JPS6379488A - Television signal forming method - Google Patents

Abstract

PURPOSE:To obtain a laterally long picture compatible with a current system by dividing a picture larger 4:3 in an aspect ratio into a main picture and a sub-picture by time base multiplexing and frequency axis multiplexing the low frequency component and the high frequency component of the sub-picture on the main picture, respectively. CONSTITUTION:The picture larger than 4:3 in the aspect ratio inputted to an input terminal 1 is separated to a main picture signal consisting of the picture of an area M of the aspect ratio of 4:3 and a sub-picture signal indicated by a slashed area in a picture separating circuit 2. The main picture signal M is fed to an NTSC system encoder, directly encoded to an NTSC signal and supplied to a time base multiplex circuit 8. The sub-picture signal is supplied to an LPF4 and a subtracter 5, the low frequency component from the LPF4 is time base compressed and time base multiplexed in the time base multiplex circuit 8. The high frequency component from the subtracter 5 is time base extended and thereafter, frequency axis multiplexed in a frequency axis multiplex circuit 9.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is a method for forming a television signal that is compatible with current television receivers and that enables television broadcasting with an expanded aspect ratio in the horizontal direction. It is related to.

Conventional technologyCurrent NTSC (National Televisi)
Approximately 25 years have passed since color television broadcasting using the on-system computer system began in 1961. Meanwhile, various new television systems have been proposed in response to demands for high-definition screens and improved performance of television reception layers. Furthermore, the content of the programs being serviced has changed from typical studio programs and broadcast programs to programs with higher quality and more realistic images, such as cinema-sized movie broadcasts.

Against this background, the Japan Broadcasting Corporation (NIIK) proposed a high-definition television system [for example, the literature special feature on high-definition television (Television Society Journal Vol. 36,
No. 10, 1982)].

The contents include high definition with a scanning line count of 1125, interlaced scanning, and a brightness horizontal bandwidth of 20MH7, as well as a screen aspect ratio of 5:3 from the viewpoint of visual engineering such as a sense of realism.
That is. This system has already been almost completed in the closed system, and with the start of satellite broadcasting, M
We have proposed a USE system [Reference, Tasuku Ninomiya et al., Satellite 1-channel transmission system (MUSE) for high-definition television (Electronic Communication All Technology Research Report IE84-72, 1982)] and are conducting experiments.

On the other hand, the current NTSC system has specifications such as 525 scanning lines, interlaced scanning, a luminance horizontal bandwidth of 4.2 MHz, and an aspect ratio of 4:3.

As an image quality improvement method for the current NTSC system, a method of frequency multiplexing high-frequency information of an image (Public Patent Publication No. 12883/1986) has already been proposed as a method to improve horizontal resolution.
High-definition signal converters for television signals (see ``High Definition Signal Converter'') have been proposed. Further, as a method for improving the resolution in the vertical direction, a method of performing ink-lace scanning-no-inclace scanning conversion has been proposed. In this way, the current NT
Although several practical methods have been proposed for increasing the definition of the SC method, no practical methods have been proposed regarding the aspect ratio, which greatly affects the sense of realism of images.

Problems to be Solved by the Invention As mentioned above, in the current NTSC system, the aspect ratio of images is 4:3, and when broadcasting services such as movies, both sides are It can only be transmitted by cutting or compressing it vertically so that the horizontal direction of the effective screen matches the movie.

Therefore, there were problems such as loss of C = sense of place and reduction in screen area.

In view of the above-mentioned problems, the present invention provides a method for forming a television signal having a horizontally elongated aspect ratio while maintaining compatibility with the current NTSC television system.

Means for Solving the Problems In order to solve the above problems, the present invention separates an image signal with an aspect ratio larger than 4=3 into a main image signal and a sub-image signal, and converts the sub-image signal into a low-frequency signal. By separating the main image signal into a high-frequency component and a high-frequency component, time-axis multiplexing the low-frequency component, and frequency-axis multiplexing the high-frequency component, the main image signal is encoded in the NTSC system, thereby achieving compatibility with the current NTSC system. The present invention is provided with a method for forming a television signal that enables the transmission of a television signal containing image information with an aspect ratio larger than 4:3 while maintaining the aspect ratio.

Effect of the Invention The present invention makes it possible to form a television signal containing image information with an aspect ratio larger than 4:3 by the method described above, and in a television receiver, it is possible to form a television signal containing image information with an aspect ratio larger than 4:3.
It is possible to reproduce images with a wider aspect ratio than conventional NTSC television receivers, and
It is also possible to playback images with a conventional aspect ratio of 4:3 even when received on a second television receiver.

Embodiment Below, a method for forming a television signal according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing a method of forming a television signal in an embodiment of the present invention. In Figure 1, 1
is an input terminal for an image signal with an aspect ratio larger than 4:3, 2 is an image separation circuit, 3 is an NTSC encoder, 4
is an LPF (low-pass filter), 5 is a subtracter, 6 is a time-domain compression circuit, 7 is a time-domain expansion circuit, 8 is a time-domain multiplex circuit, 9 is a frequency-domain multiplex circuit, and 10 is based on the method of this embodiment. This is an output terminal for the formed television signal.

The method for forming a television signal using the configuration shown in FIG. 1 will be described below with reference to FIGS. 2, 3, 4, 5, and 6. First, FIG. 2 shows an image whose aspect ratio is larger than 4:3 which is input to the input terminal 1 of FIG.
The image separation circuit 2 separates the main image signal consisting of the image in the area with an aspect ratio of 4:3, indicated by M in the figure, and the sub-image signal consisting of the image in the area indicated by the hatched area (2). The main image signal is processed by the NTSC encoder 3.
The signal is encoded in the NTSC format and supplied to the time axis multiplexing circuit 8. The sub-image signal separated in the image separation circuit 2 is supplied to the LPF 4 and the subtracter 5. This sub-image signal has a waveform as shown in Fig. 3(a) on the time axis, and on the frequency axis, as a characteristic of the -C image signal, as shown in Fig. 4+al, the high frequency Shows a spectral distribution with low energy. The sub-image signal is processed by the LPF 4 and the subtractor 5 into low-frequency components with high energy (Fig. 3(b)
Figure 4 (frequency spectrum of BL) and high frequency components with relatively low energy (Figure 3 (waveform of DL).

The low frequency components shown in FIG. As shown in Figure 4 (C1), the time axis is compressed and supplied to the time axis multiplexing circuit 8. At this time, the frequency spectrum of the low frequency component can be transmitted using the NTSC system as shown in Figure 4 (C). In the time axis expansion circuit 7, the high frequency component shown in FIG. 3 (di) is time axis expanded as shown in FIG. At this time, the frequency spectrum of the high frequency component has a narrow bandwidth as shown in FIG. 4 (el). , during the vertical retrace period, etc., the low frequency components of the time-axis compressed sub-image signal are time-axis multiplexed and supplied to the frequency-axis multiplexing circuit 9. The high frequency component of the sub-image signal is NT shown in FIG.
After modulating and multiplexing so that the frequency interleaves and enters the 30 Hz gap in the spectrum of the SC signal,
It is output from the output terminal 10.

As described above, according to this embodiment, the sub-image signal is separated into low-frequency components and high-frequency components by the LPF and the subtracter, and the low-frequency components are compressed in the time axis and multiplexed into the narrow blanking period of the multiplexing area. In addition, if the energy of the multiplexed signal is large, interference occurs due to crosstalk to the luminance signal and chrominance signal.
By interleaving and multiplexing relatively low-energy high-frequency components into the gaps in the signal spectrum of the SC system, image information with an aspect ratio larger than 483 can be transmitted in a signal format that can be received by current NTSC television receivers. can be transmitted.

Note that although the LPF 4 in FIG. 1 has been described as one-dimensional, by making it a two-dimensional LPF, it is possible to separate high-frequency components and low-frequency components two-dimensionally. Also,
At this time, the time axis compression circuit 6 can perform two-dimensional compression, and the compression ratio can also be increased.

In addition, the format of the input image signal is an RGB signal (red signal,
The sub-image signal may be a low-frequency component or a low-frequency component depending on each signal. It is also possible to separate the high-frequency components into nine frequency components and time-axis multiplex them into the main image signal.

Effects of the Invention As described above, according to the present invention, when transmitting or servicing movies or programs with a sense of realism, images with an aspect ratio of 5:3, for example, are played back as they are on the receiver, so that the sense of realism is achieved. In addition, the intention of the program author can be fully conveyed, and it is compatible with current television (NTSC system).
Even when received by a receiver, it is possible to reproduce images with an aspect ratio of 4:3, and the interference is slight, making it extremely effective industrially.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a method for forming a television signal in an embodiment of the present invention, FIG. 2 is an image configuration diagram, and FIG.
is a signal waveform diagram showing the signal processing process in Fig. 1, and Fig. 4 (
a). fbl, (cl, +di, tel are frequency spectrum distribution diagrams showing the signal processing process in Figure 1, Figure 5 is a diagram of the principle of time axis multiplexing, and Figure 6 is a diagram of the principle of frequency axis multiplexing. 2. ...Image separation circuit, 3...NTSC
System encoder, 4...LPF, 5...
・Subtractor, 6... Time book compression circuit, 7...
...Time axis expansion circuit, 8...Time axis multiplexing circuit,
9... Frequency axis multiplex circuit. Name of agent: Patent attorney Toshio Nakao
- Figure 2 Figure 3 Figure 4

Claims (3)

[Claims] (1) Separate an image signal consisting of an image with an aspect ratio larger than 4:3 into a main image signal and a sub-image signal, separate the sub-image signal into a low-frequency component and a high-frequency component, and separate the sub-image signal into a low-frequency component and a high-frequency component. . A method of forming a television signal, characterized in that the low frequency component is multiplexed on the time axis, and the high frequency component is multiplexed on the frequency axis. (2) Forming a television signal according to claim (1), wherein the main image signal is time-axis multiplexed onto a signal encoded in the NTSC system after time-axis compression of low frequency components. Method. (3) A method for forming a television signal according to claim (2), characterized in that after time-axis expansion of high-frequency components, the main image signal is frequency-axis multiplexed onto a signal encoded in the NTSC system. .