JP2008199207A - Control display method of television camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control display method which facilitates manual adjustment or remote adjustment of white balance during photographing without using measuring instruments only for video images. <P>SOLUTION: A color imaging apparatus includes: a means for manual adjustment or remote adjustment of white balance; a means for calculating a subject color temperature or controlled variables like color gains necessary for white balance adjustment of a subject from peaks obtained by removing excessive signals of image signals of respective colors; and a means for displaying the subject color temperature or the controlled variables on a view finder or a picture monitor, wherein a set color temperature of the imaging apparatus and the color temperature of the subject are displayed in parallel on the view finder or the picture monitor or color controlled variables necessary for white balance adjustment of the subject are displayed there. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an improvement of a television camera.

Conventionally, in a color television camera, a so-called white balance adjustment of a video signal is performed to correct a difference in wavelength distribution of light emitted from a light source to a subject. The white balance adjustment described above includes one-time correction in which white balance adjustment is performed only once at an arbitrary time point and real-time correction in which white balance adjustment is always performed. In the one-time correction, information on the adjustment result and the color temperature of the subject is displayed at the end of the white balance adjustment. (See Patent Document 1)
In addition, the image taken with manual white balance and the color temperature set for the camera at that time are displayed on the upper left of the screen, and the temperature information of the subject at the time of shooting calculated with auto white balance and the color temperature are set on the upper right of the screen. There has been proposed a technique of an electronic camera that displays a simulation image when the image is taken. (See Patent Document 2)
Furthermore, there has been proposed a television camera technique that removes an excessive signal of video signals of each color such as specular reflection of illumination light during white balance adjustment. 4 is realized by a gate circuit 9, an excessive signal removal unit 10, a peak detection unit 11, and a control unit (CPU) 12 in the block diagram showing the configuration of the conventional television camera of FIG. 4. Details will be described in the best mode for carrying out the invention. (See Patent Document 3)
In general, home television cameras perform real-time correction to continue white balance adjustment, whereas broadcast television cameras generally have white balance manually or remotely adjusted by a cameraman, a video engineer, or the like. The white balance can be adjusted by adjusting the sensitivity of the red and blue image sensors, adjusting the red and blue gain, adjusting the color difference gain, and adjusting the color temperature. There is.
JP-A-8-322061 JP 2001-251635 A JP 2004-289701 A

  Broadcast television cameras generally adjust the white balance manually or remotely. However, if you do not use a video monitor called a waveform monitor or vector scope, you can manually adjust the white balance during shooting. Or remote adjustment was difficult.

  An object of the present invention is to provide a control display method that solves these problems and facilitates manual adjustment or remote adjustment of white balance without using a dedicated measuring instrument.

  In order to solve the above problems, the present invention provides a color imaging apparatus having means for adjusting white balance, displaying the set color temperature of the imaging apparatus and the color temperature of the subject in parallel, or adjusting the white balance of the subject. At least one of the control amounts necessary for the display is displayed.

  Specifically, in the imaging apparatus, at least one of means for manually adjusting white balance or means for remotely adjusting, an imaging unit, a gate unit for extracting a video signal in a predetermined range from each color video signal, and a video signal An excessive signal removing unit that removes an excessive signal, a peak detecting unit that detects a white level of a video signal, a control unit that calculates control information from the output of the peak detecting unit and controls color sensitivity or color gain of the imaging unit; A character output unit for displaying the control information on a viewfinder or a screen monitor, and the set color temperature of the imaging device as a change in the number or color of pseudo-bar graphs by character information or characters on the viewfinder or screen monitor. Display the color temperature of the subject in parallel, or display the control amount required to adjust the white balance on the subject.

  According to the present invention, the set color temperature of the television camera and the color temperature of the subject are provided in real time to the cameraman or video engineer as character information on the viewfinder or screen monitor even when the white balance is not automatically adjusted. To do. Alternatively, control information necessary for white balance adjustment, such as red and blue image sensor sensitivity or red and blue gain or color difference gain or color temperature, can be displayed on the viewfinder or screen monitor using text information or bar graphs or characters. By displaying it as a change in the number of bar graphs or as a color change in a pseudo bar graph due to characters, it is provided to photographers and video engineers.

  As a result, the white balance can be easily adjusted manually or remotely even during shooting without a dedicated image measuring device.

  FIG. 1 is a diagram showing a display screen of a color control amount necessary for a subject in one embodiment of the present invention in FIG. 1 and a setting of a television camera in another embodiment of the present invention in FIG. This will be described with reference to a diagram showing a display screen of color temperature and subject color temperature and a block diagram showing the configuration of the television camera of the present invention in FIG.

  FIG. 3 which is a block diagram showing the configuration of the television camera of the present invention is different from FIG. 4 which is a block diagram showing the configuration of a conventional television camera in the character output unit 13. In FIG. 3, 1 is a lens, 2 is a color television camera, 3 is a viewfinder, and 4 is an image monitor. Reference numeral 5 denotes a color separation optical system (generally a prism). 6, 7, and 8 are image pickup units, which generally convert to a CCD image pickup device, CDS (Correlated Double Sampling) for removing noise, dark current correction, variable gain amplification circuit (hereinafter referred to as automatic gain control, AGC), and digital video signal Vi It consists of a front end processor (FEP) incorporating an ADC (Analog Digital Converter) and a CCD drive circuit. 6, 7, and 8 may be a CMOS image sensor integrated with the above functions, or an ultra-sensitive image pickup tube and a peripheral circuit. 9 is a gate circuit, 10 is an excessive signal removing unit, 11 is a peak detecting unit, 12 is a control unit (CPU), and 13 is a character signal output unit.

In FIG. 3, the white balance adjustment is performed by adjusting the gain of each color video signal or adjusting the sensitivity of the image sensor so that each of the red Ro, green Go, and blue Bo video signals is 1: 1: 1 when imaging a white subject. It is made to adjust. Conventionally, the white balance correction circuit shown in FIG. 3 has been used, and the peak value of each of the red Ro, green Go, and blue Bo video signals is detected by the level detector so that the peak values of the respective video signals are equal. A method of adjusting the gain of red and blue signals is used. Based on the gain control values of the red and blue signals obtained by adjusting the white balance, the color temperature of the subject is calculated by the following approximate expression.
Sixth order approximation formula:
^{Y = (0.0000005 * X 6 -} 0.000002 * X 5 - 0.00006 * X 4 + 0.0006 * X 3
^{+ 0.0096 * X 2 - 0.1445 *} X + 3.1848) * 1000
X: Red and blue gain difference = (Rg-Bg) dB
Based on the control amount or color temperature information Ch1 or Ch2 sent from the control unit 12, the character signal output unit 13 superimposes the character information on the video. As a result, the obtained color temperature is displayed as character information on the viewfinder or the screen monitor.
The color temperature of the subject is calculated in real time by the following method.

Without white balance adjustment, the current gain control values Rg, Bg of the red and blue signals and the peak values (Rp, Gp, Bp) of the red Ro, green Go, and blue Bo video signals detected in real time. ), The addition gain control values ΔRg and ΔBg of the red and blue signals necessary for the red Ro, green Go, and blue Bo video signals to be 1: 1: 1 are obtained, and the gain of Rg + ΔRg, Bg + ΔBg is obtained. The difference is calculated as X from the above approximate expression. Peak value detection and color temperature calculation at this time are performed for each field.
ΔRg = 20 * log (Gp / Rp), ΔBg = 20 * log (Gp / Bp)
Based on the control amount or color temperature information Ch1 and Ch2 sent from the control unit 12, the character signal output unit 13 superimposes the character information on the video. As a result, the color temperature obtained as described above is set as a television camera in real time as the subject color temperature, as shown in the figure showing the display screen of the set color temperature and the subject color temperature in another embodiment of the present invention in FIG. It is displayed as character information on the viewfinder or screen monitor together with the color temperature.

  Further, as shown in FIG. 1A showing a display screen of the color control amount necessary for the subject of the embodiment of the present invention in FIG. 1, the difference between the set color temperature and the subject color temperature is displayed on the viewfinder or the screen monitor. Display as information. Alternatively, when the above addition gain control values ΔRg and ΔBg are displayed on the viewfinder or the screen monitor, the character information as shown in (b) of FIG. 1 is used as the pseudo information by the character as shown in (c) of FIG. The change in the number of bar graphs may be displayed as the color change of the pseudo bar graph by the character as shown in FIG.

  The added color control value displayed on the viewfinder or the screen monitor may be not only the above-described red and blue gains but also a color difference gain. Further, when a variable sensitivity image sensor such as an electron multiplying image sensor is used, the sensitivity of the image sensor may be controlled.

The display of the real-time color temperature and the necessary control amount can be set to display / not display (ON / OFF) according to user settings.

The figure which shows the display screen of the color control amount required for the to-be-photographed object of one Example of this invention The figure which shows the display screen of the setting color temperature and subject color temperature of the television camera of other one Example of this invention. 1 is a block diagram showing a configuration of a television camera of the present invention. Block diagram showing the configuration of a conventional television camera

Explanation of symbols

1: lens, 2: color television camera, 3: viewfinder,
4: Image monitor, 5: Color separation optical system, 6, 7, 8: Imaging unit,
9: Gate section, 10: Over-signal removal section, 11: Peak detection section,
12: Control unit (CPU), 13: Character output unit
Bo: Blue video signal, Go: Green video signal, Ro: Red video signal,
B1, G1, R1: Video signals of each color gated
B2, G2, R2: Video signals of each color that have undergone over-signal removal processing,
B3, G3, R3: Peak detection value of video signal of each color,
Gr: Red gain control voltage, Gb: Blue gain control voltage
Ch1, Ch2: Control amount or color temperature information

Claims (1)

In a color imaging apparatus having means for adjusting white balance, the set color temperature of the imaging apparatus and the color temperature of the subject are displayed in parallel, or the control amount necessary for adjusting the white balance of the subject is displayed. A control display method for an imaging apparatus, characterized in that at least one of the above is implemented.

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