JPH04273682A - Receiving and processing device for television signal - Google Patents

Abstract

PURPOSE:To eliminate loopback disturbance completely by selecting offset sampling processing for a field or a frame implemented at an encoder at the input of a high definition signal in the processing device in which a high definition and a standard TV signal are received and the system is converted into the NTSC system or the EDTV system. CONSTITUTION:A MUSE signal inputted from an input terminal 101 is inputted to a MUSE/NTSC down-converter 103. The converter 103 implements the interlace scanning of 1125 scanning lines and frequency of 30Hz, that is, generates and outputs an NTSC signal of 525/30, and band limit less than nearly 6MHz is possible in the horizontal frequency axis direction in the moving picture processing implemented therein, but the band limit in the time frequency axis direction is impossible, a loopback component appears at the reception of a still picture and picture quality is deteriorated. Then an EDTV processor 105 is used at first to eliminate loopback by frame-offset sampling.

Description

[Detailed description of the invention]

0001

TECHNICAL FIELD The present invention relates to a television signal receiving apparatus, and more particularly to a television signal receiving apparatus, whether the input television signal is a high definition television signal or a current standard television signal. The present invention relates to a reception processing device that performs signal processing on an input television signal and converts it into an EDTV or NTSC television signal.

0002

2. Description of the Related Art In recent years, as televisions have become larger, there has been a demand for higher quality display images. In response to these demands, various high-definition television systems are being studied. In Japan, MUSE (Multiple) is a high-definition television signal transmission system developed by NHK.
e Sub-Nyquist Sampling
A typical example is the encoding method, which will be explained below as an example.

[0003] The MUSE method is described in the document ``NHK Technical Research Journal, Vol. 39, No. 2, 1982, No. 172, pp. 18 to 53'', and its characteristics include a number of scanning lines of 1125 and a frame frequency of 30 Hz.
The interlace signal and screen aspect ratio are 16:9, making it wider than the current system. In addition, this MUSE method uses a multiple subsample band compression method that thins out pixels every other pixel every horizontal period for moving images, and thins out pixels every other pixel in a cycle of two frames for still images. There is also a method that compresses a signal with a still image transmission band of 24 MHz and a moving image transmission band of 16 MHz to 8 MHz and transmits the signal. Therefore, the MUSE decoder has two signal processing systems, one for still image/video processing, and one for still image/video processing.
The scale of the signal processing circuit has become extremely large, including a motion detection circuit for determining moving images, a MIX circuit for mixing still image and moving image processed signals, a frequency conversion circuit, etc. Therefore, with a simple circuit configuration, it is possible to create a device that can reproduce images transmitted using a high-definition television system on a current television receiver or a television system (EDTV) receiver that performs display using double-speed scanning. Development is also progressing. Regarding the method of converting such high-definition television signals to standard television signals or double-speed television signals (EDTV signals), please refer to "MUSE/NTSC Converter Compatible with EDTV" by Ito et al.
Television Society Technical Report, VOL. 14, NO. 8
pp 13-18 (1990).

[0004] EDTV compatible M described in this report
The major features of the USE/NTSC converter are as follows. One is the output compatible with EDTV, that is, the number of scanning lines is 1.
125 lines/frame high-definition television signal, 52
It is possible to obtain an output converted to a double-speed scanning signal of 5 lines/field. Second, we are trying to use frame memory to eliminate aliasing interference.

This converter will be explained below using FIG. 2. In FIG. 2, 201 is a MUSE signal input terminal, 202 is an amplifier circuit, 203 is an A/D conversion circuit that converts an analog signal to a digital signal, 204 is an ALC (automatic level control circuit) circuit that controls the signal level, and 205 is a A de-emphasis circuit that converts the MUSE signal that has been non-linearly processed on the encoder side into a linear state; 206 is a frame memory; 20
7 is a horizontal low-pass filter (hereinafter referred to as LPF), 2
08 is an aliasing removal circuit, 209 is a vertical LPF, 210
211 is a contour enhancement circuit, 211 is a time axis conversion circuit that reads out a signal written with a 32.4 MHz clock using a 20.16 MHz clock or a 30.24 MHz clock, 212, 213, and 214 are time axis conversion circuits; 215
, 216 is D for converting a digital signal into an analog signal.
/A conversion circuit, 217, 218, 219 are output terminals of luminance signal and color difference signal compatible with EDTV, 220, 22
Reference numerals 1 and 222 are output terminals for luminance signals and color difference signals compatible with interlaced scanning displays.

Next, the operation of FIG. 2 will be explained. The analog MUSE signal input from the input terminal 201 is the ALC
According to the control signal from the circuit, the signal is converted into a digital signal by the A/D converter 203 while accurately maintaining the signal level. The de-emphasis processing unit 205 performs processing to return the MUSE signal that has been non-linearly processed on the encoder side to a linear state, and supplies the signal to the horizontal LPF unit 207 and frame memory unit 206 at the next stage. Horizontal LPF section 2
07, the horizontal L is calculated for both the arriving signal and the signal delayed by one frame by the frame memory unit
Perform PF treatment. The aliasing removal circuit 208 has a built-in frame memory, and performs motion detection based on a two-frame difference and mixing processing. The mixing processing section obtains a signal of the current frame in the case of a moving image, and an average value signal of the current frame and the previous frame in the case of a still image, and mixes and outputs them according to the motion detection signal. The aliasing removal circuit 208 attempts to obtain a signal from which aliasing interference due to frame offset subsampling processing during still image reception has been removed. In the vertical LPF section 209, the MU
From the 1125 scanning lines of the SE signal, processing is performed to create 525 scanning lines corresponding to EDTV, with the center of gravity of the scanning lines aligned. The edge enhancement processing unit 210 performs edge enhancement processing only on the luminance signal. In the time axis conversion processing section 211, a signal is written using a write clock synchronized with the MUSE signal, and the signal is read out using a read clock corresponding to the EDTV synchronization signal. EDT above
The V signal is input to the D/A converter 215 and converted into an analog signal. The EDTV signal is also input to time axis conversion units 212, 213, and 214, where the readout frequency for time axis expansion is set to 1/2 of that of the time axis conversion processing unit 211, and interlaced readout is performed. This creates a standard television signal. The signal compatible with the above-mentioned standard television is sent to the D/A converter 216
input and converted to an analog signal.

[0007]

[Problem to be solved by the invention] M in the above conventional example
The USE decoder processes luminance and color difference signals by switching between moving image processing and still image processing depending on whether there is movement in the image. For this reason, the scale of the processing circuit has become extremely large and expensive. Incidentally, still image signal processing requires a large-scale memory with a capacity of about 8 Mbits per frame, and the MUSE decoder requires a large-scale memory of 20 Mbits or more per receiver. Furthermore, a special and very expensive display with an aspect ratio of 16:9 had to be used to display high-definition television signals. Therefore, there was a problem that the television receiving system became very expensive.

[0008] Furthermore, the conventional MUSE decoder described above has a problem in that it cannot be viewed with an NTSC system receiver that is currently widely used in general households.

[0009] Furthermore, EDTV compatible MUSE/NTSC, which takes into account the reproduction of high-definition television signals on conventional receivers,
In the converter, the aliasing removal circuit 208 obtains a signal from which aliasing interference caused by frame offset subsampling processing when receiving a still image is removed, but aliasing interference caused by field offset subsampling processing on the encoder side is not taken into account at all. It wasn't. Therefore, a signal spectrum due to field offset subsampling processing remains in the horizontal band around 6 MHz, which causes waveform distortion in the video signal.
Furthermore, there is a problem in that mosaic-like disturbances occur at vertical edges on the playback screen.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems and provide a high-definition television signal processing device that can convert a high-definition television signal into an EDTV system or an NTSC system.

[0011]

[Means for Solving the Problems] In an apparatus for receiving high-definition television signals and standard television signals, a method for performing in-field signal processing on the received high-definition television signal and converting it into a signal conforming to the NTSC system is provided. and an NT for outputting the received standard television signal and the first down-converting means from the first down-converting means.
a first input signal selection means for inputting and selectively outputting a video signal adopting the SC method; and a motion adaptive enhancement method using frame correlation for the video signal adopting the NTSC method outputted from the first input signal selection means. Perform image quality processing and EDT
EDTV processor means for converting the video signal into a V format video signal and simultaneously outputting a motion detection signal; first line memory means for inputting and delaying the EDTV video signal outputted from the EDTV processor means; The video signal output from the line memory means of No. 1 and the above-mentioned EDTV
a first adding means for inputting and averaging the video signal adopting the EDTV system outputted from the processor means;
a first mixing means for inputting the video signal output from the adding means and the video signal employing the EDTV system output from the EDTV processor means, and mixing and outputting the video signal according to the motion detection signal output from the EDTV processor means; This problem can be solved by providing a second input signal selection means for inputting and selectively outputting the video signal output from the first mixing means and the video signal employing the EDTV system output from the EDTV processor means.

0012

[Operation] When the first input signal selection means selects and outputs a standard television signal, the selected and output standard television signal is subjected to motion adaptive image quality enhancement processing using frame correlation, that is, ED processing. A high quality reproduced image can be obtained by creating a high quality video signal and selecting and outputting the output signal of the EDTV processor means using the second input signal selection means.

[0013] When the first input signal selection means selects and outputs the high-definition television signal that has been subjected to moving image processing by the first down-converter means, the field indicates that the selected and output high-definition television signal is a moving image signal. Since interpolation processing, that is, decoding according to the encoding method, is performed, the reproduced image is basically free from interfering components that cause image quality deterioration, and a faithful reproduced image can be obtained. Furthermore, if the selected output high-definition television signal is a still image signal, the above-mentioned EDT performs motion adaptive image quality enhancement processing (frame comb filter processing) using frame correlation.
By using the V processor means and the first addition means for outputting the field comb filter processed video signal, the aliasing component due to frame offset subsampling and the aliasing component due to field offset subsampling of a high definition television signal encoder are obtained. Obtain high-quality playback images with completely suppressed images. The video signal and still image signal that have been subjected to the signal processing are mixed and outputted by the first mixing means according to the movement of the video signal to become an EDTV video signal. The second input signal selection means selectively outputs the video signal output of the first mixing means. In this way, it is possible to obtain a high-quality reproduced image in which aliasing components are completely suppressed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be explained in detail below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention. In FIG. 1, 101 is an input terminal for the MUSE signal;
2 is NTSC signal input terminal, 103 is MUSE/NTS
C down converter, 104 is an input signal selection circuit, 10
5 is an EDTV processor, and 106 is an interlaced scan with a frame frequency of 30 Hz and 525 scanning lines (hereinafter referred to as 525/3), which has been improved in image quality by the EDTV processor.
107 is a line memory with a capacity for two lines, 108 is a line memory with a capacity for one line, 109 and 110 are adders, 111
112 is an input signal selection circuit, and 113 is a 525/60 video signal output terminal.

Next, the operation of FIG. 1 will be explained using FIGS. 3, 4, 5, 6, 7, 8, and 9. The system of the present invention converts the MUSE signal which is 1125/30 into 525
Existing MUSE/ which converts to NTSC signal which is /30
NTSC down converter and NT which is 525/30
This system receives MUSE signals and current standard television signals using an existing EDTV processor that performs motion-adaptive high-quality processing on SC signals using frame correlation. The MUSE/NTSC down converter referred to here takes into consideration the horizontal and vertical bandwidth of the NTSC receiver, and the signal processing when receiving the MUSE signal consists of only so-called video processing centered on intra-field interpolation processing. ing. The problem here is image quality deterioration caused by aliasing components included during still image transmission of the MUSE signal. Therefore, first, the signal component distribution state of the MUSE signal during still image transmission will be explained using FIG. FIG. 3 shows the input (M) of the input terminal 101 when receiving a still image signal.
USE) shows the aliasing component distribution included in the signal. In FIG. 3, the horizontal axis represents the horizontal frequency, the vertical axis represents the temporal frequency, G represents the original signal component in the 20 MHz band, a,
b, c, d, e, and f mean folded signal components when the original signal component is compressed to a band of 8 MHz by the MUSE method. As shown in FIG. 3, the MUSE signal during still image transmission has no aliasing components at a horizontal frequency of 4 MHz or less and a temporal frequency of 15 Hz or less. However, the horizontal frequency is 4MHz ~
Between 8MHz and around 15Hz and 45Hz in the time axis direction, there are aliasing components due to frame offset subsampling as shown in a, b, c, and d, and there are also aliasing components at the horizontal frequency of 4M.
e and f around 30Hz in the time axis direction within Hz to 8MHz
There is an aliasing component due to field offset subsampling as shown in the figure. Based on these considerations, the operation of FIG. 1 will be explained.

The MUSE signal input from the input terminal 101 is input to the MUSE/NTSC down converter 103. The MUSE/NTSC down converter 103 performs only video processing, and performs interlaced scanning (hereinafter referred to as 1125/
A 525/30 NTSC signal is created and output from a video signal for the HDTV (denoted as 30), that is, an HDTV video signal. Here, FIGS. 4(1) and 4(2) show signal passbands of moving image processing performed within the MUSE/NTSC down converter 103. (1) is a frequency characteristic focused only on the horizontal frequency axis (horizontal passband), and (2) is a characteristic viewed two-dimensionally on the horizontal frequency axis and the time-frequency axis. As shown in the figure, in the video processing performed within the MUSE/NTSC down converter 103, approximately 1
Although it is possible to limit the band to 6 MHz or less, no band limit can be performed in the time-frequency axis direction. Therefore, in the video processing performed within the MUSE/NTSC down converter 103, the time frequency 15H in FIG.
z, a, b, c, d around 45Hz, and time frequency 30
It is a filter with a passband that allows all folded components of the MUSE signal, such as those shown at e and f near Hz, to pass through. That is, MUSE/NTSC down converter 10
In the moving image processing performed in 3, when a still image signal is received, aliasing components as shown in FIGS. 3a, b, c, d, e, and f appear as interference on the screen. Furthermore, this aliasing component exists in a horizontal frequency range of 4 MHz to 8 MHz, and this signal component causes image quality deterioration. The MUSE/NTSC down converter 103 converts the still image signal containing the aliasing component into a 525/30 NTSC signal and outputs the signal. At this time, it is important to note that when creating a 525/30 NTSC signal from a 1125/30 video signal, that is, an HDTV video signal, although the scanning speed of the scanning line is converted, the field frequency remains unchanged. Therefore, the position of the folded component shown in FIG. 3 in the time-frequency direction does not change. Therefore, it is necessary to remove this aliasing interference when receiving a still image signal. In the system of the present invention, the E
A DTV processor is used to remove aliasing components (FIGS. 3a, b, c, d) due to frame offset subsampling.

The input signal selection circuit 104 selects the MUSE/
A 525/30 NTSC signal including folded components output by the NTSC down converter 103 and the input terminal 10
The standard NTSC signal input from 2 is input, selected, and output to the EDTV processor 105. First, the operation of the EDTV processor 105 when the input signal selection circuit 104 selects and outputs a standard NTSC signal input from the input terminal 102 will be described.

The EDTV processor 105 performs motion-adaptive high-quality signal processing on the standard NTSC signal output from the input signal selection circuit 104, that is, motion-adaptive luminance signal/chrominance signal separation processing (hereinafter referred to as Y/color signal separation processing). C separation) and motion adaptive scanning line interpolation processing are performed. This is shown in Figure 5.
Explain using. Figure 5 shows the structure of a 525/30 NTSC signal, where the vertical axis represents the vertical direction, the horizontal axis represents the time direction, and a, b, c, and d in the figure represent the video signal (
(scanning line), and the direction of the arrow on the time axis means the direction of the past in terms of time. In the EDTV processor 103, in order to detect the movement of the video signal, the incoming video signal a and the video signal d delayed by one frame with respect to this (the incoming video signal a and the video signal d are located at the same position on the horizontal-vertical plane). The motion of the image is detected using In addition, the standard NTSC signal is a composite video signal that includes both a luminance signal and a color signal, and the color signal component included in this video signal has a phase difference for each line and for each frame. is an inverted signal. Utilizing this property, the EDTV processor 103 uses frame sum ((a+d)/2 processing, which is generally called frame comb filter processing) for still images, and line sum ((()) for moving images, depending on the movement of the image. a+b)/2 (generally called line comb filter processing) is performed to separate the luminance signal and color signal. The video signal processed up to this point, that is, the high-quality 525/30 video signal that has been subjected to motion adaptive Y/C separation processing, is output to the output terminal 106. Furthermore, in the EDTV processor 105, according to the movement of the image, when the image is still image, the video signal a is
c is inserted between and b (generally called interfield interpolation processing), and when moving images, the average value of a and b is inserted as information between video signals a and b ((a+b)/2 This is a process that performs scanning line interpolation (generally called average interpolation) to double the number of scanning lines relative to the input signal, and converts this double-density scanning line to double speed, that is, 525/60. is being carried out. The video signal (standard NTSC signal) subjected to the above-described high-quality signal processing is input to an input signal selection circuit 112 (described later), selected, and output to an output terminal 113. Next, the operation of the EDTV processor 103 when the input signal selection circuit 104 selects and outputs the 525/30 NTSC signal including the aliasing component output from the MUSE/NTSC down converter 103 will be described using FIG.

FIG. 6 shows frequency characteristics representing the passband of the Y/C separation process, that is, the frame comb filter, among the processes performed by the EDTV processor 105. Figure 6
The area indicated by NULL (diagonal lines) is a non-passing area, and the other areas are passing areas. Comparing the frequency characteristics shown in FIG. 6 with the aliasing component distribution shown in FIG. Area NULL that can be removed by processing
It can be seen that it exists within the range (hatched). That is, by performing this frame comb filter processing, it is possible to remove aliasing components due to frame offset subsampling included in a video signal at the time of a still image. Since the video signal does not include aliasing components during moving pictures, the line comb filter processing performed when inputting the standard NTSC signal is not performed, and the input signal is used as it is as the video signal for moving pictures. A high-quality 525/30 video signal from which aliasing components due to frame offset subsampling included in the video signal processed up to this point, that is, the still image video signal is removed, is output to the output terminal 106. Furthermore, since the EDTV processor 105 performs scanning line interpolation according to the movement of the image, the resolution of still images does not deteriorate. But at this point it outputs 5
The 25/60 video signal includes aliasing components due to field offset subsampling shown in FIG. Next, the principle of removing this aliasing component is shown in Figure 7.
, will be explained using FIG.

FIG. 7(1) is a general block diagram of a field comb filter, and FIG. 7(2) is a frequency characteristic showing the pass band of the field comb filter. The area indicated by NULL in FIG. 7(2) is a non-passing area, and the other areas are passing areas. Comparing the aliasing component distribution shown in FIG. 3 and the frequency characteristics in FIG. 6, we can see that aliasing components e and f due to field offset subsampling included in the video signal during still images can be removed by field comb filter processing. It can be seen that it exists within the range of NULL. That is, by performing this field comb filter processing, it is possible to remove aliasing components caused by field offset subsampling included in a video signal at the time of a still image. Therefore, Figure 7 (
The system shown in FIG. 1 has a configuration in which signal processing similar to the block diagram of the field comb filter shown in 1) is realized at the output section of the EDTV processor 105.

FIG. 8 shows the structure of a video signal including aliasing components resulting from 525/60 field offset subsampling output from the EDTV processor 105. In FIG. 8, the vertical axis represents the vertical direction, the horizontal axis represents the time direction, and A, B, and C in the figure each represent a video signal (scanning line). It is now assumed that the EDTV processor 105 has obtained a video signal A in the figure and a motion detection signal synchronized therewith. The above EDTV processor 105
The video signal A obtained from the line memory 107 has a capacity for two lines, and the line memory 1 has a capacity for one line.
Enter 08. The adder 109 receives the video signal A and the video signal C delayed by two lines by the line memory 107.
are input and averaged to obtain a video signal of the current field of (A+C)/2. The line memory 108 is the EDTV mentioned above.
A video signal B which is one line delayed from the video signal A obtained from the processor 105, that is, a video signal delayed by one field from the video signal A by the scanning line interpolation process of the EDTV processor 105 is obtained. The adder 110 receives the current field video signal ((A+C)
/2) and a video signal delayed by one field with respect to the current field video signal obtained from the line memory 108 are input and averaged. In other words, this process is shown in Figure 7 (1) above.
) corresponds to the field comb filter processing shown in (). Therefore, the video signal output from the adder 110 has the following characteristics as shown in FIG.
Based on the principle shown in , aliasing components due to field offset subsampling are not included. FIG. 9 is a diagram showing the frequency components that can be removed by the above-mentioned signal processing (field comb filter processing and frame comb filter processing of the EDTV processor 105) together with the aliasing component distribution diagram for still images in FIG. 3. be. That is, as shown in FIG. 9, at this point, a video signal can be obtained from which aliasing components (FIGS. 3a, b, c, d, e, f) included in the still image video signal are removed.

The mixing processing circuit 111 combines the 525/60 video signal obtained from the adder 110 from which aliasing components of the still image have been removed and the 525/6 video signal obtained from the EDTV processor.
0 video signal is input and mixed and output according to the motion detection signal obtained from the EDTV processor.

The input signal selection means 112 inputs the 525/60 converted MUSE signal output from the mixing processing circuit 111 and the 525/60 video signal obtained from the EDTV processor, and the user wishes to view the video content of the MUSE signal. Sometimes, the video signal output from the mixing processing circuit 111 is output from the EDTV when the standard NTSC signal is to be viewed.
Selectively outputs the video signal obtained from the processor.

According to the configuration shown in FIG.
By using a /NTSC down converter and an EDTV processor and adding a line memory for 3 lines to them, it is possible to completely remove aliasing components due to frame offset subsampling and field offset subsampling of the encoder.

Although the overall configuration and signal processing principles of one embodiment of the present invention have been described above, the present invention is not limited to the above-described configuration. For example, instead of processing equivalent to a field comb filter using the above-mentioned 3-line line memory configuration, line sum processing is performed using a configuration using a 1-line line memory and an adder to perform almost the same processing equivalent to a field comb filter. It is also possible to realize this.

Next, another embodiment of the present invention will be described. FIG. 10 is a diagram showing still another embodiment of the present invention. In FIG. 10, components denoted by the same reference numerals as those in FIG. 1 perform the same operations. The difference between the system shown in Figure 10 and the system shown in Figure 1 is that the line memory used for signal processing equivalent to field comb filter processing is configured in a position before conversion to a 525/60 double speed signal. This is a characteristic configuration of this embodiment. 1
0 is a frame correlation processing means, 1001 is a motion adaptive type Y
a motion adaptive Y/C separation circuit that performs /C separation and further outputs a motion detection signal; 1002 is a line memory;
3 is an adder, 1004 is a field memory, 1005 is a mixing processing circuit, 1006 and 1007 are line memories, 1
008, 1009, 1010, 1011 are adders, 10
12 and 1013 are mixing processing circuits, 1014 and 1015 are input signal selection circuits, and 1016 is a double speed conversion processing circuit.

Next, the operation of the circuit shown in FIG. 10 will be explained using FIG. 11. Figure 11 shows the structure of a 525/30 NTSC signal, where the vertical axis indicates the vertical direction, the horizontal axis indicates the time direction, and A, B, C, D, and E in the figure are video signals (scanning lines). ) means. First, a case will be described in which the input signal selection circuit 104 selects and outputs the standard 525/30 NTSC signal output from the input terminal 102.

The motion adaptive Y/C separation circuit 1001 performs motion adaptive Y/C separation and motion detection on the standard NTSC signal output from the input signal selection circuit 104 according to the principle shown in FIG. The video signal output from the motion adaptive Y/C separation circuit 1001 is sent to the line memory 1002.
and input into field memory 1004. Line memory 1002 delays the input video signal by one line, adder 1003, line memory 1006, adder 1008
Output to. Assume that the video signal output from this line memory 1002 is A in FIG. An adder 1003 averages the video signal output from the motion adaptive Y/C separation circuit 1001 and the video signal output from the line memory 1002 to create a video signal for average interpolation. Field memory 1004 includes the motion adaptive Y/C separation circuit 100.
The video signal output from 1 is delayed by one field to create a video signal for inter-field interpolation. The mixing processing circuit 1005 inputs the video signal for average interpolation and the video signal for interfield interpolation, mixes and outputs the video signal according to the motion detection signal output from the motion adaptive Y/C separation circuit 1001, and performs interpolation scanning. Create a line video signal. Assume that the video signal output from this mixing processing circuit 1005 is D in FIG. Further, the video signal (D in FIG. 11) output from this mixing processing circuit 1005 is sent to an input signal selection circuit 10, which will be described later.
14 and is selected and output to the output terminal 106 and the double speed conversion circuit 1016. Here, the video signal outputted from the output terminal 106 is a high-quality 525/30 video signal that has been subjected to motion adaptive Y/C separation processing. The line memory 1006 delays the video signal (A in FIG. 11) output from the line memory 1002 by one line to obtain the video signal in FIG. 11B. The video signal (B in FIG. 11) output from this line memory 1006 is transmitted to the input signal selection circuit 1, which will be described later.
015 and is selected and output to the double speed conversion circuit 1016. The double speed conversion circuit 1016 converts the video signal (standard NTSC signal) subjected to the above-described high image quality signal processing to double speed, that is, 525/60, and outputs it to the output terminal 113. Next, the input signal selection circuit 104
A case will be explained in which the MUSE/NTSC down converter 103 selects and outputs a 525/30 NTSC signal including an aliasing component.

When the 525/30 NTSC signal containing the aliasing component output from the MUSE/NTSC down converter 103 is input to the motion adaptive Y/C separation circuit, that is, the motion adaptive frame comb filter processing circuit, it is processed according to the principle shown in FIG. Folding components due to frame offset subsampling during still images are removed. Therefore,
The remaining aliasing components due to field offset subsampling are removed by signal processing corresponding to the principle of FIG. 7, that is, field comb filter processing.

Line memory 1006 delays the video signal (FIG. 11A) output from line memory 1002 by one line (FIG. 11B) and outputs it to adder 1008. The adder 1008 inputs the video signal outputted from the line memory 1002 (FIG. 11A) and the video signal outputted from the line memory 1006 (FIG. 11B), and calculates the arithmetic average ((A+B).
)/2) to obtain the video signal of the current field. Adder 1
In 009, the video signal ((A+B)/2) outputted by the adder 1008 and the video signal outputted by the mixing processing circuit 1005 (FIG. 11D), that is, the adder 1008
Input the video signal that is delayed by one field with respect to the video signal output by
)/2)) to obtain a video signal at the center of gravity position D. That is, this processing corresponds to the field comb filter shown in FIG. 7(1) above. Accordingly, the video signal output from the adder 1009 does not include aliasing components due to field offset subsampling based on the principle shown in FIG. The mixing processing circuit 1012 combines the video signal of the gravity center position D output from the adder 1009 and the mixing processing circuit 1005.
A video signal (FIG. 11D) output from the motion adaptive Y/C separation circuit 1001 is input and mixed and output according to the motion detection signal output from the motion adaptive Y/C separation circuit 1001. Input signal selection processing circuit 1014
When you want to see the video content of the MUSE signal, the mixing processing circuit 1012 outputs the video signal from which the aliasing component at the time of a still image has been completely removed, and when you want to see the standard NTSC signal, the mixing processing circuit 1005 outputs the video signal. Selectively output signals.

Line memory 1007 delays the video signal (FIG. 11D) output from mixing processing circuit 1005 by one line (FIG. 11E) and outputs it to adder 1010. The adder 1010 inputs the video signal output from the line memory 1007 (FIG. 11E) and the video signal output from the mixing processing circuit 1005 (FIG. 11D), and calculates the arithmetic average ((D+E).
)/2) to obtain a video signal delayed by one field. The adder 1011 combines the video signal ((D+E)/2) output from the adder 1010 and the line memory 10.
The video signal outputted by 06 (FIG. 11B), that is, the video signal of the current field, is inputted and averaged (((D+E)/2
)+B)/2)) to obtain a video signal at the center of gravity position B. That is, this processing corresponds to the field comb filter shown in FIG. 7(1) above. Therefore, the video signal output from the adder 1011 does not include aliasing components due to field offset subsampling based on the principle shown in FIG. The mixing processing circuit 1013 is the adder 1011
The video signal at the center of gravity position B output from the line memory 1006 and the video signal (FIG. 11B) output from the line memory 1006 are input and mixed and output according to the motion detection signal output from the motion adaptive Y/C separation circuit 1001. When the input signal selection processing circuit 1015 wants to see the video content of the MUSE signal, the video signal output from the mixing processing circuit 1013, from which aliasing components at the time of a still image have been completely removed, is converted into a standard NTSC signal.
When a signal is desired to be viewed, the video signal output from the line memory 1006 is selected and output. Double speed conversion circuit 1016
is the 525/30 video signal output from the input signal selection circuits 1014 and 1015 at double speed, that is, 525/6.
0 video signal and output it to the output terminal 113.

According to the configuration shown in FIG. 10, compared to the configuration shown in FIG. 1, the line memory used for signal processing equivalent to field comb filter processing is configured at a position before conversion to a 525/60 double speed signal. By doing so, it is possible to completely eliminate the aliasing components caused by the encoder's frame offset subsampling and the aliasing components caused by field offset subsampling, as in Figure 1, while reducing the line memory operating speed to 1/2 and the memory capacity to 2/3. becomes.

Further, the motion detection signals necessary for the mixing processing circuits 1012 and 1013 may be signals having a speed corresponding to a 525/30 video signal, and it is possible to use the same signal as that for the mixing processing circuit 1005, which differs only in delay time. This also has the effect of simplifying the circuit system that generates the motion detection signal.

FIG. 12 is a diagram showing still another embodiment of the present invention. In FIG. 12, the same reference numerals as in FIGS. 1 and 10 above perform the same operations. The difference between the system shown in Figure 12 and the system shown in Figure 10 is
This embodiment is characterized by the fact that the line memory used for signal processing equivalent to field comb filter processing is arranged in front of the mixing processing circuit 1005 for creating scanning line interpolation signals. 1201, 1204, 1
205 is an adder, 1202 and 1207 are input signal selection circuits, 1203 is a line memory, and 1206 is a mixing processing circuit.

Next, the operation of the circuit shown in FIG. 12 will be explained using FIG. 13. Figure 13 shows the structure of a 525/30 NTSC signal, where the vertical axis represents the vertical direction, the horizontal axis represents the time direction, and A, B, C, and D in the figure each represent the video signal (scanning line). means. In addition, A in the figure is the motion adaptation Y/
C is an incoming video signal outputted from the separation circuit 1001; B is a video signal delayed by one field with respect to the incoming video signal A outputted from the field memory 1004; C is a video signal delayed by one line with respect to the incoming video signal A by the line memory 1002; This is a delayed video signal. First, input signal selection circuit 1
04 selects and outputs the 525/30 standard NTSC signal output from the input terminal 102.

The input signal selection circuit 1202 selects the video signal (FIG. 13B) for scanning line interpolation in still images outputted from the field memory 1004 and sends it to the mixing processing circuit 1005.
Output to. The input signal selection circuit 1207 selects the video signal (FIG. 13C) output from the line memory 1002 and outputs it to the double speed conversion circuit 1016 and the output terminal 106. The double speed conversion circuit 1016 converts the video signal (standard NTSC signal) subjected to the above signal processing into double speed, that is, 525/
60 and outputs it to the output terminal 113. Next, the input signal selection circuit 104 selects the MUSE/NT
A case where the SC down converter 103 selectively outputs a 525/30 NTSC signal including an aliasing component will be described.

When the 525/30 NTSC signal containing aliasing components output from the MUSE/NTSC down converter 103 is input to the motion adaptive Y/C separation circuit 1001, that is, the motion adaptive frame comb filter processing circuit, the signal shown in FIG. According to the principle, aliasing components due to frame offset subsampling during still images are removed. Therefore, the remaining aliasing components due to field offset subsampling are removed by performing signal processing corresponding to the principle of FIG. 7, that is, field comb filter processing.

The adder 1201 receives the video signal output from the adder 1003 ((A+C)/2 in FIG. 13, that is, the video signal of the current field) and the field memory 100.
The video signal outputted from 4 (B, that is, the adder 100
A video signal that is delayed by one field with respect to the video signal output from 3) is input, and the average is (((A+C)/2
)+B)/2)) to obtain a video signal at the center of gravity position B, and output it to the input signal selection circuit 1202. That is, this processing corresponds to the field comb filter shown in FIG. 7(1) above. Therefore, the video signal output from the adder 1201 does not include aliasing components due to field offset subsampling based on the principle shown in FIG. The line memory 1203 delays the video signal at the center of gravity position B output from the field memory 1004 by one line (FIG. 13D).
(the center of gravity position) and outputs it to the adder 1204. Adder 1
204 inputs the video signal output from the line memory 1203 (FIG. 13D) and the video signal output from the field memory 1004 (FIG. 13B) and averages the video signal ((B+D)/2 in FIG. 13). obtain. Adder 1
205 is a video signal outputted from the adder 1204 ((B+D)/2 in FIG. 13, that is, a video signal of a field delayed by one field from the current field in which video signal A exists) and a video signal outputted from the line memory 1002 ( C in FIG. 13 (that is, the video signal of the current field) is inputted and averaged (((B+D)/2)+C)/2)) to obtain the video signal at the center of gravity position C. That is, this processing corresponds to the field comb filter shown in FIG. 7(1) above. Therefore, the video signal output from the adder 1011 does not include aliasing components due to field offset subsampling based on the principle shown in FIG. The mixing processing circuit 1206 inputs the video signal at the center of gravity position C output from the adder 1205 and the video signal (FIG. 11C) output from the line memory 1002, and performs motion detection to output from the motion adaptive Y/C separation circuit 1001. Mixed output according to the signal. The input signal selection processing circuit 1207
If you want to view the video content of the signal, select the video signal output from the mixing processing circuit 1206 with the aliasing component at the time of a still image completely removed, and if you want to view the standard NTSC signal, select the video signal output from the line memory 1002. Output. The double speed conversion circuit 1016 outputs 525/3 from the input signal selection circuits 1202 and 1207.
The video signal of 0 is converted into a video signal of double speed, that is, 525/60, and outputted to the output terminal 113.

According to the configuration shown in FIG. 12, compared to the configuration shown in FIG. 10, the line memory used for signal processing corresponding to field comb filter processing is placed in front of the mixing processing circuit 1005 for creating the scanning line interpolation signal. With this configuration, it is possible to completely eliminate the aliasing components caused by the frame offset subsampling and the aliasing components caused by the field offset subsampling of the encoder, as in FIG. 1, while reducing the capacity of the line memory to 1/2.

[0040]

According to the present invention, in an apparatus for receiving a high-definition television signal and a standard television signal and converting the signals into the NTSC system or EDTV system, field offset sub-setting is performed by the encoder when the high-definition television signal is input. It is possible to completely eliminate aliasing interference that is theoretically generated by sampling processing and frame offset subsampling processing with a simple circuit configuration.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing a conventional example.

FIG. 3 is an explanatory diagram illustrating the principle of the present invention;
FIG. 3 is a diagram showing a still image and repeating component distribution of an E signal.

FIG. 4 is an explanatory diagram explaining the principle of the present invention, (1)
is the frequency characteristic of the two-dimensional filter, and (2) is the frequency characteristic of the two-dimensional filter viewed from the horizontal-vertical plane.

FIG. 5 is a diagram for explaining the operating principle of the present invention, and N
FIG. 3 is a diagram showing the structure of a TSC signal.

FIG. 6 is an explanatory diagram illustrating the principle of the frame comb filter of the present invention, and shows the frequency characteristics of the frame comb filter.

FIG. 7 is an explanatory diagram illustrating the principle of the field comb filter of the present invention, in which (1) is a general block diagram of the field comb filter, and (2) is the frequency characteristic of the field comb filter.

FIG. 8 is an explanatory diagram illustrating the principle of the present invention, and
3 is a diagram showing the structure of a video signal output from a V processor 105. FIG.

FIG. 9 is a diagram collectively showing frequency components that can be removed by the field and frame comb filters of the present invention.

FIG. 10 is a configuration diagram showing a second embodiment of the present invention.

FIG. 11 is an explanatory diagram illustrating the operating principle of a second embodiment of the present invention.

FIG. 12 is a configuration diagram showing a third embodiment of the present invention.

FIG. 13 is an explanatory diagram illustrating the operating principle of a third embodiment of the present invention.

[Explanation of symbols]

101, 102...Input terminal, 103...MUSE/NTSC down converter, 104
, 112... Input signal selection processing circuit, 105... EDTV processor, 106... Output terminal, 107, 108... Line memory, 109, 110... Adder, 111... Mixing processing circuit, 112... Speed conversion processing circuit, 113... Output terminal , 1001...Motion adaptive Y/C separation circuit, 1002...Line memory, 1003...Adder, 1004...Field memory, 1005, 1012, 1013...Mixing processing circuit, 100
6, 1007... Line memory, 1008, 1009, 1010, 1011... Adder, 1
014, 1015... Input signal selection circuit, 1016... Double speed conversion circuit, 1201, 1204, 1205... Adder, 1202, 1
207...Input signal selection circuit, 1206...Mixing processing circuit

Claims (4)

[Claims] Claim 1. An apparatus for receiving a high-definition television signal transmitted using a multiple subsample band compression method, which performs intra-field signal processing on the received high-definition television signal to provide a standard speed scan television signal. (hereinafter referred to as the NTSC system); and a motion-adaptive high image quality that utilizes frame correlation for the video signal that uses the NTSC system and is output from the first down-conversion means. EDTV processor means for converting the video signal into a double-speed scanning television format (hereinafter referred to as EDTV format) video signal by performing a conversion process and simultaneously outputting a motion detection signal; and an EDTV video video output from the EDTV processor means. a first line memory means for inputting and delaying a signal; a first line memory means for inputting and averaging the video signal outputted from the first line memory means and the video signal adopting the EDTV system outputted from the EDTV processor means; an adding means; a first adding means for inputting the video signal outputted from the first adding means and the video signal employing the EDTV system outputted from the EDTV processor means, and mixing and outputting the video signal according to the motion detection signal outputted from the EDTV processor means; 1 mixing means;
A television signal reception and processing device characterized in that aliasing components are removed using a multiple subsample band compression method. 2. Receiving a television signal according to claim 1;
In the processing device, an input means for inputting a standard television signal, a video signal from the input means and a video signal adopting the NTSC system output from the first down-converting means are inputted and selectively output to the EDTV processor means. a first input signal selection means for inputting and selectively outputting the video signal output from the first mixing means and the video signal adopting the EDTV system output from the EDTV processor means; What is claimed is: 1. A television signal receiving and processing device, characterized in that it is capable of processing standard television signals and high-definition television signals. 3. An apparatus for receiving a high-definition television signal and a standard television signal, which performs in-field signal processing on the received high-definition television signal.
a second down-converting means for converting into a signal adopting the SC system, and a third input inputting and selectively outputting the received standard television signal and the video signal adopting the NTSC system outputted from the second down-converting means. signal selection means; and NTSC output from the third input signal selection means.
Frame correlation processing that outputs a 525/30 incoming video signal, a 525/30 scanning line interpolation video signal, and a motion detection signal, which performs motion-adaptive high-quality processing using frame correlation on the video signal that adopts this method. means, second line memory means for inputting and delaying the 525/30 incoming video signal output from the frame correlation processing means, and a video signal output from the second line memory means and the video signal output from the frame correlation processing means. a second addition means that inputs and averages the 525/30 incoming video signal to be output; and a third line memory that delays the 525/30 scanning line interpolation video signal output from the frame correlation processing means. a third adding means for inputting and averaging the video signal output from the third line memory means and the 525/30 scanning line interpolation video signal output from the frame correlation processing means; a fourth adding means which receives and averages the video signal outputted from the second adding means and the 525/30 scanning line interpolation video signal outputted from the frame correlation processing means; a fifth adding means for inputting and averaging the video signal to be outputted and the video signal outputted from the second line memory means; and a video signal outputted from the fourth adder and outputted from the frame correlation processing means. a second mixing means for inputting a 525/30 scanning line interpolation video signal and mixing and outputting the same in accordance with a motion detection signal output from the frame correlation processing means;
fourth input signal selection means for inputting and selectively outputting the video signal output from the mixing means and the 525/30 scanning line interpolation video signal output from the frame correlation processing means;
Third mixing means inputs the video signal outputted from the fifth addition means and the video signal outputted from the second line memory means, and mixes and outputs the video signal outputted from the frame correlation processing means according to the motion detection signal outputted from the frame correlation processing means. and a fifth input signal selection means for inputting and selectively outputting the video signal output from the third mixing means and the video signal output from the second line memory means, and the fifth input signal selection means. and a first double-speed converting means for inputting the video signal outputted from the input signal selection means and the video signal outputted from the fourth input signal selection means, and converting the received video signal into a video signal adopting the EDTV system. John signal reception and processing device. 4. An apparatus for receiving a high-definition television signal and a standard television signal, which performs in-field signal processing on the received high-definition television signal.
a third down-converting means for converting into a signal adopting the SC system, and a sixth input inputting and selectively outputting the received standard television signal and the video signal adopting the NTSC system outputted from the third down-converting means. signal selection means; and NTSC output from the sixth input signal selection means.
a frame comb processing means for outputting a 525/30 video signal and a motion detection signal, which are subjected to motion adaptive high image quality processing using frame correlation on the video signal adopting the method; and an output from the frame comb processing means. a fourth line memory means for inputting and delaying a video signal to be processed; and a sixth line memory means for inputting and averaging the video signal outputted from the fourth line memory means and the video signal outputted from the frame combing processing means. an addition means, a first field memory means for delaying the video signal output from the frame comb processing means, a video signal output from the first field memory means and a video signal output from the sixth addition means; a seventh addition means for inputting and averaging; and a seventh input signal selection means for inputting and selectively outputting the video signal output from the seventh addition means and the video signal output from the frame memory means; , a fourth input signal inputting the video signal output from the seventh input signal selection means and the video signal output from the sixth addition means, and mixing and outputting the video signal according to the motion detection signal output from the frame comb processing means. a fifth line memory means for delaying the video signal output from the first field memory means; and a video signal output from the fifth line memory means and an output from the first field memory means. an eighth adding means which inputs and averages the video signal to be inputted, and a ninth adding means which inputs and averages the video signal outputted from the eighth adding means and the video signal outputted from the fourth line memory means; an adding means for inputting the video signal outputted from the ninth adding means and the video signal outputted from the fourth line memory means and mixing and outputting the video signal according to the motion detection signal outputted from the frame correlation processing means. an eighth input signal selection means for inputting and selectively outputting the video signal output from the fifth mixing means and the video signal output from the fourth line memory means; It is characterized by comprising a second double-speed conversion means that inputs the video signal outputted from the signal selection means and the video signal outputted from the fourth mixing processing means and converts it into a video signal adopting the EDTV system. equipment for receiving and processing television signals.