KR930000982B1 - Movement detecting circuit - Google Patents

Abstract

The movement detection circuit for improving the picture quality and preventing the misoperation comprises: a section (10) separating the chrominance signal obtained by filtering the inputted signal through the horizontal bandpass filter, the vertical bandpass filter, the time-axis bandpass filter and the luminance signal obtained from an adder; a detection section (20) detecting the chrominance signal operated between the frames; a section (30) detecting the operation of luminance signal; a processing section (40) converting the detected chrominance/ luminance signal into the absolute value; a circuit generating the maximum value among the values outputted from the processing section (40).

Description

Motion Detection Circuit with Isolation Point Removal in Television Receivers

1 is a filter characteristic diagram on a horizontal and vertical plane.

2 is a filter characteristic diagram on a vertical, time plane.

3 is a 3D sampling structure diagram of a TV signal.

4 is a circuit diagram according to the present invention.

5 is a level conversion characteristic diagram according to the present invention.

6 is an isolated point removal characteristic of a motion signal according to the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image quality improvement circuit in a television receiver. In particular, the present invention relates to Y / C separation and scanning line interpolation for image quality improvement in IDTV, EDTV, HDTV, etc. The present invention relates to a motion detection circuit with isolation point removal added to a television receiver.

The current NTSC method performs interlaced scanning. When interlaced scanning has the effect of reducing the bandwidth of the transmitted data, the scanline structure shown in the line flicker or flat moving image appears. In order to effectively remove or reduce this, the correlation of adjacent images is measured, and luminance / chromatic separation (hereinafter referred to as `` Y / C separation '') is performed in a large correlation direction. Will be handled adaptively. As a result, the motion signal must be obtained more accurately to obtain more accurate image data.

The conventional method of detecting the motion signal is obtained by obtaining a difference between one frame or two frames when a composite video signal is input. However, a significant side effect occurs when the difference is obtained without any processing of the video signal. First, when a difference of one frame is obtained without processing, as shown in FIG. 3, the phase of the chromaticity (C) signal is inverted by 180 degrees for each frame. Subtracting the point B from the point A as shown in FIG. 3 detects the frame difference signal with respect to the luminance (Y) signal, but for the chromaticity (C) signal, the frame difference value should be zero in the still image. Due to the inversion, a motion signal of twice the chromaticity (C) signal is detected, which is incorrectly detected as having a motion.

To avoid this, a low-pass filter is used to obtain a frame difference using only the luminance (Y) signal distributed in the low range. In this case, detection of the high-frequency luminance (Y) signal and chromaticity (C) signal is impossible. . Looking at the motion detection of the next two frame difference, there is a problem that the accurate movement is detected more accurately than the one frame difference for the motion signal with a fast motion on the vertical axis.

Accordingly, an object of the present invention is to provide a circuit that can reduce the error of motion detection by eliminating the isolated point because the motion is detected by the car when there is an isolated point when the motion signal is detected.

An object of the present invention for performing the above object is a means for inputting a composite video signal to the horizontal, vertical, time-base band filter to separate the luminance (Y) and chroma (C), the separated C signal is the operation between the frame It is inputted into the frame memory for detection and delayed by one frame, and this delayed signal is inputted to the multiplier to invert the phase to 180 ° and the signal is subtracted by the non-delayed signal and the subtractor to operate between the frames of the chromaticity (C) signal. Means for detecting and a luminance (Y) signal obtained by subtracting a chromaticity (C) component from the original signal (initial signal) by a subtractor is input to a frame memory, delayed by one frame, and input to the delayed signal and the frame memory. Means for detecting the inter-frame operation of the luminance (Y) signal by subtracting the signal and the subtractor, and the luminance (Y) signal and chroma (C) output as a result of the above result. Means for obtaining an absolute value by absolute value of the arc respectively, means for obtaining a maximum value by maximizing an absolute value of the output luminance (Y) signal and chromaticity (C) signal, and It is characterized in that it comprises a means for removing the isolated point by the median filter and converting the motion signal to a value of 0-1 with a level converter to obtain a final output.

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

1 is a filter characteristic diagram on horizontal and vertical planes, FIG. 2 is a filter characteristic diagram on vertical and temporal planes, and FIG. 3 is a three-dimensional sampling structure of a TV signal. 4 is a circuit diagram according to an embodiment of the present invention. An NTSC composite video signal is input through an input terminal 41 and filtered by a horizontal bandpass filter 100, a vertical bandpass filter 101, and a timebase bandpass filter 102. C) signal is obtained, the input signal of the input terminal 41 is delayed by the delay line 113, and the chromaticity (C) signal obtained by separating through the time-base bandpass filter 102 and the subtractor 108 is subtracted. The luminance / color separation unit 10 that separates the luminance Y signal, and the color signal output from the first luminance / color separation unit 10 in the frame memory 103 for inter-frame motion detection. Delay the unit by one frame and then invert 180 degrees in the interpolator 104 and subtract the color subtractor 105 from the color C signal obtained by the luminance / color separation unit 10. Chroma frame signal motion detection unit 20 for detecting inter-frame motion And a luminance Y signal obtained by the subtractor 108 of the luminance / color separation unit 10 is stored in the frame memory 109 and delayed in units of frames to subtract the signal before the one frame delay and the subtractor 110. And a chromaticity and luminance signal operation detection signal detected by the luminance signal operation detection unit 30, the chromaticity signal frame operation detection unit 20 and the luminance signal operation detection unit 30 to detect the operation of the luminance Y signal. An absolute value conversion processing unit 40 for converting the absolute value from the absolute value conversion circuits 106 and 111 to an absolute value, and a maximizing circuit 107 for generating a maximum value of the input by receiving the value output from the absolute value conversion circuit unit 40; The median filter 112 for removing the isolation point from the output of the maximizing circuit 107 and the motion signal from which the isolation point of the motion detection signal is removed from the median filter 112 are converted into a value of 0-1. Level converting levels to get output The bell converter 116 is configured.

FIG. 5 is an output characteristic diagram of the level converter 116 of FIG. 4, and FIG. 6 is an characteristic diagram of an output characteristic diagram of the median filter 112 of FIG.

Therefore, a specific embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6, first, the NTSC composite signal is input to the three-dimensional bandpass filter through the input terminal 41, that is, the horizontal, vertical, and time axis. The band pass filters 100, 101, and 102 are inputted. In the process, the horizontal band pass filter 100 is sampled at 4 fsc (fsc = 3.58 MHz) on the horizontal axis as shown in FIG. Impulse Response) filter is configured to have a passband of 0.5MHz, which is a band of chromaticity (C) signal, around the point where fsc is located on the horizontal axis.

Similarly, the bandpass filters 101 and 102 on the vertical and time axis are configured, and the characteristics of the filter appear in the form of a comb filter, so that the chromaticity (C) signal is precisely shown as shown in FIGS. The chromaticity (C) signal and the original signal are delayed by the delay line 113 by a predetermined delay, and the delayed signal is subtracted by the subtractor 108 to separate the luminance (Y) signal from the low range to the high range. Do it. That is, 100, 101, and 102 are horizontal, vertical, and time axis bandpass filters, respectively.

Looking at the motion detection through the frame difference with respect to the separated chroma signal (C), as described above, since the phase of the chroma signal (C) is inverted by 180 ° between frames, the signal passing through the frame memory 103 is a multiplier. 180 degrees out of phase by 104, the point B in FIG. 1 changes its phase from ψ + π to ψ so that the subtractor 105 reduces the pre-input signal from the frame memory 103 (BA). ), The difference in chromaticity (C) signal between the correct frames can be obtained. Similarly, the motion Y for the luminance Y signal can be detected by the frame memory 109 and the subtractor 110 for the luminance Y signal.

The luminance (Y) detection signal and the chromaticity (C) detection signal of the chroma signal frame motion detection unit 20 and the luminance signal operation detection unit 30 have positive and negative values, respectively, the first and second absolute circuits 106 and 111. To a negative value.

Only after such a process can be accurately compared by the maximizing circuit 107. For example, when the output of the subtractor 105 is 3 and the output of the subtractor 110 is -6, in reality, the momentum of the value of -6 rather than 3 is 3 by the first and second absolute circuits 106, respectively. If the absolute value is input to the maximizing circuit 107 in the form of 3 and -6, the momentum of 3 is output as more than -6. The signal output as described above is input to the median filter 112 to remove the isolation point. The median filter 112 has a characteristic of selecting a median value by comparing several sample values, as shown in FIG. Similarly, when a motion signal is detected, an isolation point may occur due to noise.

When the isolated point is present, there should be no exercise, but when a car is found, there is an exercise and an error occurs.

When the median filter 112 is used to remove this, the isolation point is removed as shown in FIG. 6, and when the B point is the isolated point at points A, B, and C as shown in FIG. Since the median of A, B, and C values is taken, the isolation point is removed as shown in the 6b. And at the rest of the points, it has a sharp low pass filter with almost no change in value. This filter has much sharper characteristics than a normal low pass filter.

The output signal is input to the level converter 116. The level converter 116 is a kind of comparator, and sets a threshold value to the input and outputs a value of 0-1 according to the size of the input.

In FIG. 5, a and b are threshold values, 0 when the input is smaller than a, 1 when larger than b, and 0-1 output that is proportional to the size of the input between a and b. It has the characteristic to 5 is a characteristic occurring at the level converter 116.

In this way, the final motion detection signal is output.

As described above, since the detection of the color and luminance signals is removed using the median filter for the generation of the isolated point due to the noise during the motion detection, there is an advantage of preventing malfunction of the motion detection and obtaining a high image quality.

Claims (1)

In the motion detection circuit of a television receiver, an NTSC composite video signal is input through an input terminal 41 and filtered by a horizontal band pass filter 100, a vertical band pass filter 101, and a time axis band pass filter 102. C) a signal is obtained, and the input signal of the input terminal 41 is delayed by the delay line 113 and subtracted from the chromaticity (C) signal and the subtractor 108 obtained by separating through the time-base bandpass filter 102. A luminance / color separator 10 for separating the luminance (Y) signal and a color signal output from the first luminance / color separator 10 are stored in the one-frame memory 103 to detect the inter-frame motion. Delay the unit by one frame and then invert it to 180 ° in the multiplier 104 to subtract the chroma signal C by subtracting the subtractor 105 from the color C signal obtained by the luminance / color separation unit 10. Chromaticity Signal Frame Motion Detecting Interframe Motion A luminance Y signal obtained by the detector 20 and the subtractor 108 of the luminance / color separation unit 10 is stored in the frame memory 109 and delayed in units of frames to delay the signal and the subtractor before the one frame delay ( The luminance signal operation detection unit 30 that detects the operation of the luminance signal by subtraction of 110, and the chromaticity and luminance signal operation detection signal detected by the chroma signal frame operation detection unit 20 and the luminance signal operation detection unit 30. Is the absolute value conversion processing unit 40 for converting the absolute value from the first and second absolute circuits 106 and 111 and the value output from the absolute value conversion circuit unit 40 to generate the maximum value of the input. The median filter 112 for removing the isolation point from the output of the circuit 107, the maximizing circuit 107, and the motion signal from which the isolation point of the motion detection signal is removed from the median filter 112 are 0-1. Level to convert to value to get final output The conversion level converter 116 according to the adapted television receiver, characterized by the isolated point removal of the additional motion detection circuit.

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