color temperature with natural light and the white shift under artificial illumination separately. Considered white portion extraction can also be performed. Here, as for the luminance, higher luminance (for example, 8
0 IRE or more) and extraction with some redundancy (for example, 60 IRE or more). The saturation setting is set when the luminance is set higher according to the above-described saturation and luminance relativity. When the luminance is set low, the saturation setting is narrowed.

As described above, in addition to the detection of white shift caused by natural light or artificial lighting, the detection of white shift in accordance with the relativity between saturation and luminance can be performed to obtain a green shift (mainly for fluorescent lamps). , −
(R + B-2Y) axis direction) and magenta shift (mainly for natural light, + (R + B-2Y) axis direction) are combined with two-stage switching of luminance and saturation. Four types of white portion extraction ranges such as 3 are set. Here, FIGS. 3A and 3A show a white portion extraction range with natural light having a higher luminance (for example, 80 IRE or more), and FIGS. 3B and 3B show artificial regions with a higher luminance. FIGS. 3 (C) and 3 (c) show white part extraction ranges with natural light when there is some redundancy (for example, 60 IRE or more). FIGS. 3 (D) and 3 (d) show white part extraction ranges with natural light. This is a white portion extraction range with artificial light when a little redundancy is given.

The four kinds of white part extraction ranges are, for example, 1
The screen is sequentially switched and set repeatedly. The switching is performed by the control unit 8 in FIG. 1, for example, by the above-described saturation detection signal (RB) and the saturation detection signal (R + B−2).
This is performed by switching the reference voltage of the comparison circuit used for each Y). According to this switching, the white portion extraction range as shown in FIG. 4 is equivalently set, and both the white portion extraction for natural light and the white portion extraction for fluorescent lamps Both white portion extraction for white and white portion extraction for gray are possible. If this switching is performed one screen at a time, the integration circuits 14 and 15 in FIG. 1 average the saturation detection signals (RB) and (R + B-2Y) over four screens or more.

As described above, the extraction of the white portion for natural light and the extraction of the white portion for fluorescent lamps are performed separately. Since the part extraction condition can be set separately, a suitable extraction range can be selected for each part, and more accurate white part extraction can be performed.

FIG. 5 is a block diagram showing another embodiment of the white balance control apparatus according to the present invention. Reference numeral 19 denotes a photographing environment estimating section, and portions corresponding to those in FIG. Description is omitted.

In this embodiment, the whole or part of the white portion extraction range obtained as in the embodiment shown in FIG. 1 is changed in accordance with the photographing environment. The environment estimating unit 19 estimates from the information such as the aperture, the shutter speed, the illuminance detectable by the gain of the AGC circuit, the subject distance detectable by the focus adjustment device, and the date and time detectable by the clock device.

FIG. 6 shows an example in which there are three types of photographing environments: a specific photographing environment of outdoors (clear weather), indoors (night, no external light), and unknown (cloudy weather, near daylight windows, etc.). It is determined that the shooting environment is outdoor and indoor, respectively, by the outdoor determination rate (the determination rate is also referred to as an environmental coefficient) 10
The determination rate is 0%, the indoor determination rate is 100%, and the determination rate when the shooting environment is outdoor or indoors is unknown at all. Then, the more it is certain that the shooting environment is outdoor, the closer the outdoor determination rate is to 100%, and the more certain that the shooting environment is indoors, the closer the indoor determination rate is to 100%.

In the photographing environment estimating section 19, for example, a threshold value defining the specific photographing environment is set for each of the above information, and the unknown photographing environment is set according to the degree of the unknown. The range is also determined by the threshold. Then, the above-described confirmation rate is assigned to each specific shooting environment and each range set to unknown. Then, by comparing the detected information with a threshold, the above-described shooting environment and range are estimated, and a confirmation rate according to the estimation result is output.

Here, the white portion extraction range obtained by the white portion extraction circuit 6 in the same manner as in the embodiment shown in FIG. 1 corresponds to the white portion shown in FIGS. If the extraction range and the white portion extraction range shown in FIGS. 3B and 3B are switched, the shooting environment is unknown and the confirmation rate is 0%.
, The two white extraction ranges (25
(About 00 to 8000 ° K). As the outdoor confirmation rate increases, the white portion extraction range shown in FIGS. 3B and 3B is narrowed around the RB axis and the Mg-G axis.
(A) and (a) also narrow the direction of the RB axis in the white portion extraction range, and when the shooting environment is outdoor and this is determined (the outdoor determination rate is 100%), only natural light is used. FIG. 3 limited to about 5000-7000 ° K
The white balance is controlled only for the white portion extraction range shown in (A) and (a). Further, as the room confirmation rate increases, the area in the B-axis direction between the white portion extraction range shown in FIGS. 3B and 3B and the white portion extraction range shown in FIGS. 3A and 3A. When the shooting environment is indoors and this is confirmed (the indoor confirmation rate is 100%),
Natural light (including incandescent light) and fluorescent light.
The range is limited to about 5000 ° K and excludes the region in the B-axis direction, and the white balance is controlled by this.
As described above, when the shooting environment is unknown, the white balance is controlled for the entire range (about 2500 to 8000 ° K) including the outdoors and indoors. The limitation of the white extraction range is achieved by changing the setting range for the white portion extraction circuit 6 and the gain control signals Sa,
This is done by setting the upper and lower limits of Sb.

Therefore, for example, when the illuminance for determining that the shooting environment is outdoor is 10,000 lux, and the illuminance is 9000 lux,
In Lux, it is not determined that the camera is outdoors, but it is considered that the possibility of the shooting environment being outdoors is high because it is sufficiently bright. Therefore, the shooting environment estimation unit 19 determines at this time that it is unknown that it is close to the outdoors. Judge and output a high outdoor confirmation rate. Accordingly, the white portion extraction circuit 6 and the white balance setting unit 7 receive the output of the photographing environment estimation unit 19 and
As described above, the white extraction range is set from the setting at the time of unknownness to the setting at the time of outdoor determination by the determination rate.

It should be noted that here, as the shooting environment, an outdoor environment,
The case where the room is unknown is described as an example. However, the present invention is not limited to these cases, and a night view, a stage, or the like can be used as the shooting environment.

As described above, in this embodiment, the white balance control adapted to the photographing environment is performed, and the white balance control characteristic gradually follows the change of the photographing environment. If it is not possible to determine the white balance control, the white balance control characteristic can be set to an intermediate value, so that there is no sudden change in the characteristic and the white balance control is remarkably stabilized.

In the above embodiment, the white extraction range is set using the color difference signal. However, the white extraction range may be set using the primary color signal.

[0042]

As described above, according to the present invention,
Irrespective of the type of light source, more faithful white portion extraction is possible, and good white balance control can be realized , and highly accurate white balance control can be realized.
Can be.

Further, according to the present invention, white balance control suitable for the shooting environment is performed for each shooting environment, so that erroneous operations are reduced, and even when the shooting environment is uncertain, shooting is considered to be close. Since the characteristic becomes an intermediate characteristic close to the characteristic with respect to the environment, the control characteristic of the white balance also changes gently according to the change of the photographing environment, and stable white balance control is performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of a white balance control device according to the present invention.

FIG. 2 is a diagram illustrating a color difference plane representing a color temperature change of illumination.

FIG. 3 is a diagram showing an example of a white extraction range according to a light source in the embodiment shown in FIG. 1;

FIG. 4 is a diagram showing an example of a comprehensive white extraction range in the embodiment shown in FIG. 1;

FIG. 5 is a block diagram showing another embodiment of the white balance control device according to the present invention.

FIG. 6 is a diagram illustrating the principle of the embodiment shown in FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Image sensor 2 Color separation circuit 3a, 3b Variable gain amplifier circuit 4 Color difference signal generation circuit 5 Operation circuit 6 White part extraction circuit 7 White balance setting part 8 Control part 9 Subtraction circuit 10 Addition circuit 11 Gate signal generation circuit 12, 13 Gate Circuits 14, 15 Integrating circuits 16, 17 Comparative amplification circuits 18 White balance tracking circuits 19 Photographing environment estimation circuits

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-18991 (JP, A) JP-A-63-79491 (JP, A) JP-A-64-60088 (JP, A) JP-A 64-64 60089 (JP, A) JP-A-1-256890 (JP, A) JP-A-2-94790 (JP, A) JP-A-3-184491 (JP, A) JP-A-3-211988 (JP, A) JP-A-4-79692 (JP, A) JP-A-5-130636 (JP, A) JP-A-2-98561 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 9/73 H04N 9/04

Claims (7)

(57) [Claims] White portion extracting means for detecting as claimed in claim 1] IMAGING signal representative of the white portion of the set of signals captured object in the white portion extracting range of the generated color difference signals from the output signal of the element, By controlling the white portion extraction means, the color difference plane
Set and switch between different areas sequentially at predetermined intervals
The white part extraction range is set in the white part extraction means.
And control means for detecting the white balance deviation from a signal representative of the white portion detected by the white color portion extraction unit, according to the detection result
And amplify at least two of the color signals.
White balance control apparatus characterized by comprising a white balance setting means for generating a signal for controlling the gain of the variable gain amplifying means that. 2. The method according to claim 1, wherein the white portion extraction means outputs a color difference signal RY, BY before the color difference signal.
The signal components within the white extraction range are converted to white
The control means detects a signal representing a blackbody radiation locus on a color difference plane.
On the color difference plane on the green side of the first area.
And the range in the RB axis direction is closer to the RB direction in the first region.
A second area narrower than the range of the
The white balance control device is characterized in that the white portion extraction range is set by alternately setting the white portion extraction range . 3. The control device according to claim 1, wherein the control means performs white extraction at high luminance.
Widen the saturation of the area to extract white at low brightness
A white balance control device , wherein the saturation of the area is reduced . 4. The apparatus according to claim 1, wherein the control means includes a first color-difference plane including a black-body radiation locus.
On the green side of the first area on the color difference plane.
The second region offset and the first region on the color difference plane.
And the range in the luminance direction is smaller than that of the first region.
A third region, which is also wider than the second region on the color difference plane.
Also has a narrower range and a range in the luminance direction than the second region .
A wide fourth area is sequentially switched every predetermined period.
And setting the white portion extraction range . 5. The apparatus according to claim 1 , wherein said control means sets switching of said plurality of different areas.
Is performed for each screen, and the white balance setting unit includes the white portion extracting unit.
A signal representing the white portion extracted in the plurality of regions
Averaged over more than the number of screens equal to the number of
A white balance control device for detecting a white balance deviation . 6. The image pickup device according to claim 1 , wherein the image pickup device is based on a plurality of specific photographing environments set in advance.
The shooting environment of the camera, and calculate the environmental coefficient according to the estimation result.
Generate and extract the white portion according to the environmental coefficient
White balance system by white balance setting means
A white balance control device comprising a photographing environment estimating means for changing a follow-up range . 7. The image capturing device according to claim 6, wherein the image capturing environment of the image sensor is one of the plurality of specific image capturing environments.
As the environmental coefficient estimated to be
The white portion extraction range and the white balance setting means
The tracking range of the white balance control
Limited according to the shooting environment and the environmental coefficient
A white balance control device, characterized in that: