JPH0865689A - White balance controller - Google Patents

Abstract

PURPOSE: To prevent white balance from being erroneously set in a manual control mode concerning the white balance controller for an image signal. CONSTITUTION: Concerning the white balance controller provided with a color measuring means 21 for measuring the color of peripheral light, control value calculating means 22 for calculating the control value of white balance decided in advance corresponding to the measured color value of that color measuring means 21, manual setting means 23 for manually setting the control value of white balance, switching means 24 for manually selecting either the control value due to the control value calculating means 22 or the control value due to the manual setting means 23, and color ratio control means 25 for controlling the ratio of the stimulated values of image signals fetched from the outside corresponding to the control value selected by that switching means 24, this device is equipped with a comparing means 26a for comparing the control value due to the control value calculating means 22 with the control value due to the manual setting means 23 and an alarming means 26b for reporting the compared result of that comparing means to an operator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a white balance adjusting device for adjusting the ratio of stimulus values of an image signal,
The present invention relates to a white balance adjusting device capable of manually setting an adjustment value.

[0002]

2. Description of the Related Art In general, the human eye adapts to changes in the color temperature of ambient light and accurately senses the unique color of a subject.

On the other hand, in an image pickup device such as a video camera or an electronic still camera, the color of an output image signal changes according to the change in the color temperature of ambient light. Therefore, a white balance adjusting device that adjusts the color of an image signal according to the color temperature of ambient light has been conventionally known.

FIG. 7 is a diagram showing an electronic still camera to which this type of white balance adjusting device is applied. In the figure, an R light receiving element 2a, a G light receiving element 2b, and a B light receiving element 2c are arranged in a light receiving window 1, and these light receiving elements 2a are arranged.
The output terminals of ~ c are connected to the subtraction circuits 4a and 4b via the logarithmic compression circuit 3.

The output terminals of the subtraction circuits 4a and 4b are connected to a current-voltage conversion circuit 6 via an expansion circuit 5, and the output terminal of the current-voltage conversion circuit 6 is connected via an A / D conversion section 7. It is connected to the control unit 8.

A release button 8a, an adjustment mode switch 9, manual adjustment switches 10a to 10d, and memory circuits 11 and 12 for recording table data are connected to the control unit 8.

On the other hand, a diaphragm 16 is arranged on the optical axis of the taking lens 15 of the camera, and the imaging plane of the taking lens 15 has
An image pickup unit 17 including a CCD element is arranged. Of the output terminals of the image pickup unit 17, the signal (G signal) corresponding to the green stimulus value is connected to the signal processing unit 19, and the signals (R signal, B signal) corresponding to the red and blue stimulus values are
Variable gain amplifier 18 whose gain is controlled by the control unit 8
The signal processing unit 19 is connected via a and 18b, respectively. The signal processing unit 19 is connected to the recording unit 20.

In the electronic still camera having such a structure,
The operator operates the adjustment mode switch 9 to select the white balance manual adjustment mode or the automatic adjustment mode.

In the manual adjustment mode, the operator operates the manual adjustment switches 10a to 10d to set the white balance adjustment value. For example, the manual adjustment switch 10a-
“D” indicates “clear” or “cloudy” indicating ambient light with different color temperatures.
The types of "fluorescent lamp" and "bulb" are displayed, and the operator selects one from these.

The control section 8 takes in the states of the manual switches 10a to 10d set in this way and refers to the table data recorded in advance in the memory circuit 11 to obtain the manual adjustment value.

In the automatic adjustment mode, first, the light receiving elements 2a to 2c photoelectrically convert the ambient light incident from the light receiving window 1 to generate a red component (Rb), a green component (Gb) and a blue component of the ambient light. The signal (Bb) is output.

In the logarithmic compression circuit 3, these signals are logarithmically compressed to obtain logarithmic values (log Rb) and (log G of color components).
b), and outputs a signal corresponding to (log Bb). Further, these signals are mutually subtracted via subtraction circuits 4a and 4b to obtain a logarithmic value (log Rb / G) of the ratio of color components.
b), a signal corresponding to (log Bb / Gb) is output.

The expansion circuit 5 performs inverse logarithmic conversion by expanding these signals to obtain a color component ratio (Rb / Gb),
A signal corresponding to (Bb / Gb) is output. The signal processed as described above is supplied to the current / voltage conversion circuit 6 and A /
It is captured by the control unit 8 via the D conversion unit 7. The control unit 8 refers to the table data pre-recorded in the memory circuit 12 based on the ratio of the captured color components to obtain the automatic adjustment value.

On the other hand, the light incident from the taking lens 15 is
An optical image is formed on the image pickup unit 17 through the diaphragm 16. The imaging unit 17 photoelectrically converts this optical image and outputs an RGB signal corresponding to the tristimulus value. These RGB signals are
The color ratio is biased due to the influence of the color temperature of ambient light.

The control unit 8 uses the manual adjustment value or the automatic adjustment value obtained as described above to output the variable gain amplifiers 18a and 18a.
The gain of the R and B signals is changed by setting the gain of b. Therefore, the white balance of the RGB signal is corrected, and an RGB signal that reproduces a proper hue is obtained.

It should be noted that R after the white balance is adjusted
In the signal processing unit 19, the GB signal is subjected to gamma correction for correcting the luminance characteristic of the cathode ray tube in advance on the imaging device side and knee correction for reproducing the luminance gradation of the high luminance portion.
After being subjected to digital processing such as image compression, it is recorded in the recording unit 20 including a memory card or the like.

Therefore, in the conventional white balance adjusting apparatus, it is possible to automatically adjust the white balance change due to the color temperature of the ambient light by selecting the automatic adjustment mode.

Further, when the manual adjustment mode is selected, the operator can freely adjust the white balance, so that it is possible to perform photographing, for example, by taking advantage of changes in ambient light such as sunset.

[0019]

However, in the conventional white balance adjusting device, in the manual adjustment mode, the operator often forgets to change the adjustment value or sets the adjustment value by mistake. there were.

For example, when an outdoor image is taken with the bulb light having a low color temperature being manually set, a bluish tint due to the influence of sunlight having a high color temperature and a person's flesh color are unnatural. There was a problem that it was reflected.

Therefore, it is an object of the present invention to provide a white balance adjusting device which can prevent erroneous setting of white balance in the manual adjusting mode.

[0022]

FIG. 1 is a block diagram corresponding to the first and second aspects of the present invention. According to the first aspect of the invention, the colorimetric means 21 for measuring the ambient light, and the adjustment value for calculating the predetermined white balance adjustment value corresponding to the colorimetric value by the colorimetric means 21. The calculation means 22, the manual setting means 23 for manually setting the white balance adjustment value, the switching means 24 for manually selecting the adjustment value by the adjustment value calculation means 22 and the adjustment value by the manual setting means 23, and the switching thereof. In the white balance adjusting apparatus including a color ratio adjusting unit 25 for adjusting the ratio of the stimulus values of the image signal fetched from the outside according to the adjustment value selected by the unit 24, the adjustment value calculating unit 2
The comparison means 26a for comparing the adjustment value by 2 and the adjustment value by the manual setting means 23, and the informing means 26b for informing the operator of the comparison result by the comparison means 26a.

According to a second aspect of the invention, in the white balance adjusting apparatus according to the first aspect, the comparing means 26a sets the manual setting means 23 for the adjustment value of the adjustment value calculating means 22.
Is determined to be outside the predetermined allowable range, and the notifying means 26b gives a warning if the adjustment value of the manual setting means 23 is outside the allowable range by the comparison of the comparing means 26a. .

FIG. 2 is a block diagram corresponding to the invention described in claim 3. According to a third aspect of the present invention, the colorimetric means 21 for colorimetry of ambient light, and the adjustment value calculation for calculating a predetermined white balance adjustment value corresponding to the colorimetric value by the colorimetric means 21. Means 22, manual setting means 23 for manually setting the adjustment value of the white balance, switching means 24 for manually selecting the adjustment value by the adjustment value calculating means 22 and the adjustment value by the manual setting means 23, and its switching means. In the white balance adjusting device provided with the color ratio adjusting means 25 for adjusting the ratio of the stimulus values of the image signal fetched from the outside according to the adjustment value selected by 24, the adjustment value of the adjustment value calculating means 22 On the other hand, the determination means 27 for determining whether or not the adjustment value of the manual setting means 23 is outside a predetermined allowable range, and the determination result of the determination means 27 are taken in to adjust the manual setting means 23. There if permissible range, characterized in that an adjustment value correcting means 28 for correcting the adjustment value to a value within the allowable range.

[0025]

In the white balance adjusting device according to the first aspect, the adjustment value calculating means 22 obtains the white balance adjustment value corresponding to the colorimetric value of the colorimetric means 21. On the other hand, the operator manually sets the white balance adjustment value by the manual setting means 23.

The comparison means 26a takes in these adjustment values and compares the difference and the magnitude relationship between the two, and the notification means 26b notifies the operator of the comparison result. Therefore, the operator can determine whether or not the manual setting of the adjustment value is appropriate based on the notified comparison result.

Based on this judgment, the operator can operate the switching means 24 to switch from the manually adjusted value to the adjusted value by the adjusted value calculating means 22. Further, based on this judgment, the operator can operate the manual setting means 23 to set a manual adjustment value again.

The color ratio adjusting means 25 can more correctly adjust the ratio of the stimulus values of the image signal according to the adjustment value thus selected. In the white balance adjusting device according to claim 2, the comparing means 26a compares the adjustment value calculated by the adjustment value calculating means 22 with the manual adjustment value,
If the difference between the two is outside the predetermined allowable range, the notification means 2
The warning is notified by 6b.

With such a warning, the operator can easily and accurately determine whether the manually set value is out of the allowable range. In the white balance adjusting device according to the third aspect, the determining unit 27 compares the adjustment value calculated by the adjustment value calculating unit 22 with the manual adjustment value, and determines whether the manual adjustment value is outside the allowable range. When it is determined that the manual adjustment value is outside the allowable range, the adjustment value correcting means 28 corrects the manual adjustment value to a value within the allowable range.

Therefore, even if the operator erroneously sets the manual adjustment value, it is corrected to a manual adjustment value within a predetermined allowable range, and the white balance can be adjusted accurately.

[0031]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 is a diagram showing an embodiment corresponding to claim 1.

In the figure, the R light receiving element 3 is provided in the light receiving window 31.
2a, G light receiving element 32b and B light receiving element 32c are arranged, and the output terminals of these light receiving elements 32a to 32c are connected to subtraction circuits 34a and 34b via a logarithmic compression circuit 33.

The output terminals of the subtraction circuits 34a and 34b are connected to the current-voltage conversion circuit 36 via the expansion circuit 35, and the output terminals of the current-voltage conversion circuit 36 are connected via the A / D conversion section 37. It is connected to the control unit 38.

The control section 38 includes a release button 38a,
Adjustment mode switch 39, manual adjustment switch 40a-
d, and a memory circuit 41 for recording table data,
42 is connected.

Further, the control section 8 has a display section 43a for displaying in the finder and a memory circuit 43 for recording table data for judging whether or not the difference between the adjustment values is within an allowable range.
b is connected.

On the other hand, a diaphragm 46 is arranged on the optical axis of the taking lens 45 of the camera, and the imaging plane of the taking lens 45 is
An image pickup unit 47 including a CCD element or the like is arranged. Among the output terminals of the image pickup unit 47, the signal (G signal) corresponding to the green stimulus value is connected to the signal processing unit 49, and the signals (R signal, B signal) corresponding to the red and blue stimulus values are Variable gain amplifier 48 whose gain is controlled by the control unit 38
It is connected to the signal processing unit 49 via a and 48b individually. The signal processing section 49 is connected to the recording section 50.

The function of the control unit 38 in this embodiment is the adjustment value calculating means 22 and the manual setting means 2 shown in FIG.
3, corresponding to the functions of the comparison means 26a and the switching means 24. FIG. 4 is a flow chart showing the operation of this embodiment.

The operation of this embodiment will be described below. When the release button 38a is pressed halfway (step S1), the control unit 38 changes the ratio of the color components of the incident light of the light receiving window 31 to A / D.
It is taken in through the conversion unit 37 (step S2).

The control unit 38 reads the automatic adjustment values of the R signal and the B signal from the memory circuit 42 in which the automatic adjustment values are recorded in advance as table data corresponding to the ratio of the color components (step S3).

The white balance adjustment mode is determined by the state of the adjustment mode switch 39 (step S4). If the manual adjustment mode
Manual adjustment switches 40a-d for selecting "cloudy" or the like
Of the R signal and the B signal according to the states of these switches.
Is read (step S5).

Next, the difference between the automatic adjustment value and the manual adjustment value for the R signal and the B signal is calculated, and the difference is displayed on the display section 43a in the finder by, for example, a numerical value or a graph (step S6). .

Further, table data recorded in the memory circuit 43b for these differences (for example, table data recording whether or not these differences are within an allowable range by subjectivity evaluation experiments by a plurality of subjects). For a difference outside the allowable range, refer to the display section 43a in the finder.
A warning is displayed on the screen with pictures and letters (step S
7).

In this state, the manually adjusted values of the R and B signals are set to the gains of the variable gain amplifiers 48a and 48b (step S8). On the other hand, in the automatic adjustment mode, the automatic adjustment values of the R signal and the B signal are set to the variable gain amplifier 48.
The gain is set to a and 48b (step S9).

After such processing, the release button 38a
When is pressed fully (step S10), the RGB signal subjected to white balance adjustment by the variable gain amplifiers 48a and 48b is transferred to the recording unit 50 via the signal processing unit 49.
(Step S11).

When the operator releases the release button 38a (step S10), the process returns to step S1. As described above, in the white balance adjusting device of the present embodiment,
Since the difference between the automatic adjustment value and the manual adjustment value is displayed, the operator can judge whether or not the setting of the manual adjustment value is appropriate.

Further, since a warning is displayed for a difference outside the allowable range, the operator can easily and accurately judge whether the setting of the manual adjustment value is appropriate.
In addition, if the operator determines that the manual adjustment value setting is not appropriate, stop shooting, change the manual adjustment value setting, or change the adjustment mode so that the appropriate white Balance adjustment can be performed.

Further, since the display section 43a displays these pieces of information in the finder, the operator can judge whether or not the setting of the manual adjustment value is appropriate while looking through the finder. You can

Next, another embodiment will be described. Figure 5
[Fig. 4] is a diagram showing an embodiment of claim 3; A feature of the configuration of the present embodiment is that the control unit 58 is connected to the correction switches 44a to 44c for setting the correction mode of the manual adjustment value. Further, the control unit 58 includes a release button 58a, an adjustment mode switch 39, manual adjustment switches 40a to 40d, a memory circuit 4
1, 42, 43b and the display unit 43a are connected.

In FIG. 5, the same components as those of FIG. 3 are designated by the same reference numerals and the description thereof will be omitted. Further, the function of the control unit 58 in this embodiment is as shown in FIG.
It corresponds to the functions of the adjustment value calculating means 22, the manual setting means 23, the switching means 24, the judging means 27 and the adjustment value correcting means 28 shown in FIG.

FIG. 6 is a flow chart showing the operation of this embodiment. The operation of this embodiment will be described below. Release button 58
When a is pressed halfway (step S1), the control unit 58
The colorimetric value of ambient light is taken in and the white balance automatic adjustment value is obtained (step S2).

If the adjustment mode switch 39 is set to the "manual adjustment mode" (step S
3) Obtain the manual adjustment value of the white balance selected by the manual adjustment switches 40a to 40d, and determine whether the difference between these automatic adjustment values and the manual adjustment value is outside the allowable range (step S4).

If the difference is within the permissible range (step S5), the manual adjustment value is set to the gain of the variable gain amplifiers 48a and 48b, and photographing is performed. On the other hand, if the difference is outside the allowable range (step S5), the control unit 58 causes the correction switch 4
The states of 4a to 4c are fetched.

When the correction switch 44a is in the conductive state, the white balance is adjusted by the manual adjustment value as it is, and the photographing is performed. When the correction switch 44b is in the conductive state, the white balance is adjusted by the automatic adjustment value and shooting is performed.

When the correction switch 44c is in the conductive state, the manual adjustment value is increased or decreased in the direction in which the difference is decreased, and the white balance is adjusted by the manual adjustment value corrected within the allowable range to perform photographing.

As described above, in the white balance adjusting apparatus of this embodiment, the manual adjustment value outside the allowable range is corrected, so that the accurate white balance adjustment can be performed.
Further, by setting the allowable range, it is possible to adjust the white balance according to the setting of the operator for the manual adjustment value within the allowable range.

Furthermore, the correction switches 44a to 44c are set to select three correction modes ("no correction" and "correction").
Since “change to automatic adjustment value”) can be selected, the manual adjustment value can be corrected according to the operator's intention.

In the above embodiment, the difference between the automatic adjustment value and the manual adjustment value is displayed by a numerical value or a graph, but the present invention is not limited to this, and a plurality of pictures or characters are sequentially displayed according to the size of the difference. You may display it.

Further, in the above-mentioned embodiment, the picture or the character is displayed as a warning when the difference is out of the allowable range. However, the present invention is not limited to this, and the value or the color for displaying the difference is changed to warn. It may be displayed or a voice warning may be given.

Further, in the above-described embodiment, the difference between the adjustment values of the R signal and the B signal is displayed, but a calculation for obtaining a single evaluation value from the two differences using a predetermined evaluation function. Means may be provided to make a notification based on such an evaluation value, or to determine whether or not it is within the allowable range. With such a configuration, it is not necessary to perform processing on a plurality of adjustment values, and the processing of the comparing means, the notifying means, the determining means, etc. can be simplified.

[0060]

As described above, in the white balance adjusting apparatus according to the first aspect of the present invention, since the result of comparison between the adjustment value of the adjustment value calculating means and the adjustment value of the manual setting means is notified, the operator manually sets it. It is possible to judge whether the adjustment value is an appropriate value.

When the operator determines that the manually adjusted value is not appropriate, the switching means can switch to the adjusted value by the adjusted value calculating means 22.
Furthermore, the operator can manually set the adjustment value again by operating the manual setting means 23.

Therefore, it is possible to prevent the operator from setting the adjustment value incorrectly. In the white balance adjusting device according to the second aspect, since the warning is issued when the difference between the adjustment values is out of the allowable range, the operator can easily and surely know that the manual adjustment value is incorrect. You can

Therefore, it is possible to reliably prevent the operator from making an incorrect setting of the adjustment value. In the white balance adjusting device according to the third aspect, when the difference between the adjustment values is outside the allowable range, the manually adjusted value is corrected to a value within the allowable range. Therefore, even in the manual adjustment mode, the adjustment value within the allowable range is adjusted. White balance can be adjusted.

Therefore, it is possible to surely prevent the operator from making an erroneous setting of the adjustment value and to adjust the white balance accurately. As described above, in the image pickup apparatus to which the white balance adjusting apparatus according to the present invention is applied, it is possible to prevent an erroneous manual setting of the white balance adjustment value, so that the accurate white balance adjustment can be performed.

[Brief description of drawings]

FIG. 1 is a block diagram corresponding to the first and second aspects of the invention.

FIG. 2 is a block diagram corresponding to the invention according to claim 3;

FIG. 3 is a diagram showing an embodiment corresponding to claims 1 and 2;

FIG. 4 is a flowchart showing the operation of the embodiments of claims 1 and 2;

FIG. 5 is a diagram showing an embodiment corresponding to claim 3;

FIG. 6 is a flowchart showing the operation of the embodiment of claim 3;

FIG. 7 is a diagram showing a conventional example.

[Explanation of symbols]

 21 Colorimetric Means 22 Adjustment Value Calculating Means 23 Manual Setting Means 24 Switching Means 25 Color Ratio Adjusting Means 26a Comparing Means 26b Notification Means 27 Judging Means 28 Adjusting Value Correcting Means 32a-c Light-Receiving Elements 33 Logarithmic Compression Circuits 34a-b Subtraction Circuits 35 Expansion circuit 37 A / D conversion unit 38,58 Control unit 39 Adjustment mode switch 40a-d Manual adjustment switch 41,42,43b Memory circuit 43a Display unit 48a-b Variable gain amplifier

Claims (3)

[Claims] 1. A color measuring device for measuring ambient light, an adjusting value calculating device for calculating a predetermined white balance adjusting value corresponding to a color measuring value by the color measuring device, and a white balance. The manual setting means for manually setting the adjustment value, the switching means for manually selecting the adjustment value by the adjustment value calculating means and the adjustment value by the manual setting means, and the switching value according to the adjustment value selected by the switching means. hand,
In a white balance adjusting device comprising: a color ratio adjusting means for adjusting a ratio of stimulus values of an image signal fetched from the outside, the adjustment value by the adjustment value calculating means is compared with the adjustment value by the manual setting means. A white balance adjusting device comprising: a comparing unit; and a notifying unit for notifying an operator of a comparison result by the comparing unit. 2. The white balance adjusting apparatus according to claim 1, wherein the comparing unit determines whether or not the adjustment value of the manual setting unit is outside a predetermined allowable range with respect to the adjustment value of the adjustment value calculating unit. Determines whether or not, the notification means captures the comparison result of the comparison means,
A white balance adjusting device, which issues a warning if the adjustment value of the manual setting means is outside the allowable range. 3. A color measuring unit for measuring the color of ambient light, an adjustment value calculating unit for calculating a predetermined white balance adjustment value corresponding to the color measuring value by the color measuring unit, and a white balance. The manual setting means for manually setting the adjustment value, the switching means for manually selecting the adjustment value by the adjustment value calculating means and the adjustment value by the manual setting means, and the switching value according to the adjustment value selected by the switching means. hand,
In a white balance adjusting device including: a color ratio adjusting unit that adjusts a ratio of stimulus values of an image signal taken from the outside, an adjustment value of the manual setting unit is different from an adjustment value of the adjustment value calculating unit. Judgment means for judging whether or not it is outside a predetermined allowable range, the judgment result of the judgment means is taken in, and if the adjustment value of the manual setting means is outside the allowable range, the adjustment value is set to a value within the allowable range. A white balance adjusting device comprising: an adjusting value correcting unit for correcting.