JP2865853B2 - Waveform equalizer - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a waveform equalizer such as a ghost remover for a television receiver.

[Conventional technology]

Conventionally, one of the problems of television signals sent from broadcasting stations
One is a waveform distortion such as a ghost. There is a waveform equalizer as a technique for removing the waveform distortion.

FIG. 14 shows a conventional waveform equalizer. In the figure, 101 is a waveform equalizing means, 202 is a storage means, and 203 is
The waveform distortion detecting device 204 is an arithmetic device, and 205 is a waveform equalizing means control device.

The waveform equalizing means 101 removes waveform distortion from the input composite video signal. Next, the storage means 202 stores a GCR signal (Chost Cancel Reference S) from the output of the waveform equalization means 101.
ignal: For details, refer to Official Gazette No. 155, August 1, 1989, Ordinance No. 48 of the Ministry of Posts and Telecommunications) or take out only a reference signal such as a synchronization signal and perform synchronous addition to reduce noise.
The waveform distortion detection device 203 detects the waveform distortion from the error by comparing the reference waveform with the waveform from the storage unit 202. Further, the arithmetic unit 204 generates, from the output of the waveform distortion detection unit 203, data corresponding to each frequency for controlling the waveform equalization unit 101 so as to have a characteristic of removing the waveform distortion. Accordingly, the waveform equalizer control device 205 controls the waveform equalizer 101 according to the output of the arithmetic device 204, and operates the waveform equalizer 101 to perform waveform equalization.

The waveform equalizing means 101 can be realized by a traversal filter having a gain corresponding to each frequency in order to flatten frequency characteristics.

FIG. 15 shows a configuration of a general transversal filter. In the figure, 301 is a delay device, 302 is a multiplication device, and 303 is an addition device. τ is the delay time of the delay device 301.

One set of the delay device 301 and the multiplication device 302 constitutes one tap. The addition device 303 adds the outputs of the taps and outputs the result.

Conventionally, as this type of device, for example,
No. 59791 can be mentioned.

In this already-proposed example, not only is the waveform equalizing means configured to remove the waveform distortion, but also the S / N
When the image quality was bad, the image quality was automatically reduced to make it easier to see. Further, when the S / N ratio is poor, the image quality is lowered even if the waveform equalization is somewhat incomplete, so that the image becomes tolerable to some extent.

[Problems to be solved by the invention]

In a conventional waveform equalizer, generally, the frequency characteristics of an input signal are flattened by a waveform equalizer in order to remove waveform distortion of the input signal.

However, even when the S / N of the input signal is good, when the high frequency component of the input signal is small (that is, when the high frequency level of the input signal is low), the frequency characteristics of the input signal are flattened. To increase the level of the high frequency of the input signal,
Accordingly, a small amount of noise included in the high frequency range of the input signal is also amplified, and the S / N is deteriorated. As a result, there is a problem that the image on the screen becomes rough.

Conversely, when the input signal has many high-frequency components (ie,
If the high level of the input signal is high), the level of the high frequency of the input signal is reduced in order to flatten the frequency characteristics of the input signal, thereby significantly reducing the high frequency component of the input signal. As a result, the image on the screen has a significantly softer image quality visually, and as compared with a case where the frequency characteristics of the input signal are not flattened.
There was a problem that it looked blurred.

The present invention determines a change in the frequency characteristic due to the input video signal having undergone waveform equalization, and if it is determined that the high frequency level has fallen beyond a certain range, the waveform equalization is performed. After that, the image quality of the video signal is increased (increased in sharpness) to reduce the visual blurring of the image. On the other hand, the determination result of the frequency characteristic change indicates that the level of the high frequency band is increased. If the image signal has undergone waveform equalization, the S / N
It is an object of the present invention to suppress deterioration of the image quality and always obtain an optimum image quality.

[Means for solving the problem]

In order to achieve the above object, according to the present invention, a waveform equalizer for receiving a composite video signal, removing waveform distortion of the composite video signal according to a separately input first control signal, and outputting the composite video signal, An image quality control device that receives a composite video signal output from the waveform equalization unit, adjusts the image quality of the composite video signal according to a second control signal that is separately input, and outputs the adjusted composite video signal;
Waveform distortion extraction for receiving a composite video signal output from the waveform equalizing means, detecting waveform distortion of the composite video signal, and generating the first and second control signals based on the detected waveform distortion; A waveform equalizer including a control unit, wherein the waveform distortion extraction / control unit is configured to store the input composite video signal, and to extract the waveform distortion from the composite video signal stored in the storage unit. A waveform distortion detection device for detecting,
An arithmetic unit for generating the first control signal from the detected waveform distortion; a waveform equalization unit control unit for outputting the generated first control signal to the waveform equalization unit; A frequency characteristic determination device that determines a change in the frequency characteristic of the composite video signal from the control signal, generates the second control signal according to the determined change, and outputs the second control signal to the image quality control device. I did it.

[Action]

The waveform equalizing means flattens the frequency characteristics of the input signal and outputs the signal. The waveform distortion extraction / control unit detects whether the output of the waveform equalization unit contains a waveform distortion, and if the waveform distortion is included, the waveform equalization unit removes the waveform distortion. Control means. At the same time, the waveform distortion extraction / control means detects a change in frequency characteristics caused by removing the waveform distortion. The image quality control device controls the image quality (sharpness) based on the output of the waveform distortion extraction / control device. According to this method, it is possible to cancel the deterioration of S / N and the feeling of blurring that occur when the frequency characteristic is significantly corrected before and after waveform equalization.

〔Example〕

 FIG. 1 conceptually shows a first embodiment of the present invention.

In the present embodiment, a composite video signal is input, a waveform equalizer 101 that removes and outputs a waveform distortion such as a ghost, and an output of the waveform equalizer 101 is input to reduce a waveform distortion such as a ghost. Detecting and controlling the waveform equalizing means 101, and inputting the output of the waveform distortion extracting / controlling means 102 for controlling the image quality control device 103 and the output of the waveform equalizing means 101,
And an image quality control device 103 for controlling and outputting the image quality (especially sharpness) by the output of the control means 102.

That is, the waveform equalization means 101 is controlled by the waveform distortion extraction / control means 102 to have a characteristic that enables waveform equalization,
Removes waveform distortion from the input signal. Further, the image quality control device 103 detects a change in the frequency characteristic from the output of the waveform distortion extraction / control means 102, and controls the image quality accordingly.

FIG. 2 shows a more detailed configuration of the waveform equalizer of FIG. 2, the same components as those in FIG. 1 or FIG. 14 are denoted by the same reference numerals. In addition, reference numeral 206 denotes a frequency characteristic determination device (hereinafter, abbreviated as f characteristic determination device).

For the waveform equalizing means 101, a transversal filter is used. The output of the waveform equalizing means 101 is temporarily stored in a storage means 202 in order to reduce noise by synchronously adding a reference signal such as a GCR signal or a synchronization signal. Next, the waveform distortion detection device 203 detects the waveform distortion by comparing the output of the storage means 202 with a reference waveform which is stored in advance. Then, the arithmetic unit 204 uses the output of the waveform distortion detecting unit 203 to calculate a characteristic by which the waveform equalizing means 101 can equalize the waveform. Specifically, the gain of each tap of the transversal filter is calculated by the following equation (ZF method)
Calculate by

C _i ⁽ⁿ⁾ = C _i ⁽ⁿ⁻¹⁾ −αe _i ⁽ⁿ⁾ C ⁽ⁿ⁾ : Gain calculated at the n-th tap of the i-th tap α: Feedback coefficient e _i ⁽ⁿ⁾ : Calculated at the n-th tap The error equal to the reference signal corresponding to the i-th tap The waveform equalizer control unit 205 inputs the calculation result of the arithmetic unit 204 to the waveform equalizer 101, and the waveform equalizer 101 performs waveform equalization. Control to possible properties. Further, the f determination device 206 determines a change in the frequency characteristic after waveform equalization from the same calculation result of the calculation device 204 input to the waveform equalization device control device 205, and lowers the high frequency range. In this case, a control signal is output to the image quality control device 103 so as to increase the image quality and to reduce the image quality when the high range is increased. Then, the image quality control device 103 calculates the image quality by using the output of the f characteristic determination device 206.

The above is the outline of the operation. Hereinafter, a method of determining a change in the frequency characteristic will be described.

In the transversal filter shown in FIG. 15, one tap is composed of one delay device 301 and one multiplication device 302, and an addition device 303 adds and outputs the output of the multiplication device 302. The figure shows the case of three taps. τ is
The delay times a1, a2, and a3 of the delay device are tap gains applied to the input signal by the multiplier.

The transversal filter divides the input signal into a main signal having a gain of 1 passing through a main tap and a signal delayed by nτ (n: an integer) from the main signal, and controlling the gain of signals other than the main signal to control the main signal. , Filters having various frequency characteristics can be realized. When the signal with the delay time τ from the main signal and the main signal are added, the phase of the 1 / τ frequency component becomes the same and the amplitude increases. Also, 1/2
The phase of the frequency component of τ is reversed and the amplitude is reduced.
For this reason, the output of each delay device of the transversal filter emphasizes or attenuates the frequency component of the reciprocal of the delay time from the main signal according to each tap gain.

FIG. 3 simply shows the gain of each tap with respect to the characteristics of three types of input signals.

FIG. 9A shows a case where the high frequency of the input signal is raised, and the gain of Tap1 (1 / τ) corresponding to the high frequency on the frequency axis.
a1 decreases the gain, and the gain a3 of Tap3 (1 / 3τ) corresponding to the low band has such a magnitude as to increase the gain. FIG. 6B shows a case where the high frequency of the input signal is lowered. In this case, a1 is increased in order to raise the high frequency. Finally, FIG. 9C shows a case where the frequency characteristics of the input are flat. At this time, since the output may be performed as it is, the gain is 0 for each tap. From the above, when the tap gain after the correction is viewed, the correction amount of the f characteristic can be known.

FIG. 4 shows a first specific example of the f characteristic determination device 206 in FIG. In the figure, 501 is an address determination device, 502 is a data register, 503 is a level determination device,
Reference numeral 504 denotes an image quality control signal generation device.

The number (Tap1 to Tap) of each tap of the transversal filter is sequentially sent from the arithmetic unit 204 to the address determination unit 501,
The gain (a1 to an) of each tap at that time is similarly input to the data register 502. When the address of a specific tap is input, the data register 502 holds the tap gain corresponding to the address, and determines whether the image quality should be increased, decreased, or not changed from the tap gain at this time. The determination is made by the determination device 503. An image quality control signal generation device 504 generates a signal for controlling the image quality control device 103 from the output of the level determination device 503.

FIG. 5 shows the image quality control signal generator 504 in FIG.
An example is shown below. In the figure, TR1, TR2, and TR3 are transistors, and R1, R2, R3, R4, and R5 are resistors.

From the output of the level determination device 503, when the voltage of the terminal U for improving image quality is at the H level, the transistor TR1
Is turned on and the transistor TR3 is also turned on, so that the output voltage to the image quality control device 103 increases. When the voltage of the terminal D for lowering the image quality is at the H level, the transistor TR2 is turned on, and the output voltage to the image quality control device 103 decreases. When both of the terminals U and D are at the L level, no control signal is sent to the image quality control device 103 and the image quality is not changed. As described above, in this specific example, the image quality can be controlled in three stages according to the characteristics of the input signal.

FIG. 6 shows a second specific example of the f characteristic determination device 206 in FIG. In the figure, 502 'is a data register, and 505 is an adder.

In this specific example, the gain of a plurality of taps is used. That is, the output of the arithmetic unit 204 is input to the address determining unit 501 and the data register 502 ', as in the case of FIG. The address judging device 501, when a plurality of taps selected in advance, or the address of all taps is input, the data register 50
2 ′ holds the data at that time. The outputs (D1 to Dm: m ≦ n) from the data register 502 ′ are added by an adder 505, and the output of the adder 505 is output to the level determination device 503.
The image quality control signal generator 504 generates a signal for controlling the image quality controller 103 in the same manner as in FIG. It should be noted that more optimal characteristics can be obtained by weighting the input of the adder 505.

FIG. 7 shows a third specific example of the f characteristic determination device 206 in FIG. In the figure, 505 'is an adder, 506
Is a delay device.

This example also uses multiple taps. Therefore, the difference from the f characteristic determination device shown in FIG.
505 '. The adder 505 'adds the data one by one by using a delay unit 506 instead of adding the data at one time, so that only one output of the data register 502 is required. 505 'also does not need to be multi-input, and can be small in scale.

FIG. 8 shows a fourth specific example of the f characteristic determination device 206 in FIG. In the figure, reference numeral 503 'denotes a level determining device, and 504' denotes an image quality control signal generating device.

In this specific example, multi-value control is performed. That is, the output of the adder 505 is divided into a plurality of levels (upper 1 to lower 1 and lower 1 to lower 1) by a level judgment device 503 ', and the image quality control device 103 is multi-staged by an image quality control signal generation device 504'. To generate a control signal. In addition, the image quality can be continuously controlled by converting the image into a continuous amount.

FIG. 9 shows the image quality control signal generator 50 shown in FIG.
A specific example of 4 'is shown. In the figure, reference numeral 1204 denotes a D / A converter.

The output of the level determination device 503 'is input to a D / A conversion device 1204. The D / A conversion device 1204 is provided with the level determination device 5
A continuous output signal is generated according to the output of 03 '. As described above, in this specific example, the image quality can be continuously controlled according to the characteristics of the input signal.

FIG. 10 shows a specific example of the image quality control device 103 in FIG. In the figure, 1001 and 1002 are delay devices, 100
3,1005 is a multiplication device, and 1004,1006 are addition devices.

The output A of the waveform equalizing means 101 is delayed by the delay device 1001 to obtain the output B, and the output B of the delay device 1001 is delayed by the delay device 1002 to obtain the output C. The output C of the delay device 1002, the output B of the delay device 1001 and the waveform equalizing means 101
Is calculated by the multiplication device 1003 and the addition device 1004 to extract a specific frequency component to obtain an output E. The output E of the adder 1004 is amplified or attenuated by the output of the waveform distortion extraction / control means 102 to obtain an output F, and the output F is added to the output B of the delay device 1001 by the adder 1006. As a result, a specific frequency component can be emphasized or attenuated.

Next, FIG. 11 conceptually shows a second embodiment of the present invention.

This embodiment receives a composite video signal, receives waveform distortion such as a ghost by inputting the composite video signal before waveform equalization, and a waveform equalizer that removes waveform distortion such as a ghost,
The image quality control means 103 while controlling the waveform equalization means 101
And the waveform distortion extraction / control means 102 ', which receives the output of the waveform equalization means 101, and outputs the waveform distortion extraction / control means 1
Image quality control device that controls and outputs image quality with the output of 02 '
103.

That is, the waveform equalizing means 101 is controlled by the waveform distortion extracting / controlling means 102 'to have a characteristic capable of performing waveform equalization, and removes waveform distortion from an input signal. Further, the image quality control device 103 detects a change in the frequency characteristic from the output of the waveform distortion extraction / control means 102 ', and controls the image quality accordingly.

FIG. 12 shows a more detailed configuration of the waveform equalizer of FIG. In the figure, reference numeral 1101 denotes a Fourier transform unit, 1102
Is a first arithmetic unit, 1103 is an inverse Fourier transform unit, 1104
Is a second arithmetic unit.

The composite video signal is input to the waveform equalizing means 101 and the Fourier transform means 1101. The Fourier transform unit 1101 performs a Fourier transform on the input composite video signal. First arithmetic unit 11
02 has the output of the Fourier transform means and has in advance
By calculating the Fourier transform of a reference signal such as a GCR signal or a synchronization signal, a transfer characteristic in the waveform equalizing means 101 is obtained. And the inverse Fourier transform means 11
03 performs an inverse Fourier transform on the transfer characteristic. The Fourier transform and the inverse Fourier transform can be realized by using an algorithm such as FFT (Fast Fourier Transform) using a microprocessor. Please refer to them).

The second arithmetic unit 1104 generates a waveform equalization control signal for controlling the waveform equalization unit 101 from the output of the inverse Fourier transform unit 1103. Further, the waveform equalizer control unit 205 controls the waveform equalizer 201 based on the output of the second arithmetic unit 1104 to perform waveform equalization. Also, the f-characteristic determining unit 206 determines the frequency characteristics of the input composite video signal from the output of the second arithmetic unit 1104, and outputs a signal for controlling the image quality to the image quality control unit 207. In addition,
It goes without saying that the output of the waveform equalizer control unit 205 or the control information held in the waveform equalizer 101 may be used as the input of the f-characteristic determination unit 206.

Next, FIG. 13 conceptually shows a third embodiment of the present invention. In the figure, reference numeral 104 denotes a luminance signal separating unit.

In the present embodiment, a luminance signal separating unit 104 is provided between the waveform equalizing unit 101 and the image quality control device 103.

The luminance signal separating unit 104 separates the output of the waveform equalizing unit into a luminance signal Y and a chrominance signal C, and outputs only the luminance signal Y to the image quality control device 103. Therefore, the image quality control device 103 performs image quality control only on the luminance signal Y. this is,
The luminance signal Y includes a frequency component from 0 to 4.2 MHz,
The image quality can be controlled by emphasizing or attenuating a specific frequency component.
Since the phase of the carrier chrominance signal of MHz has color information and the amplitude of the color chrominance information, respectively, the image quality control device 103 controls the image quality control by the color signal C when distortion is included. This is because if the above is also performed, there is a possibility that the color tone and the color density may become unnatural.

It should be noted that the above configuration can be realized by software using a microcomputer or the like.

〔The invention's effect〕

As described above, according to the present invention, the S /
When N is good and the high frequency component of the input signal is small (that is,
Even when the level of the high frequency of the input signal is low), the change in the frequency characteristic due to the waveform equalization of the input signal is detected, and the image quality is adjusted accordingly, whereby the S / S
It is possible to suppress deterioration of N and obtain an optimal image.

Conversely, when the input signal has many high-frequency components (ie,
Even when the high level of the input signal is high), a change in the frequency characteristics due to the waveform equalization of the input signal is detected, and the image quality is adjusted accordingly, so that the blur that is visually perceived It is possible to eliminate the feeling and obtain an optimal image.

Also, from the output of the arithmetic unit that calculates the characteristics of the waveform equalizing means at the same time as the waveform equalization, the change in the frequency characteristics due to the input signal waveform equalization is known, and control is performed so that the image quality is always optimized. Therefore, the number of new means to be added can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram conceptually showing a first embodiment of the present invention, FIG. 2 is a block diagram showing a more detailed configuration of the waveform equalizer in FIG. 1, and FIG. 3 is a waveform in FIG. FIG. 4 is an explanatory diagram showing the gain of each tap with respect to the characteristic of the input signal in the equalizing means, FIG. 4 is a block diagram showing a first specific example of the f-special judgment device 206 in FIG. 2, and FIG. FIG. 6 is a circuit diagram showing a specific example of the image quality control signal generation device 504, FIG. 6 is a block diagram showing a second specific example of the f characteristic determination device 206 in FIG. 2, and FIG. 7 is an f characteristic determination in FIG. FIG. 8 is a block diagram showing a third specific example of the device 206, and FIG.
FIG. 9 is a block diagram showing a fourth specific example of the f characteristic determination device 206 in FIG. 9, and FIG. 9 is an image quality control signal generation device in FIG.
FIG. 10 is a block diagram showing a specific example of an image quality control device 103 in FIG. 1;
FIG. 11 is a block diagram conceptually showing a second embodiment of the present invention, FIG. 12 is a block diagram showing a more detailed configuration of the waveform equalizer of FIG. 11, and FIG. FIG. 14 is a block diagram conceptually showing a third embodiment, FIG. 14 is a block diagram showing a conventional waveform equalizer, and FIG. 15 is a block diagram showing a configuration of a general transversal filter. EXPLANATION OF SYMBOLS 101: waveform equalization means, 102, 102 ': waveform distortion extraction /
Control means 103 image quality control apparatus 104 luminance signal separation means 202 storage means 203 waveform distortion detection apparatus 204
1102, 1104, 307 arithmetic unit, 205 waveform equalization unit control unit, 206 f special determination unit, 1101 Fourier transform unit, 1103 inverse Fourier transform unit, 501 address determination unit, 502,502 '... data register, 503,503' ...
Level determination device, 504, 504 '... image quality control signal generation device, 505, 505', 1004, 1006 ... addition device, 506 ... delay device, 1001, 1002 ... delay device, 1003, 1005 ... multiplication device
1204 ... D / A converter.

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Sekiya 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Within Hitachi Video Engineering Co., Ltd. (72) Katsumi Hishiyama 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Hitachi, Ltd. Inside the factory Yokohama factory (72) Inventor Nao Suzuki 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Yokohama-shi Within Hitachi Video Engineering Co., Ltd. (58) Field surveyed (Int.Cl. ⁶ , DB name) H04N 5/14-5 / 217

Claims (12)

(57) [Claims] 1. A waveform equalizing means for receiving a composite video signal, removing waveform distortion of the composite video signal in accordance with a separately input first control signal, and outputting the composite video signal, and outputting from the waveform equalizing means. And a composite video signal output from the waveform equalizing means, wherein the composite video signal output from the waveform equalizing means receives a composite video signal to be input and adjusts and outputs the image quality of the composite video signal according to a second control signal input separately. And a waveform distortion extraction / control means for detecting waveform distortion of the composite video signal and generating the first and second control signals based on the detected waveform distortion. In the above, the waveform distortion extraction / control means includes a storage means for storing the input composite video signal, a waveform distortion detection device for detecting the waveform distortion from the composite video signal stored in the storage means, Generating the first control signal from distortion An arithmetic unit that outputs the generated first control signal to the waveform equalizing unit; and a controller that generates the first control signal.
A frequency characteristic determination device that determines a change in the frequency characteristic of the composite video signal from the control signal, generates the second control signal in accordance with the determined change, and outputs the second control signal to the image quality control device. A waveform equalizer characterized by the following. 2. A waveform equalizing means for receiving a composite video signal, removing waveform distortion of the composite video signal in accordance with a separately input first control signal, and outputting the composite video signal, and outputting from the waveform equalizing means. An image quality control device that inputs a composite video signal to be input, adjusts the image quality of the composite video signal according to a second control signal that is separately input, and outputs the composite video signal. A waveform distortion extraction / control means for receiving a signal, detecting waveform distortion of the composite video signal, and generating the first and second control signals based on the detected waveform distortion. In the apparatus, the waveform distortion extracting / controlling means includes a Fourier transforming means for performing a Fourier transform on the input composite video signal, and a first arithmetic operation for deriving a transfer characteristic in the waveform equalizing means from the Fourier-transformed composite video signal. Equipment and Inverse Fourier transform means for performing an inverse Fourier transform on the derived transfer characteristic, a second arithmetic unit for generating the first control signal from the inverse Fourier-transformed transfer characteristic, and converting the generated first control signal to the waveform or the like. A control unit for outputting a waveform equalizing means, and a change in a frequency characteristic of the composite video signal is determined from the generated first control signal, and the second control signal is generated in accordance with the determined change. And a frequency characteristic determination device that outputs the frequency characteristic to the image quality control device. 3. A waveform equalizer according to claim 1, wherein a composite video signal output from said waveform equalizing means is input, and a luminance signal is output by separating a luminance signal from said composite video signal. Separation means is provided, and the image quality control device inputs a luminance signal output from the luminance signal separation means instead of the composite video signal output from the waveform equalization means,
A waveform equalizer that adjusts and outputs the image quality of the luminance signal according to the second control signal that is separately input. 4. The waveform equalizer according to claim 1, 2 or 3, wherein said waveform equalizer is composed of a transversal filter, and said frequency characteristic determination device is configured to generate said first waveform. A waveform equalizer, wherein a change in a frequency characteristic of the composite video signal is determined using only control information for a single tap of the transversal filter among the control signals. 5. The waveform equalizer according to claim 4, wherein
The frequency characteristic determination device includes: a data register that inputs information regarding the tap gain of the tap among the control information of the first control signal, temporarily holds and outputs the data, Out of the control information of
Information on the tap number of the tap, and an address determination device for controlling the data register according to the information; and based on the information output from the data register, whether to increase or decrease the image quality or not to change the image quality. And an image quality control signal generation device that generates the second control signal based on the determination result of the level determination device and outputs the second control signal to the image quality control device. Waveform equalizer. 6. A waveform equalizer according to claim 1, 2 or 3, wherein said waveform equalizer comprises a transversal filter, and said frequency characteristic judging device generates said first waveform. A waveform equalizer, wherein a change in frequency characteristics of the composite video signal is determined using control information for a plurality of taps of the transversal filter among control signals. 7. The waveform equalizer according to claim 6, wherein:
The frequency characteristic determination device, among the control information of the first control signal, information on the tap gain of the plurality of taps is input in parallel, a data register that temporarily holds and outputs the data in parallel, An address judging device for inputting information on the tap numbers of the plurality of taps among the control information of the first control signal and controlling the data register in accordance with the information, and outputting in parallel from the data register Information to be input, added and output by adding, based on the information output from the addition means,
A level determining device for determining whether the image quality is to be increased or decreased or not to be changed; and an image quality control signal for generating the second control signal based on the determination result of the level determining device and outputting the second control signal to the image quality control device. A waveform equalizer, comprising: a generator. 8. The waveform equalizer according to claim 6, wherein:
The frequency characteristic determination device, among the control information of the first control signal, information on tap gains of the plurality of taps is input in series, and a data register that sequentially holds and outputs serially, An address judging device for inputting information relating to the tap numbers of the plurality of taps among the control information of the first control signal and controlling the data register in accordance with the information, and serially outputting the data from the data register Adding means for inputting information to be output and information output from the delay means, adding and outputting the information, the delay device for inputting information output from the adding means, delaying and outputting the information, and the adding means Based on the information output from, a level determination device that determines whether to increase or decrease the image quality or not change, based on the determination result of the level determination device, Serial second generates a control signal, the quality control and quality control signal generating device outputs the device, in the waveform equalizer, characterized in that it is configured. 9. The waveform equalizer according to claim 5, wherein the level determining device increases or decreases the image quality when determining whether to increase or decrease the image quality. A waveform equalizer characterized in that the determination as to whether or not it is performed is also performed. 10. The waveform equalizer according to claim 9, wherein said level determination device outputs said determination result as a digital signal to said image quality control signal generation device, and said image quality control signal generation device outputs a digital signal. / Analog conversion device, wherein the input digital signal is converted into an analog signal and output to the image quality control device as the second control signal. 11. The waveform equalizer according to claim 1,2,3,4,5,6,7,8,9 or 10, wherein the image quality control device is arranged such that each tap has a position relative to a tap gain. A waveform equalizer, comprising a transpersal filter arranged to be symmetrical. 12. The waveform equalizer according to claim 11, wherein the image quality control device includes a plurality of delay devices that receive an output of the waveform equalizer and delay the output. A plurality of first multipliers for providing gains to the outputs of the first and second delay devices, a first adder for adding the outputs of the first multiplier, and an output of the first adder. A second multiplier for changing the magnitude according to the output of the waveform distortion extractor / controller; and a main signal temporally centered among the inputs of the plurality of first multipliers and the second multiplier. And a second adder for adding the outputs of the waveform equalizers.