JPH11155097A - Digital camera adjusting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly adjust the input signal level of an input image at a low cost with a simple configuration by A/D converting an image signal, outputting an AE evaluating value corresponding to luminance data, generating an AGC adjusting table based on the AE evaluating value and setting the gain of a variable gain amplifier. SOLUTION: A digital camera 100 (CPU 121) is provided with a recording mode for recording image data in a PC card 150, which is obtained by the image pickup of a subject, a display mode for displaying the image recorded in the PC card 150 and a recording and adjusting mode for writing adjusting data in EEPROM 130 in cooperation with a digital camera adjusting device 200. The CPU 121 has a D/A converter and obtains setting data of a D/A converter in gain which is desired to be set in an AGC amplifier 105 based on the AGC adjusting table stored in an EEPROM 130. A value obtained by D/A converting setting data by the D/A converter is set in the AGC amplifier 105 so as to set the gain of the AGC amplifier 105.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a digital camera adjustment system, and more particularly, to a digital camera adjustment system capable of correcting a signal level of an input image.

[0002]

2. Description of the Related Art Recently, digital cameras have become widespread.
In such a digital camera, it is necessary to adjust the signal to an appropriate level at some points in the signal processing system.

For example, in an electronic device described in Japanese Patent Application Laid-Open No. 08-275052, an electronically controlled volume (VCA) is provided at an adjustment point in an arbitrary signal line constituting the electronic device, and the output of this volume is controlled. Level A /
Supply to D converter. Further, a memory in which a reference value for adjustment is recorded is provided, and the reference value from this memory and the detection value from the A / D converter are supplied to a comparator, and the two values are compared. The comparison output from this comparator is, for example, 1
Is supplied to a D / A converter (DAC) of
The control of the electronic volume in accordance with the value from the A converter automatically adjusts the signal level at the adjustment point.

In an image pickup apparatus described in Japanese Patent Application Laid-Open No. 02-060378, an image pickup means for outputting an image pickup signal, a diaphragm for limiting the amount of incident light rays incident on the image pickup means, a signal level of the image pickup signal A variable gain amplifier circuit that corrects, and a control unit that controls the shutter speed of the imaging unit and the gain of the variable gain amplifier circuit based on the signal level of the output signal of the variable gain amplifier circuit. The control target is switched as required to realize functions such as an automatic adjustment mode, an aperture priority mode, and a shutter priority mode.

[0005]

However, in a digital camera, it is difficult to set an input image to an appropriate signal level due to variations in characteristics of a CCD element and a sampling circuit for sampling the output of the CCD element.
There is a problem that a high quality image cannot be obtained.

Therefore, it has been desired to provide a digital camera adjustment system capable of accurately adjusting the input signal level of an input image with a simple configuration, low cost, and accurate.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and provides a digital camera adjustment system capable of accurately adjusting an input signal level of an input image with a simple configuration, at low cost. The purpose is to:

[0008]

In order to solve the above-mentioned problems, a digital camera adjustment system according to a first aspect of the present invention provides an image pickup device that converts subject light via an optical system into an electric signal and outputs the electric signal as an image signal. A variable gain amplifier for correcting the signal level of the image signal; A / D conversion means for A / D converting the image signal output from the variable gain amplifier and outputting the digital image signal as a digital image signal; AE that outputs an AE evaluation value corresponding to the luminance data of
Evaluation value output means, shutter speed setting means for setting a shutter speed, storage means for storing an AGC adjustment table used when setting the gain of the variable gain amplifier, and AGC adjustment stored in the storage means Based on the table, a gain setting means for setting the gain of the variable gain amplifier, and a brightness box for irradiating light of a constant brightness as a light source, when shooting at a shutter speed set by the shutter speed setting means AGC adjustment table creating means for creating the AGC adjustment table based on the AE evaluation value output from the AE evaluation value output means and writing the same in the storage means.

The digital camera adjustment system according to a second aspect of the present invention is the digital camera adjustment system according to the first aspect, wherein the AGC adjustment table creating means uses a luminance box for irradiating light of a constant luminance as a light source and the shutter. When the shutter is changed at least twice or more by the speed setting unit and each image is taken, the AGC adjustment table is created based on the obtained AE evaluation values and written in the storage unit.

According to a third aspect of the present invention, there is provided a digital camera adjustment system, comprising: an image pickup device for converting subject light via an optical system into an electric signal and outputting the signal as an image signal; and a variable gain for correcting a signal level of the image signal. An amplifier, A / D conversion means for A / D converting an image signal output from the variable gain amplifier and outputting it as a digital image signal, and AE for outputting an AE evaluation value corresponding to luminance data of the digital image signal Evaluation value output means, aperture setting means for setting an aperture, a luminance box capable of changing the luminance of irradiation light, and storage means for storing an AGC adjustment table used when setting the gain of the variable gain amplifier. Gain setting means for setting the gain of the variable gain amplifier based on the AGC adjustment table stored in the storage means; The AGC adjustment table is created based on each AE evaluation value obtained by changing the aperture value of the aperture or the aperture value of the aperture by the aperture setting means and photographing each, and writing the AGC adjustment table to the storage means. Adjustment table creating means.

According to a fourth aspect of the present invention, in the digital camera adjustment system according to any one of the first to third aspects, the AGC adjustment table includes an AGC tilt value corresponding to a plurality of gains. And AG
C gain value, and the gain setting means stores the AG shift value.
Calculating setting data based on an AGC slope value and an AGC shift value corresponding to a gain to be set in the variable gain amplifier stored in a C adjustment table, and setting the setting data in the variable gain amplifier; Sets the gain to be set in the variable gain amplifier.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a digital camera adjustment system according to the present invention will be described below in detail with reference to the accompanying drawings.

[Digital camera], [Digital camera adjustment system], [AGC adjustment table creation operation]
Will be described in this order.

[Digital Camera] FIG. 1 is a configuration diagram of a digital camera according to the present embodiment. In the figure,
Reference numeral 100 denotes a digital camera. The digital camera 100 includes a lens 101, a mechanical mechanism 102 including an autofocus, a CCD 103, a CDS circuit 104, a variable gain amplifier (AGC amplifier) 105, and an A / D converter 1.
06, IPP107, DCT108, coder 109,
MCC 110, RAM (internal memory) 111, PC card interface 112, CPU 121, display unit 12
2, operation unit 123, motor driver 125, and SG
(Control signal generation) section 126, strobe 127, battery 128, DC-DC converter 129, and flash memory 130. Also, the PC card 1 that can be detached via the PC card interface 112
50 are connected.

The lens unit includes a lens 101, a mechanical mechanism 102 including an auto focus (AF), an aperture, and a filter section. A mechanical shutter of the mechanical mechanism 102 performs simultaneous exposure of two fields. Lens 10
1 includes, for example, a vari-focal lens, and includes a focal lens group 101a and a zoom lens group 101b. A CCD (Charge Coupled Device) 103 converts a video image input via a lens unit into an electric signal (analog image data). The CDS (correlated double sampling) circuit 104 is a circuit for reducing noise in the CCD type image pickup device.

The AGC amplifier 105 corrects the level of the signal that has been correlated double-sampled by the CDS circuit 104. Further, the A / D converter 106 is connected to the AGC amplifier 1
The analog image data input from the CCD 103 via the input device 05 is converted into digital image data. That is, C
The output signal of the CD 103 is supplied to the CDS circuit 104 and the AG
The signal is converted into a digital signal at an optimum sampling frequency (for example, an integer multiple of the subcarrier frequency of the NTSC signal) by the A / D converter 105 via the C amplifier 105.

The digital signal processor IPP
(Image Pre-Processor) 107, DCT (Discrete Cos)
ine Transform) 108 and coder (Huffman Enco
A der / Decoder) 109 performs various processing, correction, and data processing for image compression / decompression on the digital image data input from the A / D converter 106 by dividing the digital image data into color difference (Cb, Cr) and luminance (Y). Apply. Image compression / decompression unit 107
Performs, for example, orthogonal transformation, which is a process of JPEG-compliant image compression / decompression, and Huffman encoding / decoding, which is a process of JPEG-compliant image compression / decompression.

Further, an MCC (Memory Card Controlle)
An r) 110 temporarily stores the compressed image and records the image on the PC card 150 via the PC card interface 112 or reads the image from the PC card 150.

The CPU 121 uses a RAM (not shown) as a work area in accordance with a program stored in a ROM (not shown), and in accordance with an instruction from the operation unit 123 or an external operation instruction such as a remote controller (not shown). Controls all operations inside the camera. Specifically, the CPU 1
Reference numeral 21 controls an image capturing operation, an automatic exposure (AE) operation, an automatic white balance (AWB) operation, an AF (auto focus) operation, and the like. Further, the CPU 121 executes an AGC adjustment table creating operation in cooperation with the digital camera adjustment device, as described later.

A camera power source is a battery 128, for example, a NiCd, nickel hydrogen, lithium battery, or the like.
The signal is input to the C-DC converter 129 and supplied to the inside of the digital camera.

The display unit 122 is realized by an LCD, LED, EL, or the like, and displays photographed digital image data and decompressed recorded image data. The operation unit 123 includes buttons for externally performing function selection, shooting instructions, and other various settings.

The EEPROM 130 stores adjustment data and the like used when the CPU 121 controls the operation of the digital camera. The adjustment data includes, for example, an AGC adjustment table (see FIG. 5).

The digital camera 100 (CPU 1
21) converts image data obtained by imaging a subject into a PC
Recording Mode for Recording on Card 150 and PC Card 15
The display mode includes a display mode for displaying an image recorded at 0, a recording / adjustment mode for writing adjustment data to the EEPROM 130 in cooperation with the digital camera adjustment device 200, and the like.

FIG. 2 is a diagram showing an example of a specific configuration of the IPP 107. As shown in FIG. 3, the IPP 107 separates the digital image data input from the A / D converter 106 into R, G, and B color components.
A signal interpolating unit 1072 for interpolating the separated R, G, B image data, a pedestal adjusting unit 1073 for adjusting the black level of each of the R, G, B image data, and each of the R, B images A white balance adjustment unit 1074 for adjusting the white level of the data; a digital gain adjustment unit 1075 for correcting each of the R, G, and B image data with a gain set by the CPU 121; a gamma conversion unit 1076 for performing γ conversion, a matrix unit 1077 for separating RGB image data into color difference signals (Cb, Cr) and a luminance signal (Y), a color difference signal (Cb, Cr), and a luminance signal (Y) And a video signal processing unit 1078 that creates a video signal based on the video signal and outputs the video signal to the display unit 122.

Further, the IPP 107 includes a Y operation unit 1079 for detecting the luminance data (Y) of the image data after the pedestal adjustment by the pedestal adjustment unit 1073, and a Y operation unit 1
A BPF 1080 that passes only a predetermined frequency component of the luminance data (Y) detected at 079, an AF evaluation value circuit 1081 that outputs a digital count value corresponding to the luminance data (Y) that has passed through the BPF 1080 to the CPU 121 as an AF evaluation value. , An AE evaluation value circuit 1082 that outputs a digital count value corresponding to the luminance data (Y) detected by the Y operation unit 1079 to the CPU 121 as an AE evaluation value;
Y for detecting luminance data (Y) of each of G and B image data
An arithmetic unit 1083 and an AWB evaluation value circuit 108 which outputs a digital count value corresponding to the luminance data (Y) detected by the Y arithmetic unit 1083 to the CPU 121 as an AWB evaluation value.
4 and a CPU as an interface between the CPU 121
An I / F 1085 and a DCTI / F 1086 as an interface with the DCT 108 are provided.

The AE evaluation value circuit 1082 described above converts the screen (the light receiving screen of the CCD 103) into six AE areas y_1 to y_6 (specifically, y_
1 area, upper right y_2 area, lower left y_3 area,
Lower right y_4 area, center y_5 area, center y_
An AE evaluation value obtained by weighting and calculating the luminance value of each area when divided into six areas is output. More specifically, the Y operation unit 1079 outputs the luminance data of each pixel of the image data to the AE evaluation value circuit 1082, and the AE evaluation value circuit 1082 converts the luminance data in each of the AE areas y_1 to y_6. The integrated value is calculated as a luminance value, and a value obtained by weighting the calculated luminance value of each of the AE areas y_1 to y_6 is output to the CPU 121 as an AE evaluation value.

Next, the operation of the CPU 121 for setting a gain by setting a control voltage to the AGC amplifier 105 will be described.

FIG. 4 is a diagram showing a relationship between a control voltage (Control Voltage) and an output gain (Measured Gain) of AGC amplifier 105 in the present embodiment.
In the figure, the horizontal axis represents the control voltage (Control Voltage) of the AGC amplifier 105 and the vertical axis represents the AGC amplifier 10.
5 shows the output gain (Measured Gain).

FIG. 5 is a diagram showing the contents of the AGC adjustment table stored in the EEPROM 130. The AGC adjustment table includes a TV value (shutter speed), an AGC shift value (agc_def, agc_def_1 to 3, and agc_def_1).
33 — m) and AGC slope values (agc — k — plus, ag
c_k_plus_1 ~ 3, agc_k_plus_minus_0 ~ 3
) Are stored in association with each other. Hereinafter, variables of the AGC adjustment table will be described.

The variables shown below have units of Ev (Lv, T
v and Av have the same meaning. ), 1/16 Ev
Is set to 1.

AGC gradient values (agc_k_plus, agc_
k_plus1-3, agc_k_plus_minus_0-3):
The AGC amplifier 105 sets a value (D / A value)
Since it does not change linearly as shown in FIG. 4, it is a calculated slope value in each gain range for approximating the characteristic curve shown in FIG. 4 to a linear expression.

Agc_k_plus: slope data of D / A converter setting data of 3 dB to 6 dB (± 0 Ev to +0.5 Ev) agc_k_plus_1: D / A conversion of 6 dB to 9 dB (± 0.5 Ev to +1 Ev) Slope data of converter setting data agc_k_plus_2: 9 dB to 12 dB (± 1 Ev to +1.5 Ev) D / A converter slope data of setting data agc_k_plus_3: 12 dB to 15 dB (± 1.5 Ev to +2 Ev) Slope data of D / A converter setting data agc_k_plus_minus_0: 3 dB to 0 dB (± 0 Ev to −0.5 Ev) slope data of D / A converter setting data agc_k_plus_minus_1: 0 dB to −3 dB (-0.5Ev to -1Ev) D / A converter setting data gradient data agc_k_plus_minus_2: -3dB to -6dB (-1.0Ev to -1.5Ev) )) D / A converter setting data gradient data agc_k_plus_minus_3: -6 dB to -9 dB (-1.5 Ev to -2 Ev) D / A converter setting data gradient data

AGC shift values (agc_def, agc_de
f1-3, agc_def_1-3_m): agc_k_plus,
agc_k_plus1 ~ 3, agc_k_plus_minus_0 ~
3) Each shift value. agc_def: D / A converter setting data at 3 dB (± 0 Ev) agc_def_1: D / A converter setting data at 6 dB (± 0.5 Ev) agc_def_2: 9 dB (± 1. D / A converter setting data at 0Ev) agc_def_3: D / A converter setting data at 12dB (± 1.5Ev) agc_def_1_m: 0dB (-0.5Ev) D / A converter setting data agc_def_2_m: When D / A converter setting data is -3dB (-1.0Ev) agc_def_3_m: When -6dB (-1.5Ev) D / A converter setting data

The CPU 121 has a built-in D / A converter, and based on an AGC adjustment table stored in the EEPROM 130, the AGC amplifier 10
Setting data agc of D / A converter of gain to be set to 5
_Data (D / A output setting data of the CPU 121,
With this data, the gain of the AGC amplifier 15 can be set. ). Then, the setting data is set by the D / A converter.
A value (control voltage) obtained by D / A conversion of agc_data is set in the AGC amplifier 105, and the gain of the AGC amplifier 105 is set.

For example, when 10.5 dB (+1.25 Ev) is set as a gain in the AGC amplifier 105, agc_def2 and agc_k_plus_2 of the above adjustment data are set.
And setting data ag to be set in the D / A converter
Find c_data.

[Digital Camera Adjustment Apparatus] FIG. 6 is a diagram showing an external configuration of a digital camera adjustment apparatus 200 according to the present embodiment, and FIG. FIG. 2 is a diagram showing a block configuration of a camera adjustment system 300.

The digital camera adjustment device 200 shown in FIGS. 6 and 7 includes a digital camera supply power supply 201 for supplying power to the digital camera 100 and an adapter 20 for GPIB control of the digital camera supply power supply 201.
2, a monitor 203 for displaying an image captured by the digital camera 100, a vector scope 204 for displaying the amplitude and phase of a color signal (RGB) scanned by the digital camera 100 in a vector form, and a monitor 203 for video signal observation. Waveform monitor 205, luminance box 206, digital camera 100 and the above-described measuring equipment (vector scope 204, waveform monitor 205)
207), a display 208 that is a display device of the computer 207 and displays an adjustment menu, etc., a GPIBI / F 209 mounted on the main body of the computer 207, and the digital camera 100 fixed and supplied with a digital camera. Power supply 201, RS-232
Adjusting jig body 210 for signal connection such as C, VIDEO, etc.
And a control box 211.

FIG. 8 is a diagram showing the configuration of the computer 207. As shown in FIG. 7, the computer 207 includes an input unit 2071 for giving an operation instruction, a CPU 2072 for controlling the entire computer device, and the CPU 2
RO that stores various control programs for operating 072
M2073, RAM 2074 used as a work area of CPU 2072, and I / O for data communication.
/ F2075. The control program includes, for example, an EEPROM of the digital camera 100.
130 has an adjustment data creation program for writing adjustment data such as an AGC adjustment table.

[Creation of AGC Adjustment Table] Next, the procedure of creating the AGC adjustment table executed in cooperation with the digital camera 100 and the digital camera adjustment device 200 will be described with reference to FIG.
This will be described with reference to the flowchart shown in FIG. FIG.
It is a flowchart for demonstrating the procedure of a GC adjustment table preparation.

In creating the AGC adjustment table, a luminance box 206 for emitting light of a constant luminance level is used.
(For example, Lv12 (ISO100)) is used as an illumination source.

First, as shown in FIG. 7, the digital camera 100 is connected to the jig main body 2 of the digital camera adjustment device 200.
When the digital camera 100 and the digital camera adjustment device 200 are powered on, the digital camera 100 and the digital camera adjustment device 200 are initialized (steps S1 and P1).
08, a display menu is displayed (step S
2).

Then, in the digital camera 100, the adjustment and recording modes are set (step P2). Also,
In the digital camera adjustment device 200, the display 20
8 is selected from the menu screen (step S3), the CP of the computer 207 is activated.
The U2072 transmits a command indicating the start of the AGC adjustment table creation process to the CPU 121 of the digital camera 100 via the RS232C cable (Step S)
4).

Upon receiving this command, the CPU 121 of the digital camera 100 sets the AE, AWB, and AF functions to a stopped (prohibited) state (step P).
3). Then, the CPU 2072 of the computer 207
Sets the aperture to a fixed value (for example, F4 (Av 4)), and sets a proper exposure level for the luminance
A command for setting the D shutter speed (Tv value) is transmitted to the CPU 121 of the digital camera 100 (step S5). Upon receiving this command, the CPU 121 of the digital camera 100 sets a CCD shutter speed (Tv value) in the luminance box 206 so that the exposure level is appropriate (step P4). When the aperture is fixed at F4 (Av4), for example, an appropriate exposure level is obtained when the CCD shutter speed is about 1/255 second (Tv 7.8). The Tv set value at this time is 0x7D (Tv value x 0x10).

The CPU 2072 of the computer 207
A command instructing the setting of the initial setting value of the AGC amplifier 105 (variable gain amplifier) is transmitted to the C
The data is transmitted to the PU 121 (step S6). Upon receiving this command, the CPU 121 of the digital camera 100 sets an initial setting value in the AGC amplifier 105 (variable gain amplifier) (Step P5).

The CPU 20 of the computer 207
Reference numeral 72 denotes a command of the digital camera 100 for instructing the capture of the AF evaluation value, the AE evaluation value, and the AWB evaluation value.
The data is transmitted to the PU 121 (step S7). Upon receiving this command, the CPU 121 of the digital camera 100 performs shooting under the set conditions (step P6),
AF evaluation value circuit 1081, AE evaluation value circuit 1 of P107
082 and the AF evaluation value, the AE evaluation value, and the AWB evaluation output from the AWB evaluation value circuit 1084, respectively.
After being expanded in the RAM, the CPU 2 of the computer 207
072 (Step P7).

The CPU 2072 of the computer 207
When the AF evaluation value, the AE evaluation value, and the AWB evaluation are received, it is determined whether the AE evaluation value is within a specified range (step P9). The command is sent to the AGC amplifier 105 (variable gain amplifier) to set a different set value, that is, a command to change the set value of the AGC amplifier 105 (step S6). Upon receiving this command, the CPU 121 of the digital camera 100 changes the AGC set value set in the AGC amplifier 105 (variable gain amplifier) (Step P5). Specifically, when the AE evaluation value is larger than the specified range, AG
When the C set value is set to a large value and the AE evaluation value is smaller than a specified range, the AGC set value is set to a small value. Then, shooting is performed again (step P6), and the AF evaluation value, the AE evaluation value, and the AWB evaluation are determined by the CPU of the computer 207.
2072 (step P7). The same processing is performed until the AE evaluation value falls within the standard range (steps S6 to S9, P
5 to P7) are repeated. If the AE evaluation value does not fall within the standard value even when the setting value of the AGC amplifier 105 is changed, it is determined that the AE evaluation value is abnormal, and the CCD 103
It may be determined that there is an abnormality such as.

In step S9, if the AE evaluation value is within the specified range, the AGC amplifier 1
A command for instructing the writing of the set value of 05 in the EEPROM 130 is transmitted to the CPU 121 of the digital camera 100 (step S11).

The CPU 121 of the digital camera 100
When this command is received, the set value of the AGC amplifier 105 whose AE evaluation value falls within the specified range is changed to the AGC shift value (ag
c_def) is written in the EEPROM 130 (step P8).

The above processing (steps S4 to S11, P3 to
P8) to change the shutter speed (Tv) (0x85, 0x
8d, 0x95, 0x9d), and performs AGC shift values (agc_def1-3, ag) for each shutter speed (Tv).
c_def_1 to 3_m) are written in the EEPROM 130.

Then, the CPU 121 sets the AGC shift values (agc_def, agc_def1 to 3, agc_def_1 to 3_
m) to the AGC slope values (agc_k_plus, agc_k_pl
us1 to 3 and agc_k_plus_minus_0 to 3), respectively, to calculate the TV value (shutter speed) and the AGC shift adjustment values (agc_def, agc_de) as shown in the above figure.
f_1 to 3, agc_def_1 to 3_m) and AGC
Slope value (agc_k_plus, agc_k_plus_1 ~ 3, ag
AGC correlated with c_k_plus_minus_0 to 3)
Create an adjustment table.

In the above description, when the AGC adjustment table is created, the shutter speed is changed to calculate the AGC shift value and the AGC inclination value.
Alternatively, the AGC shift value and the AGC slope value may be calculated by changing the aperture value and the luminance value of the luminance box 126.

[0052]

According to a first aspect of the present invention, there is provided a digital camera adjustment system, comprising: an image sensor for converting subject light via an optical system into an electric signal and outputting the signal as an image signal; and a variable gain for correcting a signal level of the image signal. An amplifier, A / D conversion means for A / D converting an image signal output from the variable gain amplifier and outputting it as a digital image signal, and AE for outputting an AE evaluation value corresponding to luminance data of the digital image signal Evaluation value output means, shutter speed setting means for setting a shutter speed, storage means for storing an AGC adjustment table used when setting the gain of the variable gain amplifier, and AGC adjustment stored in the storage means A gain setting means for setting a gain of the variable gain amplifier based on a table; Creating an AGC adjustment table based on the AE evaluation value output from the AE evaluation value output means when shooting is performed at the shutter speed set by the speed setting means, and writing the AGC adjustment table into the storage means Means, so that low cost,
Further, it is possible to provide a digital camera adjustment system capable of accurately adjusting the input signal level of an input image. In addition, adjustment after the completion of the camera is possible, and there is no mechanical change required for adjusting the AGC set voltage so that the AE evaluation value is within the specified value by setting the electronic shutter. Therefore, the adjustment can be performed quickly.

The digital camera adjustment system according to a second aspect of the present invention is the digital camera adjustment system according to the first aspect, wherein the AGC adjustment table creating means uses a luminance box for emitting light of a constant luminance as a light source, and When shooting is performed by changing the shutter speed at least twice or more by the speed setting unit, the AGC adjustment table is created and written in the storage unit based on the obtained AE evaluation values. It is possible to easily create an AGC table.

According to a third aspect of the present invention, there is provided a digital camera adjustment system, comprising: an image pickup device for converting subject light via an optical system into an electric signal and outputting it as an image signal; and a variable gain amplifier for correcting a signal level of the image signal. A / D conversion means for A / D converting an image signal output from the variable gain amplifier and outputting it as a digital image signal, and AE evaluation value output for outputting an AE evaluation value corresponding to luminance data of the digital image signal Means, aperture setting means for setting an aperture, a luminance box capable of changing the luminance of irradiation light, storage means for storing an AGC adjustment table used when setting the gain of the variable gain amplifier, and the storage means Gain setting means for setting the gain of the variable gain amplifier based on the AGC adjustment table stored in the luminance box, and setting the luminance or the aperture of the luminance box using the luminance box as a light source. Means for changing the aperture value of the aperture by means and generating an AGC adjustment table based on each of the AE evaluation values obtained when each image is taken, and writing the AGC adjustment table to the storage means. Therefore, it is possible to provide a digital camera adjustment system capable of accurately adjusting the input signal level of an input image at low cost.

A digital camera adjustment system according to a fourth aspect of the present invention is the digital camera adjustment system according to any one of the first to third aspects, wherein the AGC adjustment table includes an AAGC slope value corresponding to each of a plurality of gains. AG
C gain value, and the gain setting means calculates setting data based on the AGC shift value and the AGC slope value corresponding to the gain to be set in the variable gain amplifier, stored in the AGC adjustment table. Since the gain to be set in the variable gain amplifier is set by setting the setting data in the variable gain amplifier, it is possible to easily set a desired gain in the variable gain amplifier.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a digital camera according to an embodiment.

FIG. 2 is a diagram illustrating an example of a specific configuration of the IPP of FIG. 1;

FIG. 3 is a diagram showing an AE area of the CCD shown in FIG. 1;

FIG. 4 shows a control voltage (Control V) of an AGC amplifier.
FIG. 6 is a diagram illustrating a relationship between the output gain (Measurement Gain) and the output gain (Measured Gain).

FIG. 5 is a diagram illustrating an example of an AGC adjustment table.

FIG. 6 is a diagram showing an external configuration of a digital camera adjustment device according to the present embodiment.

FIG. 7 is a configuration diagram of a digital camera adjustment system according to the present embodiment.

FIG. 8 is a diagram showing a configuration of a computer of FIG.

FIG. 9 is a flowchart illustrating a processing procedure for creating an AGC adjustment table.

[Explanation of symbols]

REFERENCE SIGNS LIST 100 Digital camera 101 Lens 102 Mechanical mechanism including autofocus 103 CCD (charge coupled device) 104 CDS (correlated double sampling) circuit 105 Variable gain amplifier (AGC amplifier) 106 A / D converter 107 IPP (Image Pre-Processor) ) 108 DCT (Discrete Cosine Transform) 109 Coder (Huffman Encoder / Decoder) 110 MCC (Memory Card Controller) 111 RAM (Internal Memory) 112 PC Card Interface 121 CPU 122 Display Unit 123 Operation Unit 125 Motor Driver 126 SG Unit 127 Strobe 128 Battery 129 DC-DC converter 130 EEPROM 150 PC card 200 Digital camera adjustment device 201 Digital camera supply power supply 202 Adapter 203 Monitor 204 Vectorco Step 205 Waveform monitor 206 Luminance box 207 Computer 208 Display 209 GPIBI / F 210 Adjusting jig body 211 Control box 300 Digital camera adjustment system 1071 Color separation unit 1072 Signal interpolation unit 1073 Pedestal adjustment unit 1074 White balance adjustment unit 1075 Digital gain adjustment Unit (digital gain adjusting means) 1076 γ conversion unit 1077 matrix unit 1078 video signal processing unit 1079 Y operation unit 1080 BPF 1081 AF evaluation value circuit 1082 AE evaluation value circuit 1083 Y operation unit 1084 AWB evaluation value circuit 1085 CPU I / F 1086 DCTI / F 1075r, 1075g, 1075b Multiplier 2071 Input unit 2072 CPU 2073 ROM 2074 RAM 2075 I / F

Claims (4)

[Claims] 1. An image pickup device that converts subject light via an optical system into an electric signal and outputs the signal as an image signal, a variable gain amplifier that corrects a signal level of the image signal, and an output from the variable gain amplifier A / D conversion means for A / D converting an image signal and outputting it as a digital image signal; AE evaluation value output means for outputting an AE evaluation value according to luminance data of the digital image signal; and setting a shutter speed. Shutter speed setting means; storage means for storing an AGC adjustment table used when setting the gain of the variable gain amplifier; gain of the variable gain amplifier based on the AGC adjustment table stored in the storage means And a shutter speed set by the shutter speed setting means, using a brightness box for irradiating light of a constant brightness as a light source. And an AGC adjustment table creating unit that creates the AGC adjustment table based on the AE evaluation value output from the AE evaluation value output unit when the shooting is performed, and writes the AGC adjustment table in the storage unit. Digital camera adjustment system. 2. The method according to claim 1, wherein the AGC adjustment table creating means uses a luminance box for irradiating light of a constant luminance as a light source, and changes the shutter speed at least twice by the shutter speed setting means, and performs photographing. 2. The digital camera adjustment system according to claim 1, wherein the AGC adjustment table is created based on each of the obtained AE evaluation values and written into the storage unit. 3. An image pickup device that converts subject light via an optical system into an electric signal and outputs the signal as an image signal, a variable gain amplifier that corrects a signal level of the image signal, and an output from the variable gain amplifier. A / D conversion means for A / D converting an image signal and outputting it as a digital image signal; AE evaluation value output means for outputting an AE evaluation value according to luminance data of the digital image signal; Setting means, a luminance box capable of changing the luminance of irradiation light, storage means for storing an AGC adjustment table used when setting the gain of the variable gain amplifier, and an AGC adjustment table stored in the storage means Gain setting means for setting the gain of the variable gain amplifier based on the brightness of the brightness box as a light source, and the brightness of the brightness box or the aperture setting by the aperture setting means. An AGC adjustment table creating unit that creates the AGC adjustment table based on each AE evaluation value obtained when the aperture value is changed and each image is captured, and writes the AGC adjustment table in the storage unit. Digital camera adjustment system. 4. The AGC adjustment table stores an AAGC slope value and an AGC shift value respectively corresponding to a plurality of gains, and the gain setting means controls the variable gain amplifier stored in the AGC adjustment table. Setting data is calculated based on the AGC slope value and the AGC shift value corresponding to the gain to be set, and the gain to be set in the variable gain amplifier is set by setting the setting data in the variable gain amplifier. The digital camera adjustment system according to claim 1, wherein: