JPH10136400A - Color image pickup device and color image pickup method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the color image pickup device and the color image pickup method in which level balance is easily adjusted even with respect to an achromatic color of an intermediate gradation between white and black colors. SOLUTION: When data denoting a level of optimum color adjustment data are fed from an information processing unit via an SPC 63, a CPU 69 gives the data to lookup tables (LUT) 45R, 45G, 45B via, e.g. a buffer memory 65. Data in the LUT 45R, 45G, 45B, are rewritten based on data received from the buffer memory 65, then a level of color image pickup data R, G, B fed from A/D converters 44R, 44G, 44B is changed to adjust an optimum color balance and then the color balance of the color image pickup data of the camera size, that is, the main line side is adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a color image pickup apparatus and a color image pickup method capable of adjusting the color balance of a captured still image.

[0002]

2. Description of the Related Art Normally, a camera device can obtain a constant color reproducibility by performing white balance adjustment and black balance adjustment even if the color temperature of a subject varies depending on the light source.

In the white balance adjustment, an image of a white subject is taken and the level is adjusted so that the signal level of each color signal at the white luminance point becomes equal. In the black balance adjustment, the shutter of the lens is closed once. Thus, the black level of the image pickup signal is sampled, and the signal level is adjusted so that the black level of each color signal becomes equal.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and it is possible to easily perform level balance adjustment for an achromatic color having an intermediate gradation between white and black. It is an object to provide a color imaging device and a color imaging method.

[0005]

A color image pickup apparatus according to the present invention is an image pickup means for picking up an image of a subject to generate a color image pickup signal composed of a plurality of color signals, and a correlation between signal levels of the plurality of color signals. A level balance control data generating means for generating level balance control data based on
The exposure amount adjusting means for adjusting the exposure amount of the imaging means, and the level balance control data generated by the level balance control data generating means for each of the exposure amounts adjusted by the exposure adjusting means, Storage means for storing the signal levels of the plurality of color signals in association with each other; and reading out the level balance control data corresponding to the respective color signals from the storage means based on the signal levels of the respective color signals. Level balance control means for controlling.

In a color imaging method according to the present invention, a subject is imaged to generate a color imaging signal composed of a plurality of color signals, and level balance control data is generated based on a correlation between signal levels of the plurality of color signals. In each of the exposure amounts generated and adjusted by the exposure adjusting means, the level balance control data is stored in association with the signal levels of the plurality of color signals at the respective exposure amounts, and based on the signal levels of the respective color signals. Then, the stored level balance control data is read, and the signal levels of the respective color signals are controlled based on the read level balance control data.

[0007] A color image pickup apparatus according to the present invention includes an image pickup means for picking up an image of a subject to generate a color image pickup signal composed of a plurality of color signals, and an image of a plurality of predetermined regions on a screen represented by the color image pickup signal. A predetermined region extracting means for sequentially extracting the color image pickup signal of the portion representing the, based on the correlation between the signal levels of the plurality of color signals included in each of the predetermined regions,
Level balance control data generating means for generating level balance control data; storage means for storing the level balance control data in association with the signal levels of the plurality of color signals in each of the predetermined areas; Level balance control means for reading out the level balance control data corresponding to each color signal from the storage means based on the level and controlling the signal level of each color signal is provided.

According to the color imaging method of the present invention, a subject is imaged to generate a color imaging signal composed of a plurality of color signals, and a portion representing an image of a plurality of predetermined regions in a screen represented by the color imaging signal is provided. Sequentially extract the color imaging signals of
Based on the correlation between the signal levels of the plurality of color signals included in each of the predetermined areas, level balance control data is generated, and the level balance control data is generated based on the signal levels of the plurality of color signals in each of the predetermined areas. The stored level balance control data is read out based on the signal level of each color signal stored in association with each other, and the signal level of each color signal is controlled based on the read level balance control data.

[0009] A color image pickup apparatus according to the present invention includes: an image pickup means for picking up an image of a subject to generate a color image pickup signal composed of a plurality of color signals; a display means for displaying an image based on the color image pickup signal; Area specifying means for specifying a desired area in the image displayed by the image processing apparatus, and a correlation between signal levels of a plurality of color signals constituting the color imaging signal corresponding to the area specified by the area specifying means. Level balance control data generating means for generating level balance control data; and storage means for storing the level balance control data in association with the signal levels of the plurality of color signals in an area specified by the area specifying means. And level balance control data corresponding to each color signal from the storage means based on the signal level of each color signal. Reading, characterized in that a level balance control means for controlling the signal levels of the respective color signals.

A color imaging method according to the present invention captures a subject, generates a color imaging signal composed of a plurality of color signals, displays an image based on the color imaging signal, and displays a desired image among the displayed images. Specify a region, based on the interrelationship of the signal levels of a plurality of color signals constituting the color imaging signal corresponding to the specified region, generate level balance control data, the level balance control data,
Stored in association with the signal levels of the plurality of color signals in each of the predetermined areas, based on the signal level of each of the color signals, read the level balance control data once stored, based on the read level balance control data,
The signal level of each color signal is controlled.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

The present invention is applied to, for example, an imaging system having a configuration as shown in FIG. This imaging system simultaneously adjusts white balance of color imaging signals R (red), G (green), and B (blue) obtained by imaging a subject with the color imaging device 1 at the time of fine adjustment of gamma correction. It also has a function of performing level balance adjustment of color signals for all intermediate colors from white to black, that is, gray balance adjustment by performing fine adjustment of the adjustment.

A color image pickup apparatus 1 in this image pickup system includes a camera head 3 for photographing a subject through an image pickup lens 2 and outputting an image pickup signal, and converting a color image pickup signal from the camera head 3 into image data for storage. And supplies the stored image data and the like to the information processing device 5 and the like.
A digital processor 4 for adjusting the balance of the color signal level with respect to the stored image data.

The imaging system includes an information processing device 5 for controlling data processing by the digital processor 4 and a printer 6 for outputting an image of a subject based on image data transmitted from the color imaging device 1. A personal computer 7 capable of performing the same control as the information processing apparatus 5, and a monitor device 8 for displaying an image of a subject photographed by the camera head 3.

The imaging system further includes a remote controller (hereinafter, referred to as a remote controller) 9 for performing operations such as flash synchronous photography, and an LCD for displaying an image of a subject being photographed by the camera head 3.
(Liquid Crystal Display) Viewfinder 10,
A strobe light generator 12 and a strobe light emitting device 12 are provided, and when the release button 9A of the remote controller 9 is pressed, the strobe light emitting device 12 flashes as required.

Specifically, as shown in FIG. 2, for example, the camera head 3 includes a CCD (Charge Coupled Device) image sensor 21 and a correlated double sampling (hereinafter, referred to as CD).
Circuit 22, a preamplifier circuit 23, a gain control circuit 24, a white balance circuit 25,
6, a gamma correction circuit 27, an output driver 28, and the like.

The CCD image sensor 21 is, for example, a three-panel type of progressive scan, and responds to three primary color light components decomposed by a photodecomposition prism 37 from imaging light incident from the imaging lens 2 via an optical low-pass filter 36. And color image signals R (red), G (green), B
(Blue).

The CDS circuit 22 has respective color image pickup signals R, G, B read from the CCD image sensor 21.
Is subjected to correlated double sampling, and color image signals R, G, and B with reduced random noise are supplied to the preamplifier circuit 23.

The gain of each of the color image signals R, G, B amplified by the preamplifier circuit 23 is controlled by a gain control circuit 24 controlled by a CPU 30 and supplied to a white balance circuit 25.

The white balance circuit 25 performs white clipping or the like on each color image pickup signal R, G, B as necessary, and supplies each color image pickup signal R, G, B processed here to the penny circuit 26.

The pre-knee circuit 26 compresses the signal levels of the respective color image pickup signals R, G, and B which are equal to or higher than a predetermined knee level, and supplies the compressed signal levels to the gamma correction circuit 27. The gamma correction circuit 27 performs signal level conversion on each of the color imaging signals R, G, and B based on, for example, a non-linear curve of 0.45γ, and outputs each color imaging signal R, G, and B to an output driver. 28, and are supplied to the digital processor 4 via the terminals 29R, 29G, and 29B.

The camera head 3 includes a microcomputer (hereinafter referred to as a CPU) 30 for controlling the gain control circuit 24, the white balance circuit 25, the penny circuit 26, the gamma correction circuit 27, and the like.
EEPROM (Electrical) that stores the control program of
ly Erasable Programmable ROM) 31, a sync generator 33 for generating a synchronizing signal to drive the CCD image sensor 21, a timing generator 34 for generating a CCD reading pulse or the like based on the synchronizing signal from the sync generator 33, Generator 34
CCD driver 3 for amplifying CCD readout pulses from CCD
5 is provided.

The CPU 30 controls a control signal supplied from the digital processor 4 via a terminal 32, an EEPROM,
Based on the control program stored in the control unit 31, for example, control of gamma correction, generation of a synchronization signal by the sync generator 27, and control of the aperture of the imaging lens 2 are controlled.

The sync generator 33 generates a vertical synchronizing signal and a horizontal synchronizing signal, and supplies these synchronizing signals to the timing generator 34. The timing generator 28 determines the CC based on these synchronization signals.
A D read pulse, a vertical transfer pulse, and a horizontal transfer pulse are generated. The CCD driver 29 drives the CCD image sensor 21 with these CCD reading pulses and the like. Thereby, the CCD image sensor 21 outputs, for example, the color imaging signals R, G, and B at 24 frames per second.

As shown in FIG. 3, for example, the digital processor 4 includes amplifying circuits 42R, 4 which amplify the color image signals R, G, B supplied from the camera head 3, respectively.
2G, 42B; cable compensators 43R, 43G, 43B for compensating cable length for each color image signal from the amplifier circuits 42R, 42G, 42B;
Analog / digital (hereinafter, referred to as A / D) converters 44R, 44 for converting color imaging signals R, G, B from R, 43G, 43B into color imaging data R, G, B, respectively.
G, 44B and A / D converters 44R, 44G, 44
Look-up tables (hereinafter referred to as LUTs) 45R and 45 for respectively converting the gradations of the color imaging data from B
G, 45B.

The amplifying circuits 42R, 42G, 42B are supplied with the color imaging signals R, G, B from the camera head 3 via the terminals 41R, 41G, 41B, and amplify these color imaging signals R, G, B. Cable compensators 43R, 43G,
43B.

Cable compensators 43R, 43G, 43B
Is for compensating for the deterioration of the frequency characteristic according to the length of the cable with respect to each of the amplified color imaging signals, and converting the obtained color imaging signals into A / D converters 44R, 44G, 4
4B.

A / D converters 44R, 44G, 44B
For example, using a sampling clock (not shown) based on a synchronizing signal from the camera head 3, for example, converts one sample value into 10-bit color imaging data and supplies this color imaging data to the LUTs 45R, 45G, and 45B.

The LUTs 45R, 45G, and 45B store the level conversion data as table data and perform gray balance correction of the color imaging data gamma-corrected by the gamma correction circuit 27, as shown in FIG. Level detectors 451R, 451G, to which 10-bit color imaging data are supplied from the D converters 44R, 44G, 44B
451B and the level detectors 451R, 451G, 4
Table memories 452R and 45 from which table data is read using the detection output by 51B as a read address.
2G, 452B. Table memory 452R, 4
Each of 52G and 452B has, for example, a 512K × 8-bit static random access memory (SRAM: St.
An 8-bit level conversion data supplied from a random access memory (RAM) 67 via a buffer memory 65 is written as table data.

Then, the LUTs 45R, 45G, 45B
Converts the 10-bit color imaging data supplied from the A / D converters 44R, 44G, and 44B into 8-bit color imaging data, and converts the obtained color imaging data into a write control circuit 4.
6 and dynamic random access memory (DRAM: Dy
(Namic Random Access Memory) controller 55.

The digital processor 4 has an LU
Color imaging data R, G, T45R, 45G, 45B
A write control circuit 46 for controlling writing of B, a video RAM (VRAM: Video RAM) 47 for storing image data of each color based on the control of the write control circuit 46, and a VRAM 47
A read control circuit 48 for controlling the reading of each color image data stored in the memory, and an LUT 49R for converting the gradation of each color image data read from the read control circuit 48,
49G, 49B, and digital / analog (hereinafter, referred to as D / A) converters 51R, 51G, 51B for converting the color imaging data R, G, B from the LUTs 49R, 49G, 49B into respective color imaging signals R, G, B. , A low-pass filter (LPF: Low Pas
s Filter) 52R, 52G, 52B and a matrix encoder 53.

The write control circuit 46 supplies a write clock of 24 MHz to the VRAM 47, and writes the color image data R, G, B supplied at a rate of 24 frames per second to the VRAM 47 in synchronization with the write clock.

The read control circuit 48 supplies a read clock of 30 MHz to the VRAM 47, and reads out 30 frames of color image data per second from the VRAM 47 in synchronization with the read clock.
G and B are supplied to LUTs 49R, 49G and 49B.

The LUTs 49R, 49G, and 49B are composed of, for example, 512K × 8-bit SRAMs, and store LUT data supplied from the RAM 67 via the buffer memory 66. Specifically, LUTs 49R, 49G, 4
9B, for example, the color reproduction, gradation reproduction, etc. (image quality) of the monitor device 8 and the image quality of the image displayed by the cathode ray tube of the display unit provided in the information processing device 5 and the image printed out by the printer 6 are equal. Such characteristic data is stored as table data, and the level correction of the color imaging data is performed based on the characteristic data. And LUT49
R, 49G, and 49B convert the gradations of the color imaging data R, G, and B into R, G, and B independently, and convert the obtained color imaging data into D.
/ A converters 51R, 51G, 51B.

D / A converters 51R, 51G, 51B
Converts, for example, color imaging data in which one sample value consists of 8 bits into color imaging signals R, G, and B, and supplies the color imaging signals R, G, and B to the LPFs 52R, 52G, and 52B. It should be noted that adders 50R, 50G, 50B to which menu data read from a ROM 68 in which a program for controlling the entire system is stored in advance are provided in front of the D / A converters 51R, 51G, 51B. ing.

The LPFs 52R, 52G, and 52B pass only predetermined bands of the color image signals R, G, and B, and supply the color image signals from which extra band components have been removed to the matrix encoder 53.

The matrix encoder 53 converts the color imaging signals R, G, B into, for example, a luminance signal Y and a color difference signal C, converts these signals Y, C into a composite color video signal of, for example, the NTSC system, Is supplied to the monitor device 8 via the. Further, the matrix encoder 53 may output the color imaging signals R, G, B as they are. Thus, an image based on the signal supplied from the color imaging device 1 is displayed on the monitor device 8.

Further, the digital processor 4 includes a frame memory 56, a frame memory 57 as a spare of the frame memory 56, and the color image data R, G, B written in the frame memories 56, 57 or the frame memory 56. For reading image data of each color from the image data 57
And a controller 55.

The frame memory 56 includes, for example, a DRAM 56R for storing color image data R, a DRAM 56G for storing color image data G, and a D for storing color image data B.
And a DRAM 56B.
G and 56B can store, for example, color image data of 1280 × 960 pixels. Then, the frame memory 56
The color imaging data R, G, and B from the DRAMs 56R, 56G, and 56B are written or read based on the control of the DRAM controller 55.

The DRAM controller 55 includes an LUT 45
The color image data R, G, and B from R, 45G, and 45B are written into the frame memory 56, and the color image data from the frame memory are read. At this time, the color image data stored in the frame memory 56 is thinned out. do it,
Color imaging data of 640 × 480 pixels is read.

The frame memory 57 includes the frame memory 5
6, and is provided as a spare for the frame memory.

Further, the digital processor 4 has a DR
An averaging circuit 58 for removing an extra high frequency band from the color image data from the AM controller 55;
An interpolation circuit 59 that performs an interpolation process on each color imaging data from the M controller 55 and outputs luminance data Y
Image quality adjustment for increasing the sharpness of the image quality with respect to the luminance data Y from the interpolation circuit 59 and adjusting the contrast.
A contrast adjustment circuit 60, a matrix circuit 61,
A masking circuit 62 for widening the frequency bandwidth of each color imaging data from the matrix circuit 61, and an SCS as an interface for transmitting and receiving to and from the information processing device 5 and the like via a SCSI (Small Computer System Interface) bus.
I Protocol Controller (SPC: SCSI Protocol Contr
oller) 63.

The averaging circuit 58 removes unnecessary high frequency band components of the color image data R, G, and B in order to avoid the signal components in the high frequency band from folding back into the signal components in the low frequency band. The imaging data R, G, and B are supplied to the matrix circuit 61.

The interpolation circuit 59 interpolates the color image data to increase the resolution, for example, converts the interpolated color image data R, G, B into image data Y, U, V, and converts the luminance data Y. The color difference data U and V are supplied to a matrix circuit 61 while being supplied to an image quality adjustment / contrast adjustment circuit 60.
To supply.

The image quality adjustment / contrast adjustment circuit 60
For example, a contour signal is obtained from the luminance data Y by a high-pass filter, noise is removed from the contour signal by coring, the amplitude is adjusted, and this is added to the main signal to adjust the image quality. Also, an image quality adjustment / contrast adjustment circuit 6
0 changes the gain of the luminance data Y and appropriately changes the amplitude to adjust the contrast. The luminance data Y thus adjusted is supplied to the matrix circuit 61.

The matrix circuit 61 can output any of the supplied color image data R, G, B or the image data Y, U, V. For example, the color image data R, G, B
Is supplied to the masking circuit 62.

The masking circuit 62 widens the band of the supplied color image data R, G, and B to increase the degree of saturation so as to make the colors look brilliant, for example.
G and B are transmitted to the information processing device 5 or the like via the SPC 63.

The digital processor 4 is provided with the LU
A buffer memory 65 for writing level conversion data into T45R, 45G, 45B;
A buffer memory 66 for writing the level conversion data to 9G and 49B, a RAM 67 for storing the data of the LUTs 45 and 49, a ROM 68 in which a program for controlling the entire system is stored in advance, and a ROM 68 for storing the program. CPU 6 for executing programs
9 is provided.

In the imaging system configured as described above, an image corresponding to the subject is displayed on the monitor device 8 or the like. When the user presses the release button 9A of the remote controller 9 while looking at the monitor device 8, color imaging is performed. The data is stored in the frame memory 56. The color imaging data stored in the frame memory 56 is transferred to the information processing device 5 or the like via the SCSI bus, and the information processing device 5 can adjust the color balance. The printer 6 prints out a still image based on the color image data.

Specifically, as shown in FIG. 5, in this imaging system, in step S1, the user prepares a subject and focuses while watching a moving image displayed on the viewfinder 10, the monitor device 8, or the like. And adjust the angle of view, etc., and check the aperture value. Further, the user reads menu data from the ROM 68 in which a program for controlling the entire system is stored in advance and supplies the read menu data to the adders 50R, 50G, and 50B, thereby displaying the menu on the monitor device 8 or the like. While viewing the menu display (not shown) such as the camera sensitivity and exposure method
The photographing conditions are set by operating the buttons 9B and the like of the remote controller 9.

In this imaging system, in step S2, the user presses the release button 9A of the remote controller 9 and a release signal is supplied to the CPU 30 of the camera head 3 to image the subject. Further, the imaging signal obtained by the camera head 3 is
The digital processor 4 writes the color image data R, G, and B converted into digital signals in the digital processor 4 into the frame memory 56 via the DRAM controller 55.

Then, in the next step S3, the color image data R, G, B written in the frame memory 56.
From the matrix encoder 53 to the terminal 54
The imaging signal is supplied to the monitor device 8 via the. The user looks at the video projected on the monitor device 8 and transfers the video to the information processing device 5.

In the next step 4, when the user clicks, for example, the “Transfer” button 9 C on the remote controller 9 or the “Transfer” button 75 on the display screen of the information processing device 5, a transfer command signal is sent to the CPU 30 of the camera head 3. The transfer command signal is supplied to the CPU 69 of the digital processor 4 via the terminal 32. Under the control of the CPU 69, the DRAM controller 55 thins out and reads out the color imaging data stored in the frame memory 56. For example, the frame memory 56 includes the DRAM 5
Color image data of 1280 × 960 pixels is written in each of 6R, 56G, and 56B. These color image data R, G, B are converted into 6 by the DRAM controller 55.
It is thinned out by reading out 40 × 480 pixels.
The read color image data R, G, and B are output as they are from, for example, the matrix circuit 61 and transferred to the information processing device 5 via the masking circuit 62 and the SPC 63.

When the color image data R, G, B are transferred from the digital processor 4 to the information processing device 5, the information processing device 5 displays on the display 5A an image or the like based on the color image data R, G, B. Is displayed, and the automatic / manual selection setting wait state is set.

That is, in this imaging system, the color balance of the color image data R, G, B is adjusted based on the control of the color balance adjustment from the information processing device 5.

Here, the color balance adjustment by the information processing device 5 includes a standard subject correction for performing color balance adjustment at an arbitrary intermediate level from black to white, and a color balance adjustment at an arbitrary point of a video being shot. There is general subject correction.

In the case of the standard subject correction, a gray scale is imaged by the camera head 3. At this time, the display 5A of the information processing device 5 includes, as shown in FIG. 6, for example, a display unit 71 displaying a gray scale including eleven regions that gradually change from black to white, and an iris of the imaging lens 2. Iris registration unit 72, iris adjustment unit 73, and iris setting unit 74 in which a predetermined value of
An adjustment data transfer unit 75 for transferring adjustment data to the color imaging device 1 after performing color balance adjustment and the like;
A release section 76, a live / memory selection section 77 for switching between a live image and a memory image, a coordinate display section 78 for displaying, for example, the coordinates of the location of the display section 71 pointed by the mouse 5C in pixel units, A level display section 79 for displaying the level values of the signals R, G, and B; and an auto / manual for selecting whether to perform color balance adjustment automatically or manually.
The manual selection section 80 is displayed.

In the case of general subject correction, the display 5A is provided on the display 5A, for example, as shown in FIG.
Then, the image of the decimated subject is displayed. In addition,
The selection between the standard subject correction and the general subject correction can be performed by, for example, the remote controller 9 or the like.

Then, as shown in FIG. 6, for example, the user can designate a point on the screen displayed on the display section 71 of the display 5A by using, for example, the mouse 5C.

For example, in the case of the standard subject correction, when the user designates a gray level for performing gray balance adjustment by clicking an arbitrary place on the display section 71, the information processing apparatus 5
Indicates the respective signal level values of the color imaging signals R, G, and B at the designated position on the level display section 79 from 0h to FF.
The value is displayed up to h.

Similarly, in the case of general subject correction, when the user clicks an arbitrary place on the display unit 71 to specify a position where gray balance adjustment is to be performed, the information processing apparatus 5 causes the color imaging signal R at the specified position to be displayed. , G, and B are displayed on the level display section 79 as values from 0h to FFh.

In addition, when the user clicks on the mark of the iris registration section 72, the previously registered iris value is displayed. When the user clicks again on a desired one of the registered iris values, the information processing device 5 The data of the clicked iris value is transferred to the CPU of the camera head 3 described above.
30 to adjust the iris of the imaging lens 2. In addition, the user can select the iris adjustment unit 73
You can also adjust the iris by dragging the short crossbar of the right and left with the mouse.

As shown in the flowchart of FIG. 8, the information processing apparatus 5 allows the user to select the automatic / manual selection unit 80 in step S11 in the standby state.
When the button is clicked, the process proceeds to step S12, and it is determined whether or not the auto is selected.

The information processing apparatus 5 proceeds to step S13 to execute the automatic gray balance adjustment processing when the auto is selected, and proceeds to step S14 when the manual is selected, and waits for designation of a correction point. Becomes

The automatic adjustment of the gray balance in step S13 is performed by using the standard subject which provides a gray scale consisting of eleven areas that gradually change from black to white displayed on the display unit 71 shown in FIG. This is performed when shooting is performed, and is performed according to the flowchart shown in FIG.

Here, it is assumed that the gray area black area is area number A = 1, the white area is area number A = 11, and each intermediate gray area is area number A = 2-10.

Then, in the first step S21, the area number is initialized (A = 1), and in the next step S22, each color image data R,
GR and GB are calculated for G and B, and correction data is obtained in the next step S23 based on the calculation results.
This correction data is stored in association with the area number A. Corresponding to the area number A means that each color imaging signal R,
This corresponds to associating with the G and B signal level values.

Then, in the next step S24, it is determined whether or not the area number A has become "11". If A ≠ 11, the flow advances to step S25 to increment the area number A (A = A + 1). Then, the process returns to the step S22 to perform the processing of the next area. Correction data is sequentially obtained for each grayscale area, and if it is determined in step S24 that A = 11, the process proceeds to step S26, where LUT table data is generated based on the correction data for each grayscale area. Then, the process proceeds to step S16 in the flowchart of FIG.

In step S16, the information processing device 5
Sends a command to rewrite LUT table data to the CPU 69 of the digital processor 4 via the SPC 63. When the above-described table data is supplied from the information processing device 5 via the SPC 63, the CPU 69 of the digital processor 4 transmits the table data to the LUTs 45R, 45G, 45B via the buffer memory 65, for example.
To supply. The LUTs 45R, 45G, and 45B perform optimal color balance adjustment by rewriting the data in the table memories 452R, 452G, and 452B based on the data supplied from the buffer memory 65.

On the other hand, in step S14 when it is determined that the manual is set in step S12, the information processing apparatus 5
The correction portion is in a state of waiting for support, and operates after waiting for a user operation.

The process of adjusting the gray balance in steps S14 and S15 is performed by the display unit 71 shown in FIG.
Is performed based on the video displayed on the screen. First, step S
In 14, the user designates, by using the mouse 5A, an area in the video displayed on the display unit 71, where gray balance is to be performed. Then, the information processing device 5 generates color balance correction data based on the video of the designated area. Then, in step S16, the correction data is sent from the information processing device 5 to the digital processor 4. Then, through the buffer memory 65, the LUT4
5R, 45G, and 45B are stored in association with the designated area, that is, in association with the signal level of the video in the designated area.

The display 5A of the information processing device 5
For example, as shown in FIG. 10, a camera / monitor selecting unit 81 for selecting which LUT value to change on the camera side or the monitor device 8 side, and a table editor for displaying LUT data before adjustment in a graph. Unit 82 and the graph displayed on the table editor unit 82 are color imaging signals R,
A color signal selection unit 83 for selecting one of G and B, a reset unit 84 for resetting data being color-adjusted by the table editor unit 82 and the like, and a registration for registering color-corrected correction values Unit 85, a reversing unit 86 for reversing the negative / positive, a user table 87 displaying the current (before correction) LUT data, a calling unit 88 for calling a correction value registered by the user in the past, A screen including a return section 89 for returning to the screen can also be displayed.

In this case, for example, as shown in FIG. 11, the user drags and moves the two black points of the table editor unit 82 with the mouse, and thereby, for example, displays the color image data displayed on the color signal selection unit 83. The signal level of B can be adjusted. Therefore, the user looks at the display of the information processing device 5, for example,
It is possible to obtain color imaging data adjusted to a desired color balance.

When the user clicks the reversing unit 86, the CPU 69 of the imaging device reverses the characteristics of the LUTs 45R, 45G, 45B and LUTs 49R, 49G, 49B based on the control signal from the information processing device 5. That is, the CPU 69 normally inverts the characteristics of the LUT that rises to the right as shown in FIG. 12 to the characteristics of the LUT that descends to the right as shown in FIG. 13, thereby obtaining negative-positive converted color image data. be able to.

When the user sets, for example, the color imaging data B to a desired value and clicks on the registration unit 85, the information processing device 5 transmits the data of the set value to the digital processor 4. And LUT45R, 4
For 5G and 45B, the data in the LUT is rewritten, thereby changing the levels of the color imaging data R, G, and B supplied from the A / D converters 44R, 44G, and 44B to perform optimal color balance adjustment. Can be.

As described above, in this imaging system, it is possible to adjust the color balance even in the intermediate gray region between black and white, which could not be performed by the conventional white balance adjustment.

In the above-described imaging system, the color balance can be easily and easily adjusted by designating and changing an arbitrary point on the graph of the characteristic of the LUT displayed on the display of the information processing apparatus according to the user's preference. Can be adjusted.

Further, in the above-described imaging system, color imaging data to the monitor device can be corrected by the LUT separately from the main line, so that the overall color difference between the monitor device and the display of the information processing device is taken into consideration. This makes it possible to adjust the color balance.

In the above-described imaging system, by arranging a specific subject in advance and setting a pickup point, the color balance of the gray area from black to white can be automatically adjusted.

In this imaging system, the table data for controlling the level of each color image data for each color image signal can be adjusted as follows. This table data is generated by gray balance adjustment as described below.

The adjustment of the gray balance is shown in FIGS.
This is performed according to the flowchart shown in FIG.

First, as shown in FIG. 14, the user prepares white paper in step S31. And
In step S32, the aperture is opened, and in step S3
At 3, the gray balance adjustment is started. The processing for this gray balance adjustment is performed by the C
This is performed by the PU 30 or the CPU 69 of the digital processor 4 or the like.

In the gray balance adjustment, first, as shown in the flowchart of FIG.
The white level is set to a predetermined luminance level. The setting of the white level is performed according to the flowchart shown in FIG.

That is, in a state where the aperture is opened in step S32, it is first determined in step S51 whether or not the gray balance switch 9D of the remote controller 9 is pressed, and if the gray balance switch 9D is pressed, the next step is performed. Proceed to S52.

In steps S52 to S55, the imaging output of the white paper is determined by the gain of the gain control circuit 24, the aperture of the imaging lens 2 or the signal charge accumulation time of the CCD image sensor 21, that is, the electronic shutter. And adjusted so as to have a predetermined luminance level.

The above-mentioned predetermined luminance level corresponds to each color image pickup signal R, G, B for white paper with the aperture open.
Can be divided into 256 gradations,
When the signal level of the green imaging signal G corresponds to the 256th gradation, for example, the green imaging data G output from the gain control circuit 24 is set to be the 210th gradation.

That is, the white paper is imaged by the camera head 3 with the aperture open. The imaging output of the CCD image sensor 21 of the camera head 3 is a CDS
The signal is supplied to a gain control circuit 24 via a circuit 22 and a preamplifier circuit 23. The green imaging data G output from the gain control circuit 24 is supplied to the CPU 30 as a luminance level.

Then, in step S52, the CPU 30
Determines whether the brightness level of the image output of the white paper is lower than a predetermined brightness level. If the luminance level of the imaging output is smaller than the predetermined luminance level, the CPU 30 proceeds to step S53, increases the gain of the gain control circuit 24 so as to increase the luminance level, and returns to step S52. The luminance level of the image pickup output is repeatedly determined.

If it is determined in step S52 that the brightness level of the imaging output is not lower than the predetermined brightness level, the process proceeds to step S54.

In step S54, the CPU 30 determines whether or not the luminance level of the white paper image pickup output is higher than a predetermined luminance level. If the luminance level of the imaging output is higher than the predetermined luminance level, the process proceeds to step S55 so as to reduce the aperture of the imaging lens 2 or the signal charge accumulation time of the CCD image sensor 21, that is, the electronic shutter. To control the step S5
Returning to step 2, the luminance level of the image pickup output is repeatedly determined.

The electronic shutter is controlled by the CPU 30 by the timing generator 34 and the CCD driver 3.
5, the signal charge accumulation time of the CCD image sensor 21 is changed.

When the white level is set to the predetermined luminance level in step S41 in the flowchart of FIG. 15, the CPU 30 of the camera head 3 proceeds to step S42 and sends the image data R, G, An instruction is issued to load B into the frame memory 56. The image data R, G, and B once taken into the frame memory 56 are read from the frame memory 56 and taken into the information processing device 5.

In step S43, the information processing device 5 creates data for color balance correction. Here, correction amounts R ′, R ′, G ′, and B ′ are based on the color image data G in the color image data R, G, B.
B 'is calculated. R ′ and B ′ are R ′ = R−
G, B '= BG. The correction amount data R ', B' calculated here and the color image data R, G, B
In step S44, the LUT 45R, 45G, 45B
The table data in the table memories 452R, 452G, and 452B is rewritten.

That is, in the digital processor 4, when the correction data R 'and B are supplied from the information processing device 5 to the SPC 63, the CPU 69 controls the table memory 452R of the LUTs 45R, 45G and 45B via the buffer memory 65. Writing of table data is performed to 452G and 452B.

Further, in step S45, it is determined whether or not the color imaging data R, G, B taken into the information processing apparatus 5 via the frame memory 56 has a black luminance level. If it is determined in step S45 that the brightness level is not the black luminance level, step S46 is performed.
Then, the exposure amount control is performed. In this step S46, a command is sent from the information processing device 5 to the CPU 30 of the camera head 3, and the CPU 30 controls the charge accumulation time of the CCD image sensor 21 or the aperture value of the imaging lens 2. For this exposure amount control, a method of controlling the signal charge accumulation time with a fixed aperture and a method of controlling the aperture with a constant signal charge accumulation time can be selected.
The exposure amount control of the method selected by the user is executed.

In the exposure amount control performed under the constant aperture, the signal charge accumulation time of the CCD image sensor 21 is changed to reduce the effective exposure amount. In the exposure amount control performed while keeping the signal charge accumulation time of the electronic shutter constant, the aperture value of the imaging lens 2 is changed to reduce the exposure amount during shooting.

After the exposure amount is reduced, step S4 is performed again.
In 3, the correction amounts R ', B' are calculated based on the color image data R, G, B. The color image data R, G,
B and the correction amounts R ′ and B ′ are stored in the LUT 45 via the buffer memory 69 from the information processing device 5 in step S44.
R, 45G, 45B table memories 452R, 452
G, 452B.

The processing from step S41 to step S46 in the flowchart of FIG.
5 until the luminance level reaches the black level. Therefore, adjustment data at each gray level can be obtained. Then, when the luminance level becomes the black level, the creation of the table data by the gray balance adjustment in step S33 shown in FIG. 14 ends.

The gray level control from the white level to the black level, which is performed in the gray balance adjustment, can be continuously changed by controlling the signal charge accumulation time of the aperture or the electronic shutter to be changed at a certain fixed value. Is possible. Thus, a desired number of samples can be obtained between the white level and the black level.

The table data on which the gray balance has been adjusted in this manner is used as a color image signal of the subject, that is, the A / D converters 44R and 44R, which are input thereafter.
G, image data R, G,
For B, appropriate color balance adjustment can be performed.
As a result, the color image data R, G, B of the camera on which the color balance is adjusted, that is, the main line system, is output to each output unit via a D / A converter or the like.

As described above, in this imaging system, the color balance can be adjusted even in an intermediate gray area between black and white, which cannot be performed by the conventional white balance adjustment.

In the above-described imaging system, the color balance can be easily and easily adjusted by designating and changing an arbitrary point of the image displayed on the display of the information processing apparatus according to the user's preference. Can be.

In the above-described imaging system, by arranging a specific subject in advance and setting a pickup point, the color balance of a gray area from black to white can be automatically adjusted.

[0104]

According to the present invention, a subject is imaged to generate a color image signal composed of a plurality of color signals, and level balance control data is generated based on the correlation between the signal levels of the plurality of color signals. In each exposure amount adjusted by the exposure adjusting unit, the level balance control data is stored in association with the signal levels of the plurality of color signals at the respective exposure amounts, and based on the signal levels of the color signals. Read the stored level balance control data, and based on the read level balance control data,
By controlling the signal levels of the respective color signals, it is possible to adjust the color balance even in a gray area intermediate between black and white, which cannot be performed by the conventional white balance adjustment.

Further, according to the present invention, a subject is imaged to generate a color imaging signal composed of a plurality of color signals, and a portion representing a plurality of predetermined region images on the screen represented by the color imaging signal is generated. Color imaging signals are sequentially extracted, and based on the correlation between the signal levels of the plurality of color signals included in each of the predetermined areas, level balance control data is generated, and the level balance control data is generated in each of the predetermined areas. A plurality of color signals are stored in association with signal levels, and the stored level balance control data is read out based on the signal levels of the color signals, and the signal levels of the color signals are read out based on the read level balance control data. By performing the control, the color balance adjustment in all the gray regions from black to white can be automatically performed.

Further, according to the present invention, a subject is imaged to generate a color imaging signal composed of a plurality of color signals, an image based on the color imaging signal is displayed, and a desired area in the displayed image is displayed. And generating level balance control data based on the correlation between the signal levels of the plurality of color signals constituting the color imaging signal corresponding to the designated area. The area is stored in association with the signal levels of the plurality of color signals in the area, and based on the signal level of each color signal, the stored level balance control data is read out, and based on the read level balance control data, By controlling the signal level, the color balance in all gray areas from black to white can be adjusted by a simple operation.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a schematic configuration of an imaging system to which the present invention has been applied.

FIG. 2 is a block diagram illustrating a specific configuration of a camera head of a color imaging device in the imaging system.

FIG. 3 is a block diagram showing a specific configuration of a digital processor of the color imaging device.

FIG. 4 is a block diagram showing a configuration of an LUT provided in the digital processor.

FIG. 5 is a flowchart illustrating a color balance adjustment method in the imaging system.

FIG. 6 is a diagram illustrating display contents on a display of the information processing apparatus in the imaging system.

FIG. 7 is a diagram illustrating display contents on a display of the information processing apparatus.

FIG. 8 is a flowchart showing a procedure for adjusting a color balance in the imaging system.

FIG. 9 is a flowchart showing a procedure of automatic color balance adjustment in the imaging system.

FIG. 10 is a diagram illustrating display contents of a display of the information processing apparatus.

FIG. 11 is a diagram illustrating display contents of a display of the information processing apparatus.

FIG. 12 is a diagram illustrating characteristics of a normal LUT in the imaging system.

FIG. 13 is a diagram for explaining characteristics of the LUT when the negative / positive is reversed in the imaging system.

FIG. 14 is a flowchart illustrating another method of adjusting the color balance in the imaging system.

FIG. 15 is a flowchart illustrating a procedure for creating color balance correction data.

FIG. 16 is a flowchart illustrating a procedure for setting a white luminance level.

[Explanation of symbols]

1 color imaging device, 3 camera head, 4 digital processor, 5 information processing device, 8 monitor device, 2
1 CCD image sensor, 45R, 45G, 45B
LUT, 49R, 49G, 49B LUT, 69 CP
U

Claims (11)

[Claims] An imaging unit configured to image a subject and generate a color imaging signal including a plurality of color signals, based on a correlation between signal levels of the plurality of color signals;
Level balance control data generation means for generating level balance control data; exposure amount adjustment means for adjusting the exposure amount of the imaging means; and for each exposure amount adjusted by the exposure adjustment means, the level balance control data generation means Storage means for storing the level balance control data generated by the plurality of color signals at the respective exposure amounts in association with the signal levels; and, based on the signal levels of the respective color signals, the respective color signals from the storage means. A color image pickup apparatus comprising: level balance control means for reading out corresponding level balance control data and controlling the signal level of each color signal. 2. The level balance control data generating means generates the level balance control data in an adjustment mode, and the level balance control means controls a signal level of each color signal at least in an imaging mode. The color imaging device according to claim 1. 3. In the adjustment mode, the exposure amount adjustment unit adjusts the exposure amount of the imaging unit to a predetermined exposure amount before the level balance control data generation unit generates the level balance control data. 3. The color imaging device according to claim 2, wherein: 4. An image of a subject is generated to generate a color image signal including a plurality of color signals, and based on a correlation between signal levels of the plurality of color signals,
Generating level balance control data, storing the level balance control data in association with the signal levels of the plurality of color signals at each of the exposure amounts for each of the exposure amounts adjusted by the exposure adjusting means, A color imaging method comprising: reading out stored level balance control data based on the signal levels of the color signals; and controlling the signal levels of the respective color signals based on the read level balance control data. 5. An image pickup means for picking up an image of a subject to generate a color image pickup signal composed of a plurality of color signals, and a color image pickup signal of a portion representing an image of a plurality of predetermined areas in a screen represented by the color image pickup signal. A predetermined area extracting means for sequentially extracting a plurality of color signals; a level balance control data generating means for generating level balance control data based on a correlation between signal levels of a plurality of color signals included in each of the predetermined areas; Storage means for storing data in association with the signal levels of the plurality of color signals in each of the predetermined areas; and level balance control data corresponding to each color signal from the storage means based on the signal level of each color signal. A color image pickup apparatus comprising: a level balance control unit for reading and controlling the signal level of each color signal. 6. The level balance control data generating means generates the level balance control data in an adjustment mode, and the level balance control means controls a signal level of each color signal at least in an imaging mode. The color imaging device according to claim 5, wherein 7. The color image pickup apparatus according to claim 5, wherein said toned subject has different brightness for each determined area. 8. An image of a subject is generated to generate a color imaging signal composed of a plurality of color signals, and a color imaging signal of a portion representing an image of a plurality of predetermined areas in a screen represented by the color imaging signal is sequentially extracted. And generating level balance control data based on the correlation between the signal levels of the plurality of color signals included in each of the predetermined areas, and converting the level balance control data into the signals of the plurality of color signals in each of the predetermined areas. And reading the stored level balance control data based on the signal level of each color signal, and controlling the signal level of each color signal based on the read level balance control data. Color imaging method. 9. An image pickup means for picking up an image of a subject to generate a color image pickup signal composed of a plurality of color signals; a display means for displaying an image based on the color image pickup signal; Area designating means for designating a desired area; and level balance control data based on a correlation between signal levels of a plurality of color signals constituting the color imaging signal corresponding to the area designated by the area designating means. Level balance control data generating means for generating; storage means for storing the level balance control data in association with signal levels of the plurality of color signals in an area designated by the area designating means; and a signal for each color signal Based on the level, read out the level balance control data corresponding to each color signal from the storage means, and The color image pickup apparatus is characterized in that a level balance control means for controlling the issue level. 10. The level balance control data generating means generates the level balance control data in an adjustment mode, and the level balance control means controls a signal level of each color signal at least in an imaging mode. The color imaging device according to claim 9, wherein 11. An image of a subject is generated to generate a color imaging signal composed of a plurality of color signals, an image based on the color imaging signal is displayed, and a desired area of the displayed image is designated, and the designated area is designated. Generating level balance control data based on the correlation between the signal levels of the plurality of color signals constituting the color imaging signal corresponding to the region, and converting the level balance control data into the plurality of colors in each of the predetermined regions. Storing the signal in association with the signal level of the signal; reading out the level balance control data after storing based on the signal level of each color signal; and controlling the signal level of each color signal based on the read level balance control data. A color imaging method characterized by the above-mentioned.