JP4219924B2 - Motion detection circuit and luminance signal color signal separation circuit - Google Patents

Description

  The present invention relates to a motion detection circuit and an adaptive 3D luminance signal color signal separation circuit including the motion detection circuit.

  Conventional motion detection circuits require a large capacity memory. For example, an NTSC three-dimensional YC separation circuit generally requires two frames of memory, and a PAL three-dimensional YC separation circuit generally uses four frames of memory. In order to reduce the cost of the system, it is desirable to reduce the size of the required memory.

  As an example of the prior art in which the memory scale is reduced, a first frame memory for delaying the input NTSC composite video signal by one frame and a second frame for delaying the output signal of the first frame memory by one frame. In the writing to the second frame memory, the RY signal and the BY signal among the output signals of the first frame memory are alternately written for each line. There is a frame memory whose capacity is halved (see, for example, Patent Document 1). Further, the chroma correlation is detected from the comparison between the difference between the lines of the composite video signal and a predetermined threshold, the chroma correlation is detected from the comparison between the difference between the lines of the signal delayed by one frame period and the predetermined threshold, and the difference between them. When the difference between frames is smaller than a predetermined threshold value, the motion detection signal is forcibly made zero. By using such a configuration, one frame is calculated. There is also known a technique that makes it possible to perform three-dimensional YC separation with this memory (see, for example, Patent Document 2).

JP-A-5-276537 (5th page, FIG. 1) Japanese Patent Laid-Open No. 9-46726 (page 14, FIG. 1)

However, the technique described in Patent Document 1 requires a total of 1.5 frames of memory, as can be seen from the above description, and particularly as shown in FIG.
On the other hand, with the technique described in Patent Document 2, the memory capacity may be one frame, but there is a problem that the detection performance is low because motion detection is performed by chroma correlation.

  An object of the present invention is to realize motion detection without reducing the detection performance while reducing a large-capacity memory necessary for realizing a three-dimensional YC separation circuit.

The motion detection circuit of the present invention includes:
A composite color television signal and a delay signal obtained by delaying the composite color television signal by one frame period or two frame periods are input, a difference between the composite color television signal and the delay signal is calculated, and a difference representing the difference is calculated. A differential operation circuit for outputting a signal;
A low-pass filter that extracts a low-frequency component below the color subcarrier frequency from the difference signal output from the difference calculation circuit;
A band-pass filter that extracts a frequency component near the color subcarrier frequency from the difference signal output from the difference calculation circuit;
A high-frequency luminance component extraction circuit that receives the composite color television signal and the delayed signal as input and extracts a high-frequency luminance component;
A motion detection signal generation circuit that outputs a motion detection signal by combining the output signal of the low-pass filter and the output signal of the band-pass filter;
The high-frequency luminance component extraction circuit is
A frame stillness determination circuit that receives the frame of the composite color television signal and the frame of the delayed signal as input, and detects stillness of the luminance signal between the frames,
A color subcarrier frequency detection circuit for detecting an oblique fringe component composed of a luminance signal near the color subcarrier frequency;
A synthesis circuit that synthesizes the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency detection circuit;
The output signal of the frame stillness determination circuit becomes a signal having a larger value as the degree of stillness between the composite color television signal and the delayed signal increases.
The output signal of the color subcarrier frequency component detection circuit becomes a signal having a larger value as the color subcarrier frequency component increases,
The synthesis circuit outputs a signal having a larger value of the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency component detection circuit as a signal representing the high-frequency luminance component,
The motion detection signal generation circuit includes:
When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit is less than or equal to a predetermined threshold value, the larger one of the output signal value of the low-pass filter and the output signal value of the band-pass filter A signal having the same value as is output as the motion detection signal,
When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit has a value larger than the threshold value, the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter the same value is the larger, the signal having a value obtained by multiplying a coefficient smaller than 1 or the value of the signal is zero, you and outputs as the motion detection signal.

  According to the motion detection circuit of the present invention, the high-frequency luminance component is extracted and the motion detection result is output based on the high-frequency luminance component. In this case, motion detection can be performed with a memory having a half capacity normally used, such as for two frames, and detection with little cross color and dot interference can be performed.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a motion detection circuit 10 according to Embodiment 1 of the present invention. The illustrated motion detection circuit 10 detects the motion of an NTSC composite color television signal, and includes a difference calculation circuit 11, a low-pass filter (LPF) 12, a band-pass filter (BPF) 13, and a high-frequency signal. A luminance component extraction circuit 14 and a motion detection signal generation circuit 15 are included.

The difference calculation circuit 11 receives a composite color television signal VS0 and a signal (1 frame delay signal) VS1 obtained by delaying the composite color television signal by one frame period, and inputs a composite color television signal (“0 frame delay signal”). The difference between VS0 and 1-frame delay signal VS1 is calculated. The LPF 12 extracts a low-frequency component (a component in a frequency region lower than the color subcarrier frequency) from the difference signal output from the difference calculation circuit 11. The BPF 13 extracts a color subcarrier frequency component from the difference signal output from the difference calculation circuit 11.
The high frequency luminance component extraction circuit 14 receives the composite color television signal VS0 and the delay signal VS1, and extracts a high frequency luminance component.
The motion detection signal generation circuit 15 receives the output signal of the LPF 12 and the output signal of the BPF 13, and generates and outputs a motion detection signal MF based on the output of the high frequency luminance component extraction circuit 14.

FIG. 2 is a block diagram showing an example of the high-frequency luminance component extraction circuit 14 in the motion detection circuit 10 of FIG. The high-frequency luminance component extraction circuit 14 includes an interframe stillness determination circuit 40, a color subcarrier frequency component detection circuit 50, and a synthesis circuit 55.
The interframe stillness determination circuit 40 includes a difference calculation circuit 41, an absolute value circuit 42, a determination circuit 43, and an isolated point removal circuit 44.
The color subcarrier frequency component detection circuit 50 includes a horizontal / vertical band pass filter 51, an absolute value circuit 52, and a horizontal enlargement circuit 53.
The synthesis circuit 55 synthesizes the output signal of the frame stillness determination circuit 40 and the output signal of the color subcarrier frequency component detection circuit 50.

  In the motion detection circuit 10 according to the first embodiment, the composite color television signal VS0 and the one-frame delay signal VS1 are input and input to the difference calculation circuit 11 and the high frequency luminance component extraction circuit 14. The output of the difference calculation circuit 11 is input to the LPF 12 and the BPF 13. The output signal of the LPF 12 and the output signal of the BPF 13 are input to the motion detection signal generation circuit 15 as motion components, and the motion detection signal generation circuit 15 receives the output signal VL of the LPF 12 and the output signal VB of the BPF 13 as inputs, The output signal HY of the component extraction circuit 14 is below a certain threshold value HYt, and one of its two input signals (LPF 12 output and BPF 13 output) VL and VB values α and β is greater than 0 (α> 0 or When β> 0), the output signal MF is synthesized so as to have a value greater than 0 (γ> 0), and when the output signal HY of the high-frequency luminance component extraction circuit 14 has a value greater than the threshold value HYt. The value of the output signal MF is smaller than the value (γ) obtained by combining the values of the two input signals VL and VB as described above (δ <γ), for example, 1 A value obtained by multiplying a smaller coefficient kr (δ = kr × γ) or 0.

For example, as shown in FIG. 3, the motion detection signal generation circuit 15 selects and outputs the larger one of the output signal VL of the LPF 12 and the output signal VB of the BPF 13 (MAX (VL, VB)). The output signal HY of the circuit 16 and the high-frequency luminance component extraction circuit 14 is compared with a predetermined threshold value HYt, and the comparison circuit 17 that outputs the coefficient ka according to the comparison result is compared with the output of the maximum value circuit 16. And a multiplier 18 that multiplies the coefficient ka from the circuit 17.
When the output signal HY of the high-frequency luminance component extraction circuit 14 is equal to or less than the threshold value HYt, the coefficient ka output from the comparison circuit 17 is “1”, and the output of the multiplier 18 is equal to the output of the maximum value circuit 16. .
When the output signal HY of the high-frequency luminance component extraction circuit 14 is larger than the threshold value HYt, the coefficient ka output from the comparison circuit 17 is a value kr smaller than “1”, and the output of the multiplier 18 is the maximum value circuit. 11 is multiplied by the coefficient kr. When the coefficient kr is set to “0”, the output of the multiplier 18 becomes “0”. In this way, the comparison circuit 17 and the multiplier 18 constitute means for changing the output of the maximum value circuit 16 in accordance with the output signal HY of the high-frequency luminance component extraction circuit 14.
When the output signal HY of the high-frequency luminance component extraction circuit 14 is a 1-bit signal, when the signal HY is “0”, the coefficient ka output from the comparison circuit 17 is set to “1”, and the signal HY Is “1”, the coefficient ka output from the comparison circuit 17 is set to a value kr smaller than 1. kr may be set to “0”.

  The output signal MF of the motion detection signal generation circuit 15 is output as an output signal of the motion detection circuit 10.

  The high-frequency luminance component extraction circuit 14 receives the composite color television signal VS0 and the signal VS1 delayed by one frame period. The input signal VS0 and the one-frame delay signal VS1 Input to the subcarrier frequency component detection circuit 50.

  In the inter-frame stillness determination circuit 40, the difference calculation circuit 41 calculates a difference value of the two input signals and outputs the difference value to the absolute value circuit 42. The absolute value circuit 42 converts the input signal (output of the difference calculation circuit 41) into an absolute value. The difference calculation circuit 41 and the absolute value circuit 42 constitute a difference absolute value calculation circuit 46 that calculates the absolute value of the difference value of the two input signals.

  The output of the difference absolute value calculation circuit 46 (output signal of the absolute value circuit 42) DZ is supplied to the determination circuit 43. In the determination circuit 43, when the output signal DZ of the difference absolute value calculation circuit 46 is smaller than a predetermined threshold value DZt, a relatively large level (a large value within a range of values that the output signal JG of the determination circuit 43 can take, for example, If the output signal DZ of the absolute value calculating means 46 is equal to or greater than the above threshold value, it is relatively small (small within the range of values that the output signal JG of the determination circuit 43 can take). A signal JG having a value (for example, a value smaller than the above threshold) is output.

The isolated point removal circuit 44 removes isolated points in the output of the determination circuit 43. For example, the isolated point removal circuit 44 may detect the signal before and after the target pixel in the horizontal direction even if the signal JG (target pixel signal) JG output from the determination circuit 43 is a relatively large level signal. When the pixel signal is a relatively small level signal, the signal of the target pixel is changed to the relatively small level.
The output signal SF of the isolated point removal circuit 44 is output to the synthesis circuit 55 as an output signal of the interframe stillness determination circuit 40.

In the color subcarrier frequency component detection circuit 50, the horizontal / vertical band pass filter 51 filters the input signal in the horizontal direction and the vertical direction, and outputs the filtered signal to the absolute value circuit 52.
The absolute value circuit 52 converts the signal into an absolute value and outputs it to the horizontal enlargement circuit 53.

The horizontal enlargement circuit 53 enlarges the output of the absolute value circuit 52 in the horizontal direction. For example, in the horizontal enlargement circuit 53, even if the output signal (signal of the target pixel) EZ of the absolute value circuit 52 is a signal having a relatively small level, the signal of the pixel before or after in the horizontal direction is relatively high. The output signal (the signal of the target pixel) is set to a relatively large level.
The output signal CS of the horizontal enlargement circuit 53 is output to the synthesis circuit 55 as an output signal of the color subcarrier frequency component detection circuit 50.

  The synthesizing circuit 55 uses the output signal SF of the inter-frame stillness determination circuit 40 and the output signal CS of the color subcarrier frequency component detection circuit 50 as input signals, and a relatively large value ( In the case where the output signal SF of the interframe stillness determination circuit 40 or the output signal CS of the color subcarrier frequency component detection circuit 50 takes a large value within a range of possible values (for example, a value larger than a predetermined threshold value) The output signal is set to a relatively large value (a large value within a range of values that can be taken by the output signal HY of the synthesis circuit 55, for example, a value larger than a predetermined threshold).

  The synthesizing circuit 55 receives, for example, the output signal SF of the inter-frame stillness determination circuit 40 and the output signal CS of the color subcarrier frequency component detection circuit 50, and selects the larger one (MAX (SF, CS)). The maximum value circuit to be output. When the output signal SF of the interframe stillness determination circuit 40 and the output signal CS of the color subcarrier frequency component detection circuit 50 are 1-bit signals, the above maximum value circuit is configured by an OR circuit.

  As described above, the motion detection circuit of FIG. 1 is compatible with the NTSC system, and the difference calculation circuit 11 extracts a low-frequency component from the output signal obtained by taking the difference of the input signal of one frame difference by the LPF 12. Thus, it can be handled as a motion component of the luminance signal. On the other hand, in a normal NTSC system motion detection circuit, a color signal motion component that supplements the luminance signal motion component can be obtained by taking the difference between the input signals of two frame differences. However, as shown in FIG. In the motion detection circuit with a reduced number of signals, an input signal delayed by 2 frames cannot be obtained. Therefore, the color signal motion is extracted by extracting the color color subcarrier frequency component from the 1-frame difference signal by the BPF 13 instead. Getting ingredients.

  However, in the case where the color subcarrier frequency component is extracted from the one frame difference signal by the BPF 13 instead of the two frame difference signal, a luminance signal in the vicinity of the color subcarrier frequency, that is, an oblique fringe signal is present in the input signal. In this case, it is erroneously detected as a motion signal. In order to prevent this, when the high-frequency luminance component extraction circuit 14 detects a luminance signal near the color subcarrier frequency, the motion detection signal generation circuit 15 is controlled to reduce the motion detection signal MF.

  The determination circuit 43 outputs a relatively large level signal when the absolute value of the inter-frame difference signal is equal to or less than a certain threshold value DZt. Also, the isolated point removal circuit 44 outputs a signal having a relatively small level comparable to that of the preceding and succeeding pixels when each pixel becomes a signal having a level larger by one point than the preceding and succeeding pixels. It is. For example, the level is changed to the same level as the previous pixel, the same level as the subsequent pixel, or the same level as the larger one of the previous pixel and the subsequent pixel. As a result, the output of the inter-frame stillness determination circuit 40 outputs a relatively large level signal when a static luminance signal is input, and outputs an inter-frame difference signal when a static color signal is input. Since the absolute value is relatively large, a relatively small level signal is output.

In the color subcarrier frequency component detection circuit 50, the horizontal / vertical bandpass filter 51 filters the input signal in the horizontal direction and the vertical direction, so that the color subcarrier frequency component including a luminance signal that forms diagonal stripes is obtained. The absolute value is extracted and converted into an absolute value by the absolute value circuit 52.
Therefore, the color subcarrier frequency component detection circuit 50 outputs a relatively large level signal when the color subcarrier frequency component is detected.
Therefore, when a still luminance signal is input by the interframe stillness determination circuit 40 and the color subcarrier frequency component detection circuit 50, or when a luminance signal having an oblique stripe is input, the high frequency luminance component extraction circuit 14 Is a signal having a relatively large level (a large value within a range of values that the output signal HY of the high-frequency luminance component extraction circuit 14 can take, for example, a value larger than a predetermined threshold).
When the output signal of the high-frequency luminance signal component extraction circuit 14 is a 1-bit (binary) signal, the “large level” is “1” and the “small level” is “0”.

For example, when the number of output bits of the high-frequency luminance component extraction circuit 14 is 1, when it is determined that a static luminance signal has been input, or when a luminance signal that has an oblique stripe is input, “1”. In this case (when “1” is output), the motion signal MF that is the output of the motion detection signal generation circuit 15 has a low level even if the outputs of the LPF 12 and the BPF 13 are relatively large. Signal or “0” level signal.
Further, when the number of output bits of the high-frequency luminance component extraction circuit 14 is a plurality of bits, when it is determined that a stationary luminance signal has been input, or when it has been determined that a luminance signal having an oblique stripe has been input. The high-frequency luminance component extraction circuit 14 has a large value corresponding to the magnitude of the output signal SF and CS of the output signal SF and CS of the interframe stillness determination circuit 40 and / or the color subcarrier frequency component detection circuit 50 (signals SF and CS are In this case, the motion signal MF that is the output of the motion detection signal generation circuit 15 is output from the high-frequency luminance component extraction circuit 14 even when the outputs of the LPF 12 and the BPF 13 are large. In accordance with the output HY (as the output signal HY of the high-frequency luminance component extraction circuit 14 is larger), the signal is gradually reduced in level.

Hereinafter, the operation of the determination circuit 43, the isolated point removal circuit 44, the horizontal enlargement circuit 53, and the synthesis circuit 55 will be described in more detail separately.
As described above, the determination circuit 43 of the inter-frame stillness determination circuit 40 is at a relatively large level when the output signal DZ of the absolute value circuit 42 is smaller than a certain threshold value DZt, and the output signal DZ of the absolute value circuit 42 is If it is equal to or greater than the threshold value DZt, a signal having a relatively small level is output.

When the determination circuit 43 outputs a signal having three or more values, for example, a 2-bit (four-value) signal, the relationship between the input signal value and the output signal value of each pixel is, for example, as shown in FIG. Yes, when the input signal (output of the absolute value circuit 42) DZ is equal to or greater than the predetermined threshold value DZt, the output JG of the determination circuit 43 is “0”, and the input signal (output of the absolute value circuit 42) is the above threshold value DZt. In a smaller range, the output signal JG of the determination circuit 43 has a magnitude corresponding to the distance of the output DZ of the absolute value circuit 42 from the threshold DZt (the output DZ of the absolute value circuit 42 and the threshold DZt). The larger the difference, the greater the value).
When the determination circuit 43 outputs a binary signal, that is, a 1-bit signal, the relationship between the input signal value of each pixel and the output signal value is, for example, as shown in FIG. When the output DZ of the absolute value circuit 42) is equal to or greater than the predetermined threshold DZt, the output JG of the determination circuit 43 is “0”, and the input signal (output of the absolute value circuit 42) DZ is smaller than the threshold DZt. The output signal JG of the determination circuit 43 is “1”.

When the determination circuit 43 outputs a signal of three or more values, for example, a 2-bit (4-value) signal, the relationship between the column of the input signal JG and the column of the output signal SF of the isolated point removal circuit 44 is, for example, This is as shown in FIGS. 6 (a) and 6 (b). In FIG. 7 and FIG. 7 to FIG. 9 described later, a dotted line extending in the vertical direction indicates a break between the signal of each pixel and the signal of the next pixel. When the signal JG of each pixel (pixel of interest) output from the determination circuit 43 is larger than the threshold value JGt, and the signals (outputs of the determination circuit 43) JG of the surrounding pixels are all equal to or less than the threshold value JGt The target pixel is set to the same value as the surrounding pixels (for example, the previous pixel or the subsequent pixel). 6A and 6B, when both the previous pixel and the subsequent pixel are equal to or less than the threshold value, the same value as the largest of the previous pixel and the subsequent pixel is set. Instead of doing so, it may be the same value as the previous pixel or the same value as the subsequent pixel. Further, it may be set to the same value as the threshold value JGt.
When the determination circuit 43 outputs a binary signal, that is, a 1-bit signal, the relationship between the column of the input signal JG and the column of the output signal SF of the isolated point removal circuit 44 is, for example, FIG. And as shown in (b), the signal DZ of each pixel (target pixel) output from the determination circuit 43 is “1”, and the signals DZ of the surrounding pixels (output of the determination circuit 43) are all “0”. In the case of “,” the signal of the target pixel is set to “0”.

When the output signal of the absolute value circuit 52 is a signal having three or more values, for example, a 2-bit (4-value) signal, the relationship between the input signal sequence and the output signal sequence of the horizontal enlargement circuit 53 is, for example, FIG. As shown in a) and (b), the signal EZ of each pixel (target pixel) output from the absolute value circuit 52 is smaller than the threshold value EZt, and the signal of the surrounding pixels (output of the absolute value circuit 52) If any of EZ is equal to or greater than threshold EZt, the value of the surrounding pixel (for example, the previous pixel or the subsequent pixel) is set as the value of the target pixel. 8A and 8B, when the values of the previous pixel and the subsequent pixel are both equal to or greater than the threshold value EZt, the same value as the smallest one of the previous pixel and the subsequent pixel is set. Instead of doing so, it may be the same value as the previous pixel or the same value as the subsequent pixel. Moreover, it is good also as setting it as the same value as said threshold value EZt.
When the output signal of the absolute value circuit 52 outputs a binary signal, that is, a 1-bit signal, the relationship between the input signal sequence and the output signal sequence of the horizontal enlargement circuit 53 is, for example, FIG. ) And (b), the signal EZ of each pixel (pixel of interest) output from the absolute value circuit 52 is “0”, and the signal of the surrounding pixels (output of the absolute value circuit 52) EZ If any one is “1”, the signal of the target pixel is set to “1”.

  As described above, the synthesizing circuit 55 uses the output signal SF of the interframe stillness determination circuit 40 and the output signal CS of the color subcarrier frequency component detection circuit 50 as input signals, and uses either one of the two input signals. When taking a relatively large value, the output signal HY is set to a relatively large value.

  As described above, the motion detection signal generation circuit 15 receives the output signal VL of the LPF 12 and the output signal VB of the BPF 13 as input, and the output signal HY of the high-frequency luminance component extraction circuit 14 is equal to or less than a certain threshold value HYt, and the two When one of the values α and β of the input signals VL and VB is greater than 0 (α> 0 or β> 0), the output signal MF is synthesized so as to have a value greater than 0 (γ> 0) When the output signal HY of the luminance component extraction circuit 14 has a value larger than the threshold value HYt, the value of the output signal MF is obtained from the result of combining the two input signals VL and VB as described above. Is also a small value (δ <γ) or 0.

The output MF of the motion detection signal generation circuit 15 is used as a motion detection signal.
By such an operation, when the high-frequency luminance component extraction circuit 14 detects a luminance signal near the color subcarrier frequency, by reducing the motion detection signal MF, a luminance signal near the color subcarrier frequency, that is, an oblique fringe When a signal is included in the input signal, it is prevented from being erroneously detected as a motion signal.

A coefficient multiplier that multiplies the signals VL and VH by different coefficients ka and kb, respectively, is inserted on the input side of the maximum value circuit 16 in FIG. 3, and outputs of the coefficient multipliers ka × VL and kb × VB in the maximum value circuit. The larger one (MAX ((ka × VL), (kb × VB)) may be obtained.
Further, an adder circuit may be used instead of the maximum value circuit 16. In this case, a coefficient multiplier may be provided on the input side.
Further, a subtracting circuit is provided instead of the multiplier 18 without providing the comparison circuit 17, and a value corresponding to the output signal HY of the high frequency luminance component extraction circuit 14 is obtained from the output of the maximum value circuit 16 (or addition circuit). You may make it subtract. Even in such a configuration, when the output signal HY of the high-frequency luminance component extraction circuit 14 is a 1-bit signal, when the signal HY is “0”, no subtraction is performed in the subtraction circuit (“0”). When the signal HY is “1”, the subtraction circuit may subtract a predetermined value. In such a configuration, the subtracting circuit is configured to change the output of the maximum value circuit 16 (or the adding circuit) in accordance with the output signal HY of the high-frequency luminance component extracting circuit 14.

Further, as described above, instead of configuring the synthesis circuit 55 only by the maximum value circuit, a coefficient multiplier that multiplies the output signal SF of the interframe stillness determination circuit 40 by the coefficient kd on the input side of the maximum value circuit, and a color A coefficient multiplier that multiplies the output signal CS of the subcarrier frequency component detection circuit 50 by the coefficient ke is inserted, and the maximum value of the outputs (kd × SF, ke × CS) of these coefficient multipliers is calculated by the maximum value circuit. You may make it ask.
An adder circuit may be provided instead of the maximum value circuit. Also in this case, a coefficient multiplier may be inserted on the input side.

Embodiment 2. FIG.
FIG. 10 is a block diagram showing a luminance signal color signal separation circuit according to Embodiment 2 of the present invention.
The illustrated luminance signal color signal separation circuit separates the luminance signal and the color signal of the NTSC composite color television signal VS0, and includes a one-frame delay circuit 3, a two-dimensional color signal extraction circuit (2D filter) 2, The motion detection circuit 10, the difference calculation circuit 4, the selection unit 5, and the difference calculation circuit 6 are included.

The composite color television signal VS0 input to the luminance signal color signal separation circuit is input to the 1-frame delay circuit 3, the 2D filter 2, the motion detection circuit 10, and the difference calculation circuit 6.
The 1-frame delay circuit 3 outputs the composite color television signal VS0 with a delay of one frame period, and is composed of, for example, a memory having a capacity of one frame. The output signal of the 1-frame delay circuit 3 is input to the difference calculation circuit 4 and the motion detection circuit 10.

The 2D filter 2 extracts a color signal based on the calculation of pixel signals in the same field.
The output signal of the 2D filter 2 is input to the selection unit 5. The difference calculation circuit 4 extracts a color signal by subtracting the one-frame delay signal from the composite color television signal. The three-dimensional color signal extraction circuit 7 includes the one-frame delay circuit 3 and the difference calculation circuit 4. Is configured. The output signal of the difference calculation circuit 4 is input to the selection means 5. The difference calculation circuit 6 constitutes a luminance signal extraction circuit.

As the motion detection circuit 10, the motion detection circuit of the first embodiment shown in FIG. 1 is used, and the output of the 1 frame delay circuit 3 is input to the motion detection circuit 10 as the 1 frame delay signal VS1 described above. .
A signal MF indicating the motion detection result output from the motion detection circuit 10 is sent to the selection means 5. The selection unit 5 selects and outputs either the output of the 2D filter 2 or the output of the difference calculation circuit 4 based on the signal MF indicating the motion detection result output from the motion detection circuit 10. Specifically, when the signal MF indicating the motion detection result is larger than a predetermined threshold (indicating that the motion is large, that is, that it is a moving image), the output of the difference calculation circuit 4 is selected to detect motion. When the signal MF indicating the result is small (indicating that the motion is small, that is, a still image), the output of the 2D filter 2 is selected.
The output signal of the selection means 5 is output as a color (C) signal output of the luminance signal color signal separation circuit and is input to the difference calculation circuit 6. In the difference calculation circuit 6, the output signal obtained by subtracting the output of the selection means 5 from the composite color television signal VS0 is output as the luminance (Y) signal output of the luminance signal color signal separation circuit.

  The motion detection circuit 10 in the luminance signal color signal separation circuit according to the second embodiment operates in the same manner as in the first embodiment. In the NTSC system, in order to detect a motion by obtaining a two-frame difference signal in which the phase of the carrier color signal is the same phase, two 1-frame delay circuits are usually required, and the one-frame delay circuit is a luminance signal color signal separation circuit. However, in the present embodiment, the high-frequency luminance component extraction circuit 14 prevents erroneous detection of motion, so that the high-frequency luminance component is erroneously detected as color movement. Accurate luminance signal color signal separation can be performed.

Embodiment 3 FIG.
FIG. 11 shows a motion detection circuit according to the third embodiment of the present invention. The motion detection circuit shown in the figure is the same as the motion detection circuit shown in FIG. 1 except that a composite color television signal VS0 and a signal (two-frame delay signal) VS2 obtained by delaying the composite color television signal for two frame periods. It differs in that it is input.

  The high-frequency luminance component extraction circuit 14 in FIG. 11 is configured as shown in FIG. 12, for example. The high-frequency luminance component extraction circuit 14 shown in FIG. 12 is generally the same as that shown in FIG. 2, but the difference calculation circuit 41 obtains the difference between the composite color television signal VS0 and the two-frame delay signal VS2. It is different.

  In the PAL system, motion detection is performed by obtaining a 4-frame difference signal in which the phase of the carrier color signal is the same phase. Therefore, in the NTSC system, instead of using the 1-frame delay signal VS1, the 2-frame delay signal VS2 is used. Is used.

Embodiment 4 FIG.
FIG. 13 is a block diagram showing a luminance signal color signal separation circuit according to Embodiment 4 of the present invention.
The degree signal color signal separation circuit shown is for separating the luminance signal and the color signal of the PAL composite color television signal and is generally the same as that shown in FIG. Instead of the delay circuit 3 and the motion detection circuit 10, a 2D filter 2A, a 2-frame delay circuit 3A, and a motion detection circuit 10a are provided, and instead of the 1-frame delay signal VS1, the difference calculation circuit 4 and the motion detection circuit 10 are provided. The difference is that a two-frame delay signal VS2 is supplied. The two-frame delay means 3A and the difference calculation circuit 4 constitute the three-dimensional color signal extraction circuit 7 of the fourth embodiment.
As the motion detection circuit 10, the motion detection circuit of the third embodiment shown in FIG. 11 is used, and the output of the 2-frame delay circuit 3A is input to the motion detection circuit 10a as the above-described 2-frame delay signal VS2. .

  In the PAL system, in order to detect motion by obtaining a 4-frame difference signal having the same phase of the carrier color signal, two 2-frame delay circuits are usually required, and the 2-frame delay circuit (3A) is used as the luminance signal color. If one configuration is used for the signal separation circuit, a high-frequency luminance component is erroneously detected as a color motion, but in this embodiment, the high-frequency luminance component extraction circuit 14 prevents erroneous detection of motion detection. Thus, accurate luminance signal color signal separation can be performed.

Embodiment 5 FIG.
FIG. 14 is a block diagram showing a motion detection circuit according to the fifth embodiment of the present invention.
The motion detection circuit shown in the figure is generally the same as the motion detection circuit shown in FIG. 11, but a high-frequency luminance component extraction circuit 14A is provided instead of the high-frequency luminance component extraction circuit 14 in FIG. Not only the composite color television signal VS0 and the 2-frame delay signal VS2 but also the 1-frame delay signal VS1 are input to the component extraction circuit 14A.
FIG. 15 is a diagram illustrating an example of the high-frequency luminance component extraction circuit 14A in FIG. The high-frequency luminance component extraction circuit 14A shown in the figure is generally the same as the high-frequency luminance component extraction circuit 14 in FIG. 12, but instead of the difference calculation circuit 41, the absolute value circuit 42, and the determination circuit 43, a difference calculation unit 61, The difference is that an absolute value conversion unit 62 and a determination circuit 63 are provided.

FIG. 16 is a block diagram showing an example of the inter-frame stillness determination circuit 40A in the high-frequency luminance component extraction circuit 14A of FIG. The inter-frame stillness determination circuit 40 </ b> A includes a difference calculation unit 61, an absolute value conversion unit 62, a determination circuit 63, and an isolated point removal circuit 44.
The difference calculation unit 61 includes a first difference calculation circuit 61a, a second difference calculation circuit 61b, and a third difference calculation circuit 61c, and the absolute value conversion unit 62 includes a first absolute value circuit 62a. And a second absolute value circuit 62b and a third absolute value circuit 62c. The determination circuit 63 has a maximum value circuit 64 and a comparison circuit 65.

  The first difference calculation circuit 61a calculates and outputs the difference value between the composite color television signal (0 frame delay signal) VS0 and the 1 frame delay signal VS1, and the second difference calculation circuit 61b outputs the 0 frame delay signal VS0. The third difference calculation circuit 61c calculates and outputs a difference value between the 1-frame delay signal VS1 and the 2-frame delay signal VS2.

  The first absolute value circuit 62a converts the output of the first difference calculation circuit 61a into an absolute value, the second absolute value circuit 62b converts the output of the second difference calculation circuit 61b into an absolute value, and outputs a third absolute value. The value circuit 62c converts the output of the third difference calculation circuit 61c into an absolute value.

  The first difference calculation circuit 61a and the first absolute value circuit 62a constitute a first difference absolute value calculation circuit that calculates the absolute value of the difference value between the composite color television signal VS0 and the one-frame delay signal VS1. The second difference calculation circuit 61b and the second absolute value circuit 62b constitute a second difference absolute value calculation circuit that calculates the absolute value of the difference value between the composite color television signal VS0 and the two-frame delay signal VS2. The third difference calculation circuit 61c and the third absolute value circuit 62c constitute a third difference absolute value calculation circuit that calculates the absolute value of the difference value between the 1-frame delay signal VS1 and the 2-frame delay signal VS2. Has been.

The maximum value circuit 64 selects and outputs the maximum one of the outputs of the absolute value conversion circuits 62a to 62c.
When the output signal MX of the maximum value circuit 64 is smaller than a predetermined threshold value MXt, the comparison circuit 65 has a relatively large level (a large value within a range of values that the output signal JG of the comparison circuit 65 can take, for example, a predetermined value). If the output signal MX of the maximum value circuit 64 is equal to or greater than the above threshold value, a relatively small level (a value that is small in the range of values that the output signal JG of the comparison circuit 65 can take, for example, A signal JG having a value smaller than a predetermined threshold value is output.

  The relationship between the input signal MX and the output signal JG of each pixel of the comparison circuit 65 is the same as that described for the determination circuit 43 with reference to FIGS. However, the signal DZ and the threshold value DZt should be replaced with the signal MX and the threshold value MXt.

In the inter-frame stillness determination circuit 40A of FIG. 16, for example, the difference calculation circuit 61a, the difference calculation circuit 61b, and the three difference calculation circuits 61c are provided in contrast to the inter-frame stillness determination circuit 40 (FIG. 2) in the first embodiment. the outputs three kinds of frame difference signal, Ri by that having three absolute value circuits 62a and absolute value circuit 62b and the absolute value circuit 62c, and outputs the three kinds of absolute value signals, the maximum value circuit 64 This is input to a determination circuit 63 having a comparison circuit 65. As a result, the absolute value of the frame difference signal used for the interframe stillness determination has increased, so that a more accurate stillness determination can be performed.

Embodiment 6 FIG.
FIG. 17 is a block diagram showing a luminance signal color signal separation circuit according to Embodiment 6 of the present invention. The degree signal color signal separation circuit shown is for separating the luminance signal and the color signal of the PAL composite color television signal and is generally the same as that shown in FIG. Instead, first and second one-frame delay circuits 31 and 32 are provided, and the motion detection circuit shown in FIG. 14 is provided as the motion detection circuit 10, and the composite color television signal VS0 and the two-frame delay signal VS2 are provided. Not only the 1-frame delay signal VS1 but also the high-frequency luminance component extraction circuit 14A of the motion detection circuit 10 is supplied.
As the high-frequency luminance component extraction circuit 14A in the motion detection circuit 10 shown in FIG. 17, for example, the one described with reference to FIGS. 15 and 16 is used.

  As described in the fifth embodiment, in the interframe stillness determination circuit 40A in FIG. 16, for example, the difference calculation circuit 61a and the difference calculation circuit 61b are different from the interframe stillness determination circuit 40 (FIG. 2) in the first embodiment. And three differential operation circuits 61c output three types of frame difference signals, and three absolute value circuits 62a, 62b and 62b provide three types of absolute value signals. This is output and input to the determination circuit 43 or the determination circuit 63. As a result, the absolute value of the frame difference signal used for the interframe stillness determination has increased, so that a more accurate stillness determination can be performed, and accordingly, the luminance signal and the color signal can be accurately separated.

Embodiment 7 FIG.
FIG. 18 is a block diagram showing a high-frequency luminance component extraction circuit 14B used in the motion detection circuit of the luminance signal color signal separation circuit according to the seventh embodiment. The high-frequency luminance component extraction circuit 14B shown in the figure is generally the same as the high-frequency luminance component extraction circuit 14A shown in FIG. 15, but an isolated point removal unit 47 is inserted between the absolute value conversion unit 62 and the determination circuit 63. It is different in point.
FIG. 19 is a block diagram showing in detail an example of the inter-frame stillness determination circuit 40B in the high frequency luminance component extraction circuit 14B of FIG.
The inter-frame stillness determination circuit 40B shown is generally the same as the inter-frame stillness determination circuit 40A shown in FIG. 16, but as described with reference to FIG. 18, the isolated point removal unit 47 between the absolute value conversion unit 62 and the determination circuit 63. Is different in that the isolated point removing unit 47 includes isolated point removing circuits 47a to 47c.
The isolated point removing circuits 47a to 47c remove isolated points in the outputs of the absolute value circuits 62a to 62c, respectively.
For example, the isolated point removal circuit 47a is a signal in which the signal of the previous and subsequent pixels in the horizontal direction is a small level even if the output signal of the absolute value circuit 62a (the signal of the target pixel) is a large level signal. In some cases, the output signal (signal of the target pixel) is set to a small level.

The relationship between the column of the input signal DZa and the column of the output signal KJa of the isolated point removal circuit 47a is the same as that described for the isolated point removal circuit 44 with reference to FIGS. However, the signals JG and SF and the threshold value JGt should be replaced with the signals DZa and KJa and the threshold value DZat, respectively.
The isolated point removal circuit 47b and the isolated point removal circuit 47c use the same threshold values DZbt and DZct as the threshold value DZat for the outputs DZb and DZc of the absolute value circuits 62b and 62c, respectively. I do.

  In the high frequency luminance component extraction circuit 14B of FIGS. 18 and 19, for example, only the isolated point is removed from the output of the determination circuit 43, compared with the high frequency luminance component extraction circuit 14A (FIG. 15) in the sixth embodiment. Instead, the isolated point is also removed from the output of the absolute value converting unit 62. When noise is mixed in the input signal, the noise component is erroneously detected as an inter-frame difference signal, making it difficult to determine that the original still signal is still. By disposing it before, it is possible to make a more accurate still determination without erroneously detecting a noise component as an inter-frame difference signal.

  The motion detection circuits of the third embodiment, the fifth embodiment, and the seventh embodiment are also modified in the same manner as described in the first embodiment, for example, in the same manner as described with reference to FIG. Can be added.

  In the above embodiment, selection means for selecting and outputting one of the output signal from the two-dimensional color signal extraction circuit 2 and the output signal from the three-dimensional color signal extraction circuit based on the output signal from the motion detection circuit 10. However, the output signal from the motion detection circuit is multi-bited, and based on the multi-bit motion detection signal, the output signal from the two-dimensional color signal extraction circuit and the output signal from the three-dimensional color signal extraction circuit It is also possible to have a mixing means that determines and outputs the mixing ratio. The selection means used in the above embodiment is a kind of mixing means, and it can be considered that the mixing ratio is set to 1: 0. Should be interpreted.

Embodiment 8 FIG.
In the above embodiment, one of the output signal (color signal) from the two-dimensional color signal extraction circuit and the output signal (color signal) from the three-dimensional color signal extraction circuit 7 is selected, and the selected color is selected. The luminance signal is extracted by subtracting the signal from the composite color television signal, but the output signal (color signal) from the two-dimensional color signal extraction circuit 3 and the output signal (color signal) from the three-dimensional color signal extraction circuit 7 ) Are subtracted from the composite color television signal to extract each luminance signal, and each of the color signal and the luminance signal is obtained as a result of two-dimensional processing based on the motion detection signal from the motion detection circuit 10. A configuration may be adopted in which a signal and a signal obtained as a result of three-dimensional processing are mixed and output. FIG. 20 shows a configuration (Embodiment 8) when the embodiment of FIG. 10 is modified based on this idea.

The luminance signal color signal separation circuit shown in FIG. 20 is generally the same as the luminance signal color signal separation circuit shown in FIG. 10 except that difference calculation circuits 6 a and 6 b are provided instead of the difference calculation circuit 6. Instead, mixing circuits 5a and 5b are provided, and the motion detection signal MF output from the motion detection circuit 10 is supplied to the mixing means 5y and 5c.
The difference calculation circuit 6a subtracts the color signal Ca output from the 2D filter 2 from the composite color television signal VS0 and outputs a luminance signal Ya. The difference calculation circuit 6b subtracts the color signal Cb output from the three-dimensional color signal extraction circuit 7 from the composite color television signal VS0, and outputs a luminance signal Yb.
The mixing means 5y mixes and outputs the luminance signal Ya or Yb based on the motion detection signal MF from the motion detection circuit 10. The mixing unit 5 c mixes and outputs the color signal Ca or Cb based on the motion detection signal MF from the motion detection circuit 10.

It is a block diagram which shows the motion detection circuit of Embodiment 1 of this invention. It is a block diagram which shows an example of the high region luminance signal detection circuit 14 used with the motion detection circuit of FIG. It is a block diagram which shows an example of the motion detection signal generation circuit 15 used with the motion detection circuit of FIG. 3 is a graph showing the relationship between the value of an input signal and the value of an output signal of each pixel when the determination circuit 43 in FIG. 2 outputs a quaternary signal. 3 is a graph showing the relationship between the value of an input signal and the value of an output signal of each pixel when the determination circuit 43 in FIG. 2 outputs a binary signal. (A) And (b) shows the relationship between the column of the input signal JG and the column of the output signal SF of the isolated point removal circuit 44 when the determination circuit 43 of FIG. 2 outputs a quaternary signal. FIG. (A) And (b) shows the relationship between the column of the input signal JG and the column of the output signal SF of the isolated point removal circuit 44 when the determination circuit 43 of FIG. 2 outputs a binary signal. FIG. (A) And (b) is a figure which shows the relationship between the column of the input signal of the horizontal expansion circuit 53, and the column of an output signal in case the output signal of the absolute value circuit 52 of FIG. 2 is a quaternary signal. . (A) And (b) is a figure which shows the relationship between the column of the input signal of the horizontal expansion circuit 53, and the column of an output signal in case the output signal of the absolute value circuit 52 of FIG. 2 is a binary signal. . It is a block diagram which shows the luminance signal color signal separation circuit of Embodiment 2 of this invention. It is a block diagram which shows the motion detection circuit of Embodiment 3 of this invention. FIG. 12 is a block diagram illustrating an example of a high-frequency luminance component extraction circuit 14 used in the motion detection circuit of FIG. 11. It is a block diagram which shows the luminance signal color signal separation circuit of Embodiment 4 of this invention. It is a block diagram which shows the motion detection circuit of Embodiment 5 of this invention. It is a figure which shows an example of 14 A of high frequency luminance component extraction circuits of FIG. FIG. 16 is a block diagram illustrating an example of an inter-frame stillness determination circuit 40A in the high-frequency luminance component extraction circuit 14A of FIG. It is a block diagram which shows the luminance signal color signal separation circuit of Embodiment 6 of this invention. FIG. 20 is a block diagram showing a high-frequency luminance component extraction circuit 14B used in the motion detection circuit of the luminance signal color signal separation circuit according to the seventh embodiment. FIG. 19 is a block diagram showing in detail an example of an inter-frame stillness determination circuit 40B in the high-frequency luminance component extraction circuit 14B of FIG. It is a block diagram which shows the luminance signal color signal separation circuit of Embodiment 8 of this invention.

Explanation of symbols

2, 2A 2D color extraction circuit (2D filter) 3, 3A 1 frame delay circuit, 4 difference calculation circuit, 5 selection means, 5a, 5b mixing means, 6, 6c, 6y difference calculation circuit, 7 3D color extraction Circuit, 10 motion detection circuit, 11 differential operation circuit, 12 low-pass filter (LPF), 13 band-pass filter (BPF), 14 high-frequency luminance component extraction circuit, 15 motion detection signal generation circuit, 31, 32 1 frame delay Circuit, 40, 40A, 40B interframe stillness determination circuit, 41 difference calculation circuit, 42 absolute value circuit, 43 determination circuit, 44 isolated point removal circuit, 46 difference absolute value calculation circuit, 47 isolated point removal unit, 47a, 47b, 47c isolated point removal circuit, 50 color subcarrier frequency component detection circuit, 51 horizontal / vertical band pass filter, 52 absolute value circuit, 53 horizontal expansion Circuit 55 combining circuit, 61 difference calculation unit, 61a, 61b, 61c difference calculation circuit, 62 an absolute value unit, 62a, 62b, 62c absolute value circuit, 63 determination circuit, 64 a maximum value circuit, 65 a comparison circuit.

Claims (11)

A composite color television signal and a delay signal obtained by delaying the composite color television signal by one frame period or two frame periods are input, a difference between the composite color television signal and the delay signal is calculated, and a difference representing the difference is calculated. A differential operation circuit for outputting a signal;
A low-pass filter that extracts a low-frequency component below the color subcarrier frequency from the difference signal output from the difference calculation circuit;
A band-pass filter that extracts a frequency component near the color subcarrier frequency from the difference signal output from the difference calculation circuit;
A high-frequency luminance component extraction circuit that receives the composite color television signal and the delayed signal as input and extracts a high-frequency luminance component;
A motion detection signal generation circuit that outputs a motion detection signal by combining the output signal of the low-pass filter and the output signal of the band-pass filter;
The high-frequency luminance component extraction circuit is
A frame stillness determination circuit that receives the frame of the composite color television signal and the frame of the delayed signal as input, and detects stillness of the luminance signal between the frames,
A color subcarrier frequency detection circuit for detecting an oblique fringe component composed of a luminance signal near the color subcarrier frequency;
A synthesis circuit that synthesizes the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency detection circuit;
The output signal of the frame stillness determination circuit becomes a signal having a larger value as the degree of stillness between the composite color television signal and the delayed signal increases.
The output signal of the color subcarrier frequency component detection circuit becomes a signal having a larger value as the color subcarrier frequency component increases,
The synthesis circuit outputs a signal having a larger value of the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency component detection circuit as a signal representing the high-frequency luminance component,
The motion detection signal generation circuit includes:
When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit is less than or equal to a predetermined threshold value, the larger one of the output signal value of the low-pass filter and the output signal value of the band-pass filter A signal having the same value as is output as the motion detection signal,
When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit has a value larger than the threshold value, the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter A motion detection circuit characterized in that a signal having a value obtained by multiplying the same value as the larger value by a coefficient smaller than 1 or a signal having a value of 0 is output as the motion detection signal.   A composite color television signal and a delay signal obtained by delaying the composite color television signal by one frame period or two frame periods are input, a difference between the composite color television signal and the delay signal is calculated, and a difference representing the difference is calculated. A differential operation circuit for outputting a signal;
  A low-pass filter that extracts a low-frequency component below the color subcarrier frequency from the difference signal output from the difference calculation circuit;
  A band-pass filter that extracts a frequency component near the color subcarrier frequency from the difference signal output from the difference calculation circuit;
  A high-frequency luminance component extraction circuit that receives the composite color television signal and the delayed signal as input and extracts a high-frequency luminance component;
  A motion detection signal generation circuit that outputs a motion detection signal by combining the output signal of the low-pass filter and the output signal of the band-pass filter;
  The high-frequency luminance component extraction circuit is
  A frame stillness determination circuit that receives the frame of the composite color television signal and the frame of the delayed signal as input, and detects stillness of the luminance signal between the frames,
  A color subcarrier frequency detection circuit for detecting an oblique fringe component composed of a luminance signal near the color subcarrier frequency;
  A synthesis circuit that synthesizes the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency detection circuit;
  The output signal of the frame stillness determination circuit becomes a signal having a larger value as the degree of stillness between the composite color television signal and the delayed signal increases.
  The output signal of the color subcarrier frequency component detection circuit becomes a signal having a larger value as the color subcarrier frequency component increases,
  The synthesis circuit outputs a signal having a value obtained by adding the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency component detection circuit as a signal representing the high frequency luminance component,
  The motion detection signal generation circuit includes:
  When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit is less than or equal to a predetermined threshold value, the larger one of the output signal value of the low-pass filter and the output signal value of the band-pass filter A signal having the same value as is output as the motion detection signal,
  When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit has a value larger than the threshold value, the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter A signal having a value obtained by multiplying the same value as the larger value by a coefficient smaller than 1 or a signal having a value of 0 is output as the motion detection signal.
  A motion detection circuit characterized by that.   A composite color television signal and a delay signal obtained by delaying the composite color television signal by one frame period or two frame periods are input, a difference between the composite color television signal and the delay signal is calculated, and a difference representing the difference is calculated. A differential operation circuit for outputting a signal;
  A low-pass filter that extracts a low-frequency component below the color subcarrier frequency from the difference signal output from the difference calculation circuit;
  A band-pass filter that extracts a frequency component near the color subcarrier frequency from the difference signal output from the difference calculation circuit;
  A high-frequency luminance component extraction circuit that receives the composite color television signal and the delayed signal as input and extracts a high-frequency luminance component;
  A motion detection signal generation circuit that outputs a motion detection signal by combining the output signal of the low-pass filter and the output signal of the band-pass filter;
  The high-frequency luminance component extraction circuit is
  A frame stillness determination circuit that receives the frame of the composite color television signal and the frame of the delayed signal as input, and detects stillness of the luminance signal between the frames,
  A color subcarrier frequency detection circuit for detecting an oblique fringe component composed of a luminance signal near the color subcarrier frequency;
  A synthesis circuit that synthesizes the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency detection circuit;
  The output signal of the frame stillness determination circuit becomes a signal having a larger value as the degree of stillness between the composite color television signal and the delayed signal increases.
  The output signal of the color subcarrier frequency component detection circuit becomes a signal having a larger value as the color subcarrier frequency component increases,
  The synthesis circuit outputs a signal having a larger value of the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency component detection circuit as a signal representing the high-frequency luminance component,
  The motion detection signal generation circuit includes:
  When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit is less than or equal to a predetermined threshold, a value obtained by adding the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter is Output the signal as a motion detection signal,
  When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit has a value larger than the threshold value, the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter are added. A signal having a value obtained by multiplying the value by a coefficient smaller than 1 or a signal having a value of 0 is output as the motion detection signal.
  A motion detection circuit characterized by that.   A composite color television signal and a delay signal obtained by delaying the composite color television signal by one frame period or two frame periods are input, a difference between the composite color television signal and the delay signal is calculated, and a difference representing the difference is calculated. A differential operation circuit for outputting a signal;
  A low-pass filter that extracts a low-frequency component below the color subcarrier frequency from the difference signal output from the difference calculation circuit;
  A band-pass filter that extracts a frequency component near the color subcarrier frequency from the difference signal output from the difference calculation circuit;
  A high-frequency luminance component extraction circuit that receives the composite color television signal and the delayed signal as input and extracts a high-frequency luminance component;
  A motion detection signal generation circuit that outputs a motion detection signal by combining the output signal of the low-pass filter and the output signal of the band-pass filter;
  The high-frequency luminance component extraction circuit is
  A frame stillness determination circuit that receives the frame of the composite color television signal and the frame of the delayed signal as input, and detects stillness of the luminance signal between the frames,
  A color subcarrier frequency detection circuit for detecting an oblique fringe component composed of a luminance signal near the color subcarrier frequency;
  A synthesis circuit that synthesizes the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency detection circuit;
  The output signal of the frame stillness determination circuit becomes a signal having a larger value as the degree of stillness between the composite color television signal and the delayed signal increases.
  The output signal of the color subcarrier frequency component detection circuit becomes a signal having a larger value as the color subcarrier frequency component increases,
  The synthesis circuit outputs a signal having a value obtained by adding the output signal of the frame stillness determination circuit and the output signal of the color subcarrier frequency component detection circuit as a signal representing the high frequency luminance component,
  The motion detection signal generation circuit includes:
  When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit is less than or equal to a predetermined threshold, a value obtained by adding the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter is Output the signal as a motion detection signal,
  When the high-frequency luminance component extracted by the high-frequency luminance component extraction circuit has a value larger than the threshold value, the value of the output signal of the low-pass filter and the value of the output signal of the band-pass filter are added. A signal having a value obtained by multiplying the value by a coefficient smaller than 1 or a signal having a value of 0 is output as the motion detection signal.
  A motion detection circuit characterized by that. The frame stationary determination circuit is
For each pixel, a difference absolute value calculating means for obtaining an absolute value of a difference value between the composite color television signal and the delayed signal;
For each pixel, determination means for outputting a signal that becomes a relatively small value when the absolute value of the difference value obtained by the difference absolute value calculation means is relatively large;
Motion detection circuit according to any one of claims 1 to 4, characterized in that it comprises an isolated point removing means for removing an isolated point in the output of said determination means. The color subcarrier frequency component detection circuit is
A horizontal / vertical band-pass filter that extracts color subcarrier frequency components by filtering the composite color television signal in the horizontal and vertical directions;
Absolute value obtaining means for obtaining an absolute value of the output of the horizontal / vertical band pass filter;
Motion detection circuit according to any one of claims 1 to 4, characterized in that it comprises a horizontal expansion means for expanding the output of said absolute value means in the horizontal direction. Ri signal der which the delayed signal is delayed two frame periods,
The inter-frame still decision circuit, as the delay signal, and also inputs the 2-frame period delayed signal to the addition of one frame period delayed signal,
The upper Symbol difference absolute value calculation means,
A first difference absolute value calculation circuit for obtaining an absolute value of a difference value between the composite color television signal and the signal delayed by one frame period;
A second difference absolute value calculation circuit for obtaining an absolute value of a difference value between the composite color television signal and the signal delayed by two frame periods;
A third difference absolute value calculation circuit for obtaining an absolute value of a difference value between the signal delayed by one frame period and the signal delayed by two frame periods;
The determination means is
A maximum value circuit for obtaining a maximum value among outputs of the first difference absolute value calculation circuit, output of the second difference absolute value calculation circuit, and output of the third difference absolute value calculation circuit;
For each pixel, Ri Do a relatively small value when the output of said maximum value circuit is greater than a predetermined threshold value, a relatively small value and ing signal when the output of said maximum value circuit is smaller than the predetermined threshold The motion detection circuit according to claim 5 , further comprising a comparison circuit for outputting. Ri signal der which the delayed signal is delayed two frame periods,
The inter-frame still decision circuit, as the delay signal, and also inputs the 2-frame period delayed signal to the addition of one frame period delayed signal,
The upper Symbol difference absolute value calculation means,
A first difference absolute value calculation circuit for obtaining an absolute value of a difference value between the composite color television signal and the signal delayed by one frame period;
A second difference absolute value calculation circuit for obtaining an absolute value of a difference value between the composite color television signal and the signal delayed by two frame periods;
A third difference absolute value calculation circuit for obtaining an absolute value of a difference value between the signal delayed by one frame period and the signal delayed by two frame periods;
A first isolated point removal circuit for removing isolated points in the output of the first differential absolute value calculation circuit;
A second isolated point removal circuit for removing isolated points in the output of the second absolute difference calculation circuit;
A third isolated point removal circuit for removing isolated points in the output of the third difference absolute value calculation circuit;
The determination means is
A maximum value circuit for obtaining a maximum value among the output of the first isolated point removal circuit, the output of the second isolated point removal circuit, and the output of the third isolated point removal circuit;
For each pixel, Ri Do a relatively small value when the output of said maximum value circuit is greater than a predetermined threshold value, a relatively small value and ing signal when the output of said maximum value circuit is smaller than the predetermined threshold The motion detection circuit according to claim 5 , further comprising a comparison circuit for outputting. The determination means has a relatively large value when the output signal of the difference absolute value calculation means is smaller than a predetermined threshold, and is relatively small if the output signal of the difference absolute value calculation means is equal to or greater than the threshold. The motion detection circuit according to claim 5 , wherein a value signal is output. The determination means outputs a signal having three or more values,
When the output of the difference absolute value calculation means is equal to or greater than a predetermined threshold, the output is “0”. When the output of the difference absolute value calculation means is smaller than the threshold, the output is the difference absolute value calculation. The motion detection circuit according to claim 9 , wherein the motion detection circuit has a magnitude corresponding to a difference between the output of the means and the threshold value. A motion detection circuit according to any one of claims 1 to 10 ,
A delay circuit for inputting the composite color television signal and delaying and outputting the composite color television signal by the predetermined frame period;
A two-dimensional color signal extraction circuit for extracting a first color signal from signals in the field;
A three-dimensional color signal extraction circuit that extracts a second color signal using frame correlation;
Based on the motion detection signal output from the motion detection circuit, the third color is obtained by mixing the color signal output from the two-dimensional color signal extraction circuit and the color signal output from the three-dimensional color signal extraction circuit. Mixing means for outputting a signal;
A luminance signal extraction circuit for extracting a luminance signal based on the composite color television signal and the first and second color signals or the third color signal;
The luminance signal color signal separation circuit, wherein the motion detection circuit receives the output of the delay circuit as a delayed signal delayed by the predetermined frame period.

Images