JPH09149428A - Separating device of luminance signal and chrominance signal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a separation luminance signal which does not generate after image interference by separating a motion leakage component by the low-pass filter in a narrow band and subtracting the motion leakage component from a one-frame difference signal. SOLUTION: This device delays an inputted composite video signal by one frame by a one-frame delaying device 4 and takes the difference between signals before and after it by a subtracter 5 to obtain the one-frame difference signal. After making the one-frame difference signal pass through a first low-pass filter 7, the device detects not less than a prescribed level by a threshold value level generator 8 and a subtracter 9 to obtain a motion detection signal. In addition, the device makes the one-frame difference signal pass through the second low-pass filter 50 of the narrow band so as to separate the motion leakage component of the luminance signal and subtracts the motion leakage component from the one-frame difference signal by a subtracter 51 to obtain a still chrominance signal which does not include the motion leakage component. Then the device subtracts the still chrominance signal which does not include the motion leakage component from the composite video signal by a subtracter 13 to obtain the separation luminance signal which does not generate after image interference.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a luminance signal / color signal separation device by three-dimensional processing utilizing inter-frame correlation.

[0002]

2. Description of the Related Art In recent years, a luminance signal / color signal separating device has been remarkably improved in performance by digital processing, and in particular, three-dimensional processing using frame correlation is generally put into practical use even at a consumer level in accordance with a reduction in price of an image memory. Is being done. As a conventional luminance signal / color signal separation device, for example, Japanese Patent Laid-Open No. 1-1
No. 74088.

A conventional luminance signal / color signal separation device will be described below. FIG. 5 is a block diagram of a conventional luminance signal / color signal separation device. In FIG. 5, reference numeral 1 is an input terminal for inputting a composite video signal. A color signal output terminal 2 outputs a separated color signal. A luminance signal output terminal 3 outputs a separated luminance signal. Reference numeral 4 is a one-frame delay device, which delays the input composite video signal by one frame. A subtracter 5 subtracts the input composite video signal and the composite video signal delayed by one frame to obtain a one-frame differential signal. 6 is a motion detection circuit, which is composed of a low-pass filter 7, a threshold level generator 8, a subtractor 9, and a space-time filter 10.
A motion detection signal is obtained from the 1-frame difference signal. Reference numeral 11 denotes a two-dimensional color signal separation circuit by in-field processing, which obtains a moving color signal which is a color signal during movement from the input composite video signal. Reference numeral 12 denotes a switcher, which uses the one-frame difference signal as a still color signal which is a color signal at the time of stillness, and switches the moving color signal according to the motion detection signal to obtain a separated color signal.
Reference numeral 13 denotes a subtractor, which obtains a separated luminance signal by subtracting the separated color signal from the composite video signal.

The operation of the luminance signal / chrominance signal separation device having the above configuration will be described below. First, the composite video signal input from the input terminal 1 is delayed by 1 frame by the 1-frame delay unit 4 and then subtracted from the original composite video signal by the subtractor 5 to obtain a 1-frame difference signal. . Since this composite video signal has a perfect frame correlation if it is a still image signal, the one-frame difference signal is only a perfect still color signal. However, in the case of a moving image signal, this one-frame difference signal is a signal in which the motion component of the luminance signal and the static component of the color signal are mixed. Therefore, the low-pass filter 7 separates only the low-frequency motion component of the luminance signal from the one-frame difference signal, and the subtracter 9 compares it with the threshold value of the threshold level generator 8. If it is above the threshold level, it is determined that motion has occurred, and the output is subjected to integration processing by the space-time filter 10 to obtain a motion detection signal.

When the motion detection signal is not output, it is considered to be stationary, and the switch 12 is switched to the S side, and the one-frame difference signal which is a still color signal is used as a separation color signal to output the color signal output terminal 2 Output to. Further, when the motion detection signal is output, it is assumed that the motion is in progress, and the switch 12 is switched to the M side, and the two-dimensional color signal separation circuit 11 is switched.
The moving color signal thus obtained is output to the color signal output terminal 2 as a separated color signal.

On the other hand, the separated luminance signal is obtained by subtracting the separated color signal from the composite video signal in the subtractor 13, and is output to the luminance signal output terminal 3. Next, another example of the conventional luminance signal / color signal separation device will be described. FIG.
5 is a block diagram of another example of the conventional luminance signal color signal separation device, in which the capacity of the image memory used in the one-frame delay unit 4 is reduced as compared with the conventional luminance signal color signal separation device in FIG. The thinning process is used to do this. 6, the same components as those in FIG. 5 are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 6, reference numeral 21 denotes a first decimation processing circuit, which decimates a composite video signal sampled with a clock of a subcarrier multiplication frequency in accordance with the subcarrier phase. Reference numeral 22 is a first one-frame delay device, which delays the thinned composite video signal by one frame.
Reference numeral 23 denotes a subtracter, which takes the difference between the composite video signal subjected to the thinning process and the composite video signal delayed by one frame,
A thinned-out 1-frame difference signal is obtained. Reference numeral 24 denotes a first interpolation processing circuit, which performs interpolation processing so that the thinned-out 1-frame difference signal has the original sampling rate to obtain a still color signal. A low-pass filter 25 separates the low-pass component of the luminance signal from the composite video signal. A second thinning-out processing circuit 26 thins out the sampling rate of the separated luminance signal low-frequency component. Reference numeral 27 is a second one-frame delay device that reduces the luminance signal low-frequency component that has been subjected to the thinning-out process to 1
Delay by the number of frames. Reference numeral 28 denotes a subtracter, which obtains a thinned-out luminance signal low-frequency motion component by taking the difference between the luminance signal low-frequency component subjected to the thinning process and the luminance signal low-frequency component delayed by one frame. Reference numeral 29 denotes a second interpolation processing circuit, which interpolates the thinned-out luminance signal low-frequency motion component so that the original sampling rate is obtained, and obtains a luminance signal low-frequency motion component.

The operation of the luminance signal / chrominance signal separation device having the above configuration will be described below with reference to FIG. FIG. 7 is a reference diagram showing an example of a state of thinning processing in the conventional luminance signal / color signal separation device shown in FIG. First, the composite video signal input from the input terminal 1 is sampled with a clock of 4 times the subcarrier, as shown in FIG. Then, this composite video signal is thinned by the first thinning-out processing circuit 21 to 1/2 around the subcarrier frequency as shown in FIG. 7B. Thereafter, the first 1-frame delay unit 22 delays by 1 frame, and the subtractor 23 subtracts from the composite video signal that has been subjected to the original thinning process.
The frame difference signal is obtained, and further the first interpolation processing circuit 24
By performing interpolation processing so that the original sampling rate is obtained, a one-frame differential signal is obtained. This one-frame difference signal is thinned out in the middle, so that a slight aliasing distortion component is generated, but it is thinned out around the sub-carrier frequency, and the band limitation by the filter is performed. Since it is not applied at all, almost perfect still color signals can be obtained.

The composite video signal has a low-pass filter 2
5, the luminance signal low-frequency component is separated, and the second thinning-out processing circuit 26 divides it into 1/4 as shown in FIG. 7 (c).
Is thinned out. Thereafter, the second 1-frame delay unit 27 delays the frame by 1 frame, and the subtractor 28 subtracts it from the original thinned composite video signal to obtain a thinned-out luminance signal low-frequency motion component. The second interpolation processing circuit 29 performs the interpolation processing so that the original sampling rate is obtained, thereby obtaining the luminance signal low-frequency motion component. The luminance signal low-frequency motion component is subjected to decimation processing in the middle, but since the sub-Nyquist band is band-limited in advance by the low-pass filter 25, it is exactly the same as when no decimation processing is performed. A luminance signal low-frequency motion component is obtained. Therefore, it is compared with the threshold value by the threshold level generator 8 in the subtractor 9, and if it is above the threshold level, the output is integrated by the spatiotemporal filter 10 as if motion has occurred. A motion detection signal is obtained by performing the processing.

When the motion detection signal is not output, it is considered to be stationary, and the switch 12 is switched to the S side, and the still color signal is output to the color signal output terminal 2 as a separated color signal. Further, when the motion detection signal is output, it is considered that the motion is in progress, and the switch 12 is switched to the M side, and the moving color signal obtained from the two-dimensional color signal separation circuit 11 is used as the separation color signal to output the color signal output terminal 2 Output to.

Further, the separated luminance signal is obtained by subtracting the separated color signal from the composite video signal in the subtractor 13, and is output to the luminance signal output terminal 3. By using the decimation process in this way, it is possible to realize a decimation of ½ in the first 1-frame delay unit 22 and a quarter in the second 1-frame delay unit 27, that is, a total of 3/4 decimation. , The image memory capacity can be reduced to 3/4 as compared with the case where no thinning is performed.

[0012]

However, in the above-described conventional configuration, the luminance signal low-frequency motion component is compared with the threshold value by the threshold level generator 8 in the subtractor 9, and if it is equal to or higher than the threshold level. If there is a luminance signal low-frequency motion component, since it is configured to obtain a motion detection signal if it exists, if it is below the threshold value, the motion detection signal cannot be obtained and the motion detection signal is detected. A leak occurs.

Therefore, in the luminance signal / chrominance signal separation device shown in FIG. 5, the afterimage interference of the luminance signal occurs due to this motion detection omission, and in the luminance signal / color signal separation device shown in FIG. There is a problem that the low-frequency component of the luminance signal is folded back into the still color signal due to omission of detection, resulting in interference of the false color signal. To solve this problem, the threshold level should be lowered significantly, but then the noise contained in the input composite video signal will increase the probability that a motion detection signal will be generated even when stationary. The three-dimensional processing effect is reduced.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, according to the present invention, after passing a one-frame differential signal through a first low-pass filter, a further one The motion color leak component of the luminance signal is separated by passing it through a second narrow band low-pass filter, and the motion color leak component is subtracted from the one-frame difference signal to remove the luminance signal motion leak component. Then, by subtracting this still color signal from the original composite video signal, it is possible to obtain a separated luminance signal in which afterimage interference does not occur.

Further, the low-pass 1-frame difference signal after passing the composite video signal through the first low-pass filter is passed through a second low-pass filter having a narrower band than that of the first low-pass filter. As a result, by separating the motion leakage component of the luminance signal and then subtracting it from the one-frame difference signal, it is possible to obtain a separated color signal in which no false color signal interference occurs.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a frame delay means for delaying an input composite video signal by one frame and obtaining a one-frame difference signal by obtaining a difference between signals before and after the first and second frame difference signals. After passing through the first low pass filter, the motion detection means for obtaining a motion detection signal by detecting a predetermined level or more,
The motion leak component of the luminance signal by passing through a second low pass filter having a narrower band than the low pass filter of No. 1 and a still color signal is obtained by subtracting the motion leak component from the one-frame difference signal. And a motion leakage component removing means.

With this configuration, the motion leakage signal removing means separates the motion leakage component from the one-frame difference signal by the second low-pass filter having a narrower band than the first low-pass filter, and the motion leakage component is separated. By subtracting the component from the one-frame difference signal, a static color signal containing no motion leakage component is obtained. Then, by subtracting the still color signal containing no motion leakage component from the composite video signal, a separated luminance signal in which afterimage interference does not occur can be obtained.

Further, the input composite video signal is sampled in synchronization with the subcarrier and the first thinning means for thinning it out according to the subcarrier phase and the output of the first thinning means are delayed by one frame, First frame delay means for obtaining a one-frame difference signal by taking the difference between the signals before and after the signal, and the sampled composite video signal through a first low-pass filter, and then a second thinning process. Give and output 1
A second frame delay unit that obtains a low-frequency 1-frame differential signal by performing frame delay, obtaining a difference between signals before and after the frame, and then performing a second interpolation process according to a second thinning process; A motion detecting means for obtaining a motion detection signal by detecting a predetermined level or more of the 1-frame difference signal and a low-pass 1-frame difference signal to a second low-pass filter having a narrower band than the first low-pass filter. The motion leakage component of the luminance signal is separated by passing it through the first motion leakage component.
After performing the third thinning processing according to the thinning means, 1
A motion leakage component removing means for obtaining a still color signal by subtracting from the frame difference signal and subjecting the output to the first interpolation processing according to the first thinning means.

With this configuration, the motion leakage signal removing means separates the motion leakage component from the low-frequency one-frame differential signal by the second low-pass filter having a narrower band than that of the first low-pass filter. By subjecting the motion leakage component to the third decimation processing according to the first decimation means, subtracting it from the one-frame difference signal, and applying its output to the first interpolation processing according to the first decimation means. Folding luminance signal A still color signal from which low-frequency motion components have been removed is obtained. Therefore, it is possible to obtain the separated color signal in which the false color signal interference does not occur.

[0020]

An embodiment of the present invention will be described below with reference to the drawings. (Embodiment 1) FIG. 1 is a block diagram of a luminance signal / color signal separating apparatus according to an embodiment of the first aspect of the present invention. 1, the same components as those in FIG. 5 are designated by the same reference numerals.

In FIG. 1, reference numeral 1 is an input terminal for inputting a composite video signal. A color signal output terminal 2 outputs a separated color signal. A luminance signal output terminal 3 outputs a separated luminance signal. Reference numeral 4 is a one-frame delay device, which delays the input composite video signal by one frame. A subtracter 5 subtracts the input composite video signal and the composite video signal delayed by one frame to obtain a one-frame differential signal. A motion detection circuit 6 is composed of a first low-pass filter 7, a threshold level generator 8, a subtractor 9 and a space-time filter 10, and obtains a motion detection signal from one frame difference signal.

Reference numeral 50 denotes a second low pass filter, which has a narrower pass band than that of the first low pass filter 7.
The motion leakage component of the luminance signal is separated from the frame difference signal. Reference numeral 51 denotes a subtractor, which obtains a still color signal by subtracting the motion leakage component of the luminance signal from the 1-frame difference signal. Reference numerals 52, 53 and 54 are delay devices for timing adjustment.

Reference numeral 11 denotes a two-dimensional color signal separation circuit by in-field processing, which obtains a moving color signal which is a color signal during movement from the input composite video signal. Reference numeral 12 denotes a switch, which switches a still color signal and a moving color signal in accordance with a motion detection signal to obtain a separated color signal. Reference numeral 13 denotes a subtractor, which obtains a separated luminance signal by subtracting the separated color signal from the composite video signal.

The operation of the luminance signal / color signal separating apparatus having the above-described structure will be described below with reference to FIG. FIG. 2 is a signal spectrum diagram of each part of the luminance signal color signal separation device of the present invention shown in FIG. First,
The composite video signal input from the input terminal 1 has a spectrum in which the luminance signal (Y) and the color signal (C) are mixed, as shown in FIG. This composite video signal is delayed by 1 frame by the 1-frame delay unit 4 and then subtracted from the original composite video signal by the subtractor 5 to obtain a 1-frame differential signal. As shown in FIG. 2B, the 1-frame difference signal is only a complete still color signal (CS) if it is a still image signal, but if it is a moving image signal, it is a motion component of a luminance signal and a color signal. The signal is a mixture of the stationary components of. Therefore, this 1-frame difference signal is converted into (b) of FIG.
First low-pass filter 7 having the characteristics (LPF1) shown in
Separates only the low-frequency motion component (YLM) of the luminance signal,
The subtractor 9 compares it with the threshold K generated by the threshold level generator 8. If the threshold level is exceeded, it is determined that motion has occurred, and the spatiotemporal filter 10 integrates the output. A motion detection signal is obtained by applying. Here, the low-pass filter 7 also applies to the low-frequency component (CL of the static color signal) as shown in FIG.
S) may be passed. However, it is necessary to set the threshold value K so that the motion detection signal is not generated by this component. On the contrary, even in the case of the moving image signal, if the low-frequency motion component (YLM) of the luminance signal is small and is less than or equal to the threshold value K, the motion detection signal is not generated, and therefore the luminance signal low-frequency motion component (YLM) is not generated. ) Becomes a motion leakage component and is mixed in the still color signal, and afterimage interference occurs in the separated luminance signal.

Therefore, the characteristic (LPF2) shown in FIG.
The second low-pass filter 50 having the above is used to separate the motion leakage component of the luminance signal from the one-frame difference signal, and the subtracter 51 subtracts the motion leakage component from the original one-frame difference signal to obtain the luminance signal motion leakage component. To obtain the removed static color signal. When the motion detection signal is not output, it is considered to be stationary, and the switch 12 is switched to the S side to output the still color signal as the separated color signal to the color signal output terminal 2 to output the motion detection signal. When it is moving, the switch 12 is switched to the M side, and the moving color signal obtained from the two-dimensional color signal separation circuit 11 is output to the color signal output terminal 2 as a separated color signal ((in FIG. 2). d)).

On the other hand, the separated luminance signal is obtained by subtracting the separated color signal from the composite video signal in the subtractor 13 and is output to the luminance signal output terminal 3 ((e) in FIG. 2). In the configuration of FIG. 1, the second low-pass filter 50 is provided after the first low-pass filter 7 in separating the motion leakage component of the luminance signal.
The motion leakage component of the luminance signal may be subtracted from the one-frame difference signal, but it may be added to the separated luminance signal only when the motion detection signal is not generated. The effect does not change even if composed.
Therefore, it goes without saying that the configuration of the present invention is not limited to this embodiment.

As described above, according to the present embodiment, the motion leak component is separated by the second low pass filter having a narrower band than the first low pass filter, and the motion leak component is separated by one frame difference. By subtracting from the signal, a static color signal containing no motion leakage component can be obtained, and thereby a separated luminance signal in which afterimage interference does not occur can be obtained. (Embodiment 2) Next, another embodiment of the present invention will be described.

FIG. 3 is a block diagram of a luminance signal / color signal separation device showing another embodiment of the present invention. In the figure, the same components as those in FIG. 6 are designated by the same reference numerals. In FIG. 3, reference numeral 1 is an input terminal for inputting a composite video signal sampled by a clock of a subcarrier multiplication. A color signal output terminal 2 outputs a separated color signal. A luminance signal output terminal 3 outputs a separated luminance signal. Reference numeral 21 denotes a first decimation processing circuit, which decimates the input composite video signal according to the subcarrier phase. Reference numeral 22 is a first one-frame delay device, which delays the thinned composite video signal by one frame. Reference numeral 23 denotes a subtracter, which takes a difference between the composite video signal subjected to the thinning process and the composite video signal delayed by one frame to obtain a thinned one frame difference signal. A motion detection circuit 6 includes a first low-pass filter 25, a second decimation processing circuit 26, a second one-frame delay device 27, a subtractor 28, a second holding processing circuit 29, and a threshold value. It is composed of a level generator 8, a subtractor 9, and a spatiotemporal filter 10, and obtains a motion detection signal from a low-frequency 1-frame difference signal of a luminance signal.

Reference numeral 60 denotes a second low pass filter, which has a narrower pass band than that of the first low pass filter 25.
The motion leakage component of the luminance signal is separated from the low frequency one frame difference signal of the luminance signal. Reference numeral 61 denotes a third thinning processing circuit, which operates in the same manner as the first thinning processing circuit 21. 62
Is a subtractor, which obtains a thinned-out still color signal by subtracting the motion leakage component of the luminance signal from the thinned-out 1-frame difference signal. Reference numerals 63, 64 and 65 are delay devices for timing adjustment.

Reference numeral 24 is a first interpolation processing circuit, which performs interpolation processing so that the thinned still color signal has the original sampling rate. Reference numeral 11 denotes a two-dimensional color signal separation circuit by in-field processing, which obtains a moving color signal which is a color signal during movement from the input composite video signal. 12 is a switch,
A still color signal and a moving color signal are switched according to the motion detection signal to obtain a separated color signal. Reference numeral 13 denotes a subtractor, which obtains a separated luminance signal by subtracting the separated color signal from the composite video signal.

Regarding the operation of the luminance signal / color signal separating apparatus configured as described above, the operation thereof will be described below with reference to FIGS. 4 and 7.
This will be described with reference to FIG. FIG. 4 is a signal spectrum diagram of each part in the luminance signal color signal separation device of the present invention shown in FIG. First, the composite video signal input from the input terminal 1 is, for example, as shown in FIG.
It is sampled with a multiplied clock and has a spectrum in which the luminance signal (Y) and the chrominance signal (C) are mixed as shown in FIG. This composite video signal is decimated by 1/2 in the first decimation processing circuit 21 around the subcarrier frequency as shown in FIG. 7B, and then shown in FIG. As described above, it has a spectrum (Y 'and C') folded in a half band around the subcarrier frequency.
Then, the first 1-frame delay unit 22 delays the frame by 1 frame, and the subtractor 23 subtracts it from the original thinned composite video signal to obtain a thinned-out 1-frame difference signal ((e in FIG. 4). )) Get. The composite video signal is separated by the low-pass filter 25 into the luminance signal low-pass component (YL) as shown in (c) of FIG. 1 as shown in (c) of 7
/ 4 is subjected to thinning processing, and has a spectrum folded back at a frequency of ½ of the subcarrier frequency as shown in (d) of FIG. After that, the second one-frame delay unit 27 delays one frame, and the subtractor 28 subtracts the original thinned-out composite video signal from the original composite video signal to obtain a low-frequency one-frame difference of the thinned-out luminance signal. That is, the thinned luminance signal low-frequency motion component is obtained, and further the second interpolation processing circuit 29 is used.
By performing interpolation processing so that the original sampling rate is obtained, the luminance signal low-frequency motion component is obtained. The luminance signal low-frequency motion component is subjected to decimation processing in the middle, but since the sub-Nyquist band is band-limited in advance by the low-pass filter 25, it is exactly the same as when no decimation processing is performed. A luminance signal low-frequency motion component is obtained. Therefore, it is compared with the threshold value by the threshold level generator 8 in the subtractor 9, and if it is above the threshold level, the output is integrated by the spatiotemporal filter 10 as if the motion is occurring. A motion detection signal is obtained by applying.

On the other hand, in the thinned-out 1-frame difference signal, the thinned-out still color signal component (CS ') has substantially the same frequency as the still-colored signal component when thinning-out is not performed, as shown in FIG. Although it has a spectrum, the motion leakage component (YLM ') of the luminance signal subjected to the thinning processing has a spectrum within the same band as the color signal due to the influence of aliasing due to the thinning processing. As a result, the luminance signal motion leakage component causes a false color signal interference.
The thinned-out luminance signal motion leakage component cannot be separated by frequency division. Therefore, the second low-pass filter 60 having the characteristic (LPF2) shown in FIG. 4 (f) separates the signal (YLM) corresponding to the motion leakage component of the luminance signal from the luminance signal low-pass motion component, The third decimation processing circuit 61 performs the decimation processing shown in FIG. 7B to obtain the thinned luminance signal motion leakage component (YLM ') having the spectrum shown in FIG. Can be obtained.

Then, the subtractor 62 thins out 1
By subtracting from the frame difference signal, a thinned still color signal is obtained, and further, the first interpolation processing circuit 24
By performing the interpolation processing so that the original sampling rate is obtained, the still color signal from which the luminance signal motion leakage component is removed can be obtained. This static color signal has some aliasing distortion components due to the thinning process performed on the way, but is still thinned around the subcarrier frequency, and there is no band limitation by the filter. Since it is not applied, almost perfect still color signals can be obtained.

When the motion detection signal is not output, it is considered to be stationary, and the switch 12 is switched to the S side, and the still color signal is output to the color signal output terminal 2 as a separated color signal. Further, when the motion detection signal is output, it is considered that the motion is in progress, and the switch 12 is switched to the M side, and the moving color signal obtained from the two-dimensional color signal separation circuit 11 is used as the separation color signal to output the color signal output terminal 2 To ((h) in FIG. 4).

Further, the separated luminance signal is obtained by subtracting the separated color signal from the composite video signal in the subtractor 13, and is output to the luminance signal output terminal 3 ((i) in FIG. 4). The configuration of the present invention is not limited to this embodiment, and various modifications can be made. As described above, according to the present embodiment, the motion leakage component is separated from the luminance signal low band 1 frame difference signal by the second low pass filter having a narrower band than that of the first low pass filter, and the motion leak component is separated. After performing the third thinning processing according to the first thinning means on the leak component, the subtracted color signal is subtracted from the one-frame difference signal to obtain a separated color signal in which no false color signal interference occurs.

[0036]

As described above, according to the present invention, the motion leakage component is separated by the narrow band low-pass filter, and the motion leakage component is subtracted from the one-frame differential signal, so that separation that does not cause afterimage interference does not occur. A luminance signal can be obtained. As a result, a higher-performance luminance signal / color signal separation device can be provided.

Further, a motion leak component is separated from the luminance signal low band 1 frame difference signal by a narrow band low pass filter, the motion leak component is subjected to thinning processing, and then subtracted from the 1 frame difference signal. As a result, a separated color signal free from false color signal interference can be obtained. As a result, it is possible to reduce the memory for frame delay without degrading the performance, and it is possible to provide an inexpensive and high-performance luminance signal / color signal separation device.

[Brief description of the drawings]

FIG. 1 is a block diagram of a luminance signal / color signal separation device according to a first embodiment of the present invention.

FIG. 2 is a signal spectrum diagram of each part of the luminance signal / color signal separation device of FIG.

FIG. 3 is a block diagram of a luminance signal / color signal separation device according to a second embodiment of the present invention.

FIG. 4 is a signal spectrum diagram of each part of the luminance signal / color signal separation device of FIG.

FIG. 5 is a block diagram showing an example of a conventional luminance signal / color signal separation device.

FIG. 6 is a block diagram showing another example of a conventional luminance signal / color signal separation device.

7 is a timing diagram for explaining the operation of FIG. 3 or FIG.

[Explanation of symbols]

 1 Input Terminal 2 Color Signal Output Terminal 3 Luminance Signal Output Terminal 4, 22, 27 1 Frame Delay Device 5, 9, 13, 23, 51, 62 Subtractor 6 Motion Detection Circuit 7, 25 First Low-Pass Filter 8 Threshold level generator 10 spatio-temporal filter 11 two-dimensional color signal separation circuit 12 switcher 21 first decimation processing circuit 24 first interpolation processing circuit 26 second decimation processing circuit 29 second interpolation processing circuit 50, 60 Second low-pass filter 61 Third decimation processing circuit

Claims (2)

[Claims] 1. A frame delay means for delaying an input composite video signal by one frame and obtaining a one-frame difference signal by obtaining a difference between signals before and after the composite video signal, and a first low-pass filter for the one-frame difference signal. Motion detection means for obtaining a motion detection signal by detecting a predetermined level or more after passing through a filter, and a second low-pass filter having a narrower band than the first low-pass filter for the one-frame difference signal. To remove a motion leakage component of the luminance signal, and subtract the motion leakage component from the one-frame difference signal to obtain a still color signal, and a motion leakage component removing unit and the input composite video signal within the field. The moving color signal separating means for separating the moving color signal by processing, the still color signal and the moving color signal are switched by the motion detection signal to output the separated color signal. By subtracting the separated chrominance signal from the color signal output means and the input composite video signal, a luminance signal output means for outputting the separated luminance signal, at least with the luminance-chrominance signal separator. 2. An input composite video signal is sampled in synchronism with a subcarrier, and the first thinning means for thinning it out according to the subcarrier phase and the output of the first thinning means are delayed by one frame, 1 by taking the difference between the signals before and after that
First frame delay means for obtaining a frame difference signal; and, after passing the sampled composite video signal through a first low-pass filter, second thinning processing is performed, and its output is set to 1
Second frame delay means for obtaining a low-frequency 1-frame difference signal by performing frame delay, obtaining a difference between the signals before and after the frame delay, and then performing a second interpolation process according to the second thinning process; Motion detecting means for obtaining a motion detection signal by detecting a predetermined level or more of the low-frequency 1-frame differential signal; and a second low-bandwidth narrower than the first low-pass filter for the low-frequency 1-frame differential signal. A motion leak component of the luminance signal is separated by passing it through a band-pass filter, the motion leak component is subjected to a third thinning process according to the first thinning means, and then subtracted from the one-frame difference signal, A motion leakage component removing means for obtaining a still color signal by subjecting the output to a first interpolation processing in accordance with the first thinning means, and a moving color by the intra-field processing from the input composite video signal. The moving color signal separating means for separating the signal, the still color signal and the moving color signal are switched by the motion detection signal, and the color signal output means for outputting the separated color signal and the input composite video signal from the color signal output means. A luminance signal color signal separation device comprising at least luminance signal output means for outputting a separated luminance signal by subtracting the separated color signal.