JPH04180391A - Video signal conversion device - Google Patents

Abstract

PURPOSE:To reduce the scale of a hardware in an interpolation processing part in a video conversion device by simultaneously performing the interpolation processing to a luminance signal and color difference signal by means of a filter composed of four line memories. CONSTITUTION:An analog MUSE signal inputted to an input terminal 1 is converted into a digital signal by an A/D converter 2, inputted to a non-linear deemphasis filter 3 so as to perform restoration. Then, the interpolation processing from a sample point in a field of non-sample point of a video signal sub-sampled in an interfield interpolation processing circuit 4 is performed. Thus, by simultaneously performing the interpolation processings separately performed for the conventional luminance signal Y and color difference signals R-T and B-Y by means of the filter with one construction, the scale of the hardware in the interfield interpolation processing part in the conventional video signal conversion device can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention converts high-definition television signals, which have been transmitted with bandwidth compression using a sub-sampling transmission method, into the current standard television signal (hereinafter referred to as NTSC television signal). The present invention relates to a video signal conversion device for converting a signal into a standard television signal (abbreviated as a standard television signal).

2. Description of the Related Art In recent years, high-definition television (also referred to as high-definition television) has been experimentally broadcast using broadcasting satellites, and has also been adopted in various ways in the video industry using closed circuits.

High-definition television signals have a frequency bandwidth of N
This method has a frequency bandwidth of 20 MHz, which is approximately five times that of the TSC method, and it is
Hz), a method of compressing the signal band using multiple sub-Nyquist sampling (
Television Society Technical Report “High Definition Television Satellite 1”
Channel transmission method” (MUSE) TEBS 95
-2 VOL7 No.

44) has been proposed.

This MUSE method performs offset sampling between fields and frames, and is a method of transmitting images by performing processing such that the sampling phase completes one cycle in two frames, that is, four frames. The MUSE method is not compatible with the current NTSC method, and the MUSE method is not compatible with the current NTSC method.
In order to restore the signal transmitted by the SE method to the original image, a dedicated signal processing circuit (referred to as a MUSE decoder) is required. However, MUSE decoders are generally very expensive, and it is thought that it will take a considerable amount of time for them to become widespread for home use. Therefore, it is conceivable to convert the video signal so that the high-definition television signal can be received by the current standard television receiver or video tape recorder that is currently widespread in homes.

Conventionally, as this type of video signal conversion device, for example, r
MUSE/NTSC Converter” Electronic Technology 1989-4
is shown.

FIG. 11 shows a block diagram of the conventional video signal converter, and in the figure, the MUSE signal is connected to input terminal 1.
An A/D converter 102 input from 01 and converting the input analog signal into a digital signal, a nonlinear de-emphasis filter 103 for restoring the nonlinear emphasis characteristic applied when FM transmitting the MUSE signal, and high quality. A time base conversion circuit 104 for converting a television signal into a current standard television signal, and Y of each converted standard television signal.

After passing through a vertical low-pass filter 105.106.107 for the R-Y and B-Y signals, the signal passes through a D/A converter 108.109.110 for converting each digital signal into an analog signal. It is configured to output Y, RY, and BY signals converted into standard television signals from output terminals 111.112.113.

FIG. 12 is a block diagram showing the configuration of the Y vertical filter 105 in FIG. 11. In FIG. 12, the Y signal converted to a standard television signal is input to an input terminal 114 and applied to one-line delay circuits 115 and 116. Here, a multiplier 117.1/2 whose gain changes to 3/8 when processing an odd field and 1/8 when processing an even field.
A multiplier 118 with a gain of 1/1 when processing an odd field.
8. The signal is configured to be outputted from an output terminal 122 after passing through a multiplier 119 whose gain changes to 3/8 during even field processing and adders 120 and 121.

FIG. 14(a) is a block diagram showing the configuration of the RY vertical filter 106 in FIG. 11, and FIG. 14(b) is a block diagram showing the configuration of the BY vertical filter 107 in FIG. 1st
In FIG. 4(a), the color difference signal R-Y of the time-compressed standard television signal is inputted to an input terminal 123, and passes through a time expansion circuit 124 for stretching the input color difference signal in the time direction. 1 line delay circuit 125,
After passing through a multiplier 127 having a gain of 126.1/2, it is output from an output terminal 128. Also, the 14th
In the figure (b), the color difference signal B-Y of the time-compressed standard television signal is input to the input terminal 129,
The input color difference signal is passed through a time expansion circuit 130 for stretching it in the time direction, and then passed through a one-line delay circuit 131.1.
32, adder 133, and multipliers 134 and 136 with a gain of 135.1/2, and then output from an output terminal 137.

The operation of the conventional video signal converter configured as described above will be described below. In FIG. 11, an analog MUSE signal input to an input terminal 101 is converted into a digital signal by an A/D converter 102. The MUSE signal converted into a digital signal is input to a nonlinear de-emphasis filter 103. Here, in the non-linear de-emphasis filter 103, processing is performed to restore the non-linear emphasis characteristic applied when the MUSE signal is FM-modulated and transmitted. Next, the time axis conversion circuit 104 performs time axis conversion to convert the high-definition television signal to the current standard television signal, and converts the Y and time compressed R-Y
, B-Y signals. Separated Y, R
-Y, B-Y signals are Y vertical filter 105, R
-Y vertical filter 106 and B-Y vertical filter 107, and are each subjected to vertical band limitation.

In the Y vertical filter, the Y signal is provided to input terminal 114 in FIG. The signal is then input to a 1-line delay circuit 115, and its output is further input to a 1-line delay circuit 116. The input Y signal is also multiplied by the multiplier 117 to 378 when processing an odd field, and to 1/8 when processing an even field.
The gain is adjusted accordingly. The output of the l-line delay circuit 115 is multiplied by 1/2 in gain by a multiplier 118. The gain of the output of the one-line delay circuit 116 is adjusted by a multiplier 119 to 1/8 when processing an odd field, and to 3/8 when processing an even field. Said multiplier 117.118.1
The outputs of 19 are all added by adders 120 and 121,
It is output from the output terminal 122. In other words, the Y vertical filter shown in FIG. 12 performs (1/
It operates as a 3-tap vertical filter with coefficients of 8.1/2.3/8), and when processing even fields it operates as a 3-tap vertical filter with coefficients of (3/8.
It operates as a 3-tap vertical filter with coefficients of 1/2.1/8). When this Y vertical filter is used, the center of gravity of the scanning line of the luminance signal is as shown in FIG.

Next, in the R-Y vertical filter, the time-compressed R-
The Y signal is supplied to the input terminal 123 in FIG. 14(a). Next, the signal is expanded to the original time axis in the time expansion circuit 124 and inputted to the 1-line delay circuit 125. Adder 1
At 26, the current pixel data and the image data delayed by one line are added, and after the gain is multiplied by 1/2 at a multiplier 127, the data is output from an output terminal 128. That is, the first
The R-Y vertical filter shown in Figure 4(a) has (1
A 2-tap filter with a coefficient of /2.1/2) is formed. On the other hand, in the B-Y vertical filter, the R-Y signal is stretched to the original time axis in the zero-order time expansion circuit 130 supplied to the input terminal 129 of FIG. 131. The output of the 1-line delay circuit 131 is further input to the 1-line delay circuit 132. The adder 133 adds the current pixel and the pixel delayed by two lines, and the multiplier 134 adds the gain to 1/2.
be multiplied. Furthermore, the output of the multiplier 134 and the output of the 1-line delay circuit 131 are added in an adder 135,
After the gain is multiplied by 1/2 by the multiplier 136, the output terminal 1
37. That is, the BY vertical filter shown in FIG. 14(b)
/4) to form a 3-tap filter. When these R-Y vertical filters or B-Y vertical filters are used, the center of gravity of the scanning line of the color signal is as shown in FIG.

In FIG. 11, the outputs of the vertical filters 105, 106, 107 for the Y, RY, and BY signals are respectively converted from digital signals to analog signals by D/A converters 108, 109, 110. Later, standard television signals Y, R-Y.

Output terminals 111, 112゜1 as B-Y signals respectively
13.

Problems to be Solved by the Invention In such a conventional configuration, the video signal that has passed through the time axis conversion circuit 104 is divided into a luminance signal Y and color difference signals R-Y, B-Y.
The luminance signal Y is separated into a Y vertical filter 105, and the color difference signal R-Y.

R-Y vertical filters 106 for B-Y, respectively;
Since the B-Y vertical filter 107 is individually adapted to perform interpolation processing in the vertical direction, there is a problem in that the hardware scale of the interpolation processing section increases.

The present invention solves the above-mentioned problem, and by performing interpolation processing, which was conventionally performed separately for luminance signals and color difference signals, using a single filter, it is possible to improve the field It is an object of the present invention to provide a video signal conversion device that realizes a reduction in the hardware scale of an interpolation processing section.

Means for Solving the Problems In order to achieve the above object, the present invention inputs a high-definition television signal band-compressed by offset subsampling, and extracts samples in the field in order to restore the subsampled signal. Intra-field interpolation means for interpolating non-sampled points from points; time-axis conversion means for converting the number of scanning lines into a standard television signal of progressive scanning; and interpolation processing for color difference signals thinned out line-sequentially. First thing to do. line-sequential interpolation means for obtaining a second color difference signal, and the intra-field interpolation means includes a first horizontal period delay element;
The second one continues in tandem with it. third and fourth horizontal period delay elements; interpolation means for performing interpolation processing of a color difference signal from the input signal, the output signal of the second delay element, and the output signal of the fourth delay element; and a first delay element. Interpolation means for interpolating a luminance signal from the output signal of the element, the output signal of the second delay element, and the output signal of the third delay element, and time expansion means for restoring the time-compressed color difference signal. A video signal conversion device characterized by comprising:

Furthermore, the present invention inputs a high-definition television signal band-compressed by offset subsampling, and includes an intra-field interpolation means for interpolating non-sampled points from sampled points in the field in order to restore the subsampled signal. ,
a time axis converting means for converting the number of scanning lines into a standard television signal of progressive scanning or interlaced scanning, and a progressive scanning television signal when the time axis converting means converts the number of scan lines into a standard television signal of progressive scanning; and means for thinning out scanning lines from an interlaced television signal, and the intra-field interpolation means includes a first horizontal period delay element and a second horizontal period delay element cascaded therewith. Third. Fourth
a horizontal period delay element; an interpolation means for interpolating a luminance signal from the output signal of the first delay element, the output signal of the second delay element, and the output signal of the third delay element; interpolation means for interpolating the first color difference signal from the output signal of the second delay element and the output signal of the fourth delay element; and the output signal of the first delay element and the output of the third delay element. interpolation means for interpolating the second color difference signal from the signal; The first chrominance signal for restoring the second color difference signal. the second time expansion means; and the restored first . By alternating the second color difference signal for each line, each color difference signal R-Y is generated.
.

This is a video signal conversion device characterized by comprising a switching means for obtaining B-Y.

Operation The present invention uses the above-described first configuration to convert the luminance signal Y and color difference signal RY of the conventional MUSE signal.

By performing interpolation processing that was previously performed individually on B-Y simultaneously using a single filter configuration, it is possible to reduce the hardware scale of the intra-field interpolation processing section in conventional video signal conversion equipment. It is something.

Furthermore, the present invention has a configuration in which line-sequential interpolation processing is simultaneously performed on color difference signals that are thinned out line-sequentially and transmitted in accordance with the MUSE signal standard, using the second configuration described above. By including it in the interpolation means, the luminance signal Y and the color difference signal R-
Interpolation processing of Y and B-Y can be performed to eliminate the need for line-sequential interpolation processing after time axis conversion in the first configuration. In addition, when only video signal conversion from the MUSE signal to an interlaced standard television signal is required, the time axis conversion means to the progressive scanning standard television signal in the second configuration may be replaced with an interlaced standard television signal. By substituting the time axis conversion means for the television signal, the memory capacity of the time axis conversion means can be reduced and the line alternation switching means in the intra-field interpolation processing section can be made unnecessary.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a video signal converter according to a first embodiment of the present invention. In Figure 1, M
A USE signal is input from an input terminal 1, and an A/D converter 2 converts the input analog signal into a digital signal;
A non-linear de-emphasis filter 3 is used to restore the non-linear emphasis characteristic applied during FM transmission of the MUSE signal. An intra-field interpolation processing circuit 4 performs interpolation processing from a point, a time axis conversion circuit 5 converts the number of scanning lines of a high-definition television signal to the number of scanning lines of a standard television signal of sequential scanning, and a line-sequential A line-sequential interpolation processing circuit 6 that performs interpolation processing on the thinned and transmitted color difference signal, and a line-sequential interpolation processing circuit 6 that performs interpolation processing on the thinned and transmitted color difference signal;
/A converter 7, each of which is converted into a progressively scanned standard television signal.

The R-Y and B-Y signals are output from output terminals 8, 9.10. It also passes through a scanning line conversion circuit 11 that thins out scanning lines from a progressive scanning television signal to an interlaced scanning television signal, and a D/A converter 12 that converts an interlaced scanning digital standard television signal into an analog signal. Later, Y of interlaced standard television signals.

The R-Y, B-Y signals are taken out from the output terminals 13.14.15.

FIG. 2 is a block diagram showing the configuration of the intra-field interpolation processing circuit 4 in FIG. 1. In Figure 2, MUS
The E signal is input to the input terminal 21, and is input to the 1-line delay memory 22, 23, 24, 25, 3/3 during even field processing.
8. Multiplier 26 whose coefficient changes to 5/8 when processing an odd field; multiplier 27 whose coefficient changes to 1/4 when processing an even field; and 3/4 when processing an odd field; 3/4 when processing an even field; Multiplier 28 whose coefficient changes to 1/4 when processing an odd field, 578 when processing an even field,
Multiplier 2 whose coefficient changes to 3/8 when processing odd fields
9. Adder 30. Multiplier 32 with coefficients of 31.1/2.
, 33, and a color difference signal time axis expansion circuit 34, and the luminance signal interpolated within the field is output to an output terminal 35.
The configuration is such that the color difference signal outputted from the field and subjected to intra-field interpolation is taken out from the output terminal 36.

The operation of the video signal converter according to the embodiment of the present invention configured as described above will be described below.

First, an analog MUSE signal input to the input terminal 1 is converted into a digital signal by the A/D converter 2. The MUSE signal converted into a digital signal is input to the nonlinear de-emphasis filter 3. In the non-linear de-emphasis filter 3, the video signal sub-sampled in the zero-order intra-field interpolation processing circuit 4 is processed to restore the non-linear emphasis characteristic applied when transmitting the MUSE signal after FM modulation. An interpolation process is performed from the sample points in the field of non-sample points.

The intra-field interpolation processing circuit 4 will be explained using FIG. The MUSE signal is supplied to input terminal 21.

The input signal is transmitted through four 1-line delay circuits 22 connected in cascade.
．． It is input sequentially on 23, 24, and 25. A portion of the signal branched from the input signal is supplied to the adder 31 after the multiplier 26 adjusts the gain to 5/8 when processing an odd field and to 3/8 when processing an even field. Also, part of the signal input from the input terminal 21 is transferred to the 1-line delay circuit 2.
2 and branched from its output is added to multiplier 27
The gain is adjusted to 3/4 during odd field processing, and to 1/4 during even field processing, and then supplied to the adder 30. A signal branched from the output of the one-line delay circuit 23 is supplied to an adder 30 and an adder 31.

The signal branched from the output of the 1-line delay circuit 24 is adjusted in gain to 1/4 when processing odd fields and to 3/4 when processing even fields in multiplier 2B, and then sent to adder 3.
0. The output signal of the 1-line delay circuit 25 is
The multiplier 29 adjusts the gain to 3/8 when processing an odd field and to 5/8 when processing an even field, and supplies the resultant signal to an adder 31.

The output of the adder 31 has its gain halved by a multiplier 32 and is input to a time expansion circuit 34. As shown in FIG. 3, the time expansion circuit 34 expands the time axis of the color difference signal, which has been time-compressed to 1/4 based on the MUSE standard, by four times and outputs it at the same timing as the luminance signal. The output of the time expansion circuit 34 is the color difference signal R-Y from the output terminal 36.
It is output as B-Y. However, in this case, the color difference signal R-
Y and the color difference signal B-Y are output alternately for each line. The output of the addition 'JKH30 is multiplier 33 with a gain of 1.
/2 and output as a luminance signal Y from the output terminal 35.

The above configuration forms a 5-tap filter in the vertical direction, and when processing even fields, the luminance signal is filtered from above (
It has a coefficient of (5/16.0.1/2.0.3/
16). Also, during odd field processing, the luminance signal is processed from above (0, 1/8.1
/2.3/8.0), and a 0-line vertical filter that has a coefficient of (3/16, 0.1/2, 0.5/16) for the color difference signal. A scanning line layout diagram after interpolation processing is shown in FIG.

From the figure, it can be seen that the scanning line arrangement after interpolation processing is the luminance signal and color difference signal, and for the 0 color difference signal, which is aligned in even and odd fields, R-Y and B-Y are output alternately for each line. I know it will happen.

Horizontal interpolation processing is performed by distributing sample point data to non-sample points thinned out by subsampling. That is, as shown in FIG. 5, FIG. 5(a)
The data thinned out to a pixel arrangement like this is transmitted in the same phase as shown in Figure 5(C) based on the MUSE standard, so the data at each adder is transmitted in the same phase as shown in Figure 5(d). After adjusting the timing to shift to the regular pixel position as shown in Figure 5(e), re-sampling is performed at double rate as shown in Figure 5(b), and horizontal interpolation processing is performed as shown in Figure 5(b). will be held.

The video signal subjected to interpolation processing in the intra-field interpolation processing circuit 4 is converted into the number of scanning lines in a time axis conversion circuit 5 in order to convert a high-definition television signal into a standard sequentially scanned television signal. Furthermore, regarding the color difference signal, interpolation processing is performed in the line sequential interpolation processing circuit 6 on the scanning lines of the color difference signal thinned out line sequentially. A luminance signal Y and a color difference signal RY, which are sequentially scanned digital standard television signals output from the time axis conversion circuit 5 and the line sequential interpolation processing circuit 6.

B-Y is converted from a digital signal to an analog signal by a D/A converter 7, and is output as a progressive scanning standard television signal to a Y signal output terminal 8, a R-Y signal output terminal 9, and a B-Y signal output terminal, respectively. It is output from 10.

Further, the luminance signal Y9 color difference RY is a progressive scanning digital standard television signal.

B-Y is thinned out from a progressive scanning standard television signal to an interlaced scanning standard television signal in the scanning line conversion circuit 11, and then converted from a digital signal to an analog signal by the D/A converter 12, and then converted into an interlaced scanning standard television signal. Y signal output terminal 13 as a standard television signal of
, R-Y signal output terminal 14, and B-Y output terminal I5.

As described above, according to the embodiment of the present invention, in an apparatus for converting a conventional MUSE signal into a standard television signal, a luminance signal Y and a color difference signal RY are used.

By simultaneously performing the interpolation processing that was performed individually on B-Y using a single filter configuration, it is possible to reduce the hardware scale of the intra-field interpolation processing section in conventional video signal conversion devices. can.

FIG. 6 shows a block diagram of a video signal converter according to a second embodiment of the present invention. In Figure 6, M
The USE signal is input from the input terminal 41, and the input analog signal is converted into a digital signal by the A/D converter 42. A non-linear de-emphasis filter 43 for restoring the non-linear emphasis characteristic applied when FM transmitting the MUSE signal, converts sub-sampled non-sampled points into samples in the field for the offset-subsampled and transmitted MUSE signal. An intra-field interpolation processing circuit 44 that performs interpolation processing from a point, and a time axis conversion circuit 4 that converts the number of scanning lines of a high-definition television signal to the number of scanning lines of a sequentially scanned standard television signal.
5. D/A converter 46 for converting the converted progressive scan digital standard television signal into an analog signal;
Y of the standard progressive-scanning television signal.

The signals are output as R-Y and B-Y signals from output terminals 47, 48, and 49, respectively. On the other hand, a scanning line conversion circuit 50 thins out scanning lines from a progressive scanning television signal to an interlaced scanning television signal;
After passing through the /A converter 51, the signals are taken out from output terminals 52, 53, and 54 as Y, RY, and BY signals of interlaced standard television signals.

FIG. 7 shows the field interpolation processing circuit 44 in FIG.
FIG. 2 is a block diagram showing the configuration of FIG. In Figure 7, MU
The SE signal is inputted from an input terminal 61, a 1-line delay memory 62, 63, 64, 65, a multiplier 66 whose coefficient changes to 3/8 when processing even fields and 5/8 when processing odd fields, and a multiplier 66 whose coefficient changes to 5/8 when processing odd fields. A multiplier 67 whose coefficient changes to 3/4 when processing an odd field and 5/4 when processing an odd field, a multiplier 68 whose coefficient changes to 1/4 when processing an even field and 3/4 when processing an odd field, and 3 when processing an even field. /
4. Multiplier 69 whose coefficient changes to 1/4 when processing an odd field; multiplier 70 whose coefficient changes to 5/4 when processing an even field; and 3/4 when processing an odd field; 5/8 when processing an even field; Multiplier 71, adder 72, 73.74.1/ whose coefficient changes to 3/8 during odd field processing
In the field, the signal passes through a multiplier 75, 76, 77 having a coefficient of 2, time axis expansion circuits 7B and 79 for color difference signals, and a switching circuit 80 for mutually exchanging the outputs of time expansion circuits 78 and 79 for each line. It is taken out from the output terminal 81 as an interpolated luminance signal. On the other hand, the intra-field interpolated color difference signal RY is taken out from the output terminal 82, and the intra-field interpolated color difference signal B-Y is taken out from the output terminal 83.

The operation of the video signal converter according to the embodiment of the present invention configured as described above will be described below.

First, an analog MUSE signal input to the input terminal 41 is converted into a digital signal by the A/D converter 42. MUSE (No. 3) converted into a digital signal is input to a nonlinear de-emphasis filter 43.

In the nonlinear de-emphasis filter 43,
Processing is performed to restore the nonlinear emphasis characteristic applied when the MUSE signal is FM modulated and transmitted.

Next, the intra-field interpolation processing circuit 44 performs interpolation processing from the sample points within the field of the non-sampled points of the subsampled video signal.

In the intra-field interpolation processing circuit 44, the MUSE signal is supplied to the input terminal 61 as shown in FIG.

The input signal is transmitted through four 1-line delay circuits 62 connected in cascade.
．． 63, 64, and 65 are input sequentially.

The signal branched from the input signal is multiplied by the multiplier 66 to 578 when processing an odd field, and to 3/8 when processing an even field.
The respective gains are adjusted and supplied to the adder 73. 1
The signal branched from the output of the line delay circuit 62 is gain-adjusted by a multiplier 67 to 5/4 when processing an odd field, and to 3/4 when processing an even field, and then sent to an adder 74.
supplied to The signal branched from the output of the one-line delay circuit 62 is further adjusted in gain by a multiplier 68 to 3/4 when processing an odd field, and to 1/4 when processing an even field, and is supplied to an adder 72. A signal branched from the output of the one-line delay circuit 63 is sent to an adder 72 and an adder 7.
3. ■The signal branched from the output of the line delay circuit 64 is processed by the multiplier 69 to 1/1 during odd field processing.
4, the gain is adjusted to 3/4 during even field processing, and the signals are supplied to the adder 72. 1 line delay circuit 6
The signal branched from the output of 4 is further adjusted in gain by a multiplier 70 to 3/4 when processing an odd field, and to 5/4 when processing an even field, and is supplied to an adder 74. The output signal of the 1-line delay circuit 65 is supplied to an adder 73 after its gain is adjusted by a multiplier 71 to 3/8 when processing an odd field and to 5/8 when processing an even field. The output of the adder 72 is sent to a multiplier 75 with a gain of 1/2.
The luminance signal Y is output from the output terminal 81.

The outputs of adders 73 and 74 have their gains halved by multipliers 76 and 77, respectively, and are input to time expansion circuits 78 and 79. In the time expansion circuits 78 and 79, the color difference signal, which has been time-compressed to 1/4 based on the MUSE standard, is
The signal is expanded twice and output at the same timing as the luminance signal. The outputs of the time expansion circuits 78 and 79 are alternately switched line by line by a line switching circuit 80. The operation of the switching circuit 80 will be explained with reference to FIG.

Assuming that the output of the time expansion circuit 78 is time series data as shown in FIG. 8(a), the output of the time expansion circuit 79 will be as shown in FIG. By switching the switching circuit 80 line by line, mutual data is replaced every other line. Therefore, the output terminal 82 outputs the color difference signal RY, and the output terminal 83 outputs the color difference signal B-Y.

The above configuration forms a 5-tap filter in the vertical direction, and when processing even fields, the luminance signal is filtered from above (
It has a coefficient of 0.3/8.1/2.1/8°0), and increases with respect to the color difference signal (5/32. 5/16. I/
4. 3/16. The filter has a coefficient of 3/32). Also, during odd field processing, the luminance signal has coefficients from above (0, 1/8.1/2.3/8.0), and the color difference signal has coefficients from above (3/32. 3/16). ．．
1/4. FIG. 9 shows a scanning line layout diagram after interpolation processing using a zero vertical filter, which is a filter having coefficients of 5/16° and 5/32). It can be seen from the figure that the scanning line arrangement after interpolation processing is uniform for the luminance signal Y, the color difference signals R-Y, B-Y, and even fields and odd fields.

Horizontal interpolation processing is performed by distributing sample point data to non-sample points thinned out by subsampling at each adder, as in the first embodiment.

The video signal subjected to interpolation processing by the intra-field interpolation processing circuit 44 undergoes conversion of the number of scanning lines in a time axis conversion circuit 45 in order to convert a high-definition television signal into a standard television signal of progressive scanning. 0 time axis conversion circuit 45
A luminance signal Y and a color difference signal R-Y, which are progressive scanning digital standard television signals output from
B-Y is converted from a digital signal to an analog signal by a D/A converter 46, and is output as a progressive scanning standard television signal to a Y signal output terminal 47, a R-Y signal output terminal 48, and a B-Y signal output terminal, respectively. 49.

Also, the luminance signal Y1 and the color difference signal RY, which are progressive scanning digital standard television signals.

B-Y is thinned out from a progressive scanning standard television signal to an interlaced scanning standard television signal in a scanning line conversion circuit 50, and then converted from a digital signal to an analog signal by a D/A converter 51, and then converted into an interlaced scanning standard television signal. Y signal output terminal 52 as a standard television signal.
, R-Y signal output terminal 53, and B-Y output terminal 54.

As described above, according to the embodiment of the present invention, the first method is configured to simultaneously perform line-sequential interpolation processing on color difference signals that are thinned out line-sequentially and transmitted according to the MUSE signal standard.
By including the luminance signal Y and the color difference signal R-Y in the intra-field interpolation processing section,
By completing the B-Y interpolation process, it is possible to eliminate the need for the line-sequential interpolation process after time axis conversion in the first configuration.

In the second embodiment, the time axis conversion circuit 45 converts the number of scanning lines from a high-definition television signal to a standard television signal of progressive scanning, but from the beginning it converts the number of scanning lines to a standard television signal of interlaced scanning. If the purpose is to convert the scanning line from a high-definition television signal directly to an interlaced standard television signal in a time axis conversion circuit 55, as shown in FIG. Needless to say, the memory capacity of the axis conversion circuit can be reduced and the scanning line conversion circuit can also be eliminated.

Effects of the Invention As is clear from the above embodiments, according to the present invention, M
In the video conversion output obtained by converting the USE signal to a standard television signal, four interpolation processes are performed on the luminance signal Y and color difference signals R-Y and B-Y of the video signal, whereas conventionally By performing interpolation processing on luminance signals and chrominance signals simultaneously using a filter consisting of a line memory, it is possible to reduce the hardware scale of the interpolation processing section in a video conversion device, and its practical effects are as follows: big.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a video signal conversion device according to a first embodiment of the present invention, FIG. 2 is a block diagram showing an example of the configuration of an intra-field interpolation processing circuit of the same embodiment, and FIG.
The figure is a time series data diagram explaining the operation of the color difference signal time expansion circuit in the intra-field interpolation processing circuit, FIG. 4 is a scanning line layout diagram explaining the operation of the intra-field interpolation processing circuit, and FIG. 5 6 is a pattern diagram showing a pixel arrangement and a time series data diagram for explaining the horizontal interpolation processing operation of the same circuit, and FIG. 6 shows the configuration of a video signal conversion device in a second embodiment of the present invention. Block diagram, FIG. 7 is a block diagram showing an example of the configuration of the intra-field interpolation processing circuit of the same embodiment, and FIG. 8 is a time-series data diagram for explaining the operation of the switching circuit in the intra-field interpolation processing circuit. , No. 9
The figure is a scanning line layout diagram explaining the operation of the intra-field interpolation processing circuit, FIG. 10 is a block diagram showing a configuration example of a video signal conversion device for interlaced scanning standard television signals, and FIG. 11 is a conventional video signal conversion device. FIG. 12 is a block diagram showing the configuration of the signal conversion device. FIG. 12 is a block diagram showing an example of the configuration of the Y vertical filter of the device. FIG. 13 is a scanning line layout diagram for explaining the operation of the Y vertical filter of the device. , (a) in Figure 14,
(b) is R-Y in the conventional video conversion device, respectively.
, a block diagram showing an example of the structure of the BY vertical filter, and FIG. 15 is a scanning line layout diagram for explaining the operation of the vertical filter. 4.44... Field interpolation processing circuit, 5.
45... Time axis conversion circuit, 6... Line sequential interpolation processing circuit, 11.50... Scanning line conversion circuit, 22.23.24°25, 62. 63.64.65
...L line delay circuit, 34°7B, 79.
・・・・・・Time expansion circuit. Name of agent: Patent attorney Akira Okaji and 2 others ---
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Claims (6)

[Claims] (1) Intra-field interpolation means that inputs a high-definition television signal band-compressed by offset subsampling and interpolates non-sampled points from sampled points in the field in order to restore the subsampled signal. , a time axis conversion means for converting the number of scanning lines into a standard television signal of progressive scanning, and a line-sequential means for performing interpolation processing on the line-sequentially thinned out color difference signals to obtain first and second color difference signals. The field interpolation means includes a first horizontal period delay element, and second, third, and fourth delay elements cascaded thereto.
a horizontal period delay element; an interpolation means for interpolating a color difference signal from an input signal, an output signal of the second delay element, and an output signal of the fourth delay element; and an output signal of the first delay element; The apparatus includes interpolation means for interpolating a luminance signal from the output signal of the second delay element and the output signal of the third delay element, and time expansion means for restoring the time-compressed color difference signal. A video signal conversion device. (2) The video signal conversion device according to claim 1, further comprising means for thinning out scanning lines from a progressive scanning television signal to an interlaced scanning television signal at the output stage of the time axis conversion means and the line sequential interpolation means. . (3) Intra-field interpolation means that inputs a high-definition television signal band-compressed by offset subsampling and interpolates non-sampled points from sampled points in the field in order to restore the subsampled signal. , time axis conversion means for converting the number of scanning lines into a standard television signal of progressive scanning, and as the intra-field interpolation means,
a first horizontal period delay element and a second horizontal period delay element cascaded therewith;
, third and fourth horizontal period delay elements, and interpolation processing for interpolating a luminance signal from the output signal of the first delay element, the output signal of the second delay element, and the output signal of the third delay element. means for interpolating the first color difference signal from the input signal, the output signal of the second delay element, and the output signal of the fourth delay element; interpolation means for interpolating the second color difference signal from the output signal of the delay element No. 3; and first and second time expansion means for restoring the time-compressed first and second color difference signals. and switching means for alternating the restored first and second color difference signals line by line to obtain color difference signals R-Y and B-Y, respectively. (4) The video signal converting device according to claim 3, wherein the output stage of the time axis converting means is provided with scanning line converting means for thinning out scanning lines from a progressive scanning television signal to an interlaced scanning television signal. (5) In place of the time axis converting means, a time axis converting means is provided for converting the number of scanning lines of a high-definition television signal to the number of scanning lines of an interlaced standard television signal.
The video signal conversion device described above. (6) The intra-field interpolation processing means interpolates non-sampled points from sample points within the field, and also serves as a pre-filter for time axis conversion processing. video signal converter.