JPH01229577A - Divided television signal transmitter and receiver - Google Patents

Abstract

PURPOSE:To secure a signal/noise ratio(S/N) when the additional signals are received and reproduced by transmitting these additional signals after converting into the non-interlace signals having 525 scan lines and the 30Hz frame frequency vie the frame thinning operation. CONSTITUTION:The additional signals are transmitted at the transmission side with one frame thinned every two frames. At the reception side the signals of the thinned frames are interpolated with the received additional signals and, at the same time, the degrees of attenuation of these interpolated signals are controlled by the movements of pictures. In such a way, since the quantity of information is reduced by the frame thinning operation at transmission of the additional signals, disturbance of the additional signals can be reduced to a primary signal. Furthermore the information lost by the frame thinning operation is supplemented by the frame interpolation at the reception side. Therefore it is possible to avoid the flicker produced in a large area and to eliminate the deterioration of a screen.

Description

[Detailed Description of the Invention] [Purpose of the Invention (Field of Industrial Application) This invention provides a color television for expanding the screen aspect ratio while maintaining compatibility with an NTSC color television broadcasting system. The present invention relates to a transmission device and a reception device suitable for multiplexing a signal into an original color television signal and transmitting the multiplexed signal.

(Prior Art) The NTSC system, which is one of the color television broadcasting systems, can be said to be an excellent system that is compatible with black and white television broadcasting and has sufficient performance as a color television broadcasting system. This can be seen from the results of implementation in Japan, the United States, and other countries.

Incidentally, over its long history, the image quality of the NTSC system has been significantly improved since its initial implementation as a result of constant efforts by both the transmitting and receiving sides.

However, in the NTSC system, there is a desire for further improvement in image quality due to the recent spread of large screen displays.

IDT is a method for improving the image quality of the NTSC system.
V (Improved Derlnition T
There is a method called e1evision). This method aims to improve image quality by making full use of the transmitted NTSC color television signal (hereinafter referred to as NTSC signal) on the receiving side.

This IDTV could not be implemented under conventional analog technology, but has become possible due to recent advances in digital technology.

According to this IDTV, compared to the conventional analog system,
Image quality can be significantly improved.

However, since this IDTV is based on the NTSC system, the upper limit of the image quality that can be improved is limited by the NTSC standard. Here, the upper limit items for the system include (1) aspect ratio (2) horizontal resolution of 330 Tv lines.

The aspect ratio of (1) is currently 4:3, but it is known that users prefer ratios such as 523 or 6:3 (Broadcasting System published by Japan Broadcasting Publishing Association (Editor) (See page 80 of 2 Japan Broadcasting Corporation)).

In addition, the high-definition television broadcasting system (HighDef'
1nition Te1evis1on), 16
:9 aspect ratio may be adopted (CCI
RReport 801-2).

Regarding the horizontal resolution (2), in the NTSC system, 4
．． Since it is specified as 2MHz, the limit is 330Tv. On the other hand, considering the number of effective scanning lines (480 lines), a vertical resolution of 450 TV lines is possible even when considering margins such as overscan. Therefore, at this stage, it is desired to improve the horizontal resolution in terms of horizontal and vertical balance.

As an example of a method that improves the above two items and maintains compatibility with current television receivers, for example, Jose
ph L, LoClcero “A Compati
ble Hlgh-Deflnition telev
islon System (SLSC) withC
rominance and aspect rat
io Inpurveients'”5VPTE J
oural, May 1985. This 5LSC method will be described below.

FIG. 18 shows a spectrum diagram of the 5LSC method.

In FIG. 18, signals of 0 to 4, 2 MHz are signals for maintaining compatibility with current television receivers. The 4.9-10.1 MHz signal is an additional signal used to expand the aspect ratio and the resolution of one luminance and one chromaticity. Therefore, in this 5LSC system, the signal for one station is transmitted using the band for two channels, and one channel basically transmits a signal similar to the current television broadcast signal, and the other channel transmits a signal that is basically similar to the current television broadcast signal. , and sends additional signals to improve image quality.

According to such a configuration, channels received by current television receivers do not include additional signals, so
It is considered that there is high compatibility with respect to interference. However, 1
It is not efficient because it occupies two channels per station. Particularly in situations where channel allocation is near the limit, such as in Japan, implementation is expected to be difficult. In addition, when considering intra-station and inter-station transmission, current television broadcasting equipment is
Since it does not have a band that extends to 0 MHz, it is necessary to invest in all new equipment.

From the above, it is preferable to perform transmission within the band of one channel. Moreover, if additional signals can be multiplexed around the baseband of 4.2 MHz, compatibility with current television broadcast equipment such as video tape recorders and transmitters can be achieved.

As one method of multiplexing additional signals to around 4.2 MHz of the baseband, T.Fukinuki et al.

”Extended Derlnjslon TV
Fully compatible with E
xlsting 5standards-JEERTr
, onCommunication Vol, C0M-
32 NO, 8, August 1984.

In the NTSC system, in the case of still images, this method uses luminance detail components (approximately 4 to
This is a 6 MHz signal, and is used to multiplex YH (hereinafter referred to as a luminance high frequency signal). Here, the unused area is
In the vertical-time direction spectrum diagram of FIG. The area of the third quadrant is used. In addition, in the figure, C
is a color difference signal.

By the way, this method is applicable only to still images and not to moving images. In the case of video, the spectrum spreads in the time direction and the original NTS
Since the C signal and the additional signal (luminance high frequency signal Yo) overlap,
This is because it becomes impossible to separate both signals on the receiving side.

Since the brightness high frequency signal YH is effective for still images, even if the above method can transmit the additional signal only for still images, the objective of improving the resolution of still images can be achieved.

However, when transmitting a signal for enlarging the aspect ratio as an additional signal, the additional signal must be sent not only for still images but also for moving images. Therefore, the above-mentioned additional signal multiplexing method, which can transmit additional signals only for still images, cannot be used to transmit additional signals for expanding the aspect ratio.

In order to solve this problem, it may be possible to limit the motion component of the current NTSC signal, but doing so would likely cause unnatural motion as a side effect, and the existing television reception Compatibility with the machine will be impaired.

Furthermore, since the luminance high frequency signal YH has a much lower level than the low frequency component in the case of a general natural image, even if it is multiplexed, there is little interference with current television receivers. On the other hand, when transmitting an additional signal for expanding the aspect ratio, it is necessary to transmit from high-level low-frequency components to high-frequency components, which poses a problem of interference with the current NTSC signal. In order to solve this problem, it is possible to lower the transmission level of the additional signal, but if this is done, a new essential problem arises in that the signal-to-noise ratio during reception and reproduction deteriorates.

As mentioned above, in order to multiplex an additional signal to expand the aspect ratio within 4.2MHz of the baseband, it is necessary to: ■ Be able to transmit the additional signal regardless of whether it is a moving image or a still image ■ Current televisions It is necessary to satisfy the following conditions: there is little interference to the John receiver, and the signal-to-noise ratio (S/N ratio) during reception and reproduction of the additional signal can be secured. However, at present, no method has been developed that can satisfy these two conditions.

(Problems to be Solved by the Invention) As described above, in the conventional additional signal multiplexing color television transmission device that is compatible with the NTSC color television broadcasting system, one broadcasting channel (6MHz) and can transmit color television signals for additional information within the baseband (4.2 MHz) band, but this is limited to still images or transmitting only high-frequency components; It was not possible to transmit additional signals when transmitting low frequency components.

This invention was made to specifically solve problem (2) among the above problems, and it is possible to transmit and receive the additional signal for wide aspect ratio without degrading the original NTSC signal or the quality of the original NTSC signal. The purpose is to provide a transmission device and a reception device that can

[Structure of the Invention] (Means for Solving the Problem) In order to achieve the above object, the present invention provides a non-interlaced signal with an aspect ratio of 16:9 or 5:3.
In a split television signal transmission device that transmits and receives the main signal that displays the center part of the screen with an aspect ratio of 4=3 and the additional signal that displays the side part of the screen excluding the center part of the screen, the additional signal is sent and received. On the side, one frame is thinned out every two frames and transmitted, and on the receiving side, the received additional signal is used to interpolate the signal of the thinned out frame, and the amount of attenuation of this interpolated signal is adjusted according to the movement of the image. It was designed to be controlled.

(Function) According to the above configuration, since the amount of information is reduced by frame thinning when transmitting the additional signal, interference of the additional signal with respect to the main signal can be minimized.

On the other hand, on the receiving side, the information lost due to frame thinning is interpolated using frame interpolation.

The occurrence of large-area flicker can be prevented, and deterioration of still images can be eliminated. In the case of videos, the interpolated frames will cause some unnaturalness in the movement, especially at the edges, but the high-frequency range of the interpolated signal is attenuated, so
This unnaturalness can be reduced.

(Embodiments) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a circuit diagram showing the configuration of a transmission device according to an embodiment of the present invention. FIG. 2 is a circuit diagram similarly showing the configuration of the receiving device.

Before explaining the transmission apparatus of FIG. 1, a transmission system to which the present invention is applied will be explained using FIGS. 3 to 12.

In FIG. 3, 11 is an input terminal for color television signals. This signal has an aspect ratio of 16:9,
This is a sequential scanning (non-interlaced) signal with 525 scanning lines and a frame frequency of 60 Hz. In the drawings, such non-interlaced signals are expressed as 526/60.

This signal consists of a luminance signal represented by Y and color difference signals represented by I and Q.

The signal supplied to the input terminal 11 is sent to the screen division filter 1.
2. This screen division filter 12 divides the input signal into a portion corresponding to the center portion F1 of the screen F in FIG. 4 and a portion corresponding to the side portion F2. Here, the aspect ratio of the screen center portion Fl is set to 4:3.

Screen center portion F1 output from the screen division filter 12
The signal (hereinafter referred to as the center signal) is sent to the time expansion circuit 1.
3, and the time axis is expanded by 5/4 times. on the other hand,
The signal of the screen side portion F2 (hereinafter referred to as side signal) is expanded four times by the time expansion circuit 14. Figure 5 shows the state of time expansion. Of the effective horizontal scanning period 53AtS in terms of interlace, 42 μs is allocated to the screen center portion Fl, and 11 μs is allocated to the screen side portion F2. This relationship is (42 + 11): 42x (3/4) - 5: 3, which basically corresponds to an aspect ratio of 5:3, but in normal television receivers, overscan is involved. , it is possible to support an aspect ratio of 16:9, assuming an overscan of about 6%.

Hereinafter, the description will be made using parameters based on the relationship shown in FIG. 5, but if you do not want to allow overscanning, the parameters described below may be slightly changed.

The center signal is time-expanded by a factor of 5/4, resulting in a band of 0 to 10 MHz. Among the time-expanded center signals, the luminance signal Y is supplied to the luminance high frequency separation circuit 15. This brightness high frequency separation circuit 15 receives input signals from 8 to 8.
It is separated into a luminance high frequency signal Yo of 10 MHz and a luminance low frequency signal YL of 0 to 8 MHz.

The luminance high frequency signal Y 11 has its level suppressed by a level conversion circuit 16 and is then converted by a Y□ encoder 17 into a signal suitable for multiplexing. On the other hand, the luminance low-frequency signal)' is supplied to the NTSC enhancer 19 after being subjected to blurring processing in the motion adaptive blurring processing circuit 18 to make it a signal suitable for multiplexing with the luminance high-frequency signal YH and the side signal. be done. At this time, the spectrum of the luminance low-frequency component YL is limited to a region as shown in FIG. 6(a).

Of the center signals output from the time expansion circuit 13, the chromaticity signal 1. Q is NTSC with color difference band limiting filter 20
After being limited to a band that meets the standard, it is supplied to the NTSC encoder 19. And this NTSC encoder 1
9, the luminance low frequency signal YL is converted into an NTSC color television signal, and then the addition circuit 21
is supplied to

On the other hand, the side signal is time-expanded four times by the time expansion circuit 14, and is made into a signal with a band of 2.2 MHz.

This time-expanded side signal is sent to the time-division color multiplexing circuit 22.
is supplied to This time-division color multiplexing circuit 22 receives chromaticity signals 1. After band-limiting Q to 0.25 MHz, line sequential multiplexing is performed. Furthermore, by time-division multiplexing this line-sequential multiplexed signal and the luminance signal Y, the signal shown in FIG. 5 is obtained. In this case, the chromaticity signal I.

The amplitude of Q is set to 1.33 (110,75) times the normal value. This makes it possible to improve the S/N ratio on the receiving side.

The output of the time-division color multiplexing circuit 22 is outputted by the band compression circuit 23 at 1/30 [second] and 525/4 [in the vertical direction].
C, p, h, and horizontal directions are compressed to a band of 1 [M7]. The level of this compressed output is suppressed by the level conversion circuit 24, and then converted by the side information encoder 25 into a signal suitable for multiplexing. The spectrum of this converted signal is located in the shaded area in FIGS. 6(a) and (b), and as shown in FIG. 6(a), the center signal is
They are separated in the horizontal and vertical spectral regions.

The output of the side information encoder 25 is supplied to the adder circuit 21 and added to the output of the NTSC encoder 19.

This addition output is sent to Y by the addition circuit 26, and the encoder 1
It is added to the luminance high frequency signal Y output from 7. This addition output becomes a transmission signal.

FIG. 8 is a circuit diagram showing an example of a specific configuration of the motion adaptive blurring processing circuit 18.

In this FIG. 8, a luminance low frequency signal YL having a band of 0 to 8 MHz is supplied to the input terminal 1b from the luminance high frequency separation circuit 15 shown in FIG. 1 above.

This luminance low-pass signal Y is supplied to a horizontal and vertical two-dimensional low-pass filter (hereinafter referred to as LPF) 2b, which has the shaded area in FIG. 6(a) outside the passband. Area components are removed. This diagonal high-frequency component has little contribution to visual perception, so even if it is deleted, it has almost no effect on deterioration of image quality.

The output of the two-dimensional LPF 2b is supplied to the horizontal HPF 3b, and high frequency components of 4 to 8 MHz are extracted.

This high frequency component of 4 to 8 MHz is subjected to motion adaptive blurring processing. That is, this 4-8 MHz component is supplied to a still image processing circuit 4b and a non-interlace/interlace (hereinafter referred to as NINT/INT) conversion circuit 6b. As shown in FIG. 9, the still image processing circuit 4b has a frame delay circuit 1c that delays the input signal by one frame, and an adder circuit 2c calculates the sum of the input and output signals of this frame delay circuit IC. , the output signal of this adder circuit 2c is halved by a 1/2 coefficient circuit 2C. As a result, an average output of image signals for two frames (in this case, image signals at 1/30 second intervals) is obtained from the 1/2 coefficient circuit 3C.

This average output is supplied to the NINT/INT conversion circuit 5b and converted into an interlaced signal. This NINT
The /INT conversion circuit 5b has a line distribution circuit 1d, as shown in FIG. 10, and the line distribution circuit 1d distributes one frame's worth of signals into signals of odd lines and even lines.

Then, the signal on one line is transferred to the field delay circuit 2d.
By selectively selecting this signal and the signal on the other line by the switch circuit 3d in accordance with the field switching signal, an interlaced signal is obtained. Here, the output signal of the switch circuit 3d is
Although the signal is in the form of an interlaced signal, since the information for one frame is divided into two fields and transmitted, there is no motion component between the two fields.

Therefore, there is no generation of vertical high-frequency components due to so-called interlace folding that occurs when there is movement, so there is no worry of crosstalk to additional signals.

The above NINT/ to which the output of the above horizontal HPF 3b is supplied
The INT conversion circuit 6b performs scanning line conversion by deleting even-numbered line signals among the 525 scanning line signals in a certain frame, and deleting odd-numbered line signals in the next consecutive frame. . Therefore, in this case, the motion component is preserved between two consecutive frames.

The output of the NINT/INT conversion processing circuit 6b is supplied to the switching circuit 8b after being subjected to predetermined moving image processing by the moving image processing circuit 7b. This switching circuit 8b is NINT/
Either the output of the INT conversion circuit 5b or the output of the moving image processing circuit 7b is selected, and this control is performed by the motion aliasing detection circuit 9b. The motion aliasing detection circuit 9b controls the switching circuit 8b so that the output of the video processing circuit 7b is selected when the output signal of the NINT/INT conversion circuit 6b has an aliasing component due to motion, and there is no aliasing component. At this time, the switching circuit 8b is controlled so that the output of the NINT/INT processing circuit 5b is selected.

Note that details of the moving image processing circuit 7b and the motion aliasing detection circuit 9b will be described later.

Among the 0 to 8 MHz components output from the two-dimensional LPF 2b, the 0 to 4 MHz components are extracted by subtracting the input and output of the horizontal HPF 3b by the subtraction circuit 10b, and are interlaced by the NINT/INT conversion circuit 11b. converted into a signal. This conversion process is the same as the conversion process of the N I NT/I NT conversion circuit 6b described above.

The output of the NINT/INT conversion circuit 11b and the output of the switching circuit 8b are added by an adding circuit 12b.

The reason for using such adaptive operation is as follows.

Regarding motion, since the same signal is transmitted by field repetition, two consecutive fields within one frame (1/30 second) can be treated as a still image. but,
In such a method, movement becomes a deterioration factor. This will be explained with reference to FIG. The figure shows a rectangular pattern moving horizontally (from left to right) at a constant speed. FIG. 11(a) shows the original signal, in which smooth movement is expressed from field n to field n+3. FIG. 11(b) shows the case of field repetition described above. According to FIG. 11(b), it can be seen that the edge part swings left and right with respect to the center of gravity of the movement. Such discontinuity in display with respect to continuity of movement is visually recognized as jerky and unnatural movement called motion jerkiness. For example, it is also reported in Makoto Miyahara, "Relationship between visual characteristics and image quality for moving images and its application to TV signal band compression, J. NHK Technical Research, 1970, Vol. 27, No. 4, pp. 141-171 As described above, the above-mentioned field repetition has a narrow range of permissible visual characteristics in terms of smoothness of movement.

Therefore, in this embodiment, when the width of movement between two fields becomes large, as shown in FIG. 12(a), the luminance signal Y is Delete. That is, in the motion area, locally field thinning transmission is performed. Therefore, the movement area is a factor of 307 flicker, but the area shown by the broken line in Fig. 12(a) is the so-called uncovered background, which is the part left after movement, and is not very useful in terms of image quality. There is almost no visual deterioration as it is not a visible part. As shown in FIG. 12(b), on the receiving side, reproduction can be performed using a field in which the luminance signal Y is deleted and only the additional signal is superimposed.

Now, returning to FIG. 1, a transmission device according to an embodiment will be described.

FIG. 1 is a circuit diagram showing an example of a specific configuration of the band compression circuit 23, level conversion circuit 24, and side information encoder 25 shown in FIG. In addition, in FIG. 1, the band compression circuit 2
3 and the side information encoder 25 are mixed together, so for convenience of explanation, the level conversion circuit 24 is shown on the side closest to the human power side, but in principle it can be inserted anywhere in the signal processing path shown in FIG. It is something.

In FIG. 1, a frame thinning circuit 5g is a feature of the present invention.

As shown in Figure 6 above, if a signal is transmitted using the area set out for side information (the area marked with diagonal lines in the figure), the permissible amount of information per 1/30 second is: The amount of information is 525/4 vertically [c, p, h] x horizontal 1 [MHzl].

The circuit shown in FIG. 1 converts an input signal with a frame frequency of 60 Hz into a signal every 1/30 seconds using a frame thinning circuit 5g.

Because frames are thinned out on the sending side in this way,
On the receiving side, reproduction is performed using frame interpolation. In this case, to reduce the unnaturalness of the movement,
The sum of the input signal and the output signal of the frame delay circuit 1g is taken by the adder circuit 2g, and this is halved by the 1/2 coefficient circuit 3g.
Multiply this to obtain the average output of the signal for two frames. 2D L
PF4g limits the side signal to the spectrum characteristics shown in FIG. 13(a). During transmission, 1/2 information is processed by the line thinning circuits 13d and 20d for interlace conversion, so the amount of information is equal to 525/4 [c, p, h] xi [M7]. The signal obtained in this manner is supplied to a field thinning circuit 5g, where information is thinned out for each frame, resulting in a frame frequency of 30 Hz.

The vertical LPF 6g extracts a signal having the spectrum shown in FIG. 13(b) from the signal having the spectrum shown in FIG. 13(a) output from the frame thinning circuit 5g. The adder circuit 7g subtracts its output signal from the input signal of the vertical LPF 6g. By passing this subtracted output through the horizontal LPF 8g, a signal having the spectrum shown in FIG. 13(C) can be obtained. The vertical frequency shifter 9g performs 4-line inversion processing on this signal in the vertical direction, thereby inverting the first signal.
A signal with the spectrum shown in Figure 3(d) is obtained.

The line thinning circuit 10g performs line thinning processing on the output signal of the vertical frequency shifter 9g to obtain a signal with the number of scanning lines being 262.5 and one horizontal period being time expanded to 64 μs. The frame frequency of this signal is 3
0Flz, the band is 0-0.5MHz. The line distribution circuit 11g divides the input signal and obtains two signals each having 131 scanning lines. Time compression/time division multiplexing circuit 12g
obtains a signal having the number of scanning lines of 131 x 2 in one horizontal period by time-compressing the two signals output from the line distribution circuit 11g to 1/2 and time-division multiplexing the compressed output. . As a result, the number of scanning lines is 131,
A signal with a frame frequency of 30H21 and a band of 0 to IMHz can be obtained.

The line interpolation filter 13g converts the signal with 131 scanning lines output from the time compression/time division multiplexing circuit 14g into a signal with 525 scanning lines.

At this time, the signal peak value becomes 1/4 and is distributed over 525 scanning lines. This signal is transmitted every 1/30 seconds, 1/6
Since the output is only for 0 seconds, the line distribution circuit 14
Distribute to odd and even lines using g. Then, after the signal of one line is delayed by one field by the field delay circuit 15g, both signals are selectively selected by the switch circuit 16g according to the field switching signal, so that the number of scanning lines is 262. 5. Obtain a signal with a field frequency of 60 Hz and a band O to IM)'Iz.

The output of the vertical LPF 6g is further supplied to a line thinning circuit 17g. This line thinning circuit 17g thins out the number of scanning lines of the input signal to 131, and doubles the time. As a result, the number of scanning lines is 131 and the frame frequency is 30Hz.

Signals in the band 0 to IMHz can be obtained. This signal is converted to 525 scanning lines by a line interpolation filter 18g, and its peak value is reduced to 1/4. Therefore, no total signal energy is converted. Thereafter, this signal is transmitted to the scanning line number 2 by a line distribution circuit 19g, a field delay circuit 20g, and a switch circuit 21g.
62.5 lines, field frequency 60Hz, band 0 to IM
This becomes the Ttz signal.

The outputs of the switch circuits 16g and 21g are sent to the multiplier circuit 22g.
, 23g. The frequency of this subcarrier for orthogonal modulation is (6/7) fs c =195 f.

-3,07M1(z However, fH: is set to the horizontal synchronization frequency, and the phase is inverted for each field. This phase inversion is performed by the phase shift circuit 24g and the switch circuit 25g.

Note that 26g is a phase shift circuit for giving a phase difference of π/2 to the subcarriers supplied to the multiplication circuits 22g and 23g.

The outputs of the multiplier circuits 22g and 23g are supplied to an adder circuit 27g, where the in-phase and quadrature modulation components are summed. A horizontal band pass filter (hereinafter, a band pass filter will be referred to as BPF) removes unnecessary components other than 2 to 4 MHz from this addition output. As a result, a multiplexed signal having a spectrum indicated by diagonal lines in FIG. 4 is obtained. Note that the multiplication circuit 25d
.

The signal input to 26d is a signal having a spectrum shown in a solid line frame in FIG.

Next, the receiving device shown in FIG. 2 will be explained, but first, the receiving device shown in FIG.
A receiving system to which the present invention is applied will be explained using the drawings and FIG. 16.

FIG. 15 shows processing blocks on the receiving side.

In FIG. 20, 41 is an input terminal to which a received signal is supplied. The received signal supplied to this input terminal 41 is decoded by an NTSC decoder 42 into a luminance signal Y and chromaticity signals I and Q. In this embodiment, since all the additional signals are included in the luminance region, the luminance signal output of the NTSC decoder 42 includes the additional signals. Therefore, the luminance signal output of the NTSC decoder 42 is Y
The signal is supplied to both the H decoder 43 and the side information decoder 44, and is decoded. However, in FIG. 15, in order to simplify the explanation, the NTSC decoder 42, Y
, decoder 43, and side information decoder 44 are shown separately, and although the center signal is processed while containing the additional signal, some interference remains in the additional signal. Therefore, as an actual television receiver, NTSC
The signal separation circuits of decoder 42, Y, decoder 43, and side information decoder 44 operate as one, and each decoder 4
2, 43, and 44 so that unnecessary signals are not input.

The brightness high frequency signal YH of 4 to 5 MHz decoded by the decoder 43 is added to the brightness low frequency signal YL of the center signal in an adder circuit 45. As a result, a luminance signal Y having a band of 0 to 5 MHz is obtained.

This luminance signal Y is time-compressed by a factor of 415 in the time compression circuit 46, so that it has a band of 0 to 6.25 MHz.

This time compressed signal is processed by a non-interlaced conversion circuit 47 with a number of scanning lines of 525, a frame frequency of 60 Hz, and a band of O~
It is converted to a signal of 13MFLz.

On the other hand, the side signal decoded by the side information decoder 44 is time-compressed by a factor of 1/4 by the time compression circuit 48. As a result, the number of scanning lines is 525 and the frame frequency is 60 H.
A signal with a z% band of 0 to 8 MHz is obtained.

This time-compressed side signal and the center signal output from the increment conversion circuit 47 are combined by a screen synthesis circuit 49 and converted into a signal having a large aspect ratio of 16:9. Luminance signal Y1 color difference signal 1. Q is R, G by the inverse matrix circuit 50.

The signal is converted into a B primary color signal and used for display.

FIG. 16 shows an example of a specific configuration of the side information decoder 44.

In the figure, an additional signal multiplexed composite signal output from an NTSC decoder 42 is supplied to the Y/C separation circuit 11. This Y/C separation circuit 11 separates the input signal into a luminance signal Y and a chromaticity signal C. Of these, the luminance signal Y is supplied to the additional signal extraction filter 21. This additional signal extraction filter 21 extracts an additional signal included in the input luminance signal Y from the input luminance signal Y. The extracted additional signal is supplied to the orthogonal synchronous demodulation circuit 31 and reproduced into a baseband signal using a subcarrier having a frequency of 6/7fSC (subcarrier frequency). This demodulated output is converted into a television signal as an additional signal by a band compression decoding circuit 41.

Note that the subcarrier for demodulation is generated by the subcarrier recovery circuit 51 according to the additional signal multiplex decoded signal.

Now, returning to FIG. 2, a receiving device according to an embodiment will be described.

In FIG. 2, the horizontal HPF 1j extracts components of 2 to 4 MFIz from the input signal of the side information decoder 44.

It is now assumed that the signal being input to the horizontal HPF 1j is an n+1 field signal. n, n+1 within one frame
In a signal with 525 scanning lines made from two consecutive fields of signals, the information on adjacent scanning lines is originally (525/8) [c, p, h
] are expressed by 525 scanning lines, so they have a very high correlation and can be regarded as almost identical signals.

As shown in FIG. 12(b), in the motion area, n
, n+1 fields, only an additional signal whose phase is inverted for each field is multiplexed into one field, and the luminance signal is deleted. On the other hand, in the still image area, in addition to the additional signal that is inverted for each field, there is a luminance signal Y representing the same image.

The output signal of HPFlj is sent to field delay circuit 2j, line delay circuits 3j and 4j, and addition circuit 5no.

6j, 1/2 coefficient circuits 7j, and 8j are supplied to upper and lower line averaging circuits. From this upper and lower line average circuit,
In one field of the moving image area, only the additional signal appears, and in the other field, the additional signal with the luminance signal Y superimposed thereon appears. Further, when the inter-field inversion average is obtained by the addition circuit 9j and the 1/2 coefficient circuit 10j, in the case of a still image,
The luminance signal Y is canceled and only the additional signal is obtained. On the other hand, in the case of a moving image, the luminance signal Y is not canceled out.

Therefore, by selecting the minimum output from the three outputs of the average output of the upper and lower two lines in each field of n and n+1, and the field inversion average output, it is possible to obtain a signal that does not include the luminance signal and consists only of the additional signal. can.

That is, the additional signals included in the three modes of average of the upper and lower two lines in each field of n and n+1 and field inversion average output are all the same, and the luminance signal Y is excluded in at least one mode depending on the image content. There is.

This algorithm is determined by the minimum determination circuit 13j. In this case, the signals of the above three modes are transmitted to the absolute value circuit 1.
After the absolute value of the amplitude is taken at step 1j and single pulse noise is removed at median filter 12j, it is supplied to minimum judgment circuit 13j and subjected to minimum judgment. Note that the minimum determination circuit 13 is configured to determine the still image mode if there are two or more modes that take the same minimum value.

The above is an algorithm for determining the three modes, and this algorithm is 1f! Because it makes the first determination, it is characterized by fewer malfunctions due to transmission noise, etc.

In order to separate the additional signal and the luminance signal Y, 525 scanning line signals are required. In the still image mode, this signal may be generated from the signals of the n and n+l fields. Therefore, in the still image mode, the switch circuit 14j
, 15j select the signals of fields n and n+1, respectively.

In the n+1 field processing, the above-mentioned addition circuit 6j and 1/2 coefficient circuit 8j are processed from 262.5 scanning line signals.
The average of the upper and lower lines is taken, and the inverting circuit 16j inverts the average to generate 262.5 scanning line signals. This signal is selected by the switch circuit 15j, and the original 262.5 scanning line signals are selected by the switching circuit 14j, resulting in a total of 525 scanning line signals. Similarly, in the n-field processing, the above-mentioned addition circuit 5j11
The average of the upper and lower lines is taken by the /2 coefficient circuit 7j, and the phase of this is inverted by the inverting circuit 16j, and the original scanning line signal is sent to the switch circuit 14j.

Select with 15j.

The connection states of switch circuits 14j and 15j are controlled by the output of minimum value determination circuit 13j. A valid signal is only for one field period of one frame (two fields, 1/30 seconds). Therefore, this valid signal appears at 1/
Switch circuit 17j, 1 only for 60 seconds, 1 field period
8j is turned on and this valid signal is supplied to the vertical HPF 19j.

This vertical HPF 19j is (525/2) ± (525/
8) [Has a passband of c, p, hl and extracts the additional signal from the input signal. The extracted additional signal is sent to the multiplication circuit 2
Orthogonal demodulation is performed at 0j and 21j. The horizontal LPF 22j extracts O to IMHz components from this demodulated output. As a result, a signal with a number of scanning lines of 262.5 and a frame frequency of 307 is obtained. This signal is converted into a signal having 131 scanning lines by a line thinning circuit 23j. horizontal LP
The vertical spectrum of the signal output from F22 j is 5
Since it is limited to the 25/8 [c, p, and hl bands, information is preserved even if it is converted to a signal with 131 scanning lines by line thinning.

The signal shown in FIG. 13(d) is transmitted by time-division multiplexing two signals with 131 scanning lines, so the original number of 131 scanning lines is transferred to the time division circuit 24j1 and the time expansion circuit 25j. After returning to the two signals, the line superimposing circuit 26j converts it into a signal with 262.5 scanning lines. The spectrum of this signal is shown in FIG. 13(d).

After that, this signal is processed by the line interpolation circuit 27j to convert the number of scanning lines to 5.
Convert to 25 signals. Next, when this signal is shifted by (525/8) [c, p, hl] by the vertical frequency shifter 28j, a signal having the spectrum shown in FIG. 13(c) is obtained.

On the other hand, the signal on the multiplication circuit 21j side has 131 scanning lines and has a spectrum as shown in FIG. 13(b). This signal is processed by the line interpolation circuit 29j, and the number of scanning lines is 5.
After being converted into 25 signals, they are added to the output of the vertical frequency shifter 28j in an adder circuit 30j. As a result, the adder circuit 30j outputs a signal having the spectrum shown in FIG. 13(a). However, this signal is 1/30
Since the signal appears once every second, the frame delay circuits 31j and 32j have a delay amount of 1/60 second.

An adder circuit 33j and a 1/2 coefficient circuit 33 generate a frame interpolation signal, and a switch circuit 35j selectively selects this signal and the output of the frame delay circuit 31j every 1/60 seconds,
A signal with 525 scanning lines and a frame frequency of 60 Hz is obtained.

By the way, as shown in FIG. 17, the frame interpolation signal is simply an average of the signals of the previous and subsequent frames, and therefore has an element that causes unnatural motion. Therefore, the motion detection circuit 36j detects the amount of motion of the image, and uses the detection output to control the high frequency component of the frame interpolation signal. That is, when there is movement, the unnaturalness of the movement is eliminated by suppressing the high frequency components of the frame interpolation signal.

Note that the high-frequency component of the field interpolation signal output from the 1/2 coefficient circuit 34 is processed by the horizontal LPF 37j to which this frame interpolation signal is supplied and the addition circuit 38j that performs subtraction processing on the input/output signals of the horizontal LPF 37j. taken out. The amplitude of this high frequency component is controlled by the multiplication circuit 39j according to the motion detection output. This control output is applied to the horizontal LPF 37 j in the adder circuit 40j.
It is added to the low-frequency component output from.

The output of the switch circuit 35j is a level conversion circuit 41 having characteristics opposite to those of the level conversion circuit 24 on the transmitting side shown in FIG.
It is converted to the original signal at j. This signal is sent to color decoder 4
2j, luminance signal Y, chromaticity signal 1. It is decoded by Q.

According to this embodiment described in detail above, the following effects are achieved.

(1) Interference of side signals with respect to center signals can be minimized.

This is because when transmitting the side signal, the amount of information is reduced by the frame thinning circuit 5g of FIG. 1 before transmission.

(2) Deterioration of the quality of side signals can be prevented.

This means that information lost due to frame thinning is transferred to frame delay circuits 31j, 32j, adder circuits 33j, 1/
This is because the reproduction is performed using the two-coefficient four-way 34j. This makes it possible to prevent large-area flicker from occurring and eliminate deterioration of still images. However, in the case of videos,
The interpolation frame particularly impairs the unnaturalness of the movement at the edges. However, this also includes the motion detection circuit 36j1 horizontal LPF 37j, addition circuits 38j and 40j, and multiplication circuit 3.
If 9j is used and there is a large movement, there is no problem because the high-frequency components of the interpolated signal are attenuated. Moreover, since the screen side portion F2 is often out of the gaze point of the entire screen and has a high tolerance for deterioration of image quality, the deterioration of visual characteristics is smaller than the deterioration of physical characteristics. This also allows some deterioration of the side signal to be tolerated.

Although one embodiment of the present invention has been described above in detail, it goes without saying that the present invention is not limited to this embodiment.

[Effects of the Invention] As described above, according to the present invention, it is possible to realize a system that can transmit and receive an additional signal for wide-aspect conversion without causing deterioration of the original NTSC signal or itself.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing the configuration of an embodiment of a transmission device according to the present invention, FIG. 2 is a circuit diagram showing the configuration of an embodiment of a receiving device, and FIG. 3 is a transmission diagram to which the present invention is applied. A circuit diagram showing the configuration of the system, FIGS. 4 to 7 are diagrams for explaining the operation of FIG. 3, and FIG. 8 shows an example of a specific configuration of the motion adaptive blurring processing circuit shown in FIG. 3. The circuit diagram shown in Figure 9 is
FIG. 10 is a circuit diagram showing an example of a specific configuration of the still image processing circuit shown in FIG.
The figures are diagrams for explaining the operation in Figure 8, Figures 13 and 14 are diagrams for explaining the operation in Figure 15,
16 is a circuit diagram showing an example of a specific configuration of the side information decoder shown in FIG. 15, FIG. 17 is a diagram for explaining the operation of FIG. 2, 1st
FIG. 8 and FIG. 19 are diagrams for explaining different examples of conventional transmission systems, respectively. 1g...Frame delay circuit, 2g, 7g, 27g...
・Addition circuit, 3g...1/2 coefficient circuit, 4g...2
Dimensional LPF, 5g...Frame thinning circuit, 6g...
・Vertical LPF, 8g...Horizontal LPF, 9g...Vertical frequency shifter, 10g, 17g...Line thinning circuit, 11g...Line distribution circuit, 12g...1/2 time/compression multiplex circuit, 13g, 18g...Line interpolation circuit, 14g, 19g...Line distribution circuit, 15g. 20g...Field delay circuit, 16g, 21g. 25g...Switch circuit, 22g, 23g...Multiplication circuit, 24g, 26g...Phase shift circuit, 28g...Horizontal BPF, lj...Horizontal HPF, 2j...Field delay circuit, 3j, 4j... line delay circuit, 5j. 6j, 9j, 30j, 33j, 38j, 40j...addition circuit, 7j, 8j, 10j, 34j...1/2 coefficient circuit, llj...absolute value circuit, 12j...median filter, 13j... - Minimum value judgment circuit, 14j. 15j, 17j, 18j, 35j... switch circuit,
16j...Inversion circuit, 19j...Vertical HPF, 20
j, 21j, 39j, . . . multiplication circuit, 22j. 37j...Horizontal LPF, 23j...Line thinning circuit, 24j...Time division circuit, 25j...Time expansion circuit, 26j...Line superimposition circuit, 27j, 29j...
...Line interpolation circuit, 28j...Frequency shift circuit,
31j. 32j...Frame delay circuit, 36j...Motion detection circuit, 41j...Level conversion circuit, 42j...Color decoder. Applicant's representative Patent attorney Takehiko Suzue Figure 4 Figure 5 Heat 44 μs - Figure 7 Figure 9 - Figure 10 (c) (d) @ Figure 13 (a) (b) Figure 14 Pooled signal after field resistant signal Figure 17 - PIF) 7-

Claims (2)

[Claims] (1) A non-interlaced signal with an aspect ratio of 16:9 or 5:3, a number of scanning lines of 525, and a frame frequency of 60 Hz, a main signal that displays the center part of the screen with an aspect ratio of 4:3, and the above screen center. In a split television signal transmission device that divides and transmits additional signals that display the side part of the screen excluding the side part of the screen, when transmitting the additional signal, this signal is thinned out by one frame every two frames, by frame thinning, A divided television signal transmission device characterized in that it is configured to convert into a non-interlaced signal with a number of scanning lines of 525 and a frame frequency of 30 Hz for transmission. (2) It is divided into a main signal that displays the center part of the screen with an aspect ratio of 4:3 and an additional signal that displays the side part of the screen excluding the center part of the screen, and this additional signal is transmitted once every two frames. By frame thinning, a non-interlaced signal with an aspect ratio of 16:9 or 5:3, 525 scanning lines and a frame frequency of 60 Hz is converted into a non-interlaced signal with a frame frequency of 30 MHz, and the aspect ratio is is 16:9 or 5
: A split television signal receiving device that reproduces the screen of 3, using the received additional signal, interpolation means for reproducing the signal of the frame thinned out by the frame thinning, and using the received additional signal. The present invention is configured to include a motion detection means for detecting a motion of an image, and a control means for controlling the amount of attenuation of the high spatial frequency component of the output of the interpolation means according to the detection output of the motion detection means. A divided television signal receiving device characterized by: