KR0127041B1 - Luminance and chrominance separation method and its apparatus - Google Patents

Abstract

Disclosed is a method and an apparatus to separate a brightness signal and a color signal from a composite image signal. The apparatus comprises a demodulator, a color-difference signal generator, a selection controller, a selector, a modulator and a brightness signal outputter. The demodulator demodulates the composite image signal by delay signals from the composite image signal. The color-difference signal generator filters the color-difference signal from the demodulator so that other color-difference signals are generated. The selection controller generates a selection signal according to correlation among the color-difference signals. The selector performs a soft switching to the color-difference signals by the selection signal, so that an optimized color-difference signal is outputted. The modulator outputs a color signal by modulating the optimized color-difference signal from the selector. Thereby, the frequency band is not full so that the manufacturing cost can be reduced, and accurate separation can be performed.

Description

Luminance / Color Signal Separation Method and Device

1 is a band distribution diagram of an NTSC composite video signal.

2 is a block diagram showing a luminance / color signal separation device using a conventional line comb filter.

3 is a block diagram showing a luminance / color signal separation device using a conventional adaptive line comb filter.

4 is a detailed block diagram of the selection controller shown in FIG.

5 is a block diagram showing a first embodiment of the luminance / color signal separation device according to the present invention;

6A and 6B are block diagrams showing first and second embodiments of demodulation means in FIG.

FIG. 7 is a block diagram showing an embodiment of the selection control section in FIG.

8A and 8B are block diagrams showing first and second embodiments of the selection section in FIG.

9A and 9B are block diagrams showing first and second embodiments of the modulator in FIG.

10 is a block diagram showing a second embodiment of the luminance / color signal separation device according to the present invention;

* Description of the symbols for the main parts of the drawings *

10: delay means 11, 12, 100, 130, 140: 1H delay unit

14,24: bandpass filter 16,21: lowpass filter

15, 19, 41c, 41d, 41f, 42c, 42d, 42f, 43c, 43d, 44c, 44d, 51, 53: Multiplier

17: 180 ° C. Delay 18,54: 90 ° C. Delay

20: demodulation means 21, 22, 23, 110, 120: demodulation unit

25,27: demodulator 26,28,55,56: code converter

30: selection control unit 40, 150: selection unit

37: (R-Y) correlation detection part 38: (B-Y) correlation detection part

37a, 37b, 38a, 38b, 60, 170: Subtractor 37e, 38e: Comparator

37c, 37d, 38c, 38d: Absolute value processor 50, 160: Modulator

41a, 41b, 41e, 42a, 42b, 42e, 43a, 43b, 44a, 44b, 52: adder

41g, 42g, 43e, 44e: Multiplexer 57: Modulator

The present invention relates to a method and apparatus for separating luminance / color signals of a composite video signal, and more particularly, to a method and apparatus for separating luminance / color signals using demodulated color signals.

The present invention can be applied to the present general color television system (NTSC, PAL, SECAM, etc.) on the same principle, but for convenience of explanation, a composite video signal of the NTSC television system will be described as an example.

The NTSC composite video signal is composed of a luminance signal, a color signal, and a synchronization signal, and the color signal is implemented as a quadrature modulation of the R-Y / B-Y or I / Q signal. To reproduce the original image from the composite signal having such a configuration

Firstly, a synchronization separation process for separating horizontal and vertical synchronization signals from a composite video signal;

Secondly, a luminance / color signal (Y / C) separation process for separating the luminance signal (Y) and the color signal (C) from the composite video signal;

Third, a color demodulation process of demodulating the color signal C into an R-Y / B-Y signal is necessary. The present invention relates to a second Y / C separation process using a third demodulated color signal (C).

1 is a diagram illustrating band distribution of a composite video signal.

In FIG. 1, description of the audio signal and the image carrier will be omitted. As shown in FIG. 1, the luminance signal Y has a signal band of about 4.3 MHz, and the color signals I and Q have bandwidths of 1.5 MHz and 0.5 MHz, respectively, around the color carrier frequency fsc.

If the composite video signal is V (t), the luminance signal is Y (t), and the color signal is C (t),

V (t) = Y (t) + C (t)... … … … … … … … … … … … … … … … … … … … … … … ①

Since C (t) is a quadrature-modulated signal of I (t) and Q (t),

C (t) = I (t) cos (2π fsct) + Q (t) sin (2π fsct)... … … … … … … … … … ②

to be. In this case, fsc is a carrier frequency of the color signal, which is 3.579545 MHz (about 3.58 MHz). In the NTSC system, between fsc and the frequency f _H of the horizontal synchronization signal

fsc = (455/2) f _H ... … … … … … … … … … … … … … … … … … … … … … … … ③

The relationship is established.

A method of using a filter may be discussed as a method of simply performing Y / C separation from a composite video signal having the configuration as shown in FIG. In other words, the luminance signal Y is separated using the low pass filter LPF, and the color signal is separated using the band pass filter BPF having a band around 3.58 MHz. In this method, it is difficult to expect a satisfactory image quality due to cross-talk of luminance / color signals occurring in a band of 2 MHz or more where the luminance signal Y and the color signal C are mixed.

2 is a block diagram showing a luminance / color signal separation device using a conventional line comb filter. The line comb filter method according to the block diagram shown in FIG. 2 is a T / C separation method that improves the Y / C separation method using the filter in FIG. 1, and the NTSC method signal for the color signal phase difference between horizontal scan lines is shown in FIG. As the essential characteristic in the description is omitted.

the composite video signal of the i-th horizontal scan line

V _i (t) = Y _i (t) + C _i (t)... … … … … … … … … … … … … … … … … … … … … … … ④

, The composite video signal of the (i + 1) th horizontal scan line

V _{i + 1} (t) = Y _{i + 1} (t) -C _{i + 1} (t)... … … … … … … … … … … … … … … … … … … … ⑤

Becomes

Therefore, the horizontal scan line can be delayed by one line (1H; 1H is the period of the horizontal scan line), and the luminance signal can be obtained by adding and calculating the scanning lines before and after, and subtracting the color signal. Such a device is called a line comb filter. The line comb filter method can obtain an improved image without cross-talk of luminance / color signals when the image is correlated vertically compared to the method of performing Y / C separation using a conventional filter. In the case of an image having little or no correlation, a hanging dot phenomenon occurs and image quality deteriorates.

FIG. 3 is a block diagram showing a luminance / color signal separation device using a conventional adaptive line comb filter. The Y / C separation method using the adaptive line comb filter shown in FIG. 3 is a line comb filter method shown in FIG. It is an improved method of separating Y / C. This method is mainly used for so-called digital comb filters or CCD comb filters that use digital signal processing, and the three-dimensional processing using frame memory (in addition to the two-dimensional processing in the vertical / horizontal space) is performed on the time axis processing. It is advantageous for two-dimensional Y / C separation because it is inexpensive and easy to implement.

The Y / C separation method using the adaptive line comb filter is as follows.

First, a composite video signal V currently input, a signal 1H delayed signal VH and a signal 2H delayed signal VHH are formed.

Secondly, a color signal (BOTTOM-1H) using the line comb filter using V and VH and a color signal (TOP-1H) using the line comb filter using VH and VHH are formed;

Third, depending on the correlation between V, VH and VHH, adaptively selects and outputs BOTTOM-1H or TOP-1H.

Accordingly, the image quality is improved by reducing the occurrence of a hanging dot by the third selective output.

The block diagram shown in FIG. 3 is a representative form of the adaptive line comb filter and includes a detection means 32 and a selection means 34. The detection means 32 includes 1H delay units 32a and 32b and subtractors 32c and 32d to generate line comb-filtered signals BOTTOM-1H and TOP-1H for 1H. The selection means 34 includes a selection controller 34a which determines whether the correlation between V, VH and VH, VHH is superior, and outputs the selection signal S, and BOTTOM-1H or TOP corresponding to the selection signal S. A multiplexer (MUX) 34b for selecting and outputting -1H, and a multiplier 34c for reducing and outputting the level of the signal input thereto to 1/2.

However, the Y / C separation combination that can be derived from V and VH and VHH

1) a color signal obtained by bandpass filtering VH,

2) the color signal (BOTTOM-1H) subjected to the line comb filter using V and VH,

3) the color signal (TOP-1H) subjected to the line comb filter using VH and VHH,

4) There may be four types of color signals (1H-COMB) that are subjected to 2H line comb filter using V, VH, and VHH. According to the state of a composite video signal, an optimal color signal or an optimal mixed color signal may be obtained. It becomes preferable.

FIG. 4 is a detailed block diagram of the selection control unit 34a shown in FIG. 3, by applying the current composite video signal, the 1H delayed signal, and the 2H delayed signal to each of the three low pass filters 1, 2, and 3, respectively. After extracting only the luminance signal, the subtractor 4 subtracts the luminance signal delayed by 1H from the current luminance signal, and the subtractor 5 subtracts the luminance signal delayed by 2H from the luminance signal delayed by 1H and passes through the absolute value processors 6 and 7, respectively. The comparator 8 compares the selection signal S with each other.

However, in this case, when there is a difference in the high frequency portion of the luminance signal, a wrong decision can be made, and there is a problem that a full-band band is required in generating the delay signal.

Accordingly, an object of the present invention is to provide a luminance / color signal separation method for separating a color signal and a luminance signal from a composite video signal using demodulated color signals.

Another object of the present invention is to provide a luminance / color signal separation device most suitable for realizing a luminance / color signal separation method using demodulated color signals.

In order to achieve the above object, the present invention provides a method of separating a luminance signal and a color signal from a composite video signal, wherein the composite video signal V and the composite video signal V are delayed by 1H (H is a horizontal scanning period). A demodulation process for demodulating by using a burst signal to separate the color difference signals (RY, BY) _V and (RY, BY) _VH and (RY, BY) _VHH from the signal VHH delayed by VH) and 2H, respectively; The color difference signals (RY) _V and (RY) _VH and (RY) _VHH , (BY) _V, and (BY) _VH and (BY) _VHH are each line-filtered color difference signals (RY) _BTM-1H and (BY) _BTM-1H , 2-line comb filtered color difference signal (RY) _TOP-1H and (BY) _TOP -1H, 2H comb filtered color difference signal (RY) _2H-COMB and (BY) _{2H-COMB respectively} Generating a color difference signal for generating; A correlation detecting step for detecting a correlation between the (RY) _V and (RY) _VH and (RY) _VHH and a correlation between the (BY) _V and (BY) _VH and (BY) _VHH ; The color difference signal ((RY) _BTM-1H , (RY) _TOP-1H , (RY) _2H-COMB ) and the color difference signal ((BY) _BTM-1H , (BY) _TOP-1H , (BY) _2H-COMB ) color difference signal output process for soft-switching each to output an optimal color difference signal; A color signal output process for outputting a color signal by modulating the color difference signal output in the color difference signal output process using a burst signal; And a luminance signal output process of subtracting the color signal outputted by correction delay to the 1H delayed composite image signal VH and outputting the same as a luminance signal.

In order to achieve the above object, the present invention provides a device for separating luminance and color signals from a composite video signal, wherein the composite video signal (V) and the composite video signal (V) are delayed by 1H and the signal (H) and 2H delay. Demodulation means for demodulating the received signal VHH using a burst signal, and color difference signals RY _V and (RY) _VH and (RY) _VHH , (BY) _V and (BY) output from the demodulation means. 1 line com-filtered chrominance signal (RY) _BTM-1H and (BY) _BTM-1H , 2 line com-filtered chrominance signal (RY) _TOP-1H and (BY) _TOP , respectively using _VH and (BY) _{VHH -1H} , a color difference signal generating means for generating 2H comb filtered color difference signals (RY) _2H-COMB and (BY) _2H-COMB , respectively, and the color difference signals (RY) _V and (RY) _VH and (RY) _VHH A selection control means for detecting a correlation between and (BY) _V and a correlation between (BY) _VH and (BY) _VHH to generate a selection signal; Color difference signal ((RY) _BTM-1H , (RY) _TOP-1H , (RY) _2H-COMB ) and the color difference signal ((BY) _BTM-1H , (BY) _TOP-1H , (BY) _2H-COMB ) (B) selecting means for outputting an optimal color difference signal by soft-switching), modulation means for outputting a color signal by modulating the color difference signal output from said selecting means using a burst signal, and said 1H delayed composite video signal And luminance signal output means for subtracting the color signal outputted by correction delay to VH and outputting it as a luminance signal.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

5 is a block diagram showing an embodiment of a luminance / color signal separation device according to the present invention.

The configuration of the block diagram shown in FIG. 5 includes delay means 10 for delaying the composite video signal by 1H and composite video signal V and 1H output from the delay means 10 using a burst signal. Demodulation means 20 for demodulating the delayed signal VH and the 2H delayed signal VHH, respectively, to generate the (RY, BY) chrominance signal, and the (RY, BY) _V , ( RY, BY) _VH , (RY, BY) _{VHH The} color difference signal is inputted, the selection control unit 30 for detecting the correlation and outputting the selection signal S, and the selection signal S of the selection control unit 30. Selector 40 for selecting and outputting the optimal color difference signal among the (RY, BY) _V , (RY, BY) _VH and (RY, BY) _VHH color difference signals output from the demodulation means 20 And a modulator 50 for outputting the color signal C by modulating the (RY, BY) color difference signal output from the selector 40 and a 1H delayed signal VH output from the delay means 10. Color signal which is an output signal of the negative unit 50 By subtracting (C) comprises a subtracter 60 for outputting a luminance signal (Y).

6A and 6B are block diagrams showing the first and second embodiments of the demodulation means 20 in FIG. 5, and FIG. 6A is a first embodiment of the demodulation means 20, showing a basic example of AM demodulation. Therefore, the configuration and operation will be omitted here.

6 shows a second embodiment of the demodulation means 20. The band pass for band-pass filtering the composite video signal V or the 1H delayed signal VH or the 2H delayed signal VHH to output the color signal C is shown in FIG. A first demodulator 25 for demodulating the color signal output from the bandpass filter 24 using a filter BPF 24 and a burst locked fsc (about 14 MHz) as a clock signal, and fsc A second demodulator 27 for demodulating the color signal output from the band pass filter 24 and a code converter for converting the code of the signal output from the first demodulator 25 using the inverted signal as a clock signal ( 26, and a code converter 28 for converting the code of the signal output from the second demodulator 27.

Here, in a system using a clock signal of 4fsc (about 14 MHz) that is burst locked, color demodulation becomes very simple.

This can be summarized as follows.

C (t) = E _(RY) COS2πfsct + E _(BY) SIN2πfsct

If you substitute t = n / 4fsc,

C (n / 4fsc) = C (n) = E _(RY) (n) COSπn / 2 + E _(BY) (n) SINπn / 2

Becomes Therefore, C (0) = E _RY , C (1) = E _BY , C (2) =-E _RY , C (3) =-E _BY , C (4) = E _RY , and the color signal is (RY). ), (BY),-(RY), and-(BY) are outputted repeatedly, so you can change the sign and latch it.

FIG. 7 is a block diagram showing an embodiment of the selection control unit 30 in FIG. 5, and detects the correlation between (RY) _V and (RY) _VH and (RY) _VHH and selects the selection signal X. FIG. A correlation between the generated (RY) correlation detection unit 37 and (BY) _V and (BY) _VH and (BY) _VHH to generate the selection signal Y to the (BY) correlation detection unit 38. made becomes, (RY) correlation detection unit 37 (RY) _V in (RY) and a first subtracter (37a) for subtracting _VH, a second subtractor (37b for subtracting the (RY) _VHH the (RY) _VH ), A first absolute value processor 37c for taking the absolute value of the output CO1 _RY of the first subtractor 37a, and a first value for taking the absolute value of the output CO2 _RY of the second subtractor 37b. The absolute value processor 37d compares the output AR-Y of the first absolute value processor 37c with the output B _RY of the second absolute value processor 37d so that A _RY is greater than B _RY . It comprise a comparator (37e) for determining a selection signal (X), (bY) correlation detector 38 (bY) to the _V (BY) of a third subtracter (38a) and (BY) the fourth subtracter (38b) and an output (CO1 _BY) of the third subtractor (38a) for subtracting the (BY) _VHH to the _VH for subtracting the _VH Third absolute value processor 38c for taking absolute values, fourth absolute value processor 38d for taking absolute values of output CO2 _BY of fourth subtractor 38b, and third absolute value processor 38c. ) made up of the output (a _bY) a comparator (38e) and for determining the output (B _bY) selection signal (Y) to the _bY a is greater than the B _bY compares the absolute value of the fourth processor (38d).

8A and 8B are block diagrams showing the first and second embodiments of the selector 40 in FIG. 5, and FIG. 8A is a first embodiment of the selector 40, (RY) _V. FIG. And a first multiplier 41a for adding (RY) _VH , and a first multiplier 41c for outputting (RY) _BTM-1H by level converting the output of the first adder 41a by 1/2; , A third adder 41b for adding (RY) _VH and (RY) _VHH , and a third for outputting (RY) _TOP-1H by level shifting the output of the third adder 41b by 1/2. Level shift the output of the multiplier 41d, the output of the first multiplier 41c, and the output of the fifth adder 41e and the fifth adder 41e to add the output of the third multiplier 41d by 1/2. to that of the fifth multiplier (41f) for outputting the _{(RY) 2H-COMB, a} RY this case is larger than B _RY, a _bY is greater than B _bY selecting the (RY) _BTM-1H, and a _RY is B smaller than _{RY, BY} a is smaller than B _BY selecting the (RY) _TOP-1H, and, a is smaller than B _{RY RY, BY} a is than B keugeo _BY , A _RY is greater than B _RY, A _BY more first multiplexer (41g) and, A _RY is greater than B _RY, A _BY the B _BY selecting and outputting when (RY) _2H-COMB smaller than B _BY If large, select (BY) _BTM-1H ; if A _RY is less than B _RY ; if A _BY is less than B _BY , select (BY) _TOP-1H ; if A _RY is less than B _RY , and A _BY is B _When larger than _BY or A _RY is greater than B _RY and A _BY is smaller than B _BY , the second multiplexer 42g selects and outputs (BY) _2H-COMB .

8B shows a second embodiment of the selector 40. The output of the second adder 42a and the second adder 42a for adding (BY) _V and (BY) _VH is halved. Outputs the second multiplier 42c for converting and outputting (BY) _BTM-1H , the fourth adder 42b for adding (BY) _VH and (BY) _VHH , and the output of the fourth adder 42b. A fourth multiplier 42d for outputting (BY) _TOP-1H by level conversion to 1/2, and a sixth adder for adding the output of the second multiplier 42c and the output of the fourth multiplier 42d ( 42e), the sixth multiplier 42f for outputting (BY) _2H-COMB by level shifting the output of the sixth adder 42e by 1/2, and when A _RY is greater than B _RY (RY) _{BTM If -1H} is selected, if A _RY is smaller than B _RY , select (RY) _TOP-1H to output the third multiplexer (43e), and if A _BY is larger than B _BY , select (BY) _BTM-1H . , When A _BY is smaller than B _BY , the fourth multiplexer 44e selects and outputs (BY) _TOP-1H .

9A and 9B are block diagrams showing the first and second embodiments of the modulator 50 in FIG. 5, and FIG. 9A is a first embodiment of the modulator 50, showing a basic example of AM modulation. Therefore, the configuration and operation will be omitted here.

FIG. 9B is a second embodiment of the modulator 50, and includes a code converter for code conversion of the color difference signal RY output from the first multiplexer 41g and the second multiplexer 42g, and BY. 55, 56, and (RY), (BY), and-(RY),-(BY), and a burst signal, and a modulator 57 for modulating the color signal.

FIG. 10 is a block diagram showing a second embodiment of the luminance / color signal separation apparatus according to the present invention, in which the composite video signal V and the composite video signal V output from the 1H delay unit 100 are delayed by 1H. Demodulators 110 and 120 for demodulating by using a burst signal to separate the color difference signals RY, BY _V and (RY, BY) _VH from (VH), and (RY) output from the demodulator 120 (BY) _VH (RY) _V and (RY) _VH and (RY) _VHH , (BY) _V and (BY) _{VH to} delay _VH by 1H, respectively, to generate (RY, BY) _VHH . and (bY) using the _VHH each first line comb filtered chrominance signal (RY) _BTM-1H and the (bY) _BTM-1H, each two-line comb filtering the color difference signals (RY) _TOP-1H and the (bY) _{TOP- 1H} , 2H comb filtered color difference signals (RY) _2H-COMB and (BY) _2H-COMB , respectively, so that the correlation between (RY) _V and (RY) _VH and (RY) _VHH and (BY) _V and Detects the correlation between (BY) _VH and (BY) _VHH and _uses the correlation RY) _BTM-1H , (RY) _TOP-1H , (RY) _2H-COMB ) and color switching signals ((BY) _BTM-1H , (BY) _TOP-1H , (BY) _2H-COMB ) A selector 150 for outputting an optimal color difference signal, a modulator 160 for outputting a color signal by modulating the color difference signal output from the selector 150 using a burst signal, and a 1H delayed composite A subtractor 170 subtracts the color signal outputted by correction delay to the image signal VH and outputs the color signal as a luminance signal.

As described above, in the method and apparatus for separating luminance / color signals according to the present invention, the luminance / color signal separation is performed using a demodulated color signal, i.e., a color difference signal having a small frequency band, thereby eliminating the need for a full band frequency band, thereby reducing costs There is an effect that accurate luminance / color signal separation can be performed.

Claims (19)

A method of separating a luminance signal and a color signal from a composite video signal, the method comprising delaying the composite video signal (V) and the composite video signal (V) by 1H (H is a horizontal scanning period) and a signal by delaying 2H ( Demodulation process using a burst signal to separate the color difference signals (RY, BY) _V and (RY, BY) _VH and (RY, BY) _VHH from _VHH , respectively; The color difference signals (RY) _V and (RY) _VH and (RY) _VHH , (BY) _V, and (BY) _VH and (BY) _VHH are each line-filtered color difference signals (RY) _BTM-1H and (BY) _BTM-1H , 2-line comb filtered color difference signal (RY) _TOP-1H and (BY) _TOP-1H , 2H comb filtered color difference signal (RY) _2H-COMB and (BY) _2H-COMB , respectively Generating a color difference signal for generating; A correlation detecting step for detecting a correlation between the (RY) _V and (RY) _VH and (RY) _VHH and a correlation between the (BY) _V and (BY) _VH and (BY) _VHH ; The color difference signal ((RY) _BTM-1H , (RY) _TOP-1H , (RY) _2H-COMB ) and the color difference signal ((BY) _BTM-1H , (BY) _TOP-1H , (BY) _2H-COMB ) color difference signal output process for soft-switching each to output an optimal color difference signal; A color signal output process for outputting a color signal by modulating the color difference signal output in the color difference signal output process using a burst signal; And a luminance signal output process of subtracting the color signal outputted by correction delay to the 1H delayed composite image signal (VH) and outputting the same as a luminance signal. 2. The method of claim 1, wherein the demodulation process comprises: a color signal separation process for separating color signals by bandpass filtering on the V, VH, and VHH, respectively; Generating a color difference signal (R-Y, B-Y,-(R-Y),-(B-Y)) from the color signal using a clock signal composed of a burst locked frequency and an inverted clock signal; And a color difference signal output process for outputting the color difference signals RY and BY by latching and sign-converting the corresponding color difference signals with respect to the color difference signals RY, BY,-(RY) and-(BY). Method of separating luminance / color signal. 3. The method of claim 2, wherein the clock signal has a frequency of 4fsc (fsc: burst signal frequency). The method of claim 1, wherein the color difference signal generation process is performed by using the (RY) _V and (RY) _VH and the (BY) _V and (BY) _VH , respectively, by the one line com-filtered color difference signal (RY) _BTM-1H and (BY) procedure for generating _BTM-1H ; And (RY) _VH and (RY) _VHH , (BY) _VH and (BY) _VHH , respectively, to generate a two-line comb filtered color difference signal (RY) _TOP-1H and (BY) _TOP-1H , respectively. ; And 2H com-filtered chrominance signal (RY) _2H-COMB , (BY by using (RY) _V and (RY) _VH and (RY) _VHH , (BY) _V and (BY) _VH and (BY) _VHH , respectively. ₂ ) A method of separating luminance and color signals, characterized in that the process is performed to generate _2H-COMB . The method of claim 1, wherein the correlation detecting step comprises: detecting a correlation between the (RV) _V and the (RY) _VH and the (RY) _VHH to generate a selection signal (X); And detecting a correlation between the (BY) _V and the (BY) _VH and the (BY) _VHH to generate a selection signal (Y). The method of claim 5, wherein the generating of the selection signal X detects a correlation between the (RY) _V and the (RY) _VH and generates a coefficient CO1 _RY to obtain an absolute value A _RY . process; Detecting a correlation between the (RY) _VH and (RY) _VHH to generate a coefficient (CO2 _RY ) to obtain an absolute value (B _RY ); And determining the selection signal (X) with a value greater than A _RY than B _RY . The method of claim 5, wherein the generating of the selection signal X detects a correlation between the (BY) _V and the (BY) _VH and generates a coefficient CO1 _BY to obtain an absolute value A _BY . process; Detecting a correlation between the (BY) _VH and (BY) _VHH and generating a coefficient (CO2 _BY ) to obtain an absolute value (B _BY ); And determining the selection signal (Y) by the value A _BY is greater than B _BY . The method of claim 1, wherein the color-difference signal output process is a process in which the A _RY is greater than B _RY, wherein A _BY that is greater than B _BY selecting said _{(RY) BTM-1H, (} BY) BTM-1H outputs ; A process for the _RY is small, the A _BY output by selecting the _{(RY) TOP-1H, (} BY) TOP-1H smaller than B _{BY RY} than B; And the A _RY is smaller than B _RY, wherein A _BY is greater than B _BY or, and A the _{(RY) 2H-COMB, (} BY) when _RY is greater than B _RY, wherein A _BY is lower than B _{BY 2H -The} luminance / color signal separation method characterized by the process of selecting and outputting _-COMB . The method of claim 1, wherein the color signal outputting process comprises: code conversion for the color difference signals (R-Y) and (B-Y) output in the color difference signal outputting process; And (R-Y), (B-Y),-(R-Y),-(B-Y), and a process for modulating the color signal using a burst signal. A device for separating a luminance signal and a color signal from a composite video signal, wherein a burst signal is obtained from a signal VH obtained by delaying the composite video signal V and the composite video signal V by 1H and a signal VHH delayed by 2H. Demodulation means for demodulating using the color difference signals RY _V and (RY) _VH and (RY) _VHH and (BY) _V and (BY) _VH and (BY) _VHH respectively outputted from the demodulation means. Line comb filtered color difference signal (RY) _BTM-1H and (BY) _BTM-1H , 2 line comb filtered color difference signal (RY) _TOP-1H and (BY) _TOP-1H , 2H comb filtered color difference signal ( RY) color difference signal generating means for generating _2H-COMB and (BY) _2H-COMB ; The correlation between the color difference signal (RY) _V and (RY) _VH and (RY) _VHH and (BY) _V and (BY) | Selection control means for detecting a correlation between _VH and (BY) _VHH and generating a selection signal; The color difference signal ((RY) _BTM-1H , (RY) _TOP-1H , (RY) _2H-COMB ) and the color difference signal ((BY) _BTM-1H , (BY) _TOP-1H , Selecting means for soft-switching (BY) _2H-COMB ) to output an optimum color difference signal; Modulation means for outputting a color signal by modulating the color difference signal output from the selection means using a burst signal; And luminance signal output means for subtracting the color signal outputted by correction delay to the 1H delayed composite video signal (VH) and outputting it as a luminance signal. 11. The apparatus of claim 10, wherein the demodulation means comprises: a bandpass filter for separating color signals by bandpass filtering on the V, VH, and VHH, respectively; A first demodulator for generating a color difference signal (R-Y, B-Y,-(R-Y),-(B-Y)) from the color signal using a clock signal having a burst locked frequency; A second demodulator for generating color difference signals (R-Y, B-Y,-(R-Y),-(B-Y)) from the color signals using the inverted clock signal; And a code converter for latching and encoding the corresponding color difference signals with respect to the color difference signals RY, BY,-(RY) and-(BY), and outputting the color difference signals RY and BY. Luminance / color signal separation device. The apparatus of claim 10, wherein the frequency of the clock signal is 4fsc (fsc: burst signal frequency). 11. The apparatus of claim 10, wherein the color difference signal generating means comprises: a first adder for adding the (RY) _V and (RY) _VH ; A first multiplier for outputting the (RY) _BTM-1H by level converting the output of the first adder to 1/2; A second adder for adding the (BY) _V and (BY) _VH ; A second multiplier for outputting the (BY) _BTM-1H by level converting the output of the second adder by 1/2; A third adder for adding the (RY) _VH and (RY) _VHH ; A third multiplier for level converting the output of the third adder to 1/2 to output the (RY) _TOP-1H ; A fourth adder for adding the (BY) _VH and (BY) _VHH ; A fourth multiplier for outputting the (RY) _TOP-1H by level converting the output of the fourth adder by 1/2; A fifth adder for adding the output of the first multiplier and the output of the third multiplier; A fifth multiplier for outputting the (RY) _2H-COMB by level converting the output of the fifth adder by one half; A sixth adder for adding the output of the second multiplier and the output of the fourth multiplier; And a sixth multiplier for outputting the (BY) _2H-COMB by level-changing the output of the sixth adder by 1/2. 11. The apparatus of claim 10, wherein the selection control means comprises: (RY) correlation detecting means for detecting a correlation between the (RY) _V and (RY) _VH and (RY) _VHH to generate a selection signal (X); And (BY) correlation detecting means for detecting a correlation between (BY) _V and (BY) _VH and (BY) _VHH to generate a selection signal (Y). 15. The apparatus of claim 14, wherein the (RY) correlation detecting means comprises: a first subtractor for subtracting (RY) _VH from the (RY) _V ; The (RY) a second subtractor for subtracting the (RY) _VH to _VH; A first absolute value processor for taking an absolute value of the output CO1 _RY of the first subtractor; A second absolute value processor for taking an absolute value of the output CO2 _RY of the second subtractor; And a comparator for comparing the output A _{RY of} the first absolute value processor and the output B _RY of the second absolute value processor to determine the selection signal X such that A _RY is greater than B _RY . The (BY) correlation detecting means includes: a third subtractor for subtracting (BY) _VH from the (BY) _V ; A fourth subtractor for subtracting (BY) _VHH from the (BY) _VH ; A third absolute value processor for taking an absolute value of the output CO1 _BY of the third subtractor; A fourth absolute value processor for taking an absolute value of the output CO2 _BY of the fourth subtractor; And the third as compared to the absolute value processor output (A _BY) and the output (B _BY) of the fourth absolute value processor of A _BY is composed of a comparator for determining a selection signal (Y) by greater than the B _BY Characterized in the luminance / color signal separation method. 11. The method of claim 10, wherein the selecting means is the A _RY is greater than B _RY, wherein A _BY this case is larger than B _BY and select the _{(RY) BTM-1H, A} RY is smaller than B _RY, wherein A _BY When (RY) _TOP-1H is smaller than B _BY , the A _RY is smaller than B _RY , the A _BY is greater than B _BY , the A _RY is greater than B _RY , and the A _BY is B A first multiplexer for selecting and outputting the (RY) _2H-COMB when smaller than _BY ; And A _RY In this case, if greater than B _RY, wherein A _BY is greater than B _BY selecting the (BY) _BTM-1H, the A _RY is smaller than B _RY, and the A _BY is lower than B _BY (BY) _{TOP If -1H} is selected and the A _RY is less than B _RY , the A _BY is greater than B _BY , or the A _RY is greater than B _RY and the A _BY is less than B _BY , the (BY) _2H-COMB And a second multiplexer for selecting and outputting the luminance / color signal separating apparatus. 11. The method of claim 10, wherein the selecting means is the A _RY is B is greater than _RY selecting the (RY) _BTM-1H, and the A output _RY is selected for the (RY) _TOP-1H smaller than B _RY A third multiplexer; And a fourth multiplexer which selects (BY) _BTM-1H when A _BY is larger than B _BY and selects (BY) _TOP-1H when A _BY is smaller than B _BY. / Color signal separator. 11. The apparatus of claim 10, wherein the modulation means comprises: a code converter for code conversion of the color difference signals (R-Y) and (B-Y) output from the selection means; And a modulator for modulating color signals using (R-Y), (B-Y),-(R-Y),-(B-Y), and burst signals. In the apparatus for separating the luminance signal and the color signal from the composite video signal, the color difference signal RY from the signal VH of delaying the composite video signal V and the composite video signal V by 1H (H is the horizontal scanning period), respectively. Demodulating means for demodulating by using a burst signal to separate _V and (RY, BY) _VH ; Delay means for generating (RY, BY) _VHH by delaying each of the (RY, BY) _VH output from the demodulation means by 1H; The color difference signals (RY) _V and (RY) _VH and (RY) _VHH , (BY) _V, and (BY) _VH and (BY) _VHH are each line-filtered color difference signals (RY) _BTM-1H and (BY) _BTM-1H , 2-line comb filtered color difference signal (RY) _TOP-1H and (BY) _TOP-1H , 2H comb filtered color difference signal (RY) _2H-COMB and (BY) _2H-COMB , respectively The correlation between the (RY) _V and (RY) _VH and (RY) _VHH and the correlation between the (BY) _V and (BY) _VH and (BY) _VHH. The color difference signal ((RY) _BTM-1H , (RY) _TOP-1H , (RY) _2H-COMB ) and the color difference signal ((BY) _BTM-1H , (BY) _TOP-1H , (BY) _2H- Selecting means for soft-switching each _COMB ) to output an optimum color difference signal; Modulation means for outputting a color signal by modulating the color difference signal output from the selection means using a burst signal; And luminance signal output means for subtracting the color signal outputted by correction delay to the 1H delayed composite video signal (VH) and outputting it as a luminance signal.