JPS6113888A - Real time flare adjustment method in television camera device - Google Patents

Abstract

PURPOSE:To obtain optimum flare tracking in real time by photographing an ordinary subject, changing a video signal input at every step up to 0-100%, adjusting automatically flare amounts of red, green and blue colors, and storing them. CONSTITUTION:According to a sequence of software built-in a processing circuit 13, first, it controls an iris value control signal 17 to a lens 1 at every certain step, monitoring an average video level, secondary controls control signals 14, 15 and 16 of flare amounts of red, green and blue colors so that a black level of each channel detected in a detection circuit 12 can be constant, and inputs and stores the flare control amount corresponding to each video average level. The flare control amount corresponding to the detected average video signal level is detected from a memory circuit 18 in the real time by software processing, and given to respective flare correction circuit 9, 10 and 11, thereby executing the optimum flare correction in the real time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a method for automatically adjusting flare in a television camera having an automatic adjustment function.

(Prior art and its problems) The conventional automatic flare adjustment method involves taking an image of a special chart built into the lens or a similar special chart for outside photography, and detecting the white level included in the chart.

After adjusting this to a video signal level that is not specified as 100%, the non-reflection black level is detected, and flare is automatically adjusted so that this black level is the same as the black level when no signal is input. Ask questions listed in item 1.

(1) When performing automatic adjustment using the lens built-in chart.

Flare that occurs in the lens system cannot be corrected.

(2) Approximately 100 for both the built-in chart and the external chart
At the video signal level, black areas are detected and flare is corrected, but the iris value is fixed and depends on the correction curve of the flare correction circuit and the amount of flare that occurs in the actual lens and color separation optical system. However, since it may differ depending on the video signal input, approximately 60
% indicates when any video signal level is input, and even with this automatic flare adjustment diameter, the flare may not be corrected or may be overcorrected in the red, green, and blue signal outputs, and the video signal level is changed.

Flare tracking between each channel is excellent.

(Objective) In order to solve these drawbacks, the present invention images a general subject containing a non-reflective black component and a white component.

The video signal input is varied in advance from 0 to 100% in fixed steps using a lens iris, etc., and the amount of red, green, and blue flare is automatically adjusted and memorized at each step to minimize the amount of flare. put. The flare automatic adjustment feature is characterized in that it then detects the input video average level in real time and outputs a pre-memorized flare amount corresponding to the detected video average level to obtain the optimal flare tiger and king in real time. It's a method.

(Example) Embodiments of the present invention will be described below with reference to FIG.

An object containing a non-reflective black component and a white component passes through a lens 1 and is separated into red, green, and blue light components by a one-color separation optical system 2, and enters the corresponding image pickup device 3, 4.5. . In this incident light, the black level of the signal corresponding to the reflected color component is raised due to diffuse reflection of the light. Further, the level of this diffusely reflected light is proportional to the amount of incident light.

The signals converted into electrical signals by the image sensor 3.4.5 are amplified by red, blue, and green video signal amplifiers 6°7.8, and then sent to the flare correction circuits 9 and 10, respectively.
．． ．． 11. The respective video signals after flare correction are input to a black component and white component detection circuit 12. The detection circuit 12 detects the black component contained in the video signal, A/D converts the detected amount, and then inputs it to the processing circuit 13 centered on 0PTJ.

On the other hand, the video signal from the video signal amplifier 6.7.8 is input to the video average level detection circuit 13, which detects the average value of the video signal, converts it to VD in the detection circuit 12, and outputs it to the post-processing circuit 1.
Enter 3. The processing circuit 13 first controls the iris value control signal 17 to the lens 1 in fixed steps (iris value control) while monitoring the average image level, and then detects the iris value control signal 17 in the detection circuit 12 according to the sequence of the software incorporated therein. The control signals 14, 15 and 16 for the amount of additional color, green and blue flare are controlled so that the black level of each channel becomes constant (reference value). This operation is performed until the video signal level reaches 0% to 100% (or higher), and the flare control amount corresponding to each video average level is input and stored in the storage circuit (non-volatile memory or battery backup memory) 18. After performing the above initial settings.

In real time, the flare control amount corresponding to the detected average image signal level is stored in the memory circuit 18 through software processing.
Flare correction circuit 9, 10.1
1 to perform optimal flare correction in real time.

FIG. 2 shows the sequence of the flare amount control initial setting software. This flowchart describes one color; however, during actual control, the same operation is performed for all red, blue, and green.

First, close the iris and measure the black level when there is no signal. After that, the iris is changed by a small amount, the black level is input, and the amount of flare is controlled so that the single level becomes the same level as the black level when no signal is input. After the control, the average video level and flare control amount detected by the video average level detection circuit 19 are stored in the storage circuit 18. This operation is repeated until the white level included in the video signal reaches 100 or more.

After this initial setting, in actual operation of the force camera, the video average level is detected in real time, the flare control amount 14, 15.16 corresponding to the detected level is taken out from the memory circuit 18, and each flare processing circuit 9.10.11.By performing this operation every time the video average level changes, the amount of flare can be corrected by real-time processing. .

The following effects can be obtained.

(1) The optimal amount of flare at the average level of the valley image is determined while varying the lens iris, this value is memorized in advance, and then the memorized amount of flare corresponding to the average level of the image is output through real-time processing. You can take the flare tiger and king.

(2) Non-reflective point without using a special chart.

Just by capturing an image of a subject that includes a white component, the amount of flare can be adjusted accurately. Further, it is possible to correct flare including the lens system.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of a television camera with an automatic adjustment function including automatic flare adjustment according to the present invention, and FIG. 2 is a flow diagram of an automatic flare adjustment according to the present invention. ■=Lens, 2: Color separation optical system, 9.10.11:
Red, green, and blue flare correction circuits, respectively, 12: detection circuit, 13: processing circuit, 18: memory circuit, 19: video plane 2nd
figure

Claims (1)

[Claims] When performing automatic flare adjustment in a color television camera with an automatic adjustment function, the average level of the input video signal is changed by capturing an image of a subject that includes non-reflective black components and white components, and varying the amount of incident light in predetermined steps. let me,
The optimum flare correction amount corresponding to each level is detected and stored in advance, and the stored flare correction amount corresponding to the input video signal average level detected in real time is read out to perform automatic flare adjustment. A method for real-time flare adjustment in a television camera device.