JPS60192479A - Television signal receiver - Google Patents

Abstract

PURPOSE:To magnify automatically a picture with an especially small sized receiver by receiving a high definition television system signal, displaying the signal on a display means such as a cathode ray tube as it is and magnifying the picture based on information such as shape, position, magnification factor and shrinking factor. CONSTITUTION:In case of the four times magnification mode, a conversion region 42 comprising 858 picture elements and 562 lines being a half the original pattern (1,716 picture elements and 1,125 lines) is magnified two times into the original pattern (1,716 picture elements and 1,125 lines) in order to double the horizontal and vertical sides respectively. In taking the origin of the coordinate for the converted position as point 44 (0,0), the transmitted control position signal is (515,375) as shown in point 45 in Fig., which represents that the representative point of the conversion region exists at the horizontal 515th picture element and the vertical 375th line. As the signal representing the conversion position among the transmitted conversion control signal, the information to be converted into the standard television system is used as it is as position information.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is applicable to high-definition television broadcasting, etc., which transmits and displays images of higher quality than conventional standard televisions. A high-definition television signal that includes various control signals required when converting a television broadcast signal into a television signal of a standard format such as NTSC and displaying it on the screen of a television receiver of the standard format. This invention relates to a receiving device that makes original high-definition television images easier to view by utilizing the above.

Conventional configuration and its problems Current standard television system, namely NTSC.

High-definition television systems, which have more scanning lines, more frequency bands, etc. than systems such as PAL and IKGAM, have been proposed and are about to be put into practical use in Japan as well as in Europe and the United States. If a television broadcasting system different from the current standard television system is put into practical use, the problem will be that the standard television system receivers that are already in widespread use will not be able to handle high-definition television broadcasting as is. With this in mind, a high-definition television system that is compatible with the standard television system has been proposed. However, it naturally requires a certain degree of 3-by-7 compromise in order to achieve compatibility, and it has the disadvantage that it is difficult to obtain ideal image quality as a high-definition television system.

Furthermore, if the number of scanning lines, frequency band, color signal transmission method, etc. are completely unrelated to the current standard television system, ideal high-definition image quality can be obtained, but on the other hand, the standard television system If you try to watch the content on a TV receiver, you will need a lot of hardware for scan conversion and signal format conversion, which will significantly increase the cost of a signal conversion device or a receiver that can receive both formats. Become.

However, with recent advances in semiconductor memories, ICs, etc., and advances in digital signal processing technology, it is believed that the cost of the hardware for signal conversion and the like will be reduced to the extent that it can be put into practical use for consumer use in the near future. Therefore,
As a high-definition television signal, you can easily convert it to a standard television format or similar system on the receiver side without having to take compatibility into account, and you can enjoy a certain amount of content even if it is not a high-definition image. It is expected that this will be possible. As an example of conversion from a high-definition television signal to a standard television signal in this case, the scanning line 11
From a high-definition television signal with 26 lines and a 6:3 aspect ratio to 626 NTSC lines and a 4:3 aspect ratio.
The case of conversion to a standard television signal will be explained.

In Fig. 1, a, b, c, and d indicate four typical conversion modes, where 1 indicates a high-definition screen and 2 indicates an area of the high-definition screen to be converted to NTSC. ,3
shows a screen converted to NTSC. 4 is the number of scanning lines of the high-definition image, 6 is the number of pixels in the horizontal direction of the same image, 6
indicates the number of scanning lines in the area to be converted to NTSC, 7 indicates the number of pixels in the same area, 8 indicates the number of scanning lines in the image converted to NTSC, and 9 indicates the number of pixels in the image. Note that the numbers of scanning lines and pixels are shown for the entire area of each signal for ease of understanding, and in reality, processing is often performed using effective scanning lines and pixels excluding the blanking period. In the figure, a is the same-size conversion mode, and due to the difference in aspect ratio of both signals, the NTSC51;-n conversion screen 3 has the left and right sides of the original screen 1 cut down by about 20 degrees. b shows an example in which the conversion mode is 2 times enlarged, and C shows an example in which the conversion mode is 4 times enlarged. d is a somewhat special full-screen conversion mode in which the converted screen is distorted vertically so that there are no parts cut off at both ends due to the difference in aspect ratio. Usually, movies are displayed using standard television format. This corresponds to an example in which when broadcasting, etc., the characters on the screen are displayed in a vertically distorted manner so that they are not deleted in the title scene. In addition, a to d
In the above, the position of the conversion area 2 is such that a can be freely moved left and right, and b and c can be freely moved up, down, left and right. The number of scanning lines and pixels to be converted, the conversion mode, etc. are just one example, and it goes without saying that various other examples can be considered.

As explained above in Figure 1, when viewing high-definition images on a standard TV receiver, the viewer needs to switch between various modes and move the position appropriately depending on the content on the screen. . This is because if you were to watch the movie in fixed mode A, if very fine text appeared on a high-definition image, it would naturally become impossible to read it on the screen of a standard 6-vane semi-television receiver due to insufficient resolution. This is because it is necessary to change to mode b-4 or C, which is a useless enlargement mode. Therefore, instead of having the pleasure of freely manipulating the screen, viewers are forced to perform very complicated operations when viewing the screen normally, and they are forced to perform extremely complicated operations when viewing high-definition television images on a standard television receiver. Even if such adapters or converters become easily available, there is a risk that they will not become widely available.

Therefore, when converting a high-definition television signal to a standard television format equivalent television signal, information such as the shape of the picture frame, the position of the conversion area, the enlargement rate, the reduction rate, etc. A transmission method has been proposed in which the high-definition television signal is transmitted by means such as superimposing it on the blanking period of the signal, and the receiving side converts the high-definition television signal into a television system signal of the standard television system based on the information. There is. This will be explained below.

The feature of this transmission system is that information on the conversion mode and the position of the conversion area for each 7-basis as explained in Fig. 1 is transmitted from the high-definition television signal transmitting side such as the program producer. Even viewers who convert high-definition television signals using television receivers can view the program on the optimal screen as intended by program producers.

Moreover, if the viewer wishes, he or she can operate the switch as desired, and if such a control signal is not sent, the viewer can operate the screen in the appropriate mode as described above. The mode is automatically set to the standard image, that is, the mode shown in FIG.

However, the aspect ratio of this standard television system is 4:
3 and the aspect ratio of the high-definition television system is 5:3, which is a horizontally long screen.

If the aspect ratio relationship is reversed, there will be blank spaces at both ends of the converted image, but this is not a particular problem. Note that as the standard mode, in addition to the method shown in FIG. 1a, there may be a method in which the horizontal picture frame is set to exactly match the converted image. In this case, if the aspect ratio of the high-definition television signal is 6:3 and the aspect ratio of the converted image is 4:3, margins will appear at the top and bottom of the converted image. On the other hand, if the aspect ratio relationship is reversed, the top and bottom of the converted image will be slightly removed. In either case, there is no problem in standard mode. Strictly speaking, if margins appear at the top and bottom or left and right ends of the converted image, this corresponds to reduction.

An example of a control signal for controlling image conversion as described above will be explained.

First, four types of image conversion modes a to d in FIG. 1 are assumed. Therefore, 2 bits are required as a control signal. An example of this control signal is shown in FIG. In the figure, mode name a −
d corresponds to a to d in Figure 1.

Next, an example of a control signal indicating the position of the transformation area will be explained with reference to FIG. The figure is an example of conversion mode C, where 11 is a high-definition screen, 12 is a conversion area, and 13 is a coordinate when the high-definition screen has 1γ16 pixels horizontally and 1125 pixels vertically. , and 14 indicates a representative point indicating the position of the transformation area. Although the positions of 13 and 14 are set as shown in the figure for convenience, they are essentially the same no matter where they are set. In the example in Figure 3, point 14
The coordinates of the position are 870 pixels horizontally and 120 pixels vertically.

In this way, any location can be converted by transmitting the horizontal and vertical coordinate positions as control signals. Note that there are restrictions on the values that the above position coordinates can take depending on the type of mode.
In particular, the vertical gaps in mode a and the vertical and horizontal gaps in mode d are essentially blanking periods, so the conversion area cannot be moved to include them, and therefore they are fixed values. Also, if you select the upper left position as the representative point of the conversion area as in the case of Figure 3, 14, and take the coordinate value of the lower right corner of the high-definition image, a blanking period will appear on the converted screen, so this also applies. I can't take it. Therefore, the coordinate value is horizontal: 10 pixels) (=2 = 1o2oz (Ty1e pixel - 6
82 pixels)) Vertical: 10 bits [=2 = 1024) (
1126 lines - 626 lines)) The total is 20 bits of data.

The total data required for 1o vane image conversion is 22 bits including the 2 pits for the above mode, and this is done once per screen. In other words, it is sufficient to transmit the data once per frame. As an example of transmission, it is possible to transmit the signal together with various other digital information, such as a PGM audio signal, during the vertical blanking period. Alternatively, if there is sufficient horizontal blanking period, it may also be provided as a digital signal. Furthermore, even if it cannot be transmitted in the baseband state of the video signal, it may be sent on a separate carrier wave like audio in standard broadcasting systems, or it may be sent using a completely different transmission means.

Although the explanation has been given using four examples of image conversion modes a to d, except for d, which is a special screen, the rest are only different in magnification. Therefore, if this enlargement is performed continuously, a more effective converted screen can be obtained. For example, if you want to change in 32 steps, you will need 6 bits as a control signal, which means 2 bits in total including the position information and special conversion mode.
It is about 6 bits. To continuously enlarge an image at various ratios, calculations and interpolation are performed between multiple pixels and scanning lines according to the enlargement ratio, and the number of pixels is larger than the original number. This is possible by using a small number of pixels, and these techniques are already used in digital video effectors used in broadcasting stations and are generally known.

The control signals for conversion described above are effective when converting a high-definition television signal to a standard television system, etc., and are useful when viewing the original high-definition television receiver. It was completely meaningless to them.

Purpose of the Invention The present invention, as explained in the previous section, converts a control signal for converting a high-definition television signal into a standard television signal and displaying it on a standard television system receiver to convert it into a standard television receiver. The aim is to provide a function for automatically enlarging images, which is particularly useful for small TV receivers.

Structure of the Invention The high-definition television system is originally designed to display images on a large screen with a very realistic feeling, but if it becomes widespread in the future, it will naturally be used for personal use of 10 to 2 o.
A high-definition television receiver with a screen as small as the size of a small screen will also be needed.

In this case, if the normally sent screen was always displayed as it is, the small screen would make the fine details unreadable if viewed from a distance, even if the image is of high resolution. I have to get closer and look into the screen. Therefore, it would be very effective if the receiver had a function to enlarge the image as necessary. In this case as well, it would be very complicated if the viewer had to operate the child each time, so the present invention utilizes a control signal for image conversion included in a high-definition television signal to automatically convert the image. The objective is to be able to obtain enlarged images. of the present invention,
The difference from the conversion described in the conventional example is that the converted signal has the same aspect ratio and number of scanning lines as the original high-definition television signal, and the conversion mode is only enlarged image, and the first The image shown in Figure d is vertically 13,:,.

The point is that a conversion screen that changes to , in principle, does not occur. Therefore, when the conversion control signal indicates an unnecessary mode as shown in FIG. 1d, or when no control signal is transmitted, the normal image mode is automatically set.

Description of examples An explanation will be given below with reference to a block diagram of the embodiment shown in FIG.

21 is a high-definition television signal input terminal that receives and demodulates broadcasting to become a baseband signal; 22 is an A-D converter; 23 is a synchronization signal separation circuit; 24 is a clock generator synchronized with the synchronization signal; Reference numeral 26 denotes a circuit for extracting the conversion control signal, and in this embodiment, the circuit is inserted into a horizontal or vertical blanking period of the input signal. 2
6 is a circuit that determines whether the extracted conversion control signal is necessary or unnecessary; for example, in the conventional example shown in FIGS. 1 and 2.
Control signals such as a and d in the figure are determined to be unnecessary, and are replaced with control signals for modes in which no conversion is performed in the receiver of this embodiment. The same operation is performed even when, for example, the received high-definition television signal does not include a conversion control signal.

Reference numeral 27 denotes a manual operation device, which generates a control signal for enlargement when the viewer wants to manually convert to various enlarged screens. It is possible to switch between automatically obtaining an enlarged screen using a control signal in the television signal, or manually obtaining a desired enlarged screen.29
is a line memory that stores television signals for several horizontal scanning periods (horizontal scanning period is abbreviated as H hereafter).For example, in the 4x enlargement mode, it is sufficient to double the horizontal and vertical signals. An operation is performed in which the time axis is expanded to double the period of one half of the signal. 3o is a circuit that processes signals for conversion, and when writing the signal read from the line memory to the next stage frame memory 31, for example, in the 4x enlargement mode, the signal for 1H is duplicated in 2H of the frame memory. If you write in it, it will also be enlarged twice in the vertical direction. Reference numeral 31 is a frame memory for storing signals for one screen (15 bases), and along with the line memory 29, writing and reading thereof are controlled by a memory control 32.
This is done using an address signal generated by 33
34 is a D-A converter for converting the digital image signal read out from the frame memory into an analog high-definition television signal, and 34 is a high-definition television receiver for supplying the signal to the video input terminal of the receiver. This is a signal output terminal.

Note that in reality, a signal processing circuit such as an encoder may be required to match the input signal specifications of the display side. Since all the detailed techniques of the block diagram explained in FIG. 4 are well known, explanations of individual contents will be omitted. In addition, the circuit of the embodiment shown in Fig. 4 needs to have an optimal configuration according to the specifications of the input high-definition television signal.For example, if the input signal is an R-G-B three primary color signal, three systems are required. etc.

FIG. 5 describes the conversion area for actual image conversion, taking the 4x enlargement mode as an example. In the figure, 41 indicates the entire range of the original input signal. As explained in the section on the conventional example, in reality, signal processing may be performed on the scanning lines and pixels of the effective scanning portion. 42 indicates an area to be enlarged and converted. In the 4x enlargement mode, in order to double the horizontal and vertical dimensions, the original screen's 1716 pixels and 1126 lines must be half each.
The conversion area 42 of 858 pixels and 662 lines is respectively enlarged twice by the circuit of the embodiment explained in FIG. be. 44 in the same figure shows a point assumed to be the origin of the coordinates indicating the converted position, and if this is set as (0, 0), the sent control position signal will be as shown in 45 in the example of FIG. 6 (ts15 376), which indicates that there is a representative point of the 0 conversion area at the 615th horizontal pixel and the 376th vertical pixel. Among the transmitted conversion control signals, the signal indicating the conversion position can be used as the position information in the present invention, as is the information for converting to the original standard television system. However, if the representative point of the transformation area is
Strictly speaking, if it were to be used as is, the converted image vane would be positioned slightly to the right when it is in a position as shown in 5. This is because the position coordinates were originally determined assuming a conversion that would result in an aspect ratio of 4:3.If this value is used for a converted image with an aspect ratio of 5:3, for example, the horizontal coordinates It is necessary to devise measures such as subtracting the transmitted numerical value from the transmitted numerical value by a constant value. Comparing the example in Figure 6 with the example in Figure 3, (6:3 horizontal pixel count (858) - 4:3 horizontal pixel count (ea2))/2 = ssj surface element square 88 pixels It can be seen that is the value to be subtracted in this example. Note that similar operations may also be required in the vertical direction.

Next, when the number of scanning lines and the number of pixels are doubled in the example of FIG. 6, the number of scanning lines is doubled in the example of FIG.

This is done by using each pixel twice twice, but other methods do not simply use it twice, but interpolate it by calculation with adjacent scanning lines or pixels to obtain smooth connections. It is also possible to do so. For example, when obtaining 3 pixels from 2 pixels, or more complicatedly, by performing interpolation operations such as creating 18 pixels from 5 pixels, or 9 pixels from 5 pixels, etc. This is also necessary when the magnification is continuously changed.

As explained in the conventional example, these techniques are already used in digital video effectors and the like and are well known. Furthermore, the circuit described in this embodiment can be configured in various ways, such as when it is configured as a stand-alone adapter or when it is configured by being incorporated into a high-definition receiver. Furthermore, it is clear that the present invention is not particularly limited to the 1126-line high-definition television system, but can be applied to conversion between various other television systems.

Effects of the Invention When high-definition television broadcasting is put into practical use, the signal will be converted in advance to the optimal conversion format so that the content can be viewed on standard television receivers that are already in widespread use. Nodame's method of transmitting control signals actively utilizes control signals that are normally useless for high-definition television receivers.
Towards par 19 in the future - 7 When compact high-definition color television receivers for internal use become widespread, it will be possible to obtain powerful images even on small screens without bothering the viewer, and furthermore, it will not be limited to small TV receivers. Even if the same action is performed on a large screen display, a more dynamic screen can be obtained, and the intention of the program director can be accurately conveyed to the viewers.

[Brief explanation of drawings]

Fig. 1 is a diagram showing an example of image conversion in the conventional example, Fig. 2 is a diagram showing an example of a control signal for the image conversion mode in the conventional example, and Fig. 3 is a diagram showing the position of the conversion area in the conventional image conversion. FIG. 4 is a block diagram of a television signal receiving device according to an embodiment of the present invention. FIG. It is a figure explaining an example. 21...High-definition television signal input terminal,
26... Control signal extraction circuit, 26... Control signal sequence... Conversion signal output terminal, 41... Entire area of input signal, 42... Enlargement conversion Area to do, 4
3... Screen that has been enlarged and converted, 44... Origin of converted position coordinates, 46... Representative point and position coordinates of converted area.

Claims (1)

[Claims] The shape of the image frame required when converting a high-definition television system signal, which has a greater number of scanning lines, frequency bandwidth, and number of pixels, etc. than the standard television system, to a television system signal such as the standard television system. , position of transformation area, magnification rate,
A high-definition television system signal having information such as a reduction ratio is received, and the high-definition television signal is displayed as it is on a display means such as a cathode ray tube, and the image is enlarged based on the information. Features: Bulky #Soodori television signal receiving device/