JP2000217130A - Video signal processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a video signal processor that can prevent deterioration in data of a data broadcast for a vertical blanking period. SOLUTION: A line memory 101 receiving an input composite video signal S101 outputs a 1-line delay composite video signal S102, and a line memory 102 receiving an output of the line memory 101 outputs a 2-line delay composite video signal. A 3-line correlation color separation circuit 106 receiving the video signals S101, S102, S103 separates a color signal S107, and a subtractor 107 obtains a luminance signal. When the correlation between a reference line and a line for a vertical blanking period is low, a selector 108 is switched and the 1-line delay composite video signal is outputted to prevent deterioration in data for the vertical blanking period.

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 apparatus used for processing a video signal.

[0002]

2. Description of the Related Art In recent years, with the increasing functionality of television receivers, data broadcasts have been multiplexed into video signals and transmitted from broadcast stations. Therefore, a video signal processing device that processes a video signal in which a data broadcast is multiplexed is regarded as important. Also, with the increase in the screen size and the width of the television receiver, there is a growing demand for image quality improvement. In the YC separation circuit, the correlation between a plurality of scanning lines is used. Video signal processing devices, such as emphasizing, have been developed.

[0003]

However, in the above-mentioned conventional video signal processing apparatus, the input composite video signal is continuously processed by a YC separation circuit between a plurality of scanning lines or the like, so that the correlation between lines is small. Even when data is multiplexed in the vertical flyback period, there is a problem that the video signal processing is not required and the data is continuously processed, and the data multiplexed in the vertical flyback period is not correctly output. In addition, there is a problem that data is not correctly output by emphasizing a portion having a contour portion of the composite video signal input by the contour portion emphasizing circuit. The present invention is to solve the conventional problems as described above, and in a device that performs special processing of a video part, by not performing special processing of a data broadcast multiplex part, does not deteriorate data multiplexed in that part. It is another object of the present invention to provide a video signal processing device capable of preventing data of an input video signal having a small correlation between vertical blanking periods.

[0004]

According to a first aspect of the present invention, there is provided a video signal processing apparatus which receives a video input signal, performs signal processing, and outputs a first output. Processing means for inputting the video input signal, the first output and the control signal to select the first output during a vertical blanking period and select the video input signal during a period other than the vertical blanking period, Switching means for outputting an output. With the above configuration, even when the signal in the vertical retrace period is a signal that is destroyed by being subjected to signal processing, a correct output signal can be obtained inside and outside the vertical retrace period by the video signal processing device. .

According to a second aspect of the present invention, there is provided a video signal processing apparatus according to the first aspect, wherein the signal processing means has a waveform equivalent to that of the video input signal. 3 is also output, and the selection means inputs the third output instead of the video input signal. According to the above configuration, for example, when the video input signal and the phase of the signal processing unit need to have a predetermined phase relationship, a signal having a desired phase can be obtained from the signal processing unit. In addition, it is not necessary to provide a part having the function outside the signal processing device, that is, the circuit scale can be reduced accordingly.

According to a third aspect of the present invention, there is provided a video signal processing apparatus according to the first or second aspect of the present invention, wherein a video input signal is input to a stage preceding the selecting means. It is provided with control means for generating a control signal by performing synchronization separation. According to the above configuration, it is possible to generate the control signal from the video input signal.

According to a fourth aspect of the present invention, there is provided a video signal processing apparatus according to the first or second aspect of the present invention, wherein a vertical pulse is set as a reset signal before the selecting means. It comprises a counting means for performing a counting operation and outputting a count value, and a decoding means for generating a control signal by decoding the count value. According to the above configuration, the control signal can be generated by a countable signal such as a vertical pulse or a clock.

According to a fifth aspect of the present invention, there is provided a video signal processing apparatus according to the present invention, wherein the signal processing means is a color separation circuit. . With the above configuration, the function and effect of the signal processing device according to claims 1 to 4 can be realized even when the signal processing unit is a color separation circuit.

According to a sixth aspect of the present invention, there is provided a video signal processing apparatus according to the present invention, wherein the signal processing means is a vertical contour correction circuit. is there. According to the above configuration, Claim 1
The functions and effects of the signal processing device described in (4) can be realized even when the signal processing means is a vertical contour correction circuit.

According to a seventh aspect of the present invention, there is provided a video signal processing apparatus according to the present invention, wherein the signal processing means is a horizontal contour correction circuit. is there. According to the above configuration, Claim 1
The functions and effects of the signal processing device described in (4) to (4) can be realized even when the signal processing means is a horizontal contour correction circuit.

According to another aspect of the present invention, there is provided a video signal processing apparatus according to the present invention, wherein a gain is 0 during a vertical blanking period when a video input signal is input, and there is a period other than the vertical blanking period. The apparatus is provided with vertical contour correcting means for performing vertical contour correction with a predetermined gain. With the above configuration, a desired output can be obtained inside and outside the vertical blanking period even when the input video signal in the vertical blanking period is a signal destroyed by the vertical contour correction.

In order to solve the above problem, a video signal processing apparatus according to a ninth aspect of the present invention has a gain of 0 during a vertical blanking period when a video input signal is input, and there is a period other than the vertical blanking period. The apparatus is provided with horizontal contour correction means for performing horizontal contour correction with a predetermined gain. With the above configuration, a desired output can be obtained inside and outside the vertical blanking period even when the input video signal in the vertical blanking period is a signal destroyed by the horizontal contour correction.

[0013]

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

(Embodiment 1) A video signal processing apparatus according to Embodiment 1 of the present invention will be described.

FIG. 1 is a block diagram showing the configuration of the video signal processing apparatus according to the first embodiment. In FIG.
101 and 102 are 1H line memories, 103 to 10
5 is a bandpass filter, 106 is a 3-line correlated color separation circuit, 107 is a subtractor, 108 is a selector, 109
Is a sync separation circuit, and 110 is a luminance output circuit. FIG. 2 is a block diagram showing another configuration example of the luminance output circuit. In FIG. 2, 201 is a logic circuit, and 202 is a subtractor.

An example of the operation of the video signal processing device configured as described above will be described below.

FIG. 3 is a waveform diagram showing an example of a composite video signal input to the video signal processing device according to the first embodiment. FIG. 3 is a waveform transition diagram of each part when explaining the operation of the video signal processing device. is there. FIG. 3A shows an input composite video signal S101, which shows an example of a video signal for three line periods. The nH (reference) line does not carry data broadcasting or data, and the (n-1) H (previous) line and the (n + 1) H (rear) line before and after it have the color subcarrier frequency of 3 This is the case where data broadcasting or data having a frequency component near .58 MHz is carried. In describing the operation, a video signal as shown in FIG. 3A is used, but the same applies if there is no correlation before and after the reference line. FIG. 3B shows a one-line delayed composite video signal S102 obtained by delaying the signal of FIG.
FIG. 3C shows a two-line delayed composite video signal S103 obtained by delaying the signal of FIG. 3B by one line, and FIG. 3D shows the signal of FIG. (N + 1) H video signal S10 band-limited by band-pass filter 103 that passes a band near the frequency
4 and FIG. 3 (e) shows the signal of FIG.
NH video signal S105 band-limited by 04, FIG.
FIG. 3F shows an (n-1) H video signal S106 obtained by band-limiting the signal of FIG.
(g) is a color signal S10 separated by seeing the correlation between the three lines.
7, FIG. 3 (h) is a subtractor output signal S108, and FIG.
This is a luminance output signal S110 in which data does not deteriorate when the input signal of (a) is input. From the composite video signal S101 shown in FIG.
To obtain a one-line delayed composite video signal S102 delayed by one line period, and further obtains a two-line delayed composite video signal S103 delayed by one line period by the line memory 102. These are based on the one-line delayed composite video signal S102, and the composite video signal S10 of the (n-1) H line of the preceding and following lines is used.
1 and (n + 1) H line composite video signal S10
3 and 3 make it possible to calculate a video signal between three lines. Then, the input composite video signal S101 is band-limited by the bandpass filter 103 centered on the color subcarrier frequency, and the (n + 1) H video signal S1 is band-limited.
04, similarly a one-line delayed composite video signal S10
2 is an nH video signal S10 band-limited by a band-pass filter 104 centered on the color subcarrier frequency.
The 5 and 2 line delay composite video signal S103 is a bandpass filter 1 centered on the color subcarrier frequency.
(N-1) H video signal S10 band-limited by F.05
6 are obtained. These (n + 1) H video signals S1
04, nH video signal S105, (n-1) H video signal S
106 is input to the three-line correlated color separation circuit 106,
The color signal S107 is separated from the color components between the three lines by majority decision according to the degree of correlation between the lines. For example,
As shown in FIG. 3, (n-1) H video signals S106 and (n)
+1) If the H video signal S104 has a correlation but the nH video signal has no video, there should be no data on the reference line by the three-line correlated color separation circuit 106.
The (n-1) H video signal S106 and the (n + 1) H video signal S104 having a large correlation number like the nH line in (g) are separated as a color signal S107. Then, the separated color signal S107 is subtracted from the one-line delayed composite video signal S102 by the subtractor 107 to obtain the signal shown in FIG.
A luminance signal S108 like the nH line shown in (h) is obtained. As shown in FIG. 3 (h), the data signal is not originally multiplexed on the nH (reference) line, but a circuit for separating the luminance signal and the chrominance signal based on the correlation between the three lines. Computing with a circuit would rather degrade data. Therefore, a switching signal S109 is output from a sync separation circuit 109 capable of separating a vertical sync signal from the input composite video signal S101, and the obtained luminance signal S108 and one-line composite video signal S102 indicate a vertical blanking period. Switching signal S109
The luminance output signal S110 is obtained by switching with the selector 108. If there is no selector 108,
In other words, the nH video signal serving as a reference between the three lines becomes a luminance signal S108 even though it has no frequency component, and changes data in the vertical blanking period. However, the selector 108 is switched by a switching signal S109 indicating an arbitrary period of the vertical blanking period, and the one-line delay composite video signal S102 is converted to the luminance output signal S1 for the period in which the data broadcasting is multiplexed.
By outputting as it is as 10, it is possible to prevent deterioration. Here, the case where the line memory is delayed by one line period has been described, but the same holds true when the line memory is delayed by two lines or three lines. Further, although the luminance output circuit 110 is configured by a selector, a similar result can be obtained by the configuration as shown in FIG. In FIG. 2, the same signals as those in FIG. The output of the logic circuit 201 can be fixed to 0 during the period in which the data broadcast of the vertical baseline period is multiplexed by the switching signal S109, so that the one-line delayed composite signal S102 is not subtracted by the subtracter 202, and the luminance output is performed. Output as signal S110.

According to this embodiment, when data broadcasting is multiplexed during the vertical flyback period, the synchronization separation circuit 109
By outputting the input composite video signal as a luminance signal as it is in an arbitrary period of the vertical blanking period according to the switching signal S109 output from the, the deterioration of data in the vertical blanking period can be prevented.

(Embodiment 2) A video signal processing apparatus according to Embodiment 2 of the present invention will be described.

FIG. 4 is a block diagram showing the configuration of the video signal processing apparatus according to the second embodiment. In FIG.
Reference numerals 101 to 110 correspond to the same reference numerals shown in FIG. 401 is a counter circuit, and 402 is a decode circuit for decoding a counter value. Also,
FIG. 5 is an example of a timing chart used to describe the counter circuit 401 and the decode circuit 402. In FIG. 5, the counter value is counted up on the basis of the vertical pulse of the input video signal, and a certain necessary range is decoded so that the data broadcast area can be switched.

An example of the operation of the video signal processing device configured as described above will be described below.

Using the input vertical pulse S401 as a reset signal, the counter circuit 401 capable of counting up the horizontal synchronization pulse S404 counts every 1H line period. By decoding the necessary part of the count value S402 by the decode circuit 402, a switching signal S403 capable of distinguishing the data broadcasting area is created. As described in the first embodiment, the luminance signal S10
The 8 and 1 line delay composite video signal S102 is switched by the selector 108 according to the switching signal S403 output from the decoding circuit 402, and the luminance output signal S110 is switched.
Get.

According to this embodiment, the data broadcast is multiplexed during the vertical flyback period by the configuration including the three-line correlated color separation circuit 106, the subtracter 107, the selector 108, the counter circuit 401, and the decode circuit 402. By outputting the input composite video signal as a luminance signal during the period, it is possible to prevent data deterioration during the vertical blanking period.

In the above description, the counter circuit 401
Has been described in the example of counting the horizontal synchronization pulses, but the same can be implemented by counting clocks.

(Embodiment 3) A video signal processing apparatus according to Embodiment 3 of the present invention will be described.

FIG. 6 is a block diagram showing the configuration of the video signal processing apparatus according to the third embodiment. In FIG.
Reference numerals 101 and 102 correspond to the same reference numerals shown in FIG. Reference numeral 601 denotes a vertical contour correction circuit that emphasizes a portion that changes in the vertical direction, and 602 denotes a selector circuit. FIG. 8A is an input waveform diagram of an example of an input composite video signal, and FIG. 8B is an output waveform diagram having passed through the vertical contour correction circuit 601.

An example of the operation of the video signal processing device configured as described above will be described below.

Assuming that the input waveform shown in FIG. 8A is input from the input composite video signal S101, the one-line delayed composite video signal S102 delayed by one line period by the line memory 101 and the one-line delayed A delayed two-line delayed composite video signal S103 is obtained. These are input to the vertical contour correction circuit 601 to obtain an enhanced contour corrected luminance signal S601 by attaching a shot or the like so as to emphasize the vertical contour of the screen. In the example of FIG. 8A, the (n−1) H period, the nH period, and the (n + 1) H period are all above the data slice level, but the vertical contour correction circuit 601 uses the (n−1) H period. Signal and (n + 1) H
The signal of the period becomes brighter (to the white side) with a larger amplitude. Then, the signal in the nH period is darkened (to the black side) by reducing its amplitude, and the edge portion that changes in the vertical direction is emphasized, thereby sharpening the edge portion signal. By correcting to the white side and the black side, respectively, when it is near the slice level like the nH period in FIG.
In FIG. 8A, although the data is above the slice level, the data is changed because the vertical contour correction circuit 601 corrects the data below the slice level in FIG. 8B. Was. This contour correction luminance signal S6
01 and the one-line delay composite video signal S102 are input to the selector 602, and the switching signal S109 that is switched at any time during the vertical blanking period causes the one-line delay composite video signal S102 to be generated at any time during the vertical blanking period. Is output as the luminance signal S602.

According to this embodiment, when data broadcasting is multiplexed during the vertical blanking period, the input composite video signal is output as it is as a luminance signal during an arbitrary period of the vertical blanking period, so that the vertical blanking period is obtained. Data deterioration during the line period can be prevented. The vertical contour correction circuit 601
Can be configured to directly output a video input signal by setting the gain to zero. In this case, the signal is processed by setting the gain to 0 during the vertical retrace period, and the signal is processed by setting the gain to a certain value during periods other than the vertical retrace period.
A similar effect can be obtained without using.

(Embodiment 4) A video signal processing apparatus according to Embodiment 4 of the present invention will be described.

FIG. 7 is a block diagram showing the configuration of the video signal processing apparatus according to the fourth embodiment. In FIG.
701 is a horizontal contour correction circuit, and 702 is a selector.

An example of the operation of the video signal processing device configured as described above will be described below.

When the input waveform is input from the input luminance signal S101 to the horizontal contour correction circuit 701, the horizontal contour correction circuit 701 corrects the image by adding a shot or the like so as to emphasize the horizontal contour of the screen, or corrects the inclination. Is obtained as if the horizontal contour correction luminance signal S701 is sharp. The contour correction luminance signal S701 and the input luminance signal S101 are input to the selector 702, and the input luminance signal S101 is switched for an arbitrary period of the vertical retrace period by a switching signal S109 that is switched in an arbitrary period of the vertical retrace period. The output luminance signal S702 is obtained.

According to this embodiment, when data broadcasting is multiplexed during the vertical retrace period, the input luminance signal is output as a luminance signal during an arbitrary period of the vertical retrace period, whereby the vertical retrace period is reduced. Can be prevented from deteriorating.

The horizontal contour correction circuit 701 sets the gain to 0.
By doing so, it is also possible to adopt a configuration in which a video input signal is directly output. In this case, the same effect can be obtained without using the selector 702 by performing signal processing with the gain set to 0 during the vertical retrace period and signal processing with the gain set to a certain value during periods other than the vertical retrace period. is there.

[0036]

As described above, according to the video signal processing apparatus of the present invention, an arbitrary vertical blanking period for the luminance signal output from the YC separation circuit is switched to the input video signal, thereby achieving the vertical Data degradation of the input video signal during the flyback period can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a video signal processing device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating an example of a luminance output circuit of the video signal processing device according to the first embodiment of the present invention.

FIG. 3 is a waveform diagram of each part when processing an example of an input video signal according to the first embodiment of the present invention;

FIG. 4 is a block diagram showing a configuration of a video signal processing device according to a second embodiment of the present invention.

FIG. 5 is a timing chart of the video signal processing device according to the second embodiment of the present invention;

FIG. 6 is a block diagram showing a configuration of a video signal processing device according to a third embodiment of the present invention.

FIG. 7 is a block diagram showing a configuration of a video signal processing device according to a fourth embodiment of the present invention.

FIG. 8 is an input / output waveform diagram of a vertical contour correction circuit of the video signal processing device according to the third embodiment of the present invention.

[Explanation of symbols]

 101 line memory 102 line memory 103 band pass filter 104 band pass filter 105 band pass filter 106 3 line correlated color separation circuit 107 subtractor 108 selector 109 sync separation circuit 110 luminance output circuit 201 logic circuit 202 subtractor 401 counter circuit 402 decoding times 601 Vertical contour correction circuit 602 selector 701 Horizontal contour correction circuit 702 selector

Claims (9)

[Claims] 1. A signal processing means for receiving a video input signal, performing signal processing and outputting a first output, and receiving the video input signal, the first output, and a control signal to receive a vertical blanking period Switching means for selecting the first output, and selecting the video input signal and outputting a second output during a vertical flyback period. 2. The video signal processing apparatus according to claim 1, wherein the signal processing means has a third waveform having a waveform equivalent to the video input signal.
A video signal processing device, wherein the selecting means inputs the third output instead of the video input signal. 3. The video signal processing apparatus according to claim 1, further comprising a control means for generating a control signal by inputting a video input signal and performing synchronization separation at a stage preceding the selection means. Video signal processing device. 4. The video signal processing apparatus according to claim 1, wherein a count means for performing a count operation using a vertical pulse as a reset signal and outputting a count value is provided before the selection means, and decoding the count value. And a decoding means for generating a control signal according to (1). 5. The video signal processing device according to claim 1, wherein the signal processing means is a color separation circuit. 6. The video signal processing device according to claim 1, wherein the signal processing means is a vertical contour correction circuit. 7. The video signal processing device according to claim 1, wherein the signal processing means is a horizontal contour correction circuit. 8. An image which is provided with a vertical contour correcting means which receives a video input signal, has a gain of 0 during a vertical blanking period, and performs vertical contour correction with a predetermined gain other than during the vertical blanking period. Signal processing device. 9. A horizontal contour correcting means for inputting a video input signal and having a gain of 0 during a vertical blanking period and performing horizontal contour correction with a predetermined gain except for the vertical blanking period. Video signal processing device.