JP3566845B2 - Imaging system - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
More specifically, the present invention relates to an imaging system having an AE and AWB control function and a function necessary for automatically performing AWB adjustment for correcting a characteristic variation between individual imaging devices.
[0002]
[Prior art]
2. Description of the Related Art As a conventional color image pickup apparatus, for example, there is one described in Japanese Patent Application Laid-Open No. 5-68257. Such a color imaging apparatus is a color imaging apparatus having a white balance adjustment circuit for adjusting a white balance by adjusting a gain of a predetermined channel of a color signal by a color imaging unit. And a filter driving means for arranging a specified color temperature filter of the filter member on the photographing optical axis, and selecting the color temperature filter of the color temperature conversion filter member of the filter member based on the photographed surface image, and then selecting the white balance. The white balance is adjusted by a white balance adjustment circuit by an adjustment circuit. This color imaging device includes an optical filter in the device.
[0003]
[Problems to be solved by the invention]
As described above, in the imaging apparatus, it is necessary to control the white balance in order to obtain a good color image. When the white balance is deviated, not only does the captured image appear to be tinted when a white object is photographed, but also the color reproducibility when a general object is photographed is deteriorated, and a good photographed image is obtained. Can not be.
[0004]
In addition, since an image pickup apparatus generally has characteristic variations among individuals such as a spectral sensitivity characteristic of a CCD, in order to obtain a good white balance, in order to correct the dispersion, an AWB initial gain value is set for each image pickup apparatus. And the AWB control limit gain value must be measured in advance.
[0005]
The present invention has been made in view of the above problems, and has as its object to provide an imaging system capable of automatically performing AWB adjustment for correcting variation in characteristics between individual imaging devices.
[0006]
[Means for solving the problem]
In order to solve the above-mentioned problem, an imaging system according to claim 1 converts an object into an electric signal via an optical system and outputs the signal as a color image signal, and an AWB evaluation value corresponding to the color image signal. AWB evaluation value output means for outputting an AE evaluation value corresponding to the color image signal, AE evaluation value output means for outputting the AWB evaluation value and the AE evaluation value to the outside, AWB control means for calculating an AWB control value for adjusting a white balance based on an AWB initial gain value and an AWB control limit gain value, AWB control setting means for setting the AWB control value, and adjusting an exposure amount AE control means for calculating a control value for performing the control, AE control value setting means for setting the calculated AE control value, and AW for setting whether or not to stop the AWB operation An operation mode setting means, and an external setting means for externally transmitting an AWB control value and an AE control value, wherein the AWB operation is stopped by the AWB operation mode setting means, and the color and brightness of the subject are changed by a color conversion optical filter or the like. Is changed, and the AWB initial gain value and the AWB control limit gain value are calculated with the exposure amount kept constant by AE.
[0007]
An imaging system according to a second aspect is the imaging system according to the first aspect, further comprising AE operation mode setting means for setting whether to stop the operation of the AE.
[0008]
In the imaging system according to a third aspect, in the imaging system according to the second aspect, the AE control value, the AWB control value, the AE operation mode, and the AWB operation mode are set from an input unit of the imaging apparatus. Things.
[0009]
In the imaging system according to a fourth aspect, in the imaging system according to the second aspect, the AE control value, the AWB control value, the AE operation mode, and the AWB operation mode are set from an external terminal device. is there.
[0010]
Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.
[0011]
[Summary of the Invention]
{Circle around (1)} In order to adjust a constant used for controlling the AWB (hereinafter referred to as adjustment), it is necessary to temporarily stop the function of the AWB. In addition, it is necessary to use several types of color conversion optical films for the adjustment. However, since these filters have different transmittances, the amount of light from the subject changes. Differences in the size and accuracy of Therefore, the imaging device needs to have a function of stopping the operation of the AWB while the operation of the AE is enabled. In order to realize the automatic adjustment system, it is necessary to be able to externally perform the setting as to whether or not the AWB operation is performed as described above and the operation of reading out the evaluation values of the AE and AWB control values.
[0012]
{Circle around (2)} In order to adjust the constants used for controlling the AWB (hereinafter referred to as “adjustment”), it is more accurate to set the data amount not to change for each data measurement under the same conditions. Can be calculated. In addition, it is necessary to use several types of color conversion optical filters for the adjustment, but since these filters have different transmittances, the amount of light from the subject changes when the AE and AWB operations are stopped. This causes a difference in the size and accuracy of the data (evaluation value) used for the adjustment. Therefore, it is necessary for the imaging apparatus to have a function of stopping the operation of the AE and the AWB and to be able to set the control values of the AE and the AWB even in the stopped state. Further, in order to realize the automatic adjustment system, it is necessary to be able to externally perform the setting of whether or not to perform the operation of the AWB and the AE as described above, the setting of the control value of the AE and the AWB, and the operation of reading the evaluation value. is there.
[0013]
{Circle around (3)} The input unit of the imaging apparatus has a function of setting each of an AE control value, an AWB control value, an AE operation mode, and an AWB operation mode, so that if only a standard subject is prepared, it is used for AWB control. It is possible to calculate and set the AWB initial gain value and the AWB control limit gain value, and to confirm whether the set values are correct.
[0014]
The present invention proposes an imaging system for realizing an automatic adjustment system for detecting an AWB constant, which automatically calculates and sets an AWB initial gain value and an AWB control limit gain value used for AWB control.
[0015]
FIG. 1 is a configuration diagram of an imaging system according to the present embodiment. In FIG. 1, reference numeral 100 denotes an imaging system. The imaging system 100 includes an imaging device 200 and an adjustment device 300 for the imaging device.
[0016]
The imaging device 200 includes a lens, a mechanical mechanism including an autofocus, a CCD 201, an A / D converter, variable gain amplifiers (amplifiers) 203r, 203g, 203b, a color difference conversion matrix circuit 204, and an AE / AWB evaluation value extraction circuit 205. , A control circuit 206, and a TimingSG (control signal generator) 209.
[0017]
The lens unit includes a mechanical mechanism including a lens, an autofocus (AF), an aperture, and a filter. A CCD (Charge Coupled Device) 201 converts an image input through a lens unit into an electric signal (analog image data) and outputs analog image data for each of R, G, and B. The A / D converter 202 converts RGB analog image data output from the CCD 201 into digital image data, and outputs the digital image data to a variable gain amplifier (amplifier) 203 at a subsequent stage.
[0018]
The variable gain amplifiers (amplifiers) 203r, 203g, and 203b amplify and output RGB digital image data input from the A / D converter 202 with the gain set by the control unit 206, respectively. The chrominance matrix conversion circuit 204 converts digital image data input from the variable gain amplifiers (amplifiers) 203r, 203g, and 203b into chrominance (Cb, Cr) and luminance (Y) and outputs them.
[0019]
The AE / AWB evaluation value extraction circuit 205 extracts three AWB evaluation values and one AE evaluation value for each of RGB generated from each of RGB of digital image data input from the variable gain amplifiers 203r, 203g, and 203b. Output to the control unit 203.
[0020]
The control unit 206 includes a microcomputer (not shown) including a CPU, a ROM, a RAM, and the like. The CPU uses the RAM as a work area according to a program stored in the ROM, and issues an instruction from the key operation unit 207, Controls the entire operation of the imaging apparatus according to an external operation instruction such as a remote controller (not shown) or a communication operation instruction by communication from an external terminal such as a personal computer (hereinafter, referred to as a “PC”) 301. Specifically, the control unit 206 controls an imaging operation, a white balance (AWB) operation, an AE operation, and the like.
[0021]
The key operation unit 207 is for giving an operation instruction of the imaging apparatus, and includes a release key for giving an instruction for photographing and buttons for making various other settings from outside. In the flash memory 208, initial data (including an AWB initial gain) and the like for controlling the imaging device are written. The timing SG (control signal generator) 209 generates a timing signal for capturing an electric signal from the CCD 201 and outputs the timing signal to the CCD 201 under the control of the control unit 206. The above-described imaging device 200 has an AE function and an AWB function.
[0022]
Next, a basic operation of the AWB control of the imaging apparatus 100 will be briefly described.
First, a subject image via a lens (not shown) is incident on the CCD 201. The CCD 201 converts the subject image into an electric signal (analog image data) and outputs R, C, and B analog image data. The variable gain amplifiers 203r and 203b amplify and output the digital image data of R and 8 respectively with the gain set by the control unit 206.
[0023]
The AE / AWB evaluation value output circuit 205 outputs to the control unit 206 three AWB evaluation values generated from the RGB luminance data of the digital image data input from the variable gain amplifiers 203r, 203g and 203b. The control unit 206 calculates gains to be set in the variable gain amplifiers 203r, 203g, and 203b based on the AWB evaluation value and the AWB initial gain value written to the flash memory 208 in the AWB adjustment described later, and The white balance is controlled by setting the calculated gain in the variable gain amplifiers 203r and 203b.
[0024]
In the above description, the gains to be controlled are R and B. However, the present invention is not limited to these, and the gain of at least two or more combinations of R, G and 8 may be controlled. .
[0025]
Next, the basic operation of the AE control of the imaging device 100 will be briefly described.
The AE / AWB evaluation value output circuit 205 generates one AE evaluation value from the RGB luminance data of the digital image data input from the variable gain amplifiers 203r, 203g and 203b, and outputs the AE evaluation value to the control unit 206. The control unit 206 controls the aperture of the lens unit and the shutter open time based on the AE evaluation value, and adjusts the exposure amount.
[0026]
As shown in FIG. 1, the adjustment device 300 of the imaging device includes a PC 301 that controls an adjustment operation of an AWB initial gain value and an AWB control limit gain value, and four types of color temperature filters 303a (W4 filters) having different color temperatures from each other. , 303b (C10 filter), 303c (C4 filter), and 303d (W18 filter), and a filter movement for arranging a designated color temperature filter of the filter member 303 on the photographing optical axis of the imaging apparatus 200. And a lighting source (not shown) for emitting a fixed amount of light.
[0027]
FIG. 2 is a diagram showing the configuration of the PC 301. As shown in FIG. 2, the PC 301 includes an input unit 400 for giving an operation instruction, a CPU 401 for controlling the entire computer device, a ROM 402 for storing various control programs and data for operating the CPU 401, and a work area of the CPU 401. And an I / F 404 for performing data communication. The control program includes, for example, a program for executing AWB adjustment and outputting an AWB gain value for each color temperature filter (each illumination condition) to the flash memory 208 of the imaging device 200. In the ROM 402, AE data corresponding to each color temperature filter 303a (W4 filter), 303b (C10 filter), and 303c (W18 filter) is written.
[0028]
The PC 301 controls the filter moving motor 302 to select one of the color temperature filters 303 a to 303 d of the filter member 303, arranges the selected one on the shooting optical axis of the imaging device 200, and shoots the image on the imaging device 200. And an AWB gain value and an AWB control limit gain at the designated color temperature filter based on each AWB evaluation value generated from each of the RGB luminance data output from the AE / AWB evaluation value extraction circuit 205. Calculate the value. The PC 301 performs the operation of calculating the AWB gain value for all the color temperature filters 303a to 303d, and writes the AWB gain value of each of the color temperature filters 303a to 303d to the flash memory 208 of the imaging device 200 via the control unit 206.
[0029]
The AWB gain value calculated using each of the color temperature filters is used as an initial gain value and a control limit gain value of AWB control. Next, the operation of AWB adjustment performed by the imaging system 100 (the imaging device 200 and the adjustment device 300 of the imaging device) will be described. The AWB adjustment is an adjustment for calculating an AWB initial gain value, an AWB control limit gain value, and an AWB control limit gain value used in the AWB control of the imaging apparatus 100. In this AWB adjustment, for example, a transmissive gray scale is set in the illumination source, and four color temperature filters 303a (W4 filter), 303b (C10 filter), By switching between 303c (C4 filter) and 303d (W18 filter), the illumination condition is changed and the AWB gain value for each color temperature filter is calculated.
[0030]
<Operation example 1>
An operation example 1 of the AWB adjustment will be described with reference to a flowchart of FIG. In this operation example 1, the color temperature filters 303a (W4 filter), 303b (C10 filter), 303c (C4 filter), and 303d (W18 filter) are switched while the AE function and the AWB function are stopped. Using a plurality of color temperature filters having different temperature characteristics, AE data to be used for exposure amount control corresponding to the selected color temperature filter is set and photographing is performed. In this photographing, AE / AWB evaluation value extraction An AWB gain corresponding to each color temperature filter is calculated based on each AWB evaluation value calculated from each RGB luminance data of the digital image data output from the circuit 205.
[0031]
In FIG. 5, first, when the power of the imaging device 200 and the adjustment device 300 (PC 301 and filter moving 302) of the imaging device is turned on, initial reduction of the imaging device 200 and the PC 301 is performed (steps S1, P1). In the imaging device 200, the recording / adjustment mode is set (step P2), and a display menu as shown in FIG. 3 is displayed on the display of the PC 301 (step S2).
Then, when AWB adjustment is selected from the display menu screen of the PC 301 (see FIG. 3) (step S3), a filter selection screen as shown in FIG. 4 is displayed, and a filter is selected from this selection screen. (Step S4). Then, the PC 301 controls the filter driving motor 302 to arrange the selected color temperature filter of the filter member 303 on the photographing optical axis of the imaging device 200 (Step S5).
[0032]
Subsequently, the PC 301 reads the command indicating the start of the AWB adjustment and the AE data corresponding to the selected color temperature filter from the ROM 402, and transmits them to the imaging device 206 (Step S6). Then, the value of the counter X is set to the initial value "0" (step S7). Upon receiving this command and the AE data corresponding to the selected color temperature filter (step P3), the control unit 206 of the imaging device 200 turns off the AE control function and the AWB control function (step P4), and converts the received AE data. The aperture value and the shutter release time calculated for the object are set in the lens unit, and shooting is performed (step P5).
[0033]
Here, the photographing operation will be briefly described. A subject image via a lens (not shown) is incident on the CCD 201, and the CCD 201 converts the subject image into an electric signal (analog image data), and outputs R, G, The analog image data of B is output. The variable gain amplifiers 203r, 203g, and 203b amplify and output the R and B digital image data with the gain set by the control unit 206, respectively.
[0034]
The AE / AWB evaluation value extraction circuit 205 includes luminance data R1 to Ro (n indicates the number of pixels) for each pixel of R, G, and B digital image data input from the variable gain amplifiers 203r, 203g, and 203b. The control unit 206 outputs three AWB evaluation values ΣR, ΣG, and ΣB as AWB evaluation values generated based on G1 to Gn and B1 to B1 and an AE evaluation value for luminance calculation to the control unit 206.
[0035]
When the control unit 206 receives the AWB evaluation values ΣR, ΣG, and ΣB (step S8), the PC 301 subsequently calculates ΣR / ΣG and ΣB / ΣG (step S9), and sets the value of the counter K to “1”. Is incremented (step S10).
[0036]
Subsequently, the CPU 207 determines whether or not ΣR / ΣG and ΣB / ΣG are within specified values (near 1) (step S11), and if ΣR / ΣG and ΣB / ΣG are within specified values. The R and G gains at this time are sent to the control unit 206 of the imaging device 200 as AWB gain values (step S12). When receiving the R and G AWB gain values, the control unit 206 of the imaging device 200 writes the R and G AWB gain values into the flash memory 208 (Step P7).
[0037]
On the other hand, if ＳR / ΣG and ΣB / ΣG are not within the specified values (near 1) in step S11, the process proceeds to step S13 to determine whether the value of the counter K, that is, the number of adjustments is larger than N than the specified number. Is determined, and if K> N, it is determined that the digital camera or the environmental condition is abnormal, and the fact is displayed on the display of the PC 301 to notify the operator (step S15).
[0038]
On the other hand, if K <N is not satisfied, the process shifts to step S14 to calculate R and G gains such that ΣR / ΣG and ΣB / ΣG are close to 1, and together with the calculated R and G gains, again. The fact that imaging should be performed is sent to the control unit 206 of the imaging device 200 (step S14). In response, the control unit 206 of the imaging device 200 sets the calculated R and G gains in the variable gain amplifiers 203r, 203g, and 203b to perform shooting (Step P4), and sends out the AWB evaluation value again (Step P4). Step P6).
[0039]
Then, after receiving 後 R, ΣG, and ス テ ッ プ B (step S8), the PC 301 calculates ΣR / ΣG, ΣB / ΣG (step S9), and increments the value of the counter K by “1” (step S10). , ΣR / ΣG and ΣB / ΣG are within specified values (near 1), and this process (steps S14, P5, P6, S8, S9, S10, S11, S1S) is repeated with the predetermined number N as a limit.
[0040]
The above processing (steps S4 to S14, steps P3 to P6) is performed for each of the color temperature filters 303a, 303b, 303c, and 303d, and the AWB gain under each illumination condition is written to the flash memory 208.
In the first operation example, AE data corresponding to the selected color temperature filter is transmitted from the PC 301, and the control unit 206 of the imaging device 200 determines the aperture value and the shutter release time calculated based on the AE data by using the lens unit. However, the configuration may be such that AE data is input from the key operation unit 207 of the imaging device 200 and the exposure amount of the imaging device 200 is controlled.
[0041]
According to the operation example 1, the color temperature filters 303a (W4 filter), 303b (C10 filter), 303c (C4 filter), and 303d (W18 filter) are switched while the AE function and the AWB function are stopped. Using a plurality of color temperature filters having different color temperature characteristics, exposure amount control is performed by AE data corresponding to the selected color temperature filter. In this case, the AE / AWB evaluation value extraction circuit 205 outputs an exposure value. Since the AWB gain value corresponding to each color temperature filter is calculated based on the evaluation value corresponding to each luminance data of the digital image data of R, G, and B, filters having different color temperature characteristics are used. When calculating the AWB gain values respectively, the amount of light from the subject can be kept constant, and there is little variation between individual imaging devices. It is possible calculate the high AWB gain value accuracy. As a result, the imaging device can properly reproduce colors even when the color temperature of the light source changes.
[0042]
Since all settings for the imaging device 200 can be made from an external terminal such as the PC 301, all adjustment work and work for checking the adjustment result can be automatically performed. This eliminates the need for human judgment, and thus makes it possible to make adjustments with small variations among individual imaging devices.
[0043]
In addition, since all settings for the imaging device 200 can be performed from the key operation unit 207 of the imaging device 200, even if a jig such as the adjustment device 300 of the imaging device is not prepared, the setting becomes standard with the imaging device 200. If only the subject is prepared, a simple adjustment work and a check work of the adjustment result can be performed.
[0044]
<Operation example 2>
Operation example 2 of the AWB adjustment will be described with reference to the flowchart of FIG.
[0045]
In the second operation example, while the operation of the AWB function is stopped and the AE function is operated, the color temperature filters are switched to use a plurality of color temperature filters having different color temperature characteristics. The AE / AWB evaluation value depiction circuit 205 outputs a digital image data output from the AE / AWB evaluation value depiction circuit 205 based on the evaluation values generated by the RGB luminance data. Calculate the corresponding AWB gain value.
[0046]
By operating the AE function, the adjustment can be performed with the exposure amount kept constant even if the color temperature filters are different.
[0047]
In FIG. 6, first, when the power of the imaging apparatus 200 and the adjustment apparatus 300 (PC 301 and filter moving 302) of the imaging apparatus is turned on, initialization processing of the imaging apparatus 200 and the PC 301 is performed (steps S11 and P11). In the imaging device 200, the recording / adjustment mode is set (step P12), and a display menu as shown in FIG. 3 is displayed on the display of the PC 301 (step S12).
[0048]
Then, when AWB adjustment is performed from the display menu screen of the PC 301 (see FIG. 3) (step S13), a filter selection screen as shown in FIG. 4 is displayed, and a filter is selected from this selection screen (step S13). S14). Then, the PC 301 controls the filter moving motor 302 to arrange the selected color temperature filter of the filter member 303 on the photographing optical axis of the imaging device 200 (Step S15).
[0049]
Subsequently, the PC 301 transmits a command indicating the start of AWB adjustment to the control unit 206 of the imaging device 200 (Step S16). Then, the value of the counter K is set to the initial value "0" (step S17). Upon receiving this command (step P13), the control unit 206 of the imaging device 200 sets only the AWB function to OFF and sets the AE function to the operating state (step P14). The ON / OFF setting of the AWB function can be set by communication from the PC 301 and can be set by operating the key input unit 207. Then, photography is always performed with a constant exposure amount by the aperture and shutter of the lens unit controlled by the AE function (step P15).
Here, the photographing operation will be briefly described. A subject image via a lens (not shown) is incident on the CCD 201, and the CCD 201 converts the subject image into an electric signal (analog image data), and outputs R, G, The analog image data of B is output. The variable gain amplifiers 203r and 203b amplify and output the R and B digital image data, respectively, with the gain set by the control unit 206.
[0050]
The AE / AWB evaluation value extraction circuit 205 includes luminance data R1 to Ro (n indicates the number of pixels) for each pixel of R, G, and B digital image data input from the variable gain amplifiers 203r, 203g, and 203b. Three AWB evaluation values ΣR, ΣG, and ΣB (Step P16) and AE evaluation values for luminance calculation are output to the control unit 206 as AWB evaluation values generated based on G1 to Gn and B1 to B1. .
[0051]
The control unit 206 receives the AWB evaluation values ΣR, ΣG, and ΣB (step S18). Subsequently, the PC 301 calculates ΣR / ΣG, ΣB / ΣG (step S19), and sets the value of the counter K to “1”. Is incremented (step S20).
[0052]
Subsequently, the CPU 207 determines whether or not ΣR / ΣG and ΣB / ΣG are within specified values (near 1) (step S21), and if ΣR / ΣG and ΣB / ΣG are within specified values. The R and G gains at this time are sent to the control unit 206 of the imaging device 200 as AWB gain values (step SS22). Upon receiving the R and G AWB gain values, the control unit 206 of the imaging device 200 writes the R and G AWB gain values into the flash memory 208 (Step P17).
[0053]
On the other hand, if ΣR / ΣG and ΣB / ΣG are not within the specified values (near 1) in step S11, the process proceeds to step S23 to determine whether the value of the counter K, that is, the number of adjustments is larger than the specified number N. If K> N, it is determined that the digital camera or the environmental condition is abnormal, and the fact is displayed on the display of the PC 301 to notify the operator (step S25).
[0054]
On the other hand, if K <N is not satisfied, the process proceeds to step S24, where R and G gains are calculated so that ΣR / ΣG and ΣB / ΣG are close to 1, and photographing is performed again together with the calculated R and G gains. Is sent to the control unit 206 of the imaging device 200 (step S24). In response, the control unit 206 of the imaging device 200 sets the calculated R and G gains in the variable gain amplifiers 203r and 203b, performs shooting (Step P15), and sends out the AWB evaluation value again (Step P15). P16). Then, after receiving 後 R, ΣG, and ΣB (step S18), the PC 301 calculates ΣR / ΣG, ΣB / ΣG (step S19), and increments the value of the counter K by “1” (step S20). , ΣR / ΣG and ΣB / ΣG are within the specified values (near 1), and the processing (steps S24, P15, P16, S18, S19, S20, S21, S23) is repeated with the specified number N as a limit.
[0055]
The above processing (steps S14 to S24, steps P13 to P6) is performed for each of the color temperature filters 303a, 303b, 303c, and 303d, and the AWB gain under each illumination condition is written to the flash memory 208.
[0056]
According to the operation example 2 described above, in the adjustment performed by stopping the operation of the AWB function, the color temperature filters are switched while the AE function is operated, and a plurality of color temperature filters having different color temperature characteristics are used. In this photographing, exposure control (AE function) corresponding to each color temperature filter is performed based on the AE evaluation value output from the AE / AW evaluation value extracting circuit 205 to extract the AE / AWB evaluation value. Since the AWB gain value corresponding to each color temperature filter is calculated based on each evaluation value generated based on the RGB luminance data of the digital image data output from the circuit 205, different color temperature characteristics When the AWB gain values are calculated using the filters, the light amount from the subject can be kept constant, and there is little variation between individual imaging devices. It is possible to calculate the high AWB gain of. Even if the brightness of the light source is slightly shifted, stable adjustment can be performed. As a result, the imaging device can properly reproduce white even when the color temperature of the light source changes.
[0057]
Since all settings for the imaging device 200 can be made from an external terminal such as the PC 301, all adjustment work and work for checking the adjustment result can be automatically performed. This eliminates the need for human judgment, and thus makes it possible to make adjustments with small variations among individual imaging devices.
[0058]
In addition, since all settings for the imaging device 200 can be performed from the key operation unit 207 of the imaging device 200, even if a jig such as the adjustment device 300 of the imaging device is not prepared, the setting becomes standard with the imaging device 200. If only the subject is prepared, the adjustment work and the check result of the adjustment result can be performed with a simple configuration.
[0059]
Note that the imaging device according to the present invention is widely applicable to digital cameras, digital video cameras, and the like.
[0060]
In addition, the present invention is not limited to only the above-described embodiment, and can be implemented with appropriate modifications without departing from the spirit of the invention.
[0061]
【The invention's effect】
As described above, the imaging system according to claim 1 converts an object into an electric signal via an optical system and outputs the image signal as a color image signal, and outputs an AWB evaluation value corresponding to the color image signal. AWB evaluation value output means, AE evaluation value output means for outputting an AE evaluation value corresponding to a color image signal, evaluation value external output means for outputting the AWB evaluation value and the AE evaluation value to the outside, and AWB initial gain value Control means for calculating an AWB control value for adjusting the white balance based on the AWB control limit gain value, an AWB control setting means for setting the AWB control value, and a control value for adjusting the exposure amount. AE control means for calculating, AE control value setting means for setting the calculated AE control value, and AWB operation mode setting means for setting whether to stop the AWB operation External setting means for transmitting the AWB control value and the AE control value from the outside, wherein the AWB operation is stopped by the AWB operation mode setting means, the color and brightness of the object are changed by a color conversion optical filter or the like, and the exposure is performed by the AE. The AWB initial gain value and the AWB control limit gain value were calculated while keeping the amount constant.
[0062]
Therefore, when the color conversion optical filter is changed while the operation of the AWB of the imaging device is stopped, even if the brightness and color of the subject change accordingly, the AE operation at that time is performed. The exposure can always be kept constant. As a result, stable evaluation values of the amount and accuracy can be obtained. Further, stable evaluation values under various setting conditions can be checked, and from this data, AWB control values and other AE and AWB setting values under those conditions can be calculated outside the imaging apparatus. . Further, by setting the calculated AWB control value, it is possible to confirm whether the calculated control value is correct.
[0063]
According to a second aspect of the present invention, in the imaging system of the first aspect, an AE operation mode setting unit for setting whether to stop the operation of the AE is further provided. Is stopped, and an AE control value is set from the outside, it is possible to check an evaluation value of an arbitrary exposure amount.
[0064]
In the imaging system according to the third aspect, in the imaging system according to the second aspect, the AE control value, the AWB control value, the AE operation mode, and the AWB operation mode are set from the input unit of the imaging apparatus. The AE control value, the AWB control value, the AE operation mode, and the AWB operation mode can be set at the input unit of the imaging device, and the adjustment work for detecting the AWB constant can be performed with a simple configuration of only the imaging device. Become.
[0065]
Further, in the imaging system according to claim 4, in the imaging system according to claim 2, the AE control value, the AWB control value, the AE operation mode, and the AWB operation mode are set from an external terminal device. The AE control value, AWB control value, AE operation mode, and AWB operation mode can be set from an external terminal such as the above. If a jig for changing an optical filter or a light source is prepared, an automatic adjustment system for detecting an AWB initial gain value and an AWB control limit gain value used for AWB control can be realized. This eliminates the need for human judgment, and thus makes it possible to perform adjustment with small variations among individual imaging devices.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of an imaging system according to an embodiment.
FIG. 2 is a diagram illustrating a configuration of a PC in FIG. 1;
FIG. 3 is a diagram showing an example of a display menu.
FIG. 4 is a diagram illustrating an example of a filter selection screen.
FIG. 5 is a flowchart illustrating an operation example 1 of the AWB adjustment mode.
FIG. 6 is a flowchart illustrating an operation example 2 of the AWB adjustment mode.
[Explanation of symbols]
100 Imaging system
200 Imaging device
300 Adjustment device for imaging device
201 CCD
202 A / D converter
203r Variable gain amplifier for R
203g G variable gain amplifier
203b Variable gain amplifier for B
204 color difference matrix circuit
205 AE / AWB Evaluation Value Extraction Circuit
206 control unit
207 key operation unit
208 Flash memory
209 TimingSG (control signal generation)
301 Personal computer (PC)
302 Filter moving motor
303 Filter member
303a Color temperature filter
303b Color temperature filter
303c Color temperature filter
303d color temperature filter

Claims (4)

An image sensor that converts a subject into an electric signal through an optical system and outputs the signal as a color image signal;
AWB evaluation value output means for outputting an AWB evaluation value according to the color image signal;
AE evaluation value output means for outputting an AE evaluation value according to the color image signal;
Evaluation value external output means for outputting the AWB evaluation value and the AE evaluation value to the outside;
AWB control means for calculating an AWB control value for adjusting the white balance based on the AWB initial gain value and the AWB control limit gain value;
AWB control setting means for setting the AWB control value;
AE control means for calculating a control value for adjusting the exposure amount,
AE control value setting means for setting the calculated AE control value;
AWB operation mode setting means for setting whether or not to stop the AWB operation;
External setting means for transmitting the AWB control value and the AE control value from outside;
With
The AWB operation is stopped by the AWB operation mode setting means, the color and luminance of the object are changed by a color conversion optical filter or the like, and the AWB initial gain value and the AWB control limit gain value are calculated with the exposure amount kept constant by the AE. Characteristic imaging system. 2. The imaging system according to claim 1, further comprising AE operation mode setting means for setting whether to stop the operation of the AE. The imaging system according to claim 2, wherein the setting of the AE control value, the AWB control value, the AE operation mode, and the AWB operation mode is performed from an input unit of an imaging device. The imaging system according to claim 2, wherein the setting of the AE control value, the AWB control value, the AE operation mode, and the AWB operation mode is performed from an external terminal device.

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