KR0141127B1 - Apparatus for separating chroma signal - Google Patents

Abstract

Disclosed is a color signal separating apparatus for separating color signals by a vertical correlator or a horizontal correlator depending on whether or not there is a vertical correlation between horizontal scan lines.

The vertical correlation between the vertical correlator separating color signals by the vertical correlation between the sequential horizontal scan lines and the horizontal correlator separating the color signals by the horizontal correlation between the front and back color signals on a horizontal scan line and the vertical correlation between the horizontal corrugated lines and the sequential horizontal scan lines And a vertical correlator for selecting the vertical correlator or the horizontal correlator.

Description

Color signal separator

1 is a view showing an example of the color signal separation device according to the present invention.

2 is a view showing a detailed configuration of the vertical correlator shown in FIG.

3 is a diagram showing an exemplary image.

4 is a view showing a horizontal scan line input to the color signal separation device of FIG.

5 is a view showing angular waveforms of the vertical correlator of FIG.

6 is a view showing a detailed configuration of the horizontal correlator shown in FIG.

7 is a diagram showing the detailed configuration of the vertical correlator discriminator shown in FIG.

8 is a view showing another embodiment of the color signal separation device according to the present invention.

* Explanation of symbols for the main parts of the drawings

1,2: delay 3: inverter

4,5,6: bandpass filter 15: vertical correlator

20: horizontal correlator 30: vertical correlator discriminator

42: correction delay delay 43: subtractor

60: switch

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a color signal processing apparatus in a color image signal processing apparatus. In particular, the present invention relates to a color signal separation apparatus that separates color signals by a vertical correlator or a horizontal correlator based on vertical correlation between horizontal scan lines.

The current color television system uses a composite video signal in which the color signal balanced by the chroma signal is frequency superimposed on the luminance signal. For this reason, a color signal separation device is required on the receiving side. Early color signal separation devices used low pass filters or band pass filters. However, since the low pass filter and the band pass filter cannot completely separate the luminance signal and the color signal, problems such as cross color (color signal component generated by the luminance signal component of the same frequency as the color carrier) or color smear occur. Since then, a two-line comb filter (comb filter) has been developed, which greatly improves color signal separation performance. The two-line type comb filter uses the same phase of the luminance signal and inverts the phase of the color signal in two adjacent horizontal scan lines, delaying one horizontal scan line for one horizontal scanning period, and subtracting it from the next horizontal scan line. A color signal from which the luminance signal is canceled is obtained and used again to separate the luminance signal. However, since the two-line type comb filter separates color and luminance signals by adding or subtracting color signals of two horizontal scan lines, color blur in the vertical direction cannot be avoided. In order to solve this problem, a method of separating color signals and luminance signals by adding or subtracting color signals of three horizontal scan lines, that is, a three-line comb filter, has been proposed (US Patent 4,930,005). It is determined by the correlation between the color signals of the horizontal scan line and the color signals of the horizontal scan line adjacent to the front and rear thereof. Therefore, there is an effect that the resolution in the vertical direction is increased and the DOT interference in the horizontal direction is lightened. In such a three-line comb filter, a method of separating color signals by vertical correlation has been adopted, but it is preferable to perform color signal separation using horizontal scan lines in the horizontal scan lines. In other words, the separation of the color signals by the vertical correlator in the vertical correlation part and the separation of the color signals by the horizontal correlator in the part without vertical correlation may be more efficient.

Japanese Patent Laid-Open No. 1-93284 ('89 .4.12) discloses a luminance / color signal separation device having a horizontal filter, a vertical filter, and a correlation discriminator for selecting a horizontal filter or a vertical filter.

Since the apparatus of Japanese Patent Laid-Open No. Hei 1-93284 has four targets for determining the correlation discriminator, such as horizontal, vertical, leftward inclination, and rightward inclination, there is a high probability of discrimination at each boundary of the correlation discriminator. In addition, the removal of the cross color in the vertical uncorrelated portion (the portion where there is no correlation between adjacent horizontal scanning lines) is insufficient, the removal of the cross collar in the high latitude slope portion and the cross collar removal in the high latitude slope portion is poor. There is a problem that is difficult.

Accordingly, it is an object of the present invention to provide a color signal separation apparatus that performs efficient color signal separation by reducing the correlation target of the correlation correlator in a device using a vertical correlator or a horizontal correlator due to the vertical correlation of an image signal.

Another object of the present invention is to provide a horizontal correlator, a vertical correlator, and a vertical correlation device suitable for the color signal separation device.

The color signal separation apparatus of the present invention for achieving the above object is a three-line vertical correlator, a three-line horizontal correlator, and a vertical correlator or horizontal to effectively remove the cross color in the vertical uncorrelated portion and the high latitude oblique line portion And a vertical correlation detector for generating a selection signal for selecting one of the correlators.

The vertical correlator may include: a first low voltage detector configured to introduce a video signal and a second video signal obtained by delaying and reversing the video signal by a first predetermined period, and to select and output a signal having a low voltage level among them;

A second low voltage detector for introducing the second video signal and a third video signal obtained by delaying the video signal by a second predetermined period, and selecting and outputting a signal having a low voltage level among them;

A first high voltage detector configured to input the video signal and the second video signal, and select and output a signal having a high voltage level among them;

A second high voltage detector configured to input the second image signal and the third image signal, and select and output a signal having a high voltage level among them;

A first zero level signal generator configured to convert a color signal modulated with a zero level chroma signal;

A third high voltage detector configured to input an output of the first low voltage detector, an output of the second low voltage detector, and an output of the first zero level signal generator, and select and output a signal having a high voltage level among them;

A third low voltage detector configured to input an output of the first high voltage detector, an output of the second high voltage detector, and an output of the first zero level signal generator, and select and output a signal having a low voltage level among them;

And

It is preferable to include the 1st adder which flows in the output of the said 3rd high voltage detector, and the output of the said 3rd low voltage detector, adds them, and outputs them.

The horizontal correlator delays the image signal, the fourth image signal obtained by delaying the image signal by 1/2 cycle (1/2 T _SC ) of the color subcarrier and inverts the phase, and delays the image signal by the period of the color carrier. A fourth low voltage detector which inputs the obtained fifth image signal and selects and outputs a signal having a low voltage level among them;

A fourth high voltage detector configured to input the video signal, the fourth video signal, and the fifth video signal, and select and output a signal having a high voltage level among them;

A fifth high voltage detector configured to input an output of the fourth low voltage detector and an output of the second zero level signal generator, and select and output a signal having a high voltage level among them;

A fifth low voltage detector configured to input an output of the fourth high voltage detector and an output of the second zero level signal generator, and select and output a signal having a low voltage level among them; And

It is preferable to include the 2nd adder which flows in the output of the said 5th high voltage detector, and the output of the said 5th low voltage detector, adds them, and outputs them.

And the vertical correlation discriminator

A first absolute value circuit for introducing the video signal and calculating an absolute value thereof;

A second absolute value circuit for introducing a second image signal obtained by delaying the video signal by a first predetermined period and inverting the phase and calculating an absolute value thereof;

A third absolute value circuit for introducing a third video signal obtained by delaying the video signal by a second predetermined period and calculating an absolute value thereof;

A first subtractor for subtracting the output of the first absolute value circuit and the output of the second absolute value circuit;

A second subtractor for subtracting the output of the second absolute value circuit and the output of the third absolute value circuit;

A fourth absolute value circuit for introducing an output of the first subtractor and calculating an absolute value thereof;

A fifth absolute value circuit for introducing an output of the second subtractor and calculating an absolute value thereof;

A threshold generator for generating a predetermined threshold;

A first comparator for comparing the output of the fourth absolute value circuit with a threshold generated by the threshold generator to generate a first discrimination signal indicating whether the output of the fourth absolute value circuit is greater than a threshold;

A second comparator for comparing the output of the fifth absolute value circuit with a threshold generated by the threshold generator to generate a second discrimination signal indicating whether the output of the fifth absolute value circuit is greater than a threshold; And

It is preferable to include a logical sum operator for performing a logical sum operation on the first discrimination signal output from the first comparator and the second discrimination signal output from the second comparator. Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing the color signal separation apparatus of the present invention showing an example in the case of applying to the NTSC system. The color signal separation device of the present invention shown in FIG. 1 includes delayers 1, 2, inverters 3, band pass filters 4, 5, 6, vertical correlators 15, horizontal correlators 20, vertical A correlation discriminator 30 and a switch 60 are provided.

The first, second, and third band pass filters 4, 5, and 6 have a pass frequency (3.58 MHz in the case of NTSC) as the pass frequency of the color subcarrier.

The input video signal a is supplied to the first delay unit 1 and the first band pass filter 4. The delayed signal b output from the first delay unit 1 is supplied to the first inverter 3 and the second delay unit 2. The signal d inverted from the first inverter 3 is supplied to the second band pass filter 5. The delayed signal c from the second delay unit 2 is supplied to the third band pass filter 6.

FIG. 2 is a diagram showing an example of a vertical correlator in FIG.

The vertical correlator shown in FIG. 2 is a first second and third low voltage detection circuit (hereinafter referred to as a MIN circuit) (7, 8, 12), a first second and third high voltage detection circuit. (9, 10, 11), a first adder 13, and a first zero-level signal generator 14. The high voltage detection circuits 7, 8, and 12 detect the highest voltage between the input signals and output the voltage. The low voltage detection circuits 9, 10 and 11 detect the lowest voltage between the input signals and output the voltage.

The first zero level signal generator 14 generates a color carrier signal modulated by a zero level color signal. In the current color television system, color carriers modulated with color signals are transmitted superimposed on luminance signals. The receiving side separates the color carriers overlaid on the luminance signal and modulated by the transmitted color signal through a bandpass filter having a bandpass frequency corresponding to the frequency of the color carriers. The color carriers modulated by the color signal superimposed on the luminance signal change their center values according to the potential change of the luminance signal, but the color carriers modulated by the color signal through the bandpass filter have a sinusoidal wave oscillating up and down with a constant potential as the center value. do. In other words, when a color signal is present, it becomes a sine wave having a certain phase and wave height, and when the color signal does not exist, the constant potential is maintained. Normally, this constant potential is the earth voltage. Accordingly, the first zero level signal generator 14 preferably has a constant voltage power supply, but may be of the type that is grounded directly or through a resistor or the like.

The bandpassed signal e in the first bandpass filter 4 is supplied to the first MIN circuit 7 and the first MAX circuit 9. The bandpassed signal f in the second bandpass filter 5 is supplied to the first second MIN circuits 7 and 8 and the first second MAX circuits 9 and 10. The bandpassed signal g in the third bandpass filter 6 is applied to the second MAX 10 circuit.

In the first MIN circuit 7, a first low voltage signal h between signals e and f is generated, and the first low voltage signal f is supplied to the third MAX circuit 11.

In the second MIN circuit 8, a second low voltage signal i between the signals f and g is generated and this second low voltage signal g is supplied to the third MAX circuit 11.

In the first MAX circuit 9, a first high voltage signal j is generated between the signals e and f, and the first high voltage signal j is supplied to the second MIN circuit 12.

In the second MAX circuit 10, a second high voltage signal k is generated between the signals f and g, and the second high voltage signal k is supplied to the second MIN circuit 12. Meanwhile, the zero level signal 1 of the first zero level signal generator 14 is supplied to the third MAX circuit 11 and the third MIN circuit 12.

In the third MAX circuit 11, a third high voltage signal m between the first low voltage signal h, the second low voltage signal i, and the zero level signal 1 is generated, and the third high voltage signal m is supplied to the first adder 13. . In the third MIN circuit 12, the first high voltage signal j and the second high voltage signal k generate a third low voltage signal n between the zero level signals 1 and the third low voltage signal n is supplied to the first adder 13. . In the first adder 13, a signal o to which the third high voltage signal m and the third low voltage signal n are added is generated, and the added signal o is output as an output of a three-line comb filter, that is, as a separate color signal.

The operation of the vertical correlator 15 shown in FIG. 2 will be described in detail with reference to FIGS. 3A-3B, 4A-4D and 5A-5D.

First, the color signal separation operation in the vertical decorrelating portion will be described. It is assumed that a carrier color signal having an original image as shown in FIG. 3A is applied to the color signal separation device of FIG. The image consists of a colorless part (A) at the top, a colorated part (C) at the center, and an uncolored part (E) at the bottom. The symbol B represents the first horizontal scan line of the center colored part (C), and the symbol D represents the first horizontal scan line of the uncolored part E at the bottom.

When the signal corresponding to the portion B is output from the first delay unit 1, the horizontal scan line signals p, q and r sequentially on the screen are displayed as shown in FIG. 4A. In this case, in the color signal separation apparatus of FIG. 1, the signals of the respective parts d, e, f, g, h, i, j, k, l, m, n and the signal o from which the cross color is removed are shown in FIG. 5A.

When the signal corresponding to the portion D is output from the first delay unit 1, the sequential horizontal scan line signals p, q and r on the screen are displayed as shown in FIG. 4B. In this case, the signals d, e, f, g, h, i, j, k, l, m, n and o in the color signal separator of FIG. 1 are shown in FIG. 5B. It can be seen that no color signal is output in the signal o.

When the sequential signals p, q and r have the same color, all signals e, f, g, h, i, j, k, l, m, n and o with the same color are shown in FIG. Is shown on. In addition, if all signals do not have a color, a signal o that does not have a color is also obtained.

An operation of removing the luminance signal of the component corresponding to the frequency of the color subcarrier will be described. Since there is no phase difference of the luminance signal between adjacent horizontal scan lines, the horizontal scan line signals p, q, and r sequentially on the screen are displayed as shown in FIG. 4D. In this case, the signals d, e, f, g, h, i, j, k, l, m, n and the signal o from which the cross color is removed in the color signal separator of FIG. 1 are shown in FIG. 5D.

As described above, the vertical correlator can obtain a color signal having good vertical resolution and reduced horizontal DOT interference by using vertical correlation between three horizontal scan lines.

6 is a view showing an example of the horizontal correlator of FIG. The horizontal correlator shown in FIG. 6 is a retarder 21, 22, an inverter 23, fourth and fifth high voltage detection circuits 25 and 26, and fourth and fifth low voltage detectors 24 and 27. And a second adder 28 and a second zero level signal generator 29. The fourth and fifth delayers 21 and 22 have a delay characteristic corresponding to one-half period of the color carrier.

The operation of the horizontal correlator will be described with the configuration of FIG. Carrier color signals from the band pass filters 4, 5, and 6 having a frequency characteristic in which the frequency of the color subcarrier is set to a pass frequency (3.58 MHz in the case of NTSC) are obtained by the third delayer 21, the fourth MIN circuit 24, Then, it is supplied to the fourth MAX circuit 26. The delayed signal p output from the third delay 21 is supplied to the inverter 23 and the fourth delay 22. The inverted signal q from the inverter 23 is supplied to the fourth MIN circuit 24 and the fourth MAX circuit 26. The delayed signal r output from the fifth delay unit 22 is supplied to the fourth MIN circuit 24 and the fourth MAX circuit 26.

In the 4MIN circuit 24, the carrier color signal f through the first delay unit 1 and the inverter 3 in FIG. 1, the inverted signal q, and the signal r delayed by the fifth delay unit 22 are shown. The fourth low voltage signal s is obtained, and this fourth low voltage signal s is supplied to the fifth MAX circuit 25. In the 4MAX circuit 26, the carrier color signal f through the first delay unit 1 and the inverter 3 in FIG. 1, the inverted signal q and the signal r delayed by the fifth delay unit 22 The fourth high voltage signal t is obtained, and this fourth high voltage signal t is supplied to the fifth MIN circuit 27. The zero level signal u from the second zero level signal generator 29 is supplied to the fifth MAX 25 and the fifth MIN circuit 27. In the fifth MAX circuit 25, the fifth high voltage signal v between the fourth low voltage signal s and the zero level signal u is obtained, and the fifth high voltage signal v is supplied to the second adder 28. In the fifth MIN circuit, the fifth high voltage signal w between the fourth low voltage signal t and the zero level signal u is obtained, and the fifth high voltage signal w is supplied to the second adder 28. In the fifth MIN circuit 27, the fifth low voltage signal w between the fourth high voltage signal t and the zero level signal u is obtained, and the fifth low voltage signal w is supplied to the second adder 28. In the second adder 28, a signal x obtained by adding the fifth high voltage signal v and the fifth low voltage signal w is obtained, and the added signal x is provided as an output signal of the horizontal correlator 20.

The operation of the horizontal correlator in the video signal having a high luminance gradient line will be described with reference to FIGS. 3B, 4D, and 5E. It is assumed that a signal having the original image of FIG. 3B is provided as an input image signal of FIG. The image of FIG. 3B has a high luminance line in the diagonal direction on the screen. It is assumed that the horizontal distance between adjacent high-level inclination lines and the adjacent horizontal scanning lines is 1/2 of the wavelength of the carrier color signal. The symbol F is shown to represent the scanning line at any position on the screen. When a signal corresponding to the portion F of FIG. 3B is output from the fourth delay unit 21, the horizontal scan line signals a ', b', and c 'on the screen are displayed as shown in FIG. 4D. In this case, the respective signals f, p, q, r, s, t, u, v, w, and x are shown in FIG. 5E.

As described above, the horizontal correlator delays the horizontal scanning component by one and one wavelengths of the color carrier and enables color signal separation by horizontal correlation between the delayed signals.

Therefore, it is preferable to separate the color signal by the vertical correlator or the horizontal correlator according to the state of the correlation of the video signal.

7 is a diagram showing an example of the vertical correlation discriminator of FIG. The vertical correlation coefficient shown in FIG. 7 includes the absolute value circuits 31, 32, 33, 36, 37, the subtractors 34, 35, the comparators 38, 39, the threshold generator 40, and the logic operator ( 41).

The absolute value circuit generates an absolute value of the signal input thereto and provides it as an output signal. Threshold generator 40 provides a threshold K for determination of vertical correlation.

In determining the vertical correlation between sequential and adjacent scanning lines, the vertical correlation coefficient discriminator of the present invention first determines the vertical correlation between the first scan line and the second scan line, and then the vertical between the second scan line and the third scan line. By judging the correlation and performing a logical operation of the two judgment results, when either of the two cases has vertical correlation, color signal separation by the vertical correlator is performed. Furthermore, in determining the vertical correlation between the scan lines, it is possible to set its sensitivity or threshold.

The operation of the vertical correlation detector according to the configuration of FIG. 7 will be described in detail. The carrier color signal e from the band pass filters 4, 5, and 6 having a frequency characteristic that sets the frequency of the color subcarrier as the pass frequency (3.58 MHz in the case of NTSC) is supplied to the first absolute value circuit 31. The inverted signal f from the inverter 3 is supplied to the second absolute value circuit 32. The delayed signal g from the second delay unit 2 is supplied to the third absolute value circuit 33. The first absolute value signal 31a from the first absolute value circuit 31 is supplied to the means to be subtracted from the third subtractor 34. The second absolute value signal 32a from the second absolute value circuit 32 is supplied to the subtracted means of the fourth subtractor 35 while being supplied to the subtracted means of the third subtractor. The third absolute value signal 33a from the third absolute value circuit 33 is supplied to the subtractor of the fourth subtractor 34. In the third subtractor 34, a first subtracted signal 34a is generated between the first absolute value signal 31a and the second absolute value signal 32b, and the first subtracted signal 34a is supplied to the fourth absolute value circuit 36. . In the fourth subtractor 35, a second subtracted signal 35a is generated between the second absolute value signal 32a and the third absolute value signal 33a, and the second subtracted signal 35a is supplied to the fifth absolute value circuit.

The fourth absolute value signal 36a from the fourth absolute value circuit 36 is supplied to the first comparator 38. The fourth absolute value signal 37a from the fifth absolute value circuit 37 is supplied to the second comparator 39. The threshold value k from the threshold generator 40 is supplied to the first comparator 38 and the second comparator 39.

In the first comparator 38, a first comparison decision signal 38a between the fourth absolute value signal 36a and the threshold value k is generated and the first comparison decision signal 38a is supplied to the logic comparator 41. In the second comparator 39, a second comparison determination signal 39a between the fifth absolute value signal 37a and the threshold value K is generated, and the second comparison determination signal 39a is supplied to the logic comparator 41.

In the logical sum calculator 41, a logic sum signal y of the first comparison decision signal 38a and the second comparison decision signal 39a is generated, and the logic sum signal y is provided as an output signal of the vertical correlation determiner.

The switch 60 is switched by the output signal from the vertical correlation detector 30 to select and output the output signal o of the vertical correlator 15 or the output signal x of the horizontal correlator 20.

As described above, the color signal separation apparatus of the present invention achieves excellent color signal separation by allowing the conventional color signal separation apparatus to separate the color signals only by the vertical correlation between adjacent scan lines, but also by the horizontal correlation between the scan lines. .

In addition, color signal separation efficiency by the vertical correlator or color signal separation by the horizontal correlator is improved by the degree of vertical correlation.

Those who are familiar with image signal processing will be well aware of separating luminance signals using the separated color signals in the color signal separation apparatus of the present invention. Such a luminance signal separation device typically includes a delay and a subtractor for correcting a transmission delay error with a color signal processed through the color signal separation device.

8 is another embodiment of the color signal separation apparatus of the present invention. The color signal separator shown in FIG. 8 further includes a correction delay unit 42 and a subtractor 43 in addition to the color signal separator of FIG. The delayed signal b from the first delayer 1 is corrected to correct the phase with the color signal z separated through the correction delayer 42. The correction delayed signal from the delay unit 42 is input to the subtracted means of the subtractor 43. The separated means z of the subtractor 43 is supplied with the separated color signal z. In the subtractor 43, a subtracted signal between the correction delayed signal and the separated color signal z is generated, and the subtracted signal is provided as a separate luminance signal.

The apparatuses of the present invention can be commonly applied to NTSC and PAL. For example, the delayers shown in FIG. 1 delay by one horizontal syringe stem 1H. This is because in the NTSC system, the phase of the color carrier is opposite between adjacent horizontal scan lines. Since the phase of the color carrier is 90 ° between adjacent horizontal scan lines in the PAL method, the delay characteristics of the retarders may be changed to 2H to be applied to the PAL method. In addition, the pass frequency of the band pass filter is also 4.3 MHz in the PAL method.

Accordingly, it is apparent that the objects and spirit of the present invention should not be limited to the embodiments shown but should be determined by the appended claims.

Claims (7)

Vertical correlator 15 for separating the color signal by the vertical correlator of the video signal, Horizontal correlator 20 for separating the color signal by the horizontal correlation of the video signal, Vertical for judging whether the vertical correlation of the video signal is greater than a predetermined size Color signal separation having a correlation discriminator 30 and a switch 60 for selectively outputting the output of the vertical correlator 15 or the horizontal correlator 20 according to the determination result of the vertical correlation correlator 30. In the apparatus, the vertical correlator 15 introduces a second video signal obtained by delaying and inverting the video signal and the video signal by a first predetermined period, and selecting and outputting a signal having a low voltage level among them. 1 low voltage detector; A second low voltage detector for introducing the second video signal and a third video signal obtained by delaying the video signal by a second predetermined period, and selecting and outputting a signal having a low voltage level among them; A first high voltage detector configured to input the video signal and the second video signal, and select and output a signal having a high voltage level among them; A second high voltage detector configured to input the second image signal and the third image signal, and select and output a signal having a high voltage level among them; A first zero level signal generator configured to convert a color signal modulated with a zero level chroma signal; A third high voltage detector configured to input an output of the first low voltage detector, an output of the second low voltage detector, and an output of the first zero level signal generator, and select and output a signal having a high voltage level among them; A third low voltage detector configured to input an output of the first high voltage detector, an output of the second high voltage detector, and an output of the first zero level signal generator, and select and output a signal having a low voltage level among them; And a first adder for inputting the output of the third high voltage detector and the output of the third low voltage detector and adding them to the output. 4. The horizontal correlator of claim 1, wherein the horizontal correlator delays the video signal, the video signal by one-half cycle of the color carrier, and inverts the fourth signal, and the video signal by the period of the color carrier. A fourth low voltage detector which inputs the obtained fifth image signal and selects and outputs a signal having a low voltage level among them; A fourth high voltage detector configured to input the video signal, the fourth video signal, and the fifth video signal, and select and output a signal having a high voltage level among them; A fifth high voltage detector configured to input an output of the fourth low voltage detector and an output of the second zero level signal generator, and select and output a signal having a high voltage level among them; A fifth low voltage detector configured to input an output of the fourth high voltage detector and an output of the second zero level signal generator, and select and output a signal having a low voltage level among them; And a second adder for inputting the output of the fifth high voltage detector and the output of the fifth low voltage detector and adding them to the output. 2. The apparatus of claim 1, wherein the vertical correlation coefficient discriminator comprises: a first absolute value circuit for introducing the image signal and calculating an absolute value thereof; A second absolute value circuit for introducing a second video signal obtained by delaying the video signal by a first predetermined period and inverting a phase and calculating an absolute value thereof; a third video signal obtained by delaying the video signal by a second predetermined period; A third absolute value circuit which flows in and calculates its absolute value; A first subtractor for subtracting the output of the first absolute value circuit and the output of the second absolute value circuit; A second subtractor which subtracts the output of the second absolute value circuit and the output of the third absolute value circuit; A fourth absolute value circuit for introducing an output of the first subtractor and calculating an absolute value thereof; A fifth absolute value circuit for introducing an output of the second subtractor and calculating an absolute value thereof; A threshold generator for generating a predetermined threshold; A first comparator for comparing the output of the fourth absolute value circuit with a threshold generated by the threshold generator to generate a first discrimination signal indicating whether the output of the fourth absolute value circuit is greater than a threshold; A second comparator for comparing a output of the fifth absolute value circuit with a threshold generated by the threshold generator to generate a second discrimination signal indicating whether the output of the fifth absolute value circuit is greater than a threshold; And a logical sum calculator configured to perform a logical sum operation on the first discrimination signal output from the first comparator and the second discrimination signal output from the second comparator. 3. The apparatus of claim 2, wherein the vertical correlation coefficient discriminator comprises: a first absolute value circuit for introducing the image signal and calculating an absolute value thereof; A second absolute value circuit for introducing the second image signal and calculating an absolute value thereof; A third absolute value circuit for introducing the third image signal and calculating an absolute value thereof; A first subtractor for subtracting the output of the first absolute value circuit and the output of the second absolute value circuit; A second subtractor which subtracts the output of the second absolute value circuit and the output of the third absolute value circuit; A fourth absolute value circuit for introducing an output of the first subtractor and calculating an absolute value thereof; A fifth absolute value circuit for introducing an output of the second subtractor and calculating an absolute value thereof; A threshold generator for generating a predetermined threshold; A first comparator for comparing the output of the fourth absolute value circuit with a threshold generated by the threshold generator to generate a first discrimination signal indicating whether the output of the fourth absolute value circuit is greater than a threshold; A second comparator for comparing a output of the fifth absolute value circuit with a threshold generated by the threshold generator to generate a second discrimination signal indicating whether the output of the fifth absolute value circuit is greater than a threshold; And a logical sum calculator configured to perform a logical sum operation on the first discrimination signal output from the first comparator and the second discrimination signal output from the second comparator. 4. The display device of claim 3, wherein the horizontal correlator comprises: a fourth low voltage detector configured to input the video signal, the fourth video signal, and the fifth video signal, and select and output a signal having a low voltage level among them; A fourth high voltage detector configured to input the video signal, the fourth video signal, and the fifth video signal, and select and output a signal having a high voltage level among them; A fifth high voltage detector configured to input an output of the fourth low voltage detector and an output of the second zero level signal generator, and select and output a signal having a high voltage level among them; A fifth low voltage detector configured to input an output of the fourth high voltage detector and an output of the second zero level signal generator, and select and output a signal having a low voltage level among them; And a second adder for inputting the output of the fifth high voltage detector and the output of the fifth low voltage detector and adding them to the output. In a horizontal correlator for separating color signals by horizontal correlation of a video signal, a fourth video signal obtained by delaying and phase reversing the video signal by a half cycle of a color carrier, and delaying the video signal by a cycle of a color carrier A fourth low voltage detector for inputting a fifth image signal obtained by injecting the same, and selecting and outputting a signal having a low voltage level among them; A fourth high voltage detector configured to input the video signal, the fourth video signal, and the fifth video signal, and select and output a signal having a high voltage level among them; A fifth high voltage detector configured to input an output of the fourth low voltage detector and an output of the second zero level signal generator, and select and output a signal having a high voltage level among them; A fifth low voltage detector configured to input an output of the fourth high voltage detector and an output of the second zero level signal generator, and select and output a signal having a low voltage level among them; And a second correlator including an output of the fifth high voltage detector and an output of the fifth low voltage detector and adding and outputting them. A vertical correlation checker for determining vertical correlation of a video signal, comprising: a first absolute value circuit for introducing the video signal and calculating an absolute value thereof; A second absolute value circuit for introducing a second video signal obtained by delaying the video signal by a first predetermined period and inverting a phase and calculating an absolute value thereof; A third absolute value circuit for introducing a third video signal obtained by delaying the video signal by a second predetermined period and calculating an absolute value thereof; A first subtractor for subtracting the output of the first absolute value circuit and the output of the second absolute value circuit; A second subtractor which subtracts the output of the second absolute value circuit and the output of the third absolute value circuit; A fourth absolute value circuit for introducing an output of the first subtractor and calculating an absolute value thereof; A fifth absolute value circuit for introducing an output of the second subtractor and calculating an absolute value thereof; A threshold generator for generating a predetermined threshold; A first comparator for comparing the output of the fourth absolute value circuit with a threshold generated by the threshold generator to generate a first discrimination signal indicating whether the output of the fourth absolute value circuit is greater than a threshold; A second comparator for comparing a output of the fifth absolute value circuit with a threshold generated by the threshold generator to generate a second discrimination signal indicating whether the output of the fifth absolute value circuit is greater than a threshold; And a logical sum operator configured to perform an OR operation on the first discrimination signal output from the first comparator and the second discrimination signal output from the second comparator.