JPH03274888A - Motion adaptive type luminance signal/chrominance signal separating filter - Google Patents

Abstract

PURPOSE:To decrease the degradation of a picture quality by detecting a correlation between fields, in the case where it is decided to be an animated picture by a motion detecting circuit, selecting one of three kinds of in-three field YC separating circuit in accordance with whether its correlation is large or small, and outputting an in-three field YC separating Y signal and an in-three field YC separating C signal thereby. CONSTITUTION:A minimum value selecting circuit 34 detects the smallest one (the correlation is maximum) from in three kinds of absolute value inputs. That is, the minimum value selecting circuit 34 controls a signal selecting circuit 35 so that an output of a band pass filter 25, an output of a subtracter 26, and an output of a subtracter 27 are selected when an output of an absolute value circuit 31 is minimum, when an output of an absolute value circuit 32 is minimum, and when an output of an absolute value circuit 33 is minimum, respectively. An output of a signal selecting circuit 35 is outputted from an output terminal 13 as an in-three field YC separating C signal 113. Also, by subtracting the output of the selecting circuit 35 from an output of a two-picture element delaying circuit 19 by a subtracter 36, an in-three field YC separating Y signal 112 is obtained.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention provides a method for converting a luminance signal (hereinafter referred to as "signal") from a composite color television signal (hereinafter referred to as "■ signal") in which a color signal is frequency multiplexed into a high frequency region of a luminance signal. (Y signal or simply referred to as Y) and color signal (hereinafter referred to as C signal or simply C)
This invention relates to a motion-adaptive luminance signal and chrominance signal separation filter for separating .

[Prior Art] A motion-adaptive YC separation filter is a filter that locally determines whether an image is a still image or a moving image, and performs YC separation suitable for pixel signals of each part.

In the current NTSC signaling system, a composite signal is obtained by frequency multiplexing the C signal into the high frequency region of the Y signal. For this reason, YC separation is required in the television receiver, and incomplete separation causes image quality deterioration such as cross color and dot crawl.

Therefore, with the recent development of large-capacity digital memories, motion-adaptive YC separation using delay circuits (hereinafter simply referred to as delay circuits) having a delay time equal to or longer than the vertical scanning frequency of television signals has been developed. Various signal processing circuits have been proposed to improve image quality.

FIG. 15 is a block diagram showing an example of a conventional motion adaptive YC separation filter.

In the same figure, input terminal 1 has an NTSC V signal 1.
01 is input and applied to the input terminals of the intra-field YC separation circuit 4, the inter-frame YC separation circuit 5, the Y signal motion detection circuit 6, and the C signal motion detection circuit 7, respectively.

In the intra-field YC separation circuit 4, the intra-field YC separated Y signal 102 and the intra-field YC separated C signal 103, which are YC-separated by an intra-field filter (not shown), are respectively input to the first Y-signal mixing circuit 9. Input end and C
It is input to the first input terminal of the signal mixing circuit 10.

In addition, in the interframe YC separation circuit 5, the interframe YC separated by the interframe filter (not shown) is
Separated Y signal 104 and interframe YC separated C signal 105
are input to the second input terminal of the Y signal mixing circuit 9 and the second input terminal of the C signal mixing circuit IO, respectively.

On the other hand, the Y signal motion amount 106 detected by the Y signal motion detection circuit 6 is input to one input terminal of the synthesis circuit 8, and the C signal motion amount detected by the C signal motion detection circuit 7 is inputted to one input terminal of the synthesis circuit 8. The signal 107 shown is input to the other input terminal of the combining circuit 8. Motion detection signal 10 synthesized by the synthesis circuit 8
8 is input to the third input terminal of the Y signal mixing circuit 9 and the third input terminal of the C signal mixing circuit 10, respectively, and the Y signal motion detection circuit 6, the C signal motion detection circuit 7 and the synthesis circuit 8
A motion detection circuit 90 is configured.

A motion adaptive YCC separation multiplied signal 09, which is an output of the Y signal mixing circuit 9, is sent out from the output terminal 2. Further, a motion-adaptive YC-separated C signal 110, which is an output of the C signal mixing circuit IO, is sent out from the output terminal 3.

Next, the operation will be explained.

When the motion detection circuit 90 separates the signal 101 into Y and C, the motion detection circuit 90 includes the Y signal motion detection circuit 6 and the C signal motion detection circuit 7.
A synthesis circuit 8 synthesizes the outputs of 1 and 2 to determine whether the signal 101 is a signal representing a still image or a signal representing movement.

The Y signal motion detection circuit 6, for example, as shown in FIG.
A signal obtained by inputting the V signal 101 from the input terminal 51 and delaying it by one frame by the l-frame delay circuit 53 and the directly inputted V signal 101 are subtracted by the subtracter 54 to obtain the ■signal 10.
1, and apply a low-pass filter (hereinafter referred to as
After passing through 55 (referred to as LPF), its absolute value is determined by an absolute value circuit 56, and this absolute value is converted to Y by a nonlinear conversion circuit 57.
It is converted into a signal 106 indicating the amount of motion of the low frequency component of the signal and outputted to the output terminal 52.

Further, the C signal motion detection circuit 7 receives a signal obtained by delaying the V signal 101 inputted from the input terminal 11 by two frames in a two frame delay circuit 62 as shown in FIG. 17, and a directly inputted V signal. 101 is subtracted by a subtracter 63 to obtain a two-frame difference, which is passed through a band pass filter (hereinafter referred to as BPF) 64, its absolute value is determined by an absolute value circuit 65, and this absolute value is converted to a nonlinear The conversion circuit 66 converts the C signal into a signal 107 indicating the amount of movement, and outputs the signal 107 from the output terminal 61.

The synthesis circuit 8 is configured to select and output the larger value of the Y signal motion amount 106 and the C signal motion amount 107, for example.

This discrimination result is expressed in the form of a motion coefficient k (0≦≦1); for example, if the image is determined to be a completely still image, k = 0, and if the image is determined to be a completely moving image, k = 0. is given as a control signal 108 such that k=1.

Generally, when the image is a still image, interframe YC separation using interframe correlation is performed to separate the Y signal and C
Separate the signals.

The inter-frame YC separation circuit 5 adds a signal obtained by delaying the V signal 101 inputted from the input terminal 71 by one frame by one frame delay circuit 74 and the directly inputted V signal 101 as shown in FIG. 18, for example. The YF signal 104 is extracted from the YF signal 104 by calculating the l-frame sum, and
At the same time, the subtracter 76 subtracts the YF signal 104 from the V signal 101 input from the input end 71 to extract the CF signal 105 and output it from the output end 73.

Further, in general, when the image is a moving image, intra-field YC separation using intra-field correlation is performed to separate the Y signal and the C signal. The in-field YC separation circuit 4 is
For example, as shown in FIG. 19, the adder 85 adds the signal 101 input from the input terminal 81 delayed by one line in the one-line delay circuit 84 and the directly input V signal 101, resulting in a one-line sum. , and extract the Yf signal 102,
The Cf signal 103 is output from the output end 82 and is output from the output end 83 by subtracting the Yf signal 102 from the V signal 101 input from the input end 81 in the subtracter 86 .

In the motion adaptive YC separation filter, such an intra-field YC separation circuit 4 and an inter-frame YC separation circuit 5 are arranged side by side, and the motion coefficient k synthesized by the synthesis circuit 8 is used to
The signal mixing circuit 9 is caused to perform the following calculations, and a motion adaptive YCC separation multiplied signal 09 is outputted from the output terminal 2.

Y=kYf+ (1-k)YF where, Yf: In-field YC separated Y signal output 102, YF:
Interframe YC separated Y signal output 104.

Similarly, the control signal 108 causes the C signal mixing circuit IO to perform the following calculations, and outputs the motion adaptive YC separated C signal 110 from the output terminal 3.

C=kCf+ (1-k)CF where, Cf: In-field YC separation C signal output 103, CF+
7 frames YC interval C separation C signal output 105.

Of this motion adaptive YC separation filter, the C signal motion detection circuit 7 can also be realized with a configuration as shown in FIG.

In FIG. 20, a V signal 101 is input from an input terminal 11, and a color demodulation circuit 67 converts two types of color difference signals R-
It is demodulated into Y and B-Y.

These two types of color difference signals R-Y and B-Y are time-division multiplexed at a certain frequency in a time-division multiplexing circuit 68, delayed by two frames in a two-frame delay circuit 62, and then
By subtracting the output of the frame delay circuit 62 and the output of the time division multiplexing circuit 68, a two-frame difference is obtained.

The two-frame difference is passed through an LPF 69 to remove the Y signal component, an absolute value circuit 65 takes the absolute value, and a nonlinear conversion circuit 66 performs nonlinear conversion to obtain the motion detection amount of the C signal.
07 can be sent out from the output end 61.

[Problems to be Solved by the Invention] Since the conventional motion adaptive YC separation filter is configured as follows, the amount of motion detected by the Y signal motion detection circuit 6 and the C signal motion detection circuit 7 is combined. Based on the YC amount, the YC separation circuit 4 determines the
The f-times signal Cf signal and the YF-times signal CF signal from the inter-frame YC separation circuit 5 are mixed.

Therefore, because the filter characteristics for still images and those for moving images are completely different, there is an extreme change in resolution when moving from a still image to a moving image, or from a moving image to a still image. There was a problem in that the image quality was noticeably degraded.

This invention was made in order to solve the above-mentioned problems, and it is a motion-adaptive type that can reproduce images with high resolution and little image quality deterioration, even when the above-mentioned processing is changed frequently. The purpose is to obtain a YC separation filter.

[Means for Solving the Problems] The motion adaptive YC separation filter according to the present invention locally detects the correlation between fields when the motion detection circuit detects a moving image, and uses the detection result to determine the correlation between three fields. 3-field YC separated Y signal and 3-field YC separated Y signal and 3-field YC separated Y signal
This is provided with three intra-field YC separation circuits that output intra-field YC separation C signals.

[Function] The 3-field YC separation circuit of the present invention detects the correlation between fields when the motion detection circuit determines that it is a moving image, and selects three types of 3-field YC separation circuits depending on the magnitude of the correlation. By selecting either, 3-field YC separated Y signal and 3-field YC
Outputs a separated C signal.

[Example] Hereinafter, this invention will be explained based on the drawings.

FIG. 1 is a block diagram showing a motion adaptive YC separation filter according to an embodiment of the present invention.

In FIG. 1, the intra-field YC separation circuit 4 in FIG. 15 is replaced with a three-field YC separation circuit 50, and the other parts have been explained in the conventional example and will therefore be omitted.

A detailed block diagram of an embodiment of the three-field YC separation circuit 50 in FIG. 1 is shown in FIG.

In the figure, a V signal 101 is input to an input terminal 11. 14.21 is a 262-line delay circuit 15 is a 1-line delay circuit, 16.19.20 is a 2-pixel delay circuit, 17
．． 22 is a 4-pixel delay circuit, 18.23.24.26.2
7.36 is a subtractor.

25 is a band pass filter with a pass band of 2°I MHz or more, 28.29.30 is a low pass filter with a pass band of 2.1 MHz or less, 31.3233 is an absolute value circuit that outputs an absolute value, 34 is a minimum value selection circuit that determines the minimum value of three inputs and outputs a control signal, and 35 is a signal selection circuit that selects and outputs one of the three inputs. The output of the signal selection circuit 35 is outputted from the output terminal 13 as the 3-field YC-separated C signal 113, and the output of the subtracter 36 is the 3-field YC-separated Y signal 112.
It is outputted from the output terminal 12 as .

Next, the operation will be explained.

The horizontal direction of the screen is the X axis, and the vertical direction of the screen is the y axis.
If the t-axis, which is the time axis, is taken in the direction perpendicular to the plane composed of the axes, a three-dimensional space-time can be considered that can be composed of the X-axis, y-axis, and t-axis.

Figure 4(a) is a plan view configuring an array of V signals digitized at four times the color subcarrier in three-dimensional space-time on the t-axis and y-axis, and Figure 4(b) is a plan view of the arrangement of V signals digitized at four times the color subcarrier in three-dimensional space-time. ) is a plan view configuring the arrangement of V signals along the X-axis and the y-axis.

FIG. 4(a) also shows interlaced scanning lines,
The dashed line indicates one field, and the solid line indicates that the color subcarriers are in phase. In addition, Fig. 4 (b
The solid lines and broken lines in ) indicate the scanning lines of n field and n-1 field, respectively, and "◎" and "
・", "△" and "mu" indicate sample points where the color subcarrier is in phase when the V signal is digitized at four times the color subcarrier frequency fsc (=3.58MHz). There is.

Now, if the sample point of interest is represented by "◎", the color subcarrier phase is 180 degrees at around 2 sample points in the same field, field n, and at four points a, b, c, and d above and below the l line.
It's different.

Therefore, a line comb filter using a digital circuit or an adaptive Y
A C separation filter etc. can be configured.

Further, as shown in FIG. 4(a), since the color subcarrier phases differ by 180 degrees at the same sample point one frame apart, an interframe YC separation filter can also be constructed.

Furthermore, as can be seen from Figure 4(b), in the n-1 field one field before the sample point of interest, the phase is opposite around the sample point on the ■ line or two sample points below the l line, so Inter-field YC separation is possible by calculating any one of these three points A, B, and B with the point of interest.

Furthermore, considering the μ-axis which is the horizontal frequency axis, the ν-axis which is the vertical frequency axis, and the f-axis which is the time-frequency axis as the frequency axes corresponding to the above X-axis, ν-axis, and f-axis, the μ-axis is orthogonal to each other. , ν axis, and f axis can be considered.

FIG. 5 shows a projection of the three-dimensional frequency space. FIG. 5(a) is a diagram of the three-dimensional frequency space viewed from an oblique direction, FIG. 5(b) is a diagram of the three-dimensional frequency space viewed from the negative direction of the f-axis, and FIG. 5(c) is a diagram of the three-dimensional frequency space viewed from an oblique direction. is a diagram of the above three-dimensional frequency space viewed from the positive direction of the μ axis.

FIGS. 5(a) to 5(c) show the spectral distribution of the ■ signal on the three-dimensional frequency space. Figure (a)~
As can be seen from (C), the spectrum of the Y signal spreads around the origin of the three-dimensional frequency space, and the spectrum of the C signal is obtained by quadrature two-phase modulation of the ■ signal and the C signal at the color subcarrier frequency fsc. Therefore, they are located in four spaces as shown in FIGS. 5(a) to 5(C). However, Fig. 5 (c
) When looking at the ■ signal on the μ axis, the C signal exists only in the second and fourth quadrants.

This corresponds to the fact that the solid line representing the same phase of the color subcarriers rises with time in FIG. 4(b).

Nevertheless, in the conventional example, when motion of an image is detected, YC separation is performed using correlation within the field, so band limitation in the μ-axis and ν-axis directions is possible, but band limitation in the f-axis direction is It was not possible to add directional band limits.

Therefore, the frequency space in which the Y signal originally exists is separated as the C signal, and the band of the Y signal in the moving image becomes narrow.

Therefore, by performing YC separation using inter-field processing as described above, the band of the Y signal in a moving image can be expanded.

As mentioned above, the C signal exists only in the second and fourth quadrants in Fig. 5(c), so the difference between the sample point of interest "◎" and the sample point A "・" in Fig. 4(b) is By calculation, high frequency components on a three-dimensional frequency space including the C signal can be extracted.

This bandpass filter consists of a 262-line delay circuit 14 and a
It is composed of a line delay circuit 15 and a subtracter 18, and the output of the subtracter 18 becomes a high frequency component on a three-dimensional frequency space. A C signal can be obtained by passing this high frequency component through a horizontal band pass filter 25. Furthermore, the Y signal can be obtained by subtracting the C signal from the ■ signal. This is referred to as 3-field YC separation A.

Figures 6(a) to (c) are the same as Figures 5(a) to (c) (representing a three-dimensional frequency space, and Y within three fields.
It shows the frequency space in which the Y signal and C signal obtained by C separation A exist.

Next, the C signal is obtained by performing an operation on the high frequency component obtained from the output of the subtractor 18 between the sample point of interest "◎" and the sample point "・" in FIG. 4(b). be able to. This C signal is extracted by performing arithmetic operations on the two sample points in a subtracter 26. Also, from the V signal to the C
The Y signal can be obtained by subtracting the signals.

This is referred to as 3-field YC separation B.

FIGS. 7(a) to 7(c) show the frequency space in which the Y signal and C signal exist, obtained by YC separation B within three fields.

Next, the C signal is obtained by performing calculations on the high frequency component obtained from the output of the subtractor 18 between the sample point of interest "◎" and the sample point A "・" in FIG. 4(b). Obtainable. This C signal is extracted by performing calculations on the two sample points in a subtracter 27. Furthermore, the Y signal can be obtained by subtracting the C signal from the ■ signal. This is referred to as 3-field YC separation C.

FIGS. 8(a) to 8(c) show the frequency space in which the Y signal and C signal exist, obtained by yc separation C within three fields.

In order to adaptively switch and control these three types of 3-field YC separation, the sample point of interest “◎
It is necessary to detect the correlation between `` and sample points ``・'' A, B, and tsu. The correlation between the sample point ``◎'' of interest and the sample points ``・'' A, I, and A in Fig. 4 (b) is determined by passing the respective differences through a low-pass filter, and then Detection based on frequency components.

In Figure 4(b), the sample point of interest “◎” and the sample point A “・
” is detected as follows.

After the output of the subtracter 18 is delayed by a two-pixel delay circuit 20,
The signal is passed through a low pass filter 28 to extract horizontal low frequency components. The output of the low-pass filter 28 is input as an absolute value to the minimum value selection circuit 34 by the absolute value circuit 31, and the correlation between the sample point of interest "◎" and the sample point A "・" in FIG. 4(b) is determined. Detected.

The solid line portion in FIG. 9(a) to (c) is the low-pass filter 2.
This is a three-dimensional frequency domain obtained from the output of 8, and is a frequency domain in which the spread of the spectrum of the Y signal is detected because the 3-field YC separation A is not selected.

Further, the correlation between the sample point of interest "◎" and the sample point "." in FIG. 4(b) is detected as follows.

Calculations on the two sample points are performed by a subtracter 23, and the output of the subtracter 23 is passed through a low pass filter 29 to extract horizontal low frequency components.

The output of the low-pass filter 29 is inputted as an absolute value by the absolute value circuit 32 to the minimum value selection circuit 34, and the fourth
A correlation is detected between the sample point of interest "◎" and the sample point "." in FIG. 3(b).

The solid line portion in Fig. 1θ (a) to (c) is the three-dimensional frequency domain obtained from the output of the low-pass filter 29, and since YC separation B within three fields is not selected, the spread of the spectrum of the Y signal is detected. It is in the frequency domain.

Further, the correlation between the sample point of interest "◎" and the sample point A "." in FIG. 4(b) is detected as follows.

Calculations on the two sample points are performed by a subtracter 24, and the output of the subtracter 24 is passed through a low pass filter 30 to extract horizontal low frequency components. The output of the low-pass filter 30 is input as an absolute value to the minimum value selection circuit 34 by the absolute value circuit 33, and the correlation between the sample point of interest "◎" and the sample point A "・" in FIG. 4(b) is determined. is detected.

The solid line portion in FIGS. 11(a) to (c) is the three-dimensional frequency domain obtained from the output of the low-pass filter 30, and the spread of the spectrum of the Y signal is detected because YC separation C within three fields is not selected. It is in the frequency domain.

The minimum value selection circuit 34 detects the minimum value (the value with the maximum correlation) from among the three types of absolute value inputs. That is, the minimum value selection circuit 34 selects the output of the bandpass filter 25 when the output of the absolute value circuit 31 is the minimum, and the output of the subtracter 26 when the output of the absolute value circuit 32 is the minimum, and the output of the subtracter 26 when the output of the absolute value circuit 32 is the minimum.
When the output of subtracter 27 is the minimum, the signal selection circuit 35 is controlled to select the output of the subtracter 27. The output of the signal selection circuit 35 is outputted from the output terminal 13 as a 3-field YC separated C signal 113. Further, by subtracting the output of the signal selection circuit 35 from the output of the two-pixel delay circuit 19 by a subtracter 36, a three-field YC separated Y signal 112 is obtained.

FIG. 3 is a detailed block diagram of another embodiment of the three-field YC separation 50 in FIG. 1 according to the present invention.

In the figure, 37 is a two-pixel delay circuit, 38 is a subtracter,
39.40 is an adder, 41 is a low pass filter with a passband of 2.1MHz or less, 42.43 is a bandpass filter with a passband of 2.1MHz or more, and 44 is a maximum filter for three inputs. This is a maximum value selection circuit that determines the value and outputs a control signal.

Next, the operation will be explained.

The only difference in FIG. 3 from FIG. 2 is the method of detecting correlation between fields.

In Figure 4(b), the sample point of interest “◎” and the sample point A “・
” is detected as follows.

In Figure 4(b), the noted sample point “◎” and the sample point “○”
'' is performed by the subtracter 38, and high frequency components on the three-dimensional frequency space are extracted. From the output of the subtracter 38, a horizontal low frequency component is extracted by a low pass filter 41. The output of the low-pass filter 41 is input as an absolute value to the maximum value selection circuit 44 by the absolute value circuit 31, and the correlation between the sample point of interest "◎" and the sample point A "・" in FIG. 4(b) is determined. is detected.

The solid line portion in FIGS. 12(a) to (C) is the three-dimensional frequency domain obtained from the output of the low-pass filter 41, and the spread of the spectrum of the Y signal is detected for selecting YC separation A within three fields. It is in the frequency domain.

Further, the correlation between the sample point of interest "◎" and the sample point "." in FIG. 4(b) is detected as follows.

The two sample points are added by an adder 39, and then passed through a bandpass filter 42 to extract a horizontal high frequency component. The output of the band pass filter 42 is inputted as an absolute value by the absolute value circuit 32 to the maximum value selection circuit 44, and the correlation between the sample point of interest "◎" and the sample point "." in FIG. 4(b) is detected. be done.

The solid line portion in FIGS. 13(a) to (C) is the three-dimensional frequency domain obtained from the output of the bandpass filter 42, and the frequency at which the spread of the spectrum of the Y signal is detected for selecting YC separation B within three fields. It is an area.

Further, the correlation between the sample point of interest "◎" and the sample point A "." in FIG. 4(b) is detected as follows.

The two sample points are added by an adder 40, and a horizontal high frequency component is extracted through a band pass filter 43. The output of the band pass filter 43 is inputted as an absolute value by the absolute value circuit 32 to the maximum value selection circuit 44, and the correlation between the sample point of interest "◎" and the sample point A "・" in FIG. 4(b) is determined. Detected.

The solid line portion in FIGS. 14(a) to (c) is the three-dimensional frequency domain obtained from the output of the bandpass filter 43, and the frequency at which the spread of the spectrum of the Y signal is detected for selecting YC separation C within three fields. It is an area. The maximum value selection circuit 44 detects the maximum one (the one with the maximum correlation) among the three types of absolute value inputs and controls the signal selection circuit 35 .

[Effects of the Invention] As described above, according to the present invention, when the motion detection circuit detects a moving image, the 3-field YC separation circuit
Since the configuration is configured to locally detect the correlation between fields and adaptively select a plurality of interfield calculations including calculations between three fields, it is possible to detect the correlation between images in video processing using a motion adaptive YC separation filter. This makes it possible to perform optimal YC separation using this method, and has the effect of configuring a motion adaptive YC separation filter that performs YC separation with little deterioration in resolution even in moving images.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a motion adaptive YC separation filter according to an embodiment of the present invention, and FIG.
3 is a block diagram showing the detailed configuration of the intra-field YC separation circuit, FIG. 3 is a block diagram showing the detailed configuration of another embodiment of the 3-field YC separation circuit in FIG. 1, and FIG. In the dimensional space and time, the color subcarrier is 4 times as large as the digitized V signal array on the f-axis and the y-axis. A plan view consisting of the X-axis and the y-axis, FIG. 5(a) is a diagram of the spectrum distribution of the V signal in a three-dimensional frequency space viewed from an oblique direction, and FIG. 5(b) is a diagram of the spectral distribution in FIG. 5(a). A diagram of the spectral distribution viewed from the negative direction of the f-axis, Figure 5 (c
) is a diagram of the spectral distribution in FIG. 5(a) viewed from the positive direction of the μ axis, and FIG. 6(a) is the Y signal and C signal obtained by the first three-field YC separation according to the present invention. Figure 6(b) is a diagram of the spectral distribution of Figure 6(a) viewed from an oblique direction in a three-dimensional frequency space, Figure 6(C) is a diagram of the spectrum distribution of Figure 6(a) viewed from the negative direction of the f axis. ) is a diagram of the spectral distribution in FIG. 6(a) viewed from the positive direction of the μ axis, and FIG. 7(a) is the Y signal and C signal obtained by the second 3-field YC separation according to the present invention. Fig. 7(b) is a diagram of the spectral distribution in Fig. 7(a) seen from an oblique direction on a three-dimensional frequency space, and Fig. 7(C ) is a diagram of the spectral distribution in Figure 7(a) viewed from the positive direction of the μ axis;
Figure (a) is a diagram of the spectral distribution of the Y signal and C signal obtained by the third three-field YC separation according to the present invention viewed from an oblique direction on a three-dimensional frequency space, and Figure 8 (b) is a diagram of the spectrum distribution of the Y signal and C signal obtained by the third three-field YC separation according to the present invention. Figure 8(a)' is a diagram of the spectral distribution seen from the negative direction of the f axis, and Figure 8(c) is a diagram of the spectral distribution in Figure 8(a) viewed from the positive direction of the μ axis. . 9 to 11 are diagrams showing the frequency domain of correlation detection in the embodiment of FIG. 2, and FIG.
Figure 9(b) is a diagram of the frequency domain of correlation detection for not selecting an intra-field YC separation filter viewed from an oblique direction on a three-dimensional frequency space.
Figure 9 (c) is a diagram of the frequency domain in Figure 9 viewed from the positive direction of the μ axis, Figure 10 (
Figure 10(b) is a diagram of the frequency domain of correlation detection for not selecting the second three-field YC separation filter viewed from an oblique direction on a three-dimensional frequency space.
) is seen from the negative direction of the f-axis, and Fig. 10 (c) shows the frequency domain in Fig. 1θ (a) as μ
FIG. 11(a) is a diagram of the frequency domain of correlation detection for not selecting the third three-field YC separation filter, viewed from an oblique direction on a three-dimensional frequency space. Figure 11(b) is a diagram of the frequency domain in Figure 11(a) viewed from the negative direction of the f axis, and Figure 11(c) is a diagram of the frequency domain in Figure 11(a) viewed from the positive direction of the μ axis. It is a figure seen from the direction. 12 to 14 are diagrams showing the frequency domain of correlation detection in the embodiment of FIG. 3, and FIG.
Figure 12(b) is a diagram of the frequency domain of correlation detection for selecting the three-field YC separation filter viewed from an oblique direction on a three-dimensional frequency space. View from the negative direction, Figure 12(c)
is a diagram of the frequency domain in FIG. 12(a) viewed from the positive direction of the μ axis, and FIG. 13(a) is the Y in the second three fields.
A diagram of the frequency domain of correlation detection for selecting a C separation filter viewed from an oblique direction on a three-dimensional frequency space. Figure 13 (b) shows the frequency domain of Figure 13 (a) in the negative direction of the f axis. 13(c) is a diagram of the frequency region in FIG. 13(a) viewed from the positive direction of the μ axis, and FIG.
Figure (a) is a diagram of the frequency domain of correlation detection for selecting the third three-field YC separation filter viewed from an oblique direction on a three-dimensional frequency space, and Figure 14 (b) is a diagram of the frequency domain of correlation detection for selecting the third three-field YC separation filter.
A diagram of the frequency domain in a) viewed from the negative direction of the f axis,
FIG. 14(c) is a diagram of the frequency domain in FIG. 14(a) viewed from the positive direction of the μ axis, FIG. 15 is a block diagram of a conventional motion adaptive YC separation filter, and FIG. FIG. 17 is a block diagram showing the detailed configuration of the Y signal motion detection circuit in the motion adaptive YC separation filter shown in FIG.
FIG. 18 is a block diagram showing the detailed configuration of the C signal motion detection circuit in the motion adaptive YC separation filter shown in FIG.
FIG. 19 is a block diagram showing a detailed configuration of the inter-frame YC separation circuit in the motion adaptive YC separation filter of FIG. 5, and FIG. 19 shows a detailed configuration of the intrafield YC separation circuit of the motion adaptive YC separation filter of FIG. Block Diagram,
FIG. 20 is a block diagram showing another example of the conventional C signal motion detection circuit. 5... Inter-frame YC separation circuit, 6... Y signal motion detection circuit, 7... C signal motion detection circuit, 8... Synthesis circuit, 9... Y signal mixing circuit, 10... C signal mixing circuit 50...3 field YC separation circuit, 90...
・Motion detection circuit. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. (a) ν Figure 6 Ca (b) (C) Figure 5 (a) Figure 7 (a) Figure 10 (b) (8) Figure 11 (c) (b) Cb) (a) (a) Figure 14 (C) <C) Cb) (a) (c) Figure 16 Figure 17 Figure 19 Procedural amendment (voluntary) 5. Subject of amendment 2008 513♂ Regarding the invention in the description Column 6 for detailed explanation and brief explanation of drawings, contents of amendments

Claims (2)

[Claims] (1) In a circuit that separates the luminance signal and chrominance signal from a composite color television signal in which the chrominance signal is frequency-multiplexed into the high frequency region of the luminance signal, image movement is locally detected using the correlation between frames. A motion detection circuit that detects a still image, and when this motion detection circuit detects a still image, separates the interframe luminance signal and color signal using interframe correlation to generate the interframe luminance signal, color signal, and separate luminance signal and interframe luminance signal. Color signal separation When the interframe luminance signal color signal separation circuit that outputs the color signal and the motion detection circuit detect a moving image, the horizontal low frequency of the difference at the point where the phase of the color subcarrier is opposite between fields Correlations are locally detected based on the components, and based on the detection results, processing is performed to adaptively switch multiple inter-field processes including calculations between three fields, and three-field intra-luminance signal, color signal, and separated color signals are output. , and a 3-field luminance signal chrominance signal separation circuit that outputs a 3-field luminance signal chrominance signal separated luminance signal by subtracting the 3-field luminance signal chrominance signal separated color signal from the original composite color television signal; A luminance signal mixing circuit that mixes the inter-frame luminance signal, chrominance signal, and separated luminance signal and the three-field luminance signal, chrominance signal, and separated luminance signal based on the output of the motion detection circuit, and outputs a motion-adaptive luminance signal, chrominance signal, and separated luminance signal. and a color signal that mixes the inter-frame luminance signal, chrominance signal, and separated color signal based on the output of the motion detection circuit and the three-field luminance signal, chrominance signal, and separated color signal to output a motion-adaptive luminance signal, chrominance signal, and separated chrominance signal. A motion-adaptive luminance signal/chrominance signal separation filter characterized by comprising a mixing circuit. (2) When the motion detection circuit detects a moving image instead of the intra-field luminance signal color signal separation circuit, the horizontal low frequency component and phase of the difference at the point where the phase of the color subcarrier is the same between fields Correlation is detected locally by obtaining the horizontal high frequency component of the sum at the point where by outputting the 3-field luminance signal, chrominance signal, and separated color signal, and subtracting the 3-field luminance signal, chrominance signal, and separated color signal from the original composite color television signal.
In-field luminance signal chrominance signal Separated luminance signal output 3
2. The motion adaptive luminance and chrominance signal separation filter according to claim 1, wherein the filter is replaced with an intra-field luminance and chrominance signal separation circuit.