JP2000261721A - Video composite device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video composite circuit that avoids failure in producing a flat KEY signal due to a difference from a frequency band of a luminance signal and a color difference signal when the KEY signal for compositing television pictures according to a 4:2:0:p video signal format and failure in a missing output when the picture is composited by using the video signal and its KEY signal. SOLUTION: A KEY generating video signal is separated by a Y/C separation circuit 1, a rearrangement circuit 2 rearranges a luminance signal according to a 4:2:0:p video signal format and interpolation circuits 3, 4 to provide the same band as that of the luminance signal to the color difference signal are provided. An output of the rearrangement circuit 2 and the interpolation circuits 3, 4 is given to a KEY generating circuit 8, which generates a television picture composite KEY signal. The obtained KEY signal is processed by a multiplexer circuit 9 according to the 4:2:0:p video signal format and the processed signal is given to a mixer circuit 11, where the signal is composited with the actual video signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video synthesizing apparatus, and more particularly to a method for synthesizing a plurality of images of a special effect video synthesizing apparatus for television used in a video sub-adjustment apparatus (production switcher) of a television broadcasting station or the like. The present invention relates to a super / chroma key / wipe synthesizing device.

[0002]

2. Description of the Related Art Recent television broadcasting stations and the like often use a video synthesizing apparatus. FIG. 5 is a block diagram showing a conventional example of a video synthesizing apparatus. This video synthesizing device includes a Y / C separation circuit 1, a KEY generation circuit 8, and a mixer circuit 11.

The Y / C separation circuit 1 receives a video signal input a for KEY generation, and the Y / C separation circuit 1
A signal (brightness signal) b, a CB signal (blue color difference signal) c, and a CR signal (blue color difference signal) d. These three types of signals b, c and d are input to the KEY generation circuit 8. This KEY generation circuit 8 has a super / chroma key /
A KEY signal 1 for screen synthesis such as a wipe is generated. The mixer circuit 11 outputs the KEY signal 1 and the mixer circuit 11
O, p, which are two video signals A and B input to
Are synthesized and output to an output terminal as a synthesized signal q.

FIG. 6 shows a block diagram of a typical mixer circuit 11. The mixer circuit 11 includes the multiplier 1
2, 13, adder 14 and inverting circuit (inverter) 15
It is composed of The video signals A and B are input to the multipliers 12 and 13, respectively, and the KEY signal for image synthesis and a signal obtained by inverting the phase of the KEY signal by the inverting circuit 15 are input to the multipliers 12 and 13.
The outputs of both multipliers 12 and 13 are input to adder 14, from which a combined video signal is obtained.

The operation of the mixer circuit 11 of FIG. 6 will be described with reference to the example of FIG. The video signal A has a short diagonal screen as shown in FIG. 7, and the video signal B has a fine crossbar screen as shown in FIG. It is also assumed that the KEY signal for image synthesis has a black star shape on a white background as shown in FIG. The KEY signal for image synthesis is composed of only a luminance signal (does not include a color difference component), and can have an arbitrary shape such as a character shape or a human shape.

The multiplier 12 multiplies the video signal A (FIG. 7) by the image synthesizing KEY signal (FIG. 7), and the output signal thereof is, as shown in FIG.
The video signal A is included outside the star, which is the white part of the signal, and the star remains dark. On the other hand, the multiplier 13
The video signal B (of FIG. 7) and the KEY signal for image synthesis (FIG. 7)
) Is multiplied by the inverted signal (of FIG. 7). Therefore, as shown in FIG. 7, the output signal of the multiplier 13 is dark outside the star shape, and the video signal B is included in the star shape. Finally, the adder 14 synthesizes the images of FIG. 7 and FIG. 8 so that the video signal A is outside the star as shown in FIG.
A composite video including the video signal B within the star is obtained. This image synthesis processing is represented by the following equation. Video signal A × key for synthesizing image + video signal B × (1
-KEY signal for image synthesis)

[0007]

However, in the above-mentioned conventional video (or image) synthesizing apparatus, video synthesizing is always performed in the same system regardless of the formats of the input video signal and the video signal for KEY generation. . EDTV (Extended Definition) with improved image quality in recent years
2nd generation EDTV-2, in which the aspect ratio (the aspect ratio of the image) is increased from 4: 3 to 16: 9, has been put to practical use. A video synthesizing apparatus that also supports the 4: 2: 0: p format used in the EDTV-2 is desired. However, the conventional video synthesizing apparatus cannot cope with the 4: 2: 0: p video signal format.

Here, the 4: 2: 0: p video signal format is a signal format in which a luminance signal is sampled by sequential scanning, and a color difference signal is sampled by interlaced scanning.
The number of samplings in one horizontal period (one line scanning period) is 1,440 samples of a luminance signal, of which Y * is 72
0 samples and Y * 'are composed of 720 samples. There are 720 color difference signals, of which 360 are CB * and 360 are CR *. In addition, there is blanking data, which is composed of 128 samples (including SAV / EAV signals). Therefore, the total number of samples in one horizontal scanning period is 2,28.
It becomes 8. Here, the SAV / EAV signal is 4: 2:
0: A signal that is always present in the p video signal format, and identifies the beginning and end of the video signal, field identification, field blanking identification, SAV / EA.
This signal indicates information such as V identification.

FIG. 8 shows a configuration diagram of the multiplexing of the 4: 2: 0: p video signal format described above. FIG. 9 shows a timing diagram of the data format of the 4: 2: 0: p video signal format and the analog video signal.

In the conventional circuit, a video signal format in which both the luminance signal and the color difference signal are sampled by sequential scanning or interlaced scanning is possible.
When the image synthesis is performed by inputting the 2: 0p video signal format, the band of the color difference signal of the line N + 1 shown in FIG. 8 is lacking. Is generated, and there is a problem that a flat image cannot be obtained as an actually synthesized image.

An object of the present invention is to provide a video synthesizing apparatus for generating a flat video synthesizing KEY signal by setting the same band for a luminance signal and a color difference signal in a 4: 2: 0: p video signal format. is there.

[0012]

In order to solve the above-mentioned problems, a video synthesizing apparatus according to the present invention employs the following characteristic configuration.

(1) In a video synthesizing apparatus including a Y / C separation circuit, a KEY generation circuit and a mixer circuit,
A video synthesizing apparatus, comprising: a rearrangement circuit for rearranging the separated luminance signals on the output side of the C separation circuit; and an interpolation circuit for the separated synthesized signal, and performs video synthesis in a 4: 2: 0: p video signal format.

(2) A selection circuit for selecting a luminance signal and a color difference signal from the Y / C separation circuit and a luminance signal and a color difference signal from the rearranging circuit and the interpolation circuit is provided. The video synthesizing apparatus according to the above (1), wherein the switching is selected by a mode switching signal.

(3) A multiplexing circuit and a selecting circuit are provided on the output side of the KEY generating circuit, and in the case of 4: 2: 0: p video signal format, the multiplexing is performed by the multiplexing circuit. apparatus.

(4) The video synthesizing apparatus according to (1), wherein the interpolation circuit obtains an average value of signal data adjacent to the color difference signal and performs interpolation.

(5) The video of (1), (2), (3) or (4) above, which shares the 4: 2: 0: p video signal format and the D2 digital composite / D1 digital component / HDTV video signal format. Synthesizer.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of a preferred embodiment of a video synthesizing apparatus according to the present invention will be described below in detail with reference to FIGS.

First, a block diagram of a preferred embodiment of the video synthesizing apparatus of the present invention will be described with reference to FIG. The same reference numerals are used for the constituent elements corresponding to the constituent elements of the conventional video synthesizing apparatus described above with reference to FIG.

The video synthesizing apparatus shown in FIG. 1 comprises a Y / C separation circuit 1, a rearrangement circuit 2, interpolation circuits 3, 4, a selection circuit 5,
6, 7, key generation circuit 8, multiplexing circuit 9, selection circuit 10
And a mixer circuit 11.

The video signal a for KEY generation is input to the Y / C separation circuit 1, and the luminance signal b, the signal c of the color difference signal CB, and the signal d of the color difference signal CR are separated and generated as in the conventional circuit. The signal b is rearranged by the rearrangement circuit 2 in the order of Y * and Y * '(sampled data of the line N and the line N + 1) as shown in FIG. 3, and the signal e is output. On the other hand, signals c and d are interpolated by interpolation circuits 3 and 4, respectively, as shown in FIG. For example, they are CB *, CB * #, and CB #. As CB #, a value obtained by adding CB * and CB # and dividing by two (ie, averaging) is inserted. Also, CB
* ′, CB * # ′, and CB # ′ are obtained by adding the CBs of the line N and the line N + 2 and dividing by 2 in order to insert the color difference signal also into the line N + 1 (to have the same band as the luminance signal). You are inserting a value.

The CR signal performs the same processing as that of the above-mentioned CB, and becomes CR *, CR * #, CR #. CR * #
Means that a value obtained by adding CR * and CR # and dividing by 2 is inserted. CR * ', CR * #', and CR # 'add CR of line N and line N + 2 and divide by 2 to insert a color difference signal into line N + 1 (to have the same band as the luminance signal). The inserted value is inserted.

The selection circuit 5 switches and selects the signal b and the signal e with the video signal mode switching signal h, and outputs the signal i.
Is sent to the KEY generation circuit 8. Similarly, the selection circuit 6 switches and selects the signal C and the signal f with the video signal mode switching signal h, and sends the signal C to the KEY generation circuit 8 as the signal j. Further, the selection circuit 7 switches and selects the signal d and the signal g with the video signal mode switching signal h.
It is sent to the Y generation circuit 8.

The KEY generation circuit 8 is a circuit for generating a KEY signal for synthesizing a television image, and generates, for example, a super key, a chroma key, a wipe key, and the like. This K
The KEY signal for television image synthesis output from the EY generation circuit 8 is defined as a signal l, and the multiplexing circuit 9 and the selection circuit 10
Enter each. The multiplexing circuit 9 converts this signal 1 into the signal shown in FIG.
The signal format is changed as shown in (A) to (C) and input to the selection circuit 10 as the signal m. Selection circuit 1
In the case of 0, the signal 1 and the signal m described above are switched and selected by the video signal mode switching signal h and input to the mixer circuit 11 as the signal n. The mixer circuit 11 outputs the video signal A (signal o) and the video signal B as described above with reference to FIG.
(Signal p) is video-combined with the above-mentioned signal n and output as signal q.

Next, the operation of the video synthesizing apparatus of FIG. 1 will be described with reference to the timing chart of FIG. In the KEY generation video signal input (signal a) input to the Y / C separation circuit 1, a luminance signal (Y signal) and a color difference signal (CB signal / CR signal) are multiplexed. FIG. 2A shows the multiplexed Y / C.
Indicates a signal. This signal is separated by the Y / C separation circuit 1 and separated and output into a Y signal in FIG. 2B, a CB signal in FIG. 2C, and a CR signal in FIG. 2D. As for the CB signal / CR signal, there is a signal called CB12 or CR12. In order to make these signals CB12 and CR12 the same as the band of the luminance signal in the horizontal period, the signal data obtained by the following formula is lost. That is, CB12 = (CB1 + CB2) / 2 CB12 = (CR1 + CR2) / 2, and the average value of the values before and after the signal data to be inserted is obtained.

On the other hand, the operation of the rearrangement circuit 2 is executed according to the timing chart shown in FIG. In the video signal format of 4: 2: 0: p signal, since the luminance signal exists (progressive) on line N and line N + 1 as shown in FIG.
+1 is rearranged before and after the horizontal period.

Next, the interpolation circuits 3 and 4 will be described. Since the color difference signal exists only on the line N as shown in FIG. 8, the band for the luminance signal on the line N + 1 is insufficient. To compensate for this, at the same timing as the line N + 1 processed by the rearranging circuit 2, a color difference signal obtained by, for example, the following formula is inserted. That is, CB1 ′ = (CB1 of line 1 + CB1 of line 3) /
2 CB12 ′ = (CB1 of line 1 + CB1 of line 3
2) / 2 CR1 '= (CR1 of line 1 + CR1 of line 3)
/ 2 CR12 '= (CR1 of line 1 + CR1 of line 3
2) / 2, and the average between the lines is calculated as the line N
Insert at position +1.

The selection circuits 5, 6, 7 use either the system of the 4: 2: 0: p video signal format or another video signal format (D2 digital composite, D1 digital composite, HDTV, etc.). It is a circuit that determines whether to do.

The configuration and operation of the KEY generation circuit 8 are well known to those skilled in the art and are not the gist of the present invention, so that detailed description is omitted here.

In this embodiment, the super key signal, the chroma key signal and the wipe key signal are 4: 2: 0:
At the time of the p video signal format, the output is performed in a format as shown in FIG.

The multiplexing circuit 9 starts the formal 4: 2: 0:
This is a circuit for conversion to the same format as the p video signal format. Further, the mixer circuit 11 performs a synthesizing process of the video signal A and the video signal B using the KEY signal for image synthesis. The mixer circuit 11 itself may be a conventional circuit, and its configuration and operation are shown in FIGS.

The configuration and operation of the preferred embodiment of the video synthesizing apparatus according to the present invention have been described above in detail. However, the present invention should not be limited to only such specific examples, and those skilled in the art can easily understand that various modifications can be made as necessary.

[0033]

As will be understood from the above description, according to the video synthesizing apparatus of the present invention, by using the rearranging circuit, the interpolation circuit, the multiplexing circuit and the selecting circuit, 4: 2:
0: It is possible to cope with image synthesis in the p video signal format. Also, by setting the same band for both the luminance signal and the color difference signal, a flat KEY signal for screen synthesis can be generated, and by using this KEY signal, there is a practically remarkable effect that natural image synthesis becomes possible. .

[Brief description of the drawings]

FIG. 1 is a block diagram of a preferred embodiment of a video synthesizing apparatus according to the present invention.

FIG. 2 is an operation timing chart of a Y / C separation circuit used in the video synthesizing apparatus of FIG. 1;

FIG. 3 shows a rearrangement circuit and CB /
It is an output timing chart of CR interpolation circuit.

FIG. 4 is an output timing chart of a KEY generation circuit and a multiplex circuit of the video synthesizing apparatus of FIG. 1;

FIG. 5 is a block diagram of a conventional video synthesizing apparatus.

FIG. 6 is a detailed block diagram of the mixer circuit of FIG. 5;

FIG. 7 is an explanatory diagram of signal processing of each unit of the mixer circuit of FIG. 6;

FIG. 8 is an explanatory diagram of multiplexing of a 4: 2: 0: p video signal format.

FIG. 9 is a timing chart of a data format of a 4: 2: 0: p video signal format and an analog video signal.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Y / C separation circuit 2 Rearrangement circuit 3, 4 Interpolation circuit 5, 6, 7, 10 Selection circuit 8 KEY generation circuit 9 Multiplex circuit 11 Mixer circuit

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) GA32 GB01 HA01 JA02 KE01 KE02 KE03 KE16 KG05 LA02

Claims (5)

[Claims] 1. A video synthesizing apparatus including a Y / C separation circuit, a KEY generation circuit, and a mixer circuit, wherein a rearrangement circuit for rearranging a luminance signal separated at an output side of the Y / C separation circuit, and a separated synthesis circuit. A video synthesizing apparatus, comprising: an interpolation circuit for interpolating a signal; and performing video synthesis in a 4: 2: 0: p video signal format. A selection circuit for selecting a luminance signal and a color difference signal from the Y / C separation circuit and a luminance signal and a color difference signal from the rearranging circuit and the interpolation circuit; 2. The video synthesizing apparatus according to claim 1, wherein switching is selected by a switching signal. 3. A multiplexing circuit and a selecting circuit are provided on the output side of the KEY generating circuit, and multiplexing is performed by the multiplexing circuit in the case of a 4: 2: 0: p video signal format. 5. The video synthesizing device according to 1. 4. The video synthesizing apparatus according to claim 1, wherein said interpolation circuit calculates and interpolates an average value of signal data adjacent to the color difference signal. 5. The 4: 2: 0: p video signal format and D
5. The video synthesizing apparatus according to claim 1, wherein the two digital composite / D1 digital component / HDTV video signal format are shared.