KR950004113B1 - Edge compensation signal generating apparatus - Google Patents

Abstract

The generator includes a first delaying circuit for delaying the image signal input through an input terminal as many as the time difference of the time constant; a first subtracting circuit for forming a frame correction signal from the image signal delayed from the first delaying circuit and the input terminal signal; a second delaying circuit for further delaying the delayed signal of the first delaying circuit as many as the time constant; and a second subtracting circuit for forming the frame correction signal from the output signals of the first and second delaying circuits.

Description

Contour correction signal generator

1 is a block diagram of a conventional lubrication correction signal generator.

2 is a waveform diagram of each part of FIG.

3 is a block diagram of a circuit in which contour correction time is reduced according to the present invention.

4 is a block diagram of a high frequency correction output guarantee circuit according to the present invention.

5 is another exemplary embodiment of the present invention.

(A)-(c) of FIG. 6 are the wave form diagrams of FIG.

(A) to (e) of FIG. 7 are respective waveform diagrams of FIG.

8 is a characteristic diagram of a coding circuit portion in FIG.

9 is a characteristic view of FIG.

* Explanation of symbols for main parts of the drawings

1: Input terminal 2: First delay circuit

3: first subtraction circuit section 4,7: 1/2 times amplification section

5: second delay circuit section 6: second subtraction circuit section

8: addition circuit section 9: gain control amplifier section

10: output terminal 11: first amplifier

12: second amplifier 13: switching unit

14,18: part polarity inverting part 15: level setting part

16: comparison unit 17: trade pass filter unit

19: limiter 20: coding circuit

21 DC voltage supply 22 22 third subtraction circuit

23: smoothing circuit part.

The present invention relates to a contour correction signal generator of a high-definition TV receiver display apparatus, and in particular, to generate a sharpness of a portion of the image signal generating the contour correction signal and a contour correction signal corresponding to the high frequency component of the video signal around the image signal. The present invention relates to a contour correction signal generator that is suitable for good contour correction that matches well with the contents of an image throughout a reproduced image.

As shown in FIG. 1, the conventional contour correction signal generator includes a first delay circuit unit 2 for delaying an image signal input through the input terminal 1 by a time difference of time constant? A first subtraction circuit section 3 for forming a contour correction signal from a video signal delayed by the delay circuit section 2 and a signal of the input terminal 1, and an output delayed by a time constant τ of the first delay circuit section 2; A second delay circuit section 5 for further delaying the signal by a time constant? And a second subtraction circuit section 6 for forming a contour difference from the output signals of the first and second delay circuit sections 2 and 5; And a half-time amplifiers 4 and 7 for adjusting the magnitude of the contour correction signal generated by the first and second subtraction circuits 3 and 6. 4) and an addition circuit section 8 for completing the leap and correction signals amplified in (7) into one contour correction signal, and the gain of the contour correction signal completed in the addition circuit section 8 by adjusting the output stage 10. to It consists of the gain control amplifier 9 which outputs.

In the conventional contour correction signal generating device configured as described above, an image signal having a waveform as shown in FIG. 2 (A) is input to the input terminal 1, and the original contour correction signal generating device is obtained as shown in FIG. When the signal passes through the second delay circuit section 5 once more than the input signal, and the signal passes through the second delay circuit section 5, the time constant (2τ) is twice that of the original input signal as shown in (c) of FIG. As long as the signal is delayed.

The video signal input as shown in (a) of FIG. 2 and the video signal delayed by the time constant (τ) as shown in (b) of FIG. 2 are corrected for contours as shown in (d) of FIG. 2 through the first subtraction circuit unit 3. The video signal which forms a part of the signal and is similarly delayed by the time constant (τ) as shown in (b) of FIG. 2 and the delayed by the time constant (2τ) by 2 times as shown in (c) of FIG. A part of the contour correction signal as shown in FIG. 2E is formed through the circuit unit 6.

Each contour correction signal formed through the first and second subtracting circuit parts 3 and 6 has an amplitude adjusted through the 1/2 times amplifying parts 4 and 7, respectively, It is synthesized and output as a completed outline correction signal as shown in FIG.

After the gain is properly adjusted through the gain control amplifier 9, the completed contour correction signal is loaded through the output terminal 10 so as to be loaded on the video signal delayed by the time constant τ to actually emphasize the contour. Is output.

However, the contour-enhanced video signal formed by adding such a contour correction signal by the conventional contour correction signal generator to the original video signal includes a rising portion of the waveform than the original video signal as shown in (g) of FIG. The width of the falling portion is further extended by 2τ, and the phenomenon in which the widths of the rising portion and the falling portion of the video signal are expanded is uniform regardless of whether the change of the corresponding video signal is sharp or gentle.

Therefore, in the case of a very fine image where the change of the image signal is very severe, such a phenomenon may cause distortion of the waveform of the signal adjacent to the corresponding signal portion, and the gain adjustment of the contour correction signal is uniformly performed. The same degree of contour correction is applied to monotonous images with almost no signal changes and precise images with significant changes in video signals. When the entire screen is viewed, noise appears due to excessive contour correction. In this case, there is a problem in that the viewer is heterogeneous due to a defect such that the screen is not clearly reproduced due to insufficient outline correction.

In view of such a problem, the present invention adjusts the time width of the contour correction signal in consideration of the amplitude of the contour correction signal composed of delayed video signals, thereby narrowing the contour of the narrow time width for the sharp image of which the change of the video signal is sharp. An apparatus for generating a contour correction signal capable of reproducing a clear image by adding a correction signal is described. The detailed description will be given below with reference to the accompanying drawings.

As shown in FIG. 3, the circuit having reduced contour correction time according to the present invention includes a first delay circuit section 2 which delays an image signal input through the input terminal 1 by a time difference of time constant τ. A first subtraction circuit section 3 for forming a contour correction signal from the video signal delayed by the first delay circuit section 2 and the signal of the input terminal 1, and the time constant of the first delay circuit section 2; A contour correction signal is formed from the second delay circuit section 5 which further delays the output signal delayed by (Z) by the time constant τ and the output signals of the first and second delay circuit sections 2 and 5. The second subtraction circuit section 6 and the first and second amplification sections 11 and 12 for amplifying the contour correction signal formed by the first and second subtraction circuit sections 3 and 6, An addition circuit section 8 which completes the outline correction signal adjusted by the first and second amplifying sections 11 and 12 into one correction signal, and outputs the output of the addition circuit section 8 to the output terminal 10. Output and cut off A partial polarity inversion part 14 for providing only a positive value for the part 13, a part of the contour correction signal gain-adjusted in the first amplification part 11, and this partial polarity inversion part ( A level setting section 15 which receives the output of 14) and generates a DC voltage proportional to the magnitude of the amplitude of the contour correction signal, and the DC voltage value output from the level setting section 15 in the addition circuit section 8; The calculated contour correction signal and the comparison unit 16 for turning on / off the switching unit 13 are configured.

As shown in FIG. 4, the high frequency correction output reinforcement circuit according to the present invention includes a first delay circuit section 23 for delaying an image signal input through the input terminal 1 by a time difference of time constant? The first subtraction circuit section 3, which forms a contour correction signal from the video signal delayed by the first delay circuit section 2 and the signal of the input terminal 1, and the time constant τ of the first delay circuit section 2; A second delay circuit section 5 for further delaying the output signal delayed by the time constant τ and a second contour forming signal from the output signals of the first and second delay circuit sections 2 and 5; First and second amplification parts 11 and 12 for amplifying the subtraction circuit part 6 and the contour correction signal formed by the first and second subtraction circuit parts 3 and 6, and the first delay. A high pass filter unit 17 for filtering high frequency components from the output signal of the circuit unit 2, and a part of the configuration that makes the value of the output waveform middle sound of the high pass filter unit 17 positive. A limiter 19 for passing only a waveform having a magnitude within a predetermined range of the inverting section 18, the output waveform of the partial polarity inverting section 18, and a limit of more than a predetermined range at the output of the partial polarity inverting section 18; A coding circuit section 20 for passing only a waveform having a magnitude, a DC voltage supply section 21 for applying a reference voltage to the limiter 19 and the coding circuit section 20, and the limiter 19 and a coding circuit section 20. Smoothing the third subtracting circuit section 22 for calculating the difference between the outputs of?) And the gains of the first and second amplifying sections 11 and 12 by smoothing the output of the third subtracting circuit section 22. The circuit section 23 and the addition circuit section 8 for calculating the contour correction signal from the thrust signals of the first and second amplifying sections 11 and l2 and outputting the contour correction signal to the output terminal 10.

According to another embodiment of the present invention, as shown in FIG. 5, the first delay circuit unit 2 delays the video signal input through the input terminal 1 by a time constant? A first subtraction circuit section 3 for forming a contour correction signal from the video signal delayed by the circuit section 2 and a signal of the input terminal 1, and an output signal delayed by a time constant? Of the first delay circuit section 2; Second delay circuit section 5 for further delaying? By a time constant?, And second subtraction circuit section 6 for forming a contour correction signal from the output signals of the first and second delay circuit sections 2 and 5; ), First and second amplifiers 11 and 12 for amplifying the contour correction signal formed by the first and second subtraction circuits 3 and 6, and the first delay circuit unit 2; A high pass filter unit 17 for filtering high frequency components from the output signal of the signal, a part of the polarity inverting unit 18 which makes negative values of the output waveforms of the high pass filter unit 17 positive, Polarity A limiter 19 for passing only waveforms having a size within a predetermined range in the output waveforms of the whole 18, and a coding circuit section 20 for passing only waveforms having a size over a predetermined range at the output of the partial polarity inversion unit 18. ), A third subtraction for calculating the difference between the DC voltage supply unit 21 for applying a reference voltage to the limiter 19 and the coding circuit unit 20, and the outputs of the limiter 19 and the coding circuit unit 20. A smoothing circuit section 23 for smoothing the output of the circuit section 22 and the third subtracting circuit section 22 to adjust gains of the first, second amplifying sections 11, 12, and the first, An adder circuit section 8 for calculating an outline correction signal from the output signals of the second amplifiers 11 and 12, and a switching section 13 for outputting and blocking the output of the adder circuit section 8 to the output terminal 10; And a polarity inversion so that the value of the contour correction signal gain-adjusted by the first amplifier 11 has only a positive value. A level setting section 15 that receives the output of the partial polarity inversion section 14 and generates a DC voltage proportional to the magnitude of the amplitude of the contour correction signal, and the level setting section 15 Comparing unit 16 for turning on / off the switching unit 13 by comparing the output DC voltage value with the contour correction signal calculated by the addition circuit unit (8).

The operation and effects of the present invention configured as described above are described below with reference to FIGS. 6 to 9.

In the circuit having reduced contour correction time according to the present invention, after the video signal input through the input terminal 1 is delayed by a predetermined time time constant τ through the first delay circuit unit 2, the first subtraction circuit unit 3 The contour correction signal is formed by subtracting the signal from the input terminal (1).

Meanwhile, the signal delayed by the time delay τ through the first delay circuit unit 2 is further delayed by the time constant τ through the second delay circuit unit 5, and then, by the second subtraction circuit unit 6. The contour correction signal is formed by subtracting from the output of the first delay circuit section 2.

In this way, the contour correction signal completed through the first and second subtraction circuits 3 and 6 is controlled by the first and second amplification units 11 and 12, and then added by the addition circuit unit 8. It is calculated as one contour correction signal and input to the switching unit 13.

In addition, after a negative value is replaced by a positive value through some polarity inversion unit 14, it is input to the level setting unit 15 to set a reference value at a predetermined level as shown by a dotted line shown in (a) of FIG. 6. .

The reference value set as described above is inputted to the comparator 16 and compared with the existing contour correction signal. Only the contour correction signal having an absolute value larger than the absolute value of the reference level, such as the hatched portion shown in (a) of FIG. 6, is switched. The input to (13) turns on the switching unit 13.

The contour correction signal input to the switching unit 13 by the turn-on of the switch unit 13 outputs a correction signal as shown in FIG.

Therefore, the image signal corrected as shown in (c) of FIG. 6 is output by combining with the image signal delayed by the time constant?.

In the high frequency correction output reinforcement circuit according to the present invention, after the video signal input through the input terminal 1 is delayed for a predetermined time by a time constant τ through the first delay circuit unit 2, the first subtraction circuit unit 3 The contour correction signal is formed by subtracting the signal from the input terminal (1).

In addition, the signal delayed by the time delay τ through the first delay circuit unit 2 is further delayed by the time constant τ through the second delay circuit unit 5, and then, by the second subtraction circuit unit 6. The contour correction signal is formed by subtracting from the output of the first delay circuit section 2.

The contour correction signal thus formed is input to the first and second amplifiers 11 and 12.

On the other hand, the signal delayed by the time constant (τ) through the first delay circuit section 2 is filtered through the high pass filter 17, the high-frequency components through the high-pass filter section through some polarity inverting section 18 A negative value of the output waveform of (7) is converted into a positive value to output a signal having only a positive value as shown in (a) of FIG.

This signal outputs only a waveform having a magnitude within a predetermined range as shown in (b) of FIG. 7 through the limiter 19, and (c) of FIG. 7 through a coding circuit section 20 having characteristics as shown in FIG. Like this, only the waveform with the size over a certain range is outputted.

In this case, the reference voltage is determined by the output of the DC voltage supply unit 21 of the limiter 19 and the coding circuit unit 20. The output of the limiter 19 and the output of the coding circuit unit 20 output as described above are third The output is calculated through the subtraction circuit section 22, and the contour difference signal as shown in (d) of FIG. 7 is output, and smoothed as shown in (e) of FIG. By adjusting the gains of the two amplifiers 11 and 12, the contour correction signal is calculated through the addition circuit section 8, and outputs the correction output with high frequency enhancement to the output terminal 10.

According to another embodiment of the present invention, the video signal input through the input terminal 1 is first and second subtracted after a time delay by the time constant τ through the first and second delay circuit units 2 and 5. The contour correction signal completed through the circuit parts 3 and 6 adjusts its gain appropriately through the first and second amplification parts 11 and 12.

On the other hand, the image signal time-delayed by the time delay τ through the first delay circuit unit 2 passes through the high pass filter unit 17, and only a high frequency component remains, and through some polarity inversion unit 18, Outputs a signal waveform having only the same positive value as (A).

This signal is output as a signal such as (b) and (c) of FIG. 7 through a coding circuit 20 having characteristics similar to those of the limiter 19, with the limiting level and the coding of the limiter 19. FIG. The coding level of the circuit section 20 is given via the DC voltage supply section 21.

The output waveforms of these two circuits are output as a waveform as shown in (d) of FIG. 7 via the third subtraction circuit section 22, and the two subtracted output waveforms are input to the smoothing circuit section 23, as shown in (e) of FIG. Output a smooth waveform.

At this time, the smoothing circuit unit 23 generates an output only for a high frequency component signal having a magnitude within a predetermined range set by the DC voltage supply unit 21, so that the smooth and precise image having a high degree of change in the image signal (e.g., For example, it is used as a control signal to increase the intensity of contour correction.

Therefore, the output voltage of the smoothing circuit section 23 is applied to the first and second amplifying sections 11 and 12 as a gain control circuit.

On the other hand, a part of the contour correction signal that has passed through the polarity inversion unit 14 is input to the level setting unit 15 to generate a DC voltage proportional to the magnitude of the contour correction signal.

This DC voltage is input to the comparator 16 as a reference level and compared with the completed contour correction signal.

For example, if the reference example bell is set to the level indicated by the dotted line for the contour correction signal as shown in FIG. 6A, the comparison unit 16 switches only the contour correction signal having an absolute value greater than the absolute value of the reference level. The control unit 13 generates a control signal to allow passage.

By this control signal, the switching unit 13 is switched to finally output the improved contour correction signal to the output terminal 10 as shown in FIG.

This improved contour correction signal is added to the video signal to generate the contour signal with the outline highlighted as shown in FIG. 6 (c), whereby the time widths of the rising and falling portions of the video signal are adjusted as shown in FIG. You can get a clear picture.

As described in detail above, the present invention can reproduce the image more clearly by adjusting the time width of the contour correction signal proportional to the sharpness of the image signal, and by correcting the contour according to the content of the image information, that is, For monotonous images with little change, the amount of contour correction is suppressed to prevent noise.For fine and precise images with large changes in image signals such as grassy images, the amount of outline correction is increased to make the screen vivid and harmonious. It can be reproduced has the effect of improving the practicality and reliability.

Claims (3)

A first delay circuit section 2 for delaying the video signal input through the input terminal 1 by a time difference τ, a video signal delayed by the first delay circuit section 2, and a signal of the input terminal 1; A first subtraction circuit section 3 for forming a contour correction signal from the second delay circuit section for delaying the output signal delayed by the time constant? Of the first delay circuit section 2 by a time constant? 5), a second subtraction circuit section 6 for forming a contour correction signal from the output signals of the first and second delay circuit sections 2, 5, and the first and second subtraction circuit sections 3, The first and second amplifiers 11 and 12 for amplifying the contour correction signal formed in (6), and the contour correction signal adjusted by the first and second amplifiers 11 and 12 are one. An addition circuit section 8 which completes the correction signal of?, A switching section 13 which outputs and cuts off the output of the addition circuit section 8 to the output terminal 10, and gain control of the first amplifier section 11; Day of contour correction signal A level setting for receiving a part of the polarity inversion unit 14 and the output of this part of the polarity inversion unit 14 so as to have only a positive value with respect to and generating a DC voltage proportional to the magnitude of the amplitude of the contour correction signal. A comparison section 16 which turns on / off the switching section 13 by comparing the section 15 and the DC voltage value output from the level setting section 10 with the contour correction signal calculated by the trailing circuit section 8. Contour correction signal generator, characterized in that consisting of. The first delay circuit unit 2 delays the video signal input through the input terminal 1 by the time difference τ, and the video signal delayed by the first delay circuit unit 2 and the signal of the input terminal 1. A first subtraction circuit section 3 for forming a contour correction signal from the second delay circuit section 5 for further delaying the output signal delayed by the time constant? Of the first delay circuit section 2 by a time constant? ), A second subtraction circuit section 6 for forming a contour correction signal from the output signals of the first and second delay circuits 2 and 5, and the first and second subtraction circuit sections 3, ( First and second amplifiers 1l and 12 for amplifying the contour correction signal formed in 6), and a high pass filter unit 17 for filtering high frequency components from the output signal of the first delay circuit unit 2; And a part of the polarity inversion part 18 which makes the negative value of the output waveform of the high frequency pass filter part 17 a positive value, and the output waveform of this part of the polarity inversion part 18 within a predetermined range. A limiter 19 for passing only waveforms having a size within a predetermined range, a coding circuit unit 20 for passing only waveforms having a size over a predetermined range at an output of the partial polarity inversion unit 18, and the limiter 19 And a DC voltage supply unit 21 for applying a reference voltage to the coding circuit unit 20, a third subtraction circuit unit 22 for calculating a difference between the outputs of the limiter 19 and the coding circuit unit 20, and A smoothing circuit section 23 for smoothing the output of the three subtraction circuit sections 22 to adjust the gains of the first and second amplifying sections 11 and 12, the first and second amplifying sections 11, And an addition circuit section (8) for calculating the contour correction signal from the output signal of (12) and outputting the contour correction signal to the output terminal (10). 3. A switching unit (13) for outputting and interrupting the output of the addition circuit (8) to the output terminal (10), and for a part of the gain-adjusted contour correction signal in the first amplifier (11). A partial polarity inversion part 14 for having the value only a positive value, and a level setting part for receiving the output of the partial polarity inversion part 14 and generating a DC voltage proportional to the magnitude of the amplitude of the contour correction signal ( 15) and a comparator 16 for turning on / off the switching section 13 by comparing the DC voltage value output from the level setting section 15 with the contour correction signal calculated by the addition circuit section 8; Contour correction signal generator characterized by including the configuration.