JPH02256389A - Video signal processor - Google Patents

Abstract

PURPOSE:To avoid crosstalk disturbance by detecting a nonstandard signal whose chrominance subcarrier and horizontal and vertical scanning frequencies are not in a specific relation from an inputted video signal, applying Y/C separation to the input signal and applying notch filter to the separated luminance signal. CONSTITUTION:A nonstandard signal is detected, in which a chrominance subcarrier and horizontal and vertical scanning frequencies are not in a specific relation and a notch filter 10 is applied to a luminance signal subject to Y/C separation in response to the result of detection. Thus, a signal without dot disturbance is detected to switch the frequency characteristic of a band pass filter 8 extracting a color signal component thereby detecting a signal without cross color disturbance. Thus, a color signal and a luminance signal without crosstalk disturbance are reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention is directed to a color television receiver equipped with a motion adaptive Y/C separation function, in which a reproduction signal of a home VTR or an optical signal of an input color television signal is used. A video signal processing device that detects a non-standard state that does not satisfy the NTSC standard, such as a special reproduction signal of VDP, and reproduces a signal free from crosstalk interference due to interference between luminance signals and color signals.

BACKGROUND OF THE INVENTION In recent years, in color television receivers, image quality deterioration such as dot interference and cross color interference due to the increment of color signals into luminance signals, line flicker due to increment scanning, and reduction in vertical resolution has been reported. In order to almost completely eliminate this, image quality has been improved using frame memory and digital signal processing technology. For example, Nikkei Electronics, July 1, 1985, which introduces processing technologies such as motion-adaptive three-dimensional Y/C separation and progressive scan conversion that utilize the correlation of video signals in the time axis direction.
It is described on pages 195-218 of the Japanese issue.

However, in these high-quality image processing, the input television signal is completely compliant with standards such as NTSC.
That is, color subcarrier frequency fscl horizontal scanning frequency f1
．． , vertical scanning frequency I, are assumed to be signals having a predetermined frequency relationship (hereinafter referred to as standard signals). When motion adaptive processing is performed when the fH2 vertical scanning frequency fv is a signal that does not have a predetermined frequency relationship (hereinafter referred to as a non-standard signal), there is a problem in that the image quality further deteriorates.

In other words, in the standard signal, f, c= f□ (1
)1, = Jv ・・・・・・(
2) fsc' Color subcarrier frequency fo' Horizontal scanning frequency jv: There is a relationship called vertical scanning frequency, and the phase of the color subcarrier is in the opposite phase between frames, so in the case of a still image, the frequency between frames A frame comb filter can be realized that separates the luminance signal and color signal from the sum and difference. On the other hand, in the case of non-standard signals (1
), since there is no relationship in Equation (2), it is not possible to separate frames (using a comb filter) even in still images, and processing suitable for non-standard signals, such as forcing a line comb filter regardless of whether it is a still image or a video, is applied. In order to achieve signal processing with less interference for non-standard signals, it is necessary to detect the non-standard state of the input color television signal. A video signal processing device has been proposed in which a chrominance signal and a luminance signal are forcibly separated using a line comb filter in accordance with the non-standard signal received.

An example of the above-mentioned conventional video signal processing device will be described below with reference to the drawings.

FIG. 6 shows a block diagram of a conventional video signal detection device. In FIG. 6, 101 is an input terminal, 10
2 is a frame comb filter, 103 is a line comb filter, 104 is a motion detection circuit, 105 is a non-standard signal detection circuit, 106 is an OR circuit, 107 is a switching circuit, 10
B is a band pass filter, 109 is a subtracter, 110,1
11 is an output terminal.

In FIG. 6, color signal components of a color television signal supplied to an input terminal 101 are extracted by a frame comb filter 102 and a line comb filter 103. Also,
The color television signal supplied to the input terminal 101 is detected by a motion detection circuit 104 and a non-standard signal detection circuit 105 to determine whether or not there is movement in the input color television signal.
If there is movement due to a non-standard state, the output of the motion detection circuit 104 will be 1"; if the signal is a non-standard signal,
The output of the non-standard signal detection circuit 105 is "1". Furthermore, the motion detection circuit 104゜non-standard signal detection circuit 10
The output of 5 is input to the OR circuit 106, and the output of the OR circuit 10
When the output of 6 is "φ", the frame comb filter 10
2, the output of the OR circuit 106 is “1”.
'', the color signal component is extracted by the line comb filter 103 by the switching circuit 107, and after passing through the band pass filter 108, the color television signal is supplied to the subtracter 109 and the input terminal 101. A luminance signal is obtained at the output terminal 110.

In addition, after passing through the band pass filter 10B, the output terminal 1
11, a color signal is obtained.

Problems to be Solved by the Invention However, in the above configuration, when the input color television signal is in a non-standard state, even if the non-standard signal is stably detected, the non-standard signal is Frequency fsc, horizontal scanning frequency iH = vertical scanning frequency! ,
Since they do not have a predetermined frequency relationship, the chrominance signal and luminance signal cannot be completely separated, resulting in the problem of crosstalk interference.

In view of the above problems, the present invention provides a color subcarrier frequency fs
c horizontal scanning frequency I)1. To provide a video signal processing device that detects a non-standard signal whose vertical scanning frequency jv does not have a predetermined frequency relationship, and reproduces a color signal and a luminance signal without crosstalk interference according to the detected non-standard signal. It is.

Means for Solving the Problems In order to solve the above problems, the video signal processing device of the present invention detects a non-standard signal in which the color subcarrier and the horizontal and vertical scanning frequencies do not have a specific relationship from the input video signal. The apparatus comprises a first means and a second means for Y/C separating the input signal and applying a notch filter to the separated luminance signal in accordance with the first means.

The video signal processing device of the present invention also includes a first means for detecting a non-standard signal in which the color subcarrier and the horizontal and vertical scanning frequencies do not have a specific relationship from the input video signal; A second means applies a notch filter to the separated luminance signal according to the first means; and a frequency characteristic of the bandpass filter to the separated color signal according to the first means. and a third means for switching.

Effect of the Invention The present invention has the above-described configuration, and in a color television receiver equipped with a motion-adaptive Y/C separation function, a reproduction signal of a home VTR or a special reproduction signal of an optical VDP can be reproduced by a non-compliant device that does not satisfy the NTSC standard. The frequency of the bandpass filter that detects the standard state and applies a notch filter to the Y/C separated luminance signal according to the detection result to detect a signal without dot interference and extract the color signal component. By switching the characteristics, a signal without cross color interference can be detected.

Embodiment Hereinafter, a video signal processing apparatus according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a video signal processing device in an embodiment of the present invention. In the figure, 1 is an input terminal, 2 is a frame comb filter, 3 is a line comb filter, 4 is a motion detection circuit, and 5 is a non-standard signal detection circuit 6.
1 is an OR circuit, 7 is a switching circuit, 8 is a band pass filter, 9 is a subtracter, 10 is a notch filter, 11 is a switching circuit, and 12 and 13 are output terminals.

In FIG. 1, the video signal supplied to the input terminal l is supplied to a frame comb filter 2, a line comb filter 3, a motion detection circuit 4, a non-standard signal detection circuit 5, and a subtracter 9, respectively. . The output of the motion detection circuit 4 is "1" when there is movement in the input video signal, and "φ" when it is stationary, and is input to the OR circuit 6. Furthermore, the output of the non-standard signal detection circuit 5 is "1" when the input video signal is in a non-standard state.
” is output, and when it is in the standard state, “φ” is output and input to the OR circuit 6 and changeover switch 11. When , the output of the line comb filter 3 and the output of the frame comb filter 2 when the input video signal is in a static and standard state are supplied to the bandpass filter 8, and the output is used as a color signal. The output of the subtracter 9 is supplied to the subtracter 9 and the output terminal 13.The output of the subtracter 9 is also supplied to the notch filter 10, and the output of the non-standard signal detection circuit 5 is
When the output of the notch filter 10 is the output "φ" of the non-standard signal detection circuit 5, the output of the subtracter 9 is supplied to the output terminal 12 as a luminance signal without dot interference. The non-standard detection circuit 5 can be realized, for example, by a circuit as shown in FIG. 3. In FIG. 3, 51 is an input terminal, 52 is a 1-frame capacity frame memory, 53 is an adder, and 54 is a burst component for extracting burst components. gate, 55 is an absolute value circuit, 56 is a ripple correction circuit, 57 is a comparator that compares the input signal with a predetermined reference value, 58 is a counting circuit that counts the number of data occurrences in an arbitrary period, 59 60 is a determination circuit that verifies a non-standard state in which the color subcarrier of the input signal and the horizontal and vertical scanning frequencies are not in a specific relationship based on the counting results; 60 is an output terminal; In FIG. 3, a video signal supplied to an input terminal 51 is supplied to a frame memory 52 having a capacity of one frame, and its output is supplied to an adder 53 together with the input signal. The one-frame sum signal output from the adder 53 is supplied to a burst gate 54, which extracts the burst component, passes through an absolute value circuit 55, and is supplied to a ripple correction circuit 56 which removes ripple components. The output signal of the ripple correction circuit 56 is input to a comparator 57,
Comparison is made with a predetermined standard value, and if it exceeds the standard value, it is determined to be a non-standard signal and the signal is "1", and if it does not exceed the standard value, it is determined to be a standard signal and the non-standard signal is designated as "φ". The data is output and input to the counting circuit 58.

The count value which is the output from the counting circuit 58 is sent to the judgment circuit 59.
and compared with a predetermined threshold;
If it exceeds the dark value, and if it does not exceed 1 fl, it outputs "φ" and is supplied to the output terminal 60. Here, in the determination circuit 59, a multi-stage output, for example, a 4-stage output "φ"1"2""3" is outputted as a standard signal φ→3 non-standard signal by comparing it with the threshold value, and is supplied to the output terminal 60. Accordingly, the frequency characteristics of the notch filter 10 described above may be switched to a wide band when the signal is a standard signal and a narrow band when the signal is a non-standard signal, for example, as shown in FIG. 4, according to the switching circuit 11. The line (comb filter 3) may be a band pass filter, or may be adaptively switched between a line comb filter and a band pass filter.

FIG. 2 shows a block diagram of a video signal processing device in an embodiment of the present invention. In the same figure, parts corresponding to those in FIG. 1 are shown with the same symbols, and 20 is a narrowband bandpass filter.

In FIG. 2, the video signal supplied to the input terminal 1 is supplied to a frame comb filter 2, a line comb filter 3, a motion detection circuit 4, a non-standard signal detection circuit 5, and a subtracter 9, respectively. Ru. The motion detection circuit 4 outputs "1" when there is movement in the input video signal, and "φ" when the input video signal is stationary, which is input to the OR circuit 6. Further, the output of the non-standard signal detection circuit 5 is "1" when the input video signal is in the non-standard state, and "φ" is output when the input video signal is in the standard state, and is input to the OR circuit 6 and the changeover switch 11. The output of the OR circuit 6 is determined by the changeover switch 7 when there is movement in the input video signal.
Alternatively, when the input video signal is in a non-standard state, the output of the line comb filter 3 is supplied to the bandpass filter 8, and when the input video signal is in a static state and the standard state, the output of the frame comb filter 2 is supplied to the bandpass filter 8. Subtractor 9 as signal
and is supplied to the bandpass filter 20. The bandpass filter 20 operates according to the output of the non-standard signal detection circuit 5.
As shown in FIG. 5, the frequency characteristics are switched to output a color signal without cross color interference, and the signal is supplied to the output terminal 13. The output of the subtracter 9 is also supplied to a notch filter 10, and when the output of the non-standard signal detection circuit 15 is ``1'' by the changeover switch 11, the output of the notch filter 20 is changed to the output of the non-standard signal detection circuit ``5''. When the output is "φ", the output of the subtracter 9 is supplied to the output terminal 12 as a luminance signal without dot interference. The non-standard detection circuit 5 can be realized, for example, by a circuit as shown in FIG. 3 above.

In addition, the output of the non-standard detection circuit 5 is not only a two-stage output of "φ" ■, but also a multi-stage output such as "φ" ° "1" 2.
"3" (standard signal φ → 3 non-standard signals) is output in 4 stages, and according to the 4-stage output, the frequency characteristics of the bandpass filter 8 are changed to a wide band when the signal is in the standard signal state, and to a wide band when the signal is in the non-standard signal state. In this case, it is also possible to extract the color signal component by switching to a narrow band, and depending on the 4-stage output, the frequency characteristics of the notch filter 10 can be changed to a wide band when it is a luminance signal, and a wide band when it is a non-standard signal. It is also possible to switch to a narrow band and extract the luminance signal component.

Furthermore, the band pass filter 8 and the band pass filter 2
0 may be shared to form one bandpass filter. Further, the line comb filter 23 may be a band pass filter, or may be adaptively switched between a line comb filter and a band pass filter.

Effects of the Invention As described above, the present invention detects non-standard signals that do not meet the NTSC standard, such as home VTR playback signals and optical VDP special playback signals, and uses the detection results to detect non-standard signals that do not meet the NTSC standard. Furthermore, it is possible to detect a signal free from crosstalk interference due to interference between Y/C separated luminance signals and chrominance signals, and optimal signal processing can be performed on non-standard signals.

[Brief explanation of drawings]

1 and 2 are block diagrams showing the configuration of a video signal processing device in an embodiment of the present invention, FIG. 3 is a block diagram showing an example of the configuration of a non-standard signal detection circuit, and FIG. 4 is a block diagram of a notch filter. FIG. 5 is a frequency characteristic diagram of a bandpass filter, and FIG. 6 is a block diagram of a conventional video signal processing device. 1.51.101... Input terminal, 2,102.
...Frame comb filter, 3,103...
...Line comb filter, 4,104...
Motion detection circuit, 5.105...Non-standard signal detection circuit, 6,106...OR circuit, 7,11,1
07... Changeover switch, 8,108...
...Band pass filter, 9゜109...Subtractor, 10...Notch filter, 12.13,
60, 110, 111... Output terminal, 52...
...Frame capacity frame memory, 53...
・Adder, 54...Purst gate, 55...
... Absolute value circuit, 56 ... Ripple correction circuit, 57 ... Comparator, 5th ... Counting circuit, 59 ... Judgment circuit. Name of agent: Patent attorney Shigetaka Awano Haka 1 person missing

Claims (4)

[Claims] (1) A first means for detecting a non-standard signal in which a color subcarrier and horizontal and vertical scanning frequencies do not have a specific relationship from an input video signal, and separating the input signal by Y/C and separating luminance. A video signal processing device comprising: second means for applying a notch filter to a signal in accordance with the first means. (2) The first means for detecting a non-standard signal detects the amplitude of a color burst signal of the input video signal, compares the amplitude of the color burst signal with a predetermined reference value, and Claim (1) characterized by comprising means for counting the number of times that the amplitude of the color burst signal is equal to or greater than the reference value within an arbitrary period, and determining a non-standard state based on the counting result. video signal processing device. (3) a first means for detecting a non-standard signal in which the color subcarrier and the horizontal and vertical scanning frequencies do not have a specific relationship from the input video signal, and separating the input signal by Y/C and the separated luminance; a second means for applying a notch filter to the signal according to the first means; and a third means for switching the frequency characteristics of the bandpass filter according to the first means for the separated color signal. A video signal processing device comprising: (4) The first means for detecting a non-standard signal detects the amplitude of a color burst signal of the input video signal, detects the amplitude of the color burst signal, and detects the amplitude of the color burst signal and the amplitude of the color burst signal. and a means for counting the number of times that the amplitude of the color burst signal is equal to or greater than the reference value within an arbitrary period, and determining a non-standard state based on the counting result. The video signal processing device according to claim 3, characterized in that: