KR940002198B1 - Motion adaptive luminance signal and chrominance signal separation filter - Google Patents

Abstract

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Description

Motion adaptive luminance signal color signal separation filter

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

FIG. 2 is a block diagram showing the detailed configuration of the first embodiment of the YC separation circuit in the three fields in the embodiment of FIG.

FIG. 3 is a block diagram showing the detailed configuration of the second embodiment of the YC separation circuit in the three fields in the embodiment of FIG.

4 is a block diagram showing the detailed configuration of the third embodiment of the YC separation circuit in the three fields in the embodiment of FIG.

FIG. 5A is a plan view of an array of four-times digitalized V signals of a color subcarrier in a three-dimensional space-time with t- and y-axes. FIG.

5B and 5C are plan views in which the arrangement of the V signals in FIG. 5A is composed of the x-axis and the y-axis.

FIG. 6A is a view of the spectral distribution of the V signal in an inclined direction in three-dimensional frequency space. FIG.

FIG. 6B is a view of the spectral distribution of FIG. 6A seen in the negative direction of the f-axis. FIG.

FIG. 6C is a view of the spectral distribution of FIG. 6A viewed from the positive direction of the µ layer. FIG.

Fig. 7A is a view of the spectral distribution of the C signal of the Y signal obtained by the YC separation in the first three fields according to the present invention in a direction inclined in three-dimensional frequency space.

FIG. 7B is a view of the spectral distribution of FIG. 7A seen in the negative direction of the f-axis. FIG.

FIG. 7C is a view of the spectral main fabric of FIG. 7A seen from the positive direction of the µ axis. FIG.

Fig. 8A is a view of the spectral distributions of the Y and C signals obtained by the second three-field YC separation according to the present invention in an inclined direction in three-dimensional frequency space.

FIG. 8B is a view of the spectral distribution of FIG. 8A seen in the negative direction of the f-axis. FIG.

FIG. 8C is a view of the spectral distribution of FIG. 8A seen from the positive direction of the µ axis. FIG.

Fig. 9A is a view of the spectral distribution of the Y and C signals obtained by the third three-field YC separation according to the present invention in an inclined direction in three-dimensional frequency space.

FIG. 9B is a view of the spectral distribution of FIG. 9A seen in the negative direction of the f-axis. FIG.

FIG. 9C is a view of the spectral distribution of FIG. 9A seen from the positive direction of the µ axis. FIG.

10 is a block diagram of a conventional motion adaptive YC separation filter.

FIG. 11 is a block diagram showing a detailed configuration of a Y signal motion detection circuit in the motion adaptive YC separation filter of FIG.

FIG. 12 is a block diagram showing a detailed configuration of a C signal motion detection circuit in the motion adaptive YC separation filter of FIG.

FIG. 13 is a block diagram showing a detailed configuration of an interframe YC separation circuit in the motion adaptive YC separation filter of FIG.

FIG. 14 is a block diagram showing the detailed configuration of the in-field YC separation circuit in the motion adaptive YC separation filter of FIG.

15 is a block diagram showing another example of a conventional C signal motion detection circuit.

* Explanation of symbols for main parts of the drawings

5: YC separation circuit between frames 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: YC separation circuit in frame 80: motion detection circuit

According to the present invention, a color signal (hereinafter referred to as a V signal) and a color signal (hereinafter referred to as Y signal or Y) and color signal (hereinafter referred to as C signal or C) are frequency-multiplexed in the high frequency region of the luminance signal. A motion adaptive luminance signal color signal separation filter.

The conventional motion adaptive YC separation filter is a filter which locally determines whether an image is a still image or a motion image, and performs YC separation suitable for the pixel signal of each part.

In the current NTSC signal system, a complex circuit is obtained by multiplying the C signal in the high frequency region of the Y signal. For this reason, YC separation is necessary in the receiver, and the incompleteness of the separation causes deterioration of image quality such as cross color and dot claw.

Therefore, with the recent development of large-capacity digital memories, signal processing circuits for image quality improvement such as motion adaptive YC separation using delay circuits (hereinafter referred to as delay circuits) having a delay time equal to or higher than the vertical scanning frequency of a television signal are described. Has been proposed.

10 is a block circuit diagram showing an example of a conventional motion adaptive YC separation filter. In FIG. 10, the NT signal V signal 101 is input to the input terminal 1, the YC separation circuit 4 in the field, the YC separation circuit 5 between frames, the Y signal motion detection circuit 6, and It is applied to the input terminal of the C signal motion detection circuit 7, respectively.

The in-field YC separation Y signal 102 and the in-field YC separation C signal 103 which are YC separated by the in-field filter (not shown) in the in-field YC separation circuit 4 are respectively Y signal mixing circuit 9. Is input to the first input terminal of and the first input terminal of the C signal mixing circuit 10.

In addition, the inter-frame YC separation Y signal 104 and the inter-frame YC separation C signal 105 separated by YC by the inter-frame filter (not shown) in the inter-frame YC separation circuit 5 are respectively Y signal mixed circuits ( The second input terminal of 9) and the second input terminal of the C signal mixing circuit 10 are input.

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 detected. A signal 107 indicating is input to the other input terminal of the synthesis circuit 8.

The motion detection signal 108 synthesized by the synthesis circuit 8 is input to the third input terminal of the Y new 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 motion detection circuit 80 is constituted by the C signal motion detection circuit 7 and the synthesis circuit 8.

The motion adaptive YC separation Y signal 109, which is the output of the Y signal mixing circuit 9, is sent to the output terminal 2. As shown in FIG. The motion adaptive YC separation C signal 110, which is the output of the C signal mixing circuit 10, is also output from the output stage 3.

Next, the operation of the conventional example will be described.

The motion detection circuit 80 separates the V signal 101 by YC, and combines the outputs of the Y signal motion detection circuit 6 and the C signal motion detection circuit 7 in the synthesis circuit 8, and the V signal ( It is discriminated whether or not the signal 101 indicates a signal indicating a stationary image or a signal indicating motion.

For example, as shown in FIG. 11, the Y signal motion detection circuit 6 inputs the V signal 101 at the input terminal 51 and delays one frame in the one frame delay circuit 53 and the directly input V signal ( Subtract 101 from the subtractor 54 to obtain one frame difference of the V signal 101, pass through the low pass filter (hereinafter referred to as LPF) and 55, and then use the absolute value circuit 56 to determine the absolute value. The absolute value is converted into a signal 106 representing the amount of motion of the low-frequency component of the Y signal by the nonlinear conversion circuit 57 and output to the output terminal 52.

In addition, the C signal motion detection circuit 7 is a signal in which the V signal 101 input from the input terminal 11 is delayed by two frames by the two frame delay circuit 81 and the V signal directly input, for example, as shown in FIG. Subtract 101 from the subtractor 82 to find the difference between two frames, pass the bandpass filter (hereinafter referred to as BPF), and 83, and then obtain the absolute value from the absolute value circuit 84. The value is converted by the nonlinear conversion circuit 85 into a signal 107 representing the amount of motion of the C signal, and outputted by the output terminal 89.

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

k

1)라는 형태로 표시되고, 예를들면 화상을 완전한 정지화상으로 판별한 경우에는 k=0, 화상을 완전한 움직임화상으로 판별한 경우에는 k=1이라는 제어신호(108)로서 부여된다.The result of this determination is the motion coefficient K (0

k

1). For example, it is given as a control signal 108 such that k = 0 when an image is identified as a complete still image and k = 1 when an image is identified as a full motion image.

In general, when an image is a still image, YC separation and C signal are separated by performing interframe YC separation using interframe correlation.

The inter-frame YC separation circuit 5 is, for example, a signal in which the V signal 101 input to the input terminal 61 is delayed by one frame by the one frame delay circuit 64 as shown in FIG. 101 is added by the adder 65, the sum of one frame is obtained, the YF signal 104 is extracted and output to the output terminal 62, and the V signal 101 input from the input terminal 61 by the subtractor 66. ), The CF signal 105 is extracted and output from the output terminal 63 by subtracting the YF signal 104.

In general, when the image is a moving image, in-field YC separation using intra-field correlation is performed to separate the Y and C signals. In the field YC separation circuit 4, for example, as shown in FIG. 14, the V signal 101 input from the input terminal 71 is delayed by one line by the one line delay circuit 74 and the V signal directly input ( 101 is added by the adder 75 to obtain a one-line sum to extract the Yf signal 102 and output it at the output terminal 72 and at the V signal 101 input from the input terminal 71 at the subtractor 76. By subtracting the Yf signal 102, the Cf signal 103 is extracted and output from the output terminal 73.

In the motion adaptive YC separation filter, such an in-field YC separation circuit 4 and an inter-frame YC separation circuit 5 are arranged side by side, and by the motion coefficient k synthesized in the synthesis circuit 8, the Y signal mixing circuit ( The following operation is executed in 9) to output the motion adaptation YC separation Y signal 109 from the output stage 2.

Y = kYf + (1-k) YF

here,

Yf: YC separation Y signal output 102 in the field,

YF: YC separation Y signal output 104 between fields.

Similarly, the control signal 108 performs the following operation on the C signal mixing circuit 10 to output the motion adaptive YC separation C signal 110 at the output stage 3.

C = kCf + (1-k) CF

here,

Cf: YC separation C signal output 103 in field,

CF: YC separation between fields C signal output 105.

The C signal motion detection circuit 7 in this motion adaptive YC separation filter can also be realized with the configuration similar to that of FIG. In the same figure, the V signal 101 is input from the input terminal 11, and is demodulated by the color demodulation circuit 86 into two kinds of color difference signals R-Y and B-Y.

These two kinds of color difference signals RY and BY are time division multiplexed at an arbitrary frequency in the time division multiplexing circuit 87, and the subtractor 82 subtracts the output of the two frame delay circuit 81 and the output of the time division multiplexing circuit 87. 2 frame differences are obtained by executing.

In this two-frame difference, the Y signal component is removed through the LPF 88, the absolute value is taken by the absolute value circuit 84, and the non-linear conversion is performed by the nonlinear conversion circuit 85 to detect the motion of the C signal 107. Can be sent from the output terminal (89).

Since the conventional motion adaptive YC separation filter is constituted as described above, the field or YC separation circuit is combined according to the combined amount of motion detected by the Y signal motion detection circuit 6 and the C signal motion detection circuit 7 respectively. The Yf signal and the Cf signal according to (4) and the YF signal and CF signal by the inter-frame YC separation circuit 5 are respectively mixed.

Therefore, since the filter characteristics in the still image and the filter characteristics in the moving image are completely different, there is an extreme change in resolution when the image is moved from the still image to the moving image or when the image is moved from the moving image to the still image. There was a problem that the degradation of the image quality during image processing was noticeable.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above problems, and to provide a moving adaptive YC separation filter capable of reproducing an image having a high resolution and a low quality deterioration even in an image having many switching processes.

The motion adaptive YC separation filter according to the present invention detects a correlation between frames locally when the motion detection circuit detects a motion image, and adaptively processes several inter-field processes including computation between three fields based on the detection result. The three-field YC separation circuit for outputting the three-field YC separation Y signal and the three-field YC separation C signal is provided.

In the present invention, the three-field YC separation circuit in the present invention detects a correlation between frames when the motion detection circuit judges a motion image, and selects one of three types of three-field YC separation circuits by the magnitude of the correlation. YC-separated Y signal in three fields and YC-separated C signal in three fields are output.

Hereinafter, the present invention will be described with reference to the drawings.

1 is a block diagram showing a motion adaptive luminance signal color signal separation filter according to an embodiment of the present invention. In FIG. 1, the part of the YC separation circuit 4 in the field in FIG. 10 is replaced with the YC separation circuit 50 in the three fields, and the other parts are omitted because they have been explained in the prior art.

FIG. 2 shows a detailed block diagram of the first embodiment of the YC separation circuit 50 in the three fields in FIG.

In this figure, the V signal 101 is input to the input terminal 11. The V signal 10l is input to the input terminal of the 262 line delay circuit 14, the one line delay circuit 28, and the two pixel delay circuit 3 and the first input terminal of the subtractor 16.

The 262 line delayed V signal in the 262 line delay circuit 14 is input to the input terminal of the 1 line delay circuit 15. The V signal delayed by one line by the one line delay circuit 15 is input to the input terminal of the 262 line delay circuit 17, the two pixel delay circuit 20, and the second input terminal of the subtractor 16, respectively. The 262 line delayed V signal from the 262 line delay circuit 17 is input to the input terminal of the one line delay circuit 18, the four pixel delay circuit 30, and the first input terminal of the subtractor 32, respectively. The V signal delayed by one line in the one line delay circuit 18 is input to the input terminal of the two pixel delay circuit 21.

The output of the subtractor 16 is input to the input terminal of the one line delay circuit 19. The output of the one line delay circuit l9 is input to the input terminal of the four pixel delay circuit 22 and the first input terminal of the adder 24. The output of the four pixel delay circuit 22 is input to the first input terminal of the adder 23.

The two pixel delayed V signal in the two pixel delay circuit 20 is input to the first input terminals of the subtractor 25, the adder 27, and the subtractor 41, respectively. The output of the two pixel delay circuit 21 is input to the subtractor 25, the second input terminal of the adder 27 and the first input terminal of the subtractor 34. The output of the subtractor 25 is input to the second input terminal of the adders 23, 24 and the input terminal of the LPF 26. The output of the adder 27 is input to the first input terminal of the adder 40.

The output signal of the adder 23 is input to the first input terminal of the signal selection circuit 39. The output signal of the adder 24 is input to the second input terminal of the signal selection circuit 39. The output signal of the LPF 26 is input to the third input terminal of the signal selection circuit 39.

The V signal delayed by one line in the one line delay circuit 28 is input to the input terminal of the four pixel delay circuit 29 and the first input terminal of the subtractor 33. The 4-pixel delayed V signal in the 4-pixel delay circuit 29 is input to the second input terminal of the subtractor 32. The 4-pixel delayed V signal in the 4-pixel delay circuit 30 is input to the second input terminal of the subtractor 33. The two pixel delayed V signal in the two pixel delay circuit 31 is input to the second input terminal of the subtractor 34.

The output of the subtractor 32 is at the input of the absolute value circuit 35, the output of the subtractor 33 is at the input of the absolute value circuit 36, and the output of the subtractor 34 is at the input of the absolute value circuit 37. Each is input.

The output of the absolute value circuit 35 is connected to the first input terminal of the minimum value selection circuit 38, and the output of the absolute value circuit 36 is connected to the second input terminal of the minimum value selection circuit 38. Are respectively input to the third input terminal of the minimum value selection circuit 38.

The output of the minimum value selection circuit 38 is input to the fourth input terminal of the signal selection circuit 39, thereby selectively controlling the first to third inputs.

The output of the signal selection circuit 39 is input to the second input terminal of the adder 40. The output of the adder 40 is input to the second input terminal of the subtractor 41, and output from the output terminal 12 as the YC separation Y signal 112 in three fields. The output of the subtractor 41 is output from the output terminal 13 as the YC separation C signal 113 in three fields.

Next, the operation will be described.

If the horizontal direction of the screen is x-axis, and the vertical direction of the screen is y-axis, and the t-axis, which is the time axis in the direction perpendicular to the plane composed of the x-axis and y-axis, can be configured as the x-axis, y-axis, and t-axis. Three-dimensional space-time can be considered.

FIG. 5 is a view showing a three-dimensional spacetime, FIG. 5A is a plane composed of a t-axis and a y-axis, and FIGS. 5B and C are planes composed of an x-axis and a y-axis. FIG. 5A also shows an interlaced scanning line, and the dotted line shows that one field and the solid line shows that the color carrier is in phase.

In addition, solid lines and dotted lines in FIG. 5B represent scanning lines of n fields and n-1 fields, respectively, and four types of marks on the scanning lines (○, ●, Δ, and ▲) show V signals with color carrier frequency fsc (= 3.58). The color carriers at the time of digitalization of 4 times (MHz) show the sampling point of the same phase.

In addition, the solid line and the dotted line of FIG. 5C represent the scanning line of n + 1 field and n field, respectively, and the four types of display of (circle), (circle), (triangle | delta), and ▲ on a scanning line are the same as FIG.

If the target sample point of interest is represented by?, The color carrier phase is 180 degrees different at four points a, b, c and d before and after the two sample points and one line up and down in the same field n.

Therefore, a line comb filter using a digital circuit or the adaptive YC separation filter described in Japanese Patent Laid-Open No. 58-242367 can be configured.

Further, as shown in Fig. 5A, since the color part carrier phase is 180 degrees different at the same sample point separated by one frame, the YC separation filter between frames can also be configured.

In addition, as can be seen from FIG. 5B, in the n-1 field before the first field from the main sample point of view, the three-point sample points on one line or two sample points under one line are reversed. The calculation of any one of them and the point of interest enables YC separation between fields. In addition, as can be seen from FIG. 5C, in the n + 1 field after one field from the main sample point of view, the three points are reversed before and after the sample point under one line or two sample points on one line. YC separation between fields can be performed by any of the operations and the point of interest.

In addition, the μ-axis, ν-axis, and f that are orthogonal to each other in consideration of the x-axis, the y-axis, and the t-axis, which are orthogonal to each other in consideration of the μ-axis as the horizontal frequency axis, the v-axis as the vertical frequency axis and the f-axis as the time-frequency axis Consider three-dimensional frequency space that can be configured as an axis.

6 shows a projection of the three-dimensional frequency space. FIG. 6 is a view of the three-dimensional frequency space in the inclined direction, FIG. 6 is a view of the three-dimensional frequency space in the negative direction of the f-axis, and FIG. 6 is a definition of the μ-axis in the three-dimensional frequency space. It is the figure seen from the direction.

In Fig. 6, the spectrum distribution of the V signal in the three-dimensional frequency space is shown. As can be seen from FIGS. 6A to 6C, the spectrum of the Y signal is enlarged around the origin of the three-dimensional frequency space, and the spectrum of the C signal is the color-broadcast wave frequency fsc, and the I and Q signals are orthogonal two-phase. Since it is modulated, it is located in the space of four places like FIG.

However, as shown in FIG. 6C, when the V signal is viewed on the μ-axis, the C signal exists only in the second upper limit and the fourth upper limit.

This corresponds to the fact that the solid line representing the in-phase of the color subcarriers in FIG. 5A is rising with time.

Nevertheless, in the past, when the motion of an image is detected, YC separation using correlation in the field is performed. Therefore, band limitation in the μ-axis and ν-axis directions is possible, but band limitation in the f-axis direction is added. I could not.

Therefore, the frequency space in which the Y signal is present is originally separated as the C signal, and the band of the Y signal on the motion screen is narrowed.

Therefore, as described above, by performing YC separation in the inter-field processing, the band of the Y signal in the motion image can be enlarged.

In FIG. 5B, the sample points?, B, and c are located in the n-1 field near the target sample point? And the color carrier phase is 180 °. Further, in the fifth C, the point where the color subcarrier phase is different in the vicinity of the target sample point? In the n + 1 field and the color part carrier phase is 180 ° is a sample point. By combining these operations with any one of six points, YC separation in three fields is possible.

First, it is possible to extract the low frequency component in the three-dimensional frequency space which is a part of the Y signal by the sum of the target sample point? And the sample point? In addition, the difference between the target sample point? And the sample point? Can extract a high frequency component in the three-dimensional frequency space including the C signal, and the C signal can be removed by passing the LPF. Adding these outputs yields a Y signal. The C signal is obtained by subtracting the Y signal from the V signal. This is referred to as YC separation A in three fields.

Figs. 7A to 7C show a three-dimensional frequency space similarly to Figs. 6A to C, and show a frequency space in which the Y signal and the C signal obtained by the YC separation A in the three fields exist.

Second, sample points in Figs. 5A through C. Sample point of interest ◎ and sample point for hemp sample point. By adding the difference between the and the sample point ○ yarn, it is possible to remove the C signal from the high frequency component in the three-dimensional frequency space including the C signal. The Y signal can be obtained by adding a low-pass component in the three-dimensional frequency space, which is a part of the Y signal obtained by adding the target sample point? And the sample point? The C signal is obtained by subtracting the Y signal from the V signal. This is referred to as YC separation B in three fields.

Similarly, FIGS. 8A to 8C also show a frequency space in which the Y and C signals obtained by the YC separation B between fields exist. 8A to C show that some C signals are included in the separated Y signal, but since the Y signal and the C signal have strong correlation with each other, very few C signals are included in the Y signal.

Third, sample point in Fig. 5 B, C Sample point of interest sample ◎ and sample point for bar Sample point similar to positional relationship of ○ ○ Sample point of interest sample point ◎ and sample point By adding the difference between the bar and the sample point o, the C signal can be removed from the high frequency component in the three-dimensional frequency space including the C signal. The Y signal can be obtained by adding a low-pass component in the three-dimensional frequency space, which is a part of the Y signal obtained by adding the target sample point? And the sample point? The C signal is obtained by subtracting the Y signal from the V signal. This is referred to as YC separation C in three fields.

Similarly, Figs. 9A to C also show frequency spaces in which the Y and C signals obtained by the YC separation C between fields exist. 9A to C show that some C signals are included in the separated Y signal, but very few C signals are included in the Y signal for the same reason as in FIG. In order to adaptively control the YC separation between the three types of fields, it is necessary to detect the correlation of the images in the direction in which the target sample point? And the sample point? Thus, the correlation of the image in each direction is detected by arithmetic operations of the sample points in the n-1 field with the target sample point ◎ between the b, d, and n + 1 fields. It is good to use it as a control signal.

Next, the operation of the in-frame YC separation circuit of the configuration shown in FIG. 2 will be described.

The present invention is characterized in that, when the motion detection circuit 80 determines that the image is a motion image, it is the most suitable of the motion image processing, among the three fields YC separation including three kinds of three field operations instead of the YC separation in the field. do.

In FIG. 2, the V signal 101 input from the input terminal 11 is delayed by 262 lines in the 262 line delay circuit 14, delayed by 1 line in the 1 line delay circuit 15, and is delayed by the 262 line delay circuit ( There is a delay of 262 lines in 17) and one line of delay in the one-line delay circuit 18.

The V signal, which is the output of the one-line delay circuit 15, is further delayed by two pixels in the two-pixel delay circuit 20, and the subtractor 25 subtracts the V signal delayed by two pixels in the two-pixel delay circuit 21 by the subtractor 25. The difference between the main store ◎ and the sample store ● is obtained. Passing this through the LPF 26 produces a high frequency component in three-dimensional frequency space from which the C signal for three-field YC separation A is removed.

The V signal 101 input from the input terminal 11 is subtracted from the output of the one line delay circuit 15 and the subtractor 16, and is delayed by one line in the one line delay circuit 19. Ma and sample point ○ We get difference of company. By adding this and the output of the subtractor 25 with the adder 24, a high frequency component in three-dimensional frequency space in which the C signal for YC separation B is removed in three fields is obtained.

In addition, the output of the one-line delay circuit 19 is delayed four pixels in the four-pixel delay circuit 22 to obtain the difference between the sample point? Bar and the sample point? A. By adding this and the output of the subtractor 25 with the adder 23, a high frequency component in three-dimensional frequency space from which the C signal for three-field YC separation C is removed is obtained.

The calculation between the three types of three fields described above is input to the signal selection circuit 39 and is selected by the output of the minimum value selection circuit 38 described below.

The output of the 262 line delay circuit 17 and the output of the four pixel delay circuit 29 are subtracted by the subtractor 32, and are absolute valued by the absolute value circuit 35 so that the sample points in FIGS. Detect the correlation between the die and the bar. The output of the four-pixel delay circuit 30 and the output of the one-line delay circuit 28 are subtracted by the subtractor 33, and are absolute valued by the absolute value circuit 36, and the sample points in Figs. Detect correlation between e The output of the two-pixel delay circuit 21 and the output of the two-pixel delay circuit 31 are subtracted by the subtractor 34, and the absolute value circuit 37 is converted to an absolute value so that the sample points in FIGS. Detect the correlation between a and a.

The minimum value selecting circuit 38 selects the smallest of the three types of absolute value outputs (the relation detection amount is the maximum) to control the signal selecting circuit 39.

That is, the signal selection circuit 39 outputs the output of the adder 23 when the output of the absolute value circuit 35 is minimum, and outputs the adder 24 when the output of the absolute value circuit 36 is minimum. When the output of the absolute value circuit 37 is minimum, the output of the LPF 26 is selected.

In addition, the output of the signal selection circuit 39 adds a low-band component on the three-dimensional frequency space which is the output of the adder 27 to the adder 40 to obtain the YC separated Y signal 112 in three fields.

In addition, the subtractor 41 subtracts the YC separation Y signal 112 in three fields from the V signal output of the two pixel delay circuit 20 to obtain the YC separation C signal 113 in three fields. .

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

FIG. 2 is an adaptive switch that configures a filter that performs the band limiting of the Y signal by three kinds of three fields of operation, while FIG. 3 shows a filter that performs the band limiting of the C signal by three kinds of three fields of operation. Configure and switch adaptively. Only portions in which the band limiting of C signals different from those in FIG. 2 are performed among the YC separation circuits in the three fields of the configuration shown in FIG. In FIG. 3, the same number is written in the place equivalent to FIG.

The output of subtractor 25 passes through BPF 44 to obtain a C signal for YC separation A in three fields.

The subtractor 43 obtains the C signal for the YC separation B in the three fields by subtracting the difference between the sample point? Ma and sample point ○ company from the output of the subtractor 25 from the output of the subtractor 25. Lose.

The subtractor 42 subtracts the difference between the sample point bar and the sample point ○ A from the output of the winding 25 to the C signal for the YC separation C in the three fields. Obtained.

The output of the signal selection circuit 39 can select the C signal by either of three kinds of three-field operations to obtain the YC separated C signal 113 in the three fields.

In addition, the subtractor 45 subtracts the three-field YC separation C signal 113 from the V signal output from the two-pixel delay circuit 20 to obtain the three-field YC separation Y signal 112. .

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

In FIG. 4, the difference between FIG. 2 and FIG. 4 differs from that in the three-field YC separation circuit including three kinds of three-field operations. Of the three-field YC separation circuits in the configuration of FIG. 4, only the inter-frame correlation detection circuits different from FIG. 2 will be described. In FIG. 4, the same number is written in the place equivalent to FIG.

The output of the adder 23 is input to the first input terminal of the signal selection circuit 49. The output of the adder 24 is input to the second input terminal of the signal selection circuit 49. The output of the LPF 26 is input to the third input terminal of the signal selection circuit 49. The output of the two-pixel delay circuit 20 is input to the first input terminals of the subtractors 25, 41 and the adder 27 and to the YC separation circuit 46 in the field. The in-field YC separation circuit 46 is composed of only in-field calculations, similar to the in-field YC separation circuit 4 used in FIG. 10 of the conventional example. The output of the YC separation circuit 46 in the field is input to the fourth input terminal of the signal selection circuit 49.

The output of the absolute value circuit 35 is input to the first input terminal of the maximum value selection circuit 47 and the minimum value selection circuit 38, respectively. The output of the absolute value circuit 36 is input to the second input terminals of the maximum value selection circuit 47 and the minimum value selection circuit 38, respectively. The output of the absolute value circuit 37 is input to the third input terminals of the maximum value selection circuit 47 and the minimum value selection circuit 38, respectively. The output of the maximum value selecting circuit 47 is input to the first input terminal of the threshold value determining circuit 48. The output of the minimum value selecting circuit 38 is input to the second input terminal of the threshold value determination circuit 48 and the fifth input terminal of the signal selection circuit 49. The output of the threshold value determination circuit 48 is input to the sixth input terminal of the signal selection circuit 49. The threshold value determination circuit 48 is a signal selection circuit when the maximum value of the three types of interframe correlation is smaller than the first threshold value α or the minimum value of the three types of interframe correlation is larger than the second threshold value β. Control 49 to select the output of the YC isolation circuit 46 in the field. On the other hand, when the threshold value determination circuit 48 determines that the maximum value of the three types of interframe correlation is larger than the first threshold value α or the minimum value of the three types of interframe correlation is smaller than the second threshold value β, As the output of the minimum value selecting circuit 38, the signal selecting circuit 49 is used for the output of the adder 23 when the output of the absolute value circuit 35 is minimum, and when the output of the absolute value circuit 36 is minimum. When the output of the 24 is the minimum and the output of the absolute value circuit 37 is the minimum, it is controlled to select the output of the LPF 26, respectively. In this case, similarly to the second embodiment, YC separation in three fields including three kinds of inter-field operations is adaptively performed. However, it is assumed that there is a relationship of α <β.

Also in the embodiment of FIG. 3, in-field band using the in-field YC separation circuit 46, the maximum value selection circuit 47, the threshold value determination circuit 48, and the signal selection circuit 49 similarly to FIG. It is possible to adaptively control the YC separation by limitation only and the YC separation in three kinds of three fields.

As described above, according to the present invention, the following effects can be obtained in the three-field YC separation circuit at the time of detecting the motion image by the motion detection circuit.

(1) Three kinds of YC separated filters for performing the band limit of the luminance signal by locally detecting the correlation between the frames and performing three kinds of three fields, or four kinds including the band limitation of the luminance signal by the intrafield calculation. The YC separation filter in the three-field field can be adaptively switched. Therefore, in the motion conversion processing of the motion adaptive YC separation filter, the optimal YC separation is possible by using the image correlation. A motion adaptive YC separation filter that performs YC separation can be configured.

(2) Four types including the three-field YC separation filter which locally detects the correlation between frames and limits the band of the color signal by only three kinds of three fields, or the band limitation of the color signal by the fields. Since the YC separation filter in the three fields is configured to be switched adaptively, the optimal YC separation is possible by using the image correlation in the motion image processing in the motion adaptive YC separation filter. It is possible to construct a motion adaptive YC separation filter that executes YC fundamentals with less degradation.

Claims (2)

A circuit for separating a luminance signal and a color signal from a composite color television signal in which a color signal is frequency-multiplexed in a high frequency region of a luminance signal, comprising: a motion detection circuit for locally detecting image movement using a correlation between frames; When the circuit detects a still picture, the inter-frame luminance signal color signal separation luminance signal and the inter-frame luminance signal color signal separation luminance signal and the inter-frame luminance signal color signal separation color signal are outputted by performing the separation of the luminance signal and the color signal using the inter-frame correlation. When the detection circuit detects a motion image, the correlation is detected locally by the difference in the phases of the color carriers between the frames, and the detection result adapts the inter-field processing including calculation between three fields. 3rd field luminance signal color signal A three-field grayscale signal color signal separation circuit for outputting a luminance signal and a three-field luminance signal color signal separation color signal, and a separation between the luminance signal color signal separation luminance signal and the three-field luminance signal color signal according to the output of the motion detection circuit. A luminance signal mixing circuit for outputting a motion adaptive luminance signal color signal separated luminance signal by mixing a luminance signal, and mixing the luminance signal color signal separated color signal between the frame and the luminance signal color signal separated color signal in the three fields according to the output of the motion detection circuit; A motion adaptive luminance signal color signal separation filter comprising a color signal mixing circuit for outputting a color signal separation color signal. 2. The method according to claim 1, wherein when the motion detection circuit detects a motion image instead of the luminance signal color signal separation circuit in the three fields, a correlation is obtained locally by obtaining a difference at the point where the phase of the color subcarrier is the same between frames. The detection result is performed to adaptively switch between the inter-field processing and the one-field processing including the inter-field calculation based on the detection result, so that the three-field luminance signal color signal separated color signal and the three-field luminance signal are executed. A motion adaptive luminance signal color signal separation filter replaced with a luminance signal color signal separation circuit in three fields for outputting a color signal separation luminance signal.

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