JPH06268977A - Transmission method and reproducing method for television signal - Google Patents

Abstract

PURPOSE:To reduce the range of erroneous reproduction due to noises by inserting reference signals for reset in auxiliary signals for respective N picture elements, taking differences between adjacent picture elements in a horizontal direction, then substituting the differential reference signals with the original reference signals and multiplexing them on upper and lower nonpicture parts. CONSTITUTION:When write pulses Wp supplied from an N-ary counter 206 are supplied, an insertion circuit 202 inserts the reference signals Re for reset in the auxiliary signals for respective N picture elements. A one-clock delay circuit 203 delays the auxiliary signals to which the reference signals Re are inserted for the respective N picture elements supplied from the insertion circuit 202 for one clock and supplies them to a subtracting circuit 204. The subtracting circuit 204 obtains difference signals by subtracting the one-clock delayed auxiliary signals from the auxiliary signals and supplies them to a substituting circuit 205. The substituting circuit 205 substitutes the differential reference signals Res again with the reference signals Re. Such difference signals are multiplexed on the upper and lower non-picture parts and transmitted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a television signal transmission method, and particularly has compatibility with the current NTSC broadcasting,
The present invention relates to a so-called letterbox type high-definition wide-aspect television signal transmission method in which an aspect ratio of a screen center portion is 4: 3 or more and multiple signals are superimposed on upper and lower non-picture area regions of a screen.

[0002]

2. Description of the Related Art An auxiliary signal is added to a television signal while maintaining compatibility with a current NTSC image signal having an aspect ratio of 4: 3 so that a wide image having a high image quality aspect ratio of 16: 9 is displayed. Several transmission methods have been conventionally proposed. An example of one of the letterbox methods will be described with reference to FIGS. 14 to 22.

The original image shown in the left part of FIG. 22 is a scanning line 525.
This is an original image with a wide aspect ratio of 16: 9. In order to display this video signal on a current receiver having an aspect ratio of 4: 3, 480 effective scanning lines are vertically compressed to 3/4 times as shown in the right part of FIG. 22 to obtain 360 main images. (B portion), the upper and lower 60 lines are the A portion and the C portion are black or gray images of the non-image portion. The auxiliary signal is multiplexed in this non-picture part. Here, the vertical high frequency band lost when the effective scanning lines of the original image are compressed from 480 to 360 lines in the vertical direction by 3/4 times as the auxiliary signal. Use signals. This auxiliary signal is multiplexed and transmitted to the upper and lower non-picture portions shown in A and C of FIG. When this is displayed on a current NTSC color television signal receiver (hereinafter simply referred to as a current receiver), FIG.
As shown in the right part of 2, the upper and lower parts are non-image parts, and an image with an aspect ratio of 16: 9 can be obtained in the center.

On the other hand, when this signal is received by the wide aspect receiver, the 360 lines in the central portion are vertically moved to 4 /
A wide aspect image of 480 original effective scanning lines can be obtained by expanding the signal three times, extracting and reproducing the auxiliary signals multiplexed in the upper and lower non-picture portions, and performing vertical compensation.

FIG. 14 shows a conventional example on the transmitting side. In the figure, a video signal is input from a video signal input terminal 101, and a vertical low-pass filter (hereinafter abbreviated as VLPF) 1
02 and a vertical high-pass filter (hereinafter abbreviated as VHPF) 103, and synchronizing signals H and V (H represents a horizontal synchronizing signal and V represents a vertical synchronizing signal) from a synchronizing signal input terminal 115 are input to a clock input terminal. The clock 4fsc (14.31) which is four times the color subcarrier fsc
818 MHz) is supplied to each element and each circuit. The VLPF 102 extracts only the vertical low-pass component of the video signal input by the vertical low-pass filter.
It is supplied to the / 4 compression circuit 104. 3/4 compression circuit 104
Supplies the low-frequency signal to the switch 106 as a main image signal compressed from 480 effective scanning lines to 360 by thinning out the scanning lines from 4 to 3. On the other hand, VHPF1
03 extracts only the vertical high-frequency components of the video signal input by the vertical high-pass filter, and the 1/4 compression circuit 105
Supply to. The 1/4 compression circuit 105 supplies the vertical high-frequency signal scanning line supplied from the VHPF 103 to the differential circuit 500 as an auxiliary signal that is compressed from 4 to 1 thinning effective scanning lines from 480 to 120.

The difference circuit 500 has a structure as shown in FIG. 16, and the auxiliary signal supplied from the 1/4 compression circuit 105 of FIG. 14 is supplied to the 1-clock delay circuit 502 and the subtraction circuit via the auxiliary signal input terminal 501. 503 is supplied. The one-clock delay circuit 502 uses the supplied auxiliary signal for one clock {1 / (14.18181 MHz) = 69.84 * 1.
0 ^-9 seconds} delay and supply to the subtraction circuit 503. The subtraction circuit 503 subtracts the auxiliary signal delayed by one clock from the auxiliary signal to obtain a differential signal and supplies it to the switch 106 of FIG. 14 via the differential signal output terminal 504. That is, when the auxiliary signal A as shown in FIG. 18 is input, the difference signal has a waveform as shown in FIG. 19B which is the difference between pixels in the horizontal direction, and the amplitude level becomes small, so that it is displayed on the current receiver. In this case, the obstruction of the upper and lower non-image areas becomes less noticeable.

The switch 106 in FIG. 14 is switched to the side a when the video signal is the main image of the center portion, and supplies the main image signal supplied from the 3/4 compression circuit 104 to the letterbox signal output terminal 107, and also the video. When the signal is in the upper and lower non-image area, it is switched to the side b and the differential signal supplied from the differential circuit 500 is supplied to the letterbox signal output terminal 107. Although the switching timing of the switch 106 is not shown here, for example, by counting the synchronizing signals H and V supplied from the synchronizing signal input terminal 115, the timing can be determined by detecting the center portion and the upper and lower non-image portions of the image. It can be measured.

The letterbox signal output terminal 107
When the output letterbox signal is displayed on the current receiver, it is possible to obtain a letterbox image in which the upper and lower parts are non-image areas as shown in the right part of FIG.

Next, a conventional example on the receiving side will be described with reference to FIG.

The letterbox signal input from the letterbox signal input terminal 108 is supplied to the switch 109. The switch 109 switches to the c side when the video signal is the main image of the center portion, and the main image signal is expanded to the 4/3 expansion circuit. 1
10 and supplies the video signal to the d side when the video signal is in the upper and lower non-picture areas, and reproduces the differential signal multiplexed in the upper and lower non-picture areas.
Supply to 0. The 4/3 expansion circuit 110 is a switch 109.
The main image signal of 360 scanning lines supplied from the above is expanded to 4/3 times and supplied to the VLPF 102 as 480 scanning lines. The VLPF 102 removes unnecessary vertical high-frequency components, extracts only necessary vertical low-frequency components, and supplies them to the adder circuit 112.

On the other hand, the reproducing circuit 600 has the structure shown in FIG. 17, and the differential signal supplied from the switch 109 in FIG. 15 is added to the adding circuit 60 via the differential signal input terminal 601.
3 is added to the differential signal input terminal 60
1 differential clock signal and 1 clock delay circuit 602
Then, the differential signal is reproduced by adding the delayed signal delayed by 1 clock and is supplied to the 1-clock delay circuit 602. The reproduced auxiliary signal is a 1-clock delay circuit 60.
2 through the auxiliary signal output terminal 604 to the quadruple expansion circuit 111 of FIG.

The 4 × expansion circuit 111 of FIG. 15 expands the supplied auxiliary signals of 120 scanning lines by 4 times and the scanning line 480.
It is supplied to the VHPF 103 as a book. The VHPF 103 removes unnecessary vertical low-frequency components, extracts only necessary vertical high-frequency components, and supplies them to the adder circuit 112. Adder circuit 11
2 is the main image signal and VHP supplied from the VLPF 102.
The auxiliary signals supplied from F103 are added and supplied to the video signal output terminal 113.

When the video signal output from the video signal output terminal 113 is displayed on a wide aspect receiver, a high-definition image with an aspect ratio of 16: 9 of 480 scanning lines can be obtained.

[0014]

However, in the prior art, for example, when noise or the like is mixed in the difference signal between the upper and lower non-picture portions during transmission as shown by the mark X of the signal C in FIG. When the reproduced difference signal is reproduced, there is a problem that the auxiliary signal is not reproduced correctly because it affects the subsequent pixels as indicated by the triangle mark of the signal D in FIG.

It is an object of the present invention to provide a television signal transmission method and a reproduction method that can be correctly reproduced on the reproduction side even if noise or the like is mixed in the differential signal during transmission.

[0016]

In order to solve the above problems, the present invention <A> is compatible with the current standard television broadcasting method,
In a wide aspect television signal transmission method in which an auxiliary signal for high image quality is multiplexed and transmitted to a portion which becomes an upper and lower non-image part of a screen of the current standard television broadcasting method,
A reference signal R for each N (N is a natural number) pixels in the auxiliary signal.
a means for making a difference between adjacent pixels in the horizontal direction after inserting e, and a difference signal containing the reference signal Re for every N pixels by replacing the difference reference signal Res with the reference signal Re, and The difference signal is multiplexed and transmitted to the upper and lower non-image parts.

<B> An auxiliary signal which is compatible with the current standard television broadcasting method, and which is composed of a differential signal between adjacent pixels in the horizontal direction is provided in the upper and lower non-picture portions of the screen of the current standard television broadcasting method. A transmission method for multiplexing and transmitting a wide aspect television signal, comprising means for extracting a reference signal Re from the difference signal on the receiver side, and extracting the reference signal Re from the difference signal, and then extracting the reference signal Re The difference signal is converted into N by using the signal Re.
The auxiliary signal is reproduced while resetting each pixel, and is added to the main image portion to reproduce a high-quality wide aspect video signal.

<C> It is compatible with the current standard television broadcasting method, and the difference signal between adjacent pixels in the horizontal direction and every N pixels are provided in the upper and lower non-picture portions of the screen of the current standard television broadcasting method. A method of receiving a wide aspect television signal in which an auxiliary signal including a reference signal Re is multiplexed, comprising: means for extracting the reference signal Re from the difference signal, at the timing when the reference signal Re is inserted. Reference signal R equivalent to the reference signal Re inserted at the transmitting side
a reference signal Rd generated on the receiver side after the reference signal Re is extracted from the difference signal, and the auxiliary signal is reproduced while resetting every N pixels. Along with this, a wide aspect video signal of high image quality is reproduced by adding it to the main image portion.

[0019]

In the present invention, the reference signal Re is inserted into the auxiliary signal every N pixels on the transmitting side, and the difference between the adjacent pixels in the horizontal direction is calculated. Then, the difference reference signal Res is used as the reference signal Re. The replaced difference signal is created and multiplexed and transmitted to the upper and lower non-image parts, and the receiving side multiplexes the reference signal Re from the difference signal and extracts the reference signal Re from the difference signal for each N pixel. Since the auxiliary signal is reproduced while resetting, the range of erroneous reproduction due to noise can be reduced.

Further, at the receiver side, the same reference signal Rd as the reference signal Re multiplexed at the transmission side is generated to reproduce the auxiliary signal while resetting every N pixels and thus the reference signal Re.
Even if the device itself changes due to noise during transmission, it is possible to prevent erroneous reproduction.

[0021]

Embodiments of the present invention will be described below with reference to FIGS. 1 to 7. The same parts as those of the conventional example are designated by the same reference numerals and the description thereof will be omitted.

FIG. 1 is an overall block diagram of the transmitting side of the present invention. In the figure, the auxiliary signal processing circuit 200 has a configuration as shown in FIG. 3, and the 1/4 compression circuit 105 of FIG.
The auxiliary signal supplied from the auxiliary signal input terminal 20 of FIG.
1 to the insertion circuit 202. The N-ary counter 206 generates a write pulse Wp every five clocks, for example, and supplies it to the insertion circuit 202 and the timing control circuit 208. The reference signal Re generation circuit 207 is a reference signal Re when the difference signal is reproduced on the receiving side.
(Here, the size of Re is 3) is generated and supplied to the insertion circuit 202 and the replacement circuit 205. Insertion circuit 2
Reference numeral 02 inserts the reference signal Re into the auxiliary signal when the write pulse Wp supplied from the N-ary counter 206 is supplied. For example, when the auxiliary signal as shown in FIG. 6 is input, the reference signal Re is inserted into the auxiliary signal every 5 pixels as shown in FIG.
Supply to. (The horizontal axis in FIGS. 6 to 9 represents time coordinates, and the vertical axis represents amplitude level.) 1 Clock delay circuit 2
03 indicates that the reference signal Re supplied from the insertion circuit 202 is 5
The auxiliary signal inserted for each pixel is 1 clock {1 /
(14.18181 MHz) = 69.84 * 10 ⁻⁹ seconds}
It is delayed and supplied to the subtraction circuit 204. Subtraction circuit 204
Is obtained by subtracting the auxiliary signal delayed by one clock from the auxiliary signal to obtain a differential signal as shown in FIG.
Supply to 05. The replacement circuit 205 replaces the reference signal Res that has been differentiated as shown in FIG. 9 with the reference signal Re again.
That is, the timing control circuit 208 writes the write pulse Wp ′ from the N-ary counter so that the write pulse Wp is aligned with the reference signal Res which is the difference.
Is generated and supplied to the replacement circuit 205. Replacement circuit 205
Is a reference signal R supplied from the reference signal Re when the write pulse Wp ′ is supplied.
Replace with e. FIG. 9 shows the waveform of the differential signal in which the differential reference signal Res is replaced with the reference signal Re. The difference signal is output via the difference signal output terminal 209.
When such a differential signal is multiplexed on the upper and lower non-image parts, only the reference pulse becomes conspicuous when the image is displayed on the current receiver, and the differential signal becomes less conspicuous. Further, the difference value immediately after the reference signal becomes large, but it is difficult to stand out because of the reference signal.

Next, the receiving side of the present invention will be described with reference to FIGS.

In FIG. 2, the auxiliary signal reproducing circuit 300 has a structure as shown in FIG. 4, and the differential signal multiplexed in the upper and lower non-image parts is supplied from the switch 109 in FIG. 2 and the differential signal input in FIG. It is supplied to the extraction circuit 302 via the terminal 301. The N-ary counter 305 generates the sampling pulse Gp and the switching pulse Sp every 5 clocks in the same cycle as the transmitting side, and the sampling pulse Gp is supplied to the sampling circuit 302 and the switching pulse Sp is supplied to the switch 306, respectively. When the sampling pulse Gp is supplied from the N-ary counter 305, the sampling circuit 302 samples the reference signal Re in the differential signal as shown in FIG. 11 when the differential signal shown in FIG. The taken reference signal Re is supplied to the timing control circuit 307, and the difference signal (FIG. 11) obtained by extracting the reference signal Re is supplied to the addition circuit 304. The adder circuit 304 reproduces the auxiliary signal by adding the difference signal supplied from the sampling circuit 302 and the signal supplied from the switch 306 and supplies the auxiliary signal to the 1-clock delay circuit 303. The 1-clock delay circuit 303 delays the signal (B) supplied from the adding circuit 304 by 1 clock and supplies it to the switch 306, and at the same time, outputs it via the auxiliary signal output terminal 308. On the other hand, the timing control circuit 307 switches the reference signal Re supplied from the sampling circuit 302 to the reference signal Re supplied from the sampling circuit 302 at the timing when the reproduction process is reset, that is, the timing when the reference signal Re is inserted.
Supply to 6. The switch 306 is normally closed to the a side, and when the switching pulse Sp is supplied from the N-ary counter, it is closed to the b side and supplies the reference signal Re supplied from the sampling circuit 302 to the addition circuit 304. That is, the auxiliary signal shown in FIG. 12 can be reproduced by reproducing the differential signal while resetting the reference signal Re every 5 pixels. A timing chart of the above operation is shown in FIG. At this time, the initial value y ₀ of the difference signal is always at 0 level. See also FIG.
The alphabet in 3 corresponds to the alphabet in FIGS. 4 and 10 to 12.

Next, another embodiment of the receiving side of the present invention will be described with reference to FIGS.

The differential signal multiplexed in the upper and lower non-image parts is supplied from the switch 109 in FIG. 2 and is supplied to the auxiliary signal reproducing circuit 3 in FIG.
The sampling circuit 40 through the differential signal input terminal 401 of 00 '
2 is supplied. The N-ary counter 405 generates a sampling pulse Gp and a switching pulse Sp every 5 clocks in the same cycle as the transmitting side, and in the present embodiment, the sampling pulse Gp is supplied to the sampling circuit 4.
02, and the switching pulse Sp is supplied to the switch 406.
Is supplied to. When the sampling circuit 402 is supplied with the sampling pulse Gp from the N-ary counter 405, the differential signal input terminal 4
The reference signal Re in the difference signal supplied from 01 is extracted and supplied to the adding circuit 404 as a waveform as shown in FIG. The reference signal generating circuit 407 generates the same reference signal Rd as the reference signal Re inserted in the auxiliary signal on the transmitting side and supplies it to the switch 406. The adder circuit 404 adds the difference signal supplied from the sampling circuit 402 and the signal supplied from the switch 406 to reproduce the auxiliary signal and supplies it to the 1-clock delay circuit 403. The 1-clock delay circuit 403 delays the signal supplied from the adder circuit 404 by 1 clock and supplies it to the switch 406 and the auxiliary signal output terminal 408. The switch 406 is normally closed to the a side, and when the switching pulse Sp is supplied from the N-ary counter, it is closed to the b side and supplies the reference signal Rd supplied from the reference signal Rd generation circuit 407 to the addition circuit 404. That is, the auxiliary signal can be reproduced while resetting with the reference signal Rd every 5 pixels.

In the present embodiment, the reference signal Re is inserted every 5 pixels, but this is for the sake of easy description, and the present invention is not limited to this.

[0028]

According to the present invention, the reference signal Re for resetting is inserted into the auxiliary signal for every N pixels to make a difference between adjacent pixels in the horizontal direction, and then the reference signal which is the difference is used as the original reference signal. Since it is replaced with Re and is multiplexed in the upper and lower non-image portions, the difference signal in the upper and lower non-image portions has a smaller multiplexing level and becomes less conspicuous when displayed on the current receiver. Further, although the pixel level before and after the reference signal may increase, the reference signal is always at a constant level, so that only the reference signal Re is conspicuous, and the level difference is visually absorbed, making it less conspicuous.

Since the auxiliary signal is reproduced while being reset by the reference signal, erroneous reproduction is reduced.

Further, even when the transmitted reference signal Re itself is erroneous during transmission, the reference signal Rd generated on the receiving side is reset, so that the auxiliary signal can be reproduced.

[Brief description of drawings]

FIG. 1 is an overall block diagram of a transmitting side of the present invention.

FIG. 2 is an overall block diagram of a receiving side of the present invention.

FIG. 3 is a block diagram of an auxiliary signal processing circuit of the present invention.

FIG. 4 is a block diagram of an auxiliary signal reproducing circuit of the present invention.

FIG. 5 is a block diagram of another embodiment of the auxiliary signal reproducing circuit of the present invention.

FIG. 6 shows an auxiliary signal according to the present invention.

FIG. 7 shows an auxiliary signal with a reference signal inserted according to the present invention.

FIG. 8 is a diagram showing a differential signal according to the present invention.

FIG. 9 shows a reference signal in which the subtracted reference signal is replaced according to the present invention.

FIG. 10 is a diagram showing a differential signal according to the present invention.

FIG. 11 is a diagram showing a differential signal from which a reference signal is extracted according to the present invention.

FIG. 12 is a diagram showing an auxiliary signal reproduced from a differential signal according to the present invention.

FIG. 13 is a timing chart according to the present invention.

FIG. 14 is an overall block diagram of a conventional transmitting side.

FIG. 15 is an overall block diagram of a conventional receiving side.

FIG. 16 is a block diagram of a conventional difference circuit.

FIG. 17 is a block diagram of a conventional reproducing circuit.

FIG. 18 is a diagram showing an auxiliary signal according to a conventional example.

FIG. 19 is a diagram showing a differential signal according to a conventional example.

FIG. 20 is a diagram showing a differential signal in which noise is mixed according to a conventional example.

FIG. 21 is a diagram showing a reproduced differential signal according to a conventional example.

FIG. 22 is a diagram showing a general letterbox wide aspect image transmission method.

[Explanation of symbols]

 101 video signal input terminal 102 low-pass filter for video signal 103 high-pass filter for video signal 104 3/4 compression circuit 105 1/4 compression circuit 106, 109 switch 110 4/3 expansion circuit 111 4 times expansion 112 addition circuit 200 auxiliary signal processing Circuit 201 Auxiliary signal input terminal 202 Insertion circuit 203 1 Clock delay circuit 204 Subtraction circuit 205 Substitution circuit 206 N-ary counter 207 Reference signal Re generation circuit 208 Timing control circuit 209 Differential signal output terminal 300 Auxiliary signal reproduction circuit 301 Differential signal input terminal 302 Extraction circuit 303 1-clock delay circuit 304 Addition circuit 305 N-ary counter 306 Switch 307 Timing control circuit 308 Auxiliary signal output terminal 401 Differential signal input terminal 402 Extraction circuit 03 1 clock delay circuit 404 adder circuit 405 N-ary counter 406 switches 407 reference signal Rd generating circuit 408 auxiliary signal output terminal

Claims (3)

[Claims] 1. A wide system which is compatible with the current standard television broadcasting method and which multiplexes and transmits an auxiliary signal for high image quality in the upper and lower non-picture portions of the screen of the current standard television broadcasting method. In the aspect television signal transmission method, means for inserting a reference signal Re for each N (N is a natural number) pixel in the auxiliary signal and then making a difference between adjacent pixels in the horizontal direction, and the difference reference signal Res By the means for replacing with the reference signal Re, the reference signal R for every N pixels
A wide aspect television signal transmission method, wherein a differential signal containing e is multiplexed and transmitted to the upper and lower non-picture portions. 2. A differential signal between adjacent pixels in the horizontal direction and N, which is compatible with the current standard television broadcasting method, and which is a vertical non-image portion of the screen of the current standard television broadcasting method.
A method for reproducing a wide aspect television signal in which an auxiliary signal including a reference signal Re is multiplexed for each pixel, wherein the reference signal Re is extracted from the difference signal by means for extracting the reference signal Re from the difference signal. After that, the difference signal is converted to N by using the extracted reference signal Re.
A wide aspect television signal reproducing method characterized in that an auxiliary signal is reproduced while resetting each pixel and a high quality wide aspect video signal is reproduced by adding the auxiliary signal to a main image portion. 3. A differential signal between adjacent pixels in the horizontal direction and N, which is compatible with the current standard television broadcasting method, and which is an upper and lower non-image portion of the screen of the current standard television broadcasting method.
A method for reproducing a wide aspect television signal in which an auxiliary signal including a reference signal Re is multiplexed for each pixel, and means for extracting the reference signal Re from the difference signal,
It is generated at the receiver side after extracting the reference signal Re from the difference signal by means of generating a reference signal Rd equivalent to the reference signal Re inserted at the transmission side at the timing when the reference signal Re was inserted. Wide aspect television signal characterized in that the auxiliary signal is reproduced while resetting every N pixels using the reference signal Rd and a high quality wide aspect video signal is reproduced by adding the auxiliary signal to the main image portion. How to play.