JPS63232587A - Image transmitter for tv signal - Google Patents

Abstract

PURPOSE:To maintain excellent picture qualities against both still and moving pictures, by changing parameters for signal processing in accordance with the movement of picture in the course of signal processing in a time-vertical frequency area. CONSTITUTION:Signals YF, from which components which become folded distortion are removed, are produced from luminance signal Y by means of a time- space filter 1. The signals YF produces signals of (1-k)Y0+kYF at a mixing circuit 10 together with signals Y0 which are produced by correcting the delayed amount of the filter 1 at a delay circuit 1. The (k) is a numerical value which is determined in the range of 0-1 in corresponding to the detecting level of a level discriminating circuit 8 when a component which becomes folded distortion is detected at a folded component detecting circuit 6. Namely, only when the component which becomes folded distortion exists, this constitution uses the signal of the time-space filter 1 and deterioration of picture quality, such unclear pictures, etc., is eliminated at the time of moving pictures.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an image transmission device for television signals, and more particularly to an image transmission device suitable for generating high-definition television signals compatible with current televisions. .

[Conventional technology]

Various methods are being researched and developed to achieve high image quality and high definition for television. this house.

There is a method described in Japanese Patent Application Laid-Open No. 171387/1983 as a method that is compatible with current televisions and also achieves high definition. In this method, the resolution is improved by more than 1.5 times with the same frequency bandwidth as the current NTSC television signal by multiplexing the high-band luminance signal at a location conjugate with the color subcarrier in the time-vertical frequency domain. Achieve high definition. In addition, by performing signal processing in the 1-hour vertical frequency domain, various interferences occurring in current NTSG television signals, such as crosstalk between luminance signals and chrominance signals, and aliasing distortion that occurs due to scanning, can be eliminated. This reduces interlacing interference and other problems that may occur, resulting in higher image quality.

[Problem that the invention seeks to solve]

Since the high-definition television system having the above-mentioned compatibility involves signal processing in the 1-hour vertical frequency domain, there are problems such as deterioration of image quality in the case of moving images depending on the signal processing.

An object of the present invention is to maintain good image quality for both still images and moving images. An object of the present invention is to provide an image transmission device for high-definition television signals having the above-mentioned compatibility.

[Means for solving problems]

The above object is achieved by performing so-called motion adaptive processing in which parameters for signal processing are changed in accordance with the movement of an image in signal processing in the time-vertical frequency domain.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows a block configuration of an embodiment of a television signal transmission device according to the present invention.

This is because the area surrounded by a dotted line in the figure can be realized with a configuration similar to that of a commonly used image carrier system.

Explanation will be omitted.

On the other hand, the area surrounded by a solid line is the configuration of the main signal processing section of the present invention. The number of scanning lines obtained from the imaging system is 525,
The 60-frame, sequentially scanned 3 color signals, R, G, and B, are sampled by an A/D converter at a sampling frequency of 1, for example, 8 fsc (fsc: color subcarrier). In addition, R, G, B
Here, the signal is assumed to have already been subjected to γ correction. This sampled signal is processed by digital clamping to set the blanking level to a specific value, and then by matrix calculation to remove aliasing distortion components associated with interlaced scanning. Components that cause aliasing distortion in the scanning signal are removed by a spatiotemporal filter, and then the scanning lines are thinned out to convert into an interlaced scanning signal similar to the current one.

Furthermore, components that cause crosstalk from the luminance signal to the chrominance signal are removed, and at the same time, the constant luminance theorem is satisfied.

For example, γ compensation is performed for a luminance signal of 1.5 MHz or higher.

Next, the luminance signal high-frequency component YH (component of 4.2 MHz or more) is used as high-definition information YH', and L-near multiplexed where it is conjugate with the color subcarrier in the time-vertical frequency domain, resulting in a burst signal and a synchronization signal. etc., and a D/A converter generates a Yon signal for a high-definition television having 1 compatibility.

The control signal generator generates various control signals synchronized with, for example, the black burst signal of the current NTSC signal.

Below, the configuration and operation of each of the above blocks will be explained in detail using examples. Note that the A/D conversion section and the D/A conversion section are commonly used and can be easily implemented, so their explanation will be omitted.

First, an embodiment of the digital clamp section is shown in FIG. 2. This embodiment is for three primary color signals quantized with, for example, 8 bits.

A case is shown in which the horizontal blanking period is set to a specific value of 64/256.

The latch circuit 1 has a horizontal blanking cycle clock CK.
Then, the blanking period value X is latched. The level signal generator 2 generates a 64-x signal for X, and the adder circuit 3 adds the input signal and 64-x. Through this operation, the level is always maintained during the horizontal blanking period The input signal can be clamped to a constant value of 64/256. Note that the level signal generator 2 can be easily realized using, for example, a ROM. Note that in consideration of the influence of noise and the like, it is preferable to use the average between a plurality of adjacent pixels as X.

Next, an embodiment of the YIQ conversion section is shown in FIG.

By matrix calculation, the three primary color signals R2G, B
Therefore, the luminance signal Y2 color signals I and Q are Y=0.3R+0
．． 59G+0.11BI=0.6OR-0,28G-0
, 32BQ=0.21R-0,52G+0.31.8. For example, the coefficient calculation circuit 4 calculates 0.3R, 0.6R, respectively, for the R signal.

0.21H calculation is performed for the G signal.
For the 59G, -0,28G, -0,520, and B signals, calculations of 0.11 B, -0,32B, and 0.31 B are performed. By adding these in the adder circuit 3, the desired result is obtained. Convert to Y, I, Q signals.

Note that these coefficient calculation circuits can be easily realized using a ROM or the like.

Next, an example of removing aliasing distortion caused by interlaced scanning will be described. For ease of understanding, the principle will first be explained with reference to FIG. 4.

In the imaging system, television signals are read out by scanning, but what is the process of this scanning?

As shown in FIG. 4, one hour corresponds to a kind of sampling in the vertical area. Therefore, the number of scanning Altk is 525,
In 60-frame sequential scanning, the temporal frequency f.

In the time-vertical frequency domain of vertical frequency Y, f=6
Sampling frequency f with 0Hz, v=525 as the fundamental frequency
A signal spectrum exists around tm. On the other hand, in interlaced scanning with 525 scanning lines and 30 frames,
A signal spectrum exists around the sampling frequency with f=30Hz and v=525/2 as the fundamental frequency. In order to avoid aliasing distortion, it is necessary that the spectra do not overlap with each other.

Therefore, as shown in FIG. 4, there are 525 pieces.

The sequential scanning signal of 60 frames is band-limited in the time-vertical frequency domain to the rectangular area with a black frame using a spatiotemporal filter, and then the scanning lines are thinned out one by one using a 2:1 subsampling method. By converting the signal into an interlaced scanning signal, it becomes possible to remove aliasing distortion in interlaced scanning.

Signal YF from which components causing aliasing distortion have been removed by router 1
Create. Then, the mix circuit 10 uses (
1-k) Create a Yo+kYF signal. However, when the aliasing component detection circuit 6 detects a component that causes aliasing distortion.

In the level determination circuit 8, O~
It is a numerical value determined within the range of 1. In addition.

The reason why the signal Yp of the spatio-temporal filter 1 is not always used is as follows.
As will be explained later, in a spatio-temporal filter, calculations are performed between scanning lines spanning multiple frames, so for moving images that do not originally have aliasing distortion, blurring may occur as a result of this calculation. This is to prevent That is, in the present invention, the signal of the temporal and spatial filter 1 is used only when there is a component that causes aliasing distortion, and image quality deterioration such as image blurring during moving images is removed. .

In addition, the time frequency component detection circuit 7 has a time frequency that cannot be detected with interlaced scanning signals! = 30
The Hz component is also detected as motion information MDI, and this information is used in a high-definition information multiplexing section, which will be described later, to perform signal processing that enables motion detection on the receiving side.

After performing the above signal processing, the scanning line thinning & time axis expansion circuit 11 thins out each scanning line and converts the time axis into two.
Expand it twice to make it an interlaced scanning signal.

Next, each block will be explained using examples.

First, an example of the spatio-temporal filter 1 is shown in FIG.

Here, fm=30. ν1=525/2”.

FIG. 5A shows information on the scanning line used in the filter configuration with respect to the scanning line Yo, where Yl.

Y-t corresponds to a scanning line that is advanced or delayed by i number of scanning lines with respect to YO, respectively.

On the other hand, FIG. 6B shows a block configuration. 2H delay circuit 14. The signals delayed by 2 scan lines, 1 scan line, and 52 degrees by the IH extension circuit 15 and the 520HW extension circuit 16, respectively, are multiplied by a predetermined coefficient in the coefficient multiplication circuit 17, and the results of these calculations are multiplied by the adder circuit 3. By adding them, the output signal YF of the spatio-temporal filter 1 is obtained. Note that the nH delay circuit is RAM
It can be easily configured. Further, the coefficient multiplication circuit can be easily realized by table lookup using ROM.

Figure (c) shows the spatiotemporal filter 1 used in this example.
shows the time-vertical frequency domain characteristics of

This concludes the explanation of the first time-spatial filter 1, and an example of first-order aliased component detection and first time frequency acid content detection will be described with reference to FIG.

In the same figure, (a) shows the block configuration, and (b) shows the folded component AIS.
(C) shows the detection value range of motion information MDI.

The scanning line signals of Yδ281 Yo and Y-sza, which are part of the output signals of the nH delay circuit shown in FIG. Add the results. By this calculation, the output signal A of the adder circuit 3 has a transfer function of sinπf/f, +5
The characteristic in the 11 time-vertical frequency domain corresponding to the output signal of the irtc f/2 f- filter is shown in FIG. 3(c).

The output signal A is further transmitted to the IH delay circuit 15, 2H delay circuit 14. Coefficient multiplication circuit 17. This calculation is made up of adder circuit 3.

The signal AIS finally obtained is shown in the same figure (
The characteristic is as shown in b), and the region of the passband indicated by diagonal lines is detected as a component resulting in aliasing distortion.

Using this AIS signal, the level determination circuit 8 generates a coefficient k depending on the presence or absence of the signal level.

The other output signal A is similarly generated in the level judgment circuit 8 according to the signal level, is subjected to delay adjustment in the delay circuit 2, and is used as motion information MDI in the high-definition information multiplexing section described later. .

This completes the explanation of the aliasing component detection, and next, one embodiment of the level determination circuit will be explained with reference to FIG.

The absolute value quantization circuit 18 generates an absolute value quantized output signal with characteristics as shown in FIG.

This circuit can be easily realized using a ROM or the like. This output signal is smoothed horizontally, vertically, or temporally by a spatial smoothing circuit 19.Here, an example is shown in which smoothing is performed over five horizontally adjacent pixels, that is, one pixel. aQ, al to the pixel delayed by the delay circuit 20
, al are multiplied by the coefficients, and the adder circuit 3 adds them to perform smoothing.
With the characteristics shown in FIG. 10, the numerical values of the coefficients are determined in accordance with the input signal.

To avoid malfunctions caused by noise, etc.

Although it is desirable to have a spatial smoothing circuit, it may not be necessary in some cases.

This concludes the explanation of the level judgment circuit, and now on.

Let us now explain the spatio-temporal filter 2. To make it easier to understand, first of all, the time of compatible high-definition television signals -
The signal spectrum in the vertical two-dimensional frequency domain will be explained with reference to FIG.

In the time-vertical frequency domain, one color subcarrier fsc is located, and the spectrum of the color signal C exists around these. On the other hand, it is located in the sub-□ which is used for multiplexing high-definition information, and a spectrum of high-definition information Y, / exists around these. Then, color signal C1 and high-definition information YH'
In order to avoid crosstalk between the two color signals, the first color signal C is sent to the second color signal C. The fourth quadrant, YH', must fall within the 1st and 3rd quadrants. Therefore, it is necessary to perform band limitation in the vertical direction for both color signals and high-definition information. This function is realized by the spatio-temporal filter 2.

FIG. 12 shows an embodiment of the spatio-temporal filter 2.

The signal delayed by the IH delay circuit 15 is 1/4.1/2.
By multiplying the coefficients of 1/4 and adding these in the adder circuit 3, the transfer function performs vertical band limitation with the characteristic of ν cos"π□. Then, the spatiotemporal filter 1 The delay circuit 22 adjusts the difference in the amount of delay between
(kn = O when stationary) to reduce multiplexed signal components in a moving image and reduce crosstalk components with the luminance signal Y.

Finally, an example of scanning line thinning and time axis expansion will be explained in the 13th section.
This will be explained with a diagram. The sequential scanning signal passes through the latch circuit 1 and is sent to the IH memory circuit 23 by 2 lines (6 lines in time).
1.5μ5ec) '77 Incorporated.

The WT address necessary for writing is generated by the WT address generation circuit 24. On the other hand, reading from IH memory is performed at half the writing speed, and data for exactly one line is read in a period of 61.5 μsec.
The RD address necessary for this read operation is generated by the RD address generation circuit 25. There are two systems of IH memory circuits.

As shown in the figure, when one memory circuit is in the write operation, the other memory circuit is in the read operation, and the switch 26 is used to send the signals of the two memory circuits by 61.5μ.
The signal is switched to 861C period and converted into a continuous interlaced scanning signal. Note that in sequential scanning, the clock frequency is 8 fsc as described above, so in the interlaced scanning signal, the time axis is expanded twice, so the clock frequency is 4 fsc.

This concludes the explanation of aliasing distortion removal, and next, crosstalk component removal will be explained.

FIG. 14 is a block diagram of an embodiment of crosstalk component removal. The luminance signal YL is passed through a crosstalk component detection filter 29,
Color signal C2 high-definition information YH' and crosstalk component SO
Detect T. Then, in the level determination circuit 8, a numerical value is determined for the coefficient corresponding to the level of the crosstalk component. (The value is 0 when there is no crosstalk component.) On the other hand, the first spatiotemporal filter 3 extracts a signal YLF that becomes crosstalk in the luminance signal. Then, signals YLD-kY+, r are generated from the signals Y+, o and YLF whose delay has been adjusted in Mitsu 28, and only when there is a crosstalk component.

This crosstalk component is removed. This can also reduce blur when watching videos.

On the other hand, for the color difference signals I and Q, the motion information M
Depending on DI, the switch 26 selects the signal of the time direction filter 81 and the signal whose delay has been adjusted by the delay circuit 32.

In this case, when the MDI signal is zero and corresponds to stationary state, the signal of the time direction filter is selected. Then, the vertical filter 33 removes vertical high frequency components.

Note that a configuration in which a mix circuit is provided in place of the switch 26 and switches continuously is also possible.

Further, the high-definition signal YH is adjusted to have a predetermined amount of delay in a delay circuit 30.

This concludes the explanation of the block configuration, and next, the configuration of each block will be explained based on an example.

FIG. 15 shows an example of the spatio-temporal filter 3, in which the transfer function Fa (f# q * μ) is given by. Here, μ indicates the horizontal frequency.

525H delay circuit 34, and -1/4.1/2. −
1/4 coefficient multiplication circuit 17. sin”π in adder circuit 3
Realizes the characteristic of f/f. Further, the IH delay circuit 35.
and coefficient multiplication circuit 17. With the combination of adder circuit 3
In"π□ is realized. Furthermore, the characteristic of sin"π□ is realized by the combination of 1 pixel delay circuit 20, coefficient multiplication circuit 17゜μ adder circuit 3. By connecting these three types of filters in cascade, a filter with the above transfer function Fs (f, shi, μ) is realized.

FIG. 16 shows an example of a crosstalk component detection filter,
By taking the difference between the signals YLO and YL of the 525H delay circuit 34 in FIG. 15, a filter of s10πf/f is constructed. Note that, as described later, this signal is the motion information MD.
II is used in the multiplex section of high-definition information. Furthermore, I
H delay circuit 35. Coefficient multiplication circuit 17. The combination of the adder circuits 3 realizes the characteristics of sin π/s. moreover,
1 pixel delay circuit 20. Coefficient multiplication circuit 17. Adder circuit 3
The characteristic of ginπμ/2fmc is realized. Therefore, in this crosstalk component detection filter, the transfer function Fs(f, shi, μ) is Fs(f, v, p)−sxnxf/fm·5intcv
/vx@ainxp/2fsc, and this output signal S
The c-block detects the shaded area as shown in FIG. 17 as a crosstalk component.

Further, FIGS. 18 and 19 show examples of a time direction filter and a vertical direction filter, respectively, and each has a characteristic characterized by the shaded area shown in the figure.

Incidentally, the level detection circuit is the same as that described above in FIGS. 8 to 10, and its explanation will be omitted here.

This concludes the explanation of crosstalk component removal, and next,
The compensating section will be explained, but for ease of understanding, the principle of this function will first be briefly described.

As is well known, in the current NTSC television signal, after applying gamma correction to the three primary color signals R, G, and B in the image transmitting section, a luminance signal and a color difference signal are created and transmitted. However, the color difference signal band is I signal 1.5 MHz, Q signal 0, 5 M
Hz, so components of 1.5 MHz or higher can only be sent as luminance signals, so 1.5 MHz
For the above components, the constant brightness theorem does not hold, and the brightness on the image receiving side decreases due to this. In luminance signal γ compensation, a luminance signal is first created from the three primary color signals without γ correction,
This luminance signal is γ-corrected at 1.5MHz.
The above luminance signal solves the problem of luminance reduction on the image receiving side.

FIG. 20 shows an example of luminance signal γ compensation in block configuration, including an N return signal Y and a high-definition signal Yl.

The color difference signals I and Q are sent to an RGB conversion circuit 36.

Three primary color signals R1 and Gl are generated by the following matrix calculation.

Convert the signal by Bz times.

R5=Y+0.96I+0.62Q In the γ conversion circuit 37, Rt t G i, t
Convert to a B x signal. The signal obtained by this processing is equivalent to a 3g color signal without γ correction.

Using this signal, the γ conversion circuit 38 converts 0.3Rz
A brightness signal Yγ is generated by calculating +0.59Gz +0.11BI. Then, in the Y1″ conversion circuit 39, γ
A corrected luminance signal (Yγ) 1/y signal is generated.

The output signal of this Y17y conversion circuit 39 is passed through the HPF 43 and becomes the high frequency component of the luminance signal Y, while the output signal of the multiplex circuit 42 is passed through the PF 44 and the output component is converted into the low frequency component of Y+. Perform luminance signal γ compensation.

Note that the γ' conversion circuit 40 has R1y/yiγlγi
By generating the γ/γj Ol ν81 signal, γ
Create a signal of the characteristics of turbidity. And YIQ conversion circuit 41
Then, Yy', I
A luminance signal and a color difference signal equivalent to those with changed γ characteristics such as Qt'*Qt' are generated.

Therefore, it is possible to change the γ characteristic through this process.

In addition, high-definition Yo is 4.2 MHz as described later.
In order to use the above components, the signal that has been γ compensated by the Y1″ conversion circuit 39 is used as is.

The configuration of each block will be explained below according to an embodiment.

FIG. 21 shows an embodiment of the RG/B conversion circuit.

For the color difference signals I and Q, each term of the matrix calculation is performed at the coefficient calculation port f14, that is, 0.96 I.

−0,27I, −1,II, and 0.62Q.

The calculations -0, 650, 1, and 7Q can be easily realized, for example, by table lookup using a ROM. Then, in the adder circuit 3, the three primary color signals R, G, and B are created by adding them to the luminance signal Y.

FIG. 22 shows an embodiment of a γ conversion circuit, a γ conversion circuit, and a Y1/γ conversion circuit, in which three [color signals R, G] are used.

For B, γ east circuit 48, 0.3R.

Signals of 0.59 G' and 0.11 B' are generated and added by an adder circuit 3 to generate a luminance signal Yγ.

The output signal 1/γ signal (Yγ) is obtained by the 1/y power circuit 49. Note that the γ east circuit and the 1/γ power circuit can be easily realized by table lookup using a ROM, for example.

FIG. 23 shows an embodiment of the γ' conversion circuit.

The γ/γ square circuit 50 converts γ/Y to the R, G, and B signals.
t γ/γ γ/γi generates R, G, and B signals. This can be easily achieved by table lookup using the same <ROM.

FIG. 24 shows an example of HPF, LPF.

The HPF is constructed by subtracting the output signal of the LPF 44 from the signal of the delay circuit 51 having the same amount of delay as the LPF 44.

In FIG. 25, the passband is one implementation μ fsc line region of the horizontal one-dimensional LPF. On the other hand, FIG. 26 shows an example in which the LPF is constructed in two dimensions, horizontal and vertical.

In the figure, the horizontal LPF circuit 52 is similar to the μ delay circuit 35. of FIG. Coefficient multiplication circuit 17. Adder @'Jllt
It consists of filters with characteristics of cos"π□ made up of 3.

In addition to the one-dimensional and quadratic characteristics shown above, the LPF used for luminance signal γ compensation may also have three-dimensional characteristics including the time direction.

This concludes the explanation of the luminance signal γ compensation, and next, the high-definition information multiplexing and processing circuit will be explained.

FIG. 27 shows the block configuration of this embodiment. The high-definition signal YH is 4
, 2 MHz or higher, and performs carrier suppression amplitude modulation in the modulator 54 using the subcarrier μ0 generated by the subcarrier generation circuit 55, L P F YH'
A circuit 56 extracts the lower sideband component to create high-definition information YH' whose frequency is shifted within the current ANTSC television signal band, as will be described later.

In addition, YL double signal, LPFYt, circuit 57
Luminance signal YL in the same 4 and 2 MHz band as the C signal
A delay circuit 61 adjusts the amount of delay.

On the other hand, the color difference signals I and Q are sent to a predetermined frequency of 1.5 MHz by an LPFI circuit 58 and an LPFQ circuit 59, respectively.

A signal in a band of 0.0 to 5 MHz is generated, and a quadrature modulation circuit 60 modulates it into a color signal C similar to the current NTSC, and a delay circuit 62 adjusts the amount of delay.

These YH', Yz6. The C signals are added in an adder circuit 3, and a synchronization burst μ0 addition circuit 65 inserts a synchronization signal, a burst signal, and a μ0 signal at predetermined positions to form a high-definition television signal. Furthermore, the aperture correction circuit 66 compensates for the gain reduction of high frequency components that occurs in the D/A converter.

Note that in high-definition television signals, the above-mentioned motion information M
A motion determination circuit 63 detects a motion that cannot be detected on the receiving side from DIO and MDII, and a motion information generating circuit 64 generates motion information that can be detected on the receiving side for such undetectable motion.

It is also possible to add.

Now, one of the Yt and *I*Q signals is connected to the RGB conversion circuit 36.
After converting it into a 3M color signal and performing delay adjustment in a delay circuit 67, a blanking signal of a constant level is added in a blanking addition circuit 68, and a high frequency component is compensated in an aperture correction circuit 66.

Hereinafter, the configuration of each block section will be explained in detail using examples.

FIG. 28 shows an example of the filters used here. Here, the filter is constructed of a 1-herans universal type filter having 15 taps. By changing the tap coefficients, various characteristics such as I, PF, and HPF can be realized. r, 1rI4 shows an example of the tap coefficients of each filter type.

FIG. 29 shows an example of frequency shift of a high-definition signal,
This is the case when the subcarrier μ0 is 0.6 fsc. 4, 2 of high-definition signals extracted by HPFYH circuit
~6.3 MHz components are subjected to carrier suppression amplitude modulation using a subcarrier of 0.6 fsc. By this operation, 2, 1~
4, lower sideband wave in 2 MHz band, 6.3-8.4 MHz
Upper sideband components occur in the z band. This is LPFYH
' A circuit extracts the lower sideband component and creates frequency-shifted high-definition information YH'.

FIG. 30 shows an embodiment of the high-definition signal amplitude modulation section. The input signal≠-data sequence Xl is given at a 4fsc cycle.
Based on the reference phase information of μ0 for every 4fac, 'I'0 # (ex e 'f'x P (Plg
In the zero multiplication circuit 70 which generates X every 20 cycles, the output signal Xo becomes X according to the input signal Xi and the phase information ψ5
Multiplication of o = Xt .cos3 i π/10 is performed, and this multiplication can be easily realized by table lookup using ROM.

Now, for the subcarrier μ0, as shown in FIG. 31(b), using the same phase point that falls in each field, @1 in the time-vertical frequency domain as shown in FIG. ．． High-definition information Yu' is placed in the third quadrant.

On the other hand, at 0.6fsc, as shown in WI(a),
The relationship is such that points with the same phase rise in each field. Then, in the second field, by inverting the phase of 0.6 fsc, a desired phase relationship of μ0 can be obtained. Therefore, in the polarity inversion control circuit 71, the second
This function of inverting the polarity of the field signal can also be easily realized using a ROM or the like.

FIG. 32 shows an example of orthogonal modulation of one color difference signal, I
, Q signal every 4 fsc period, the I and Q signals are alternately selected by the multiplex circuit 42, and the polarity is inverted as shown in the figure by the polarity inversion control circuit 71*I 1 t Q x y-Ii, -
Q4, IIS*... orthogonally modulated color signal C
Obtain the data series.

FIG. 33 shows an embodiment of the synchronous burst μ0 adding section. Based on the horizontal synchronization signal HD, vertical synchronization signal VD, and fsc signal obtained from the control signal generation section shown in FIG. 1, the control signal generation circuit 75 generates insertion gate signals for various additional signals. Also, the burst signal, μ0
A zero color reference phase signal, field information efsc'' information, etc. are also generated.

The burst signal generation circuit 76, μ00 color generation circuit 77, and synchronization pattern generation circuit 78 generate a burst signal, a 1° signal, and a synchronization pattern based on this reference phase signal. Note that all of these can be easily realized using a ROM or the like. The blanking level adding circuit 68 sets the video signal to a specific value during the blanking period. Furthermore, the burst signal addition circuit 72 inserts a burst signal within the burst signal period. Further, the μ00 color addition circuit 73 inserts the μ00 color into the video signal portion of the 263rd scanning line of the first field, for example. Furthermore, the synchronization signal addition circuit 74 inserts a 5sync pattern.

FIG. 34 shows an embodiment of the aperture correction circuit.
The output signal of the pixel delay circuit 20 is -1716, 9/8.
-1/16 is multiplied by the coefficient and added by the adder circuit 3.

FIG. 35 shows an example of adding motion information to motions that cannot be detected on the image receiving side.Motion information MDIO, MDI
Based on I, the motion determination circuit 63 detects a motion that cannot be detected on the receiving side, for example, a motion having a temporal frequency component of 30 Hz. As mentioned above, MDIO is 30 Hz
Since this frequency component is not a zero point, this frequency component is detected as motion. On the other hand, 1MDII has a zero point at 430 Hz, so this frequency component cannot be detected. Therefore, if motion is detected by MDIO but not by MIDI, the receiving side will respond to undetectable motion. ing. Therefore, in this case, the gate circuit 79
Open and output movement information.

The motion information is generated as a signal by a motion information generation circuit 64 using a ROM or the like. This information needs to be something that can be detected as movement on the image receiving side. Figure 36 shows an example of the range of the spectrum of a signal that can be used as motion information in the 1-hour vertical frequency domain. Note that this motion information appears as a kind of interference on the receiving side, so it is visually It is desirable to use something that is difficult to notice.

This concludes the description of the embodiment shown in FIG.

Another embodiment of the present invention will be described with reference to FIG. In this embodiment, the high definition information YH'vm degree signal YL.

After converting into color signal C, crosstalk components are removed.

FIG. 38 shows a block configuration of an embodiment of this crosstalk component removal.Compared with the previous FIG. It has the characteristic of being able to be transformed into Note that the time direction filter 80. The characteristics of the vertical filter 81 must be changed to those shown in FIGS. 39 and 40, respectively.

(This is because the color signal C has a signal spectrum at the position shown in No. 11.) Except for this part, this is the same as the embodiment shown in FIG. 1, so the explanation will be omitted.

Next, other embodiments of the present invention are shown in FIGS. 41 and 42. These embodiments are characterized in that the luminance signal γ compensation is handled in the form of a progressive scanning signal.

An example of the block configuration of the luminance signal γ compensation section in FIG. 41 is shown in FIG. 43, and an example of the block configuration of the luminance signal γ compensation section and YIQ change in FIG. 42 is shown in FIG. Regarding the functions, they are the same as those described above in FIG. 20, so explanations will be omitted.

Incidentally, when a horizontal and vertical two-dimensional filter is used as the LPF 44, the characteristic is that it is possible to perform γ compensation up to high vertical frequency components, as shown in FIG. However, since it is a sequential scanning signal format, the clock frequency is twice that of the interlaced scanning format, and high-speed calculation is required. Therefore, in some cases, signal processing using two channels may be necessary.

So far, the explanation has been about an example in which the three primary color input signals have been γ-corrected. Next, we will explain an example of the present invention in which the three primary color signals have not been γ-corrected. This will be explained with reference to FIG.

In FIG. 46, luminance signal γ compensation and γ correction.

The YIQ conversion section has been newly changed. An example of this block configuration is shown in FIG. 47. Y conversion circuit 38, Y17y
A luminance signal with γ compensation is generated by the conversion circuit 39 and the HP F 43. l/γ On the other hand, the R conversion circuit 83, 01'' conversion circuit 84, B1/y
Conversion (by the jjJ path 85, γ-corrected R, G, and B signals are created. These circuits can be easily realized by, for example, a t-ROM. Then, the YIQ conversion circuit 4
1 converts the luminance signal into 9 color difference signals, and the luminance signal is LPF 4.
4 and is added in an adder circuit 3 to generate a γ-compensated luminance signal.

Also in this embodiment, the position of luminance signal γ compensation or the position of crosstalk component removal is shown in FIGS. 37 and 41.
It goes without saying that modifications such as those shown in the figure are also possible.

〔Effect of the invention〕

According to the present invention, it is possible to construct a high-definition television signal with no deterioration in image quality for either still images or moving images, and the effects obtained are significant.

Although the present embodiment has been described using a sampling frequency of 8 fsc (corresponding to 4 fsc in an interlaced scanning signal), it is clear that the sampling frequency is not limited to this.

Furthermore, although the luminance signal γ compensation has been described using an example in which the horizontal frequency of the LPF is 0.5 fac, it is clear that the same holds true even if the horizontal frequency is about 0.5 MHz, for example.

Further, in the present invention, the high-frequency component of a luminance signal has been described as an example of high-definition information, but it goes without saying that, for example, a high-frequency component of a G signal or a high-frequency component of a color difference signal can be used as high-definition information.

Moreover, although the signal processing has been explained entirely digitally, it is clear that these can be realized in the form of analog signals or in the form of a mixture of analog and digital signals.

In addition, the arrangement of crosstalk component removal and luminance signal γ compensation is as follows:
It is clear that in addition to the configurations described in the embodiments, it is also effective for configurations that combine these.

Furthermore, in this embodiment, it is clear that the current NTSC television signal can be realized by omitting the functions related to high-definition signals, thereby reducing the causes of image quality deterioration.

Further, in this embodiment, a case has been described in which the subcarrier μ0 used for high-definition information multiplexing is 0.6 fac, but this μ0 is not limited to this, and other cases may be used.

For example, 0.5 fsc, 2.2 fsc,
It is clear that the present invention is effective also in cases such as 2.4 fsc. In addition, when μ0 is 4.2 MHz or more, 17m (m is an integer of 2 or more) is added to the μ0 phase information.
It is sufficient to insert a signal with a frequency of .

Regarding the audio signal, although the explanation was omitted in this embodiment, the delay time in the video signal system is compensated for by a delay circuit, etc., so that the audio signal coincides in time with the television signal obtained at the output section of the image transmission device. Needless to say, it is desirable to do so.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of a first embodiment of the present invention. Figures 2 (a) and (b) are a configuration diagram and an operating waveform diagram of an embodiment of the digital clamp section, respectively, and Figure 3 is a diagram of the YI
FIG. 4 is an explanatory diagram of the principle of aliasing distortion removal, and FIG. 5 is a block diagram of an embodiment of the aliasing distortion removal section, and FIG. 6(a) is an embodiment of the Q conversion section. (b) and (c) are the scanning line information and configuration 1 frequency characteristic diagram of one embodiment of the spatio-temporal filter 1, respectively, and Fig. 7 (a) and (
b), (Q) are respectively block diagrams of an embodiment of aliasing distortion component and motion information detection, aliasing component detection area, and motion information detection area diagrams; FIG. 8 is an embodiment of the level determination circuit;
The figure shows one characteristic of the absolute value quantization circuit, Figures 10(a) and (b)
) are continuous and binary control characteristic diagrams of the coefficient generation circuit, respectively. Moreover, FIG. 11 is a conceptual diagram of the spectrum of a high-definition television signal having compatibility, and FIG. 12(a). 13(b) is a configuration diagram and a characteristic diagram of an embodiment of the spatio-temporal filter 2, FIGS. 13(a) and 13(b) are a configuration diagram and a waveform diagram of an embodiment of the scanning line thinning and time axis expansion section, respectively. FIG. 14 shows the block configuration of an embodiment of crosstalk component removal, the first
Figure 5 shows an example of the spatiotemporal filter 3, Figure 16 shows an example of the crosstalk component detection filter, Figure 17 shows the characteristics of the crosstalk component detection filter, and Figures 18 (a) and (b) show the time direction. A configuration diagram and a characteristic diagram of the filter, FIG. 19(a). (b) is a block diagram and a characteristic diagram of an embodiment of a vertical filter, FIG. 20 is a block diagram of an embodiment of luminance signal γ compensation, FIG. 21 is an RGB conversion section, and FIG. 22 is a diagram of the luminance γ FIG. 23 shows an example of compensation and γ' characteristic conversion. In addition, Fig. 24 shows an example of HPF and LPF, and Fig. 25 (a) and (b) show horizontal one-dimensional LPF, respectively.
FIG. 26(a) is a configuration diagram and characteristic diagram of an embodiment of the present invention. (b) is a configuration diagram and a characteristic diagram of an example of a horizontal and vertical two-dimensional LPF, respectively. Also, Fig. 27 shows the block configuration of an embodiment of the high-definition information multiplexing and process circuit section, Fig. 28 shows an embodiment of filters used therein, and Figs. 29 (a) and (b) respectively show the frequency Frequency distribution diagram before and after shift, No. 30
Figures (a) and (b) are a configuration diagram and an input/output characteristic diagram of an example of modulation of high-definition information, respectively, Figure 31 is a phase explanatory diagram of subcarrier μ0 used in this, and Figure 32 (a) ,(b)
33 is an example of synchronization, burst, and μ0 signal insertion, FIG. 34 is an example of an aperture correction circuit, and FIG. (a) and (b) are respectively a configuration diagram and an explanatory diagram of an embodiment of detecting motion information that cannot be received on the receiving side, and FIG. 36 shows an area of motion information detected in 35Uj4. Further, FIG. 37 is an overall configuration diagram of the second embodiment of the present invention,
FIG. 38 shows an example of the configuration of the crosstalk component removing section in this embodiment, and (a) of FIGS. 39 and 40. (b) shows a configuration diagram and a characteristic diagram of a temporal filter and a vertical filter used here, respectively. 41 and 42 are overall configuration diagrams of the third and fourth embodiments of the present invention, respectively, and FIGS. 43 and 44 are respectively the third and fourth embodiments of the present invention. An example of luminance signal γ compensation in the fourth example,
Figure 45 shows horizontal and vertical two-dimensional diagrams in these examples.
, P F'. Further, FIG. 46 is an overall configuration diagram of a fifth embodiment of the present invention, and FIG. 47 is a configuration example of luminance signal γ compensation in this embodiment. 1...Latch circuit, 2...Level signal generation circuit, 3.
. . . Adder circuit, 4 . . . Coefficient calculation circuit, 5 .・Delay circuit 1.10...Mix circuit, 11...Scanning line thinning & time axis expansion circuit, 12...Spatio-temporal filter 2
．． 13...Delay circuit, 14...2H delay circuit, 15
...LH delay circuit, 16...520H delay circuit,
17... Coefficient multiplication circuit, 18... Absolute value quantization circuit, 19... Spatial smoothing circuit, 20... 1 pixel delay circuit, 21... Coefficient generation circuit, 22... Delay circuit ,2
3...IH memory circuit. 24... WT address generation section, 25... RD address generation section, 26... Switch, 27... Time-space filter 3.28... Delay circuit, 29... Crosstalk component detection filter, 30 ...Delay circuit, 31...Time direction filter, 32...Delay circuit, 33...Vertical direction filter, 34...525H delay circuit, 35...IHH
Delay circuit 36...RGB conversion circuit, 37...γ conversion circuit, 38...γ conversion circuit, 39...Y1''1'' conversion, 40...γ' conversion circuit, 41...YIQ Conversion circuit, 42...Multiplex circuit, 43...HPF
, 44...LPF, 45...delay circuit, 46...
Delay circuit, 47...delay circuit, 48...γ power circuit,
49...1/γ power circuit, 50...γ/γ fifth power circuit,
51...Delay circuit, 52...Horizontal LPF circuit, 53
...HPFYH circuit, 54...Modulator, 55...
Subcarrier generation circuit, 56...LPFYH' circuit,
57...LPFYL circuit, 58...LPFI circuit,
59...LPFQ circuit, 60...Orthogonal modulation circuit, 6
DESCRIPTION OF SYMBOLS 1... Delay circuit, 62... Delay circuit, 63... Motion determination circuit, 64... Motion information generation circuit, 65...
Synchronous burst signal addition circuit, 66... Aperture correction circuit, 67... Delay circuit, 68... Blanking addition circuit, 69... Phase information generation circuit, 70... Multiplication circuit, 71... Polarity inversion control circuit, 72... Burst signal addition circuit, 73... μ0 signal addition circuit, 74.
...Synchronization pattern addition circuit, 75...Control signal generation circuit, 76...Burst signal generation circuit, 77...μO
Signal generation circuit, 78... Synchronization pattern generation circuit, 79
...Gate circuit, 80...Time direction filter, 81
...Vertical filter, 82...Delay circuit, 83.
...R1″1″ conversion, 84...01″ conversion circuit, 85
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No. 1 Hitachi, Ltd. Internal telephone: Tokyo 212-1111 (main representative) Details of the amendment The drawing, Figure 35, will be amended as shown in the attached amended drawing.

Claims (1)

[Claims] 1. Means for performing signal processing on a video signal obtained from a camera imaging system to reduce factors of image quality deterioration not only in the horizontal frequency domain but also at least in the vertical frequency domain, or in the two-dimensional or three-dimensional frequency domain of the time-frequency domain. An image transmission device for a television signal, comprising: