JPH0344717B2 - - Google Patents

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal separation device, and more particularly to a device used in an NTSC television receiver to separate and extract a color signal and a luminance signal from a color video signal. 2. Description of the Related Art A so-called comb filter is used to separate a color signal and a luminance signal from a color video signal. In this case, as schematically shown in Fig. 14, a comb-shaped characteristic is created in which the luminance signal (A in the figure) and the color signal (B in the figure) are equally divided for each horizontal frequency in the frequency band of the color signal. This is the signal separation method that is the mainstream in television receivers of the current popular type and above. On the other hand, the color subcarrier (frequency _S c = 3.579545MHz) in the color video signal of the NTSC system is the
1) The phase is reversed between each line, which is a characteristic of the NTSC system. Γ in the diagram
The marks and ● marks indicate the sampling frequency _S and the color subcarrier frequency.
The sample points are shown when _S is set to 4 times c. Below, we will consider sample points marked with ● that correspond between lines. FIG. 16 shows a block system diagram of an example of a conventional signal separation device. For example, the color signal a for 5 lines (A in Fig. 17, the horizontal axis in the figure is the vertical direction of the screen) that enters the terminal 1 is delayed by 1H in the 1H delay circuit 2 and becomes the signal b (B in the figure). The adder 3 outputs the signals a,
b is added and its level is halved to obtain signal c (C in the same figure).Meanwhile, signal b is subtracted from signal a in subtracter 4 and its level is halved.
The signal d (D in the same figure) is obtained. The signal d is taken out as a color signal d through a band filter 5 having a center frequency _S c and passing a band signal of ±500 kHz, and is taken out from an output terminal 6. The signal c is corrected by the delay time generated by the bandpass filter 5 in the delay circuit 7 and is supplied to the adder 8.
On the other hand, the signal d is corrected by the delay time in the delay circuit 9, the output of the bandpass filter 5 is subtracted in the subtracter 10, and the output of the subtracter 10 and the output of the delay circuit 7 are added in the adder 8. and is taken out from the output terminal 11 as a distortion component e'. On the other hand, for example, the luminance signal a for 5 lines (A in FIG. 18, modulation frequency _S c) inputted to the terminal 1 is converted into the signal b (B in the same figure) by the 1H delay circuit 2, and the adder 3
At , signals a and b are added and their level is halved to form signal c (C in the same figure), while subtracter 4
The signal b is subtracted from the signal a and its level is halved to form a signal d' (D in the figure), which is taken out from the output terminal 6 as a distortion component d' via a bandpass filter 5. The signal c is time-corrected in the delay circuit 7, and the signal
d' is time-corrected in the delay circuit 9, the output of the bandpass filter 5 is subtracted in the subtracter 10, and the output of the subtracter 10 and the output of the delay circuit 7 are added in the adder 8, and the luminance signal e is (E in the same figure) output terminal 11
taken out from Problems to be Solved by the Invention In the above-mentioned conventional device, for color signals, as is _clear from FIG.
Since d ₂ is 1/2 of the level of the input color signal, distortion occurs, and as is clear from E in the same figure, luminance signal components e ₁ and e ₂ that should not exist occur at the edge portions, and furthermore, the output The number of lines of the color signal increases by one line compared to that of the input color signal. On the _other hand, for the luminance signal, as _is clear from FIG. As shown, color signal components d ₃ and d ₄ which should not exist in the first place occur in the edge portion, and furthermore, the number of lines of the output luminance signal increases by one line compared to that of the input luminance signal. As described above, the conventional apparatus has a problem in that interference such as cross color occurs at the edge portion in the vertical direction, resulting in a significant deterioration in image quality. SUMMARY OF THE INVENTION It is an object of the present invention to provide a signal separation device that can eliminate interference such as cross color particularly at vertical edge portions and improve image quality. Means to solve the problem In Fig. 1, band filter 12, 1H delay circuit 1
3, 14, 16, 261H delay circuit 15, subtracter 1
7 to 19 are sample points with color signals and luminance signals.
x ₁ , the sampling point one horizontal scanning period before the sampling point x ₁ is x ₀ ,
The sampling point after 1 horizontal scanning period of sampling point x ₁ is x ₂ , the sampling point 262 horizontal scanning periods before sampling point x ₁ is y ₁ , the sampling point
When the sample point 263 horizontal scanning periods before x ₁ is y ₀ , the difference signal D ₀ = (x ₁ − x ₀ )/2, D ₁ = (y ₁ − y ₀ )/2, D ₂ = ( x ₁ −x ₂ )/2, the color signal determination circuit 20 calculates {D ₀ +D ₂ −β ₁ (D ₀ −D ₂ )} under the conditions of 1<β ₁ <3, β ₂ ≧2. {D ₀ +D ₂ +β ₁ (D ₀ −D ₂ )}＞0, (β ₂ D ₁ −D ₀ )(β ₂ D ₁ +D ₀ )≧0, (β ₂ D ₁ −D ₂ )(β ₂ means for generating a color signal determination signal by detecting that D ₁ +D ₂ )≧0 is established at the same time;
The color signal setting circuit 21, the switch circuit 38, and the band filter 51 output the color signal determination signal generation time difference signal D ₀ ,
Means for obtaining output color signals from D ₁ and D ₂ , 1H delay circuit 52, delay circuit 53, and subtracter 54, subtract the output color signal from the input color video signal delayed by one horizontal scanning period to obtain the output luminance signal. It is a means to obtain Function Subtractor 1 subtracts the input color video signal from the signals obtained from band filter 12 and delay circuits 13 to 16, respectively.
7, 18, and 19, the difference signals D ₂ , D ₀ , D ₁ respectively
The color signal determination circuit 20 determines the presence of a color signal, and the color signal setting circuit 21 and switch circuit 38
An output color signal is obtained by using the 1H delay circuit 52, a delay circuit 53, and a subtracter 54 to obtain an output luminance signal. Embodiment First, let us consider the properties of a color video signal related to the present invention. FIG. 4 shows a diagram showing the scanning state of the screen in the NTSC system. The solid line is the scanning line of the current field, and the broken line is the scanning line of the previous field, and these are in an interleaving relationship with each other. The upper part of the figure is the top of the screen, the vertical direction is the vertical direction in which scanning goes from top to bottom, and the horizontal direction is the horizontal direction in which scanning goes from left to right. Now, let the sampling points of the (n-1)th line, nth line, and (n+1)th line in the current field in the vertical direction of the screen be x ₀ , x ₁ , and x ₂ , respectively, and the sample points in the previous field located in the middle thereof. No. (n-263)
The sample points of the line and the (n-262)th line are respectively y ₀ ,
Let y be ₁ . Here, if color information exists on the screen as a still image, each sample point x ₀ , x ₁ ,
As shown in FIGS. 5A to 5E, x ₂ , y ₀ , and y ₁ are located at the positions indicated by black circles in the color signal waveform of each line represented by a sine wave having a frequency of _Sc . Note that the ● mark and the Γ mark are the positions of sampling points when the color signal is sampled at a frequency of 4 _S c. FIG. 6 shows the phase relationship of each field and each line of the color signal in coordinates consisting of a vertical axis and a time axis. , indicates that the phases are inverted, and the sample points x ₀ , x ₁ , x ₂ , y ₀ , y ₁ in FIGS. 4 and 5 match those in FIG. 6. The present invention uses these five sample points to discriminate and separate the color signal and the luminance signal. FIG. 7A shows the sample points x ₀ , x ₁ , x ₂ , y ₀ ,
A diagram showing the level of y ₁ seen from left to right on the time axis. Figure B is the next sample point x ₀ ' in Figure 5,
This figure shows the levels of x ₁ ′, x ₂ ′, y ₀ ′, and y ₁ ′ when viewed from left to right on the time axis, and the polarity of each level in A and B in the figure is reversed. There is. Now, Figure 7A
Consider the following difference signals D ₀ , D ₁ , and D ₂ . D ₀ = (x ₁ - x ₀ )/2 D ₁ = (y ₁ - y ₀ )/2 D ₂ = (x ₁ - x ₂ )/2 Similar differential signals D ₀ ', D ₁ ′,
Consider D ₂ ′. D ₀ ′=(x ₁ ′−x ₀ ′)/2 D ₁ ′=(y ₁ ′−y ₀ ′)/2 D ₂ ′=(x ₁ ′−x ₂ ′)/2 These difference signals are A characteristic of the color signals of the NTSC system is that they all have the same polarity. FIG. 8A is a signal sequence of the color signal of FIG. 7A itself, and shows a part of the color signal at a certain level. B and C in the same figure are two examples showing breaks in the color signal, and the change in C in the same figure is sharper than that in B in the same figure. Difference _{signals D 0 , D 1 ,}
When calculating D ₂ , the results are as shown in Table 1.

[Table] On the other hand, it is rare for a luminance signal to have a polarity arrangement for each field and each line as shown in FIG. 6, and the present invention uses each of the properties of the color signal and luminance signal described above. 9A to 9D are signal sequences of luminance signals, in which A shows a constant level and B to D show edge portions of the signal. _{Difference signals D 0 , _}
Calculating D ₁ and D ₂ results in the results shown in Table 2.

[Table] As is clear from Tables 1 and 2, each difference signal in the case of color signals is a positive value, but in the case of luminance signals, some of the difference signals are zero, and at the same time they are positive. There is nothing of value. By the way, regarding signal separation using three sample points x ₀ , x ₁ , and x ₂ in the current field, the present applicant previously proposed Japanese Patent Application Nos. 1986-66441, 1983-66442, and 1982
As a method for determining the presence of a color signal in patent application No. 66443 for "Signal Separation Device", the following conditional expression Q={D ₀ +D ₂ +β ₁ (D ₀ −D ₂ )}・{D ₀ +D ₂ −β ₁ (D ₀ −D ₂ )}>0 However, it was proposed to use 1<β ₁ ≦3. In addition to this, in the present invention, from Tables 1 and 2, P ₁ = (β ₂ D ₁ +D ₀ )・(β ₂ D ₁ −D ₀ )≧0 P ₂ =(β ₂ D ₁ +D ₂ )・(β ₂ D ₁ −D ₂ )≧0 However, two conditional expressions, β ₂ ≧2 and D ₁ =(y ₁ −y ₀ )/2, are used to determine the presence of a color signal. β ₁ and β ₂ in the above conditional expressions Q, P ₁ and P ₂ are obtained from Tables 1 and 2. Color signal condition Q>0
From Table 1, the condition for β ₁ for
In Figure A, there is no particular fixed value, and in Figures B and C, β ₁ <3. Furthermore, as shown in Table 2, the condition for β ₁ for the brightness signal condition Q≦0 to hold is that there is no fixed value in FIG. 9A, and β ₁ ≧1 in FIG.
It is. Accordingly, β ₁ must be set to 1≦β ₁ <3. However, since β ₁ = 1 is related to the boundary between the luminance signal and the color signal, the range of β ₁ is set to 1<β ₁ in order to improve the degree of separation between the two.
Make it <3. On the other hand, from Table 1, the condition for β ₂ for P ₁ ≧0 and P ₂ ≧0 to simultaneously hold is β ₂ ≧2. or,
From Table 2, β ₂ satisfies P ₁ ≧0 and P ₂ ≧0 at the same time.
conditions cannot be obtained. Therefore, the color signal and the luminance signal can be determined by the conditions of Q, P ₁ and P ₂ and the settings of their parameters β ₁ and β ₂ . In the present invention, the conditions Q, P ₁ , and P ₂ are used as color signal determination conditions, and the operation thereof will be explained below. FIG. 1 shows a block system diagram of an embodiment of the apparatus of the present invention. Consider the case where the color signal s shown in FIG. 10A and the luminance signal s shown in FIG. 12A are input to the terminal 1. The representation of each signal is shown in Figure 17 and 1.
As in FIG. 8, a vertical sample point array is used, and a signal exists in, for example, five lines in each of the current field and the previous field. The color signal s (FIG. 10A) is passed through the bandpass filter 12.
(The center frequency is _S c and the band is ±500kHz), and the sample points (● marks) of the current field are
The signal x 2 is filtered to an order of magnitude that can be ignored (according to the scale of the figure) and becomes the signal x ₂ (B in the same figure).
Signal x ₁ in 1H delay circuit 13 (C in the same figure), signal x ₀ in 1H delay circuit 14 (D in the same figure), 261H delay circuit 15
Signal y ₁ (E in the same figure), signal at 1H delay circuit 16
y ₀ (F in the same figure). Here, y ₁ and y ₀ are the previous fields, that is, y ₁ is the sample point 262H before x ₁ , y ₀ is the sample point 263H before x ₁ , and the sample point in the previous field of the 10th stroke A ( Γ mark). The signals x ₁ and x ₂ are processed by the subtracter 17 as {(x ₁ −x ₂ )/2}
is calculated and becomes the above-mentioned D ₂ (G in the same figure), and the signals x ₁ ,
The subtracter 18 calculates x ₀ as {(x ₁ - x ₀ )/2} to obtain the signal D ₀ (H in the figure), and the subtracter 19 calculates the signals y ₁ and y ₀ as {(y ₁ −y ₀ )/2} is calculated and the signal is
D ₁ (I in the figure) and are supplied to the color signal determination circuit 20 and color signal setting circuit 21, respectively. FIG. 2 shows a specific circuit diagram of the color signal determination circuit. In the figure, the signals D ₀ and D ₂ are converted into a signal (D ₀ −D ₂ ) (J in the figure) by the subtracter 22, and the signals D ₀ and
D ₂ is converted into a signal (D ₀ +D ₂ ) (K in the figure) by the adder 23. The signal (D ₀ −D ₂ ) is weighted by β ₁ in the amplifier 24 to become the signal β ₁ (D ₀ −D ₂ ), and the signal β ₁ (D ₀ −D ₂ ) is weighted by the adder 25 as described above. ( _D0 + _D2 )
is added to the signal (D ₀ + D ₂ ) + β ₁ (D ₀ - D ₂ ) (L in the figure), while the subtracter 26 adds the signal (D ₀ +
D ₂ ) and the signal (D ₀ + D ₂ ) − β ₁ (D ₀ −
D ₂ ) (M in the same figure). Signal (D ₀ + D ₂ ) + β ₁ (D ₀
−D ₂ ), (D ₀ +D ₂ )−β ₁ (D ₀ −D ₂ ) are multiplied by the multiplier 27 to produce a signal Q={D ₀ +D ₂ +β ₁ (D ₀ −D ₂ )}・{ D ₀ +D ₂ −β ₁ (D ₀ −D ₂ )} (N in the same figure). The signal Q is supplied to a comparator 28 and compared with a reference value of zero, and a 1-bit signal Q (W in the figure) is taken out, which is 0 if Q>0 and 1 if Q≦0. The signal D ₁ is weighted by β ₂ (for example, 2.5 from the condition of β ₂ ≧2) in the amplifier 29, and the signal D _{1 is}
(O in the figure), and the signal β ₂ D ₁ is added to the signal D ₀ in the adder 30 to obtain the signal (β ₂ D ₁ +D ₀ ) (P in the figure), The signal D ₀ is subtracted to obtain a signal (β ₂ D ₁ −D ₀ ) (Q in the same figure). The signals (β ₂ D ₁ +D ₀ ) and (β ₂ D ₁ −D ₀ ) are multiplied by the multiplier 32 and the signal P ₁ =(β ₂ D ₁ +D ₀ )(β ₂ D ₁ −D ₀ )( R) in the same figure. Similarly, the signal D ₁ is converted to β ₂ by the amplifier 33.
The signal β ₂ D ₁ is weighted to form a signal β 2 D 1 (S in the same figure), and the signal β ₂ D ₁ is added to the signal D ₂ in an adder 34 to produce a signal (β ₂ D ₁ +D ₂ ) (T in the same figure). On the other hand,
The subtracter 35 subtracts the signal D ₂ to obtain the signal (β ₂ D ₁
−D ₂ ) (U in the same figure). Signal (β ₂ D ₁ + D ₂ ),
(β ₂ D ₁ −D ₂ ) is multiplied by the multiplier 36 to obtain a signal P ₂ =(β ₂ D ₁ +D ₂ )(β ₂ D ₁ −D ₂ ) (V in the figure). Note that since only the polarity information of P ₁ and P ₂ is used in the subsequent circuit, assuming that 0 and positive data are 0 and negative data is 1, P ₁ and P ₂ are the signals shown in X and Y in the same figure, respectively. They are assumed to be P ₁ and P ₂ . Signals Q, P ₁ and P ₂ are converted into signal Z (Z in the figure) by a 3-input NOR gate 37 composed of, for example, two 2-input OR gates and one NOR gate, and the first
The signal is supplied to a switch circuit 38 in the figure as a switching control signal. In other words, the color signal determination signal 20 is the signal D ₀ ,
It outputs 1 when D ₁ and D ₂ have the same sign, and the first
In FIG. 0 Z, the 1 part is a color signal, and the 0 part is a luminance signal or no signal. On the other hand, FIG. 3 shows a specific circuit diagram of the color signal setting circuit 21. As shown in FIG. In the same figure, the signals D ₁ and D ₀ are converted into a signal (D ₁ +D ₀ ) (FIG. 11A) by an adder 39, and are converted into a signal (D ₁ −D ₀ ) (FIG. 11B) by a subtracter 40. These are converted into a signal (D ₁ +D ₀ ) by the multiplier 41.
(D ₁ −D ₀ ) (C in the same figure) and data selector 4
5. The signals D ₀ and D ₂ are converted into a signal (D ₀ +D ₂ ) (D in the same figure) by the adder 42, and converted into a signal (D ₀ −D ₂ ) (E in the same figure) by the subtracter 43, and these are The multiplier 44 converts the signal into a signal (D ₀ +D ₂ ) (D ₀ −D ₂ ) (FIG. F) and supplies it to the data selector 46 . The signals D ₁ and D ₀ are supplied to the data selector 45 and the output signal of the multiplier 41 (D ₁ +D ₀ ) (D ₁ −D ₀ )
When is 0 and positive (ie, MSB=0), the signal D ₁ is selected, and when it is negative (ie, MSB=1), the signal D ₀ is selected. That is, the one with the larger absolute value of the signals D ₁ and D ₀ is selected and taken out as the signal W ₁ (G in the figure). On the other hand, the signals D ₀ and D ₂ are supplied to the data selector 46 and the output signal (D ₀
+D ₂ ) (D ₀ −D ₂ ) is 0 and positive (i.e.
MSB=0) signal D ₀ is selected and when negative (i.e.
MSB=1) Signal _D2 is selected. That is, the signal
The one with the larger absolute value of D ₀ and D ₂ is selected and taken out as the signal W ₂ (H in the figure). Signals W ₁ and W ₂ are converted into signals (W ₁ +
W ₂ ) (I in the same figure), and the subtracter 48 outputs a signal (W ₁ - W ₂ ) (J in the same figure), which is sent to the multiplier 4.
At step 9, the signal (W ₁ +W ₂ ) (W ₁ -W ₂ ) (K in the same figure) is converted into a signal and supplied to the data selector 50 . signal
W ₁ and W ₂ are supplied to the data selector 50 and the output signal (W ₁ +W ₂ ) (W ₁ −W ₂ ) of the multiplier 49 is 0.
When it is positive (i.e., MSB=0), the signal W ₁ is selected, and when it is negative (i.e., MSB=1), the signal _{W 2} is selected, and the switch circuit in FIG. Supplied to W ₃ . In other words, the color signal setting circuit 2
1 outputs the signal with the largest absolute value among the signals D ₀ , D ₁ , and D ₂ . In the switch circuit 38, the color signal determination circuit 2
When the output signal z of 0 (Z in FIG. 10) is 1, the output signal W ₃ of the color signal setting circuit 21 is selected, and when the signal z is 0, the zero potential is selected, and the signal m (M in FIG. 11) is selected.
is extracted as The signal m is passed through a band filter 51 similar to the band filter 12 to the color signal setting circuit 2.
1. The switching noise generated in the switch circuit 38 is reduced, and the reproduced color signal C (N in the same figure)
The signal is taken out from the output terminal 6 as a signal. On the other hand, terminal 1
The incoming color signal s (FIG. 10A) is delayed by 1H in the 1H delay circuit 52, and the delay circuit 53 corrects the arithmetic processing time etc. in the band filters 12 and 51 to produce the signal o (FIG. 11A). ), and the subtractor 54
The signal C from the bandpass filter 51 is subtracted from the signal Y (P in the figure), which is taken out from the output terminal 11. As is clear from the color signal C shown in Figure N and the signal Y shown in Figure P, only the color signal is taken out from terminal 6, and no distortion component is taken out from terminal 11, compared to the conventional device. Color and luminance signals can be completely separated and extracted. The color signals C and Y shown in FIG. 11 Q and R are at the sample points of the next field to the current field that has been explained so far, and it can be seen that these are also only color signals and no distortion components are extracted. . Next, the luminance signal s (FIG. 12A) that has entered the terminal 1 is processed through the same route as in the case of the color signal. Each signal shown in FIGS.
The signals correspond to the signals shown in FIGS. A to Z, and the signals shown in FIGS. 13A to R correspond to the signals shown in FIGS. 11A to R. As is clear from the luminance signal Y shown in FIG. 13P and the signal C shown in FIG. The color signal and luminance signal can be completely separated and extracted. The luminance signal Y and the signal C shown in FIG. 13 Q and R are at the sample points of the next field to the current field, and it can be seen that these are also only luminance signals and no distortion components are extracted. Since the operation of each circuit can be easily understood from the above explanation of the color signal, the explanation thereof will be omitted. Effects of the Invention The device of the present invention obtains differential signals D ₀ =(x ₁ −x ₀ )/2, D ₁ =(y ₁ −y ₀ )/2, D ₂ =(x ₁ −x ₂ )/2. and under the conditions of 1<β ₁ <3, β ₂ ≧2 {D ₀ +D ₂ −β ₁ (D ₀ −D ₂ )}・{D ₀ +D ₂ +β ₁ (D ₀ −D ₂ )} >0, ( _{β2D1 - D0} )( _β2D1 + _D0 )≧0, ( _{β2D1 - D2} )( _{β2D1 + D2 )} ≧0 are simultaneously established. _a means _for generating a color signal judgment signal using the color signal judgment signal;
Since the configuration includes means for obtaining an output color signal from D ₂ and means for obtaining an output luminance signal by subtracting the output color signal from a signal in which the input color video signal is delayed by one horizontal scanning period, the color signal and luminance signal are Both do not contain distortion components, and can be extracted completely independently.Therefore, there is no interference such as cross color at vertical edges, and the image quality is improved compared to conventional ones. It has features such as obtaining.

[Brief explanation of drawings]

Fig. 1 is a block system diagram of an embodiment of the device of the present invention, Figs. 2 and 3 are specific circuit diagrams of the main parts of the device of the present invention, and Figs. 4 to 7 show signals, sample points, and samples. Figures 8 and 9 are diagrams for explaining the relationship between values, Figures 8 and 9 are diagrams of color signals and luminance signals, respectively, Figures 10 to 13 are signal diagrams for explaining the operation of the device of the present invention,
Figures 14 and 15 are diagrams for explaining signal separation states and color subcarrier diagrams, Figure 16 is a block system diagram of an example of a conventional device, and Figures 17 and 18 are for explaining the operation of the conventional device. FIG. 1... Color video signal input terminal, 6... Color signal output terminal, 11... Luminance signal output terminal, 12, 5
1...Band filter, 13, 14, 16, 52...
...1H delay circuit, 15...261H delay circuit, 17~
19, 22, 26, 31, 35, 40, 43, 4
8, 54...subtractor, 20...color signal determination circuit,
21...Color signal setting circuit, 23, 25, 30, 3
4, 39, 42, 47... Adder, 24, 29,
33...Amplifier, 27, 32, 36, 41, 4
4, 49... Multiplier, 28... Comparator, 37...
Noah Gate, 38...Switch circuit, 45,4
6, 50...data selector, 53...delay circuit.

Claims (1)

[Claims] 1. The color signal is obtained by signal processing by sampling every horizontal scanning period from an input color video signal of the NTSC system, which includes a color signal whose polarity is inverted every horizontal scanning period and a luminance signal whose polarity is not inverted. and the luminance signal, a sampling point at which the color signal and the luminance signal are located is x ₁ , a sampling point one horizontal scanning period before the sampling point x ₁ is x ₀ , and the sampling point The sampling point after 1 horizontal scanning period of x ₁ is x ₂ , the sampling point 262 horizontal scanning periods before the sampling point x ₁ is y ₁ , the sampling point ₂₆₃ horizontal scanning periods before the sampling point x 1 is y ₀ , means for obtaining differential signals D ₀ =(x ₁ −x ₀ )/2, D ₁ =(y ₁ −y ₀ )/2, D ₂ =(x ₁ −x ₂ )/2, and 1 <β ₁ <3, β ₂ ≧2 under the conditions {D ₀ +D ₂ −β ₁ (D ₀ −D ₂ )}・ {D ₀ +D ₂ +β ₁ (D ₀ −D ₂ )}>0, ( The color signal is determined by detecting that β ₂ D ₁ −D ₀ )(β _{2 D 1} +D ₀ )≧0 and (β ₂ D 1 −D ₂ )(β ₂ D ₁ +D ₂ )≧0 hold simultaneously. means for generating a signal, and the difference signal D ₀ when the color signal determination signal is generated;
It is characterized by comprising means for obtaining an output color signal from _D1 and _D2 , and means for obtaining an output luminance signal by subtracting the output color signal from a signal obtained by delaying the input color video signal by one horizontal scanning period. signal separation device. 2. From an NTSC input color video signal containing a color signal whose polarity is inverted every horizontal scanning period and a luminance signal whose polarity is not inverted, the color signal and the luminance signal are processed by signal processing by sampling every horizontal scanning period. In the signal separation device that separates the above-mentioned color signal and the above-mentioned luminance signal, x ₁ is the sample point, x ₀ is the sample point one horizontal scanning period before the sample point x ₁ , and 1 horizontal scan of the sample point x ₁ is used. When the sampling point after the period is x ₂ , the sampling point 262 horizontal scanning periods before the sampling point x ₁ is y ₁ , and the sampling point 263 horizontal scanning periods before the sampling point x ₁ is y ₀ , the difference signal is Means for obtaining D ₀ =(x ₁ −x ₀ )/2, D ₁ =(y ₁ −y ₀ )/2, D ₂ =(x ₁ −x ₂ )/2, and 1<β ₁ <3, Under the condition of β ₂ ≧2, {D ₀ +D ₂ −β ₁ (D ₀ −D ₂ )}・ {D ₀ +D ₂ +β ₁ (D ₀ −D ₂ )}>0, (β ₂ D ₁ −D ₀ ) (β ₂ D ₁ +D ₀ )≧0 and (β ₂ D ₁ −D ₂ )(β ₂ D ₁ +D ₂ )≧0 are established simultaneously, and a means for generating a color signal determination signal; , color signal setting means for selecting the one with the largest absolute value among the difference signals D ₀ , D ₁ , and D ₂ , and means for obtaining an output color signal from the color signal setting means when the color signal determination signal is generated; A signal separation device comprising means for subtracting the output color signal from a signal obtained by delaying the input color video signal by one horizontal scanning period to obtain an output luminance signal.