KR19990002920A - A luminance and color signal separation method and a luminance and color signal separation circuit for performing the same - Google Patents

Abstract

A luminance and color signal separation circuit for separating a luminance signal and a color signal from a composite video signal is disclosed. The frame comb filter adaptively filters the composite video signal input through the input terminal in the time axis direction to separate the first luminance signal and the first color signal, respectively. The line comb filter adaptively filters the composite video signal input through the input terminal in the horizontal axis direction to separate the second luminance signal and the second color signal, respectively. The two-line comb filter adaptively filters the second luminance signal separated by the line comb filter in the horizontal axis direction to detect the third luminance signal. The motion detector generates a detection signal A based on the motion of the composite video signal input through the input terminal, and the 3.58 MHz detector detects the 3.58 MHz frequency component value (B) of the second color signal separated by the line comb filter. ). The controller then generates a control signal in accordance with the motion detection signal A and the 3.58 MHz frequency component value B of the second color signal detected by the motion sensor. The output unit selectively outputs the first, second and third luminance signals and the first and second color signals in response to the detection signal generated by the controller. When the luminance and color signals are separated, the separation of the luminance signal and the color signal is increased according to the motion detection signal of the composite video signal and the 3.58 MHz frequency component value of the color signal.

Description

A luminance and color signal separation method and a luminance and color signal separation circuit for performing the same

The present invention relates to a luminance and color signal separation method of a television receiver and a luminance and color signal separation circuit for performing the same. More specifically, the present invention separates the luminance signal and the color signal according to the motion detection signal of the composite image signal and the 3.58 MHz frequency component value of the color signal when separating the luminance and color signals from the input composite image signal. A luminance and color signal separation method for controlling the output of the color signal and a luminance and color signal separation circuit for performing the same.

In general, the human eye is known that color information such as hue and saturation does not need to be as detailed as the information necessary for luminance in the image quality and image of the same sharpness. Therefore, the largest frequency band is allocated to the luminance signal in the frequency band of the television. On the other hand, for hue and saturation that do not correspond to the amount of change in luminance, the human eye should have 1/10 to 1/3 of the resolution required for brightness.

Color signals modulated as color subcarriers due to the above properties are put in a band much narrower than the luminance signal band. For example, in the NTSC system, an I signal component of a color signal modulated as a color subcarrier uses a 1.3 MHz band, and a Q signal component uses a 0.5 MHz band. Providing a wider band for the I signal component compared to the Q signal component of the color signal is because the I signal is better for color resolution.

Since the frequency of the color carrier is 3.58 MHz, the modulated color signal is interleaved on the high frequency sideband of the luminance signal to generate a composite image signal. The comb filter method is used to minimize the attenuation of the luminance signal and the interference by the luminance signal of the color signal when the luminance signal and the color signal interleaved with the luminance signal are separated from the composite image signal.

FIG. 1 is a circuit diagram showing the configuration of a conventional comb filter 10. An input terminal 11, a line delay unit 12, a first subtractor 13, a 1/2 amplifier 14, and a band pass filter (Band Pass Filter; BPF) 15, and a second subtractor 16. Referring to the operation of the comb filter 10, when a composite video signal is input to the line delay unit 12 through an input terminal 11, the line delay unit 12 outputs the input composite image signal to a television screen. Delays during the scan time of one horizontal line are output to the subtractor 13. The first subtractor 13 subtracts the line delay signal from the line delay unit 12 from the current composite video signal input through the input terminal 11, namely, a difference signal in which luminance signal components are mutually attenuated. , The color signal is output to the 1/2 amplifier 14. Then, the half amplifier 14 amplifies the color signal output from the subtractor 13 by half and outputs it to the band pass filter 15. The band pass filter 15 filters the 1/2 amplified color signal from the 1/2 amplifier 14 and provides it to the second subtractor 16 and outputs it to the outside. The second subtractor 16 subtracts the filtered 1/2 amplified color signal from the band pass filter 15 from the current composite video signal input through the input terminal 11 to subtract the luminance signal Y. And output the generated luminance signal Y to the outside.

FIG. 2 is a block diagram showing an example of a conventional luminance and color signal separation circuit using the comb filter of FIG. In FIG. 2, the luminance and color separation circuit 100 includes a 3 MHz low pass filter (LPF) 110, a subtractor 120, a comb filter 130, and an adder 140. The low pass filter 110 passes the composite video signal 102 input from the input terminal 101 to provide the subtractor 120 with the low pass composite video signal 112. The composite video signal passing through the low pass filter 110 is a frequency signal of only a luminance component.

The subtractor 120 subtracts the frequency signal 112 of only the luminance component within a frequency range of 3 MHz or less input from the low pass filter 110 from the composite image signal 102 input from the input terminal 101. A complex video signal 122 having a luminance and a color signal interleaved with each other is generated and provided to the comb filter 130. The comb filter 130 comb-filters the input interleaved composite video signal of 3 MHz or more to generate a color signal 134 and C and a luminance signal 132 of 3 MHz or more to generate the generated color signals 134 and C. And outputs the luminance signal 132 of 3 MHz or higher to the adder 140. Then, the adder 140 adds the luminance signal 112 from the low pass filter 110 and the luminance signal 132 from the comb filter 130 to output the luminance signal Y to the outside.

That is, in the comb filter 10, the color signal components of two consecutive horizontal scanning lines have a phase difference of 180 °. Accordingly, the comb filter 10 removes the luminance signal component from the composite image signal by calculating a signal difference between the composite image signal inputted over a horizontal line time and the currently input composite image signal, thereby removing only the color signal component. Get However, in the comb filter 10, as the image moves horizontally and vertically, the correlation between lines is weakened, and a hanging dot phenomenon occurs on the screen, and the correlated adaptive color signal is a band pass filter. When passing through 15, a color signal is mixed with the luminance signal, thereby causing a dot crawl phenomenon.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an improved luminance and brightness to prevent a color signal from being incorporated into a luminance signal when separating the luminance and color signals from a composite video signal. Provides a method of color signal separation.

It is a second object of the present invention to provide a luminance and color separation circuit which is particularly suitable for performing the above-described luminance and color signal separation method.

1 is a circuit diagram showing the configuration of a conventional comb filter.

2 is a block diagram illustrating an example of a conventional luminance and color signal separation circuit.

3 is a block diagram illustrating a luminance and color signal separation circuit according to an exemplary embodiment of the present invention.

FIG. 4 is a flowchart for explaining an operation principle of the luminance and color signal separation circuit shown in FIG. 3.

5A and 5B show spectra of respective parts of FIG. 3.

Explanation of symbols for the main parts of the drawings

13: 3 MHz low pass filter 15, 26, 130, 250, 280: subtractor

Adder: 19, 25, 120, 240, 270, 330, 340, 350, 360

17: comb filter 23, 230, 260: 1H delay

110: 2H delayer 410, 420: 3.58 MHz detector

510: controller 610, 620: switch

In order to realize the first object of the present invention described above, the present invention provides a method for separating the first luminance signal and the first color signal by adaptively filtering the composite video signal input through the input terminal in the time axis direction. Step for; (b) adaptively filtering the composite video signal input through the input terminal in a horizontal axis direction to separate the second luminance signal and the second color signal; (c) detecting a third luminance signal by adaptively filtering the second luminance signal separated by the step (b) in a horizontal axis direction; (d) generating a detection signal A based on the motion of the composite video signal input through the input terminal; (e) detecting a 3.58 MHz frequency component value (B) of the second color signal separated by step (b); (f) generating a control signal according to the motion detection signal A and the 3.58 MHz frequency component value B of the second color signal detected by step (d); And (g) selectively outputting the first, second and third luminance signals and the first and second color signals in response to the sensing signal generated by step (f). Provides a signal separation method.

In order to achieve the above-described second object of the present invention, the present invention provides a frame for separating the first luminance signal and the first color signal by adaptively filtering the composite video signal input through the input terminal in the time axis direction. Comb filter; A line comb filter for adaptively filtering the composite video signal input through the input terminal in a horizontal axis direction to separate the second luminance signal and the second color signal, respectively; A two-line comb filter for adaptively filtering the second luminance signal separated by the line comb filter in a horizontal axis direction to detect a third luminance signal; A motion detector for generating a detection signal A based on the motion of the composite video signal input through the input terminal; A 3.58 MHz detector for detecting a 3.58 MHz frequency component value (B) of a second color signal separated by said line comb filter; A controller for generating a control signal according to the motion detection signal A and the 3.58 MHz frequency component value B of the second color signal detected by the motion detector; And an output unit for selectively outputting the first, second and third luminance signals and the first and second color signals in response to the sensing signal generated by the controller. .

According to the present invention, the composite video signal input through the input terminal is separated into a first luminance signal and a first color signal, and separated into a second luminance signal and a second color signal. A third luminance signal is detected from the separated second luminance signal. A motion is detected from the composite video signal input through the input terminal, and a 3.58 MHz frequency component is detected from the separated second color signal. A control signal is generated in response to the motion detection signal of the detected composite video signal and the 3.58 MHz frequency component value of the detected second color signal. The separated first luminance signal and the first signal, the second luminance signal and the second color signal, and the third luminance signal are output according to the control signal.

Therefore, when the luminance and color signals are separated from the input composite image signal, the luminance and color signals are separated according to the detected motion detection signal and the 3.58 MHz frequency component by detecting the 3.58 MHz frequency component of the motion and color signals of the composite image signal. By eliminating crosstalk between the luminance signal and the color signal, the separation of the luminance and color signals of the composite video signal is increased.

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

3 is a block diagram illustrating a luminance and color signal separation circuit according to an exemplary embodiment of the present invention. The luminance and color signal separation circuit 800 includes a frame comb filter 100, a line comb filter 200, a two-line comb filter 300, a motion detector 400, a 3.58 MHz detector 500, a controller 600, And an output unit 700.

The composite image signal 102 input from the input terminal 101 is input to the frame comb filter 100, the line comb filter 200, and the motion detector 400. The composite image signal 102 input to the frame comb filter 100 is adaptively filtered in the time axis direction by the frame comb filter 100 to thereby obtain a first luminance signal Y _f and a first color signal C _f. ) And output the generated first luminance signal Y _f and the first color signal C _f to the output unit 700.

The composite image signal 102 input to the line comb filter 200 is adaptively filtered in the horizontal axis direction by the line comb filter 200 to generate a second luminance signal Y _l and a second color signal C _l . Is generated, and the generated second luminance signal Y _l is output to the two-line comb filter 300 and the output unit 700, and the second color signal C _l is output to the output unit 700. Output to

The second luminance signal Y _l input to the two-line comb filter 300 is adaptively filtered in the horizontal axis direction by the two-line comb filter 300 to detect and detect a third luminance signal Y _2l . The third luminance signal Y _2l to the output unit 700.

The motion detector 400 detects the motion of the television image based on the input composite video signal 102 to generate a detection signal A, and provides the generated detection signal A to the controller 600. do.

The motion detector 400 detects a motion from the input composite image signal 102, and generates a detection signal A of logic high when the detected motion is greater than or equal to a predetermined reference size. When it is detected to be less than a predetermined reference size, a sense signal A of a logic row is generated.

The 3.58 MHz detector 500 receives the second color signal C _l output from the line comb filter 200, and controls the 3.58 MHz frequency component value B of the second color signal C _l to the controller. Provided at 600.

The controller 600 outputs a control signal generated by comparing the motion detection signal A from the motion detector 400 with the 3.58 MHz frequency component value B from the 3.58 MHz detector 500. )

The output unit 700 includes a first switch SW1 and 710 and a second switch SW2 and 720.

The first switches SW1 and 710 are input through the first, second, and third input terminals T1, T2, and T3 in response to a control signal output from the controller 600. The luminance signal output from the filter 100, the line comb filter 200, and the two line comb filter 300 is selected and output to the outside through the luminance signal output terminal Y.

The second switch (SW2, 720) is the frame comb filter 100 is input through the first and second input terminals (T4, T5) in response to a control signal output from the controller 600, And outputs the color signal output from the line comb filter 200 to the outside through the color signal output terminal C.

4 is a flowchart for explaining the operation principle of the luminance and color signal separation circuit shown in FIG. Next, the operation principle of the luminance and color signal separation circuit having the above-described configuration will be described with reference to the flowchart shown in FIG.

The composite image signal 102 input to the frame comb filter 100 is adaptively filtered in a time axis direction to separate a first luminance signal Y _f and a first color signal C _f from The first luminance signal Y _f and the first color signal C _f are output to the first switch 710 of the output unit 700 (step S1).

The composite image signal 102 input to the line comb filter 200 is adaptively filtered in a horizontal axis direction to separate a second luminance signal Y _l and a second color signal C _l , and the separated second signal. The luminance signal Y ₁ is output to the two-line comb filter 300, and the second color signal C ₁ is output to the first switch 710 of the output unit 700 (step S2).

The 2-line comb filter and the second luminance signal to be input to the (300) (Y _l) for detecting a third luminance signal (Y _2l) by adaptive filtering in the horizontal direction, and said third luminance signal (Y _2l) is detected Is output to the first switch 710 of the output unit 700 (step S3).

The composite image signal 102 input to the motion detector 400 detects the motion of the television image to generate a detection signal A, and provides the generated detection signal A to the controller 600 ( Step S4). The motion detector 400 detects a motion from the input composite image signal 102, and generates a detection signal A of logic high when the detected motion is greater than or equal to a predetermined reference size. When it is detected to be less than a predetermined reference size, a sense signal A of a logic row is generated.

By detecting the line comb filter 200, a second color signal of the 3.58MHz detector 500 receives the input (C _l) from the output 3.58MHz frequency component of the second color signal (C _l), the value (B), The detection value is provided to the controller 600 (step S5).

The controller 600 comparing the motion detection signal A from the motion detector 400 with the 3.58 MHz frequency component value B from the 3.58 MHz detector 500 determines a control signal to determine a control signal. The output unit 700 outputs to the first switches SW1 and 710 and the second switches SW2 and 720 (step S6).

The first switches SW1 and 710 are input through the first, second, and third input terminals T1, T2, and T3 in response to a control signal output from the controller 600. The luminance signal output from the filter 100, the line comb filter 200, and the two line comb filter 300 is selected and output to the outside through the luminance signal output terminal Y (step S7).

The second switch (SW2, 720) is the frame comb filter 100 is input through the first and second input terminals (T4, T5) in response to a control signal output from the controller 600, And output the color signal output from the line comb filter 200 to the outside via the color signal output terminal C (step S8).

5A and 5B illustrate spectra of output portions of the line comb filter 200 and the two line comb filter 300 of FIG. 3.

5A and 5B, the motion detection signal of the composite image signal and the 3.58MHz frequency component of the second color signal C _l are detected by detecting the motion detection signal of the composite image signal. And whether or not the luminance signal and the color signal are passed according to the strength of the 3.58 MHz frequency component of the second color signal C _l .

5A and 5B, the operation principle of the output unit 700 in the luminance and color signal separation circuit of the present invention will be described in connection with the first switch 710 and the second switch 720. Table 1 shows.

How the switch works A B First switch (SW1) Second switch (SW2) 0 × First input terminal T1 First input terminal T4 One 0 Second input terminal T2 Second input terminal T5 One One Third input terminal T3 Second input terminal T5

By the above configuration, the motion detector 400 detects motion from the input composite image signal, and if there is no motion, the first luminance signal Y _f and the first color signal ( _f ) output from the frame comb filter 100. To output C _f ), the first switch 710 is connected to a first input terminal T1 and the second switch is connected to a first input terminal T4.

When the motion is detected from the motion detector 400, a second luminance signal Y _l and a second color signal C _l output from the line comb filter 200 are used. 5A illustrates a frequency spectrum of the second luminance signal Y ₁ output from the line comb filter 200.

When motion is detected, the luminance signal output is determined according to the 3.58 MHz frequency component value of the second color signal C ₁ . When the 3.58 MHz carrier frequency component value detected from the second color signal C _l is not detected, in order to output the second luminance signal Y _l and the second color signal C _l , the first switch ( 710 is connected to a second input terminal T2 and the second switch is connected to a second input terminal T5. When the 3.58 MHz carrier frequency component value detected from the second color signal C _l is detected, the first switch 710 to output the third luminance signal Y _2l and the second color signal C _l . ) Is connected to the third input terminal T3 and the second switch is connected to the second input terminal T5. 5B illustrates the frequency spectrum of the third luminance signal Y _2l output from the two-line comb filter 300.

Accordingly, according to the above configuration, the 3.58 MHz frequency component is detected from the motion detection signal and the second color signal C _l detected from the composite image signal, and the luminance signal and the luminance signal are determined according to the detected motion detection signal and the 3.58 MHz frequency component value. By selectively passing the color signal to prevent the color signal from being incorporated into the luminance signal, crosstalk is reduced when the luminance and color signals are separated from the composite video signal, thereby improving the separation between the luminance signal and the color signal.

As described above, the present invention reduces the crosstalk between the luminance signal and the color signal generated when the luminance signal and the color signal are separated from the composite video signal, thereby separating the luminance signal and the color signal into the luminance and color signals. The method and separation circuit can be realized.

Although this invention was demonstrated concretely by the said Example, this invention is not restrict | limited by this, A deformation | transformation and improvement are possible within the range of common knowledge of a person skilled in the art.

Claims (4)

(a) adaptively filtering the composite video signal input through the input terminal in the time axis direction to separate the first luminance signal Y _f and the first color signal C _f ; (b) adaptively filtering the composite video signal input through the input terminal in a horizontal axis direction to separate the second luminance signal Y _l and the second color signal C _l , respectively; (c) adaptively filtering the second luminance signal separated by step (b) in the horizontal axis direction to detect a third luminance signal (Y _2l ); (d) generating a detection signal A based on the motion of the composite video signal input through the input terminal; (e) detecting a 3.58 MHz frequency component value (B) of the second color signal (C _l ) separated by step (b); (f) a control signal according to the 3.58 MHz frequency component value B of the motion detection signal A detected by step (d) and the second color signal C _l separated by step (e). Generating; And (g) a luminance and color signal configured to selectively output the first, second and third luminance signals and the first and second color signals in response to the sensing signal generated by step (f) Separation method. The method of claim 1, wherein step (g) (g-1) outputting a first luminance signal (Y _f ) output by step (a) when the motion is not detected by step (d); (g-2) The second luminance signal Y _l when the motion is detected by step (d) and a 3.58 MHz frequency component is not detected from the second color signal C _l by step (e). Outputting; (g-3) When the motion is detected by the step (d) and the 3.58 MHz frequency component is detected from the second color signal C _l by the step (e), the third luminance signal Y _2l is applied. A luminance signal output step comprising an output; (g-4) outputting a first color signal (C _f ) output by step (a) when the motion is not detected by step (d); And and (g-5) a color signal output step comprising outputting a second color signal (C _l ) when motion is detected by step (d). A frame comb filter 100 for adaptively filtering the composite video signal input through the input terminal in a time axis direction to separate the first luminance signal and the first color signal, respectively; A line comb filter 200 for adaptively filtering the composite video signal input through the input terminal in a horizontal axis direction to separate the second luminance signal and the second color signal; A two-line comb filter 300 for adaptively filtering the second luminance signal separated by the line comb filter 200 in a horizontal axis direction to detect a third luminance signal; A motion detector 400 for generating a detection signal A based on the motion of the composite video signal input through the input terminal; A 3.58 MHz detector 500 for detecting a 3.58 MHz frequency component value B of the second color signal separated by the line comb filter 200; A controller (600) for generating a control signal in accordance with the motion detection signal (A) detected by the motion detector and the 3.58 MHz frequency component value (B) of the second color signal; And And an output unit 700 for selectively outputting the first, second and third luminance signals, and the first and second color signals in response to the sensing signal generated by the controller. And color signal separation circuit. The method of claim 3, wherein the output unit 700 is A first input terminal (T1) for outputting a first luminance signal (Y _f ) from the frame comb filter (100) when motion is not detected by the motion detector (400); When the motion is detected by the motion detector 400 and the 3.58 MHz frequency component is not detected from the second color signal C _l by the 3.58 MHz detector 500, the second luminance signal Y _l is output. A second input terminal T2; And when a motion is detected by the motion detector 400 and a 3.58 MHz frequency component is detected from the second color signal C _l by the 3.58 MHz detector 500, a third luminance signal Y _2l is output. First switches (SW1, 710) including a third input terminal (T3) for the purpose of; And A first input terminal (T4) for outputting a first color signal (C _f ) output by the frame comb filter (100) when motion is not detected by the motion detector (400); And a second switch (SW2, 720) including a second input terminal (T5) for outputting a second color signal (C _l ) when the motion is detected by the motion detector (400). Luminance and color signal separation circuit.