JPS60248092A - Special effect generator - Google Patents

Abstract

PURPOSE:To obtain an excellent picture image inserting effect while the effect of color blurring of a background color is avoided effectively by obtaining a chromachy pulse based on a color signal after color blurring of the background color is corrected. CONSTITUTION:A key side video signal KYV is inserted to a circuit system giving a chromachy pulse CON to a mixing circuit 35. A color difference signal CRD is compared with a reference voltage VR3 at a comparator 38 and the voltage VR3 is set to a signal corresponding to the colored black ground color. Thus, a pulse CON with a pulse width corresponding to a part other than subject to background color from the circuit 38 is detected and it is given to the circuit 35. The circuit 35 uses the signal KYV from an insert side video signal INV so as to attain keying when the pulse CON rises and outputs a chromachy signal CVO where a picture corresponding to the signal KYV is inserted in the timing when the pulse CON rises to the picture formed by the signal INV.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a special effect generating device, and more particularly to an improvement in a chromakey device.

[Background technology and its problems]

As shown in Figure 2, the chromakey device used when producing television programs places a subject 2 having a color different from the background color in front of a background 1 colored chromakey blue as the background color. to obtain a television video signal corresponding to chromakey image 3,
The insert image 4 is obtained by obtaining a chroma key pulse that is generated at the same timing as when the color portion other than the background color of this television video signal is punched out, and keying the video signal of the insert image 4 with the chroma key pulse.
It is configured to synthesize a chromakey composite image 5 in which the subject 2 is embedded.

However, when the background 1 and the subject 2 are actually imaged with a television camera, the background 1 is not imaged as a uniform background color due to uneven lighting, etc., and this color unevenness cannot be completely keyed. There is.

Particularly, this color unevenness occurs at the periphery of the background l.

In order to solve this problem, conventionally, a mask 6 is applied to the chromakey image 3 using a wipe key pulse, etc., as shown by the broken line, and a chromakey pulse is used only for the chromakey side video signal corresponding to the part inside the mask 6. While keying to extract subject 2,
A method is adopted in which the outer portion of the mask 6 is removed from the screen without using a chromakey pulse.

However, if you use this method to easily mask the subject 2 by providing one mask 6, if there is an image part 7 that you want to leave together with the subject 2 at a location away from the subject 2, Since this is outside the mask 6, it has the disadvantage that it is removed during keying. As a countermeasure, it would be possible to provide a plurality of masks 6, but in practice, it would be necessary to generate wipe key pulses, etc., which are quite complicated, and in the end, there remains the problem that keying cannot be performed simply. Become.

[Purpose of the invention]

The present invention has been made in consideration of the above points, and attempts to correct color unevenness in the background color using a method different from conventional mask processing methods, thereby making it possible to obtain a good ROMA key composite image. It is something.

[Summary of the invention]

A color unevenness correction circuit is provided that corrects the color signal included in the chroma key side video signal in accordance with a predetermined correction waveform for each period of the synchronization signal, and the color signal is corrected based on the key side corrected video signal obtained from the color unevenness correction circuit. to obtain a chromakey pulse.

〔Example〕

An embodiment of the present invention will be described in detail below with reference to the drawings.

In the present invention, a color unevenness correction circuit 11 shown in FIG.
Correction is performed using the color unevenness correction signal CC8 obtained in .

The color unevenness correction circuit 11 uses a reference horizontal synchronization signal HD (see Fig. 3).
A)) The sawtooth wave generation circuit 12 generates a sawtooth wave signal SL (third
(B)), and in the comparison circuit 13, a reference voltage V is applied from a horizontal position adjuster 14 made of, for example, a variable resistor.
Compare with RI. When the sawtooth signal Sl exceeds the reference voltage VRI, a trigger signal S2 (FIG. 3(C)) is applied to the mono multivibrator 15, thereby sending the reference horizontal synchronizing signal H to the output end of the mono multivibrator 15.
Horizontal synchronizing pulse S3 that rises at a time point corresponding to the adjustment position of the horizontal position adjuster 14 in section IH of one cycle of D
(Figure 3(D)) is obtained. This horizontal synchronizing pulse S3 is given to the correction waveform generation circuit 16 as a drive signal.

The correction waveform generation circuit 16 generates a horizontal correction signal S4 that changes along a predetermined correction waveform, for example, a parabolic waveform, in synchronization with the horizontal synchronization pulse S3.
As shown in FIG. 3(E), the sawtooth signal S5 is formed by integrating once with the horizontal synchronizing pulse S3, and then this sawtooth signal S5 is integrated twice to form the sawtooth signal S5 as shown in FIG.
A horizontal correction signal S4 having an almost parabolic waveform as shown in F) is generated.

Also, for the reference vertical synchronization signal VD, in the same manner as for the reference horizontal synchronization signal HD, the sawtooth wave signal S11 generated in the sawtooth wave generation circuit 22 is output to the comparison circuit 23 at the vertical level Wil! The trigger signal S12 is compared with the output voltage VR2 of the commutator 24 and is set as the mono-multi-by-break 25.
A vertical synchronizing pulse 313 having the same period as the reference vertical synchronizing signal VD is generated at its output terminal, and by performing an integral operation twice based on this vertical synchronizing pulse S13, a vertical correction signal S14 having an approximately parabolic waveform is generated. Send out.

The thus obtained horizontal correction signal S4 and vertical correction signal 3
14 are combined with each other through combining resistors 31 and 32, and the combined signal S15 is provided to the gain control amplifier circuit 27.

The gain control amplifier circuit 27 is configured to be able to control the gain in both positive and negative directions from a gain state of 0 by adjusting the gain adjuster 28. Thus, when the gain is positive polarity, the fourth
As shown in Figure (A), the horizontal correction signal S repeats a parabolic waveform that rises in the positive direction every horizontal synchronization period IH.
A color unevenness correction signal CC8 is provided to the modulation circuit 29, which is a signal similar to that in which the signal level of the signal component No. 4 is varied by a vertical correction signal 314 that repeats a parabolic waveform at a period of 1v in one vertical section. On the other hand, when the gain set by the gain adjuster 28 is negative, as shown in FIG. 5(A), the color b? , a color unevenness correction signal C obtained by reversing the way the signal components of the horizontal correction signal S4 and the signal components of the vertical correction signal S14 of the correction signal CCS change.
C3 will be sent to the modulation circuit 29.

The modulation circuit 29 receives the key side video signal KYV (Fig. 4(B)
The amplitudes of FIG. 4(C) and FIG. 5(C) are controlled by the color unevenness correction signal CC8.
As shown in , a color difference signal CRM is obtained by changing the color signal component included in the key side video signal KYV into a parabolic waveform in accordance with changes in the color unevenness correction signal CC8 for each horizontal interval IH and each vertical interval IV. (Key side correction video signal MKV including FIG. 4(C) and FIG. 5(C))
Send out.

As shown in FIG. 6, the color unevenness correction circuit 11 having such a configuration mixes the insert side video signal INV with the key side video signal KYV in the mixing circuit 35 to obtain the chroma key output signal CVO. It is inserted in a circuit system that provides a chromakey pulse CON to the mixing circuit 35.

That is, the key side video signal KYV is converted into the key side corrected video signal MKV in the color unevenness correction circuit 11 (FIG. 1).
, this key-side corrected video signal MKV is given to a luminance signal/chrominance signal separation circuit 36.

This separation circuit 36 separates the color signal CRM from the key side corrected video signal MKV, and converts it into a color difference signal CHD having a signal level corresponding to each color of the video signal in a detection circuit 37. This color difference signal CHD is compared with a reference voltage VR3 of a reference voltage source 39 in a comparison circuit 38. The reference voltage VR3 is set to a signal level corresponding to the background color colored in the background 1, and the comparison circuit 38 sends out a chromakey pulse CON having a pulse width corresponding to the portion other than the portion where the background color is intensified. , which is applied to the mixing circuit 35.

Mixed episode Il! 35 keys the key side video signal KYV from the insert side video signal INV when this chromakey pulse CON rises, and thus adds the chromakey signal C to the image formed by the insert side video signal INV.
At the timing when ON' rises, the key side video signal KY
The mixing circuit 35 outputs a chromakey output signal C■0 in which the image corresponding to V is inserted.

With the above configuration, the color unevenness correction circuit 11
(Figure 2), when there is color unevenness at the periphery of the key-side video signal KYV (Figure 6), the hue at both ends of the key side video signal KYV (Figure 6) differs from the hue at the center for each horizontal synchronization period and vertical synchronization period. When a phenomenon in which the hue changes occurs, a horizontal correction signal S4 and a vertical correction signal S14 having characteristics to correct such a change in hue are generated (Fig. 1), thus changing the key side video signal KYV. It is possible to obtain a key-side corrected video signal MKV in which the included color unevenness is corrected.

Therefore, in the mixing circuit 35 (FIG. 6), the chromakey pulse CON corresponds accurately to the image part that is desired to be preserved when there is no color unevenness in the background color, and therefore the key side video signal KYV in the chromakey output signal C The inset of the image based on is practically unaffected by the red unevenness of the background 1.

According to the above configuration, the part of the image that you want to keep is background 1.
Even if there are multiple spots scattered within the unevenly colored part,
It is possible to obtain chromakey pulses that accurately correspond to the plurality of image portions to be preserved without being affected by this color unevenness. In this way, there is no need to use a complicated configuration such as creating a separate wipe key pulse or the like in a complicated manner as in the case of the conventional mask method.

In the above, a case has been described in which a parabolic waveform is used as the waveform of the correction waveform generation circuits 16 and 26, but the point is that this is not limited to this. A waveform that can be corrected may be used.

Furthermore, in the above description, as shown in FIG. 6, a case has been described in which the color unevenness correction circuit 11 is provided at the front stage of the luminance signal/chrominance signal separation circuit 36 to directly correct the key side video signal KYV. Instead, it may be provided, for example, after the detection circuit 37 to correct color unevenness in the detection output CHD.

〔Effect of the invention〕

As described above, according to the present invention, a chromakey pulse is obtained based on a color signal after correcting the unevenness of the background color, thereby producing a good image that effectively avoids the influence of the unevenness of the background color. You can get the inset effect.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of a color unevenness correction circuit applied to a special effect generating device according to the present invention, FIG. 2 is a route diagram for explaining problems when obtaining a chromakey composite image, and FIG. 3 5 is a signal waveform diagram showing the signals of each part in FIG. 1, and FIG. 6 is a block diagram showing a special effect ordering circuit using the color unevenness correction circuit of FIG. 1. l... Background, 2... Subject, 3. Old.
・Chromakey image, 4...Insert image, 5
...Chromakey composite image, 6...Mask, 7...Image part to be left, 11...
・Color unevenness correction circuit, 12.22... Sawtooth wave generation circuit, 13.23... Comparison circuit, 15.2
5...Mono multi-by break, 16.26.
... Correction waveform generation circuit, 27 ... Gain control amplifier circuit, 29 ... Modulation circuit. Agent Keiki Tanabe

Claims (1)

[Claims] In a special effect generating device that forms a chromakey pulse corresponding to an image to be fitted to an insert side video signal based on a chromakey side video signal, and keys the chromakey side video signal with respect to the insert side video signal using the chromakey pulse. , has a color unevenness correction circuit that corrects the color signal included in the chromakey side video signal in accordance with a predetermined correction waveform for each period of the synchronization signal, and the key side correction obtained from the color unevenness correction circuit. A special effect generating device characterized in that the chroma key pulse is obtained based on a video signal.