JPH05191828A - Chromakey synthetic system - Google Patents

Abstract

(57) [Abstract] [Purpose] When multiple chromakeyers on the transmitting and receiving sides are connected by a network, the backcolor signal is not affected by the transmission characteristics of the communication system and changes in transmission characteristics. The detection operation can be automatically adjusted, and the switching operation for chroma key composition between the transmitting side and the receiving side can be made more accurate. [Structure] Detecting a predetermined back color signal, detecting whether the hue and saturation of the video signal at that time have predetermined values, and controlling the hue and saturation of the input video signal according to the error. It has a means. By incorporating such means in the transmission-side chroma keyer 100 and the reception-side chroma keyer 200, accurate chroma key combination is realized.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chroma key composition system for performing chroma key composition on a video signal transmitted via a communication line.

[0002]

2. Description of the Related Art FIG. 5A shows a conventional chroma key composition system. The subject 1 is imaged by the video camera 2 and input to the transmission side chroma keyer 3. In the transmitting chroma keyer 3, the color of the background portion of the subject 1 is replaced with the background color signal from the color generator 4. The video signal sent from the sending chroma keyer 3 is band-compressed by the codec 5 and sent to the communication line 6. On the receiving side, the video signal supplied from the communication line 6 is restored to the original band by the codec 11, and the restored video signal is supplied to the receiving chromakeyer 12. In the receiving chroma keyer 12, the background color signal area is replaced with the background video signal for composition. Thereby, on the monitor 13, an image having the background video signal synthesized on the receiving side on the background of the subject 1 can be obtained.

In the above system, when the background color signal area is specified, the transmitting side synthesizes the signal from the color generator 4 into the background color signal portion, and the receiving side detects the background color signal area and outputs the background video signal. The method of synthesizing is taken. The reason why the signal from the color generator 4 is purposefully combined with the background color signal portion in this way is that when the image of the subject 1 is picked up by the video camera 2, the hue depends on the lighting and the like.
This is because if the shift or change in saturation is emphasized and the image pickup signal is transmitted as it is, the receiving side may not be able to accurately detect the background color signal portion.

However, this system has the following unsolved problems. By the time the video signal reaches the receiving side,
That is, the encoding and decoding processes according to 1 are interposed. Then, the band compression process further enhances the hue and saturation errors. If this system is one system, it is possible to adjust the transmitting side and the receiving side in advance so that the desired background color signal detection can be obtained by the operator's adjustment. However, if a plurality of communication system paths exist. That adjustment is a problem. That is, when a large number of transmission side chromakeyers and reception side chromakeyers are connected via a network as shown in FIG. It is impossible to maintain the condition.

[0005]

As described above, in the conventional chroma key synthesizing system, when the reproduced video signal is affected by the characteristics of band compression, the correct chroma key synthesization cannot be performed on the receiving side. Need. Further, in this system, when a plurality of transmitting and receiving chromakeyers are connected by a network, it is impossible to adjust each combination.

Therefore, according to the present invention, when a plurality of chromakeyers on the transmitting side and the receiving side are connected by a network, they are not affected by the band compression characteristic of the codec and the back color signal detecting operation is performed according to the variation of the characteristic. It is an object of the present invention to provide a chroma key combination system capable of automatically adjusting the above, and making the switching operation for the chroma key combination of the transmitting side and the receiving side more accurate.

[0007]

According to the present invention, on a transmitting side, a video signal processing circuit and a first chroma key color detection for detecting a chroma key color signal from a video signal output from the video signal processing circuit. Circuit and the first chroma key color detection circuit detects a chroma key color from the output video signal of the video signal processing circuit, the video signal has a desired hue,
In order to determine whether the color is saturation and correct the error, first determination control means for applying a hue and saturation control signal to the video signal processing circuit, and the first chroma key color detection circuit are also provided. When a chroma key color is detected from the output of the signal processing circuit, a means for inserting the back color signal from the color generator into the output of the video signal processing circuit is provided,
On the receiving side, the video signal demodulation circuit, the second chromakey color detection circuit for detecting a chromakey color signal from the output video signal from the demodulation circuit, and the second chromakey color detection circuit are used for video signal processing. When a chroma key color is detected from the output of the circuit, it is determined whether the video signal has a desired hue and saturation, and a hue and saturation control signal is given to the video signal processing circuit to correct the error. Second determination control means and means for inserting the back color signal from the color generator into the output of the video signal demodulation circuit when the chroma key color detection circuit detects the chroma key color from the output of the video signal demodulation circuit. It is a system characterized by having.

[0008]

By the above means, the basic signals for detecting the chroma key color on the transmitting side and the receiving side can be unified by the first and second judgment control means, and the detection error of the chroma key color is coded. This can be prevented from becoming impossible due to the band compression characteristics of the above. Further, even if there are a plurality of transmitting and receiving sides, automatic adjustment is possible between the communication devices, which eliminates the need for operator adjustment work.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment of the present invention. Reference numeral 22 denotes a video camera for picking up an image of a subject 21 with a chromakeyback as a back, and outputting the output of the chromakeyer 100 on the transmitting side.
(Described in detail in FIG. 2). The video signal in which the chroma key color is inserted in the chroma key back area in the chroma keyer 100 on the transmission side is band-compressed by the codec 23 and sent to the network 24. The signal from the network 24 is input to the codec 25 on the receiving side. The video signal decoded here is the receiving chromakeyer 20.
0 (described in detail in FIG. 3), the chroma key back area is detected and replaced with the background video signal prepared on the receiving side. The video signal thus obtained is supplied to the monitor 26.

FIG. 2 shows the transmitting chroma keyer 100 in detail.

The video signal from the video camera 22 is input to the video signal processing circuit 101. Here, the hue and saturation are adjusted by the hue and saturation adjustment data from the control circuit 104. The adjusted video signal is input to the switching circuit 103, the control circuit 104, and the chroma key color detection circuit 102. Chroma key color detection circuit 10
2 detects the chroma key back color signal. The detection signal (0 or 1) from the chroma key color detection circuit 102 is supplied to the control terminals of the control circuit 104 and the switching circuit 103. The switching circuit 103, when the detection signal is input,
The back color data from the color generator 105 is inserted into the video signal from the video signal processing circuit 101 and output. That is, the chroma key back area in the video signal is replaced with the color data from the color generator 105.

Further, the hue and saturation of the chroma keyback photographed by the video camera 22 may be different from the original value due to the influence of the lighting condition and the replacement process cannot be performed correctly at that time. In order to prevent this, for example, a detection area can be set in advance such as a fixed area on the upper left side or a fixed area on the upper right side (set to an area where there is a high probability that a back color exists). The control circuit 104 determines whether the video signal (chroma keyback color signal) when the detection signal is input has a desired hue and saturation, and detects the error. When this error is detected, the control circuit 104 controls the video signal processing circuit 101 to automatically adjust the hue and saturation in the direction in which the error is reduced. This makes it possible to associate the detection signal with the desired hue and saturation.

The output video signal of the switching circuit 103 is input to the codec 23, band-compressed, and sent to the network.

The control circuit 104 can input the back color detection data to the codec 23 and transmit it to the receiving side. This back color detection data is stored in the chroma key color detection circuit 102 for comparison or as the same memory data. In other words, the chroma key color detection circuit 102 detects the back color data, if any, in the video signal output from the video signal processing circuit 101 and obtains a detection signal, but the same operation as this operation is performed. In order for the receiving side to perform the same, it is necessary to transmit the same back color detection data to the receiving side.

FIG. 3 shows the receiving chroma keyer 200 in detail.

The signal from the network is input to the input terminal 20.
It is input to the codec 25 via 1. here,
The band of the transmitted video signal is restored and the demodulation circuit 203
Is supplied to. The transmitted back color detection data is also restored and input to the control circuit 204. The control circuit 204 sets the back color detection data in the chroma key color detection circuit 205.

The video signal demodulated by the demodulation circuit 203 is
It is input to the control circuit 204, the chroma key color detection circuit 205, and the switching circuit 206. Chroma key color detection circuit 205
Detects the chroma key back color signal. The detection signal from the chroma key color detection circuit 205 is supplied to the control terminals of the control circuit 204 and the switching circuit 206. Switching circuit 2
Reference numeral 06 denotes the demodulation circuit 203 when the detection signal is input.
A background video signal for synthesis is inserted into the output of. The background video signal is output from the background video signal source 207. As a result, the switching circuit 206 obtains a video signal in which the background video signal is combined with the background of the subject sent from the transmission side, and is supplied to the monitor.

On the other hand, using the detection signal obtained from the chroma key color detection circuit 205 and the video signal, the control circuit 204
Determines whether the back color signal matches a predetermined hue and saturation, and detects the error. When there is this error, the control circuit 204 gives hue and hue control data to the color control circuit included in the demodulation circuit 203, and controls so that the back color signal has a predetermined hue and saturation. The period for detecting the error is also set in advance, and is a predetermined detection region (determined as a region in which the back color is highly likely to exist) such as an upper left fixed region or an upper right fixed region on the screen.

By doing so, the hue and saturation of the back color area match those of the transmitting side, the back color detection accuracy in the video area is good, and the background video signal can be accurately inserted. In the conventional system, the back color may not be accurately detected when an error occurs in hue, saturation, etc. due to the codec band compression characteristic or the like. However, this system eliminates this.
In addition, when there are multiple transmitters and receivers via the network, it is necessary to eliminate the back color detection error due to the difference in transmission characteristics in the combination, but this system automatically Since it is controlled, such work is unnecessary, and it becomes possible to easily add transmitters and receivers.

In the above embodiment, it has been described that the back color detection data is transmitted from the transmitting side to the receiving side separately from the video signal. The point is that the detection data on the transmission side and the detection side may be the same, and the transmission timing is not limited in time, so various embodiments are possible as the transmission method. A plurality of types of detection data may be prepared in advance on the receiving side, and the switching control signal may be transmitted from the transmitting side. Further, although it has been described that there is a detection period of the back color signal (determined in a region where the probability that the back color exists is high), this period setting signal may be transmitted from the transmission side to the reception side. This is because the area where the back color exists may change depending on the subject.

According to the above system, as the detection period of the back color detection data, for example, a predetermined detection region (determined in a region in which there is a high probability that the back color exists)
I explained that. However, the present invention is not limited to this, and the back color signal for reference is displayed in a specific area (outside the display area on the receiving side as shown on the transmitting side monitor 31 in FIG. 4A (see FIG. 4B). Reference)), and the reference back colors C1, C2, and C3 may be referred to in this area to detect the error information of the hue and the saturation. The average error of these may be detected by inserting a plurality of types of back color signals.

[0023]

As described above, according to the present invention, when a plurality of chromakeyers on the transmitting side and the receiving side are connected by a network, they are not affected by the transmission characteristics of the communication system path and the fluctuations of the transmission characteristics occur. Accordingly, the back color signal detection operation can be automatically adjusted, and the switching operation for chroma key composition between the transmitting side and the receiving side can be made more accurate.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention.

FIG. 2 is a block diagram specifically showing the chroma keyer on the transmitting side of FIG.

FIG. 3 is a block diagram specifically showing a chroma keyer on the receiving side in FIG.

FIG. 4 is a diagram showing a display example of a monitor for explaining another embodiment of the present invention.

FIG. 5 is an explanatory diagram showing a conventional chroma key composition system.

[Explanation of symbols]

22 ... video camera, 23, 25 ... cordic, 24
... network, 26 ... monitor, 100 ... transmission side chroma keyer, 101 ... video signal processing circuit, 102, 205 ...
Chroma key detection circuit, 103, 206 ... Switching circuit, 10
4, 204 ... Control circuit, 203 ... Demodulation circuit, 207 ... Composition background image signal source.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hideji Kawakubo, 1-6, Uchiyuki-cho, Chiyoda-ku, Tokyo Nihon Telegraph and Telephone Corporation (72) Inoue, Mineo Masamitsu 1-6, Uchiyuki-cho, Chiyoda-ku, Tokyo No. Japan Telegraph and Telephone Corporation

Claims (3)

[Claims] 1. In a communication system in which a transmitting side and a receiving side are connected by a network, the transmitting side detects a video signal processing circuit and a chroma key color signal from a video signal output from the video signal processing circuit. And a first chroma key color detection circuit that detects a chroma key color from the output video signal of the video signal processing circuit, and determines whether the video signal has a desired hue and saturation. Then, in order to correct the error, the first determination control means for giving a hue and saturation control signal to the video signal processing circuit and the first chroma key color detection circuit are also connected to the chroma key from the output of the video signal processing circuit. When a color is detected, a back color signal from a color generator is inserted into the output of the video signal processing circuit.
And a second demodulation circuit for the input video signal, a second chromakey color detection circuit for detecting a chromakey color signal from the output video signal from the demodulation circuit, and the second circuit. When the chroma key color detection circuit of detects the chroma key color from the output of the video signal processing circuit, the output video signal has a desired hue,
In order to determine whether it is saturation and correct the error, there is provided second determination control means for applying a hue and saturation control signal to the video signal processing circuit, and also the chroma key color detection circuit is used for the video signal demodulation circuit. And a second control means for inserting a background video signal into the output of the video signal demodulation circuit when a chromakey color is detected from the output of the chromakey synthesis system. 2. The chroma key color signal detection from the transmitting side to the receiving side in order to store the same data for detecting the chroma key color signal of the first chroma key color detecting circuit in the second chroma key color detecting circuit. 2. The chroma key composition system according to claim 1, further comprising a transmission means for transmitting the use data. 3. The first and second control means, when a chroma key color is detected, a determination period for determining whether or not the output video signal has a desired hue and saturation is a preset period. The chroma key composition system according to claim 1, wherein: