JPH07184233A - Video signal processor - Google Patents

Abstract

PURPOSE:To provide the high performance video signal processor by which a residual chroma component in a luminance signal is surely eliminated. CONSTITUTION:An inputted luminance signal is delayed by 1H at a delay circuit 2, the delayed signal is amplified by an amplifier 3 and subtracted from the original signal at a subtractor 4 and then a residual chroma component is extracted. The extracted residual chroma component is fed respectively to a comparator 5 and a switch 6, the comparator 5 detects the signal level of the residual chroma component and outputs a control signal used to switch the switch 6 when the level reaches a predetermined value or over. When the residual chroma component is in existence, the switch 6 turned ON and when not in existence, the switch 6 turned OFF. When the switch 6 in turned ON, a subtractor 7 eliminates the residual chroma component from the original luminance signal and outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a video signal processing device for improving the image quality of video.

[0002]

2. Description of the Related Art When a video signal is recorded, a chroma component remains in the luminance signal because the characteristic phase and gain of a comb-type filter for separating the color signal and the luminance signal do not match properly. However, when reproduction is performed in this state, the residual chroma component in the luminance signal accompanied by phase fluctuation due to jitter interferes with the chroma signal whose phase is fixed, and a beat is generated. In the past, in order to prevent this beat, the reproduced luminance signal was passed through the comb filter again to remove the residual chroma component. For this reason, the filter is always fixed in the operating state, or the user has to arbitrarily set ON / OFF with a switch or the like.

[0003]

However, in the above-mentioned conventional example, the beat generated by removing the residual chroma component in the reproduction luminance signal is improved, but the beat-type filter of the comb-type filter does not depend on the amount of the residual chroma component. ON / O operation
In order to perform FF, the comb-type filter is operated unnecessarily to cause deterioration of the resolution of the Y signal in the diagonal direction,
On the contrary, there was a case where a beat was generated without operating when necessary.

Since the amount of residual chroma signal generated mainly depends on the Y / C separation characteristics during recording, it is difficult to determine ON / OFF of the filter operation in advance. It was a big issue for improvement.

[0005]

The present invention has been made in order to solve the above-mentioned problems, and is characterized by an extracting means for extracting a chroma component in a luminance signal in a video signal processing device. And a correction unit that corrects the luminance signal using the chroma component, and a control unit that adaptively operates the correction unit according to the chroma component extracted by the extraction unit. To do.

[0006]

Embodiments of the present invention will be described below with reference to the drawings.

<< Embodiment 1 >> FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention. In FIG. 1, the luminance signal input from the input terminal 1 is delayed by the delay circuit 2 for 1H time, amplified by the amplifier 3, and then subtracted from the original signal by the subtractor 4. Then, the subtractor 4 outputs the residual chroma component in the reproduced luminance signal.

The residual chroma component output from the subtractor 4 is supplied to the comparator 5 and the switch 6, respectively. The comparator 5 detects the signal level of the residual chroma component and outputs a control signal for switching the switch 6 when the level exceeds a certain value.

The switch 6 is turned on by the control signal output from the comparator 5 when the residual chroma component is present, and is turned off when the residual chroma component is not present. When the switch 6 is ON, the residual chroma component is input to the subtractor 7 and subtracted from the original signal to remove the residual chroma signal from the luminance signal and output from the output terminal 8.

With the above-mentioned structure, the Y-comb filter is turned off by the switch 5 when the residual chroma component is small, so that the deterioration of the luminance signal can be prevented. Needless to say, the chroma component may be extracted by means other than the comb filter.

<Embodiment 2> FIG. 2 is a block diagram showing the configuration of Embodiment 2 of the present invention. In FIG. 2, the luminance signal input from the input terminal 9 is delayed by 1H time in the delay circuit 10, amplified in the amplifier 11, and then subtracted from the original signal in the subtractor 12. Then, the subtractor 12 outputs the residual chroma component in the luminance signal.

The residual chroma component output from the subtractor 12 is supplied to the comparator 13, which detects the signal level of the residual chroma component and controls the amplifier 11 in accordance with the level to amplify the signal amplification amount. By changing it, more effective extraction of residual chroma components is performed. The residual chroma component thus extracted is subtracted from the original signal by the subtractor 14 to remove the residual chroma signal from the luminance signal, and output from the output terminal 15.

As described above, by changing the characteristics of the comb filter in accordance with the amount of the residual chroma signal in the luminance signal, the residual chroma component can be removed reliably and effectively.

[0014]

As described above, the extracting means for extracting the chroma component in the luminance signal, the correcting means for correcting the luminance signal by using the chroma component, and the correcting means adapted according to the extracted chroma component. In order to operate the extraction means as necessary, the control means for automatically operating the extraction means is provided.
The overall effect of image quality improvement was obtained, and the operation was simplified.

[Brief description of drawings]

FIG. 1 is a configuration block diagram of a first embodiment of the present invention.

FIG. 2 is a configuration block diagram of a second embodiment of the present invention.

[Explanation of symbols]

 2,9 Delay circuit 3,11 Amplifier 5,13 Comparator

Claims (2)

[Claims] 1. Extraction means for extracting a chroma component in a luminance signal, correction means for correcting the luminance signal using the chroma component, and the correction means according to the chroma component extracted by the extraction means. And a control means for adaptively operating the video signal processing apparatus. 2. Extracting means for extracting a chroma component in a luminance signal, detecting means for detecting the amount of the chroma component, and characteristics of the extracting means according to the amount of the chroma component detected by the detecting means. And a control means for controlling the video signal processing device.