JPS62117489A - Color television camera device - Google Patents

Abstract

PURPOSE:To automatically adjust the tone setting of respective cameras by using a green color video signal of a reference camera as a reference value, inputting to the camera to be controlled, picking up the image of the same chart by the respective cameras, and adjusting a color reproductivity. CONSTITUTION:The green color video signal from the reference camera is inputted to a reference signal input terminal 7 of the respective cameras to be controlled. The respective cameras to be controlled pick up the image of a specific chart including a white, a grey and a black component under the same condition, and input video signal outputs 12R, 12G, 12B together with the green color video signal 13 of the reference camera to a multiplexer 14. The multiplexer selects the input signal according to a control mode through the instruction from an microprocessor 15 and inputs to a differential amplifier 16. The output signal of the amplifier 16 has a specific part sampled by a sample pulse 18 and the quantity of control for making a video difference signal zero is calculated in the microprocessor 15.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a device for matching the tone (color reproducibility) of a plurality of cameras in a color television camera having an automatic adjustment function.

(Prior art and its problems) High-grade three-tube (three-plate) color television cameras for broadcasting purposes generally have a built-in microprocessor and an automatic camera adjustment function.

Among the automatic adjustment functions, the color balance system adjustment, which depends on the color reproduction characteristics of the camera, is carried out with the built-in lens or external special chart imaging l~, ]) in each camera.

2) A method of adjusting red and blue video signal values from 1 to 1 based on a green video signal value, and 2) After adjusting the green video signal value to a reference value for each factor occurring in the camera,
The adjustment method described in 1) above is used, but in the case of 1), there is a difference in color reproducibility of the green video signal between cameras, and 2)
In this case, the tones between cameras do not match even after automatic adjustment due to differences in reference values that occur between each camera.

Moreover, when one color reproducibility (for example, gamma, etc.) is manually changed from a standard value to a desired value after automatic adjustment, an automatic adjustment method for matching the tone between cameras has not been established.

(Ll-like) In order to eliminate these drawbacks, this invention uses the green video signal value of the reference camera as the reference value.

We provide a device that automatically adjusts the tone of each camera to match the color reproducibility of the controlled camera with that of the reference camera by inputting the input to other (controlled) cameras in advance and imaging the same chard with each camera. It is something to do.

(Example) An example of the present invention will be described below. FIG. 4 is a system block diagram. Year-round control Hei 1 has n cameras (
In this figure, camera control unit 2. ~2n and camera head part 3.
The explanation is given by taking as an example a 2-beam camera consisting of 31].

41, 42.4n from the centralized control Oki 1 to each camera control unit 2. This is the control signal that is output to ~2n.

Each of the camera control units 2, to 2n is connected to each of the camera heads 3I to 3n by a camera double.Now, the first camera is connected to the reference camera.

Taking as an example the case where the tone of this camera is automatically adjusted to another camera, the camera control unit 2. green image (i output (
Gch output) is output from terminal 5.

This Gch output is inputted to the reference signal input terminal 7 of another camera via the signal line 6. Each camera is white.

A special chart h8 containing gray and black components (standard gray scale may be used) is imaged under the same conditions.

FIG. 2 shows an example of the special chart 8 of FIG. 4.

9 is a dot portion, 10 is an intermediate color (gray) portion, and 11 is a white portion.

Next, an example of an actual automatic tone adjustment procedure will be shown with reference to the flowchart of FIG. The steps in this flowchart are blank (BLACK), gain (GA, IN)
, GAMMA , FLARE
However, the control order may be changed depending on the characteristics of the controlled circuit of the camera, or a specific item may be controlled multiple times.

FIG. 1 is a block diagram of a camera control section of a controlled camera showing the principle of tone matching control of the present invention. This control method is common to all control items. iiR, 11
G and 1.1B are the Rch of the controlled camera, respectively.
This is a Gch and Bch video signal processing circuit. These video signal outputs 1.2R, 12G, 12B and the (jch output (input from terminal 7) 13 of the reference camera are input to a multiplexer 14. The multiplexer 14 is controlled by a microprocessor (input from terminal 18).

A specific part of this signal (the part corresponding to white, intermediate color, or black of Chari) is sampled by the sampling switch 19, and after being held in the bold capacitor 20,
7. Connect the A/D converter 21 to Beniyama. microprocessor 15
Enter. In accordance with the procedure shown in FIG. 3, the microprocessor 15 calculates a control amount for each term 1] that makes the difference signal between the signals to be compared zero, and calculates this control amount 23R, 2
3G, 2:3. , through the D/A converter 22, and the video signal processing circuit 11. , , 11o, i, and IB for respective control. , Knead') are feedback-controlled until the difference signal read by the microprocessor 15 becomes zero.

(Effects) The present invention enables automatic adjustment of the 1-tone alignment of each camera. Further, by manually adjusting the reference camera to a desired value and then performing the automatic adjustment according to the present invention, other cameras can also obtain the same tone (color reproducibility) as the reference camera.

[Brief explanation of drawings]

FIG. 4 is a system block diagram of the present invention, FIG. 2 is an example of a chart, and FIG. 3 is a control flow chart of the present invention.
The figure is a block diagram showing the principle of control of the present invention. 11□, 11G, 11B: Video signal processing circuit, 13: Green video signal of the reference camera, 14: Multiplexer. 15: Microprocessor, 16: Differential amplifier, 19:
Zample Suinochi, 20: Hold capacitor.

Claims (1)

[Claims] In tone matching (color reproducibility) of multiple color television cameras, a chart containing white, intermediate color (gray), and black is imaged by each camera, and the green video signal output of the camera is used as a reference at this time. means for comparing the green video signal output of the reference camera with its own green video signal in each controlled camera; and means for comparing the green video signal of the reference camera with its own green video signal; means for comparing the blue video signal; and a means for comparing the blue video signal;
a means for extracting a signal of intermediate color or black), and a means for extracting a signal of
After /D conversion, the control amount for each factor is calculated to make this video difference signal zero, and after D/A conversion, this control amount is output as feedback to the corresponding video signal processing circuit of each controlled camera. During these automatic adjustments, the necessary camera on/off control (ND filter close, etc.) for each control factor can be performed on all cameras, including the reference camera, from the central control console that centrally controls the multiple cameras mentioned above. 1. A color television camera device comprising: means for issuing a command to the camera; and means for automatically controlling each factor in each camera according to a certain sequence in conjunction with the command.