JPS58129891A - Adaptive type luminance signal and chromaticity signal separator - Google Patents

Abstract

PURPOSE:To eliminate the need for a line delay line to correlate in the longitudinal direction, by detecting a pattern before and after a point of a color TV signal, and separating the luminance from the chrominance signal through the use of correlation to a signal having small change of pattern. CONSTITUTION:A color TV signal sampled at a prescribed period Ts is delayed at delay circuits 6-1-6-8 by taking the period Ts as the unit. The signal at a time reference and signals before and after the signal by a prescribed period are inputted to a discrimination circuit 11, the absolute value of the respective signals is taken to discriminate the amplitude and to output a discrimination signal. A plurality of signals before and after the signal at a time reference are inputted to the 1st and 2nd chrominance signal separation circuis 8A, 8B to separate chrominance signals C1, C2. In the selection circuit 12, the chrominance signals C1, C2 are outputted with the discrimination signal through switching. The difference between the output signal and a discrete color TV signal is obtained at a subtraction circuit 16 to obtain the luminance signal Y.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a television device, and more particularly, to a television device.
This relates to a device for separating the luminance signal and color If(!) of an 8C color television signal.

[Technical background of the invention and its problems]

In the NTSC system, when transmitting a color signal, it is modulated with a subcarrier, and the color signal is
It is superimposed on the 4.2MHz part. Also, there is a relationship between the fall carrier frequency (fsc) and the horizontal scanning frequency (bs), and the phase of the subcarrier is 18 for each line.
00 has changed. Therefore, as a method to separate the luminance signal and the chromaticity signal, the NTSC signal is delayed by a half cycle (1/2 fsc) of the sub-transmission wave, and this is added to the signal before the delay, thereby separating the chrominance signal and the chrominance signal. There is a method in which the signals are canceled and only the luminance signal is obtained, and the difference between the two is taken, but the luminance variable signal is canceled and only the chromaticity signal is obtained. This method has the advantage of requiring only a small hardware model because the delay k is small and calculations are simple. In contrast, the separation is not performed properly, resulting in a decrease in resolution.In order to solve this problem, a method of separating using the vertical correlation of the screen has also been used.In other words, when the NTSC signal is By extending the signal by one horizontal period 4!! and adding it to the signal before the delay, the chromaticity signal is canceled from K and a luminance signal is obtained, and by taking the difference between the two, the chromaticity signal is obtained from K. Contrary to the previous example, this method requires a large amount of delay and increases the hardware delay, but separation is performed accurately even for patterns with large changes in the horizontal direction. Disassembly: F's and Ujishita are spared.However, since this method uses the vertical aspect and angle of the screen, the separation is not done properly for patterns that change drastically in the vertical direction. , the vertical resolution will be reduced. Another example is a method in which the signals separated by the two methods described above are combined at an appropriate ratio and output.

According to this method, separation is performed with good performance in both the vertical and horizontal directions, but conversely, the solution *& also decreases in both directions. Also, there is a drawback that the 1-domain pattern becomes large.

[Purpose of the invention]

The present invention has been made in view of this point, and an object of the present invention is to provide luminance signal coloring that can significantly improve the reduction in horizontal resolution caused by separation by using only horizontal correlation. It is said that the company provides a degree signal separation device.

[Summary of the invention]

The present invention uses KL14 to change the separation method depending on the pattern.
Therefore, the luminance signal (
When separating a chromaticity signal (hereinafter referred to as a Y signal) and a chromaticity signal (hereinafter referred to as a C signal), the patterns before and after that point are detected, and the phase (YC separation is performed using electricity) with the signal on the side where the change in the pattern is smaller. This is how it was done.

〔Effect of the invention〕

According to the present invention, there is no need for a line delay line for vertical correlation), and significant savings in hardware are achieved.
, and it is often possible to improve the horizontal resolution without reducing the vertical resolution at all.

[Embodiments of the invention]

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

FIG. 1 is a diagram showing an embodiment of the present invention. The input color television signal 1 is input to a low-pass filter 2. This is a rounding that prevents aliasing during subsequent sampling. Output signal 3 of low-pass filter 2 is input to AD converter 4 and clock generator 18 . The clock generator 18 supplies the burst signal of the color television signal 3 to K as a reference for operation timing. AD converter 4
quantizes the signal 2-television signal 3 (ma(t)) by sample t at the timing of the reference clock 19. That is, the color television broadcast signal 5 can be expressed as m(nTs) (n is an integer) if the finite word length error due to filtering is ignored. The color television broadcast code 5 is input to a delay circuit 6. The delay circuit 6 has a delay time of 1g (=Tsc
/4) unit delay circuits 6-1 to 6-6 are connected in cascade. The signal MA (nOTs) serving as a time reference is the output signal of the unit delay circuit 6-4. Therefore, force 2 - television signal 5 is v((Ig-4)Ts) xma(n□
Ts-Tsc), the unit delay circuit 6-80 output signal is v
(no+4)Ts)=v(ngTs+Tsc), respectively. Figure 2 shows Ma ((no-4)Ts) to V
((n6+4)TI) Sample point “04e” at t
. . 9 is a diagram showing the phase relationship between no+4 and a subcarrier. Sample point 2-2 Line subcarrier 2-1 is sampled every 90''.The color television gene signals 7A, 7B, 7C and 10 delayed by a predetermined time by the delay circuit 6 are colored 1! The signal is input to a mass separation circuit (hereinafter referred to as a C signal separation circuit) 8, 9B, @C and a determination circuit 11.

Color television program code 7 is v(nOTs) and v(((
n.

-'1i)TI), and using this signal, C1
In the 8th round of ISa bribes for M number, in the 9th time to obtain 9 C signals (denoted as CA), CA = -Nv (nOTs) --jv ((no-2
) TI ) ---------------- Perform the calculation in (1). This means that if sample point 11o-no%'i! If the same brightness and chromaticity exist in the range of , the phase of the C signal at these two points will be opposite, and CA
When the correct C signal of v(noTs) is given, it becomes K.

The color television signal 7B is m(n)Ts) and v((
nO+2)TS), and the C signal component - circuit 8B obtains the C signal 9B (denoted as CB).
v(noTS)-1((no+2)Ts)・Song times (2)
Perform the calculation. This means that if the sample points fiO-fi.

If the same brightness and chromaticity exist in the range of +2, then 11 Cm becomes Ma(ngTs
) gives the correct C signal, becomes K. The color TV scene signal 7C is v(n□Ts), v((11g-1)T
s), v ((ng+1)Ts), and in order to obtain the C signal 9C (represented by Cc) in the C signal 41 circuit 8C, CC=v(ngTs)--jvi(no-i)Ts) −
, -v((n□+1)Ts)......(3) This is the sample point no-1-a □+
If the luminance and chromaticity are the same within the range l, then C
c'f'1v(n□Ts) becomes the correct 10 signal. T
Figure s3 is a diagram schematically showing an example of a pattern when the above-mentioned 90 signal separation circuits 8A, 8B, and 8C separate a correct C signal. The 311th p) is an example in which the C signal separation circuit 8m separates a correct C signal when the same luminance chromaticity exists at sample points before sample point nQ. (B) in FIG. 3 is the opposite case to (A), and is an example in which the C signal separation circuit 8B correctly separates the rcC signal.

(C) in FIG. 3 shows an example in which the same luminance and chromaticity exist only at the sample point flQ and two adjacent points, and the C signal separation circuit 8C separates the correct C@ signal. In this way, the patterns before and after the sample point nQ are detected, and tlJ
It is necessary to select the optimal signal from among e cm, cB, and cc given by equation (3). % of this feature
The detection of the pattern is carried out by the judgment circuit 11, and the selection of the signal is carried out by the selection circuit 12.
It will be held in The determination circuit 11 has v(noTs).

A color television signal 10 consisting of v(ng-4)Ts) and v((a□+4)Ts) is input. The determination circuit 11 includes a subtracter 11-1 and an absolute value circuit 1, which performs the following operations.
1-3 l v(nOT's)-v(ng-4)T's
) I (expressed as el) is calculated, and the subtraction 511-2 and the absolute value circuit 11-4 calculate l v(n□Ts) -Y((0g
+4 ) Ts ) l (denoted as C2).

The reference value A and J#c2 are input to a rounding comparison circuit 11-5.6.7 which examines their magnitude relationship. The ratio I2 circuit 11-5.6.7 is e1 and human, el and '2*e, respectively.
2 and the person, and the output signals thereof are outputted as a comparison signal 13 through predetermined gates 11-8, 9, and 10. The comparison signals 13A, 13B, and 13C are (e1≦e2) (el≦A) e (egre
l) (a2≦A).

When (A<el, ez), the level becomes @H” and from then on
outside, it becomes 'L'. This is explained as follows. If the same luminance and chromaticity exist at sample point n Pfig-4, the C signal at sample point rlQ and no-4 are in phase as shown in FIG. 2, and s'1''Ima(n□Ts)-v ((n□-4)T$)I becomes zero OK. This is the case with the pattern shown in the 3111th p).

As mentioned earlier, in this case, Cmu gives the correct number 011. Conversely, if the same brightness change/chromaticity exists at the sample point n g−n g+4, C2=lv(nOTs)−v(
(no+4) Til becomes zero. This is shown in Figure C43 (
In the case of the picture shown in b), CB gives the correct C signal.

Also, if the change in the pattern between sample points no'''404 is large, el will increase, and if the change in pattern O is large between sample points n-g+4, C1 will increase. When the dog is in the dog's mouth, the temple point is n.

It is determined that there is almost no correlation with sample point no-4. Similarly, if Kez>A, it is determined that there is no correlation between sample point no and sample point 1m, +4.

Therefore, if '1se2>mu, it can be determined that the same brightness and chromaticity exist only in the vicinity of sample point no.

this is! In a case like the pattern shown in (c) in diagram s3, the heart is 9.
, at this time, Cc is the most suitable signal. From the above explanation, in the selection circuit 12, the comparison signal 13 is "H" (F), and the comparison signal C is the most suitable signal. 13
B#'H"0IIK is C, comparison signal 13C is 0H"
It is only necessary to output Cc to O#, and this is a piece.) 2-1. The C signal 14 output from the 0 selection circuit 12, which can be realized by the OB gate 2-2, is connected to the output terminal, and at the same time it is connected to the color television signal 15 (in this case, v(nOTs)) which has the same delay time as the C signal 14. ) are both input to the subtracter 16.

Color television') By subtracting the C signal 14 from the W signal 15, the Y signal 17 is obtained. The above is an explanation of the separation of the Y signal and C signal according to one embodiment of the present invention.

The features of the present invention are the above-described determination circuit 11 and selection circuit 1.
This is the adaptive operation performed in step 2. According to this, beak direction phase I
Even though the C signal is separated only by A, based on the detection of the picture, the horizontal force; In other words, the reduction in II4'atL in the horizontal direction is significantly improved without any reduction in the vertical scale change associated with separation. 4g# is no longer required, and hardware is also significantly saved.

Due to recent advances in pooled circuit technology, color television is used. Research on digital television is gaining momentum. Among the components of a digital television, the YC separation circuit according to the present invention can be said to be the most important. Therefore, when converting a circuit into an IC, a separation circuit with good performance and a small hardware mechanism is essential. The present invention meets this requirement and contributes to the use of ICs in digital television.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an embodiment of the present invention, Fig. 2 is a diagram showing the relationship between sample points and the phase of the sub-conveyor skin in an embodiment of the present invention, and Fig. 3 is a diagram showing the relationship between the pattern and the sample points. FIG. 1...Color television signal, 2...Low frequency IA
Filter% 3...Color television signal, 4...
・A/D converter, 5... Color television signal, 6... Delay circuit, 6-1 to 6-8... Unit delay circuit, 7A, 7B, 7C... Color television signal, 8 Human, gB, gc...Chromaticity signal separation circuit, 9A, 9
B, 9C11...judgment circuit, 11=1.11-2...
・Subtractor, 11-3゜11-4... Absolute value circuit, 11
-5 to 11-7... Comparison circuit, 11-8 to 11-10
. . . Φ gate, 12 . . . selection circuit, 12-1 .
・Niyama game), 12-2...OR gate, 13...
Judgment signal, 13 people ~ 13C... Judgment signal, 14...
Iroba signal, 15...Color television signal, 16.
・Reduced version 4.17...Ki 1i1ii: 1, 1B・
...Clock generation circuit, 19...Reference clock, 2-
1...Subcarrier, 2-2 sample points. Agent: Patent attorney Kensuke Chika (and 1 other person)

Claims (1)

[Claims] (1) A sample circuit that samples a color television signal (Y(t)) at a predetermined period (Ts) synchronized with the phase of the color subcarrier; The color television broadcasting signal (v(nTs)
); n integer), and the total delay time for extending the signal by 4 in units of Ts is 2 of the color subcarrier period (Tsc).
Of the discrete color television signal (v(nTs)) delayed by the delay circuit, which is more than twice as long as the delay circuit, the signal on the time basis (v(noTs)) is Tsc Previous and subsequent signals (v(n□Ts-Tsc)
. v(n□Ts-)-Tsc)), and the absolute value is 1.
v (ngT8) - v (nOTs - Tsc) l and absolute value l v (ngTs) - v (n Among the discrete color television signals v(nTs), a plurality of signals (v(kTs); ≦no) before v(ngTs) are input, and the cough signals are each multiplied by a predetermined weighting coefficient and added. a first chromaticity signal separation circuit for separating the chromaticity signals of v(nOTs), and nine of the discrete color television signals (v(nTs)) delayed by the delay circuit; v
Multiple signals after (ngTs) (v(kTs): 4n
g), and the chromaticity 1d of v(n(ITs) is calculated by multiplying each signal by a predetermined weighting coefficient and adding them together.
chromaticity signal (C1) separated by a second chromaticity signal separation circuit that separates the color signal and the first color change signal 1w1l path;
, the nine-color change signal (C2) separated by the second chromaticity signal separation circuit, and the good judgment signal output from the judgment circuit, and the content of the judgment signal is l v (n□Ts
)-v(nOTs-Tsc) l≦l y(n□Ts)
-v(n(ITs-Tsc)l, output C1, lv(ngTs)-v(nOTs-Tsc)l
)lv(ngTs+Tsc) If I, a selection circuit that outputs C2 and a color 1 output from this selection circuit.
1. An adaptive luminance signal/chromaticity signal separation device comprising: a subtraction circuit for subtracting the 1 signal from the 111-color television signal having the same delay time as the cough signal to obtain a luminance signal from K. (2) The chromaticity signal (CI) of the first chromaticity signal separation circuit
>, and the second chromaticity signal separation circuit calculates the chromaticity signal (C
2) The adaptive luminance signal/chromaticity signal separation device according to claim 1, wherein the calculation for obtaining 2) is as follows. 13) The chromaticity signal (CI) of the first chromaticity signal separation circuit
), and the second chromaticity signal separation circuit calculates the chromaticity signal (C
2) The adaptive luminance signal/chromaticity signal separation device according to claim 1, wherein the calculation for obtaining 2) is as follows. (4) A sample circuit that samples the color television signal (v(t)) at a predetermined period (Ts) synchronized with the phase of the color subcarrier, and a discrete sample sampled by this sample circuit. Color television signal (V(
(Ts); n is an integer), and the total delay time for delaying the signal in units of Ts is the color subcarrier period (Ts
c) The m-pattern color television signal v(nTs
), multiple signals (v(kT
s);
a first chromaticity signal separation circuit that separates the chromaticity signal of Ts), and a plurality of discrete color television signals (v(nTs)) after v(nOTs) delayed by the delay circuit; Input the signal (v(kTs); ≧n□),
a second chromaticity signal separation circuit that separates a chromaticity signal of v(n□Ts) by multiplying the signals by predetermined weighting coefficients and adding them; and the discrete color delayed by the delay circuit. Of the television signal (v(nTs)), from v(n□Ts−Tsc), v(nors+Tsc
) up to multiple signals (v(kTs) : n(1+Ts
c/'I's≧:? n□-Tsc/rs),
The third step separates the chromaticity signal of v(n□Ts) by multiplying the cough signals by predetermined weighting coefficients and adding them together.
of the chromaticity signal separation circuit and the discrete color television signal delayed by the delay circuit, v(ngTs) of the y signal (v(nT@)). Input v(nOTs+Tsc), v(noTs-Tsc), and set the predetermined constant A and 1v(n□'I'5)-v(nO
Ts-Tsc)l and lv(ngTs)-v(n□Ts-
pTsc) A determination circuit that outputs a predetermined determination signal indicating a magnitude relationship with I, and a chromaticity signal (CI) separated by the first chromaticity signal separation circuit. The separated nine color change signal (Cm)% chromaticity signal (C3) separated by υ by the third chromaticity signal separation circuit and the nine front distribution judgment signal output from the judgment circuit are input, and the judgment signal A selection circuit that outputs C1 when the content is , outputs C2 when , and outputs C3 when , and a chromaticity signal (Co) output from this selection circuit. , a subtraction circuit for obtaining L-eye luminance No. 1 by subtracting from the discrete color television')g signal having the same delay time as the signal; ! Luminance signal chromaticity signal separation device. (5) The first color is the chromaticity signal (C1) of the signal separation circuit.
), the rounding operation to obtain the chromaticity signal (C
5. The adaptive luminance signal/chromaticity signal separation apparatus according to claim 4, wherein the rounding operation to obtain 2) is as follows. C6) The chromaticity signal (CI) of the first chromaticity signal separation circuit
) to obtain the chromaticity signal (C
2) The adaptive luminance signal/chromaticity signal separation device according to claim 4, wherein the calculation for obtaining the following is performed. 17) The adaptive luminance signal/chromaticity signal separation device according to claim 4, wherein the third chromaticity signal separation circuit performs an operation for obtaining the chromaticity signal C3.