JPH0748848B2 - Television signal multiplex system - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a television signal multiplexing system, and more particularly to a high frequency band component of a luminance signal having a low frequency without changing the transmission standard of the television standard system. Multiplex into the band,
A high-definition television signal is transmitted.

[Prior Art] The current color television standard system is, as is well known,
The frequency band of the transmission channel is set to 6MHz.

Therefore, the luminance signal has a horizontal spatial frequency of 4.
2MHz or less, for color signals, the color subcarrier frequency is within 4.2MHz above, and the line scanning frequency (15.75KHz) of 455 /
A method of selecting the doubled 3.58 MHz and modulating and multiplexing the two color difference signals I and Q is adopted.

Recently, in order to make a high-definition color television without changing the standard set by the above-mentioned television standard system, the high frequency band component of 4.2 to 6 MHz of the luminance signal which has not been transmitted conventionally is changed to the spatio-temporal frequency. A high-definition color television system for multiplexing and transmitting in a gap has been proposed.

For example, there are the following documents as a multiplex system using a gap in the space-time frequency domain.

1) Method of constructing television signal JP-A-59-171387 2) EDTV signal system having complete compatibility Television Society of Japan Journal Vol.39, No.10, p.35 However, in these methods, multiplexing is performed. When a high-frequency luminance signal is received by an existing color television receiver that has no means for separating it, it appears as a wide striped pattern, and it looks like it flows from top to bottom. It comes to interfere.

Furthermore, since the frequency spectrum of the multiplexed signal is lined up at 15Hz intervals at the position where it is shared with the chrominance carrier frequency, it becomes difficult to separate the high-frequency luminance signal when the luminance signal has a component of 7.5Hz or more. .

Then, in this case, a measure for interrupting the multiplexing of the high-frequency luminance signal was considered, but since this 7.5 Hz frequency is a low frequency that is considerably noticeable from the viewpoint of vision, this measure is considered to be a moving image. There was the inconvenience of returning and blurring at that moment.

[Problem to be Solved by the Invention] Therefore, an object of the present invention is to prevent interference with a received image of a current television receiver even if a high-frequency luminance signal is multiplexed.

Still another object of the present invention is to reduce blurring of a received image in a high definition television receiver even for a moving image.

[Means for Solving Problems] In order to achieve such an object, according to the present invention, the frequency component is generated in a normal image signal in the spatial frequency domain in the current television standard system. An extremely small amount, and even if it occurs, a region that is difficult to see from the human visual characteristics is selected, and the high frequency luminance signal of the television signal is converted and multiplexed.

That is, according to one aspect of the present invention, in a television signal multiplex system in which a color difference signal is modulated with a subcarrier and multiplexed with a low frequency band luminance signal for transmission, the luminance signal Y of the color television is supplied with a horizontal-vertical spatial frequency. With respect to the spatio-temporal frequency domain (Y _L + Y _H ) excluding the diagonal high band (the spatio-temporal filter 1 corresponds in FIG. 4 of the embodiment), and the spatio-temporal filtering means. A high-frequency filtering means (also corresponding to the bandpass filter 47) for filtering the high frequency band component YH of the filtered luminance signal, and the high frequency of the luminance signal filtered by the high-frequency filtering means. Sampling means for sampling the band component signal Y _H with a carrier having an integer multiple n of the horizontal scanning frequency fh (also corresponding to the switch 5), and the phase of the carrier with respect to the sampled carrier nfh * for each field period. Inverted That means (likewise, a phase inversion circuit 8
Means) and the signal Y _H ′ + Y _H sampled by the sampling means and the luminance signal Y _L + Y _H waved by the space-time filtering means (also the adder 6 corresponds to ) And are provided.

Another aspect of the present invention is a television signal multiplex system in which a color difference signal is modulated by a subcarrier and multiplexed into a low frequency band luminance signal and transmitted, in which a luminance signal of a color television is set to a horizontal-vertical spatial frequency. A spatiotemporal filtering means for filtering in a spatiotemporal frequency domain excluding a diagonal high frequency region, and a high-frequency filtering means for filtering a high-frequency band component of a luminance signal filtered by the spatiotemporal filtering means. An amplitude modulation means for amplitude-modulating the high-frequency band component signal of the luminance signal filtered by the high-frequency filtering means with a carrier having an integral multiple of the horizontal scanning frequency, and a phase of the carrier with respect to the amplitude-modulated carrier. It is provided with an inverting means for each field period, an adding means for adding the signal amplitude-modulated by the amplitude modulating means, and the luminance signal filtered by the spatiotemporal filtering means.

Further, the present invention is preferably a motion detecting means (also corresponding to the motion detecting circuit 3) for detecting, for each pixel, whether or not an image is moving based on the luminance signal Y of the color television, and the motion detecting means. Switching means for selectively outputting the output signal of the adding means in the stationary pixel and the luminance signal Y of the color television before inputting to the spatiotemporal filtering means in the moving pixel based on the output of the detecting means (also , And the switch 2 corresponds thereto).

[Operation] In the present invention, as described above, the high-frequency component of the luminance signal is sampled or amplitude-modulated by the carrier having an integral multiple of the horizontal scanning frequency whose phase is inverted for each field.
The sampled or amplitude-modulated high frequency component Y _H ′
Occurs in the high frequency band of the vertical spatial frequency at the same time frequency as the luminance signal component. In the high frequency range in which the high frequency component Y _H ′ is generated, the frequency component is extremely rarely generated in a normal image signal due to the spatiotemporal filtering means and the set value of an integral multiple. Then, even if it occurs further, it is a region that is difficult to see from the human visual characteristics (that is, a diagonal high region related to the horizontal-vertical spatial frequency removed by the spatiotemporal filtering means).
Since the high frequency component Y _H ′ is applied to the current receiver, the influence of the image quality disturbance on the viewer is very small.

Therefore, according to the present invention, a high-definition television which is less likely to interfere with an image received by the current television receiver without changing the transmission standard in the current television broadcasting standard system. Can be transmitted.

Furthermore, there is little blur even for moving images,
A high-definition television that maintains high resolution can be realized.

Further, since the carrier wave having an integral multiple of the horizontal scanning frequency is used to invert the phase for each field frequency, the generation of the carrier wave and the realization of the present invention as a whole in a digital circuit are extremely facilitated.

Further, by utilizing the difference in the spatiotemporal frequency of the high frequency component YH ', the transmission method of the high frequency component of the luminance signal and the transmission method of the high frequency component of the color signal according to the present invention (Japanese Patent Application No. 61-61171).
No.) can be used together. As a result, the transmission band can be expanded for both luminance and color, and the overall image quality of the system can be improved.

[Examples] Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 is a frequency domain layout diagram showing an embodiment of a spectrum of a luminance signal according to the present invention.

In the figure, the horizontal axis represents the horizontal spatial frequency in the horizontal direction of the screen, and the vertical axis represents the vertical spatial frequency.

In the following embodiments of the present invention, a case will be described in which the high frequency component of 4.2 to 6.0 MHz of the luminance signal is multiplexed within the 4.2 MHz band of the current television standard system.

The transmission standard based on the current television standard system does not limit the band in the vertical direction in the spatial frequency domain.

However, general images rarely have high frequency components in both the horizontal and vertical directions, and tentatively,
Even if there is such a component, the human visual characteristics in this region are deteriorated and it is difficult to see.

Therefore, in FIG. 1, even if the band of the luminance signal is limited to the region shown by the sum of the low frequency component Y _L and the high frequency component Y _H of the luminance signal, the deterioration of the image quality is small.

On that, Y _H, that is, the high frequency component of frequency 4.2MHz or more,
Vertical spatial frequency (vertical frequency) 525 / 2cph (cycles per p
icture height) and sampling or amplitude modulation with a carrier wave nf _h ^* having a horizontal frequency nf _h , Y _H folds back to a region Y _H ′ having a low horizontal frequency and a high vertical frequency.

Here, n of nf _h is an integer, and f _h is a horizontal scanning frequency (hereinafter, referred to as horizontal synchronization frequency).

At this time, if n is properly selected, the folded signal Y _H ′ is
4.2MHz, which is the band of the transmission line by the television standard system
It can be arranged in the following areas and in the areas where the above-mentioned visual characteristics are deteriorated.

In this way, Y _H ′ is added to Y _L , which is the low-frequency component of the luminance signal.
If multiplex is transmitted, the high-frequency component of the luminance signal, which has not been transmitted conventionally, can be transmitted without changing the standard of the conventional transmission path, and there is no means for separating Y _H ′. It gives very little interference to the television receiver.

In FIG. 1, n = 455, that is, nf _h = 2f _SC , and the multi-component Y _H ′ is located at 1.2 to 3 MHz. Where f _SC is the color subcarrier frequency.

FIG. 2A is an explanatory diagram showing an example of a method for sampling Y _H.

This method is known as field offset subsampling and is well known.

If we invert the sampling signal of nf _h for each field,
Vertical frequency 525 / 2cph, horizontal frequency nf _h, the sampled signal nf _h
^* , And the sampling pattern by nf _h ^* is shown in FIG. 2 (A).

Also, FIG. 2B is an explanatory diagram of the transmission region in which nf _h ^* is displayed in the three-dimensional space-time frequency domain.

That is, the area that can be transmitted by nf _h ^* can be variously modified in a three-dimensional area, but for example, the area shown by the diagonal lines in the figure can be transmitted.

According to the shaded region, the vertical frequency is 525 / 2cph or less and the horizontal frequency is nf _{h in} the region where the spatiotemporal frequency is 15Hz or less.
The following half area of the spatio-temporal frequency domain can be transmitted.

FIG. 3 is a layout diagram of the transmission area, which is modified so that the transmission area of FIG. 2 (B) is displayed in the three-dimensional space-time frequency domain in accordance with the embodiment of FIG.

The multi-component Y _H ′ is shown in the shaded area and can be transmitted up to 15 Hz as Y _H ′ as described above.

That is, in the case of the conventional method using the space-time frequency gap, the multiple component can generally transmit up to 7.5 Hz, but in the embodiment according to the present invention, it can transmit up to that double of 15 Hz. Therefore, high-definition information is less likely to be lost in moving images than in the conventional method.

In FIG. 3, the low-frequency component Y _L of the luminance signal is also band-limited to 15 Hz or less in the time direction, but when there is a fast motion in the image, the control processing corresponding to that motion causes
By interrupting the multiplexing of Y _H ′, the band limitation of 15 Hz or less as shown in FIG. 3 is eliminated, and thus the luminance signal of 4.2 MHz or less can be prevented from being band limited in the time direction. .

FIG. 4 is a circuit system diagram showing the configuration of an embodiment of the transmitting side according to the present invention.

In the figure, 1 is a space-time filter, 2 is a switch, 3 is a motion detection circuit, 4 is a bandpass filter (BPF), 5 is a switch for offset subsampling, 6 is an adder, and 7 is a control signal generation circuit. , 8 is a phase inversion circuit, 9 is a color modulator, 10 is an adder, and 11 is a low-pass filter (LPF).

Next, the operation will be described in detail with reference to FIG.

The input luminance signal Y is limited by the spatiotemporal filter 1 to a region Y _L + Y _H in which the low frequency component Y _L and the high frequency component Y _H shown in FIG. 3 are added.

For the signal limited to Y _L + Y _H , only the high frequency component Y _H is extracted by the bandpass filter (BPF) 4, and the switching device 5
Sampling is performed in the cycle of the sampling signal nf _h ^* .

Sampling signal nf for offset subsampling
_The horizontal sync signal HD and the vertical sync signal VD are used to invert the phase of _h ^* .

By comparing the phases of HD and VD, it can be determined whether the field is an even field or an odd field.
By the phase inversion circuit 8 controls the phase of nf _h, the nf _h ^*, the switcher 5 are offset subsampling.

Since the frequency signal of nf _h is an integral multiple of the horizontal synchronizing signal HD, it can be easily obtained by a synchronizing oscillator (not shown).

Now, in the output from the switcher 5 subjected to the offset sub-sampling, in addition to the high frequency component Y _H , Y _H is converted by folding and a multiple component Y _H ′ is newly generated.

The output signal Y _L + Y _H from the spatio-temporal filter 1 and the output signal Y _H ′ + Y _H from the switch 5 are added by the adder 6, and further passed through the switch 2 to output the carrier color signal C. After adding by the adder 10, the band is limited to 4.2 MHz or less by the low-pass filter (LPF) 11.

The above-mentioned carrier color signal C is output from the color modulator 9 after the color subcarrier f _SC is modulated with the color difference signals I and Q.

By the above operation, the composite color television signal,
As the luminance signal, Y _H is removed and Y _L and multiple components
Only Y _H ′ is included and extracted.

On the other hand, when there is a fast motion in the image, the switch 2 is switched by the control signal from the motion detection circuit 3, and the input luminance signal Y is taken out as it is.

Now, FIG. 5 (A) is a circuit system diagram showing a configuration of an embodiment of the above-mentioned space-time filter, and FIG. 5 (B).
FIG. 6 is a circuit system diagram showing a configuration of an embodiment of the transversal filter of FIG. 5 (A).

In FIG. 5A, 101 and 102 are 1-field memories, 105, 106 and 108 are 1-line memories, 107 is a 1 / 2-line memory, 103 is an adder, 104 is a divider, 109 to 113 are transversal filters, and 114 is an adder. Is.

Next, the operation of the spatiotemporal filter will be described with reference to FIG.

The input TV luminance signal is stored in the field memory.
As indicated by 101, three scanning lines X _-2 , X ₀ , X ₂ are extracted by the two line memories 105 and 106.

On the other hand, the signal passing through the field memories 101 and 102 and the current signal are further added by the adder 3 and are added by the divider 104 to 1
The two scan lines X ₋₁ and X ₁ are taken out by the 1/2 line memory 107 and the 1 line memory 108.

These are the signals of three consecutive fields of the input television signal to the signals X of five spatially consecutive scanning lines.
_-2, X _-1, which Desa take X _0, X _1, X ₂ is input to the transversal filter 109 through 113. And these outputs Y
_-2 to Y ₂ are summed in the adder 114, the output signal is obtained.

Next, regarding the above-mentioned transversal filter,
The operation will be described with reference to FIG.

In the figure, 21 to 24 are unit delay lines, 25 to 29 are coefficient units, and 30 is an adder. In the figure, 21 to 24 represent unit delay lines, but specifically, it is appropriate to set the delay amount of 1/2 nf _h .

Each output from Xi and the unit delay lines 21 to 24
After passing through 29, it is added by the adder 30 and becomes the output signal Yi.

The spatiotemporal filter characteristic is determined by the value of the coefficient of this coefficient unit.

Next, FIG. 6 is a circuit system diagram showing the configuration of an embodiment of the receiving side according to the present invention.

In the figure, 31 is a YC separation circuit that separates a luminance signal and a chrominance signal, 32 is a space-time filter, 33 is a subtractor, 34 is a switch, and 35
Is a bandpass filter (BPF), 36 is an adder, 37 is a switch, 38 is a motion detection circuit, 39 is a phase inversion control signal generation circuit, 40 is a phase inversion circuit, and 41 is a color demodulator.

First, the input composite color television signal is separated into the luminance signal Y _L + Y _H ′ and the carrier color signal C by the YC separation circuit 31.

The luminance signal Y _L + Y _H ′ is supplied to the space-time filter 32 and the subtractor 33.
Added to. The spatiotemporal filter 32 extracts Y _H ′, adds it to the subtractor 33, and the subtracter 33 extracts Y _L.

On the other hand, the luminance signal component Y _H ′ from the spatio-temporal filter 32 is switched and sampled by the switch 34 at the cycle of the carrier wave nf _h ^* . This sampled signal contains Y _H ′
And Y _H are mixed and come out, but BPF 35 extracts only Y _H and adds it to the adder 36.

As described above with reference to FIG. 4, since the carrier wave nf _h ^* can be determined whether it is an even field or an odd field by the horizontal synchronizing signal HD and the vertical synchronizing signal VD, a control signal is generated from the HD and VD signals. It can be obtained by controlling the phase of nf _h by the circuit 39 and the phase inverting circuit 40.

In the adder 36 described above, the Y _H signal from the BPF 35 and the subtractor 33
And Y _L signal from been added, as a switching device 37, Y _L + Y _H
The broadband luminance signal of is extracted.

For the moving image, the switching device 37 is controlled by the control signal from the motion detecting circuit 38, and the input luminance signal is taken out as it is.

Further, the carrier color signal C from the YC separation circuit 31 is taken out as color difference signals I and Q by the color demodulator 41.

FIG. 7 is a frequency domain layout diagram showing another embodiment of the spectrum of the luminance signal according to the present invention. The figure shows n
= 520, which corresponds to nf _h ≈8.2 MHz. In this case, the folded high frequency luminance signal component Y _H ′ offset subsampled by nf _h ^* is located in the band of 2.2 to 4 MHz, and the low frequency luminance signal component Y _L is in the band of 0 to 2.2 MHz.
In the vertical direction, the entire band can be used for transmission. The vertical band that can be transmitted as the high-frequency luminance signal component Y _H ′ is also wider than in the case of FIG. Also,
The interference given to the current receiver is even smaller than in the case of FIG.

FIGS. 8 (A) and 8 (B) are system diagrams of circuits showing a configuration of an embodiment when digital processing is performed according to the present invention.

FIG. 8 (A) shows the structure of the transmitting side.

In the figure (A), 51 is an A / D converter, 52 is a Y _H ′ multiplex circuit, 53 is a D / D converter, 54 is an adder, 55 is a D / A converter, 56.5
7 is an A / D converter for the color difference signals I and Q, and 58 is a color modulator.

The operation will be described below with reference to FIG.

The input luminance signal Y is clock frequency 2 in the A / D converter 51.
A / D conversion is performed with nf _h .

This is because it is practically convenient to use this clock frequency in order to use the sampling signal nf _h ^* of the high-frequency luminance signal component Y _H.

The luminance signal Y A / D converted by the A / D converter 51 is a Y _H ′ multiplexing circuit.
The high frequency component Y _H of the luminance signal Y is converted to Y _H ′ and multiplexed.

The Y _H 'multiplexing circuit 52 can be realized in a manner similar to FIG. 4 described above configurations.

Signals are multiplexed 'Y _H by multiplexer 52' Y _H is applied to the D / D converter 53. In the D / D converter 53, the clock frequency is D / D converted from 2nf _h to 4f _SC .

Here, since the ratio of 2nf _h and 4f _SC is 8: 7, the D / D converter 53
Then, the input signal is converted from 8 samples to 7 samples of the output signal by interpolation.

The D / D conversion is performed here because the clock frequency of 4f _SC is convenient for processing the color signal of the television standard system.

Next, in the adder 54, the color difference signals I and Q are input to the A / D converter 5
The signals A / D converted by 6 and 57, respectively, and color-modulated by the color modulator 58, and the luminance signal D / D-converted by the D / D converter 53 described above are added to obtain Y _H ′. The carrier color signal is further multiplexed on the multiplexed luminance signal and applied to the D / A converter 55.

Then, D / A conversion is performed by the D / A converter 55 to obtain a composite color television signal.

Next, FIG. 8 (B) shows the configuration of the receiving side.

In the figure (B), 61 is an A / D converter, 62 is a YC separation circuit, 6
3 D / D converter, 64 Y _H separating circuit, 65 is a D / A converter, 66 a color demodulator, 67 and 68 is a D / A converter.

The operation will be described below with reference to FIG.

The composite color television signal that is input is the A / D converter 61.
And is A / D converted at a clock frequency of 4f _SC . Next, the YC separation circuit 62 separates the luminance signal and the color signal, and the luminance signal is added to the D / D converter 63.

In the D / D converter 63, the clock frequency is converted from 4f _SC to 2nf _h , that is, at a ratio of 7: 8. Then, the Y _H separation circuit 64
Then, Y _H is extracted from the multiplexed Y _H ′ component, and the luminance signal Y _L + Y _H combined with the low frequency component signal Y _L is extracted and added to the D / A converter 65. Next, the D / A converted luminance signal Y is obtained from the D / A converter 65.

On the other hand, the color signal separated by the YC separation circuit 62 described above is added to the color demodulator 64 and divided into two color difference signal components, and the D / A converters 67 and 68 respectively generate the color difference signals I and Q is taken out.

Although the above has described one embodiment of the configuration of the transmitting side and the receiving side according to the present invention, in addition to this configuration, for example, A / D conversion of the composite color television signal, or in the D / A conversion unit, the clock frequency To be 2nf _h . Then, on the transmission side, D / is output on the output side of the color modulator 58 in FIG. 8 (A).
The D conversion may be performed, and the receiving side may perform the D / D conversion on the input side of the color demodulator 66 in FIG. 8B.

However, the D / D conversion ratio in this case is 4f _SC and 2nf _h on the transmission side.
The ratio may be 7: 8, and vice versa on the receiving side.

EFFECTS OF THE INVENTION As is clear from the above, according to the present invention, the transmission standard of the current color television standard system is not changed.
And there is little interference to the current television receiver,
Furthermore, a high-definition television that retains a high resolution can be implemented for moving images as compared with conventional methods.

Furthermore, the present invention is applied to a color television standard system in Japan, and also to a color television system such as the NTSC system in the United States and the PAL system performed in Europe to obtain a high quality image. High-definition television can be implemented.

[Brief description of drawings]

FIG. 1 is an arrangement diagram of a frequency domain showing an embodiment of a spectrum of a luminance signal according to the present invention, FIG. 2 (A) is an explanatory diagram showing an example of a method of sampling a high frequency luminance component, and FIG. ) Is an explanatory diagram of the transmission region displayed in the three-dimensional spatial frequency region, FIG. 3 is a layout diagram of the transmission region shown in the three-dimensional space-time frequency region according to the embodiment of FIG. 1, and FIG. 4 is the present invention. FIG. 5 (A) is a circuit system diagram showing the configuration of an embodiment of the transmitting side according to FIG. 5, FIG. 5 (A) is a circuit system diagram showing the configuration of an embodiment of a space-time filter, and FIG. 5 (B) is FIG. 5 (A). FIG. 6 is a circuit system diagram showing the configuration of an embodiment of the transversal filter of FIG. 6, FIG. 6 is a circuit system diagram showing the configuration of an embodiment of the receiving side according to the present invention, and FIG. 7 is another spectrum of the luminance signal according to the present invention. FIG. 8 (A) is a layout diagram in the frequency domain showing an embodiment of the present invention. In the case of performing digital processing, circuit system diagram showing a configuration of an embodiment of the transmitting side, Figure 8 (B) is a circuit system diagram showing a reception-side structure corresponding to FIG. 8 (A). 1,32 …… Spatio-temporal filter, 2,5,34,37 …… Switcher, 3,38 …… Motion detection circuit, 4,35 …… Band filter (BPF), 6,10,30,36 , 54,103,114 …… Adder, 7,39 …… Control signal generation circuit, 8,40 …… Phase inversion circuit, 9,58 …… Color modulator, 10 …… Low-pass filter (LPF), 21,22 , 23,24 …… Unit delay line, 25,26,27,28,29 …… Coefficient unit, 31,62 …… YC separation circuit, 33 …… Subtractor, 41,66 …… Color subtone modulator, 51 , 56,57,61 …… A / D converter, 52 …… Y _H ′ multiple circuit, 53,63 …… D / D converter 55,65,67,68 …… D / A converter, 64… … Y _H separation circuit, 101,102 …… 1 field memory, 105,106,108 …… 1 line memory, 107 …… 1/2 line memory, 104 …… divider, 109,110,111,112,113 …… transversal filter.

Claims (3)

[Claims] 1. A television signal multiplex system in which a color difference signal is modulated with a subcarrier and multiplexed with a low frequency band luminance signal for transmission, in which a luminance signal of a color television is obliquely high in the horizontal-vertical spatial frequency range. Other than the spatio-temporal frequency domain, the high-frequency filtering means for filtering the high frequency band component of the luminance signal filtered by the spatio-temporal filtering means, and the high-frequency filtering means. Sampling means for sampling the high frequency band component signal of the luminance signal filtered by the means with a carrier having an integral multiple of the horizontal scanning frequency; and means for inverting the phase of the carrier with respect to the sampled carrier for each field cycle. A summing means for adding the signal sampled by the sampling means and the luminance signal filtered by the space-time filtering means. Television signal multiplexing method in which the butterflies. 2. A television signal multiplexing system in which a color difference signal is modulated with a subcarrier and multiplexed with a low frequency band luminance signal for transmission, in which a luminance signal of a color television is obliquely high in the horizontal-vertical spatial frequency range. Other than the spatio-temporal frequency domain, the spatio-temporal filtering means, high-frequency filtering means for filtering the high frequency band component of the luminance signal filtered by the spatio-temporal filtering means, and the high-frequency filtering Amplitude modulation means for amplitude-modulating the high frequency band component signal of the luminance signal filtered by the means with a carrier having an integral multiple of the horizontal scanning frequency, and the phase of the carrier is inverted with respect to the amplitude-modulated carrier for each field cycle And a summing means for summing the signal amplitude-modulated by the amplitude modulation means and the luminance signal filtered by the spatiotemporal filtering means. Signal multiplexing scheme. 3. A motion detecting means for detecting, for each pixel, whether or not an image is moving based on a luminance signal of the color television, and a still pixel based on an output of the motion detecting means. Switching means for selectively outputting the output signal of the luminance signal of the color television before inputting to the spatiotemporal filtering means in the moving pixel. The television signal multiplex system described in the paragraph.