KR930008183B1 - Y/c separate system - Google Patents

Abstract

The luminance/chrominance component separator includes a luminance component separator for outputting a high or low potential according to the luminance difference between the present line and previous line, a chrominance component separator for timing-controlling and outputting a chrominance component, a motion-adapted comb filter for outputting a chrominance component excluding a low-frequency luminance component, a luminance detecting signal generator for outputting a signal for detection of luminance component by canceling the luminance component left in the output signal of the motion-adapted comb filter, a luminance component detector for outputting a luminance signal containing or free of a chrominance component, a control signal generator for a high-potential control signal, and a switch for selecting the output of the chrominance component separator or the output of the motion-adapted comb filter as a final chrominance signal, thereby facilitating the separation of luminance and chrominance signals with hardware and reducing the cost.

Description

Luminance / Color Component Separator

1 is a block diagram of a general luminance / chromatic component separation device.

2 is a block diagram of a luminance / chromatic component separation device of the present invention.

3 (a) to 3 (j) are waveform diagrams of respective parts of FIG.

4 is a logical operation table of the oragate OR1 in the control signal generator 600. FIG.

5 is an embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

11: Low pass filter 12, 31, 66: 1 line delay

13, 32, 34: subtractor 14, 61, 63: absolute value calculation unit

15, 62, 64: comparison unit 21, 54: band filter

22, 51, 53: delay matching unit 33: high pass filter

41: dress hold part 42: limiter

43: adder 52: chroma reduction unit

56: band stop filter 55, 700: switching unit

65 latch portion 100 luminance component separation unit

200: chromatic component separation unit 300: motion adaptive comb filter

400: luminance component detection signal generator 500: luminance component detection unit

600: control signal generator

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for separating luminance signals and chromaticity signals in a color TV receiver, and in particular, luminance / chromatic components for separating luminance / chromatic components according to horizontal and vertical transition states using an adaptive comb filter. It relates to a component separation device.

In the NTSC broadcasting system, two color signals are multiplexed with color subcarriers for intercompression of the transmission frequency band and black and white TV, and interlaced between the luminance signals so that color and luminance signals exist in the same frequency band. The luminance signal exists at intervals of a predetermined frequency (15.7 KHz), and the color signal exists at an intermediate frequency of the predetermined frequency.

Therefore, in the separation of NTSC video signals into color signals and luminance signals, cross-talk occurs due to no complete separation, which causes the screen to deteriorate, which is generally used to prevent such a phenomenon. The luminance / chromatic component separation device as shown in FIG. 1 is as follows.

As the composite video signal CV passes through the line comb filter 1 and the frame comb filter 2, the color signal components V (n) and (T (n)) are detected, and they are multipliers MP1, ( After multiplying by the motion factor MF respectively input to the MP2) and output by the motion detection unit 3, the summation signal Co is added to each other by the adder 4 to output the sum signal Co. It is expressed as

Co (n) = K. V (n) + (1-K). T (n) ∵0 <K <1)

Here, the motion detector 3 controls the multiplication ratios K and 1-K of the multipliers MP1 and MP2 according to the color signal component T (n) applied thereto, and their values change linearly to stop. In the case of an image, since the K value approaches "0", the multiplication by the frame comb filter 2 is implemented. In the case of a moving screen, the K value approaches "1", so the multiplication is performed by the output of the line comb filter 1. Is implemented.

However, in the conventional apparatus, since the motion is detected using the frame memory, the hardware configuration is very complicated and the cost increases accordingly.

In order to solve the above problems, the present invention has been devised an apparatus capable of separating luminance / chromatic components according to horizontal and vertical transition states using an adaptive comb filter without using a frame memory. It demonstrates in detail by drawing.

FIG. 2 is a block diagram of the luminance / chromatic component separating apparatus of the present invention, as shown in FIG. 2, which detects a luminance component of a low frequency region from an NTSC composite video signal (CV) and compares it with a luminance component detected in a previous line. After obtaining the difference, the luminance component separation unit 100 outputs a low potential or a high potential according to its absolute value, and a chromaticity component separation unit which detects chromatic components from the composite image signal CV and then outputs the timing control. 200), a motion adaptive comb filter 300 for outputting a chromatic component from which luminance components of a low frequency region obtained by obtaining a difference between a current line component and a previous line component are output, and an output signal of the motion adaptive comb filter 300; The composite zero is removed by using the luminance component detection signal generator 400 for removing a luminance component remaining in the signal and outputting a signal for luminance component detection, and the output signal of the luminance component detection signal generator 400. A luminance component detection unit 500 which detects a luminance component from the signal CV and then outputs a luminance signal including a chroma component or a luminance signal not included according to the control of the control signal generator 600 described later; A high potential is output from the luminance component separation unit 100, or a part of color components is mixed into the luminance signal due to color change in the vertical direction, or a luminance component of 3.58 MHz is output from the next sampling point with chromatic components, or The control signal generator 600 outputs a high potential when there is no luminance component of 3.58 MHz in the line and there is a chroma component in the current line, and the high potential is output from the control signal generator 600. When the output of the chromatic component separation unit 200 is selected as the chroma signal (Cout), when the low potential is output from the control signal generator 600 to output the output of the motion adaptive comb filter (300) chroma signal ( With Cout) It was composed of a switching unit 700 for selecting.

On the other hand, (a) to (j) of FIG. 3 is a waveform diagram of each part of FIG. 3, and FIG. 4 is a logical operation table of the ORA gate OR1, and the operation and effects of the present invention will be described in detail. Is as follows.

When the NTSC composite video signal CV of the 3a diagram is applied to the low pass filter 11, a luminance signal of 3 MHz or less without chroma component is detected and output on the output side thereof, such as the 3e diagram, which is delayed by one line. If the output signal of the first line delay unit 12 is equal to 3f, the output signal of the current subtractor 13 is delayed by one line to the output signal of the low pass filter 11. The output signal of the machine 12 is subtracted to become the third g degree.

When the output signal of the subtractor 13 is calculated as an absolute value of the magnitude in the absolute value calculator 14 and then applied to the comparator 15 again, when the output signal of the subtractor 13 is larger than the preset threshold value, Since it is considered that there is a high frequency component, a high potential is output to the output side of the comparison section 15 as shown in FIG. 3 (difference).

On the other hand, the band filter 21 detects a chromaticity component such as a 3d degree from the composite image signal CV, and the timing is adjusted while being output through the delay matching unit 22.

In addition, since the one-line delay unit 31 delays and outputs the composite video signal CV by one line, the subtractor 32 outputs the composite video signal CV of the current line from the composite video signal CV of the previous line delayed by one line. And subtracts the low-frequency luminance signal from the composite video signal CV of the current line and outputs the subtractor 34 to the high pass filter. The output signal of 33) is extracted and a chromaticity signal adapted to the movement is output as shown in FIG.

On the other hand, since the chroma signal output from the subtractor 34 is output through the threshold hold unit 41, the limiter 42, and the adder 43, the luminance component remaining in the chroma signal is removed, because these signals This is because the chromaticity component exceeding the threshold hold value is not affected by the functions of the threshold hold part 41, the limiter 42, and the adder 43.

The delay matcher 51 controls timing and outputs the currently applied composite video signal CV, and the chroma subtracter 52 adds the timing-controlled composite video signal CV to the delay matcher 51. By subtracting the chroma component of (43), a luminance signal equal to the third c degree is output, which is again time-controlled by the delay matching unit 53 and then performs a conservative function with each other. Is provided.

As a result, a luminance signal, such as a 3h degree, from which the chromaticity component is removed is output from the band blocking filter 56. When a chromaticity signal is detected, such as a 3i degree, on the band filter 54, it is applied to the switching unit 55. Meanwhile, the luminance information and the chroma subcarriers located around the subcarrier (3.58 MHz) are output to the other side of the band filter 54 so that the absolute value of the magnitude is calculated by the absolute value calculating unit 63, and then the comparator 64 again. It is applied to and compared with the preset threshold hold value.

In addition, the chroma signal output from the subtractor 34 is also applied to the comparison unit 62 after the absolute value of the magnitude is calculated in the absolute value calculating unit 61 as described above, and compared with the preset threshold hold value. And accordingly output as a high potential or potential signal.

In general, due to the low level output from the ORA gate OR1, the switching unit 700 selects and outputs the same chromaticity signal output from the subtractor 34 as the final chromaticity signal Cout, and then switches. Since the unit 55 is also opened with the adder 57, the adder 57 outputs the luminance signal which does not include the chroma signal as the third luminance output from the band stop filter 56 as the final luminance signal Yout. Done.

However, if at least one of the output signals of the comparator 15 and the AND gates AD1, AD2, and AD4 is outputted, at this time, artifacts are caused by the property between the chroma signal output and the luminance component of 3.58 MHz. In case of occurrence, this means that the predetermined threshold hold value is exceeded. In this case, since the switching unit 700 is switched by the high potential output of the OR gate OR1, the output of the delay matching unit 22 such as the 3d degree is output. Is outputted as the final chroma signal Cout, and at this time, the switching unit 55 is also switched, so that the adder 57 adds the third luminance and the same chroma signal to the final luminance signal Yout. When the OA gate OR1 outputs a high potential as shown in the 3j diagram, it is as follows.

First, when the luminance component of the current line detected by the low pass filter 11 is greater than the threshold value, second, a portion of the color component is mixed with the luminance signal by the color change in the vertical direction, and the luminance component (subcarrier) of 3.58 MHz is added. ) And when the chromatic component phase is the same, that is, when the output of the AND gate AD1 is high potential, and third, when a luminance component of 3.58 MHz appears at the next sampling point with the chromatic component, that is, the output of the AND gate AD2. At this high potential, fourth, when there is no luminance component of 3.58 MHz in the previous line and there is a chromatic component, and the luminance component of 3.58 MHz appears in the current line, that is, when the high potential is output to the AND gate AD4, If one or more of the conditions are satisfied, a high potential is output to the output terminal of the OR gate OR1, which is shown in FIG. 4, where X is the output value A of the comparator 15, and Y Is the output of the comparison unit 64 As a result, when the value detected by the band filter 54 exceeds the threshold hold value, it is output at the same high potential as the third j degree, and when it is not exceeded, the low potential state is maintained, and Z is an output value of the comparator 62. As a result, when the level of the absolute value output from the subtractor 34 exceeds the threshold value, it is output as the 3b degree, and when it is not exceeded, it is output as the 3d degree.

On the other hand, Figure 5 is an exemplary embodiment of the present invention as shown in this it is possible to obtain the output of the chroma signal (Cout1) by continuously combining the motion adaptive comb filter 300 of FIG.

As described in detail above, the present invention allows the separation of luminance and luminance components according to horizontal and vertical transition states using an adaptive comb filter without using a frame memory. In addition to being able to reduce costs.

Claims (4)

A luminance component separation unit 100 for outputting a high potential or a low potential according to the luminance component difference between the current line and the previous line, a chromaticity component separation unit 200 for controlling the timing of the detected chromaticity component and outputting the current line; After obtaining the difference between the previous line components, the adaptive adaptive comb filter 300 for outputting the chromatic component from which the luminance component is removed in the low frequency region and the luminance component remaining in the output signal of the adaptive adaptive comb filter 300 are removed. After detecting the luminance component from the luminance component detection signal generator 400 for outputting a signal necessary for luminance component detection, the composite video signal CV and the output signal of the luminance component detection signal generator 400, According to the control signal, the luminance component detector 500 outputs the luminance signal including the chroma component or the luminance signal without the luminance signal, and the high potential is output from the luminance component separator 100, or a part of the chromatic components is the luminance. A control signal that outputs a high-potential control signal when a luminance component appears at the next sampling point with chromatic components, chromatic components, or there are no luminance components and chroma components on the previous line but the luminance component appears on the current line. The output signal of the chromatic component separation unit 200 or the output signal of the adaptive comb filter 300 according to the output signal of the generator 600 and the control signal generator 600 is the final chroma signal Cout. Luminance / chromatic component separation device, characterized in that consisting of a switching unit for outputting by selecting. 2. The apparatus of claim 1, further comprising: a one-line delayer (31) for delaying the composite video signal (CV) by one line and a subtractor (32) for subtracting the current line signal from the output signal of the one-line delayer (31). And a high pass filter 33 which removes a low frequency luminance signal from the composite video signal CV of the current line, and a subtractive output signal of the high pass filter 33 from an output signal of the subtractor 32 to generate a chromaticity signal. A luminance / chromatic component separation device comprising a motion-adaptive comb filter 300 as a subtractor 34 for outputting. The signal generator of claim 1, further comprising a delay matching unit (51) for timing-controlling and outputting the composite video signal (CV) of the current line, and a signal generating unit (400) for detecting the luminance component in the delay matching unit (51) and an output signal. A band filter for detecting chromaticity components by band-passing the chroma subtractor 52 for subtracting the output signal of the signal, the delay matcher 53 for timing control again, and the output signal of the delay matcher 53. 54, a band blocking filter 56 which suppresses a band pass among the output signals of the delay matching unit 53, and outputs a luminance component, and the band blocking filter under control of the control signal generator 600; The luminance component detection unit 500 is configured by a switching unit 55 which outputs the output signal of the output signal 56 separately or outputs the luminance signal Yout obtained by adding the output signal of the band pass filter 54. Luminance / Color Component Separator. The absolute value calculating part 61 which calculates the absolute value of the output chromaticity component of the said subtractor 34, and the magnitude | size of the output signal of the absolute value calculating part 62 are compared with a threshold hold value. Comparator 62 for outputting a signal corresponding thereto, an absolute value calculator 63 for calculating an absolute value for the output signal of the band pass filter 54, and an output signal of the absolute value calculator 63 A comparison unit 62 that compares the magnitude of the signal with a threshold hold value and outputs a corresponding signal, and an AND gate that logically combines the output signals of the comparison units 62 and 64 as an input of the OR gate OR1. A luminance / chromatic component separation device comprising a control signal generator 600 configured as (AD1-AD4).

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