JPH02193480A - Transmission system for wide aspect tv signal - Google Patents

Abstract

PURPOSE:To transmit an image whose aspect ratio is 16:9 as it is by expanding a time base as for a signal of the center part, and enlarging stepwise and successively the compressibility of a part which comes nearer the end part as for signals of both the side parts, so that all the signals are held within a 1H period. CONSTITUTION:A signal C1 of the center part in an output of a screen division processing circuit 2 is inputted to a time base expanding circuit 4, and brought to time expansion to 4/3 fold. A signal L1 of the left end part and a signal R1 of the right end part are inputted to a time base compressing circuit 8, and brought to time base compression to 87.5%, respectively. A signal L2 of the left end part and a signal R2 of the right end part are inputted to a time base compressing circuit 9, and brought to time base compression to 40%, respectively. On the other hand, a signal of a horizontal flyback period S0 becomes a signal S01 to which deformation is performed by a waveform deforming circuit 3. Each signal S01, C11, L11, R11, L21 and R21 which is subjected to these deformation, expansion and compression is inputted to a multiplexer 6, rearranged in order of S01, R21, L21, L11, C11 and R11, and inserted into 1H.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] This invention provides wide aspect ratio images to
This invention relates to a wide-aspect TV signal transmission system that can transmit data over a period of 63.5 μs and maintain compatibility with current receivers.

[Conventional technology]

FIG. 3 shows, for example, ]TEJ Technical
Report Vol, 12 No, 30pp4
3-48. TEBS 88-22 (Aug, 198
8) is a processing circuit diagram of a signal processing system of the conventional wide aspect TV signal transmission method shown in ``Wide screen by multiplexing signals within horizontal blanking period''.

In the figure, (1) is an input terminal, and the video period (52,
6 μs), a video signal A (shown in FIG. 4(a)) carrying an image signal with an aspect ratio of 16:9 is input manually. This video signal A is given to the screen division processing circuit (2), where it is divided on the time axis as shown in FIG. 4) and the time axis compression circuit (5), respectively. Output S of the synchronization signal modification circuit (3). l. Time axis expansion circuit (4)
output C81, and output L of the time axis compression circuit (5)
O1+Ro+ is applied to a multiplexer (6), and from the multiplexer (6), a video signal E is obtained by compressing the input image signal A with an aspect ratio of 16:9 to an aspect ratio of 14.8:9.

(shown in FIG. 4(dl, (e)) is output to the output terminal (7).

Next, the operation of this conventional example will be explained with reference to FIG.

FIG. 4(a) is a diagram showing the signal waveform of one horizontal scanning period (hereinafter referred to as rlHJ) (63.5 gs) of the human video signal A, where the horizontal blanking period is 1089 μs and the video period is 52.6 μs. It is. A horizontal synchronizing signal and a burst signal are carried in this horizontal retrace period, and R6 is carried in the video period.
:9 image signals are listed. This video signal A is divided on the time axis by the screen division processing circuit (2) into a horizontal retrace period S0, a left edge Lo, a center C0, and a right edge R0 as shown in FIG. 4(b). be done. The division ratio of the image period is [4°:Co:Ro=2:12:2, and if expressed in time, L::6.575μS, CO:39.4
5 μs, Ro: 6.575 μs.

Output S of the screen division processing circuit (2). , L O+ C
o, R8, the central part C8 is a time axis expansion circuit (4
) to fit within a period of 52.6 μs.
Signal C81 whose time axis has been expanded by 4/3 (Fig. 4(c)
), and the left end L0 and right end R6 are input to the 1-time axis compression circuit (5), and the time axis is compressed by 0.5 times, respectively.The signal L01. R01 (shown in FIG. 4(c)), and the signal S0 during the horizontal retrace period is input to the synchronizing signal modification circuit (3), and as shown in FIG. 4(e), the width of the horizontal synchronizing signal and The width of the front porch is compressed and the signal S has a period of 6.3 μs. , and are respectively input to the multiplexer (6). The multiplexer (6) converts each input signal into S as shown in FIG. 4(d).
. lRo++ Sort in the order of Log, Cot and l
)! (63,5μs) period, but L o+
And the total time of R61 is 6.575 μs, and the fourth
As shown in figure (c), it does not fit within the IH period of 63.5 μs. Therefore, the LOI and RoI signals were reduced by about 30% and about 70% of the signals were placed on the multiplexed signal area and arranged as shown in FIG. 4(d) and (e), with an aspect ratio of 14.8: 9 output video signal E.

I am getting .

This is a waveform diagram for explaining the mode of modification of the horizontal synchronization signal, etc. in the fifth opening/opening period signal modification circuit (3). A multiplexed signal area of about 4.6 μs is secured by narrowing the period from the end of the burst signal to the start of the video period.

Video signal E multiplexed in this way. is the general N T
On SC receivers, the center CI portion is displayed as the playback screen, and on widescreen receivers, the center portion C81 is displayed as the playback screen.
is reduced to 3/4, and the video signals R6I+LOI on both sides multiplexed during the horizontal retrace period are extracted, enlarged twice, and added to both sides of the center area to be displayed as a 14.8:9 image. It will be done.

[Problem to be solved by the invention]

In this way, in the conventional wide-aspect TV signal transmission system, the left edge of the image signal. , about 70 of the right end R0
Since only % can be transmitted, the aspect ratio of the reproduced image is 1.
The ratio was about 4.8:9. In addition, since the center C6 is not compressed and the left and right edges are compressed by 50%, the high frequency components are lost due to band limitation, causing a sudden change in image quality at the boundary of the reproduced image. There was a problem.

This invention was made to solve the above-mentioned problems, and it is possible to transmit an image with an aspect ratio of 16:9 as it is, and it is also possible to transmit a wide aspect TV signal with a gradual change in image quality on the playback screen. The purpose is to obtain a transmission method.

[Means for solving the problem] The wide aspect TV signal transmission system according to the present invention includes:
The input video signal is divided into multiple parts, including the horizontal blanking period, the center of the image period, and both sides thereof, and the horizontal synchronization signal and other synchronization signals are modified to the extent that compatibility with the NTSC system can be ensured. is applied to create a multiplexed signal region, and the time axis of the central signal is expanded, and the compression ratio of the signals on both sides increases step by step toward the ends, so that all the signals are in the lH period. The main feature is that the central signal is placed in the middle of the video period, and the signals on both sides are arranged and transmitted so that they are placed in the frequently used area and the remaining part of the video period.

[Effect]

According to this invention, the synchronization signal and all signals within the video period can be inserted and transmitted within the IH period, so the reproduced image of the wide screen receiver can be obtained with the same aspect ratio as the original input signal. . Furthermore, since the compression ratio is changed in stages for each part of the image signal, changes in the image quality on the screen that occur at the boundaries are alleviated.

[Embodiments of the invention]

An embodiment of this invention will be described below.

FIG. 1 is a block circuit diagram of an embodiment of the present invention. In the figure, the same reference numerals as in FIG. 3 indicate the same or corresponding parts, and (8) is the first time-base compression circuit;
) is the second time-base compression circuit.

Next, the operation will be explained.

Figure 2 (al is IH (63,5μ) of input video signal A
The signal waveform of S) is shown.

This video signal A is given to the screen division processing circuit (2), and as shown in FIG. 2(b), there is a horizontal retrace period S0 of 1009 μs and a left end L3 . It is divided into a left end portion L1, a center portion C1, a right end portion R1, and a right end portion R2. For example, the division ratio is 5.756 seconds for each of the left end L3 and right end R3, and 36.7 seconds for the center C1.
．． 3gs, left end L1 and right end R, 2.4μs each
It is.

The central signal C1 among the outputs of the screen division processing circuit (2)
is input to the time axis expansion circuit (4) and is time expanded by 4/3 as shown in FIG. 2 (cl).The signal !41 at the left end and the signal r< The signals are input to the time axis compression circuit (8) and are compressed to 87.5% as shown in FIG. 2(c).The signal L at the left end
2 and the right end signal 1 (2) are input to the time axis compression circuit (9) and are compressed to 40% in time axis, respectively, as shown in FIG. is the signal S that has been modified in the same manner as in the conventional example by the waveform modification circuit (3).
It becomes OL. Each signal S that has undergone these transformations, expansions, and compressions. ++ C++, L+++ n11. La1n
Rat is input to the multiplexer (6), and as shown in Fig. 2 (
d) as shown in S. 1. Rx1. L□In L
++, C)++ R++, and I
It is inserted into H.

FIG. 2(e) shows the IH waveforms of the video signal El, each of which is 2.3 gs, C, 48.4 us, and Lll and Ro each 2.1 μs.

Therefore, [1, C0 and &RII are within 52.6 μs of the video period, and R11% La1 is 4.6
All can be placed within the μs multiplex signal range. Therefore, the reproduced image obtained by reproducing this video signal E on a wide receiver can be reproduced with the aspect ratio (16:9) of the human image as it is.

Note that when this video signal is received by a current receiver, there are signals of Ro and Ro within the video period, but since these portions correspond to the overscan portion, no particular problem occurs.

Note that the number of divisions of the video period, the division ratio, the compression rate and expansion rate of each part shown in the above example are just examples, and the current NT
A multiplexed signal area is secured while maintaining compatibility with standard systems such as the SC system, and the number of divisions and divisions are such that all wide aspect ratio images can be mounted within that area and within the current video period. [Effects] As shown in E-E, according to the present invention, the entire image signal of a wide aspect ratio image is divided into a plurality of parts at the center and both sides thereof, and the compression ratio is sequentially increased toward both sides. Since all image signals are transmitted in a multiplexed signal area provided by compressing the video period and the horizontal retrace period, it is possible to transmit a video signal with an aspect ratio of 16:9. Furthermore, since the compression ratio of the image signal is changed in stages, it is possible to alleviate changes in image quality that occur at the boundaries of the reproduced image.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram of an embodiment of the present invention, and FIG.
The figure shows the signal processing and signal waveforms of each part of this embodiment, Figure 3 is a block circuit diagram of a configuration example of a conventional wide aspect TV signal transmission system, and Figure 4 shows the signal processing and signal waveforms of each part. FIG. 5 is a waveform diagram for explaining a modified example of the synchronizing signal in the conventional synchronizing signal modifying circuit. (2) --- Screen division processing circuit, (3) --- Synchronization signal modification circuit, (4) --- Time axis expansion circuit, (51
, (8) , (91-... time axis compression circuit, (6)
...Multiplexer. In each figure, the same reference numerals indicate the same or equivalent parts.

Claims (1)

[Claims] (1) Divide a wide aspect ratio video signal into a horizontal blanking period and a video period, and further divide this video period into at least two parts each at the center and on both sides, and Horizontal synchronization signals and burst signals are modified to narrow the required period within a range that maintains compatibility with standard systems such as NTSC, and a multiplexed region is created. The time axis is expanded in the first part, and the time axis is compressed on both sides with a compression rate that gradually increases toward the ends.The central part with the time axis expanded is the central part of the video period of the original signal. Both sides subjected to time axis compression are rearranged so that the lower the compression ratio is, the closer the position is to the center, and the transformed synchronization signal and the rearranged video signal are transmitted for one horizontal scanning period of the original signal. When the video signal is received by a wide screen receiver, the video signal is rearranged according to the divided sections and returned to its original position, and the time axis is compressed and expanded to restore the original aspect. A wide-aspect TV signal transmission system configured to display a video signal within a video period when received by a standard receiver such as the NTSC system.