JP3454083B2 - Conveyor color signal contour correction device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carrier color signal contour correction device for sharply correcting a color change portion of a carrier color signal of a video signal.

[0002]

2. Description of the Related Art In recent years, as a carrier color signal contour correction device, one described in Japanese Patent Laid-Open No. 4-196666 has been known.

FIG. 3 shows a block diagram of a conventional carrier color signal contour correction device. In FIG. 3, reference numeral 20 is a phase detection circuit, 40 is a delay device, 30 is an amplitude detection circuit, 50 is an edge correction circuit, 60 is a multiplier, and 70 is an output terminal.

The operation of the conventional carrier color signal contour correcting device configured as described above will be described below. In the conventional example, first, the carrier color signal is input, and the phase information signal obtained from the phase detection circuit 20 represents the hue and is supplied to the multiplier 60 via the delay device 40 for time adjustment. The phase information signal is a sine wave signal whose amplitude is constant and which is phase-modulated. On the other hand, the amplitude detection circuit 30 detects the amplitude (color saturation) regardless of the hue and detects the amplitude information as the edge correction circuit 50. Supply to. Then, in the edge correction circuit 50, the high frequency component of the amplitude change (edge correction signal)
The contour-corrected color amplitude signal is input to the multiplier 60 by taking out the gain and adding it to the original amplitude information. As a result, the output terminal 70 is configured so as to obtain the carrier color signal in which the hue change of the carrier color signal is kept as it is and the saturation change is sharp.

[0005]

In the conventional carrier color signal contour correcting apparatus, since the carrier color signal is separated into the phase information and the amplitude information for processing, a very complicated process is required. And there is a demand for improvement on this problem.

[0006]

In order to solve this problem, the present invention does not separate the carrier color signal into phase and amplitude information, but directly processes the carrier color signal so that the edge portion rises and rises. It is configured so that the downtime is short and is corrected sharply.

As a result, the processing can be simplified and stabilized, and the cost can be reduced.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is a first-order differential signal obtained by first-order differentiating an inputted carrier color signal.
And the first derivative signal is delayed for a certain time.
Step, first derivative signal and delayed first derivative signal
The maximum and minimum values of the signal are detected, and a narrow first-order differential signal is generated.
And the first-order differentiation of the narrow first-order differentiation signal
To generate a second derivative signal and a narrow first-order differential signal.
Full-wave rectifying the split signal, the second derivative signal, and
Detects the minimum value of the first-order differential signal with full-wave rectification and narrow width
The step of generating a narrow second derivative signal,
Gain control step for narrow second derivative signal
And a narrow second derivative signal with gain control
Add the input carrier color signal with a delayed signal for a certain time
Carrier color signal characterized by comprising a step of calculating
This is a contour correction method, and has an effect of directly processing a carrier color signal and performing correction so that a color change portion becomes sharp.

Next, a second aspect of the present invention includes a first delay circuit for delaying the carrier color signal input, and a first subtractor circuit for subtracting the output of the first delay circuit from the carrier color signal input. ,
The second delay circuit that further delays the output of the first subtraction circuit is compared with the output of the first subtraction circuit and the output of the second delay circuit. The minimum / maximum value circuit that outputs the one having a larger value on the minus side of the carrier color signal, the third delay circuit that further delays the output of this minimum / maximum value circuit, and the minimum / maximum value circuit A second subtraction circuit for subtracting the output of the third delay circuit from the output, a full-wave rectification circuit for full-wave rectifying the output of the minimum / maximum value circuit, an output of the second subtraction circuit, and a full-wave rectification circuit When the output of the second subtraction circuit is the + side, the smaller value is output, and when the output of the second subtraction circuit is the-side, the absolute value and the output of the full-wave rectification circuit are output. The minimum value circuit that compares and selects the smaller value and sets the polarity to the-side and then outputs this minimum value A gain control circuit for gain-controlling the output of the path according to a preset correction amount, a fourth delay circuit for delaying the carrier color signal input and matching the timing with the correction signal, and an output of the fourth delay circuit. The carrier color signal contour correction device is provided with an adder circuit for adding the output of the gain control circuit and the output of the gain control circuit, and the carrier color signal can be directly processed to perform correction so that the color change portion becomes sharp. Has the effect of.

(Embodiment) A carrier color signal contour correcting apparatus according to an embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

FIG. 1 is a block diagram of a carrier color signal contour correction device according to an embodiment of the present invention, and FIG.
The waveform diagram of each block shown in FIG. 1 is shown. In FIG.
Reference numeral 1 is a first delay circuit, 2 is a first subtraction circuit, 3 is a second delay circuit, 4 is a minimum / maximum value circuit, 5 is a third delay circuit, 6 is a second subtraction circuit, 7 Is a full-wave rectification circuit, 8 is a minimum value circuit, 9 is a fourth delay circuit, 10 is a gain control circuit, and 11 is an addition circuit.

In FIG. 1, the carrier color signal input a is input to the first delay circuit 1 and becomes the delayed carrier color signal input j.
The delay time of the first delay circuit 1 is selected to be an integral multiple of twice the cycle of the normal carrier color signal (280 nsec for NTSC). Here, it is doubled. In the first subtraction circuit 2, the carrier color signal input a to the delayed carrier color signal input j
Is subtracted to obtain the primary differential signal b. This primary differential signal b
Is input to the second delay circuit 3. The delay time of the second delay circuit 3 is the same as that of the first delay circuit 1. The minimum / maximum value circuit 4 receives the primary differential signal b and the delayed primary differential signal k as input, and when the polarities of the primary differential signal b and the delayed primary differential signal k are positive, as shown in FIG. Outputs the smaller value, outputs the larger value when the polarity is negative, and outputs zero when the signal b and the signal k have different polarities. As a result, the corrected primary differential signal c, which is a thin primary differential signal, is obtained. The corrected first derivative signal c is input to the third delay circuit 5 and delayed. The delay time at this time is selected to be half the delay time of the first and second delay circuits. The corrected primary differential signal c delayed by the third delay circuit 5 is output as the delayed corrected primary differential signal l.

The second subtraction circuit 6 subtracts the delayed correction primary differential signal l from the corrected primary differential signal c to produce a secondary differential signal d. The corrected primary differential signal c is input to the full-wave rectifying circuit 7 and full-wave rectified, and the rectified primary differential signal e having only positive polarity is output. Next, the minimum value circuit 8 receives the secondary differential signal d and the rectified primary differential signal e as input, and the secondary differential signal d is +
When it is on the negative side, the smaller one of the signals d and e is output. When the secondary differential signal d is on the negative side, its absolute value and rectification 1
The second differential signal e is compared, the smaller one of the signals d and e is selected, the polarity is set to the negative side, and then the corrected second differential signal f is output. The gain control circuit 10 multiplies the corrected secondary differential signal f by a preset correction amount m and outputs a corrected signal g. The adder circuit 11 adds the correction signal g to the delayed carrier color signal h to obtain the carrier color signal output i in which the color contour portion is sharply corrected.

[0014]

As described above, according to the present invention, the carrier color signal is directly processed without separating the carrier color signal into phase and amplitude information, and the rising and falling times of the edge portion are short and steep. The advantageous effect that it can be corrected is obtained.

[Brief description of drawings]

FIG. 1 is a block configuration diagram of a carrier color signal contour correction device according to an embodiment of the present invention.

FIG. 2 is a waveform diagram of each part in FIG.

FIG. 3 is a block configuration diagram of a conventional carrier color signal contour correction device.

[Explanation of symbols]

1 First delay circuit 2 First subtraction circuit 3 Second delay circuit 4 min / max circuit 5 Third delay circuit 6 Second subtraction circuit 7 Full wave rectification circuit 8 minimum value circuit 9 Fourth delay circuit 10 Gain control circuit 11 adder circuit

─────────────────────────────────────────────────── --- Continuation of the front page (56) References JP-A-2-94873 (JP, A) JP-A-52-68315 (JP, A) JP-A-4-317294 (JP, A) JP-A-4- 196699 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H04N 9/68 103

Claims (2)

(57) [Claims] 1. A first-order differentiation of an input carrier color signal to obtain 1
Generating a second derivative signal, and
Delaying for a certain period of time,
The maximum and minimum values of the delayed first derivative signal are detected, and the width
Generating a first-order differential signal of
Generate a second derivative signal by first differentiating the first derivative signal
Step, full-wave rectifying the narrow first-order differential signal
Step, the second derivative signal and the full-wave rectified width
, The minimum value of the first derivative signal of
Generating a differential signal and the narrow second derivative
Gain control of the signal, and the gain
Controlled narrow second derivative signal and the input
The generated carrier color signal with a signal delayed for a certain period of time
Complementary carrier color signal contour characterized by including steps
Positive way. 2. A first delay circuit for delaying a carrier color signal input, a first subtractor circuit for subtracting an output of the first delay circuit from the carrier color signal input, and a first subtractor circuit of the first subtractor circuit. A second delay circuit that further delays the output is compared with the output of the first subtraction circuit and the output of the second delay circuit, and when the carrier color signal is on the + side, the smaller value is output and the carrier color signal is output. The minimum / maximum value circuit that outputs the larger value on the negative side, the third delay circuit that further delays the output of this minimum / maximum value circuit, and the output of the minimum / maximum value circuit to the third Second subtraction circuit for subtracting the output of the delay circuit, a full-wave rectification circuit for full-wave rectifying the output of the minimum / maximum value circuit, an output of the second subtraction circuit and an output of the full-wave rectification circuit When the output of the second subtraction circuit is +, the smaller value is output. When the output of the second subtraction circuit is on the-side, the absolute value is compared with the output of the full-wave rectifier circuit, the smaller value is selected, and the polarity is set to the-side, then the minimum value is output. A circuit, a gain control circuit for gain-controlling the output of the minimum value circuit in accordance with a preset correction amount, a fourth delay circuit for delaying the carrier color signal input and adjusting the timing with the correction signal, and 4. A carrier color signal contour correction device provided with an adder circuit for adding the output of the delay circuit 4 and the output of the gain control circuit.