JPH067683B2 - Luminance signal / color signal separation filter - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminance signal / color signal separation filter for separating a luminance signal and a color signal from a standard system composite color television signal.

[Conventional technology]

Since luminance information and color information are sent as a frequency-multiplexed composite signal in the current color television standard system, it is necessary for the receiver to correctly separate this information into a luminance signal and a color signal.

In the NTSC system composite color television signal, S is a color obtained by quadrature-modulating a luminance signal Y and two color difference signals U and V (or I and Q) to a color subcarrier frequency f _sc as shown in the following equation (1). It is a composite signal with the signal C.

S = Y + C = S + Usin (2πf _SC t) + V _cos (2πf _SC t)… (1) Where, frame frequency f _F (30Hz), field frequency
If f _V (60 Hz) and horizontal scanning frequency f _H (15.75 KHZ), then the relationship between these frequencies and the color subcarrier frequency f _SC is given by the following equation (2).

Therefore, when the NTSC composite color television signal is synchronously sampled at a sampling frequency f _{S that} is four times the color subcarrier frequency f _SC , the sampling signal sequence is displayed on the screen as shown in FIG.
Takes a dimensional array. That is, the phase of the color signal C is inverted by 180 ° line by line, and the color subcarrier 1
The sampling signal of 4 samples is extracted during the period.

Furthermore, PAL system composite color television signal P, when the color subcarrier frequency f _'SC, is expressed by the following equation (3).

P = Y + Usin (2πf ' SC t) ± Vcos (2πf' SC t) ... (3) where the switching of the sign ± is even scan lines +, in odd scan lines - to become. That is, the V component is inverted for each scanning line.

In addition, frame frequency f ′ _F (25Hz), field frequency
Assuming f ′ _V (50 Hz) and horizontal scanning frequency f _H (15.625 KHz), the relationship between these frequencies and the color sub-carrier frequency f ′ _SC is given by the following equation (4).

That is, the color subcarrier frequency f _'SC and the horizontal scanning frequency f _H
Has a 1/4 line offset relationship. Therefore, the PAL system composite color television signal is converted to the color subcarrier frequency f ′.
A sampling signal sequence synchronously sampled at a sampling frequency f ′ _{S which} is four times as high as _SC takes a two-dimensional array as shown in FIG. 6 on the screen. That is, the phase of the color signal is the same every four line cycles.

On the other hand, in order to make the color television signal compatible with the black-and-white television signal, the composite color television signal containing the color signals frequency-multiplexed so that the spectrum is frequency-interleaved within the band of the luminance signal is accurate in the receiver Y for separating the luminance signal Y and the color signal C into
It requires a C separation film.

As a luminance signal / color signal separation filter of this type, the one shown in FIG. 7 is conventionally known.

In the figure, (1) is a composite color television input signal sequence (101) sampled synchronously with the color subcarrier at the sampling frequency.
Is input, the input signal sequence (101) is delayed by one line and a one-line delay signal (102) is output, and (2) is a one-line delay of the first one-line delay circuit. The signal (102) is input and this 1 line delay signal (102)
1 run-in delay circuit for delaying 1 line to output a 2 line delay signal (103), (3) is the input signal sequence (101),
The vertical filter (4), to which the 1-line delay signal (102) and the 2-line delay signal (103) are input, and which outputs the line-seeding signal (104) which carries out the seeding for each line including the color signal, The horizontal bandpass filter that receives the line crossing signal (104) of this vertical filter and separates the color signal that is the high frequency component from this line crossing signal (104) and outputs the color signal (105). , (5) are 1 line delay signal (102) and color signal (10
5) is input, and is a subtracter that separates a color signal from the 1-line delay signal (102) and outputs a luminance signal (106).

Next, the operation of the luminance signal / color signal separation filter configured as described above will be described. First, the operation for the NTSC composite color television signal will be described.

In this case, the sampling frequency f _S = 4 · f _SC in synchronized sampling on Iro含carrier composite color television input signal series (10
1) becomes a two-dimensional grid-like array on the screen as shown in FIG.
Also, Z ⁻¹ and Z ^−l are used as a symbol representing the delay of 1 sample and the delay of 1 line by using Z conversion. Where Z ^-1 = exp {-j2πf / 4f ^SC }, and Therefore, l = 910.

Now, in the first delay circuit (1), the composite signal S (m, n + 1) in the composite color television input signal sequence (101) shown in FIG.
Is entered. At this time, the 1-line delay signal (102) from the first delay circuit (1) is S (m, n), and the 2-line delay signal (103) from the second delay circuit (2) is S (m , n-1). These composite signals S (m, n + 1), 1-line delay signals S (m, n,
n) and 2 run delay signals S (m, n-1) are vertical filters.
The line crossing signal (104) which is input to (3) and crossed for each line including the color signal is extracted by the vertical direction filter (3). The transfer function H _V (Z) of the vertical filter (3) is Is. That is, in this vertical direction filter (3), it is considered that the television signals are similar between the adjacent pixels, and the line crossing signal (104) at the coordinates (m, n) is displayed on the screen shown in FIG. It is extracted as H _C (m, n) represented by the following equation (5).

Since this line crossing signal H _C (m, n) contains a luminance signal, the color signal that is the high frequency component is separated from H _C (m, n) by the horizontal hand-pass filter (4). It is to be output as C (m, n) (105). The transfer function H _h (Z) of the horizontal bandpass filter (4) is, for example, Is.

On the other hand, the 1-line delay signal S (m, n) from the first delay circuit (1) and the color signal (m, n) from the horizontal band pass filter (4) are input to the subtractor (5). The luminance signal (106) is output as Y (m, n) represented by the following equation (6).

Y (m, n) = S (m, n) -C (m, n) (6) Next, the operation for the PAL system composite color television signal will be described.

In this case, the composite color television input signal sequence (1) sampled synchronously with the color-containing carrier at the sampling frequency f ′ _S = 4 · f _SC
In 01), the color signal phases are arranged on the screen as shown in FIG. That is, the phase of the color signal returns in a cycle of four lines, the color signal component in which the phase of the color subcarrier changes by 180 ° corresponds to the preceding line for the even line, and the phase of 180 ° for the odd line. The changing color signal component corresponds to the next line. Therefore, to get the PAL system 4 line alternation signal H _'C corresponding to the NTSC system line alternation signal (104) by the signal processing in the vertical direction filter (3) by switching the operation on the odd lines and even lines There is something. Line alternation signal when the _{H 'C (m, 2n-} 1) and H' _C (m, 2n) is expressed by the following formula (7) (8).

Odd line; Even lines; That is, the line crossing signal (104) is extracted using the upper and lower sample points that form a set for every two lines, and the color signal C (m, n) is extracted through the horizontal band pass filter (3). In addition, the luminance signal is taken out as the luminance signal Y (m, n) from the arithmetic unit (5).

[Problems to be solved by the invention]

In the luminance signal / color signal separation filter configured in this way, the fixed vertical direction filter () is used on the assumption that the pixels, which are the sample conversion rows of the composite color television signal, are adjacent to each other on the screen. 3) and a horizontal band pass filter (4) are combined.

However, in such a case, in an area where the brightness and color of the image change drastically, the luminance signal and the color signal leak to each other's channel, so the reproduced image such as color turbidity due to cross color or dot interference However, there was a problem that the disturbance of

The present invention has been made in view of the above points, and an object thereof is to obtain a luminance signal / color signal separation filter capable of obtaining a luminance signal and an immediate signal with little cross color and dot interference from a composite color television signal. It is a thing.

[Means for solving problems]

The luminance signal / color signal separation filter according to the present invention is input with a composite color television input signal, and is close to the input signal in the upward direction on the screen, and the phase of the color subcarrier is the phase of the color subcarrier of the input signal. A display signal that is deviated from the phase by π radians, and first to third samples that are close to the display signal in the left and right directions on the screen and the phase of the color subcarrier is deviated from the phase of the color subcarrier by π radian Between the sample point signal generating means for generating a point signal and the above-mentioned input signal as the fourth sample point signal and the first to third sample point signals are inputted, and between these first to fourth sample point signals. Of the first to fourth sample point signals based on the selector control signal output from the selector control signal corresponding to the combination of the sample point signals corresponding to the minimum difference absolute value Minimum difference A selector that selects and outputs two sample point signals that form a combination of sample point signals that are pairs of values, and a display signal from the sample point signal generating means that doubles the display signal by the two sample point signals from the selector. A separation filter that separates and outputs a color signal by multiplying a signal that is obtained by subtracting two sampling point signals from a signal, and a subtractor that subtracts a color signal from the display signal and outputs a luminance signal. Is provided.

[Action]

In the present invention, the sampling point signal generating means generates the display signal and the first to third sampling point signals based on the input signal, and the comparing and judging means and the selector use the input signal as the fourth sampling point signal. Two sample point signals having the smallest absolute difference are selected by the sample point signals, the color signal is separated from the display signal based on the selected two sample point signals, and the luminance is displayed from the display signal based on the color signals. You get the signal.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS. In the figure, (6) is sampled synchronously to the color subcarrier at the sampling frequency and the composite color television input signal series (101) is input.
In the first variable line delay means for outputting a signal (107) delayed by 2 samples less than one line in the case of the system, and delayed by 2 samples less than 2 lines in the case of the PAL system, For example, it is composed of a shift register.In this case, the number of clocks until the data input to the input end is output to the output end is 108 clocks in the NTSC system and 2268 clocks in the PAL system. Yes, it is configured so that both clock numbers can be switched. Reference numeral (7) is a first dot delay means for inputting the signal (107) of the first variable line delay means and outputting this signal (107) as a signal (102) delayed by two samples. It is composed of a shift register. In this case, the number of clocks until the data input to the input end is output to the output end is 2 clocks.
(8) is a signal obtained by inputting the signal (102) of the first dot delay means and delaying this signal (102) by 2 samples.
The second dot delay means for outputting as (108)) is constituted by the same as the first dot delay means (7). (9)
Is inputted with the signal (108) of the second dot delay means,
In case of NTSC system, this signal (108) is 2 from 1 line.
In the case of the PAL system, the second variable line delay means for outputting a signal (103) delayed by two samples less than two lines in the case of the PAL method, is the first variable line delay means ( It consists of the same as 6). For convenience of explanation, the signal (102) output from the first dot delay means (7) is the display signal, and the second dot delay means (8).
The signal (108) output from the first sampling point signal, the signal (107) output from the first variable line delay means (6) is the second sampling point signal, and the second variable line delay means (9) The signal (103) output from the above is referred to as a third sampling point signal, and the signal (101) input to the first variable line delay means (6) is referred to as a fourth sampling point signal. (10) is the first from the second dot delay means (8)
Sample point signal, second from the first variable line delay means (6)
Sample point signal, third from second variable line delay means (9)
The sampling point signal and the fourth sampling point signal which is the input signal sequence (101) are input, the absolute value of the difference between these first to fourth sampling point signals is calculated, and the sampling point signal which becomes the minimum absolute difference value is obtained. According to the comparison / determination means for outputting the selector control signal (109) in response, in this embodiment, the absolute value of the difference between the first and third sampling point signals, the absolute value of the difference between the first and fourth sampling point signals, The absolute value of the difference between the second and third sample point signals and the absolute value of the difference between the second and fourth sample point signals are compared and determined, and the configuration shown in FIG. 2 is used. is there. In Fig. 2 (10A
₁ ) is the first subtractor that receives the first sample point signal and the third sample point signal and outputs the difference between these signals, and (10A ₂ ) is the first sample point signal and the fourth sample point signal that are input, The second subtractor that outputs the difference between these signals, (10A ₃ ) is the _third subtractor that receives the second sample point signal and the third sample point signal, and outputs the difference between these signals, (10A ₄ ) is the A fourth subtracter, which receives the two-sample-point signal and the fourth-sample-point signal and outputs the difference between these signals, (10B ₁ ) to (1
0B ₄ ) is a first to fourth absolute value circuit that outputs the absolute value of the difference signal from these first to fourth subtractors, and (10C ₁ ) is the first and second absolute value circuits.
A first digital comparator (10C ₂ ) receives the differential absolute value signal from the absolute value circuit, compares these signals, and outputs a determination output signal according to the smaller differential absolute value signal. 4 The second digital comparator (10D ₁ ) receives the difference absolute value signal from the absolute value circuit, compares these signals, and outputs the judgment output signal according to the smaller difference absolute value signal. First switch means for switching and outputting the difference absolute value signal of the value circuit (10B ₁ ) and the difference absolute value signal of the second absolute value circuit (10B ₂ ) based on the judgment output signal of the first digital comparator (10C ₁ ). , (10D ₂ ) is the above 8th
The absolute value signal of the absolute value circuit (10B ₃ ) and the fourth absolute value circuit (1
0B ₄ ) and a differential absolute value signal of the second digital comparator (10C ₂ ) are switched and output based on the determination output signal of the second digital comparator (10C ₂ ), and (10C ₃ ) is the first and second switch means (10D).
₁ ) A third digital comparator that receives the difference absolute value signal from (10D ₂ ), compares these signals and outputs a judgment output signal according to the smaller difference absolute value signal, (10E) is the first digital comparator. A selector control signal generation circuit which receives the judgment output signal of the third digital comparator and outputs selector control signals (109a) (109b) for selecting the two sampling point signals having the minimum absolute difference value.

(11) is the first sampling point signal from the second dot delay means (8), the second sampling point signal from the first variable line delay means (6), and the second variable line delay means (9) From the four sampling point signals based on the selector control signal (109) from the comparing and judging means (10). A selector for selecting and outputting two sample point signals, which has the configuration shown in FIG. 3 in this embodiment. Third
In the figure, (11a) is the selector signal (109a) from the selector control signal generation circuit (10E) of the selector (10), in which the first, third, and fourth sampling point signals are connected to the respective input terminals. The first signal S ₁ (11
The first switching switch means for outputting as (0), (11b) the second, third, and fourth sampling point signals are connected to the respective input terminals,
The selector signal (109b) from the selector control signal generation circuit (10E) of the selector (10) outputs one of the second, third and fourth sampling point signals as the second signal S ₂ (111). It is a second switching switch means.

(12) is the first and second signals S ₁ , S ₂ from the selector (11)
Separation filters for inputting the display signals from the (110) and (111) and the first dot delay circuit (7) and outputting the color signals (105). In this embodiment, they have the structure shown in FIG. . In FIG. 4, (12A) is an adder composed of an n-bit adder for adding the first and second signals S ₁ , S ₂ (110) (111) from the selector (11), and (12B) is the adder. Bit shift that doubles the display signal from the 1-dot delay circuit (7), (12C)
Is a subtracter to which the output from the adder (12A) and the output from the dot shift (12B) are input, and (12D) is a bit shift for multiplying the output from the subtractor by 1/4.

Next, the operation of the luminance signal / color signal separation filter configured as described above will be described. First, the operation for the NTSC composite color television signal will be described.

The first variable line delay means (6) has a sampling frequency f _S = 4f _SC
At, the sampling sequence (101) of the composite color television signal synchronously sampled with the color subcarrier is input. Now, it is assumed that the signal S (m, n + 1) for displaying the coordinates (m, n + 1) shown in FIG. 5 is input as the signal of the sampling sequence (101). This signal S (m, n + 1) becomes the fourth sampling point signal S (m, n + 1). The second (107) output from the first variable line delay means (6) at this time
The sampling point signal is S (m + 2, n), and the first dot delay means (7)
The output signal (102) from the display signal is S (m, n)
The first sampling signal which is the output (108) from the dot delay means (8) is Sm-2, n) and the third sampling which is the output (103) from the second variable line delay means (9). The signal is S (m, n-1).
These first to fourth sampling signals are input to the comparison / determination means (10) and the selector (11). The comparison / determination means (10) uses the absolute values of the differences between the input first to fourth sampling signals, in this embodiment, | S (m-2, n) -S (m, n-1) | , | S (m-
2, n) -S (m, n + 1) |, | S (m + 2, n) -S (m, n-1) |, | S (m +
2, n) -S (m, n + 1) |, and a selector having the smallest absolute difference value, for example, a combination of S (m-2, n) and S (m, n-1) The signal (109) is output. On the other hand, in the selector, two sampling signals of the first to fourth sampling signals that have been input are selected based on the selector signal (109) from the comparison and determination means (10) to select the first and second signals S. Output as ₁ and S ₂ . The first and second signals S ₁ and S ₂ are converted into S by the comparison and determination means (10).
When a combination of (m-2, n) and S (m, n-1) is selected,
S (m-2, n) and S (m, n-1). And this selector
The separation filter (12) receives the first and second signals S ₁ and S ₂ from (11) and the display signal from the first dot delay means (7), and the color signal C shown by the following equation (9) is obtained. Output _N (m, n) as a signal (105).

C _N (m, n) = (-S ₁ + 2S (m, n) -S ₂ ) / 4 (9) On the other hand, the subtracter (5) outputs the signal from the first dot delay means (7). The display signal S (m, n) and the color signal C _N (m, n) from the separation filter (12) are input and the luminance signal (106) is expressed by the following formula (10) Y _N (m, n)
Is output as.

Y _N (m, n) = S (m, n) -C _N (m, n) (10) The luminance signal / chrominance signal separation filter thus constructed has a display signal S ( m, n) using four first to fourth sampling signals that are adjacent in the vertical and horizontal directions,
Since the luminance signal and the chrominance signal are separated by using the sampling signal with less waveform deformation among these sampling signals, a color image with very little cross color interference or dot interference can be obtained. is there.

Next, the operation for the PAL system composite color television signal will be described.

The first variable line delay means (6) has a sampling frequency f _S = 4f ′.
_{At the SC} , a sampling sequence (101) of a composite color television signal that is synchronously sampled on a color subcarrier is input. Now, assume that the signal P (m, 2n + n) for displaying the coordinates (m, 2n + 2) shown in FIG. 6 is input to the signal of the sampling sequence (101). This signal P (m, 2n + n) becomes the fourth sample point signal P (m, 2n + 2). At this time, the second sampling point signal which is the output (107) from the first variable line delay means (6) is P (m + 2,2n), and the output (102) from the first dot delay means (7). ) Is a display signal P (m, 2n), which is the output (108) from the second dot delay means (8).
The sampling signal is P (m-2,2n), and the third sampling signal which is the output (103) from the second variable line delay means (9) is P (m, 2n-).
2). These first to fourth sampling signals are used for comparison and determination means.
It is input to (10) and the selector (11). Comparison judgment means (10)
Then, the absolute value of the difference between the input first to fourth sampling signals, in this embodiment, | P (m-2,2n) -P (m, 2n-
2) |, | P (m-2,2n) -P (m, 2n + 2) |, | P (m + 2,2n) -P
(m, 2n-2) |, | P (m + 2,2n) -P (m, 2n + 2) | is calculated, and the absolute value of these differences is the smallest, for example, P (m-2,2n) P (m, 2n-
The selector signal (109) in combination with (2) is output. On the other hand, in the selector, two sampling signals of the first to fourth sampling signals that have been input are selected based on the selector signal (109) from the comparison and determination means (10) to select the first and second signals S. _P1 ,
Output as S _P2 . The first and second signals S _P1 and S _P2 are output when the combination of P (m-2,2n) and P (m-2,2n-2) is selected by the comparison and determination means (10). Is P (m-2,2n) and P (m, 2n-
2). Then, the separation filter (12) receives the first and second signals S _P1 , S _P2 from the selector (11) and the display signal from the first dot delay means (7), and is represented by the following equation (11). The output color signal C _P (m, 2n) is output as the signal (105).

C _P (m, 2n) = (-S _P1 +2 ・ P (m, 2n) -S _P2 ) / 4 (11) On the other hand, the subtractor (5) has a delay from the first dot delay means (7). The color signal C _P (m, 2n) from the display signal P (m, 2n) and the separation filter (12)
n) is input and the luminance signal (106) is expressed by the following equation (12) Y
It is output as _P (m, 2n).

Y _P (m, 2n) = P (m, 2n) -C _P (m, 2n) (12) The luminance signal / chrominance signal separation filter configured in this way can be used even in the PAL system. , P on the screen
By using four first to fourth sampling signals that are vertically and horizontally adjacent to (m + 2n), and using the sampling signal with the least waveform deformation among these sampling signals, the luminance signal and the chrominance signal are Since the color separation is performed, a color image with very little cross color interference or dot interference can be obtained.

In the above embodiment, the difference absolute value is compared by | S (m-2, n)
-S (m, n-2) |, | S (m-2, n) -S (m, n + 1) |, | S (m + 2,
n) -S (m, n-2) |, | S (m + 2, n) -S (m, n + 1) |, (NTSC
In the case of)), but further | S (m-2, n) -S
It is also applicable to a method of comparing (m + 2, n) | and | S (m, n-1) -S (m, n + 1) | and comparing six.

〔The invention's effect〕

As described above, the present invention provides a luminance signal / color signal separation filter for separating a color signal and a luminance signal from a composite color television input signal synchronously sampled on a color subcarrier at a sampling frequency. When the input signal is input,
Sampling point signals that output the display signal and the first to third sampling point signals that approach the display signal in the left and right upward directions on the screen and the phase of the color subcarrier shifts by π radians from the phase of the color subcarrier of the display signal. The generating means and the input signal are input as a fourth sample point signal, and two sample point signals having the smallest absolute value of difference between these four sample point signals are selected together with the first to third sample point signals. Since the luminance signal and the chrominance signal are separated by the two sampling point signals from this selector, the display signal is displayed on the screen in the left / right / upper / lower direction.
Since the luminance signal and the color signal can be separated by the one having little change in the luminance signal and the color signal in the direction, a color image with little cross color interference or dot interference even in the area where the luminance and color changes of the image are severe. Has the effect of being able to reproduce.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, and FIGS. 2 to 4 are comparison / determination means (10) in FIG. 1, respectively.
FIG. 5 is a block diagram showing the selector (11) and the separation filter.
An explanatory diagram showing an array on the screen of a signal sequence in which one field of an NTSC system composite color television signal is synchronously sampled at four times the color subcarrier frequency, and FIG. 6 is a diagram of a PAL system composite color television signal. FIG. 7 is an explanatory diagram showing an array on the screen of a signal sequence in which the field component is synchronously sampled at four times the color subcarrier, and FIG. 7 is a configuration diagram showing one embodiment of a conventional luminance signal / color signal separation comb filter. Is. In the figure, (5) is a subtractor, (6) is a first variable line delay means, (7) is a first dot delay means, (8) is a second dot delay means, and (9) is a second variable line delay means. Means, (10) comparison / determination means, (11) selector, (12) separation filter, (101) composite color television input signal, (102) display signal, (10)
3) is the third sampling signal, (105) is the color signal, (106) is the luminance signal, (107) is the second sampling signal, (108) is the first sampling signal,
(109) is a selector control signal. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (4)

[Claims] 1. A composite color television input signal synchronously sampled with a color subcarrier at a sampling frequency at which sampling is performed each time the phase of the color subcarrier changes by π radians. On the screen in the upward direction, and the phase of the color subcarrier is shifted by π radians from the phase of the color subcarrier of the input signal, and the display signal approaches the display signal in the left and right upward directions, respectively. Sampling point signal generating means for outputting first to third sampling point signals in which the phase of the color subcarrier is deviated from the phase of the color subcarrier of the display signal by π radian;
The first to third sample point signals from the sample point signal generating means are input, the composite color television input signal is input as a fourth sample point signal, and the input first to fourth sample point signals are input. Comparing / determining means for obtaining at least four different absolute values of the difference and outputting the selector control signal in accordance with the combination of the sampling point signals having the minimum absolute difference value, the first to the first from the sampling point signal generating means. The three sample point signals are input, the composite color television input signal is input as the fourth sample point signal, and the input first to fourth sample point signals are input based on the selector control signal from the comparison and determination means. To a selector that selects and outputs two sample point signals that form a combination of sample point signals that have the minimum absolute difference value, two sample point signals from this selector, and A separation filter for inputting a display signal from the point signal generating means and multiplying a signal obtained by subtracting two sampling point signals from the selector from a signal obtained by doubling the display signal by ¼ to output a color signal. A luminance signal / color signal separation filter provided with a subtracter which receives the color signal from the separation filter and the display signal from the sampling point signal generating means and subtracts the color signal from the display signal to output a luminance signal. 2. The sampling frequency is 4 of the frequency of the color subcarrier.
Double, and composite color television input signal is NTSC
First line delay means for inputting a composite color television input signal to the sampling point signal generating means, delaying this input signal by two samples less than one line, and outputting it as a second sampling point signal. And a first dot delay means for delaying the second sample point signal from the first line delay means by two samples and outputting it as a display signal,
A second dot delay means for delaying the display signal from the first dot delay means by two samples and outputting it as a first sample point signal, and a first sample point signal from the second dot delay means for one line A second line delay means for delaying by two samples and outputting as a third sampling point signal is provided.
The luminance signal / color signal separation filter described in the item. 3. The sampling frequency is 4 of the frequency of the color subcarrier.
And the composite color television input signal is of the PAL system and the sampling point signal generating means receives the composite color television input signal and delays the input signal by two samples less than two lines. First line delay means for outputting as two sample point signals, first dot delay means for delaying the second sample point signals from the first line delay means by two samples and outputting as display signals, and the first line delay means. A second dot delay means for delaying the display signal from the dot delay means by two samples and outputting it as a first sample point signal, and two samples of the first sample point signal from the second dot delay means for two lines. A second line delay means for delaying by a small amount and outputting as a third sample point signal is provided.
The luminance signal / color signal separation filter described in the item. 4. The sampling frequency is 4 of the frequency of the color subcarrier.
The second delay is two times smaller than the first delay by 2 samples less than one line or two samples less than two lines in response to the input signal of the composite color television input signal. Switching operation is performed and the input signal is delayed by the first or second delay
First line delay means for outputting as a sample point signal, first dot delay means for delaying the second sample point signal from the first line delay means by two samples and outputting as a display signal, and the first dot The display signal from the delay means is set to 2
Second dot delay means for delaying by a sample and outputting as a first sampling point signal, and a first delay that is 2 samples less than 1 line or 2 samples less than 2 lines depending on the input signal. And the second line delay means for performing the first or second delay on the first sampling point signal from the second dot delay means and outputting it as the third sampling point signal. The brightness signal / color signal separation filter according to claim 1.