JP2000111983A - Image pickup device and its method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a white balance excellent by adapting to a photographing condition at the time of using a stroboscope. SOLUTION: When the brightness information of a subject is within a range X1, a white balance control signal is formed corresponding to the color temperature Ts of the stroboscope. When the operation mode of the stroboscope is an automatic light emitting mode, the white balance control signal is formed corresponding to color temperature along characteristic Tx where the color temperature is changed from the color temperature Ts of the stroboscope to the color temperature Ty of external light in ranges X2 and X3 where the brightness information is equal to or larger than a parameter A and smaller than a parameter C, and the white balance control signal is formed corresponding to the color temperature Ty of the external light in the range X4 equal to or larger than the parameter C. When the operation mode of the stroboscope is a forcible light emitting mode, the white balance control signal is formed corresponding to the color temperature Tz in the range equal to or larger than a parameter B.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to an image pickup apparatus and an image pickup method capable of improving a white balance when a strobe device is used, for example.

[0002]

2. Description of the Related Art Recently, a number of compact digital cameras, camera-integrated VTRs, and the like have been put into practical use due to the development of electronic imaging technology and miniaturization of electronic circuits. These imaging apparatuses are easy to use in terms of ease of image processing and easiness of reproduction processing, and are becoming popularly used in general with the spread of personal computers. At present, a widely used imaging device is equipped with a strobe so as to be able to cope with dark place shooting.

[0003] These image pickup apparatuses are usually provided with an auto white balance control for improving color reproducibility by automatically controlling the white portion of the image so as not to change according to the color temperature of the light source. At the time of flash emission, the white balance is adjusted to the color temperature of the flash.

[0004]

There are various photographing conditions in which a strobe light is used, and the strobe light may be affected by external light other than the strobe light, or a portion where the strobe light is not applied may occur. Therefore, if the white balance is fixedly adjusted according to the color temperature at the time of the flash emission, there is a problem that the white balance is shifted in a portion where external light having a color temperature different from that of the strobe light is strong and in a portion where the strobe light does not shine. Was.

Accordingly, an object of the present invention is to provide an image pickup apparatus and an image pickup method which prevent white balance deviation by adapting the white balance at the time of strobe emission to photographing conditions, and have good color reproducibility. .

[0006]

In order to solve the above-mentioned problems, the present invention is directed to an image pickup apparatus in which the levels of a plurality of color signals of a photographed image signal are controlled by a white balance control signal. An image pickup apparatus characterized in that when it is estimated that there is an influence of external light, a white balance at the time of flash emission is controlled along a color temperature change that changes from a color temperature of the strobe device to a color temperature of external light. . The invention according to claim 7 is an imaging method for controlling white balance in consideration of the influence of external light at the time of actual shooting.

According to a second aspect of the present invention, there is provided an image pickup means for outputting a photographed image signal, a white balance means to which the photographed image signal is supplied and the levels of a plurality of color signals being controlled by a white balance control signal, and a white balance means. Means for recording an image signal from a recording medium on a recording medium, operation means for instructing recording, a strobe device which synchronizes with the recording instruction by the operation means, and which always emits light when the forced light emission mode is selected, and brightness of the subject. Generates a white balance control signal corresponding to the color temperature of the strobe device in a range darker than the first parameter, and in a range where the brightness of the subject is higher than the first parameter and lower than the second parameter,
Generates a white balance control signal along with a color temperature change that changes from the color temperature of the strobe device to the color temperature of external light,
A white balance control signal generating means for generating a white balance control signal corresponding to a color temperature between the color temperature of the strobe device and the color temperature of the external light when the brightness of the subject is higher than the second parameter; An imaging apparatus characterized in that:

According to a third aspect of the present invention, there is provided an image pickup means for outputting a photographed image signal, a white balance means to which the photographed image signal is supplied and the levels of a plurality of color signals are controlled by a white balance control signal, and a white balance means. Means for recording an image signal from a recording medium on a recording medium, operation means for instructing recording, and a strobe which synchronizes with the recording instruction by the operation means and emits light only when external light is dark when an automatic light emission mode is selected. In a range where the brightness of the device and the subject is darker than the first parameter, a white balance control signal corresponding to the color temperature of the strobe device is generated, and the brightness of the subject is higher than the first parameter and higher than the third parameter. In the dark range, a white balance control signal is generated according to the color temperature change that changes from the color temperature of the strobe device to the color temperature of external light. Brightness of the subject in the bright range third parameter above, an imaging apparatus characterized by comprising a white balance control signal generating means for generating a white balance control signal corresponding to the color temperature of approximately ambient light.

According to a fourth aspect of the present invention, there is provided an image pickup means for outputting a photographed image signal, a white balance means to which the photographed image signal is supplied and the levels of a plurality of color signals being controlled by a white balance control signal, and a white balance means. Means for recording an image signal from a recording medium on a recording medium, an operation means for instructing recording, a strobe device capable of emitting light in synchronization with a recording instruction by the operation means, and an operation mode of the strobe device in synchronization with the instruction. Forced flash mode that always fires,
Selecting means for selecting an automatic light emission mode in which light is emitted in synchronization with an instruction only when external light is dark; and in a forced light emission mode, the color temperature of the strobe device is set in a range where the brightness of the subject is darker than the first parameter. A corresponding white balance control signal is generated, and in a range where the brightness of the subject is higher than the first parameter and darker than the second parameter, along with the color temperature change from the color temperature of the strobe device to the color temperature of the external light. To generate a white balance control signal, and in a range where the brightness of the subject is brighter than the second parameter,
A white balance control signal corresponding to the color temperature between the color temperature of the strobe device and the color temperature of the external light is generated. In the automatic light emission mode, when the brightness of the subject is darker than the first parameter, A white balance control signal corresponding to the color temperature is generated, and in a range where the brightness of the subject is higher than the first parameter and darker than the third parameter, the color temperature that changes from the color temperature of the strobe device to the color temperature of the external light. A white balance control signal generating means for generating a white balance control signal in accordance with the change and generating a white balance control signal substantially in accordance with the color temperature of the external light in a range where the brightness of the subject is higher than the third parameter; An imaging apparatus characterized in that:

According to the present invention, the influence of external light during flash emission is estimated from the brightness of the subject, and the white balance is controlled in accordance with the color temperature taking into account the influence of external light. Further, the control method of the white balance is changed according to whether the operation mode of the strobe is the forced light emission mode or the automatic light emission mode. As a result, the white balance can be favorably controlled according to the operation mode of the strobe.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment in which the present invention is applied to a digital camera will be described below with reference to the drawings. FIG. 1 shows an overall configuration of an embodiment of the present invention.
As shown in FIG. 1, the digital camera is a lens unit 1, C
CD (Charge Coupled Device) 2, sample hold,
AGC (Automatic Gain Control) and A / D converter 3, camera signal processor 4, memory controller 5, buffer memory 6, D / A converter 7, LCD (Liquid Cryst)
al Display) 8, DRAM (Dynamic Random Access Me)
mory) 9, interface unit 10, external recording medium 1
1, a CPU 12, an operation input unit 13, an encoder / decoder 15, a strobe device 21, and a nonvolatile memory 22.

The lens unit 1 has a zoom, focus and iris mechanism, a drive circuit thereof, and the like. The lens unit 1 and the CCD 2 constitute an imaging unit. Control information from the CPU 12 is supplied to the lens unit 1, and an automatic iris control operation and an automatic focus control operation are performed. Therefore, the iris mechanism is opened and closed based on the control information from the CPU 12, and the light amount of the subject image supplied via the lens is adjusted. A subject image having a predetermined level of light amount through the lens and the iris mechanism is incident on the CCD 2.

The CCD 2 has a timing generation circuit and the like (not shown), performs exposure for a predetermined time based on control information from the CPU 12, and converts a subject image supplied through a lens and an iris mechanism into a signal charge. Take in as. The signal charge output of CCD2 is sampled and held,
The signal is supplied to the AGC and A / D converter 3.

The output of CCD2 is sample hold, AG
The digital image signal is supplied to the C / A / D converter 3 and is formed by the sample-and-hold, AGC and A / D converter 3 so that a digital image signal of 10 bits per sample is formed. The sample hold, AGC and A / D conversion unit 3 includes a buffer circuit, a CDS (Correlated Double Sampling) circuit,
It is composed of a GC circuit, an A / D converter, etc., and forms a digital image signal.

The camera signal processing section 4 comprises a digital clamp circuit, a luminance signal processing circuit, a color signal processing circuit, a defect compensation circuit, an automatic iris control circuit, an automatic focus control circuit, a white balance adjustment circuit, and the like. In the camera signal processing unit 4, the digital imaging signal is converted to form a digital image signal in the form of a component signal including a luminance signal and a color difference signal, and the digital image signal is supplied to the memory controller 5. Further, a brightness signal level as brightness information of the subject is supplied from the camera signal processing unit 4 to the CPU 12. The brightness information means not only the level of the brightness signal but also the brightness of the subject estimated by using the light amount received by the CCD 2, the degree of opening of the iris, the shutter speed, the control voltage of the AGC, etc., alone or in combination. I do.

FIG. 2 shows an example of the configuration of the main part of the camera signal processing unit. The digital imaging signal from the sample hold, AGC and A / D converter 3 is supplied to an input terminal indicated by 41 in FIG. The digital imaging signal is supplied to the color signal processing circuit 4 via the input terminal 41.
2 and the luminance signal processing circuit 43.

The color signal processing circuit 42 demodulates the three primary color signals (RGB signals) from the digital image pickup signal. RGB demodulated in the color signal processing circuit 42
The signal is supplied to the white balance circuit 45,
It is supplied to the CPU 12 through the output terminal 46. A white balance control signal is supplied to a white balance circuit 45 via a terminal 47. The white balance control signal is generated by the CPU 12 using the RGB signals.
The RGB signals from the white balance circuit 45 are supplied to a matrix conversion circuit (not shown) via the output terminal 48, and a color difference signal is generated.

The luminance signal processing circuit 43 includes a contour correction circuit, a level detection circuit, and the like. A luminance signal from the luminance signal processing circuit 43 is extracted to an output terminal 49. Further, signal level information is formed in the luminance signal processing circuit 43, and the signal level information is output as the brightness information or a part of the brightness information through the output terminal 44 through the CP.
It is supplied to U12.

Each component signal of the digital image signal from the camera signal processing unit 4 is supplied to a memory controller 5. The display buffer memory 6 and the bus 14 of the CPU 12 are connected to the memory controller 5. The buffer memory 6 generates RGB signals by processing the component signals, and outputs the RGB signals to the D / A converter 7. An analog signal from the D / A converter 7 is supplied to the LCD 8. Further, the buffer memory 6 outputs the RGB signals at a timing corresponding to the display timing of the LCD 8.

Further, the DRAM 9 and the C
The PU 12, the encoder / decoder 15, the interface unit 10, and the nonvolatile memory 22 are connected.
The DRAM 9 includes the memory controller 5 or the CPU 12
Is controlled by the address and control information supplied from the PC. Therefore, the digital image signal supplied via the memory controller 5 when the shutter is pressed is temporarily written into the DRAM 9. Note that the written digital image signal is read as necessary and supplied to the encoder / decoder 15 and the like. Non-volatile memory 22
Stores color temperature information of the strobe device 21 and parameters of white balance control required for white balance control as described later. These pieces of information are read out and supplied to the CPU 12 for white balance control during flash photography.

The encoder / decoder 15 is, for example,
Image data is compressed (encoded) or decompressed (decoded) based on PEG (Joint Photographic Experts Group). In this process, the encoding / decoding process may be performed by the software process of the CPU 12.

The interface unit 10 is an interface between the external storage medium 11 and the CPU 12. As the external storage medium, a disk-shaped recording medium such as a floppy disk, a memory card, or the like can be used. Further, C
An operation signal from the operation input unit 13 is supplied to the PU 12. The operation input unit 13 includes a shutter button and other various switches operated by the photographer. Operation input unit 13
Detects an operation of a button, a switch, or the like, and sends the detected signal to the CPU 12 as an operation signal.

A flash device 21 is shown in FIG. The strobe device 21 includes a strobe, a strobe discharge circuit, a light emission amount control circuit, and the like.
It is configured to emit light in synchronization with pressing of a shutter button according to control information from the CPU 12. The operation input unit 13 is provided with a switch for setting a shooting mode when a strobe is used. That is, three types of the automatic flash, the forced flash, and the flash prohibition are related to the strobe device 21.
One mode can be set. The forced light emission mode is a mode in which the strobe light is emitted regardless of the brightness of the subject. The automatic light emission mode is a mode in which the strobe light is emitted only when the brightness of the subject is insufficient based on the above-described brightness information such as the signal level information from the camera signal processing unit 4. The flash prohibition mode is a mode in which the strobe is not fired.

The CPU 12 generates a white balance control signal and supplies it to the white balance circuit 45. The present invention can use various known white balance controls. As an example of white balance control, RGB signals detected as a white portion of an image pickup signal are integrated, and the ratio of the integrated value of the R signal and the integrated value of the G signal (R /
G), and the ratio (B /
G) in which the gain of the R signal and the gain of the B signal are controlled by the gain control amplifier provided in the white balance circuit 45 in consideration of the fact that G) and the black body radiation curve 51 shown in FIG. There is.

The black body radiation curve 51 is obtained by taking an image of a white object under a light source having a different color temperature, forming an integrated value of each color signal of the RGB signal at that time, and calculating the ratio of the integrated value (R /
G) and (B / G). As shown by the black body radiation curve 51, when the color temperature is high, B /
When G is larger than R / G, while the color temperature is low, B / G is smaller than R / G in the blackbody radiation curve 51.

The light of the strobe is bluish light, and its color temperature is very high, as indicated by 52 in FIG. 3, and is located at a point slightly deviated from the black body radiation curve 51.
Therefore, during flash emission, the gain of the B signal is reduced,
White balance control is performed to increase the gain of the R signal. The video light is 53
As shown by, the color temperature is slightly lower and 3200 K ° (Kelvin temperature). Therefore, when the video light is used, white balance control is performed so as to increase the gain of the G signal and decrease the gain of the R signal. CPU 12
Generates a white balance control signal for controlling the gain of the B signal and the R signal corresponding to the color temperature of the light source, and supplies the white balance control signal to the terminal 47 of the white balance circuit 45.

FIG. 4 shows a white balance control operation when a strobe light is used in the embodiment of the present invention.
This will be described with reference to FIG. The vertical axis in FIG. 4 indicates color temperature, and the horizontal axis indicates brightness information. As described above, in the CPU 12, a white balance control signal for the white balance circuit 45 is formed corresponding to the color temperature.

Four ranges X1, X2, X3, and X4 are set by first, second, and third parameters A, B, and C (A <B <C) related to the brightness information. When the brightness information is smaller than the first parameter A, that is, in the range X1 where the incident light is small, a white balance control signal is generated corresponding to the color temperature of the strobe device 21 indicated by Ts. Actually, since the strobe device 21 has a variation in color temperature, the color temperature is measured at the time of assembly, and the measurement result is stored in the nonvolatile memory 22.
The parameters A, B and C are set in advance and stored in the nonvolatile memory 22. In the range X1 smaller than the parameter A, the strobe light is dominant, and the influence of external light can be ignored. Therefore, the white balance is controlled according to the color temperature Ts of only the strobe light.

In the range X2 where the brightness is higher than the parameter A and smaller than the parameter B, the color temperature T
s to the color temperature Ty of external light
Control the white balance along x. That is, the color temperature on the color temperature change characteristic Tx is determined from the brightness information. Similarly, in the range X3 where the brightness is higher than the parameter B and smaller than the parameter C, the white balance is similarly controlled along the color temperature change characteristic Tx that changes from the color temperature Ts of the strobe device to the color temperature Ty of the external light. I do. Further, in the range X4 where the brightness is equal to or more than the parameter C, the white balance is controlled according to the color temperature Ty of the external light. That is, in the range X4, the same automatic white balance control is performed as in the shooting without using the flash.

The change characteristic Tx of the color temperature is represented by the color temperature T of the external light.
This is the case where y is lower than the color temperature Ts of the strobe.
On the contrary, the color temperature Ty 'of the external light is the color temperature Ts of the strobe.
If the relationship is higher, a color temperature change characteristic is obtained as shown by Tx ′ in FIG.

When the operation of the strobe device 21 is in the forced light emission mode, when the brightness information is brighter than the parameter B, the color temperature change characteristic of the strobe and the external light The white balance is controlled corresponding to a predetermined color temperature Tz between the color temperature Ty.
When the operation of the strobe device 21 is in the automatic light emission mode, the white balance is controlled along the color temperature change characteristic Tx shown by the solid line.

The parameter B is set in the forced light emission mode because a subject to be photographed must exist in a range where the strobe light is irradiated. Therefore, the white balance corresponding to the color temperature close to the color temperature of the strobe light is set. It is for controlling. The parameter C is set in the automatic light emission mode. When the light is bright, the external light is dominant even if the strobe is fired. This is for controlling the white balance.

The above-mentioned color temperature change characteristics Tx, Tx ′ are:
Even if the color temperature Ts of the strobe device 21 is measured and obtained in advance, the color temperature Ts differs depending on the color temperatures Ty and Ty ′ of the external light. The color temperatures Ty and Ty ′ of the external light at the time of shooting are obtained by white balance control, and the parameters A and
Since the values of B and C are preset values, Ts and Ty
Or the color temperature characteristic Tx or Tx ′ connecting to Ty ′ is
It can be determined by linear approximation.

For example, the ranges X2 and X3 defined by the parameters A and C are divided into N steps at equal intervals, and
By dividing the difference between s and Ty by N, the change in color temperature per step is determined. Then, the difference (the number of steps) between the brightness information at the time of shooting and the parameter A is obtained, the number of steps is multiplied by the change in color temperature per step, and the multiplication result is subtracted from Ts to obtain the brightness at the time of shooting. The color temperature corresponding to the information is obtained. The color temperature Tz corresponding to the parameter B is calculated similarly. In this case, the difference (the number of steps) between the brightness information at the time of shooting and the parameter C may be obtained, the number of steps may be multiplied by the change in color temperature per step, and the multiplication result may be added to Ty.

As shown in FIG. 4, the color temperature when the strobe is used is determined in consideration of the influence of external light, and the white balance is controlled in accordance with the determined color temperature. Compared to white balance control in which the temperature is fixed to Ts, white balance can be controlled corresponding to a color temperature that is close to actual. Therefore, the white balance of the captured image can be improved. Also, the operation mode of the strobe device 21 (forcible flash mode / auto flash mode)
, The white balance can be controlled, so that better white balance control can be achieved.

FIG. 5 shows a processing procedure of the CPU 12 when performing the above-described white balance control. First, in step S1, it is determined whether the operation mode of the strobe device 21 is the light emission inhibition mode. If the mode is the light emission prohibition mode, the process proceeds to step S6, where the process is performed with the current white balance control signal and the process ends. Step S
If it is determined in step 1 that the mode is not the light emission inhibition mode, it is determined in step S2 whether the brightness information is brighter than the parameter A, that is, whether the brightness information is in the range X1 in FIG.

The brightness information is smaller than the parameter A (range X
When it is determined as 1), the color temperature Ts information of the strobe light stored in the nonvolatile memory 22 is read, and a white balance control signal corresponding to the color temperature Ts is output. If it is determined that the brightness information is brighter than the parameter A, it is determined whether the operation mode of the strobe device 21 is set to the automatic light emission mode (step S3).

If it is determined in step S3 that the automatic light emission mode has been set, it is determined in step S4 whether the brightness information is equal to or greater than the parameter C, that is, whether the brightness information is within the range X4 in FIG. When the brightness information is determined to be equal to or more than the parameter C (range X4), in step S7, the current white balance control signal is output, and the process ends. If it is determined in step S4 that the brightness information is not more than the parameter C (range X2 or X3), in step S10,
The color temperature along the color temperature change characteristic Tx or Tx ′ is calculated by the above-described linear approximation, and a white balance control signal corresponding to the color temperature is output.

On the other hand, if it is determined in step S3 that the forced light emission mode is set, it is determined in step S5 whether the brightness information is equal to or larger than parameter B (range X3). If so, step S8
In, the brightness information is fixed to the parameter B. Then, in step S10, the color temperature Tz is calculated by the above-described linear approximation, and a white balance control signal corresponding to the color temperature Tz is calculated and output.

Although one embodiment in which the present invention is applied to a digital camera has been described, the present invention is also applied to another image pickup apparatus, for example, an image pickup apparatus which is a camera-integrated VTR and capable of taking a still image. be able to. Further, the present invention can be applied to an imaging device using a solid-state imaging device other than a CCD, for example, a MOS sensor.

[0041]

According to the present invention, white balance control when using a strobe can be performed according to the color temperature taking into account the influence of external light, so that the white balance can be controlled according to actual shooting conditions. can do. Further, according to the present invention, the manner of controlling the white balance is switched according to the operation mode (forcible light emission mode / automatic light emission mode) of the strobe device, so that better white balance control can be achieved.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an overall configuration of an embodiment in which the present invention is applied to a digital camera.

FIG. 2 is a block diagram illustrating a partial configuration of a camera signal processing unit according to the embodiment of the present invention.

FIG. 3 is a schematic diagram illustrating an example of white balance control.

FIG. 4 is a schematic diagram for explaining white balance control when a strobe light is used in one embodiment of the present invention.

FIG. 5 is a flowchart illustrating white balance control when a strobe light is used according to an embodiment of the present invention.

[Explanation of symbols]

2 ... CCD, 3 ... Sample hold, AGC and A / D converter, 4 ... Camera signal processor, 9 ...
・ DRAM, 11 ・ ・ ・ External storage medium, 12 ・ ・ ・ CP
U, 13: operation input unit, 21: strobe device,
22: Non-volatile memory, 45: White balance circuit

Continuation of the front page F term (reference) 2H002 AB02 AB04 CD11 GA33 JA07 2H053 AA00 AA01 AB02 AB03 BA71 DA03 5C065 BB02 BB07 BB08 BB41 CC02 CC03 DD02 EE06 FF02 GG11 GG12 GG15 GG18 GG27 GG30 GG32 5A066 GBA EA01 KE19 KE20 KG08 KM02 KM13 LA02

Claims (7)

[Claims] 1. An image pickup apparatus in which the levels of a plurality of color signals of a photographed image signal are controlled by a white balance control signal. An image pickup apparatus, wherein control is performed in accordance with a color temperature change that changes from a color temperature of the apparatus to a color temperature of external light. 2. An image pickup means for outputting a photographed image signal; a white balance means to which the photographed image signal is supplied, wherein the levels of a plurality of color signals are controlled by a white balance control signal; Means for recording a signal on a recording medium; operating means for instructing recording; a strobe device which emits light whenever a forced flash mode is selected in synchronization with the recording instruction by the operating means; In the darker range than the parameter of 1,
The white balance control signal corresponding to the color temperature of the strobe device is generated, and in a range where the brightness of the subject is higher than the first parameter and darker than the second parameter, the external light is shifted from the color temperature of the strobe device. The white balance control signal is generated in accordance with the color temperature change that changes to the color temperature, and in a range where the brightness of the subject is brighter than the second parameter, the color temperature of the strobe device and the color temperature of the external light are calculated. An imaging apparatus comprising: a white balance control signal generating unit configured to generate the white balance control signal according to a color temperature between the two. 3. An image pickup means for outputting a photographed image signal, a white balance means to which the photographed image signal is supplied and a level of a plurality of color signals controlled by a white balance control signal, and an image from the white balance means. Means for recording a signal on a recording medium; operation means for instructing recording; and a strobe device which synchronizes with the recording instruction by the operation means and which emits light only when external light is dark when an automatic light emission mode is selected. In the range where the brightness of the subject is darker than the first parameter,
The white balance control signal corresponding to the color temperature of the strobe device is generated, and in a range where the brightness of the subject is brighter than the first parameter and darker than the third parameter, the white light is controlled based on the color temperature of the strobe device. The white balance control signal is generated according to a color temperature change that changes to a color temperature, and in a range where the brightness of the subject is higher than the third parameter, the white balance control signal substantially corresponding to the color temperature of the external light An image pickup apparatus comprising: a white balance control signal generating unit that generates a white balance control signal. 4. An image pickup means for outputting a photographed image signal, a white balance means to which the photographed image signal is supplied and the levels of a plurality of color signals are controlled by a white balance control signal, and an image from the white balance means. Means for recording a signal on a recording medium; operating means for instructing recording; a flash device capable of emitting light in synchronization with a recording instruction by the operating means; and an operation mode of the flash device in synchronization with the instruction. Selection means for selecting between a forced light emission mode in which light is always emitted and an automatic light emission mode in which light is emitted in synchronization with the instruction only when the external light is dark; In the dark range, the white balance control signal corresponding to the color temperature of the strobe device is generated,
In a range where the brightness of the subject is higher than the first parameter and darker than the second parameter, the white balance control signal is generated along with a color temperature change from the color temperature of the strobe device to the color temperature of external light. If the brightness of the subject is higher than the second parameter, the white balance control signal corresponding to the color temperature between the color temperature of the strobe device and the color temperature of the external light is generated, and the automatic white balance control signal is generated. In the light emission mode, in a range where the brightness of the subject is darker than the first parameter, the white balance control signal corresponding to the color temperature of the strobe device is generated, and the brightness of the subject is brighter than the first parameter and In the range darker than the third parameter, the white color changes along with the color temperature change from the color temperature of the strobe device to the color temperature of the external light. A white balance control signal generating means for generating a light balance control signal and generating the white balance control signal substantially in accordance with the color temperature of the external light in a range where the brightness of the subject is higher than the third parameter. An imaging device characterized by the above-mentioned. 5. The imaging apparatus according to claim 1, wherein the color temperature of the strobe device is measured in advance, and the measured color temperature information is stored in a nonvolatile memory. . 6. The strobe device according to claim 1, wherein the color temperature on the color temperature change from the color temperature of the strobe device to the color temperature of the external light is the color temperature of the strobe device and the color temperature of the external light. An imaging apparatus characterized by being calculated by linear approximation using a color temperature and the first and third parameters. 7. An image pickup method in which the levels of a plurality of color signals of a photographed image signal are controlled by a white balance control signal. An imaging method, wherein control is performed in accordance with a color temperature change that changes from the color temperature of the device to the color temperature of external light.