JPH03295376A - High-definition TV receiver with strobe function - Google Patents

Abstract

PURPOSE:To execute adaptation to a television receiver decoding a signal which is offset subsampling band-compressed and transmitted into the original television signal of a wide band by compulsorily outputting a strobe picture as a still picture mode while the output of a small screen sample circuit is circulated in field memories. CONSTITUTION:The field memories 110 and 112 provided for the decoder part of the receiver restoring the high dignity television signal which is offset subsampling band-compressed and transmitted into the original signal are used. Respective field pictures which are made into small screens for the strobe picture from a signal which is moving picture-processed in a decoder part are written into the field memories 110 and 112. When strobe picture date written into the field memories 110 and 112 after they are written, the signal is compulsorily still picture-processed and it is guided to an output. Thus, the strobe picture of high resolution can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a television receiver that decodes a high-definition television signal transmitted through offset subsampling band compression into an original wideband television signal.

In particular, the present invention relates to a signal processing circuit suitable for providing a strobe function to this receiver.

[Conventional technology]

As an example of a method for compressing and transmitting a broadband high-definition television signal to a practical level band that can be transmitted, there is a ``Hi-Vision Broadcasting Using Satellites'' by Yu Ninomiya in Nikkei Electronics, No. 433, January 2, 1987. There is a MUSE method, which is discussed in the document entitled "Transmission Method MUSE". Further, as a prior art special function, there is, for example, a freeze function of a MUSE decoder described in Japanese Utility Model Application Publication No. 60-2929 "High Definition TV Receiver".

[Problem to be solved by the invention]

As shown in the conventional example, for example, a MUSE system receiver, which is a type of high-definition television receiver, has a freeze function as a special function, but does not have any other special functions. An object of the present invention is to provide a signal processing circuit that enables a strobe function suitable for a television receiver that decodes a signal compressed and transmitted in an offset subsampling band like the MUSE method into an original wideband television signal. be.

[Means to solve the problem]

The above purpose is to store the video signal for at least two fields. a second field memory, an incoming signal and a first field memory;
Or a still image processing circuit that performs still image processing on a signal interpolated between frames with the video signal of the previous frame from the second field memory output.

a video processing circuit for processing video; a mixer for adaptively mixing the output signals of the still image processing circuit and the video processing circuit; Second
small screen sample circuit, and the first small screen sample circuit. a first switch circuit that performs the interframe interpolation process by switching between a signal delayed by one frame by a second field memory and an incoming signal; an output of the first switch circuit and the first small screen sample circuit; a second switch circuit that switches between the output of the first field memory and the output of the second small screen sample circuit and leads the output to the first field memory; a third switch circuit leading to the memory; and a third switch circuit that provides write and read timing and addresses to the first to ninth second field memories in the strobe mode; Second
．． The switching operation of the third switch circuit and the stopping of the motion vector and the stopping of low frequency switching in the strobe mode.

A strobe control circuit for forcibly controlling the mixing ratio in the mixer is provided, and the output of this control circuit causes the first strobe mode to be controlled from the start of the strobe mode. The output of the second small screen sample circuit is the output of the first small screen sample circuit. While writing to the second field memory, the mixer is forced into the moving image mode, and when the writing is completed and the strobe image is output, the first.
While circulating in the second field memory, the strobe image is forcibly output in the mixer as a still image mode.

[Effect]

During strobe mode, the first switch circuit first guides the incoming signal to the video processing circuit, and the second switch circuit first guides the incoming signal to the video processing circuit. The third switch circuit is the first switch circuit. The output of the second small screen sample circuit is the output of the first small screen sample circuit.
Lead to the second field memory. The output of the video processing circuit is the first one. The second small-screen sample circuit thins out each sample to prevent it from looking unnatural during interlacing, and uses the strobe image data as strobe image data. Write to second field memory. At this time, the strobe control circuit is controlled by the first strobe control circuit. Gives an address for dividing and writing strobe image data into n small screens into the second field memory. Also, in this way, the strobe image data is transferred to the first. While writing to the second field memory, the mixer outputs a video processed signal of the incoming signal from the video processing circuit in a forced video mode by a strobe control signal. Said first and second
When writing of the strobe image data to the field memory of the first field memory is completed, the first field memory is written. Second. The third switch circuit selects the opposite side to the first one. The strobe image data in the second field memory is circulated within the memory, and the strobe image data circulating within this memory is transmitted to the first field memory.
The signal is guided to the still image processing circuit through the switch circuit, and output as a forced still image mode in the mixer. Further, in the strobe mode, motion correction in the first and second field memories using a motion vector signal for motion correction is stopped. Similarly, even if it has a function of substituting low frequency components with the incoming signal, this substituting function is stopped.

The above signal processing enables the strobe function.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

Figure 1 shows an example in which a strobe function is realized in a circuit that decodes the band-compressed video signal into the original wide-band signal in a MUSE receiver that transmits high-definition television signals with offset subsampling band compression. shows. 101 is an input terminal for an analog high-definition television signal (hereinafter referred to as MUSE signal) band-compressed by the MUSE method, 102 is an A/D converter that converts the analog MUSE signal into a digital signal, and 103 is a MUSE signal.
A synchronization processing circuit detects each control signal and synchronization signal multiplexed in the signal and outputs each detected signal to each signal processing section. 104 and 105 are a horizontal synchronization signal (HD) from the synchronization processing circuit 103 and a vertical synchronization signal. 106 is a de-emphasis circuit; 107 is a noise reducer circuit (hereinafter referred to as NR); t 108,1 a synchronization signal (VD) output terminal;
09°111.113 is the first switch which performs different switching operations in normal mode and strobe mode. Second. The third and fourth switch circuits 1.10 and 112 are the first switch circuits 1.10 and 112 for interframe interpolation. Second field memory.

] 14 is a motion detection circuit that detects the amount of motion between one frame or two frames, and 115 is an interpolated M between frames.
A low-pass filter for still images that limits the band of the USE signal for still image processing (hereinafter referred to as LPF for still images).
, 118 is a moving image LPF that performs field interpolation based only on the currently arriving MUSE signal.

116.11.9, 1.24 are frequency converters that convert the sampling frequency; 117 is an interfield interpolation filter that interpolates the still image processing signal with the signal one field before;
12o is a mixer (hereinafter referred to as MIX) that adaptively mixes the still image processing signal from the interfield interpolation filter 117 and the video processing signal from the frequency converter 119 according to the amount of motion from the motion detection circuit 114; , 122 is a moving picture LPF that performs filter processing to create strobe image data from a signal interpolated within the field using only the currently arriving MUSE signal. The second single-screen sampling circuit 123 is an L P F that passes the low-frequency components of the currently arriving MUSE signal that do not include aliasing components.

125 is a low frequency component in the currently arriving MUSE signal and M I
], 20 is a low frequency switching circuit for replacing the low frequency components in the adaptively processed signal; ] 26 is an input terminal for the control signal of the strobe motor; 127 is the first, second, . Third
．． Fourth switch circuit 108°109.111. ．． 11
3 and the above 1. Second field memory 110, 112
and the M I X, 120 and the low frequency switching circuit code.
128 is a chroma decoding circuit that returns the chroma signal whose time axis has been compressed to 1/4 to its original time axis.

129 is a chroma line II decoding circuit that decodes line-sequential chroma signals into simultaneous signals; 130 is an inverse matrix that converts Y, R-Y, B-Y signals decoded into original broadband signals into RGB signals;

131, 132, and 133 are the first . Second. The third D/A converter, 134, 135, 136 is an analog signal RG
This is the output terminal for the B signal.

Next, the operation will be briefly explained.

In normal mode, the first switch circuit 108 is NR107
Interframe interpolation is performed by interpolating the current signal from the field memory 112 and the previous frame signal from the second field memory 112 dot by dot or by switching using the sample clock. Also, the second and third switch times $10
9 and 111 are connected in reverse to the illustration, and the first switch circuit], 08 is connected to the first field memory 110.
A signal from the first field memory 112 is stored in the second field memory 112.
A fourth switch circuit 113 to which the output of the field memory 110 is guided is also connected in the opposite direction to that shown in the figure, and guides the motion vector for motion correction to the second field memory 112 to perform motion correction between frames. Let's do it. On the other hand, in the strobe mode, the first switch circuit 1.08 stops the switching operation based on the sample clock signal, and is initially connected in the opposite direction as shown in the figure, so that only the current signal from the NR circuit 107 is transmitted to the second switch circuit. 109. Still image LPF1
15, the signal is guided to the moving image LPF 118 and the chroma processing 128. At this time, the second. third switch circuit 109,
111 is connected in the same way as shown in the drawing, contrary to the normal case.

As a result, small screen sample circuits 121 and 122, which will be described later,
The output data is stored in the first and second field memories 110,
Guided to 112. FIG. 2 is an example of a strobe image display when nine strobe images are displayed. For example, when realizing these nine strobe images with the present invention, the first .
The strobe image data from the second small screen sample circuit is A
, B, C, D, E, F, G, H, I in the order of 1 field at a time. The data is written to the second field memory 110,112. This write address is controlled by the strobe control circuit 127. On the other hand, while writing the strobe image data for 9 fields into the first and second field memories 110 and 112, the MIX 120 is forced into the video mode by the control signal of the strobe control circuit, and the video LPF 1
18 and a frequency converter 119 to output a signal obtained by subjecting the current signal to video processing. Next, this first. After writing the strobe image data for nine screens into the second field memories 110, 112, the second switch circuit 108 is connected to the second field memory 110, 112 in the same manner as shown in the figure. The third switch circuit 109[deg.] 11 is connected in the opposite direction to that shown in the figure, and the strobe image data written in the first and second field memories 110 and 112 is circulated within the memories. This allows the first
The strobe image data circulating in the second field memories 110 and 112 is always sent to the first switch circuit 108.
Through the LPF for still images 15. Video LPF 118
．． It is directed to chroma processing circuit 128. In this case, MIX
120 is set to forced still image mode, and strobe image data is output to the still image LPF 115. Frequency conversion 116. The still image processed signal is forcibly guided by the interfield interpolation filter 117. Further, at this time, the output of the frequency converter 124 is a low frequency signal of the current signal extracted by the LPF 123 and is different from the strobe image data, so the low frequency replacement with the current signal is stopped. In addition, the synchronization processing circuit 10
The motion vector in the M[1SE signal detected in step 3 is, for example, a vector quantity that performs motion compensation between the current signal and the signal in the previous frame.In strobe mode, the motion vector guided to the second field memory 112 is cut off and do not perform motion compensation. As a result, the amount of delay of the second field memory 112 does not depend on the motion vector, and the total amount of delay due to the circulation of the two field memories can always be one frame. For this purpose, for example, the fourth switch circuit 113 is connected in the same manner as shown.

Through the above operations, the strobe image data is transferred to the first. Even during writing to the second field memories 110, 112, the current signal that has undergone moving image processing is always output, and even when outputting a strobe image, a high-quality strobe image that has been subjected to still image processing can be obtained.

Next, a specific example of a circuit suitable for the small screen sample circuits 121 and 122 that affect the image quality of a strobe image will be described.

Figure 3 shows an example of this small screen sample circuit.

This is an example of applying filter processing to the MUSE signal interpolated within the field to make it suitable for small screens.
is an output terminal for strobe image data, 304° 314 is an IH delay line that delays the input signal by one line, 305, 306
, 310, 311, 317° 318.319 is a coefficient multiplier,
307, 312, 320 are adders, 308, 309, 3
13,315°316.321 is latch, 322,33
0, 331 are clock input terminals, 323, 327 are 1/
3 frequency divider, 324, 329 are gate circuits, 325°32
8 is an inverter, and 326 is a pulse input terminal with one line period.

This example shows the case of creating a 1/9 small screen, and the output of the first small screen sample circuit 121 that creates 1 pixel from 4 pixels in the horizontal and vertical directions is sent to the high-power terminal 302 from 3 pixels in the horizontal direction. The output of the second small screen sample circuit 122 that produces one pixel is led to the output terminal 303. At this time, in order to prevent deterioration of horizontal resolution due to filter processing,
Pixel alignment is performed so that the pixel center of gravity filtered in the second small screen sample circuit 121 and the pixel center of gravity filtered in the second small screen sample circuit 122 have a 1/2 interlace relationship. This situation is shown in Figure 4. As a result, signals are written in the first and second field memories 110 and 112 in units of 3 lines in the vertical direction and in units of 173 dots in each horizontal direction.

Note that the same operation can be performed when n strobe screens are displayed.

FIG. 5 shows another embodiment of the present invention.

In FIG. 5, reference numerals 301 and 302 indicate fifth switches that perform different switching operations between normal times and strobe mode. 6th
The switch circuits 303 are the first and second switch circuits. Third. 4th. Fifth. Sixth switch circuit 108, 109, 111, 11
3,301,302, and MIX]
, 20 still image and video mixing ratios, and a low frequency change of 12
This is a small screen control circuit that controls the stop of 9. The rest is the same as the embodiment shown in FIG.

In the first embodiment, all the strobe data for 9 images are stored in the first image. The method used was to write data to the second field memory 110, 112 and then read it out sequentially and cycle through it. However, in this embodiment, each time the strobe image data for one image is written to the field memory 1, 10, 112, the small screen It is characterized by the fact that the current signal is processed as a moving image, except for the small screen display section.

The operation will be explained below.

In FIG. 5, in the normal mode, the second. 3. The fourth switch circuits 109, 111, and 113 are connected in the opposite way to that shown, and operate in the same manner as in the normal mode mode of the embodiment shown in FIG. Fifth. The sixth switch circuits 301 and 302 are also connected in the opposite direction to that shown in the figure, and the fifth switch circuit 301 switches the output of the first switch circuit 08 using the resampling clock as the still image LPF 115. The sixth switch circuit 302 leads the output of the fifth switch circuit 301 to the moving image L P F i i 8 and the chroma processing 128.

Next, when using strobe mode, the second Third switch circuit 1
09 and 111 are connected in the same way as shown in the figure, and the small screen sample circuit 1 is connected as in the strobe mode of the embodiment shown in FIG.
．． The outputs of 21 and 122 are input to the first and second field memories 110 and 112. At this time, the first switch circuit transfers the strobe image data of the second field memory 112 to the fifth switch circuit 301, and the fifth switch circuit 301 transfers the output of the first switch circuit 108 to the still image LPF15. The first switch circuit 108 is connected to the sixth switch circuit 302 in the same way as shown, and the fifth switch circuit 3C) is connected in the opposite way to that shown. Further, the seventh switch circuit 302 is connected in the same manner as shown in the figure, and only the current signal from the NR circuit 1.07 is used as the moving image L P
F 118 and chroma processing 128. 1st. Second
While the first strobe image data is being written into the field memories 110 and 112, the MIX 120 is forced into a moving image mode, and a signal obtained by processing the current signal from the sixth switch circuit 302 into a moving image is output.

A method for sequentially displaying small screens when strobe image data is sequentially written into the two field memories 110 and 112 will be described below.

FIG. 6 is an explanatory diagram of this small screen display. For example, the 6th
Figure (a) is an example of writing and displaying the first strobe image data. In this case, the first small screen processed as a still image is displayed in the area (A) of the display screen, and the video processed as a moving image of the current signal is displayed in the area (B). In this case, the period corresponding to the scanning period from (a) to (b) and the scanning period from (1) to (1) of area (A) of the display screen, for example, is stored in the second field memory] 12. The strobe image data of the first strobe image is sequentially read out and output as a forced still image mode at MIX 120. Otherwise, the current signal guided by the sixth switch circuit 302 is outputted to MIX 120.
0 to output as forced video mode.

FIG. 6(b) is an example of writing and displaying a second strobe image. After writing the strobe data for the two flashes in area (C) shown in FIG. are connected in the same way. At this time, for example, in FIG. 6(b), the first and second small screens processed as still images are displayed in areas (A) and (C) of the display screen, and the current signal is displayed in area (B). Displays video processed video. For this reason, for example, from (o) to (force), (a) to (a), (a) to (k), and (tsu) to (1) in the (A) and (C) areas of the display screen.

During the scanning period from (1) to (ri), the first and second strobe image data stored in the first field memory 110 are sequentially read out and output as forced still image mode by the MIX 120. 6th switch circuit 3 except for
The current signal led by 02 is output as a forced moving image mode at M I X, 1.20. The method of displaying the third and subsequent small screens is similar. When all displayed images become strobe images, the fifth switch circuit 301 repeats the switching operation for each field, and the still image LPF1
15, the strobe image data in the first field memory 110 is connected in the same way as shown in the figure, and when the strobe image data in the second field memory 112 is led to the strobe image data, the connection is reversed from that shown. Also, at this time, the MIX 120 outputs the forced still image mode. Other operations are similar to those in the strobe mode shown in FIG.

〔Effect of the invention〕

According to the present invention, a field memory provided in a decoder section of a receiver that restores a high-definition television signal compressed and transmitted with an offset subsampling band to the original signal is used, and a signal processed by the moving image in the decoder section is stored in the field memory. Each field image is written as a small screen for strobe images, and when the strobe image data written to the field memory is read out after writing, the signal is forcibly processed as a still image and guided to output, resulting in high-resolution images. You can get strobe images.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a diagram showing an example of strobe image display when nine strobe images are displayed. FIG. 3 is a diagram showing an embodiment of a small screen sample circuit. FIG. 4 is a diagram showing how the small screen sample circuit thins out input signals. FIG. 5 is a diagram showing another embodiment of the present invention. FIG. 6 is an explanatory diagram of small screen display. 101-10l- Signal input terminal. 102- A/D converter, 103 - synchronous processing circuit. 106・De-emphasis circuit. 107-Rise reducer circuit. 108.109,111,113,301,302...
switch circuit. 110 First field memory. 112 Second field memory. 115...LPF for still images. 116.1], 9,124...frequency converter. 117. Interpolation filter between fields. 118・LPF for video, 120 MIX circuit. 120.121・Small screen sample circuit. 123...LPF. 125...Low frequency replacement circuit. Yu (θ) Power 4 Akiotsume

Claims (1)

[Claims] 1. In a high-definition television receiver that decodes a high-definition television signal transmitted with band compression into the original wideband television signal, a delay that delays the band-compressed high-definition television signal by at least four fields. a video processing circuit that processes a band-compressed high-definition television signal as a video signal; a still-image processing circuit that performs still-image processing on the band-compressed high-definition television signal; and a video processing circuit that processes a video signal processed by the video processing circuit. A small screen sample circuit thinned out for small screens, a mixer that adaptively mixes a signal from the video processing circuit and a signal from the still image processing circuit, and a switch circuit provided before and after the delay circuit. writing a moving image processing signal subjected to intra-field interpolation processing by the moving image processing circuit to the field memory via the small screen sampling circuit, and when writing to the field memory is completed and outputting a strobe image,
A high-definition television receiver with a strobe function, characterized in that strobe image data read from the field memory is forcibly subjected to still image processing and outputted from the mixer. 2. In the high-definition television receiver with strobe function described in claim 1, while strobe image data is being written into the field memory, the currently arriving signal is processed within the field by the video processing circuit. A high-definition television receiver with a strobe function, which performs interpolation processing and forcibly outputs the video processed signal from the mixer. 3. In the high-definition television receiver with a strobe function as set forth in claim 1, the television receiver includes means for detecting a motion vector signal for motion correction sent from the transmitting side, and the means. A strobe function characterized in that it has a motion correction means using the field memory based on a motion vector signal detected by the field memory, and stops the motion correction using the motion vector during writing or reading of strobe image data to the field memory. High definition TV receiver. 4. The high-definition television receiver with a strobe function as set forth in claim 1, comprising a low-frequency switching circuit that switches between the low-frequency components of the currently arriving signal and the low-frequency components of the output of the mixer. What is claimed is: 1. A high-definition television receiver with a strobe function, which also stops low-frequency switching by the low-frequency switching circuit when outputting strobe images.