JPH04347991A - Motion adaptive three-dimensional y/c separator circuit - Google Patents

Abstract

PURPOSE:To reduce a memory capacity as a frame delay means by decoding a frequency band with Y and C signals frequency-multiplied so as to be returned to a carrier chrominance signal after Y/C separation. CONSTITUTION:An animation picture Y/C separator circuit 3 extracts the vertical high-band component of an input composite video signal and a BPF 6 outputs a moving picture C signal to a mixing circuit 45. A motion detection circuit 11 outputs a motion detection signal by using the frame correlation of a signal with the low-pass component of the luminance signal from an LPF 7 thinned out. A demodulation circuit 18 demodulates a signal not including the low pass component of the luminance signal by a signal synchronized with the color carrier. A color difference signal is processed by LPF 19 and 20, thinning circuits 21 and 22, frame memories 23 and 24, adders 25 and 26, interpolation filters 39 and 40. A modulation circuit 41 returns a color difference signal to a carrier color signal, and a BPF 42 outputs a still picture C signal. An adder 14 adds the low pass component of the luminance signal from the interpolation filter 13 to output a still picture Y signal to a mixing circuit 43.

Description

[Detailed description of the invention]

[Purpose of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion-adaptive three-dimensional Y/C separation circuit for separating motion-adaptive luminance signals and color signals.

0002

2. Description of the Related Art For the purpose of improving Y/C separation performance, a motion adaptive three-dimensional Y/C separation circuit has been developed for TV,
It is beginning to be installed in VTRs, etc. This basically detects the movement of the input composite video signal based on the size of the frame difference value, and uses line correlation to perform Y/C separation on the portion detected as a video (video portion), and performs Y/C separation on the still image. The portion determined to be the same (still image portion) is subjected to Y/C separation using frame correlation. For example, the development of LSI was reported at the national conference of the TV Society in 1989.
Miyazaki et al.: “Development of 3D YC processing LSI”, P21
5-p216).

[0003] Hereinafter, the above-mentioned conventional example in which the conventional three-dimensional Y/C separation circuit operates will be described with reference to a block diagram showing the basic configuration of FIG.

The input analog composite video signal is A
/D converter 101. The A/D converter 101 converts an analog composite video signal into a digital signal and outputs it to a moving image Y/C separation circuit 102 and a 1 horizontal scanning period delay circuit 103 (hereinafter referred to as 1H delay circuit 103). The 1H delay circuit 103 delays the digitized composite video signal by one horizontal scanning period and outputs the video Y/C separation circuit 102, the 1H delay circuit 104, and the 1 frame delay circuit 1.
05, Y/C separation circuit for still images 107, motion detection circuit 10
8, output to the subtracter 111. The 1H delay circuit 104 is
The signal delayed by the 1H delay circuit 103 is further delayed by one horizontal scanning period and output to the moving image Y/C separation circuit 102.

[0005] A video Y/C separation circuit 102 uses the signals from the A/D converter 101 and the 1H delay circuits 103 and 104 to extract vertical high frequency components by utilizing the vertical correlation of the three lines of signals. bandpass filter 110 (hereinafter referred to as BPF)
110). The BPF 110 separates the color subcarrier band component from the extracted vertical high-frequency component, and generates a moving image C, which is a color signal at the time of a moving image, through a subtracter 111 and a mixing circuit 1.
Output to 12. The subtracter 111 subtracts the signal of the moving image C from the signal from the 1H delay circuit 103 to separate the moving image Y, which is a luminance signal during the moving image, and outputs it to the mixing circuit 113.

The 1-frame delay circuit 105 further delays the signal from the 1H delay circuit 103 by 1 frame to provide a 1-frame delay circuit 106, a still image Y/C separation circuit 107,
It is output to the motion detection circuit 108. 1 frame delay circuit 1
06 further delays the signal from the one frame delay circuit 105 by one frame and outputs it to the motion detection circuit 108.

The still image Y/C separation circuit 107 separates and mixes the still image Y, which is the luminance signal during still images, by substantially adding the signal from the 1H delay circuit 103 and the signal from the 1 frame delay circuit 105. The signal is output to the circuit 113, and the color signal component (frame uncorrelated component) is separated by substantial subtraction of the two signals and output to the BPF 109. B.P.
F12 outputs to the mixing circuit 112 a still image C, which is a color signal for a still image obtained by band-limiting this color signal component.

The motion detection circuit 108 includes a 1H delay circuit 10
3, the signal from the 1-frame delay circuit 105, and the signal from the 1-frame delay circuit 106 are input,
A motion signal detected based on the difference value between one frame from the 1H delay circuit 103 and the one frame delay circuit 105, and a motion signal detected based on the difference value between one frame from the one frame delay circuit 105 and the one frame delay circuit 106. Among the detected motion signals, a signal indicating a large motion is selected and output as a motion signal to mixing circuits 112 and 113.

[0009] The mixing circuit 113 mixes the moving image Y and the still image Y at a ratio according to the motion signal, and outputs it to the D/A converter 115 as a Y/C separated Y signal. D/A converter 115
converts the digital Y signal into an analog Y signal and outputs it. Then, the mixing circuit 112 mixes the moving image C and the still image C at a ratio according to the motion signal, and outputs it to the D/A converter 114 as a Y/C separated C signal. D/A converter 11
4 converts the digital C signal into an analog C signal and outputs it.

Next, the operation of the Y/C separator constructed as described above will be explained.

The composite video signal input to the A/D converter 101 is converted into a digital composite video signal and is converted into a Y/D video signal for moving pictures.
The signal is output to a C separation device 116 and a Y/C separation device 117 for still images. The moving picture Y/C separator 116 separates this signal into a digital moving picture Y signal and a moving picture C signal using line correlation, and mixes the signals in a mixing circuit 113 and a mixing circuit 1, respectively.
Output to 12. Further, the still image Y/C separator 117 separates the digital composite video signal into a digital still image Y signal and a still image C signal using frame correlation, and outputs them to the mixing circuit 113 and the mixing circuit 112, respectively. The motion detection circuit 108 generates a motion signal from the current composite video signal of the 1H delay circuit 103 and the composite video signals of the 1H delay circuit 103 of one frame and two frames ago according to the ratio of moving image and still image to a mixing circuit 112 and a mixing circuit 113. Output to. The moving image Y and the still image Y are mixed by a mixing circuit 113 at a ratio according to the motion signal, converted into an analog Y signal by a D/A converter 115, and output. The moving image C and the still image C are mixed by a mixing circuit 112 at a ratio according to the motion signal D/
The A converter 114 converts it into an analog C signal and outputs it.

The problem here is the capacity of the frame memory as the frame delay means. Usually, several 1M bit memories are used as this frame delay means. Although the price of memory is decreasing, it is still expensive and memory accounts for a large proportion of the cost, and motion adaptation 3
The dimension Y/C separation circuit is the Y/C separation circuit of the conventional line comb filter.
This causes a significant increase in cost compared to the /C separation circuit. Furthermore, this also results in an increase in the mounting area of the board and an increase in power consumption.

Then, in order to reduce the capacity of the frame memory, which is a problem, if only the band in which the Y signal and the C signal are frequency-multiplexed is subjected to frame calculation (passed through the frame memory), fast movements cannot be detected, and The S/N of the low frequency part where frame calculation is not performed was degraded.

[0014]

[Problems to be Solved by the Invention] As described above, the conventional motion-adaptive three-dimensional Y/C separation circuit requires more expensive memory as a frame delay means than the line-comb type filter Y/C separation circuit, resulting in a significant cost increase. This also increases the board mounting area and power consumption.

[0015] In order to reduce the capacity of the frame memory, which is a problem, if only the band in which the Y signal and the C signal are frequency-multiplexed is subjected to frame calculations (passed through the frame memory), fast movements cannot be detected, and There has been a problem in that the S/N of the low frequency portion that is not subjected to frame calculation is degraded.

The present invention eliminates the drawbacks of the prior art as described above, and in a motion adaptive three-dimensional Y/C separation circuit, requires less memory capacity as a frame delay means, which is the cause of a significant increase in cost. Motion adaptive three-dimensional Y/
The purpose of the present invention is to provide a C separation circuit.

[Configuration of the invention]

[0018]

[Means for Solving the Problems] In order to achieve the above object, the present invention extracts the low frequency component of a luminance signal from an input composite video signal, and produces a thinned luminance low frequency signal and a one frame delayed signal. outputting a first luminance signal by adding the luminance low-band signals and interpolating the signal;
a motion detection means for detecting motion by a difference obtained by subtraction and outputting a motion detection signal;
two-dimensional Y/C separation means for separating and outputting color signals;
The input composite video signal is demodulated and thinned out using a signal synchronized with the color subcarrier, the thinned out signal and the signal delayed by one frame are calculated, and modulated with a signal synchronized with the color subcarrier to generate a second signal. 3D Y/C that separates and outputs color signals
separating means, the composite video signal, the first color signal from the two-dimensional Y/C separating means, the second color signal from the three-dimensional Y/C separating means, and the second color signal from the motion detecting means; Motion adaptation characterized by comprising: a mixing means that receives the first luminance signal and the motion detection signal, performs a predetermined calculation, and outputs a second luminance signal and a third color signal adapted to the motion. Provides a three-dimensional Y/C separation circuit.

[0019]

[Operation] In the device configured in this way, the frequency band in which the Y signal and C signal are frequency multiplexed in the composite video signal is demodulated, and this demodulated signal is subjected to Y/C separation by interframe calculations. The demodulated color signal obtained through processing is modulated and returned to the carrier color signal.

[0020] Since it is sufficient to store signals in the frequency band in which the Y signal and the C signal are frequency-multiplexed in the memory as a frame delay means necessary for inter-frame calculations, the frequency of the entire composite video signal is The memory capacity is reduced by the ratio between the frequency band and the frequency band in which the Y signal and C signal are frequency multiplexed, and actually by the ratio of the frequency of the sampling clock required to pass the signal in this frequency band without distortion. can.

[0021] In a signal in a frequency band in which the Y signal and C signal are frequency multiplexed, the phase of the color subcarrier is inverted for each frame, so motion cannot be detected unless the difference value between the two frames is obtained. Unable to detect fast movements. However, in the above configuration, since motion is detected using the low-frequency component of the Y signal, in which the Y signal and the C signal are not frequency multiplexed, fast motion detection for each frame is also possible, and there is no deterioration in motion detection performance.

Furthermore, since noise is removed from the low-frequency components used for motion detection by calculation between frames, there is no deterioration in S/N of the low-frequency components of the luminance signal during still images.

[0023]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 3.

First Embodiment FIG. 1 is a block diagram showing a first embodiment of the present invention.

The composite video signal input from the input terminal 1 is
The signal is supplied to the A/D converter 2. The A/D converter 2 converts the composite video signal into a digital signal and outputs it to the moving image Y/C separation circuit 3 and the 1H delay circuit 4. 1H delay circuit 4
, the digital signal from the A/D converter 2 is delayed by one horizontal scanning period, and the video Y/C separation circuit 3, 1H delay circuit 5, low pass filter 7 (hereinafter referred to as LPF 7), adder 16, and Output to 17.

The video signal generating section will be explained below.

The 1H delay circuit 5 further delays the composite video signal from the 1H delay circuit 4 by one horizontal scanning period to produce Y for moving pictures.
/C output to separation circuit 3. The video Y/C separation circuit 3 uses the signal from the A/D converter 2 and the signals from the 1H delay circuits 4 and 5 to perform calculations using the vertical correlation of the 3-line signals, and extracts vertical high-frequency components. is extracted and output to BPF6. The BPF 6 extracts components of the color subcarrier band and outputs a moving image C signal, which is a color signal for moving images, to the subtracter 16 and the mixing circuit 45. The subtracter 16 converts the composite video signal from the 1H delay circuit 4 into a moving image C, which is the output signal of the BPF 6.
The signals are subtracted, and a moving image Y signal, which is a luminance signal during moving images, is output to the mixing circuit 43.

The motion detection operation section will be explained below.

The thinning circuit 8 thins out the low-frequency components of the luminance signal from the LPF 7 and outputs a signal with a lower sampling clock frequency to the frame memory 9, the subtracter 10, and the adder 12. Frame memory 9 delays the thinned out signal by one frame and outputs it to subtracter 10 and adder 12.

The subtracter 10 outputs a difference value between one frame, which is the difference between the two input signals, to the motion detection circuit 11. Ignoring the influence of noise, the difference value between one frame is zero for a completely still image, and is a finite value for a moving image, and the greater the movement, the larger the difference value for one frame. The motion detection circuit 11 converts the difference signal between one frame obtained from the subtractor 10 into a motion detection signal K (the value of the motion detection signal K is 0 to 1, K=0 for a completely still image and K=0 for a complete moving image).
1) and output to mixing circuits 43 and 45.

The still image signal generating section will be explained below.

The LPF 7 outputs the composite video signal from the 1H delay circuit 4 to the thinning circuit 8 and the subtracter 17 as a low frequency component of the luminance signal, which is band-limited to a low frequency that does not contain the color signal. The subtracter 17 subtracts the low-frequency component of the luminance signal, which is the output signal of the LPF 7, from the composite video signal from the 1H delay circuit 4, and generates a composite video signal that does not include the low-frequency component of the luminance signal. Output to 18.

The demodulation circuit 18 demodulates the signal from the subtracter 17 using a signal synchronized with the color subcarrier on two orthogonal color difference axes, and sends the two color difference signals, which are still frequency multiplexed with the Y signal, to the LPFs 19 and 20. Output to. The LPF 19 band-limits the color difference signal to a low frequency band and outputs it to the thinning circuit 21 . The thinning circuit 21 thins out the band-limited color difference signal and outputs it to the frame memory 23 and the adder 25.

[0034] Since the two color difference signals thinned out after the above band limiting have a narrower band than the input composite video signal,
The frame memory 23 lowers the sampling clock frequency by this amount, delays the signal by one frame, and outputs the signal to the adder 25. The adder 25 adds the signal from the thinning circuit 21 and the frame-correlated signal from the frame memory 23 delayed by one frame, and outputs a color difference signal from which the Y signal has been removed to the interpolation filter 39. . The interpolation filter 39 interpolates the thinned out data and outputs it to the modulation circuit 41 at the original sampling clock frequency.

Between the demodulation circuit 18 and the modulation circuit 41, there are provided an LPF 19 and an LPF 20, a decimation circuit 21 and a decimation circuit 22, a frame memory 23 and a frame memory 24, an adder 25 and an adder 26, an interpolation filter 39 and an interpolation filter 40. Another circuit corresponding to each is connected in the same manner as above, and another color difference signal is processed.

The modulation circuit 41 orthogonally modulates the two input color difference signals using two orthogonal signals synchronized with the color subcarrier, returns the signal to a carrier color signal, and outputs the signal to the BPF 42 . B
The PF 42 band-limits the input carrier color signal and outputs a still image C signal, which is a color signal for a still image, to the mixing circuit 45 and the subtracter 15 . The subtracter 15 subtracts the still image C signal from the composite video signal that does not include the low-frequency component of the luminance signal from the subtracter 17, and produces a still image Y signal which is a luminance signal at the time of a still image from which the still image C signal has been removed. A signal lacking low-frequency components is output to the adder 14.

The adder 12 adds the two input signals and outputs the low-frequency component of the luminance signal with improved S/N to the interpolation filter 13. The interpolation filter 13 interpolates the thinned out data and outputs it to the adder 14 at the original sampling clock frequency. Adder 14 is subtracter 1
A still image Y signal having a full band obtained by adding the signal lacking the low frequency component of the still image Y signal from 5 and the low frequency component of the luminance signal from the interpolation filter 13 is output to the mixing circuit 43.

Processing sections for the moving image Y signal, the still image Y signal, the moving image C signal, and the still image C signal will be explained below.

The mixing circuit 43 converts the moving image Y signal and the still image Y signal into K and (1-K), respectively, according to the motion detection signal.
The mixed signals are mixed at a ratio of and output to the D/A converter 44. The D/A converter 44 converts the digital Y signal into an analog Y signal and outputs it. The mixing circuit 45 converts the moving image C signal and the still image C signal into K and (1-), respectively, according to the motion detection signal.
K) and output to the D/A converter 46. D/
The A converter 46 converts the digital C signal into an analog C signal and outputs it.

Next, the operation of the motion adaptive three-dimensional Y/C separation circuit configured as described above will be explained.

The analog composite video signal input to the A/D converter 2 is converted into a digital signal, and the video signal generation section and still image signal generation section demodulate the video Y signal and video C signal, respectively. A motion detection signal K is extracted from the separated still image Y signal and still image C signal, and the low frequency component of the Y signal by a motion detection operation section. Mixing circuit 4
3 and 45 detect the moving image Y signal, the still image Y signal, the moving image C signal, and the still image C signal by the motion detection signal K, respectively.
/A converters 44 and 46, where they are converted into analog Y and C signals, respectively.

Second Embodiment FIG. 2 is a block diagram showing a second embodiment according to the present invention, and parts that overlap with those of the first embodiment are given the same numbers and their explanation will be omitted.

The difference between this embodiment and the first embodiment is the motion detection method. In the first and second embodiments, motion is detected based on the difference value between frames of the low-frequency component of the composite video signal, that is, the low-frequency component of the Y signal. This allows fast movement to be detected. Although this method of detecting motion does not pose any problem on a normal screen, it becomes a problem when the motions of the low frequency component and the color signal band component, that is, the Y signal and the C signal are different. Therefore, in the second embodiment, the movement of the color signal band components is also detected by determining the difference value between two frames of demodulated color difference signals. The rest is the same as the first embodiment, so only motion detection will be explained.

The output signal of the thinning circuit 21 is input to a frame memory 27, an adder 31, and a subtracter 33. Frame memory 27 delays the signal input from thinning circuit 21 by one frame and outputs the signal to adder 31 and frame memory 29 . Adder 31 is thinning circuit 21
The signals inputted from the frame memory 27 and the frame memory 27 are added together and outputted to the interpolation filter 39. Frame memory 29 further delays the signal input from frame memory 27 by one frame and outputs the delayed signal to subtracter 33 . The subtracter 33 subtracts a signal obtained by delaying this signal by two frames by the frame memories 27 and 29 from the signal input from the thinning circuit 21, and calculates the difference value between the two frames to the motion detection circuit 1.
Output to 1.

[0045] Then, the decimation circuit 21 and the interpolation filter 39
Similarly to the above, the decimation circuit 22 and the interpolation filter 40
In between, another circuit in which the frame memory 27 and the frame memory 28, the frame memory 29 and the frame memory 30, the adder 31 and the adder 32, and the subtracter 33 and the subtracter 34 correspond to each other is connected in the same manner as above. Then, another color difference signal is processed.

By further delaying the outputs of frame memories 27 and 28 by one frame in frame memories 29 and 30, two color difference signals delayed by two frames are obtained. The subtracters 33 and 34 then calculate the difference values between two frames of the two color difference signals and output them to the motion detection circuit 11.

In the process of demodulation, the color difference signals have frame correlation, and conversely, the phase of the Y signal is inverted for each frame, so motion cannot be detected from the difference value between one frame of the demodulated signal (one frame The difference value between the two frames includes both the movement of the color difference signal and the Y signal), but since the phase of the Y signal returns in the second frame, the demodulated signal has a correlation between the two frames, and the difference between the two frames Movement can be detected by value.

The motion detection circuit 11 converts the difference signal between one frame obtained from the subtracter 10 and the difference signal between two frames obtained from the subtractors 33 and 34 into motion detection signals, and converts these motion detection signals into motion detection signals. The signal indicating the largest movement is selected and output as the final motion detection signal K to mixing circuits 43 and 45.

The reason why the motion detection circuit 11 gives priority to signals on the motion side is that in a motion detection error, failure to detect motion causes more damage to the screen. Although the Y/C separation performance deteriorates even if a still image is mistakenly detected as a moving image, the performance of conventional Y/C separation using line correlation is maintained. However, if motion is not detected and a video is mistaken for a still image, a large part of the screen will be affected by afterimages, resulting in a major failure.

Third Embodiment FIG. 3 is a block diagram showing a third embodiment of the present invention, and parts that overlap with those of the first embodiment are given the same reference numerals and their explanation will be omitted.

The difference between this embodiment and the first embodiment is the method of passing the demodulated color difference signal through the frame memory and the method of interframe calculation. The rest is the same as the first embodiment, so the explanation will be omitted.

The color difference signals, which are the output signals of the thinning circuits 21 and 22, are input to a multiplexing circuit 35. The multiplexing circuit 35 time-division multiplexes the two color difference signals and outputs them to the frame memory 36 and adder 37, and also sends a multiplexed phase control signal to the separation circuit 38, which conveys the order of multiplexing.
Output to. Frame memory 36 delays the signal input from multiplexer 35 by one frame and outputs the delayed signal to adder 37 . The adder 37 adds the signals input from the multiplexing circuit 35 and the frame memory 36 and outputs a color difference signal from which the luminance signal has been removed to the separation circuit 38.

In the first embodiment, the two demodulated color difference signals are subjected to delay and interframe calculations separately in the frame memory, but in this embodiment, a multiplexing circuit 35 and a separation circuit are installed before and after the frame memory. 38 is provided, and the two color difference signals time-division multiplexed by the multiplexing circuit 35 are delayed by the frame memory and subjected to inter-frame calculations, and then the separation circuit 3
8, the original two color difference signals are separated from the time-division multiplexed signal using the multiplexed phase control signal from the multiplexing circuit 35.

To explain in more detail, assuming that the clock frequency of the composite video signal is 4 fsc (fsc: color subcarrier frequency, approximately 3.58 MHz), and the demodulation axes are I-axis/Q-axis,
The I-axis band is 1.5 MHz (clock frequency fsc, approximately 3.58 MHz), and the Q-axis band is 0.5 MHz (clock frequency 1/3 fsc, approximately 1.2 MHz).

[0055] When LPF 19 is placed on the I-axis side, LPF 19
The I signal, which is band-limited to 1.5MHz, is thinned out by circuit 2.
1, one out of four pieces of data is taken out and the clock frequency is reduced to 1/4 from 4fsc to fsc.

[0056] One out of every 12 pieces of data is taken out in the LPF 20, and the clock frequency is changed from 4fsc to 1/3f.
Drop to 1/12 to sc.

The multiplexing circuit 35 divides the demodulated I signal and demodulated Q signal with a clock frequency of 3:1 using a clock with a frequency four times that of the demodulated Q signal, and divides the I signal into three and the Q signal into one signal. A time-division multiplexed signal with a clock frequency of 4/3 fsc is created by switching and multiplexing the signals.

After performing inter-frame calculations on this time-division multiplexed signal, the separation circuit 38 extracts the I signal from the time-division multiplexed signal with a clock of frequency fsc based on the multiplex switching control signal in the multiplexing circuit 35. Also frequency 1/3fsc
The Q signal is extracted with the clock of , and the I signal and Q signal are separated and sent to interpolation filters 39 and 40, respectively.

In this way, the adder 37 is shared by two color difference signals, the I signal and the Q signal. It is also possible to time-division multiplex the low frequency components of the Y signal, and if the bands of the two color difference signals are selected to be the same, the respective characteristics of the LPFs 19 and 20, the thinning circuits 21 and 22, and the interpolation filters 39 and 40 can be adjusted. can be made the same, so the LPF, decimation circuit, and interpolation filter can also be used in common.

Having described the three embodiments above, the effect of reducing memory capacity according to the present invention will now be described.

Ease of processing, EDTV and S-VHS
・Due to higher resolution of signal sources such as VTRs, even conventional examples have a frequency of 4 fsc (fsc: color subcarrier frequency, approximately 3
．． 58MHz) clock is used.

Conventionally, the required memory capacity is 525 [lines] x 910 [data/data] x 8 [bits/data] = 3,822,000 bits for one frame, assuming that one data is 8 bits. Become.

Similarly, the memory capacity required by the present invention is such that the demodulation axes are the I-axis/Q-axis, the I-axis band is 1.5 MHz (clock frequency fsc), and the Q-axis band is 0.5 MHz. 5MHz (clock frequency 1/3fsc), low frequency component band 1MHz (clock frequency 2/3fsc)
Similarly, if 1 data is 8 bits, I axis: 5
25 [books] x 910 [data/books] x 1/4 x 8 [bits/data] = 955500 bits... (2) Q axis: 52
5 [books] x 910 [data/books] x 1/12 x 8 [bits/data] = 318500 bits... (3) Low frequency component:
525 [books] x 910 [data/books] x 1/6 x 8 [bits/data] = 318,500 bits...(4), and the total is (2) + (3) + (4) = 1911,000 bits in one frame. …(5
) is required.

Therefore, compared to the conventional memory capacity, the memory capacity required by this invention is (5)/(1)=1911000[bits]/3822
000 [bit] = 0.5 (50%)...(5),
The required memory capacity is only half that of the conventional one.

Furthermore, in motion adaptive three-dimensional Y/C separation, motion detection performance is important, but in this invention, one of the low frequency components is
Since motion is detected based on the difference value between frames, there is no performance deterioration due to failure to detect fast motion.

Furthermore, since noise is removed from the low frequency components of the Y signal by interframe calculation, there is no S/N deterioration of the low frequency components.

[0067]

According to the present invention, the memory serving as the frame delay means stores only the low frequency component of the luminance signal and the color signal, so that the memory capacity can be reduced. Therefore, in the motion adaptive three-dimensional Y/C separation circuit, it is possible to reduce the memory capacity as a frame delay means, which is the cause of a significant increase in cost. Furthermore, since motion is detected using the low-frequency component of the Y signal, in which the Y signal and the C signal are not frequency-multiplexed, it is also possible to detect fast motion for each frame. Further, there is no S/N deterioration in the low frequency component of the luminance signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a motion adaptive three-dimensional Y/C separation circuit according to the present invention.

FIG. 2 is a block diagram of another embodiment of a motion adaptive three-dimensional Y/C separation circuit according to the present invention.

FIG. 3 is a block diagram of another embodiment of the motion adaptive three-dimensional Y/C separation circuit according to the present invention.

FIG. 4 is a block diagram of a conventional motion adaptive three-dimensional Y/C separation circuit.

[Explanation of symbols]

3 Video Y/C separation circuit 4, 5 1H delay circuit 6, 42 BPF 7, 19, 20 LPF 8, 21, 22 Thinning circuit 9, 23, 24 Frame memory 10, 15, 1
6, 17 Subtractor 11 Motion detection circuit 12, 14, 25, 26 Adder 13, 39, 4
0 Interpolation filter 18 Demodulation circuit 41 Modulation circuits 43, 45 Mixing circuit

Claims (1)

[Claims] 1. A luminance low-frequency signal obtained by extracting a low-frequency component of a luminance signal from an input composite video signal and adding the luminance low-frequency signal delayed by one frame to interpolate the signal. a motion detection means that outputs a first luminance signal, detects motion by a difference obtained by subtraction, and outputs a motion detection signal; C separation means demodulates and thins out the input composite video signal with a signal synchronized with the color subcarrier, calculates this thinned out signal and a signal delayed by one frame, and modulates it with a signal synchronized with the color subcarrier. a three-dimensional Y/C separating means for separating and outputting a second color signal; and a three-dimensional Y/C separating means for separating and outputting a second color signal; The second color signal from the separation means, the first luminance signal and the motion detection signal from the motion detection means are input, and predetermined calculations are performed to obtain a second luminance signal and a third luminance signal adapted to the motion. A motion-adaptive three-dimensional Y/C separation circuit comprising: mixing means for outputting a color signal.