JPH07123370A - Muse signal decoder - Google Patents

Abstract

PURPOSE:To eliminate the return of an unnecessary frequency component to a low band generated in conventional sampling frequency conversion, to accurately reproduce still pictures in an inter-field interpolation processing and to improve picture quality by providing a sampling frequency conversion circuit provided with a low-pass filter having a cut-off frequency within the range of a specific value frequency. CONSTITUTION:Other than a filter 203 having the impulse response of a General Post Office ministral ordinance number 16 attached list number 5, the low-pass filter 204 having the cut-off frequency in the range from 12.15MHz to 16.2MHz is provided, and the signals inter-frame interpolated in a MUSE decoding processing are processed by the filter 203 and the low-pass filter 204 in the sampling frequency conversion circuit 200. Thus, the return of the unnecessary frequency component to the low band generated in the conventional sampling frequency conversion circuit can be eliminated, the still pictures can be accurately reproduced in the inter-field interpolation processing following the sampling frequency circuit 200 and the picture quality is improved.

Description

Detailed Description of the Invention

[0001]

[Table of Contents] The present invention will be described in the following order. Industrial Application Conventional Technology (FIGS. 4 to 9) Problems to be Solved by the Invention (FIGS. 4 to 10) Means for Solving the Problems (FIGS. 1 to 3) Actions (FIGS. 1 to 3) ) Example (FIGS. 1-6) Effect of the invention

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a MUSE signal decoding apparatus, and is particularly suitable for being applied to an apparatus for inter-field interpolation processing by generating inter-field interpolation signals from inter-frame interpolation signals.

[0003]

2. Description of the Related Art At present, television-vision broadcasting by a high-vision system using satellite broadcasting is put into practical use. The frequency band of a broadcasting signal transmitted by this high-vision system is about 2 channels of the satellite broadcasting by the conventional system. Minutes are required, so MUSE (multiplue sub-nyquist sump
ling encoding) band compression by the analog transmission system is compressed and transmitted. In this MUSE system, a video signal is subsampled twice at different frequencies, and image data is compressed and transmitted. Also M
In the USE method, the video signal in the still image area is processed differently from the video signal in the moving area to obtain a high-quality image.

A transmission signal (MUS
The MUSE decoder for decoding the E signal) is configured as shown in FIG. That is, the MUSE signal is input to the analog digital (A / D) converter 1 and the MUS
The E analog signal is A / D converted into a digital signal of 16.2 [M samples / sec] and then supplied to the transmission system processing circuit 2 and the control code demodulation circuit 3. The control code demodulation circuit 3 demodulates a control code such as a motion vector and sends it to a predetermined circuit.

The transmission system processing circuit 2 subjects the input digital signal (data) to processing such as de-emphasis and inverse gamma correction for the transmission path, and then the luminance signal processing circuit 4, the chroma signal processing circuit 11 and the motion detection. Output to the circuit 12.
Of these, in the luminance signal processing circuit 4, 16.2 [M samples /
Second], the luminance signal sub-sampling data is separated from the input digital signal, and the inter-frame interpolation circuit 5 performs inter-frame interpolation processing on the luminance signal sub-sampling data in the still image area. Second], the sampling frequency conversion circuit 6
The data of 24.3 [Msample / sec] is reproduced from the data of 2.4 [Msample / sec]. Further, the inter-field interpolating circuit 7 obtains this signal from the data of 24.3 [M samples / sec] to obtain the luminance signal data of the still image region of 48.6 [M samples / sec].

On the other hand, field interpolation processing is performed on the luminance signal sub-sampling data in the moving image area by the field interpolation circuit 8 to obtain data of 32.4 [M samples / second], and then the sampling frequency conversion circuit. By 9
Sampling frequency conversion is performed on the signal data of 32.4 [M samples / sec] to the data signal of 48.6 [M samples / sec] to obtain the luminance signal data of the moving image area. Here, the interpolation means inserting a predetermined sampling value at a position where no sampling value exists.

The luminance signal of the still picture area and the luminance signal of the moving picture area thus processed are mixed at a predetermined ratio in the MIX processing circuit 10 and output as a decoded luminance signal. In order to determine the mixing ratio, the motion detection circuit 12 detects a motion amount from the input signal, generates a control signal designating the mixing ratio, and supplies the control signal to the luminance signal processing circuit 4.

The chroma signal processing circuit 11 separates the color signal (chroma signal) sub-sampling data from the input signal,
The same processing as the processing for the luminance signal sub-sampling data in the luminance signal processing circuit 4 is performed on the color signal sub-sampling data. Therefore, the chroma signal processing circuit 11 is also supplied from the motion detection circuit 12 with a control signal for designating the mixing ratio of the color signal of the still image area and the moving image area. The chroma signal processing circuit 11 uses the color difference signal R
-Y, BY are generated.

The luminance signal generated by the luminance signal processing circuit 4 and the color difference signal R- generated by the chroma signal processing circuit 11
Y and B-Y are subjected to the time axis extension operation at a ratio of 11 to 12 in the time axis extension circuits 13, 14 and 15, and finally,
The signal data of 44.55 [M samples / sec] is obtained. The luminance signal and the color difference signals R-Y and B-Y which have been expanded in the time axis are converted into color signals R, G and B by the inverse matrix circuit 16. Furthermore, the R, G, and B signals are gamma correction circuits 17, 18, and 1.
After being gamma-corrected by 9, the analog-to-digital (D / A) converters 20, 21 and 22 perform D / A conversion and supplied to a CRT device (not shown).

In the MUSE decoder as described above, the sampling frequency conversion processing in the luminance signal still image area in the conventional sampling frequency conversion circuit 6 is 32.4 [M samples / sec] input to the sampling frequency conversion circuit 6.
The digital signal of the
After performing the conversion operation to double the time to 97.2 [M samples / sec],
After passing through the interpolation filter having the impulse response shown in the Ministry of Posts and Telecommunications Ordinance No. 16 Appendix 5, No. 24.3 [M sample /
This is achieved by re-sampling in [seconds].

The impulse response coefficient described in Appendix No. 16 of the Ministry of Posts and Telecommunications Ordinance No. 16 is shown in FIG. 5, and the frequency characteristic of this impulse response is shown in FIG. Further, the operation of the sampling frequency conversion circuit 6 shown in FIG. 4 will be described with reference to FIG. Sampling frequency conversion circuit 100 of FIG.
Is composed of a zero point insertion circuit 102, an interpolation filter 103, and a resampling circuit 104.

A signal interpolated between frames is input to the input terminal 101 of the sampling frequency conversion circuit 100. The sampling frequency of the signal interpolated between the frames is 32.4 [M samples / second]. Zero point insertion circuit 1
02 is between each sampling point of the 32.4 [M samples / sec] interframe interpolation signal input from the input terminal 101,
Insert two sample points each with a value of zero, for convenience 97.2
Obtain a digital signal of [M samples / sec].

The interpolation filter 103 is a zero point insertion circuit 1.
The digital signal of 97.2 [M sample / sec] from 02 is filtered with the impulse response of FIG.
A value is interpolated with respect to the zero point inserted by the zero point insertion circuit 102. The resampling circuit 104 is an interpolation filter 1
From the digital signal of 97.2 [M sample / sec] interpolated in 03, the inter-field sub-sampling phase of the transmission control signal included in the MUSE signal (bit number 1)
, One data is taken every 4 samples,
A digital signal of 24.3 [M samples / sec] is obtained.

From the output terminal 105 of the sampling frequency conversion circuit 100, the digital data of 24.3 [M samples / sec] output from the resampling circuit 104 is output. A, B of the sampling frequency conversion circuit 100,
The digital sampling points in C and D are shown in FIG.
8 (A), FIG. 8 (B), FIG. 8 (C), and FIG. 8 (D).
FIG. 8A shows sample points of the inter-frame interpolation signal input to the input terminal 101. The inter-frame interpolated signal has a sampling frequency of 32.4 [M samples / sec]. sa0, sa1, sa2, sa3, and sa4 represent signal sample points. The frequency components of the signal of FIG. 8 (A) are shown in FIG. 9 (A).

FIG. 8B shows output sample points of the zero point insertion circuit 102. Two zero points z0 to z7 are inserted between the sample points of the input inter-frame interpolation signal, and 97.2
A digital signal of [M samples / second] is generated. The frequency components of the signal of FIG. 8B are shown in FIG. 9B. FIG. 8C shows the output sampling points of the interpolation filter 103. The interpolation filter processing is performed on the signal output from the zero point insertion circuit 102 to obtain the sampling data of sb0 to sb12. FIG. 9C shows the frequency characteristic of the filter having the impulse response characteristic of FIG. 5 used in the interpolation filter 103.

The frequency component of the digital output signal of the interpolation filter 103 is the product of the frequency component of the output signal of the zero point insertion circuit 102 and the frequency characteristic of the interpolation filter of the interpolation filter 103, as shown in FIG. It is shown as (D). FIG. 8D shows the output sampling points of the resampling circuit 104. One sample data is taken out every four samples from the signal output from the interpolation filter 103, and a digital signal of 24.3 [M samples / sec] is obtained. Is being generated. The signal in FIG. 8D becomes the output signal of the sampling frequency conversion circuit 100.

[0017]

FIG. 10 shows the procedure of band compression for a video signal on the MUSE encoder side. In the MUSE transmission method, in order to faithfully reproduce the inter-field interpolation signal from the inter-frame interpolation signal on the decoder side, the frequency conversion 303 on the MUSE encoder side and the sampling frequency conversion circuit on the MUSE decoder side shown in FIG. When 6 is connected in series, the relative amplitude is 0.5 at 12.15 [MHz].
The phase linear roll-off characteristic must be

According to the Ordinance No. 16 of the Ministry of Posts and Telecommunications, offset sub-sampling between fields 3 on the transmitting side, that is, the encoder side.
02 to interframe offset subsampling 304
The frequency characteristics up to immediately before are specified such that the phase linear roll-off characteristics with a relative amplitude of 0.5 at 12.15 [MHz] are obtained when the filters having the impulse characteristics shown in Fig. 5 are connected in cascade. Therefore, in the conventional MUSE decoder, the process of generating the inter-field interpolation signal from the inter-frame interpolation signal, that is, the sampling frequency conversion circuit 10
0, the filter having the frequency characteristic shown in FIG. 6 has been used as the interpolation filter 103 shown in FIG.

However, as a result, the aliasing frequency component of the inter-input frame interpolated signal indicated by the hatched portion in FIG. 9D remains in the output signal of the interpolating filter 103. Therefore, the resampling circuit 104 extracts a digital signal of 24.3 [Msample / sec] from a digital signal of 97.2 [Msample / sec], so that the aliasing frequency component is as shown by the shaded portion in FIG. 9 (E). , And remains as a DC component and a low frequency component signal of the output signal, which interferes with the original luminance signal and deteriorates the image quality.

The present invention has been made in consideration of the above points, and eliminates unnecessary frequency component folding back to the low frequency band that has occurred in sampling frequency conversion, and accurately interpolates still images by field interpolation processing. MUSE that can be played back to improve image quality
An attempt is made to propose a signal decoding device.

[0021]

SUMMARY OF THE INVENTION In order to solve the above problems, in the present invention, 12.15 [MHz] or more and 16.2 [M]
The sampling frequency conversion circuit 200 having the low-pass filter 204 having a cutoff frequency in the range of [Hz] or less is provided.

Further, in the present invention, the sampling frequency conversion circuit 200 includes, in addition to the low-pass filter 204,
Zero point inserting means 202 for inserting two zero points per sample point, filter 203 having an impulse response based on the Ministry of Posts and Telecommunications Ordinance No. 16 Appendix Table 5, and re-sampling for extracting one sample point at 4 sample periods. And means 205.

[0023]

[Function] A filter 203 having an impulse response of the Ministry of Posts and Telecommunications Ordinance No. 16 attached table No. 5, and 12.15 [MHz] or more 16.2
The low-pass filter 204 having a cutoff frequency in the range of [MHz] or less is provided, and the signal interpolated in the frame in the MUSE decoding process is used in the sampling frequency conversion circuit 200 in the impulse characteristic of the Ministry of Posts and Telecommunications Ordinance No. 16 Appendix Table 5 With a filter 203 having 12.15 [MHz] or more 1
Processing is performed by the low-pass filter 204 having a cutoff frequency in the range of 6.2 [MHz] or less. As a result, it is possible to remove the aliasing of unnecessary frequency components into the low frequency range, which has occurred in the sampling frequency conversion circuit 200, and to accurately reproduce a still image by inter-field interpolation processing that follows the sampling frequency conversion circuit 200. Can be performed and the image quality can be improved.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

In FIG. 1, reference numeral 200 generally indicates a sampling frequency conversion circuit in the MUSE decoder according to the present invention, which includes a zero point insertion circuit 202 and an interpolation filter 20.
3, low-pass filter 204, resampling circuit 20
It is composed of 5. Sampling frequency conversion circuit 2
A signal interpolated between frames is input to the input terminal 201 of 00. The sampling frequency of the signal interpolated between frames is 32.4 [M samples / sec].

The zero point insertion circuit 202 has an input terminal 201.
Insert 2 sample points each having a value of zero between each sample point of the interpolated signal of 32.4 [Msamples / sec] input from 2 to obtain a digital signal of 97.2 [Msamples / sec]. . The interpolation filter 203 includes a zero point insertion circuit 2
The digital signal of 97.2 [M sample / sec] from 02 is filtered with the impulse response of Table 1,
A value is interpolated with respect to the zero point inserted by the zero point insertion circuit 202.

The low-pass filter 204 has a sampling frequency of 32.4 [M samples / sec] in order to remove the aliasing component generated in the zero insertion circuit 202 contained in the digital signal generated by the interpolation filter 203. The low-pass filter processing is performed to pass only the band that can transmit the inter-frame interpolated signal having and to block the other folding region.

The resampling circuit 205 uses the output signal of 97.2 [M samples / sec] from the low-pass filter 204 according to the inter-field sub-sampling phase (bit number 1) of the transmission control signal included in the MUSE signal. One data is taken every 4 samples and 24.3
Obtain a digital signal of [M samples / sec]. The output terminal 206 of the sampling frequency conversion circuit 200 outputs 24.3 [M samples /
Second] digital data is output.

In the above configuration, the digital sampling points at A, B, C, D and E of the sampling frequency conversion circuit 200 are shown in FIGS. 2 (A), 2 (B) and 2 respectively.
It is shown in correspondence with (C), FIG. 2 (D), and FIG. 2 (E). FIG. 2A shows sample points of the interframe interpolation signal input to the input terminal 201. Interframe interpolated signal is
It has a sampling frequency of 32.4 [M samples / sec]. sa0, sa1, sa2, sa3, sa4 represent the signal sampling points. FIG. 3 shows the frequency components of the signal of FIG.
It shows in (A).

FIG. 2B shows output sample points of the zero point insertion circuit 202. Two zero points z0 to z7 are inserted between the sample points of the input inter-frame interpolation signal,
It produces a digital signal of 97.2 [M samples / sec]. The frequency components of the signal of FIG. 2 (B) are shown in FIG. 3 (B). FIG. 2C shows the output sample points of the interpolation filter 203. The interpolation filter processing is performed on the signal output from the zero point insertion circuit 202 to obtain the sampling data of sb0 to sb12. FIG. 3C shows the frequency characteristic of the filter having the impulse response characteristic of FIG. 5 used in the interpolation filter 203. The frequency components of the signal of FIG. 2C are shown in FIG.

FIG. 2D shows output sample points of the low pass filter 204. FIG. 3E shows the frequency characteristic of the low-pass filter used in the low-pass filter 204.
FIG. 3F shows output signal frequency characteristics of the low-pass filter 204. The folded signal component due to the zero point insertion, which is represented by the shaded portion in FIG. 3D, is removed by passing through the low-pass filter 204 having the characteristic shown in FIG.

FIG. 2 (E) shows the output sampling points of the resampling circuit 205, and the low pass filter 204 is shown.
One sample data is taken out every four samples from the signal output from the digital signal, and a digital signal of 24.3 [M samples / sec] is generated. FIG. 3G shows the output terminal 206.
It shows the frequency component of the signal at.

According to the above configuration, when a signal for inter-field interpolation is generated from an inter-frame interpolated signal, a pass band of approximately 16.2 [MHz] or less is used in addition to the filter according to the Ordinance No. 16 of the Ministry of Posts and Telecommunications. By inserting a low-pass filter that
It is possible to remove the aliasing of unnecessary frequency components to the low frequency range, which has occurred in the sampling frequency conversion circuit 200, and thereby realize a MUSE decoder that can accurately perform inter-field interpolation processing and improve image quality.

In the above-mentioned embodiment, the case has been described in which the interpolating filter constitutes a filter according to the Ordinance No. 16 of the Ministry of Posts and Telecommunications and the low pass filter has a pass band of about 16.2 MHz or less. The interpolating filter and the low-pass filter are each a linear processing circuit. One filter circuit having a frequency characteristic obtained by multiplying the frequency characteristics of two circuits is a filter according to the Ministry of Posts and Telecommunications Ordinance No. 16 and about 16.2 [MHz]
A filter having the following pass band may be realized.

In the above embodiment, the case where the pass band of the low-pass filter is about 16.2 [MHz] or less has been described, but the cut-off frequency of the low-pass filter is about 1.
The cutoff frequency is not limited to 6.2 [MHz] or less, but in the range of 12.15 [MHz] or more and 16.2 [MHz] or less considering the phase linear roll-off characteristics when the filters according to the Ministry of Posts and Telecommunications Ordinance No. 16 are connected in series. If set, the same effect as that of the above-described embodiment can be realized.

[0036]

As described above, according to the present invention, it is possible to remove the aliasing of unnecessary frequency components to the low frequency range, which has occurred in the sampling frequency conversion circuit, and to reduce the distance between the fields following the sampling frequency conversion circuit. It is possible to realize a MUSE signal decoding device capable of performing accurate still image reproduction by interpolation processing and improving image quality.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a sampling frequency conversion circuit in a MUSE signal decoding device according to the present invention.

FIG. 2 is a schematic diagram for explaining sampling points of a digital signal in the sampling frequency conversion circuit of FIG.

FIG. 3 is a signal waveform diagram showing frequency components of a digital signal for explaining the operation of the sampling frequency conversion circuit of FIG.

FIG. 4 is an MU provided with a sampling frequency conversion circuit.
It is a block diagram which shows the structure of an SE decoder.

FIG. 5 is a chart showing impulse responses shown in Appendix No. 16 of the Ministry of Posts and Telecommunications Ordinance No. 16;

FIG. 6 is a characteristic curve diagram showing a frequency characteristic of a filter having an impulse response of Ministry of Posts and Telecommunications Ordinance No. 16 Appendix No. 5;

FIG. 7 is a block diagram showing a conventional sampling frequency conversion circuit.

8 is a schematic diagram for explaining sampling points of a digital signal in the sampling frequency conversion circuit of FIG.

9 is a signal waveform diagram showing frequency components of a digital signal for explaining the operation of the sampling frequency conversion circuit of FIG.

FIG. 10 is a block diagram showing a procedure of band compression in the MUSE encoder.

[Explanation of sign]

1 ... A / D converter, 2 ... Transmission processing circuit, 3 ... Control code demodulation circuit, 4 ... Luminance signal processing circuit,
5 ... Interpolation circuit between frames, 6, 9, 100, 200 ...
… Sampling frequency conversion circuit, 7 …… Field interpolating circuit, 8 …… Field interpolating circuit, 10 …… MIX
Processing circuit, 11 ... Chroma signal processing circuit, 12 ... Motion detection circuit, 13, 14, 15 ... Time axis expansion circuit, 16
... Inverse matrix circuit, 17, 18, 19 ... Gamma correction circuit, 20, 21, 22 ... D / A converter, 102,
202 ... Zero point insertion circuit, 103, 203 ... Interpolation filter, 104, 205 ... Resampling circuit, 20
4 ... Low-pass filter.

[Procedure amendment]

[Submission date] January 24, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

A signal interpolated between frames is input to the input terminal 101 of the sampling frequency conversion circuit 100. The sampling frequency of the signal interpolated between the frames is 32.4 [M samples / sec]. The zero point insertion circuit 102 receives 32.4 input from the input terminal 101.
Two sample points each having a value of zero are inserted between each sample point of the inter-frame interpolated signal of [M sample / sec], and for convenience, a digital signal of 97.2 [M sample / sec] is obtained. .

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0023

[Correction method] Change

[Correction content]

[0023]

[Function] A filter 203 having an impulse response of the Ministry of Posts and Telecommunications Ordinance No. 16 attached table No. 5, and 12.15 [MHz] or more 1
The low-pass filter 204 having a cutoff frequency in the range of 6.2 [MHz] or less is provided, and the signal interpolated between frames in the MUSE decoding process is sampled in the sampling frequency conversion circuit 200 by the Ministry of Posts and Telecommunications Ordinance No. 16 Appendix Table No. 5 Filter 203 having impulse characteristics of 12.15 [MH
Processing is performed by the low-pass filter 204 having a cutoff frequency in the range of z] to 16.2 [MHz]. This allows
It is possible to remove the unnecessary aliasing of frequency components to the low frequency range that has occurred in the sampling frequency conversion circuit 100, and perform accurate still image reproduction by inter-field interpolation processing that follows the sampling frequency conversion circuit 200. Therefore, the image quality can be improved.

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

In FIG. 1, reference numeral 200 generally indicates a sampling frequency conversion circuit in the MUSE decoder according to the present invention, which includes a zero point insertion circuit 202 and an interpolation filter 20.
3, low-pass filter 204, resampling circuit 20
It is composed of 5. Sampling frequency conversion circuit 2
A signal interpolated between frames is input to the input terminal 201 of 00. The sampling frequency of the signal interpolated between frames is 32.4 [M samples / sec].

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

The zero point insertion circuit 202 has an input terminal 201.
Two sample points each having a value of zero are inserted between each sample point of the inter-frame interpolation signal of 32.4 [M sample / second] input from Get the digital signal. The interpolation filter 203 performs the filter processing with the impulse response of FIG. 5 on the digital signal of 97.2 [M samples / sec] from the zero point insertion circuit 202, and the zero point inserted by the zero point insertion circuit 202. Interpolate the value for.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Change

[Correction content]

According to the above configuration, when the inter-field interpolation signal is generated from the inter-frame interpolation signal, about 16.2 [MHz] or less is passed in addition to the filter in accordance with the Ordinance No. 16 of the Ministry of Posts and Telecommunications. By inserting the low-pass filter as the band, it is possible to remove the aliasing of the unnecessary frequency component generated in the sampling frequency conversion circuit 100 to the low band, and thereby the inter-field interpolation processing can be accurately performed. A MUSE decoder that can improve image quality can be realized.

[Procedure correction 6]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a sampling frequency conversion circuit in a MUSE signal decoding device according to the present invention.

FIG. 2 is a schematic diagram for explaining sampling points of a digital signal in the sampling frequency conversion circuit of FIG.

FIG. 3 is a schematic diagram showing frequency components of a digital signal for explaining the operation of the sampling frequency conversion circuit of FIG.

FIG. 4 is an MU provided with a sampling frequency conversion circuit.
It is a block diagram which shows the structure of an SE decoder.

FIG. 5 is a chart showing impulse responses shown in Appendix No. 16 of the Ministry of Posts and Telecommunications Ordinance No. 16;

FIG. 6 is a characteristic curve diagram showing a frequency characteristic of a filter having an impulse response of Ministry of Posts and Telecommunications Ordinance No. 16 Appendix No. 5;

FIG. 7 is a block diagram showing a conventional sampling frequency conversion circuit.

8 is a schematic diagram for explaining sampling points of a digital signal in the sampling frequency conversion circuit of FIG.

9 is a schematic diagram showing frequency components of a digital signal for explaining the operation of the sampling frequency conversion circuit of FIG.

FIG. 10 is a block diagram showing a procedure of band compression in the MUSE encoder.

[Explanation of reference signs] 1 ... A / D converter, 2 ... Transmission system processing circuit, 3 ... Control code demodulation circuit, 4 ... Luminance signal processing circuit,
5 ... Interpolation circuit between frames, 6, 9, 100, 200 ...
… Sampling frequency conversion circuit, 7 …… Field interpolating circuit, 8 …… Field interpolating circuit, 10 …… MIX
Processing circuit, 11 ... Chroma signal processing circuit, 12 ... Motion detection circuit, 13, 14, 15 ... Time axis expansion circuit, 16
... Inverse matrix circuit, 17, 18, 19 ... Gamma correction circuit, 20, 21, 22 ... D / A converter, 102,
202 ... Zero point insertion circuit, 103, 203 ... Interpolation filter, 104, 205 ... Resampling circuit, 20
4 ... Low-pass filter.

[Procedure Amendment 7]

[Document name to be corrected] Drawing

[Name of item to be corrected] Figure 6

[Correction method] Change

[Correction content]

[Figure 6]

Claims (4)

[Claims] 1. An M comprising a sampling frequency conversion circuit having a low-pass filter having a cutoff frequency in the range of 12.15 [MHz] or more and 16.2 [MHz] or less.
USE signal decoding device. 2. The sampling frequency conversion circuit comprises, in addition to the low pass filter, zero point insertion means for inserting two zero points per sample point, and impulse based on the Ministry of Posts and Telecommunications Ordinance No. 16 Appendix Table No. 5. A filter having a response,
2. The MUS according to claim 1, further comprising: re-sampling means for taking out one sample point at four sample periods.
E signal decoding device. 3. The low-pass filter and the filter are:
It is a filter that has a frequency characteristic that is obtained by multiplying the frequency characteristic by the impulse response of the Ministry of Posts and Telecommunications Ordinance No. 16 Appendix No. 5 and the frequency characteristic for low-pass with a cutoff frequency in the range from 12.15 [MHz] to 16.2 [MHz]. The MUSE signal decoding device according to claim 2, wherein 4. The sampling frequency conversion circuit performs processing of a still image system.
Alternatively, the MUSE signal decoding device according to claim 3.