JP2002095020A - Image adjusting system, imaging device and image- adjusting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce work required for adjusting an image, while simplifying the construction in an image adjusting system. SOLUTION: A test chart, where a plurality of adjusting patterns are arranged in accordance with a plurality of adjusting items is imaging. Image areas corresponding to the adjusting items in the image are sequentially extracted. Reference signals becoming reference when the image is adjusted according to the adjusting items are detected from the extracted image areas and the images with respect to the adjusting items are adjusted. Thus, it is not necessary to move the imaging device which is object of adjustment or to exchange the test chart, and the work required for adjusting the image can be reduced by that amount, while its constitution is simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image adjustment system, an image pickup apparatus, and an image adjustment method, and is suitably applied to, for example, adjustment of an image picked up by a video camera in a video camera production process. is there.

[0002]

2. Description of the Related Art Conventionally, when adjusting an image captured by a video camera in a video camera production process, an EIAJ (Electric Industries Association of J.
apan: General-purpose test charts and general-purpose optical filters established by the Japan Electronic Machinery Manufacturers Association) are used.

As the general-purpose test chart, for example, a gray scale chart for adjusting a reference light amount and a color bar chart for adjusting color reproducibility are prepared. As a general-purpose optical filter, for example, a color of a light source is used. A color temperature conversion filter for converting the temperature and an ND (Neutral Density Filter) filter for limiting the amount of incident light are provided.

There are a plurality of adjustment items for adjusting an image picked up by a video camera, such as light intensity, white balance, and color reproducibility. Therefore, as an image adjustment method for performing image adjustment of a video camera, a light source on which a different test chart or optical filter is arranged for each adjustment item is previously installed at a predetermined position, and the light source is installed at a place where the light source is installed. A method of performing image adjustment while sequentially moving a video camera, or a method of performing image adjustment while exchanging a test chart or an optical filter with the same light source is employed.

[0005]

By the way, in the method of adjusting the image while moving the video camera to the place where the light source is installed, it is necessary to secure an installation place for installing the light source for each adjustment item. In addition, the video camera must be moved every time the adjustment item changes, and the angle of view must be adjusted each time. Therefore, there is a problem that the configuration becomes large and the work related to image processing becomes complicated.

In the method of adjusting the image while replacing the test chart and the optical filter with the same light source, it is necessary to automate the replacement of the test chart and the optical filter in order to reduce the adjustment process. However, since the test chart and the optical filter are made of glass, there is a problem that the equipment for automating the replacement of the test chart and the optical filter cannot be avoided.

The present invention has been made in view of the above points, and proposes an image adjustment system, an image pickup apparatus, and an image adjustment method capable of reducing the work required for image adjustment with a simpler configuration than in the past. It is assumed that.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a test chart in which a plurality of adjustment patterns are arranged so as to correspond to a plurality of adjustment items is picked up, and the image of the picked-up image is taken. The image area of the adjustment pattern corresponding to each adjustment item is sequentially extracted, and a reference signal serving as a reference when performing image adjustment according to the adjustment item is detected from each of the extracted image areas, and a reference signal for each adjustment item is detected. By performing the image adjustment, it is not necessary to move the imaging device to be adjusted for each adjustment item and to exchange test charts.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a video camera as a whole, and transmitted light L1 emitted from a light source 2 and transmitted through a test chart 3 is incident on a video camera 4 to be adjusted.

Here, as shown in FIG. 2, the test chart 3 includes a gray scale chart for setting a reference light amount as a reference for performing each adjustment, and a color bar chart for adjusting color reproducibility. , And three types of color temperature conversion filters for converting the color temperature of the light source.

That is, in the test chart 3, a gray scale chart area 3X that functions as a gray scale chart, a color bar chart area 3Y that functions as a color bar chart, and a color temperature conversion filter area 3Z that functions as a color temperature conversion filter. Are arranged at predetermined positions on the same plane.

Specifically, in the gray scale chart area 3X, color patches having different transmittances are arranged from i to ix in descending order of transmittance. In the color bar chart area 3Y, white (W), yellow (Ye), cyan (Cy), green (G), magenta (Mg), red (R), and blue (B) color chips are respectively arranged. ing.

Further, in the color temperature conversion filter area 3Z,
Three kinds of color temperature conversion filters A, B, and C, which are correlated so as to have predetermined three kinds of color temperatures with respect to the color temperature of the light source, are arranged from A to C in ascending order of color temperature. I have.

The test chart 3 is imaged by the video camera 4 to be adjusted. That is, returning to FIG. 1, the transmitted light L1 transmitted through the test chart 3 is incident on the video camera 4. And this video camera 4
Is transmitted through a lens 10 to a stop mechanism 11, and the amount of light is adjusted by the stop mechanism 11, and then a solid-state image pickup device (CCD: Charge Coupler).
ed Device) 12. The CCD 12 photoelectrically converts the received transmitted light L1 into an electric signal, and sends the resulting image signal S1 to the signal processing circuit 13.

The signal processing circuit 13 performs predetermined image processing on the image signal S1 while sending the supplied image signal S1 to the detection unit 14 as it is, thereby obtaining an NTSC signal.
(National Television System) system, which is converted into a television signal S2, transmitted to the monitor 15, and displayed on the display screen.

When the adjuster operates the input unit 21 to input position information indicating the position of each area arranged on the test chart 3, the adjustment control unit 20 receives the input. The position information is stored in an internal memory (not shown).

As shown in Procedure 1 in FIGS. 3A and 3B, the adjustment control unit 20 first sets a reference light amount that is used as a reference when performing each adjustment. That is, the adjustment control unit 20 detects the detection control signal S5A for setting the reference light amount based on the position information stored in the memory (not shown).
Is generated and sent to the detection unit 14.

As shown in FIG. 4, the detector 14 switches the image signal S1 supplied from the signal processing circuit 13 to a switch SW.
While the detection control signal S5A supplied from the adjustment control unit 20 is supplied to the detection range signal generation unit 25 and the selector S
Input to L.

The detection range signal generation unit 25 includes a switch SW
And the extraction means, and by switching the connection state of the switch SW based on the detection control signal S5A supplied from the adjustment control unit 20, the brightest area of the gray scale chart area 3X in the captured test chart 3 Has been made to detect.

That is, the detection range signal generator 25 supplies an image consisting of the brightest area of the gray scale chart area 3X, that is, the area of the color chart i having the highest transmittance among the images of the test chart 3 indicated by the image signal S1. Is turned on, the switch SW is turned on. On the other hand, when an image other than the image consisting of the brightest area of the gray scale chart area 3X is supplied from the test chart 3, the switch SW is turned off. Switch to state.

At this time, the selector SL is controlled by the adjustment control unit 20.
The connection state is switched to the first input terminal side based on the detection control signal S5A supplied from the
6A is selected.

In this way, the gray scale chart area 3 of the test chart 3 is stored in the luminance signal detecting section 26A.
An image signal S consisting of only the image in the brightest area of X
6A is supplied from the switch SW, and the luminance signal detecting unit 26A detects the luminance signal S7A from the image signal S6A and sends it to the adjustment control unit 20 via the selector SL.

The adjustment control section 20 generates exposure drive information S10 for driving the aperture mechanism section 11 so that the luminance signal S7A supplied from the detection section 14 matches a predetermined value. This is sent to the exposure drive unit 30.
The exposure drive unit 30 generates an exposure drive signal S11 according to the supplied exposure drive information S10, and outputs this to the aperture mechanism unit 1.
Send to 1. The aperture mechanism 11 receives the exposure drive signal S
Exposure control is realized by adjusting the aperture value and adjusting the light amount based on the reference numeral 11.

Next, as shown in Procedure 2 in FIGS. 3A and 3B, the adjustment controller 20 performs an automatic white balance adjustment for adjusting a change in color tone due to a light source with reference to white. That is, the adjustment control unit 20 generates a detection control signal S5B for performing the automatic white balance adjustment based on the position information stored in the memory (not shown), and sends it to the detection unit 14.

As shown in FIG. 4, the detector 14 switches the image signal S1 supplied from the signal processing circuit 13 to a switch SW.
While the detection control signal S5B supplied from the adjustment control unit 20 is supplied to the detection range signal generation unit 25 and the selector S
Input to L.

The detection range signal generator 25 is provided with the adjustment controller 2
By switching the connection state of the switch SW based on the detection control signal S5B supplied from 0, the color temperature conversion filter C having the highest color temperature in the color temperature conversion filter area 3Z of the captured test chart 3 is detected. It has been made like that.

That is, the detection range signal generator 25 outputs the image corresponding to the color temperature conversion filter C having the highest color temperature, which is located in the color temperature conversion filter area 3Z, of the image of the test chart 3 indicated by the image signal S1. Is supplied, an image other than the image corresponding to the color temperature conversion filter C in the color temperature conversion filter area 3Z is supplied from the image of the test chart 3 while the switch SW is turned on. When the switch is ON, the switch SW is turned off.

At this time, the selector SL is controlled by the adjustment control unit 20.
The connection state is switched to the second input terminal side based on the detection control signal S5B supplied from the
6B is selected.

As described above, the image signal S6B composed of only the image corresponding to the color temperature conversion filter C in the color temperature conversion filter area 3Z of the test chart 3 is supplied to the primary color signal detection section 26B from the switch SW. the primary color signal detecting section 26B detects a primary color signals S7B ₁ from the image signal S6B, and sends to the adjustment control unit 20 which via a selector SL.

The adjustment control section 20 stores the primary color signals S7B ₁ supplied from the detection unit 14 in an internal memory (not shown). Further, the adjustment controller 20 controls the color temperature conversion filters A and B arranged in the color temperature conversion filter area 3Z.
The primary color signals 7B ₂ and 7B ₃ from each image corresponding to respectively detected by the detection unit 14, stores the primary color signals S7B ₂ and S7B ₃ which is the detected in memory. Then, the adjustment controller 20 controls the primary color signal S7B stored in the memory.
Using the _{1 ~S7B 3} as a correction value of the primary color signals in the automatic white balance control operation.

Further, the adjustment control section 20 performs color reproducibility adjustment as shown in Procedure 3 in FIGS. 3A and 3B. That is, the adjustment control unit 20 generates a detection control signal S5C for performing color reproducibility adjustment based on the position information stored in the memory (not shown), and sends it to the detection unit 14.

As shown in FIG. 4, the detector 14 switches the image signal S1 supplied from the signal processing circuit 13 to a switch SW.
While the detection control signal S5C supplied from the adjustment control unit 20 is supplied to the detection range signal generation unit 25 and the selector S
Input to L.

The detection range signal generator 25 is provided with the adjustment controller 2
By switching the connection state of the switch SW based on the detection control signal S5C supplied from 0, the color bar chart area 3Y in the imaged test chart 3 is obtained.
Is detected in the white (W) area.

That is, the detection range signal generator 25 switches the switch SW when the image of the white (W) area of the color bar chart area 3Y is supplied from the image of the test chart 3 indicated by the image signal S1. On the other hand, when an image other than the image of the white (W) area of the color bar chart area 3Y is supplied from the test chart 3 image, the switch SW is switched to the off state.

At this time, the selector SL is controlled by the adjustment control unit 20.
The connection state is switched to the third input terminal side based on the detection control signal S5C supplied from the
6C is selected.

As described above, the color difference signal detecting section 26C is supplied with the image signal S6C composed of only the image of the white (W) area of the color bar chart area 3Y of the test chart 3 from the switch SW, and the color difference signal The detection unit 26C converts the color difference signal S7C ₁ from the image signal S6C.
Is detected, and is sent to the adjustment control unit 20 via the selector SL.
To send to.

The adjustment control unit 20, as color difference signals S7C ₁ supplied from the detecting unit 14 matches the predetermined value determined in advance, for adjusting the color difference gain is a parameter in the signal processing circuit 13 By generating a color difference gain adjustment signal S15 and sending it to the signal processing circuit 13, adjustment of color reproducibility is realized.

Further, the adjustment controller 20 controls the yellow (Ye), cyan (Cy), green (G), magenta (Mg), red (R) and blue (B) arranged in the color bar chart area 3Y. It is sequentially detected by the detector 14 the color difference signals S7C ₂ ~S7C ₇ from the image obtained from the color chart, the detected color difference signals S7C ₂ ~S7C
₇ , the color difference gain of the signal processing circuit 13 is adjusted.

As described above, the adjustment controller 2 of the video camera 4
0 indicates that when the video camera 4 is set at a predetermined position of the image adjustment apparatus 1, the image adjustment processing procedure RT1 shown in FIG.
Execute That is, when entering the image adjustment processing procedure RT1, the adjustment control unit 20 proceeds to step SP1 and detects the detection range for setting the reference light amount from the image of the test chart 3 based on the position information regarding the test chart 3. Set to 14.

Further, the adjustment controller 20 determines in step SP2
Then, the detection unit 14 is caused to select the luminance signal detection unit 26A for setting the reference light amount, thereby detecting the luminance signal S7A corresponding to the detection range. Then, the adjustment controller 20 proceeds to step SP3 to control the exposure driver 30 so that the luminance signal S7A detected by the detector 14 matches a predetermined value, and sets a reference light amount.

Next, the adjustment controller 20 proceeds to step SP4
Then, the detection unit 14 is caused to set the detection range for the automatic white balance adjustment from the image of the test chart 3 based on the positional information on the test chart 3.

Further, the adjustment controller 20 determines in step SP5
Then, the primary color signal detection unit 26B is selected for the automatic white balance adjustment by the detection unit 14, thereby detecting the primary color signal S7B corresponding to the detection range.
Then, the adjustment control unit 20 proceeds to the subsequent step SP6, and converts the primary color signal S7B detected by the detection unit 14 into
The correction value of the primary color signal during the automatic white balance adjustment control operation is stored in an internal memory, and the automatic white balance adjustment is performed.

Next, the adjustment controller 20 proceeds to step SP7.
Then, the detection unit 14 is caused to set the detection range for color reproducibility from the image of the test chart 3 based on the positional information on the test chart 3.

Further, the adjustment controller 20 determines in step SP8
Then, the detection unit 14 is caused to select the color difference signal detection unit 26C for color reproducibility, thereby detecting the color difference signal S7C corresponding to the detection range. And the adjustment controller 20
Proceeds to step SP9, adjusts the color difference gain of the signal processing circuit 13 so that the color difference signal S7C detected by the detection unit 14 matches a predetermined value, and adjusts color reproducibility. The process moves to SP10 and ends the processing procedure.

In the above configuration, the image adjusting device 1
Adopts a reference light amount, an auto white balance, and color reproducibility as adjustment items for adjusting an image captured by the video camera 4. In this case, in the image adjustment device 1,
A gray scale chart area 3X for setting a reference light quantity, a color bar chart area 3Y for adjusting color reproducibility, and a color temperature conversion filter area 3Z for adjusting auto white balance are provided on a predetermined plane. Test charts 3 arranged at respective positions are used.

The adjustment control unit 20 generates a detection control signal S5A for setting a reference light amount based on the position information indicating the position of each of the regions 3X to 3Z arranged on the test chart 3, and sends the detection control signal S5A to the detection unit 14. Send out. The detection range signal generation unit 25 of the detection unit 14 switches the connection state of the switch SW based on the detection control signal S5A, thereby selecting from the image signal S1 obtained by imaging the test chart 3
The image signal S6A corresponding to the range of the gray scale chart area 3X is detected.

At this time, the selector SL of the detecting section 14 switches the connection state based on the detection control signal S5A to select the luminance signal detecting section 26A, and the selected luminance signal detecting section 26A changes the image signal S6A to the selected luminance signal. Luminance signal S
7A is detected. Then, the adjustment control unit 20 controls exposure based on the detected luminance signal S7A, and sets a reference light amount.

Hereinafter, similarly, the detecting section 14 detects the color temperature conversion filter area 3Z and the color bar chart 3Y from the image signal S1 obtained by imaging the test chart 3.
Are sequentially detected, and a primary color signal S7B and a color difference signal S7C are sequentially detected from the detected image signals S6B and S6C. Then, the adjustment controller 20 outputs the detected primary color signal S7B
, And the color reproducibility is adjusted based on the color difference signal S7C.

As described above, in the image adjustment apparatus 1, it is not necessary to secure a place where a light source or the like is installed for each adjustment item as in the related art, and the video camera to be adjusted is moved every time the adjustment item changes. Since it is not necessary to replace the test chart and the optical filter, it is possible to reduce the work required for image adjustment while simplifying the configuration.

According to the above configuration, the test chart 3 is constituted by the gray scale chart, the color bar chart, and the color temperature conversion filter.
Are sequentially extracted from the image obtained by capturing the image, and a signal serving as a reference when performing image adjustment is sequentially detected from the extracted image to perform image adjustment for each adjustment item. Accordingly, there is no need to move the video camera 3 to be adjusted or to exchange the test chart and the optical filter. Therefore, it is possible to reduce the work required for image adjustment while simplifying the configuration.

In the above embodiment, the case where the exposure control is realized by adjusting the aperture value of the aperture mechanism 11 has been described. However, the present invention is not limited to this.
For example, controlling the exposure time (shutter speed) of the CCD 12, controlling the gain of the amplifier in the signal processing circuit 13, and controlling the image signal S output from the CCD 12
Exposure may be controlled by amplifying 1.

In the above-described embodiment, adjustment items for adjusting an image picked up by the video camera 4 include:
Although the case where the reference light amount, the auto white balance and the color reproducibility are adopted has been described, the present invention is not limited to this, and other various adjustment items may be adopted.

In the above-described embodiment, a case has been described where the test chart 3 as an object to be imaged is configured by combining a gray scale chart, a color bar chart, and a color temperature conversion filter. The present invention is not limited to this, and a test chart may be configured by combining various adjustment patterns according to adjustment items.

Further, in the above-described embodiment, the case where the image picked up by the video camera 4 is adjusted has been described. However, the present invention is not limited to this, and various other image pickup devices such as a still camera may be used. The captured image may be adjusted.

[0056]

As described above, according to the present invention, a test chart in which a plurality of adjustment patterns are respectively arranged so as to correspond to a plurality of adjustment items is picked up, and each adjustment item in the picked-up image is assigned to each adjustment item. Sequentially extracting image areas of the corresponding adjustment pattern, detecting a reference signal as a reference when performing image adjustment according to the adjustment item from each of the extracted image areas, and performing image adjustment for each adjustment item. Accordingly, it is not necessary to move the imaging device to be adjusted for each adjustment item or to exchange test charts, and accordingly, the work required for image adjustment can be reduced while simplifying the configuration of the image adjustment system.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating an embodiment of an image adjustment device according to the present invention.

FIG. 2 is a schematic diagram illustrating a configuration of a test chart.

FIG. 3 is a table showing adjustment contents in each adjustment item.

FIG. 4 is a block diagram illustrating a configuration of a detection unit.

FIG. 5 is a flowchart illustrating an image adjustment processing procedure.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Image adjustment apparatus, 2 ... Light source, 3 ... Test chart, 3X ... Gray scale chart, 3Y ... Color bar chart, 3Z ... Color temperature conversion filter, 4 ... Video camera, 11 ... Aperture Mechanism part, 12 ... CCD, 1
3 ... signal processing circuit, 14 ... detector, 20 ... adjustment controller, 25 ... detection range signal generator, 26A ... luminance signal detector, 26B ... primary color signal detector, 26C ... color difference signal Detecting unit 30, exposure driving unit.

Claims (6)

[Claims] An image adjustment system for adjusting an image captured by an imaging device as an adjustment target for a plurality of adjustment items, wherein the image is adjusted for each of the adjustment items so as to correspond to the plurality of adjustment items. A test chart in which a plurality of adjustment patterns are arranged, and an imaging device for imaging the test chart, wherein the imaging device has a position of each of the adjustment patterns arranged on the test chart. Extracting means for sequentially extracting an image area of the adjustment pattern corresponding to each of the adjustment items from the image based on the position information indicating the plurality of adjustment items; and A plurality of detection means for detecting a reference signal as a reference when performing image adjustment according to the adjustment item from each image area. Image adjustment system characterized by comprising and. 2. The image adjustment system according to claim 1, wherein the test chart includes a gray scale chart, a color bar chart, and a color temperature conversion filter. 3. An imaging apparatus for adjusting a captured image for a plurality of adjustment items, wherein a plurality of adjustment patterns for adjusting the image for each of the adjustment items are provided so as to correspond to the plurality of adjustment items. Imaging means for imaging the test charts respectively arranged, and the adjustment patterns corresponding to the respective adjustment items in the image based on position information indicating the positions of the respective adjustment patterns arranged on the test charts Extracting means for sequentially extracting the image areas, and a reference signal which is provided corresponding to the plurality of adjustment items and serves as a reference when performing image adjustment in accordance with the adjustment items from the extracted image areas. An imaging apparatus, comprising: a plurality of detection means for detecting respective ones. 4. The image pickup apparatus according to claim 3, wherein the test chart includes a gray scale chart, a color bar chart, and a color temperature conversion filter. 5. An image adjustment method for adjusting an image picked up by an image pickup apparatus as an adjustment target for a plurality of adjustment items, wherein the image is adjusted for each of the adjustment items so as to correspond to the plurality of adjustment items. A plurality of adjustment patterns for performing the adjustment are respectively captured by the imaging device, and based on position information indicating the position of each of the adjustment patterns arranged on the test chart, An image area of the adjustment pattern corresponding to each adjustment item is sequentially extracted, and a reference signal serving as a reference when performing image adjustment according to the adjustment item is detected from each of the extracted image areas. Image adjustment method. 6. The image adjustment method according to claim 5, wherein the test chart includes a gray scale chart, a color bar chart, and a color temperature conversion filter.