JPH08298671A - Signal separation device - Google Patents

Abstract

(57) [Summary] [Object] To prevent a high-definition signal and a color signal from leaking each other in a high-definition television signal in which high-definition signals are multiplexed, and to obtain an image with little deterioration in image quality. In a signal separation circuit for separating a composite color television signal to obtain a luminance signal, a color signal and a high definition signal, the color signal extraction filter has a narrow pass band in the vertical frequency direction and the high definition signal extraction filter is vertical. The color signal and the high-definition signal are obtained by being configured to have a wide pass band in the frequency direction. The luminance signal extraction filter has a wide pass band in the vertical frequency direction and a narrow pass band in the time frequency direction, and extracts the luminance signal when the image is stationary. The extracted luminance signal is mixed with a component obtained by removing the color signal component and the high-definition signal component from the composite color television signal according to the amount of motion detected by the motion detection circuit, and an output luminance signal is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal separation device for television signals, and more particularly to a signal separation device suitable for television signals including high definition television signals compatible with current television signals.

[0002]

2. Description of the Related Art In recent years, a high definition television signal system (second generation EDTV system) which is completely compatible with the current broadcasting system NTSC system has been proposed. Second generation ED
In the TV system, the horizontal luminance signal is reinforced in order to improve the horizontal luminance resolution and increase the definition of the image. That is,
In the high definition television signal system, a frequency component higher than the transmission band (0 to 4.2 MHz) of the luminance signal, for example, 4.
The horizontal high-definition signal of 2 to about 6 MHz is frequency-converted (shifted) to transmit the high-definition television signal multiplexed in the transmission band. The high-definition information inserted in such a composite color television signal is one of the characteristics of the second-generation EDTV system, and hereinafter, the multiplexed horizontal high-definition signal is simply referred to as an HH signal.

FIGS. 13 (a) to 13 (c) are diagrams showing a three-dimensional frequency spectrum distribution of a high definition television signal in which HH signals are multiplexed. In FIGS. 13A to 13C, the μ axis indicates the horizontal frequency axis, the ν axis indicates the vertical frequency axis, the f axis indicates the time direction frequency axis, and Y indicates the luminance signal.
C represents a color signal. 13 (a) is a diagram of the three-dimensional frequency space seen from an oblique direction, FIG. 13 (b) is a projection diagram from the positive direction of the μ axis to the [f−ν] plane, and FIG. 13 (c).
Is a frequency distribution chart on the μ axis.

Generally, in a three-dimensional frequency space, the frequency spectra of the luminance signal, the color signal, and the HH signal are in the time direction when the motion of the image is large, and in the vertical direction and the horizontal direction when there is a fine pattern in the vertical direction. If there is a fine pattern on the side, it will spread horizontally. In FIG. 13 (b),
When the luminance signal, the color signal, and the HH signal spread in the time direction or the vertical direction, crosstalk between the signals may occur. Therefore, it is recommended that the Y signal, the C signal, and the HH signal be subjected to pre-combing on the transmission side, in which components interfering with each other are removed in advance.

In a device for receiving a high-definition television signal in which HH signals are multiplexed, in order to reproduce the signals,
The transmitted high-definition television signal is a Y signal, a C signal,
A signal separation device for separating the HH signal is required. As described above, since the Y signal, the C signal, and the HH signal are distributed on the [f-ν] plane as shown in FIG. 13B, in order to accurately separate the signals, the time domain or vertical A signal separating means by calculation in the area is adopted. As an example of this, Japanese Patent Laid-Open No. 06-038236 is disclosed.

FIG. 15 is a diagram showing the operation of the conventional signal separation device disclosed in Japanese Patent Laid-Open No. 06-038236. Each of FIGS. 15 (a1) to (c1) is a diagram showing a two-dimensional space-time composed of the y-axis and the t-axis, where the vertical direction of the screen is the y-axis and the time direction is the t-axis. ○ indicates that interlaced scanning is performed. 15 (a1) to (a3)
Is an operation for obtaining the Y signal, FIG. 15 (b1) to (b3)
Is an operation for obtaining a C signal, and FIG. 15C1 is an operation for obtaining an HH signal. Weighted addition is performed using the coefficients shown on the right of the black circles to obtain Y, HH, and C signal components.

FIG. 19 is a block diagram showing a configuration of a conventional signal separation device. In the figure, an input composite color television signal 101 is composed of 262 line delay circuits 1 and 8, 1.
The line delay circuits 2 and 4 and 5 and 7 and the 261 line delay circuits 3 and 6 delay a maximum of 1050 lines. With respect to the delayed signal and the input signal 101, the motion of the image is detected by the motion detection circuit 12 by the correlation between the sample points separated by one frame or two frames. In addition, the Y extraction circuit 3
7, C extraction circuit 38, and HH extraction circuit 39.
The weighted addition shown in (a1) to (c1) is performed.

FIG. 20 is a block diagram showing the configuration of the Y extraction circuit 37 in the conventional signal separation circuit. In the figure, a first Y extraction filter 40 is a filter performing the operation of FIG. 15 (a1), a second Y extraction filter 41 is a filter performing the operation of FIG. 15 (a2), and a third Y extraction filter 42. Is a filter that performs the operation of FIG.

FIG. 21 is a block diagram showing the structure of a C extraction circuit 38 in a conventional signal separation circuit. In the figure, a first C extraction filter 44 is a filter that performs the operation of FIG. 15 (b1), a second C extraction filter 45 is a filter that performs the operation of FIG. 15 (b2), and a third C extraction filter 46. Is a filter that performs the operation of FIG.

FIG. 22 shows HH in the conventional signal separation circuit.
It is a block diagram showing a configuration of an extraction circuit 39. The HH extraction filter 48 is a filter that performs the operation of FIG.

FIGS. 16A and 16B are characteristic diagrams on the [f-ν] plane of the Y signal extracted by the first Y extraction filter 40, which are obtained by the operation of FIG. 15 (a1). To be 17A to 17C show the first C extraction filter 4
It is a characteristic on the [f-ν] plane of the C signal extracted by 4 and is obtained by the operation of FIG. 15 (b1). FIG.
15A to 15C are characteristics on the [f-ν] plane of the HH signal extracted by the HH extraction filter 48, and FIG.
It is obtained by the operation of (c1).

According to FIGS. 16 to 18, when the first Y extraction filter 40, the first C extraction filter 44, and the HH extraction filter 48 are used, the time frequency pass band is narrow and the vertical frequency pass band is wide. Therefore, it is suitable for signal separation of still images. On the other hand, the third Y extraction filter 42, the third C
The extraction filter 46 has a wide time-frequency pass band and a narrow vertical frequency pass band (not shown), and is therefore suitable for video signal separation. In addition, the second Y extraction filter 4
The first and second C extraction filters 45 have intermediate characteristics. Therefore, the outputs of the Y extraction filters 40 to 42, the C extraction filters 44 to 46, and the HH extraction filter 48 are mixed and controlled by the output 105 of the motion detection circuit 12, and the Y signal 102 and the C signal 103 suitable for the motion of the image. , HH signal 104 is obtained.

On the other hand, the amount of motion detected by the motion detecting circuit 12 is represented by a motion coefficient signal in the form of, for example, a motion coefficient k (0≤k≤1), and for example, the image is determined to be a complete still image. In this case, the motion coefficient signal is controlled such that k = 0, and when the image is determined to be a complete moving image, k = 1.

Generally, when the image is an image with a small amount of motion such as a still image (0≤k <α, where 0 <α <1), the mixing circuit 43 of the Y extraction circuit shown in FIG.
The Y extraction filters 40 to 42 are controlled to increase the mixing ratio of the outputs of the first Y extraction filter 40 and decrease the mixing ratio of the outputs of the second and third Y extraction filters 41 and 42.

When the amount of motion of the image is moderate (α≤k
≦ β, where 0 <α <β <1), the mixing circuit 43 increases the mixing ratio of the outputs of the second Y extraction filter 41 and outputs the outputs of the first and third Y extraction filters 40 and 42. The mixing ratio is controlled to be small.

When the amount of movement of the image is large (β <k ≦ 1)
In the mixing circuit 43, the third Y extraction filter 4
It is controlled so that the mixing ratio of the outputs of the second Y extraction filters 40 and 41 is increased, and the mixing ratio of the outputs of the first and second Y extraction filters 40 and 41 is decreased.

Also in the mixing circuit 47 of the C extraction circuit shown in FIG. 21, similarly, the mixing ratio of the outputs of the C extraction filters 44 to 46 is controlled by the amount of movement of the image, and the C signal is extracted. In the HH extraction circuit shown in FIG. 22, the output of the HH extraction filter 48 is multiplied by (1-k) by the multiplication circuit 16 and the conversion circuit 17 so that the HH is obtained only when the amount of motion of the image is small.
The signal 104 is output.

That is, when the amount of motion of the image is small, the motion signal 105 is shown in FIGS. 15 (a1), (b1), and (c1).
When the Y signal, the C signal, and the HH signal are extracted by the calculation shown in FIG.
By the calculations shown in (a2) and (b2), the Y signal,
When the C signal is extracted and the amount of motion is large, FIG.
3), each signal extraction circuit is controlled so as to extract the Y signal and the C signal by the operations shown in (b3).

[0019]

14 (a) to 14 (c).
FIG. 4 is a spectrum distribution diagram of Y signal, C signal, and HH signal when an image is stationary in a three-dimensional frequency space. In the figure, when Y, HH, and C have vertical frequency high-frequency components,
The frequency spectrum has a spread in the vertical frequency direction. In the signal separation circuit of the conventional example, the frequency domain shown in FIGS. 17A to 17C is extracted as C, and the frequency domain shown in FIGS.
The frequency region shown in (c) is extracted as HH. FIG. 17
According to (b), at f = 15 Hz, 0 cph, 5
The gain is halved near 25/2 cph. On the other hand, if the HH signal is spread in the vertical frequency direction, f
= 15 Hz, as shown in FIG.
There is HH up to around 0 cph around 25/4 cph, and a maximum of about 1/2 of such HH component is demodulated as C. Similarly, according to FIG.
C having a spread in the vertical frequency direction is reproduced as HH.

When the C signal and the HH signal spread in the vertical frequency direction as described above, there is a problem that components that cannot be removed by the filter leak into each other and crosstalk occurs.

The present invention has been made in order to solve the above-mentioned problems, and has a C signal having a wide vertical frequency component, HH.
The purpose is to separate signals without crosstalk.
That is, it is an object of the present invention to obtain a signal separation device capable of accurately performing signal separation when HH signals are multiplexed and reproducing a clear image with little deterioration in image quality.

[0022]

A signal separating apparatus according to a first aspect of the present invention is a signal for separating a luminance signal, a color signal and an HH signal from a composite color television signal in which a horizontal high definition signal is multiplexed. In the separation device, an identification control signal for identifying information regarding an input signal, which is an identification control signal decoding means for decoding a signal which is multiplexed and transmitted with a composite color television signal, and a plurality of a plurality of fields having a time difference of at most 4 fields. A color signal having frequency components in the second and fourth quadrants in the time-vertical frequency space is extracted by a calculation between fields of a composite color television signal to extract a color signal having a wide pass band in the time-frequency direction and a narrow width in the vertical frequency direction. Between the color signal extraction means for extracting with a filter and the fields of a plurality of composite color television signals having a time difference of up to 4 fields HH signal extraction means for extracting, by calculation, an HH signal having frequency components in the first and third quadrants in the time-vertical frequency space with an HH signal extraction filter having a narrow pass band in the time frequency direction and a wide pass band in the vertical frequency direction. And a luminance signal extraction filter that performs calculation between frames of a plurality of composite color television signals having a time difference of up to 4 fields, or a subtraction circuit that subtracts a color signal and an HH signal from the composite color television signal,
A luminance signal extracting means for obtaining a luminance signal, and a motion detecting means for detecting a motion amount of the composite color television signal and controlling outputs of the luminance signal extracting means and the HH signal extracting means are provided.

A signal separation device according to claim 2 of the present invention is
In the color signal extraction means according to claim 1, the color signal extraction filter suppresses the gain of the signal component existing in the first and third quadrants in the time-vertical frequency space to at most 30%.

The signal separating apparatus according to claim 3 of the present invention is
In the HH signal extraction means according to claim 1, the HH signal extraction filter suppresses the gain of the signal component existing in the second and fourth quadrants in the time-vertical frequency space to at most 30%.

A signal separating apparatus according to claim 4 of the present invention is
The signal processing apparatus according to claim 1, further comprising vertical edge detecting means for detecting a vertical frequency high frequency component of the image, and when the vertical edge detecting means detects a vertical high frequency component, a color signal extraction filter. The color signal extracting means and the HH signal extracting means are controlled so that the vertical pass band of the HH signal extraction filter is narrowed and the vertical pass band of the HH signal extraction filter is narrowed.

A signal separating apparatus according to claim 5 of the present invention is
When the identification control signal decoding means according to claim 1 determines that the HH signal is not multiplexed in the input signal,
Color signal extraction means for obtaining a color signal by any one of a plurality of color signal extraction filters for performing inter-frame, inter-field, and intra-field operations of a plurality of composite color television signals having a time difference of up to 4 fields, and the composite. A motion detection unit that detects the amount of motion of a color television signal and switches the characteristics of the color signal extraction filter, and the output of the color signal extraction unit is subtracted from the composite color television signal to generate an output luminance signal. A signal is separated by a subtractor.

A signal separation device according to claim 6 of the present invention is
The discrimination control signal decoding means according to claim 1 does not control the output of the HH signal extraction filter based on the output result of the motion detecting means when it is determined that the input signal is precombed. .

[0028]

In the signal separating apparatus according to the first aspect of the present invention, the HH signal extraction means and the C signal extraction means extract the HH signal extraction filter and the C signal extraction of the composite color television signal in which the HH signals are multiplexed. Since the overlapping of the extraction areas of the filters is reduced, it is possible to reduce the image quality deterioration due to the crosstalk between the HH signal and the C signal.

In the signal separating apparatus according to the second aspect of the present invention, the C signal extracting means has a sharp cutoff characteristic of the C signal extracting filter for obtaining the C signal from the composite color television signal in which the HH signals are multiplexed. Then, the amount of the HH signal entering the pass band of the C signal extraction filter is reduced, so that the image quality deterioration due to the HH signal leaking into the C signal band can be reduced.

In the signal separating apparatus according to the third aspect of the present invention, the HH signal extracting means obtains the HH signal from the composite color television signal in which the HH signal is multiplexed.
Since the cutoff characteristic of the H signal extraction filter is made steep to reduce the amount of the C signal entering the pass band of the HH signal extraction filter, it is possible to reduce the image quality deterioration due to the C signal leaking into the HH signal band. .

In the signal separation device according to the fourth aspect of the present invention, the vertical edge detection circuit is the vertical edge component of the Y signal due to the vertical edge component of the composite color television signal in which the HH signals are multiplexed. If it is determined that the HH signal and the C signal are extracted, the HH signal and the C signal are extracted.
The pass band of the signal extraction filter is narrowed in the vertical frequency direction,
Since the pass band of the C signal extraction filter is widened in the vertical frequency direction, it is possible to reduce image quality deterioration due to the C signal leaking into the HH signal band.

In the signal separating apparatus according to the fifth aspect of the present invention, the signal separating circuit extracts the HH signal when it is determined by the output of the identification control signal decoding circuit that the HH signal is not multiplexed. Since the C signal is extracted by adaptively switching the calculation between the frames, between the fields, and within the field without performing it, the C signal can be reproduced accurately.

In the signal separating apparatus according to the sixth aspect of the present invention, the signal separating circuit moves when the input signal is judged to have been precombed by the output of the discrimination control signal decoding circuit. Since the HH signal is reproduced regardless of the detection result, it is not affected by the accuracy of motion detection.

[0034]

【Example】

Example 1. FIG. 1 is a diagram showing the operation of the signal separation circuit according to the first embodiment of the present invention. In the figure, (a) shows an operation for extracting the Y signal when the image is stationary, (b) shows an operation for extracting the C signal, and (c) shows an operation for extracting the HH signal. The frequency bands of the C signal and the HH signal extracted by the operations shown in FIGS. 1B and 1C are shown in FIGS. 4 and 5, respectively. As shown in FIGS. 4B and 4C, the gain of the C signal extraction filter that performs this operation in the region where the HH signal exists is 20% or less at the maximum. Further, from FIGS. 5B and 5C, H
The maximum gain of the H signal extraction filter in the region where the C signal exists is 30% or less. Further, since the filter coefficients shown in FIGS. 1B and 1C can be realized by multiplying the bit shift of the signal and the addition result thereof by a certain value, the circuit scale can be suppressed.

1 (b) and 1 (c), calculation on the vertical-time plane is performed, and a horizontal band pass filter (hereinafter BP) is used.
Since the band is limited in F), the band is also limited in the μ-axis direction. Since the operation of extracting the Y signal when the image is stationary is the same as that of the conventional example shown in FIG. 15 (a1), its pass band is shown in FIGS. 16 (a) and 16 (b).

In general, the effect of the HH signal appears remarkably when the image is stationary, and is inconspicuous when the image is moving. Therefore, HH
The pass band in the time-frequency direction of the signal extraction filter is narrowed. On the other hand, since the C signal is indispensable for image reproduction regardless of whether it is a still image or a moving image, the pass band is widened in the time-frequency direction. That is, the characteristics of the pass band of the filter are changed depending on whether it is the HH signal or the C signal, and the signal separation is performed while suppressing the amount of the HH and C components spread in the vertical direction leaking into the mutual regions.

FIG. 8 is a block diagram showing a configuration example of the signal separation circuit of the first embodiment. In the figure, the Y extraction filter 9
Is a filter that performs the operation of FIG.
Reference numeral 0 is a filter that performs the operation of FIG. 1B, and HH extraction filter 11 is a filter that performs the operation of FIG.

C extraction filter 10 and HH extraction filter 1
The C signal 103 and the HH signal 104 obtained by 1 are added by the adding circuit 15 and then subtracted from the input composite color television signal 101 by the subtracting circuit 13 to obtain C
And the components excluding HH are obtained.

The output of the subtraction circuit 13 and the output of the Y extraction filter 9 are input to the mixing circuit 14, and the output 105 of the motion detection circuit 12 causes the calculation by the following equation (1) to perform mixing control. It

Y = k · Ym + (1−k) · Ys (1) where, k: motion coefficient Ym: output value of subtraction circuit 13, Ys: output value of Y extraction filter 9.

That is, when the image is a still image, the output of the Y extraction filter 9 is controlled, and when the image is a moving image, the output of the subtraction circuit 13 is controlled to be increased.

Example 2. FIG. 2 is a diagram showing the operation of the signal separation circuit according to the second embodiment of the present invention. In the figure, the difference from FIG. 1 is that the C signal extraction filter and H
The point is that two types of H signal extraction filters are provided, a vertical edge detection circuit is further provided, and a suitable filter is selected from the two types of filters according to the edge detection result.

In FIG. 2, (b1) and (b2) are operations for extracting the C signal. 2 (b1) is shown in FIG.
It is the same as FIG. 4B, and its frequency characteristic is shown in FIG.
It is represented by (c). The frequency characteristic of FIG. 2 (b2) is shown in FIG.
4 (a) to 4 (c), the pass characteristics in the vertical direction are wider than those in FIGS. 4 (a) to 4 (c).

2 (c1) and 2 (c2) show the operation for extracting the HH signal. 2 (c1) is shown in FIG.
It is the same as (c), and its frequency characteristic is shown in FIG.
It is represented by (c). The frequency characteristic of FIG. 2 (c2) is shown in FIG.
5A to 5C, the pass characteristics in the vertical direction are narrower than those of FIGS. 5A to 5C.

Generally, the correlation between the Y signal and the C signal is strong, and
If the signal contains vertical edge components, the C signal is also often a vertical edge. Therefore, when an edge component is detected in the Y signal, the pass band of the C signal is widened in the vertical direction and the pass band of the HH signal is narrowed in the vertical direction, so that the vertical frequency high-frequency component of the C signal leaks into the HH signal. Prevent.

FIG. 9 is a block diagram showing the configuration of the signal separation circuit of the second embodiment. In the figure, the first C extraction filter 10 is a filter that performs the operation of FIG.
The extraction filter 18 performs the operation of FIG. 2 (b2), the first HH extraction filter 11 performs the operation of FIG. 2 (c1), and the second HH extraction filter 19 of FIG.
It is a filter that performs the operation of (c2).

The two C signals obtained by the C extraction filters 10 and 18 are input to the mixing circuit 21 and the output 106 of the vertical edge detection circuit 20 is used to obtain the following equation (2).
Then, the mixture is controlled.

C = h · Cb + (1−h) · Cn (2) where, h: vertical edge coefficient Cb: output value of C extraction filter 18, Cn: output value of C extraction filter 10.

That is, when the Y signal is not a vertical edge component, the output of the first C extraction filter 10 has a narrow pass band in the vertical frequency direction, and when it is a vertical edge component, the pass band in the vertical frequency direction is Wide second C extraction filter 1
It is controlled to increase the ratio of the eight outputs.

Similarly, the two HH signals obtained by the HH extraction filters 11 and 19 are input to the mixing circuit 22, and the output 106 of the vertical edge detection circuit 20 performs the calculation by the following equation (3). In addition, the mixing is controlled.

HH = hHn + (1-h) Hb (3) Here, Hn is the output value of the HH extraction filter 19 and Hb is the output value of the HH extraction filter 11.

That is, when Y is not a vertical edge component, the output of the first HH extraction filter 11 has a wide pass band in the vertical frequency direction, and when Y is a vertical edge component, the pass band in the vertical frequency direction is narrow. It is controlled to increase the ratio of the output of the second HH extraction filter 19.

FIG. 10 is a block diagram showing the configuration of the vertical edge detection circuit in the signal separation circuit of the second embodiment. In the figure, the vertical edge detection circuit includes 26 in FIG.
The outputs of the 1-line delay circuit 3 and the 1-line delay circuits 4 and 5 are input, and these signals are signals of three continuous scanning lines. The coefficient circuits 23 to 25 and the adder circuit 26 perform an operation between lines to obtain a vertical frequency high frequency component. Furthermore, by the low pass filter (LPF) 27,
After passing only the horizontal frequency low-frequency component, it is converted into an absolute value by the absolute value circuit 28, and the vertical edge component 1 of the Y signal
I get 06.

In the present embodiment, signal separation is performed by two types of C extraction filters and HH extraction filters, but a vertical edge detection circuit is used by using two or more types of C extraction filters and HH extraction filters. It is also possible to adopt a configuration in which finer switching of the filters is performed by the output of.

Example 3. FIG. 3 is a diagram showing the operation of the signal separation circuit according to the third embodiment of the present invention. In the figure, the difference from FIG. 1 is that the input composite color television signal 10
When the HH signal is not multiplexed with 1, the HH signal is not reproduced and the YC separation characteristic is switched according to the motion. 3, (b1) to (b3) are filters for extracting the C signal, and (b1) is a filter shown in FIG.
It is a filter equivalent to (b) and FIG. 2 (b1). (B
2) is a filter for extracting a C signal particularly suitable for a still image, and (b3) is a filter for extracting a C signal particularly suitable for a moving image.

Whether or not the HH signal is multiplexed with the input signal is determined by the information on the identification control signal transmitted using the scanning line at the uppermost end of the screen of each field of the composite color television signal. .

FIG. 11 is a block diagram showing the configuration of the signal separation circuit of the third embodiment. In the figure, the C signal extraction filter 10 performs the operation of FIG. 3 (b1), the frame comb filter 29 performs the operation of FIG. 3 (b2), and the intra-field filter 30 performs the operation of FIG. 3 (b3). It is a filter to do. By the output of the motion detection circuit 12,
If it is a completely still image, the frame comb filter 29, if it is a completely moving image, the in-field filter 30, and otherwise, the mixing circuit 32 so that the C signal is extracted by the C signal extraction filter 10. Is mixed and controlled.

The identification control signal is the identification control signal decoding circuit 3
5, the result is input to the switch circuit 34, and when the HH signal is not multiplexed, the signal extracted by the HH signal extraction filter 11 is turned off, and HH signal is extracted.
Do not output the signal.

Further, the output of the identification control signal decoding circuit 35 is input to the selection circuit 33, and when the HH signal is not multiplexed, the output of the mixing circuit 32 is selected, and when the HH signal is multiplexed. 8, the selection circuit 33 is controlled so that the output of the C signal extraction filter 10 is output as the C signal.

Similarly, the output of the identification control signal decoding circuit 35 controls the selection circuit 31. When the HH signal is not multiplexed, the input decoded color television signal 101 outputs C.
When the output of the subtraction circuit 13 for subtracting the signal is selected and the HH signal is multiplexed, the mixing circuit 14 is used as in FIG.
So that the output of the selection circuit 31 is output as the Y signal.
Control.

Example 4. FIG. 12 is a block diagram showing the configuration of the signal separation circuit according to the fourth embodiment of the present invention. In the figure, the difference from FIG. 8 is that when the input composite color television signal 101 is precombed, the signal obtained by the HH signal extraction filter 11 is
It is a point to be reproduced regardless of the motion detection result.

On the transmission side, when precombing is performed, Y, C, and HH are band-limited and multiplexed so as to fit in each signal band of the frequency distribution chart shown in FIG. 13B. Therefore, signals other than the HH signal do not leak into the HH signal multiplex area of FIG.
Even if the output of the HH extraction filter is always reproduced as an HH signal, interference due to crosstalk does not occur. Since the identification control signal also includes information for determining whether or not precombing is performed on the transmission side, this identification control signal switches whether to control the output of the HH signal extraction filter. be able to.

In FIG. 12, the identification control signal decoding circuit 3
Reference numeral 5 decodes the identification control signal, inputs it to the selection circuit 36, selects the output of the HH extraction filter 11 when precombing is performed, and selects it when precombing is not performed. Similar to FIG. 8, the selection circuit 36 is controlled so that the output of the multiplication circuit 16 is output as the HH signal.

[0064]

According to the signal separating apparatus of the first aspect of the present invention, the HH signal and the C signal are extracted by the band pass filter which matches the signal characteristics of the HH signal and the C signal. , HH signals are reproduced as C signals, or C signals are reproduced as HH signals, and as a result, crosstalk can be reduced.

According to the signal separating apparatus of the second aspect of the present invention, since the C signal is extracted by the band pass filter which matches the signal characteristic of the C signal, the HH signal leaking into the C signal band. Can be prevented from being reproduced as a C signal, and as a result, crosstalk can be reduced.

According to the signal separating apparatus of the third aspect of the present invention, since the HH signal is extracted by the band pass filter which matches the signal characteristic of the HH signal, the C signal leaking into the HH signal band. Is reproduced as an HH signal,
As a result, crosstalk can be reduced.

According to the fourth aspect of the signal separating apparatus of the present invention, the signal extraction is performed by switching the vertical pass bands of the C extraction filter and the HH extraction filter depending on whether or not the Y signal includes a vertical edge component. Since it does, C depending on the design
It is possible to reduce crosstalk in which the vertical frequency high-frequency component of the signal leaks into the HH signal.

According to the signal separating apparatus of the fifth aspect of the present invention, the signal separating method is switched depending on whether or not the HH signal is multiplexed, and when the HH signal is not multiplexed, the HH signal is extracted. Since the input signal is YC separated according to the movement without performing the above, it is possible to perform signal separation suitable for the transmission signal.

According to the sixth aspect of the signal separating apparatus of the present invention, the output of the HH signal extraction filter is switched depending on whether or not the pre-combing process is performed. Even if there is an error in the motion detection, it does not depend on the error.

[Brief description of drawings]

FIG. 1 is a diagram showing an operation of a signal separation circuit according to a first embodiment of the present invention.

FIG. 2 is a diagram showing an operation of a signal separation circuit according to a second embodiment of the present invention.

FIG. 3 is a diagram showing an operation of a signal separation circuit according to a third embodiment of the present invention.

FIG. 4 is a diagram showing the characteristics of the color signal extraction filters of Examples 1 to 4.

FIG. 5 is a diagram showing characteristics of the high-definition signal extraction filters of Examples 1 to 4.

FIG. 6 is a diagram showing characteristics of a color signal extraction filter according to the second embodiment.

FIG. 7 is a diagram showing characteristics of a high definition signal extraction filter according to the second embodiment.

FIG. 8 is a block diagram illustrating a configuration of a signal separation circuit according to the first exemplary embodiment.

FIG. 9 is a block diagram illustrating a configuration of a signal separation circuit according to a second exemplary embodiment.

FIG. 10 is a block diagram showing a configuration of a vertical edge detection circuit in the signal separation circuit according to the second embodiment.

FIG. 11 is a block diagram showing a configuration of a signal separation circuit according to a third embodiment.

FIG. 12 is a block diagram showing a configuration of a signal separation circuit according to a fourth embodiment.

FIG. 13 is a three-dimensional frequency spectrum distribution map of a high-definition television signal in which HH signals are multiplexed,
(A) is a view seen from an oblique direction, (b) is a view seen from the positive direction of the μ axis, and (c) is a projection view onto the μ axis.

FIG. 14: Y signal and C in three-dimensional frequency space
(A) is a view of the spectrum distribution of the signal and the HH signal seen from an oblique direction, (b) is a view of the μ-axis seen from the positive direction,
(C) is a projection view on the μ axis.

FIG. 15 is a diagram showing an operation of a conventional signal separation circuit.

FIG. 16 is a diagram showing characteristics of a conventional luminance signal extraction filter.

FIG. 17 is a diagram showing characteristics of a conventional color signal extraction filter.

FIG. 18 is a diagram showing characteristics of a conventional high definition signal extraction filter.

FIG. 19 is a block diagram showing a configuration of a conventional signal separation circuit.

FIG. 20 is a Y extraction circuit 3 in a conventional signal separation circuit.
7 is a block diagram showing the configuration of No. 7.

FIG. 21 is a C extraction circuit 3 in a conventional signal separation circuit.
8 is a block diagram showing a configuration of No. 8.

FIG. 22 is a block diagram showing a configuration of an HH signal extraction circuit 39 in a conventional signal separation circuit.

[Explanation of symbols]

1,8 262 line delay circuit, 2,4,5,7 1 line delay circuit, 3,6261 line delay circuit, 9,40
-42 Y signal extraction filter 10, 18, 44-46
C signal extraction filter, 11, 19, 48 HH signal extraction filter, 12 motion detection circuit, 13 subtraction circuit, 1
4, 21, 22, 32, 43, 47 mixing circuit, 15 addition circuit, 16 multiplication circuit, 17 conversion circuit, 20 vertical edge detection circuit, 23, 24, 25 coefficient circuit, 27
LPF, 28 absolute value circuit, 29 frame comb filter, 30 field band pass filter, 34 switch circuit, 31, 33, 36 selection circuit, 35 identification control signal decoding circuit, 37 Y signal extraction circuit, 38 C signal extraction circuit , 39 HH signal extraction circuit, 101 input composite color television signal, 102 output luminance signal, 103
Output color signal, 104 output high definition signal, 105 motion signal, 106 vertical edge signal.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoichi Asamoto No. 1 Nagaokakyo Baba Institute, Kyoto Works Mitsubishi Electric Co., Ltd. (72) Inventor Masaki Yamakawa No. 1 Nagaokakyo Baba Institute Kyoto, Mitsubishi Electric Corporation Inside the factory

Claims (6)

[Claims] 1. A signal separation device for separating a luminance signal, a color signal and an HH signal from a composite color television signal (high definition television signal) in which a horizontal high definition signal (hereinafter referred to as an HH signal) is multiplexed. , An identification control signal for identifying information relating to an input signal, the identification control signal decoding means for decoding a signal multiplexed and transmitted with a composite color television signal, and a plurality of composite color televisions having a time difference of up to 4 fields. By the calculation between the fields of the John signal, the color signal having the frequency components of the second and fourth quadrants in the time-vertical frequency space is extracted by the color signal extraction filter whose pass band is wide in the time frequency direction and narrow in the vertical frequency direction. The color signal extraction means for extracting and the performance between fields of a plurality of composite color television signals having a time difference of up to 4 fields. HH signal extraction means for extracting an HH signal having frequency components in the first and third quadrants in the time-vertical frequency space by a HH signal extraction filter having a narrow pass band in the time frequency direction and a wide width in the vertical frequency direction. And a luminance signal extraction filter that performs calculation between frames of a plurality of composite color television signals having a time difference of up to 4 fields, or a subtraction circuit that subtracts a color signal and an HH signal from the composite color television signal,
It is characterized by comprising: a luminance signal extracting means for obtaining a luminance signal; and a motion detecting means for detecting a motion amount of the composite color television signal and controlling outputs of the luminance signal extracting means and the HH signal extracting means. Signal separation device. 2. The color signal extraction means in the color signal extraction means is characterized in that the gain of the signal component existing in the first and third quadrants in the time-vertical frequency space is suppressed to at most 30%. Item 1. The signal separation device according to item 1. 3. The HH signal extraction means, wherein the HH signal extraction filter suppresses the gain of the signal components existing in the second and fourth quadrants in the time-vertical frequency space to at most 30%. Item 1. The signal separation device according to item 1. 4. The signal separating device further comprises vertical edge detecting means for detecting a vertical frequency high frequency component of the image, and when the vertical edge detecting means detects a vertical high frequency component, a color signal extraction filter. 2. The signal separation device according to claim 1, wherein the color signal extraction means and the HH signal extraction means are controlled so that the vertical pass band of the HH signal extraction filter is widened and the vertical pass band of the HH signal extraction filter is narrowed. 5. When the identification control signal decoding means determines that the HH signal is not multiplexed in the input signal,
Color signal extraction means for obtaining a color signal by any one of a plurality of color signal extraction filters for performing inter-frame, inter-field, and intra-field operations of a plurality of composite color television signals having a time difference of up to 4 fields, and the composite. A motion detection unit that detects the amount of motion of a color television signal and switches the characteristics of the color signal extraction filter, and the output of the color signal extraction unit is subtracted from the composite color television signal to generate an output luminance signal. The signal separation device according to claim 1, wherein the signal separation is performed by a subtractor. 6. The identification control signal decoding means does not control the output of the HH signal extraction filter based on the output result of the motion detection means when it is determined that the input signal is precombed. The signal separation device according to claim 1.