JPS6313590A - High definition television system - Google Patents

Abstract

PURPOSE:To obtain high fidelity pictures in all by segmenting a picture screen into plural blocks and broadcasting only the blocks including detailed components of a picture at high fidelity. CONSTITUTION:A video signal is split into a luminance signal component Y and chromaticity signal components I and Q. The high frequency component of the luminance signal component Y is extracted by a 4.2 mHz high pass filter 16. The screen is segmented into 240 X120 blocks, for example, and data in an image memory 18 is read by the blocks. If a read-out signal includes a strong component exceeding a prescribed level, a high frequency component detection circuit 19 tarnsmits a signal opening a gate 20. A transmission data generation part 22 temporarily accumulates transmitted block-by-block data on high frequency components in a data memory 24, inspects the accumulated data, and selects the 100 blocks requiring high frequency compensation. A mixer 14 mixes the selected blocks with a color video signal and broadcasts them.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a television system, in particular, multiplexes high-frequency components of a luminance signal or a chromaticity signal onto a television signal according to a standard system, and transmits the multiplexed signal. On the receiving side, the present invention relates to a method for obtaining an image with improved fidelity based on the above-mentioned high frequency components.

<Conventional technology> In the standard system (NTSC system), the bandwidth of the luminance signal is 4
．． The bandwidth of chromaticity signal processing is about 2 MHz, 1.5 MHz.
The bandwidth of the chromaticity signal Q is limited to about 0.5 MHz.

<Problems to be Solved by the Invention> Most of the current television broadcasting equipment has a wide bandwidth that far exceeds the above-mentioned bandwidth. Therefore,
If a raw video signal is displayed on a video tube without being transmitted over radio waves, it is possible to display an extremely fine image with well over 700 pixels per horizontal scanning line. Despite this, once a broadcast image is received on radio waves,
Because the luminance signal is limited to about 4.2 MHz due to radio wave bandwidth, the resolution is reduced to about 480 pixels corresponding to a horizontal scanning line, and research is being conducted to improve this. Similarly, for the chromaticity signal, the ■ component is 1.5 M
It is recognized that it is either limited to about Hz or that it is necessary to expand this as the display brightness of picture tubes has recently improved. Also,
The Q component of the chromaticity signal is limited to about 0.5 MHz, and it has been argued that this is too low compared to the bandwidth of current technology components.

In order to transmit the missing luminance signal or chromaticity signal mentioned above within the current broadcast radio wave band, the only way to transmit the missing information is to multiplex the missing information onto the current broadcast radio wave. Multiplexing using a carrier wave or the like may reduce image quality, and most of the vertical retrace period is already used for teletext broadcasting, test signal transmission, etc.

Therefore, it is an object of the present invention to multiplex signals for improving image resolution, color fidelity, etc. outside the image display period and during periods when teletext broadcasting and the like are not being performed.

<Means for Solving the Problems> The system according to the present invention is composed of a transmitting device and a receiving device.

In the transmitter, while creating a color television signal using the standard method (N'rsc method), for parts of the image that require improvement in image quality, high-frequency component data for improving the image quality is added to the color television signal. to multiplex. These high-frequency components for improving image quality are those with frequencies exceeding 4.2 MHz for luminance signals, and those with frequencies of 1.5 MI-IZ and 0 for chromatic signal processing and Q, respectively.
．． This refers to the part exceeding 5 MHz. To do this, first, high-frequency components that could not be added to the color television signal are separated. The image screen is divided into a large number of blocks each consisting of a relatively small number of pixels, and an adreno is set for each block. The above-mentioned high-frequency component is once stored in a memory together with the address data, and then it is checked whether or not transmission is necessary, and the high-frequency component data of the necessary block is read out together with the address data. The read address data is multiplexed and transmitted on the horizontal scanning line during the retrace period of the color television signal, and the read high frequency component data is transmitted in an analog state on the horizontal scanning line of the color television signal. It is multiplexed and transmitted on the front porch of the synchronization signal.

Regarding division into blocks, (a) 4 pixels constitute 1 block, 180 horizontal pixels x 48 vertical pixels.
Classify into 0 categories.

(b) 3 pixels as 1 block, 240 pixels horizontally x 48 pixels vertically
Classify into 0 categories.

(c) 3 pixels horizontally x 4 scanning lines vertically (12 pixels) are organized into l blocks and divided into 240 horizontally x 120 vertically.

Examples include:

Technically, the 10th horizontal scanning line during the vertical retrace period is
Although the 21st horizontal scanning line can be used, the 14th to 21st horizontal scanning lines are already used for teletext, test signals, etc. The number of parnus that can be superimposed on one horizontal scanning line is 300 to 400 barnus, and if the adreno signal is 8 bits per block, it is necessary to devise a modulation method etc. to see if it can accommodate 50 blocks worth of address data. For example, it can accommodate up to about 100 blocks.

The front porch of the horizontal synchronization signal is not wide enough to accommodate only a few pixels (for example, 6 pixels), but since there are approximately 240 horizontal synchronization signals in one field, the total number of horizontal synchronization signals is approximately 1440. Transmission for pixels becomes possible. Here, since digitizing the signal requires several bits per pixel, it is transmitted in an analog state.

The criteria for checking whether each block needs to be transmitted is 50 to 250 per field in order of the amount of high frequency information.
This selection may be performed by selecting blocks, degrees, or focusing on the central part of the screen.

When the storage of the high-frequency component data and address data of these blocks for one field is completed, the inspection is performed in the first half of the following vertical retrace period, and the address data of the selected block is read out in the second half. It is advantageous to sequentially read out the high frequency component data in synchronization with the horizontal synchronizing signal front porch within the image period of the next one field. Naturally, while high frequency component data is being read, high frequency component data and address data for the field at that time are generated and stored. It is advantageous to compress the read address data by using full-length representation or the like.

The receiving device processes the received signal to extract a normal color television signal and separates components related to high frequency information. The high frequency component data among the separated components is written into the image memory, and the writing position is the position indicated by the address data. Next, the stored contents of this memory are read out in synchronization with the color television signal and added to the color television signal.

<Operation> The image screen is divided into many blocks (for example, 240 x 120
= 28,800 blocks) and consider each block, it is not necessary to display all blocks with high fidelity to obtain a high-fidelity image. By displaying only blocks containing a large amount of , with high fidelity, an image with sufficient fidelity as a whole can be obtained, even if the remaining blocks have low fidelity.

In this invention, a limited number of blocks (e.g. 1
00 to 500 block) to obtain high fidelity, this greatly improves the fidelity of the entire image.

Furthermore, when receiving with currently popular television receivers, high-frequency information is simply not available, and the image can be received without any problems, thus achieving compatibility.

<Example> FIG. 1 shows a transmitting device, and FIG. 2 shows a receiving device.

In FIG. 1, a video signal obtained by a color camera 1 is divided into a luminance signal component Y and a chromaticity signal component Q by a matrix circuit 2, and the luminance signal component Y is filtered by a 4.2 MHz low-pass filter 3. After the frequency components are removed, only the low frequency component data is digitized by the AD converter 4 and temporarily stored in the image memory 5.

The accumulated data is read out after an appropriate time, converted back to an analog signal by the DA converter 6, and sent to the color encoder 7.

On the other hand, the chromaticity signal components (2) and (Q) separated by the matrix circuit 2 are also digitized by AD converters 8 and 9 and stored in image memories 10 and 11, respectively, and read out after an appropriate time and sent to the DA converters. The signals are returned to analog signals at 12 and 13 and sent to the color encoder 7.

The color encoder 7 synthesizes an NTSO color video signal based on the low frequency (o) component data of the luminance signal Y and the chromaticity signal component processing and Q, and this color video signal is converted into a synchronization signal by a mixer 14. It is combined with other necessary signals and broadcasted as a broadcast radio wave by the transmitter 15. The color video signal produced by this color encoder 7 is virtually the same as the color video signal in the conventionally broadcast color television signal.

The luminance signal component Y is also supplied to a 4.2 MHz high-pass filter 16, where high-pass component data not transmitted in conventional color television broadcasting is extracted. This high frequency component data is digitized by an AD converter 17 and temporarily stored in an image memory 18.

The screen is, for example, every 12 pixels (240 horizontal x 120 vertical)
The image memo jJ18 is read out sequentially one block at a time. High frequency detection circuit 19
checks each block to see if the readout signal contains a component with an intensity exceeding a predetermined level, and if a component exceeding a predetermined level is present, tests the next block. During this time, a signal is sent to open the gate 20. Reference numeral 21 denotes a simple delay circuit using, for example, a shift register, which delays the readout signal of the D image memory 18 by a time corresponding to one block. The data is sent to the transmission data creation section 22 through a gate 20 whose opening/closing is controlled by a gate 20.An address counter 23 sequentially counts the blocks and sends this counted value to the transmission data creation section 22 as block address data.

The transmission data creation section 22 temporarily stores the sent high frequency component data for each block in the data memory 24 together with 8-bit address data. Then, during the vertical synchronization signal and equalization bulk period (1st to 10th horizontal scanning line period) after one field of image signals is finished, the accumulated data is inspected to identify 100 blocks that require high-frequency compensation. Select. For the selected blocks, the address data is read out continuously during the following 11th and 12th horizontal scanning line periods, and the high frequency component data for each block is read out during the front porch period of the horizontal synchronizing signal of the following image signal period. Read out each pixel. Of course, on the other hand, high-frequency component data for each block is taken in through the game controller 20, and address data from the address counter 23 is also taken in. The criteria for selecting the 100 blocks described above can be determined by the order of the blocks containing a large amount of high-frequency components, or by placing the emphasis on the center of the screen, and a computer is used for this purpose.

The read high frequency component data and address data are separated in a separator 25, the address data is converted into serial data in a serial data section 26, and furthermore, in a compression section 27, the Fullengunu expression area component data is converted into DA.
In the converter 28, the image memories 5 and 18 are mixed in the mixer 14 so that the address data matches the 11th and 12th horizontal scanning lines of the color video signal, and the high frequency component data is the color image signal. The readout timing is determined to match the horizontal front porch of the video signal.

In FIG. 2, the received and detected signals are separated into a color broadcast signal and a color broadcast signal. The color video signal is divided into a luminance signal component Y and chromaticity signal components 2 and Q in a color decoder 31, and AD converters 32 and 33 respectively.
and digitized at 34, and then stored in image memory 35
．． 36 and 37.

The luminance signal component Y stored in the image memory 35 is read out at an appropriate time, passes through the adder 38, and is sent to the DA converter 3.
The signal is analogized at 9 and supplied to a matrix 40. The chromaticity signal components (1) and (Q) stored in the image memories 36 and 37 are read out in synchronization with the readout of the image memory 35, converted into analog signals by DA converters 41 and 42, respectively, and then supplied to the IJ controller 40. Ru. The matrix 40 reproduces color signals from the supplied luminance signal component Y and chromaticity signal components and Q, while the high frequency component data separated by the separator 30 is digitized by the ΔAD converter 44, The address data in the image memory 45 is written to the specified position. This high-frequency component data is read out in synchronization with the readout of the image memory 35, and both read data are added in an adder circuit 38, and then converted into analog data in a DA converter 39.

Therefore, the luminance signal component Y outputted from the adder circuit 38 and converted into an analog signal by the DA converter 39 has its resolution enhanced for blocks requiring high resolution. Therefore, the resolution of the image displayed on the picture tube is increased at key points, resulting in an overall high-resolution image.

Note that although the above embodiment aims to increase the resolution by enhancing the luminance signal, the present invention can be similarly implemented to increase the color definition by enhancing the chromaticity signal or Q. can.

<Effects of the Invention> As described above, according to the present invention, it is possible to send and receive high-fidelity images, which was previously impossible to send and receive, even though radio waves with the same bandwidth as before are used. can. Moreover, if the broadcast is received by a conventional receiving device,
It is simply not possible to obtain high fidelity, and it is possible to receive an image with the same fidelity as the conventional method, so transmission according to the present invention can be started without any problems.

[Brief explanation of drawings]

The figures show an embodiment of the invention, with FIG. 1 being a block diagram of a transmitting device and FIG. 2 being a block diagram of a receiving device. 1 to 13... Standard color television signal generation means, 14... Mixer (part of multiplex transmission means), 16.
. . . High-pass filter, 22 . . . Transmission data creation section (means for selecting a block), 23 .
Adder (means for adding), 43...Picture tube, 45...
・Image memory. Patent applicant: Nippon Television Broadcasting Network Co., Ltd. Representative: Tetsu Shimizu and 2 other people 1 Figure

Claims (1)

[Claims] (1) Consisting of a standard color television transmitting device and its receiving device, the transmitting device includes means for generating a standard color television signal, and a video signal that cannot be included in the color television signal. means for extracting the high frequency component of the image; means for dividing the screen into a plurality of blocks each consisting of a relatively small number of pixels and sequentially assigning an address to each block; and means for selecting a block to which the high frequency component needs to be transmitted. and means for multiplexing the address data of the selected block on the horizontal scanning line within the retrace period of the color television signal; means for sequentially multiplexing analog data of the high-frequency components of the selected blocks, and the receiving device includes means for separating the received signal into the color television signal, the address data, and the high-frequency component data , means for writing the separated high frequency component data in a position specified by the address data in the image memory; and means for reading out the image memory in synchronization with the separated color television signal to read the high frequency component data read out from the image memory. A high-fidelity television system comprising means for adding component data thereto, and a video tube for displaying a color image based on the color television signal to which component data has been added.