JPS63208387A - Color camera equipment - Google Patents

Abstract

PURPOSE:To attain color pickup with excellent picture quality by forming a white balance gate signal so as to detect the deviation of white balance from the signal level ratio of three primary color signals gated by the white balance gate signal thereby applying alarm display. CONSTITUTION:Each color data representing the signal level of the three primary color signal of a white level of an object image picked up by an image pickup section is written sequentially in a memory 18 to calculate mean value data (Ar, Ag, Ab) for several number of times. At the alarm display mode, the Ar/Ag, Ah/Ag are calculated from the mean value data and compared with a criterion (Kr, Kb) being the deviation of white balance so as to discriminate whether or not the value is within the reference range of 1/Kr<Ar/Ag<Kr 1/Kb<Ab/Ag<Kb. When the value is at the outside of the criterion, the display output such as (COLOR TEMP.HIGH) and (COLOR TEMP. LOW) is outputted from the character generator 19 to apply alarm display.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a color camera device that forms and outputs a color video signal from three primary color signals obtained by photographing a subject image with a color imaging section.

[Summary of the invention]

The present invention provides a color camera device that forms and outputs a color video signal from three primary color signals obtained by photographing a subject image in a color imaging section, in which a deviation in white balance of the three primary color signals obtained in the color imaging section is corrected. A warning is displayed when the amount increases beyond a predetermined value.

[Conventional technology]

-i, in a color camera device, the imaging light from the subject is separated into the three primary color light components R, G, and B using a color separation system, and color imaging is performed using an image pickup tube or solid-state image sensor, and color images are obtained from the imaging output. If the color temperature changes due to lighting conditions during imaging, the white balance will be disrupted and color reproducibility will be impaired, so in order to obtain a color video signal with good color reproducibility, , it is necessary to accurately adjust the white balance according to the color temperature during shooting.

White balance adjustment is performed by photographing a white subject and adjusting the ratio of the signal level Er of the red component, the signal level Eg of the green component, and the signal level Eb of the blue component of the image pickup output to Er.
This is done by setting the level adjustment circuit provided for each color signal line so that :Eg:Eb=1:1:1. Conventionally, the Japanese Patent Publication No. 53-2 gated the imaging output of the white part of the subject image, detected the white balance error, and performed automatic white balance adjustment.
A liquid color balance device as disclosed in Japanese Patent Publication No. 290, a television camera as disclosed in Japanese Patent Publication No. 56-24884, etc. have been provided.

[Problem that the invention seeks to solve]

By the way, in general, color camera devices monitor the image of the subject being photographed using a black and white viewfinder and take color photographs from the camera, so even if the white balance collapses during photographing, it is difficult to notice.

Traditionally, color camera devices have been able to adjust the white balance automatically or manually depending on the lighting conditions during shooting. Even if a color camera device is equipped with an automatic white balance adjustment function, white objects are not constantly photographed, so the white balance may be significantly disrupted.

In view of the above-mentioned problems, the present invention provides a warning display to alert the photographer when the white balance is disrupted by more than a predetermined level during color photography, thereby reducing the deterioration of color reproducibility due to white balance errors. An object of the present invention is to provide a color camera device with a novel configuration that can prevent such problems from occurring.

Means for Solving Problems c] In order to solve the above-mentioned problems, the present invention provides a color video signal that forms and outputs a color video signal from three primary color signals obtained by photographing a subject image with a color imaging section. In the camera device, gate signal forming means forms a white balance gate signal from a signal obtained by combining three primary color signals output from the color imaging section, gate means gates each of the three primary color signals using the gate signal, and the gate means Compare the signal levels of each color signal averaged over a predetermined period for the three primary color signals gated at , find the signal level ratio of other color signals to a specific color signal, and compare it with a preset signal level ratio. and warning display signal forming means for detecting that the white balance deviation has increased beyond a predetermined value and forming a warning display signal, the white balance deviation of the three primary color signals obtained by the color imaging section has increased beyond the predetermined value. The feature is that a warning is displayed when this occurs.

[Effect]

In the color camera device according to the present invention, a white balance gate signal is formed from a signal obtained by combining the three primary color signals output from the color imaging section, and the white balance gate signal is determined from the signal level ratio of the three primary color signals gated by the gate signal. A warning display is performed by detecting a deviation in the white balance of the three primary color signals obtained by the color imaging section.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a color camera device according to the present invention will be described in detail below with reference to the drawings.

The embodiment shown in FIGS. 1 to 3 has three CCDs (
The present invention is applied to a so-called three-chip color video camera in which a color imaging section 1 is composed of image sensors IR, IG, and IB (Charge Coupled Device).

In this embodiment, the three primary color signals (Er, Eg, Eb) obtained by capturing a subject image with each CCD image sensor IR, IG, and IB of the color imaging unit 1 are as shown in FIG. Preamplifier 2R, 2G respectively
, 2B to the white balance adjustment circuit 3, the white balance adjustment circuit 3 performs white balance adjustment, and then the process processing circuit 4R.
, 4G, and 4B to an encoder 5 and a white balance processing circuit 6.

The encoder 5 includes each of the process processing circuits 4R, 4.
Three primary color signals (Er, Eg) that have undergone processing such as gamma correction in G and 4B, respectively.

For example, a color video signal (Sout) compatible with the NTSC system is formed from Eb) and outputted from the first signal output terminal 7. Furthermore, the encoder 5 sends a video signal (S
eb) is converted into the three primary color signals (Er, Eg
, Eb) and is supplied to the signal synthesizer 8.

The signal synthesizer 8 synthesizes the display output signal (A) supplied from the white balance processing circuit 6 described below with the video signal (S eb) and outputs the signal from a second signal output terminal 9 to an electronic viewfinder (not shown). is supplied to.

The white balance processing circuit 6 also includes three primary color signals (Er
, Eg, Eb) are supplied to the signal adder/synthesizer 11, and are also supplied via the multiplexer 12 to the sampling gate circuit I3.

The signal addition/synthesizer 11 processes the three primary color signals (Er, E
g, Eb) to form a composite signal (S) with a signal level indicating the brightness level of the subject image being photographed by the imaging unit 1, and this composite signal (S) is subjected to peak detection. It is supplied to the circuit 14. The peak detection circuit 14 detects the peak level portion of the composite signal (S), that is, the white portion of the subject image, and supplies the detection output to the sampling gate circuit 13 as a white balance gate signal.

Further, the multiplexer 12 sends the three primary color signals (Er, Eg
, Eb) are controlled by the microcomputer 16 to sequentially select them.

Further, the sampling gate circuit 13 receives the three primary color signals (Er, Eg) which are sequentially supplied via the multiplexer 12 every frame period.

Eb) is sampled using a white balance gate signal supplied from the peak detection circuit 14 and supplied to an analog-to-digital (A/D) conversion circuit 15. Above A
/D conversion circuit 15 is the sampling gate circuit 13
The three primary color signals (Er, Eg) of the white part of the subject image sampled at

Eb) is digitally read, and the color data (
Dr, Dg, Db) are supplied to the microcomputer 16.

In this embodiment, the microcomputer 16 controls the three primary color signals (Er, Eg, Eb) obtained by the imaging section 1 by photographing a reference white subject using the color temperature of the imaging light source. Based on each color data (Dr, Dg, Db) indicating each signal level, green signal (
The ratio of each signal level of other color signals (Er, Eb) to Eg) is calculated, and the above three primary color signals (Er, Eg, Eb) are calculated.
Red level control signal (Δr) to match the signal level of
The blue signal (Δb) is sent from the Voight Harance control circuit 17 to the gain control circuit 3R of the red signal (Er) that constitutes the white balance adjustment circuit 3 and the blue signal (
Control data to be supplied to the gain control circuit 3B of Eb) to ensure white balance is stored in advance in the memory 18, and a white balance adjustment operation is performed using the control data during actual photographing operation.

Further, the microcomputer 16 performs a white balance adjustment operation using the control data during actual photographing operation, and also performs a white balance adjustment operation using the control data, and also performs each color data (Dr, Dg, etc.) supplied from the A/D converter 15.

Db) is used to perform display control operations as shown in the flowchart of FIG.

That is, the warning display operation by the microcomputer 16 begins with the three primary color signals (Er.

The A/D converter 15 indicates the signal level of Eg, Eb).
Each color data (Dr, Dg.

Db) are sequentially written into the data memory 17. and,
For each color data (Dr, Dg, Db), average value data (Ar) of several values.

A g, A b) are calculated. Next, the display mode is determined, and in the warning display mode, the above average value data is displayed.
Ar/Ag, Ab/Ag are calculated from (Ar, Ag, Ab), and the reference value for white balance deviation (Kr, K
b), 1/K r < A r / A g < K r
l / K b < A b / A g < K b
It is determined whether or not it is within the reference range, and if it is outside the reference range (COLORTEMP, HIGH).

(COLORTEMP, LOW) or the like is output from the character generator 19 to display a warning;
If it is within the standard range, the display is turned off. In addition, when the result of the display mode determination is the color temperature display mode, the amount of deviation from the white balance state indicated by the value of Ar/Ab obtained from the average value data (Ar, Ag, Ab) and the imaging The actual color temperature value is calculated from the type of filter arranged in the optical system and the gain control amount of each gain control circuit 3R, 3B of the white balance adjustment circuit 3, and the display output of this value is sent to the character generator 19. output from to display color temperature.

〔Effect of the invention〕

As is clear from the description of the embodiments described above, in the color camera device according to the present invention, a white balance gate signal is formed from a signal obtained by combining three primary color signals output from a color imaging section, and a gate signal is formed using the gate signal. The system detects a deviation in the white balance of the three primary color signals obtained by the color imaging section from the signal level ratio of the three primary color signals obtained by the color imaging section and displays a warning. The above-mentioned warning display alerts the photographer, making it possible to prevent deterioration of color reproducibility due to white balance errors, and to perform color photography with good image quality.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a color camera device according to the present invention, FIG. 2 is a block diagram showing a specific configuration of a white balance processing circuit in the above embodiment, and FIG. 3 is a flowchart for explaining a warning display control operation by a microcomputer provided in the white balance processing circuit. ■...Imaging section IR, IC, IB...COD image sensor 3...
White balance adjustment circuits 3R, 3B... Gain control circuit 5... Encoder 6... White balance processing circuit 8... Signal synthesizer 11... Signal addition synthesizer 12... Multiplexer 13... Sampling gate circuit 14...Peak detection circuit 15...A/D converter

Claims (1)

[Claims] In a color camera device that forms and outputs a color video signal from three primary color signals obtained by photographing a subject image with a color imaging section, a signal obtained by combining the three primary color signals output from the color imaging section. a gate signal forming means for forming a white balance gate signal; a gate means for gating each of the three primary color signals using the gate signal; and regarding the three primary color signals gated by the gate means,
By comparing each color signal level averaged over a predetermined period to find the signal level ratio of other color signals to a specific color signal and comparing it with a preset signal level ratio, the white balance deviation is determined to be more than a predetermined value. and a warning display signal forming means for detecting an increase in the white balance of the three primary color signals obtained by the color imaging section and generating a warning display signal when the white balance deviation of the three primary color signals obtained by the color imaging section increases beyond a predetermined value. A color camera device characterized by: