JP3231309B2 - Motion information signal detection circuit - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a signal processing circuit for a television signal,
In particular, the present invention relates to a motion information signal detection circuit suitable for generating a signal for controlling a motion adaptive signal processing circuit.

2. Description of the Related Art A motion-adaptive signal processing circuit that processes a television signal according to the motion of an image is very effective for obtaining a high-quality image. For example, in a receiver for an NTSC composite color television signal, a luminance signal and a chrominance signal are separated from a still image signal by using the correlation of signals between a plurality of frames, and a plurality of The luminance signal and the chrominance signal are separated using the correlation between the signals between lines. As a result, it is possible to suppress the occurrence of dot disturbance, cross color, and the like. As for the scanning line interpolation, an interpolation signal is generated using a signal of an adjacent field for a still image signal, and an interpolation signal is generated using a signal of one field for a moving image signal. As a result, the occurrence of line flicker can be prevented, and the vertical resolution can be improved.

This motion adaptive signal processing circuit is effective when the motion of an image is accurately detected. However, if the detection of the motion of the image is not accurate, for example, a moving image processing is performed on a still image or a still image processing is performed on a moving image, which causes deterioration in image quality.

Japanese Patent Application Laid-Open No. 63-90987 is a conventional example of a motion detection circuit having few errors in motion detection even for a fast-moving image. FIG. 13 shows a circuit block diagram of the conventional example. In FIG. 13, 2 is an input terminal, 3 is a one-frame memory, 4 and 12 are subtraction circuits, 5 is a low-pass filter circuit (hereinafter referred to as LPF), 6 and 13 are absolute value circuits, and 7 and 14 are nonlinear. Conversion circuit,
8 is a band-pass filter circuit (hereinafter referred to as BPF), 9 is an automatic color saturation control amplifier circuit (hereinafter referred to as ACC amplifier circuit), 10 is a demodulation circuit, 11 is a two-frame memory, and 15 is a synthesis circuit. , 17 are spatiotemporal processing circuits.

The input terminal 2 receives, for example, a digitized NTSC composite color television signal (hereinafter referred to as a color television signal). This is delayed by one frame period in the one-frame memory 3, and a subtraction circuit 4 creates a one-frame difference signal. Here, when the difference signal between one frame is zero, it is determined to be a still image, and when it is not zero, it is determined to be a moving image, so that the motion of the image can be detected. However,
In a color television signal, the luminance signal component has the same phase and the chrominance signal component has the opposite phase in one frame.
The one-frame difference signal contains a color signal component in addition to the motion component. Therefore, the color signal component is removed by the LPF 5 to obtain a luminance component motion detection signal. Further, the absolute value circuit 6 removes the positive and negative polarities of the difference signal. Absolute value circuit 6
Is supplied to the nonlinear conversion circuit 7 to compress the bits. Here, the motion detection signal of the luminance component input to the non-linear conversion circuit 7 is an 8-bit signal if the input color television signal is quantized by, for example, 8 bits. The nonlinear conversion circuit 7 compresses the 8-bit signal into, for example, a 4-bit signal to reduce the number of bits. Even in this case, switching of the motion adaptive signal processing circuit can be performed in 16 steps, and sufficiently smooth switching can be performed.

On the other hand, in the conventional example, the movement of the color component of the image is detected as follows. The color television signal input from the input terminal 2 is band-limited by the BPF 8 to extract a signal in a color signal band. The ACC amplifying circuit 9 operates so as to keep the level of the burst signal included in the output signal of the BPF 8 constant, and outputs a color signal having a substantially constant amplitude in which the variation of the color signal level due to the frequency characteristic of the transmission path is corrected. Output. Thereafter, the demodulation circuit 10 performs color demodulation of the color signal, and obtains a signal obtained by multiplexing two color difference signals (RY) and (BY) in the output terminal of the demodulation circuit 10 in a point-sequential manner. Although the phase of the chrominance subcarrier is inverted during one frame, the demodulation circuit 10 is configured to cancel the inversion during one frame. The signal of the color signal band input to the demodulation circuit 10 includes a high frequency component of a luminance signal in addition to the color signal. Therefore, the output terminal of the demodulation circuit 10 outputs a signal in which the high frequency component of the luminance signal is inverted for one frame. The output signal of the demodulation circuit 10 is input to the two-frame memory 11 and is delayed by two frame periods.
Then, a subtraction circuit 12 creates a difference signal between two frames. 2
A color signal between two signals separated by a frame period,
Both the high-frequency components of the luminance signal have the same phase. Therefore, when the difference signal between two frames is zero, it is a still image,
If not zero, it is a movie. That is, the difference signal between the two frames becomes the motion detection signal of the color component. After that, the absolute value circuit 13 removes the positive and negative polarities of the difference signal, and the non-linear conversion circuit 14 compresses the absolute value of the motion detection signal of the color component in the same manner as the motion detection signal of the luminance component.

Then, the motion detection signal of the luminance component and the motion detection signal of the color component which have been bit-compressed are supplied to the synthesizing circuit 15 to synthesize both signals. The output signal of the synthesizing circuit 15 is input to the spatiotemporal processing circuit 17, and a motion that cannot be detected by the difference between frames, for example,
The detected motion signal is stretched in the time direction and the space direction so that there is a motion even for a fast-moving image or a fine image. As a result, a motion information signal that prevents the detection of motion from leaking out is obtained. Then, the motion information signal from the spatiotemporal processing circuit 17 is output from the output terminal 20 and used as a control signal for the motion adaptive signal processing circuit.

[Problems to be solved by the invention]

In the above conventional example, as a result of expanding the motion signal in the spatio-temporal processing circuit 17, if the region determined to have motion reaches the edge portion of the image, the edge portion is subjected to moving image processing,
There has been a problem that dot disturbance and image flickering occur to deteriorate image quality.

An object of the present invention is to provide a motion information signal detection circuit capable of suppressing erroneous detection of motion at an edge portion caused by spatiotemporal processing and performing more accurate detection.

[Means for solving the problem]

In order to achieve the above object, a motion information signal detection circuit according to the present invention includes a motion detection circuit that detects image motion from a digitized television signal, and a motion detection signal output from the motion detection circuit. And a spatio-temporal processing circuit for stretching in the spatial direction, an edge detection circuit for detecting an edge portion of an image from the television signal, and an output signal from the spatio-temporal processing circuit as an input signal thereof, the edge detection circuit And an adaptive conversion circuit for level-converting and outputting the input signal in accordance with the level of the edge detection signal output from the input signal. The conversion characteristic is such that the level of the output signal with respect to a certain level is reduced.

[Action]

The motion detection circuit detects a motion of an image using a difference signal between frames. The spatio-temporal processing circuit stretches the motion in the temporal and spatial directions. The edge detection circuit detects an edge portion of an image using correlation with peripheral pixels. The adaptive conversion circuit reduces the level of the motion information at the edge portion. As a result, erroneous detection of motion at the edge portion can be suppressed, and a motion information detection circuit with higher detection accuracy can be realized.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to FIG. In FIG. 1, 1 is a motion detection circuit, 2 is an input terminal, 3 is a one-frame memory, 4 and 12 are subtraction circuits, 5 is an LPF, 6, 1
3 is an absolute value circuit, 7 and 14 are nonlinear conversion circuits, 8 is a BPF, 9
Is an ACC amplifier circuit, 10 is a demodulation circuit, 11 is a two-frame memory, 15 is a synthesis circuit, 16 is a noise removal circuit, 17 is a spatio-temporal processing circuit, 18 is an adaptive conversion circuit, and 19 is an edge detection circuit.

For example, a digitized color television signal is input to the input terminal 2, and a one-frame memory 3 and a subtraction circuit 4 obtain a difference signal between one frame. The color signal component included in the one-frame difference signal is removed by the LPF 5 to create a motion detection signal of a luminance component. Thereafter, the absolute value circuit 6 removes the positive and negative polarities of the difference signal, and the nonlinear conversion circuit 7 performs bit compression.

On the other hand, the color television signal input from the input terminal 2 is band-limited by the BPF8 to extract the signal of the color signal band,
The ACC amplification circuit 9 corrects the fluctuation of the burst signal level, and the demodulation circuit 10 performs color demodulation. The demodulated color signal is 2
The frame memory 11 and the subtraction circuit 12 create a difference signal between two frames. That is, a motion detection signal of the color component is obtained.
Thereafter, the absolute value circuit 13 removes the positive and negative polarities of the difference signal, and the nonlinear conversion circuit 14 performs bit compression.

Then, the combining circuit 15 combines the motion detection signal of the luminance component and the motion detection signal of the color component that have been bit-compressed. And
The output signal of the synthesizing circuit 15 is input to the noise removing circuit 16 to remove noise in the motion signal. In the noise removal circuit 16,
Noise is removed by utilizing the fact that there is no correlation between the motion detection signal from the noise pixel and the motion detection signal from the peripheral pixels, thereby preventing erroneous motion detection due to noise. The output signal of the noise elimination circuit 16 is input to the spatio-temporal processing circuit 17 and the noise-removed motion signal is stretched in the time direction and the spatial direction, so that the motion can be performed without error even for a fast-moving image or an image with a fine pattern. Is determined.

Further, the color television signal input from the input terminal 2 is further supplied to the edge detection circuit 19. The edge detection circuit 19 detects an edge portion of the image and outputs an edge detection signal l. Then, the output signal of the spatiotemporal processing circuit 17 and the edge detection signal 1 are input to the adaptive conversion circuit 18. The adaptive conversion circuit 18 performs a conversion process according to the level of the edge detection signal 1 on the motion information signal subjected to the spatio-temporal processing, and reduces unnecessary motion information reaching the edge portion by the spatio-temporal processing. As a result, it is possible to suppress erroneous motion detection at the edge portion. Then, the output signal of the adaptive conversion circuit 18 is output from the output terminal 20 as a motion information signal, and is used as a control signal of the motion adaptive signal processing circuit.

Next, the detailed configuration of the edge detection circuit will be described with reference to FIG.
An example of the operation will be described. FIG. 2 is a block diagram showing the configuration of the edge detection circuit 19. In FIG. 2, 19 is an edge detection circuit, 2 is an input terminal, 21 is a 1H (1H is one horizontal scanning cycle of a television signal) memory, 22 is a subtraction circuit, and 23 is an LP.
F and 24 are absolute value circuits, 25 is a bit compression circuit, and 26 is an output terminal. The edge detection circuit 19 shown in FIG. 2 utilizes the correlation between vertically adjacent pixels in the same field,
Detect vertical edge portions of the image. First, the color television signal input from the input terminal 2 is supplied to the 1H memory 21 and is delayed by 1H period. Then, the input color television signal and the color television signal delayed by 1H period are input to the subtraction circuit 22, and the difference between the two signals is obtained. If there is a vertical edge in the same field,
A significant signal component is generated in the 1H difference signal at the pixel.
In addition, if it is not an edge portion, the 1H difference signal becomes zero, so that an edge portion of an image can be detected by creating a 1H difference signal. However, in the case of a color television signal, since the color signal components have opposite phases between lines, a significant signal component also occurs in the 1H difference signal in a portion other than the edge. Therefore, the LPF 23 removes the color signal component included in the 1H difference signal. Thereafter, the absolute value circuit 24 removes the positive and negative polarities of the difference signal. The bit compression circuit 25 compresses the edge detection signal created by the absolute value circuit 24 from, for example, 8 bits to 2 bits as a control signal of the adaptive conversion circuit 18.
Then, the output signal of the bit compression circuit 25 is output from the output terminal 26 as an edge detection signal l.

The edge detection signal l generated by the edge detection circuit 19
Can be used as a control signal for the nonlinear conversion circuits 7 and 14 in the motion detection circuit 1 in addition to the control signal for the adaptive conversion circuit 18. The detected motion signal is converted into a nonlinear conversion circuit 7,
At the time of bit compression at 14, for example, when the edge level 1 is high, the bit compression characteristic is set to reduce the motion signal level, and when the edge level 1 is low, the bit compression characteristic is set to increase the motion signal level. Set. As a result, it is possible to suppress erroneous detection of motion at an edge portion occurring before the spatio-temporal processing.

Next, using FIG. 3, FIG. 4, and FIG.
An example of the detailed configuration and operation of the 18 will be described. FIG. 3, FIG.
FIG. 5 is a block diagram showing a configuration of the adaptive conversion circuit 18, and FIG. 5 is a diagram showing an example of conversion characteristics of the adaptive conversion circuit. Third
In FIG. 4 and FIG. 4, 18 is an adaptive conversion circuit, 2 and 27 are input terminals, 28, 29, 30, and 31 are conversion circuits having different conversion characteristics, and 33, 34, 35, and 36 are constant multiplications having different constants. Circuit, 32 is a selection circuit, and 19 is an edge detection circuit. Here, a configuration will be described in which the conversion characteristics of the adaptive conversion circuit 18 are switched, for example, in four ways. In FIG. 5, the horizontal axis represents the motion information level input to the adaptive conversion circuit 18,
The vertical axis indicates the output motion information level, and the conversion characteristic is such that the output motion information can be expressed by a constant multiple of the input motion information. That is, the conversion characteristic a is a characteristic in which the output motion information level is α times the input motion information level, Characteristic b is β times, characteristic c is γ times,
The characteristic d is a characteristic multiplied by δ. First, the motion information signal input from the input terminal 27 is input to the conversion circuits 28, 29, 30, and 31, respectively. The input motion information is converted by the conversion circuit 28 into a conversion characteristic a shown in FIG.
The conversion circuit 30 converts the data with the characteristic c, and the conversion circuit 31 converts the data with the characteristic d, and outputs the converted data. The conversion circuits 28, 29, 30, 31 specifically include constants α, β, as shown in FIG. 4, for example.
Constant multiplication circuit in which γ and δ are set as α>β>γ> δ
By using 33, 34, 35 and 36, the conversion characteristics shown in FIG. 5 can be realized. After that, the output signals of the conversion circuits 28, 29, 30, 31 are input to the selection circuit 32. The selection circuit 32 selects and outputs any one of the four input signals according to the level of the edge detection signal 1 detected by the edge detection circuit 19. For example, assume that the level of the edge detection signal 1 is four levels (0, 1, 2, 3). When the edge detection signal 1 is at level 0, the output signal of the conversion circuit 28 is selected. When the edge detection signal 1 is at level 1, the output of the conversion circuit 29 is selected. When it is at level 2, the output of the conversion circuit 30 is selected. , Level 3, conversion circuit
The selection circuit 32 is configured to select the output of 31. As a result, it is possible to realize an adaptive conversion circuit 18 that switches the conversion characteristics according to the level of the edge detection signal l. As the edge level l increases, the motion information is output at a smaller level. False detection can be suppressed.

Here, conversion characteristics other than those shown in FIG.
Depending on the configuration of 28, 29, 30, 31 it can be set arbitrarily. For example, as shown in FIG. 6, the output motion information level is smaller than the input motion information level by a certain amount.
That is, the conversion characteristic a is a characteristic in which the output motion information level is -α from the input motion information level, the characteristic b is -β, and the characteristic c is
Is -γ, and the characteristic d is -δ, the conversion circuits 28, 29, 30, 31 in FIG.
This can be realized by using a constant subtraction circuit set as β <γ <δ. Further, the switching of the characteristics is not limited to four stages, and can be arbitrarily set according to the number of conversion circuits.

As described above, according to the present embodiment, there is an effect that a more accurate motion information signal can be detected by suppressing erroneous detection of motion at an edge portion caused by spatiotemporal processing.

Next, another embodiment of the adaptive conversion circuit 18 according to the present invention will be described with reference to FIG. This embodiment is a small-scale adaptive conversion circuit composed of a coefficient generation circuit and a multiplication circuit.
It is an example of 18. FIG. 7 is a block diagram of the adaptive conversion circuit 18 described in this embodiment. 7, 18 is an adaptive conversion circuit, 27 is an input terminal, 37 is a multiplication circuit, 38 is a coefficient generation circuit, 20 is an output terminal, and 19 is an edge detection circuit.

The conversion characteristics of the adaptive conversion circuit 18 in this embodiment are the characteristics shown in FIG. 5 shown in the previous embodiment. An edge detection signal 1 detected by the edge conversion circuit 18 is supplied to a coefficient generation circuit 38,
A coefficient corresponding to the edge level 1 is created. Then, the multiplication circuit 37 multiplies the input motion information signal by the coefficient created by the coefficient generation circuit 38. When the level of the edge detection signal 1 is, for example, four levels (0, 1, 2, 3), the coefficient generating circuit 38 indicates that the coefficient α is at the edge level 0, β at the level 1, and γ at the level 2. In the case of level 3, the output of δ can be used to obtain the same motion information signal from the output terminal of the multiplication circuit 37 as that of the adaptive conversion circuit of FIG. Also, the conversion characteristics shown in FIG. 6 can be similarly realized by applying a subtraction circuit instead of the multiplication circuit 37.

As described above, according to the present embodiment, similarly to the previous embodiment, it is possible to detect a high-precision motion information signal that suppresses erroneous detection of motion occurring at an edge portion. Can be realized on a scale.

Next, another embodiment of the adaptive conversion circuit 18 according to the present invention will be described with reference to FIG. The present embodiment is an example of the adaptive conversion circuit 18 that realizes different conversion characteristics by bit shift. FIG. 8 is a block diagram of the adaptive conversion circuit 18 described in this embodiment. In FIG. 8, 18 is an adaptive conversion circuit, 27 is an input terminal, 32 is a selection circuit, 20 is an output terminal, and 19 is an edge detection circuit. In this embodiment, for example, the output motion information signal is one time (not converted) the input motion information signal,
A configuration in the case of switching between three-stage characteristics of 1/2 times and 1/4 times will be described. Now, if the input motion information signal is, for example, 4
It is assumed that a bit signal (x3, x2, x1, x0, x3 is the most significant bit, x2 is the second most significant bit, x1 is the third most significant bit, and x0 is the least significant bit). The selection circuit 32 has an input terminal a
(A3, a2, a1, a0, a3 are the most significant bits, a2 is the second most significant bit, a1 is the third most significant bit, and a0 is the least significant bit),
Input terminal b (b3, b2, b1, b0, b3 are the most significant bits, b2 is the second most significant bit, b1 is the third most significant bit, b0 is the least significant bit), and input terminal c (c3, c2, c1 , c0, c3 have the most significant bit, c2 is the second most significant bit, c1 is the third most significant bit, and c0 is the least significant bit. And output terminal y (y
3, y2, y1, y0, y3 are output from the most significant bit, y2 is the second most significant bit, y1 is the third most significant bit, and y0 is the least significant bit. Here, the conversion of 1/2 times and 1/4 times is performed by a bit shift of the input motion information signal. First, the input motion information signal is directly input to the input terminal a (x3 for a3 and x3 for a2,
x2, a1 x1, a0 x0). The input motion information signal is input to the input terminal b by shifting the input motion information signal right by one bit (b3 is fixed at the low level, x2 for b2, x2 for b1, and x1 for b0). The input motion information signal is shifted to the right by 2 bits and input to the input terminal c (b3, b
2 is low level setting, x1 for b1, x2 for b0). For example, when the input motion information level is 8 (1000), the input terminal a of the selection circuit 32 is 8 (1000), the input terminal b is 4 (0100),
2 (0010) is input to the input terminal c. Therefore, by adopting this configuration, a motion information signal of 1 times is input to the input terminal a, 1/2 times the input terminal b, and 1/4 times the input of the motion information signal to the input terminal c. Then, in the selection circuit 32, depending on the level of the edge detection signal l, the input terminals a,
One of the motion information signals b and c is selected. For example, when the level of the edge detection signal 1 is three levels (0, 1, 2), when the edge level is 0, the signal of the input terminal a (1 time)
Is selected, when the edge level is 1, the signal (1/2 times) of the input terminal b is selected, and when the edge level is 2, the signal (1/4 times) of the input terminal c is selected, and the output terminal y is selected. Output from Thus, similarly to the previous embodiment, it is possible to reduce the motion information at the edge portion and suppress erroneous motion detection.

As described above, according to the present embodiment, similarly to the previous embodiment, it is possible to suppress erroneous detection of a motion occurring in an edge portion and detect a highly accurate motion information signal. The adaptive conversion circuit 18 is connected to the selection circuit 32.
With this configuration, the circuit scale can be made very small.

Next, another embodiment of the edge detection circuit 19 according to the present invention will be described with reference to FIG. This embodiment is an example of an edge detection circuit 19 that detects a vertical edge portion and a horizontal edge portion of an image to generate an edge detection signal l. FIG. 9 is a block diagram of the edge detection circuit 19 described in this embodiment. In FIG. 9, 39 is a BPF, 40 is an absolute value circuit, 4
1 is a bit compression circuit, 42 is a synthesizing circuit, and others are the same as those in FIG. The vertical edge signal of the image in the present embodiment is converted into a 1H difference signal in the same manner as the edge detection circuit 19 in FIG.
LPF processing is performed, and detection is performed via an absolute value circuit 24 and a bit compression circuit 25. On the other hand, the horizontal edge portion of the image is detected by extracting a signal in a frequency band (for example, 1.8 ± 0.5 MHz) corresponding to the horizontal edge portion from the input color television signal. First, the color television signal input from the input terminal 2 is input to the BPF 39, and the filter processing is performed by the BPF 39 to generate a horizontal edge signal. Thereafter, similarly to the vertical edge detection, the absolute value circuit 40 removes the positive and negative polarities, and the bit compression circuit 41 performs bit compression. Combination circuit 42 for bit-compressed vertical and horizontal edge signals
And outputs it as an edge detection signal 1 from an output terminal 26. The edge detection signal 1 detected by the edge detection circuit 19 in the present embodiment includes both vertical and horizontal edge components of the image. Therefore, in the adaptive conversion circuit 18 controlled by the edge detection signal 1, erroneous detection of the movement of both the vertical edge and the horizontal edge can be suppressed.

As described above, according to the present embodiment, the edge detection circuit detects not only the vertical edge but also the horizontal edge, and synthesizes them to generate the edge detection signal l. Therefore, all the edge portions of the image can be detected. . Thereby, the adaptive conversion circuit 18
In, erroneous detection of motion of all edge portions of an image can be suppressed.

Next, another embodiment of the motion detection circuit 1 according to the present invention will be described with reference to FIG. The present embodiment is an example of a motion detection circuit 1 for detecting a motion signal of a color signal component using one frame memory and two 1H memories. FIG. 10 is a block diagram of the motion detection circuit 1 described in this embodiment. No.
10, 43 is a one-frame memory, 44 and 46 are 1H memories, 45 and 47 are subtraction circuits, 48 and 49 are absolute value circuits, 50 is an output terminal, and others are the same as those in FIG. The detection of the motion signal of the luminance signal component in the present embodiment is performed through the absolute value circuit 6 and the non-linear conversion circuit 7, by performing LPF processing on the difference signal between one frame as in the embodiment of FIG. On the other hand, the motion signal of the color component is performed as follows. First, the color television signal input from the input terminal 2 is supplied to the BPF 8, a signal in the color signal band is extracted, and the ACC amplifier circuit 9 corrects the level fluctuation of the burst signal. In the output signal of the ACC amplifier circuit 9, the high frequency component of the luminance signal has the same phase and the chrominance signal component has the opposite phase between one line. So, with 1H memory 44
Subtraction circuit for 1H delayed signal and 1H memory 44 input signal
By subtracting at 45, only the color signal component can be extracted. The output signal of the ACC amplifier circuit 9 is stored in a
To delay one frame period. From the signal delayed by one frame period, only the color signal component is extracted using the 1H memory 46 and the subtraction circuit 47 in the same manner as the processing of the input signal of the one frame memory 43. Here, since the two color signals output from the subtraction circuits 45 and 47 separated by one frame period have inverted phases, it is not possible to detect a motion from a simple difference between the two signals. Then, after the absolute values of both signals are obtained by the absolute value circuits 48 and 49, the motion of the color signal component is obtained by the subtraction circuit 12. Then, similarly to the embodiment of FIG. 1, the absolute value circuit 13 removes the positive and negative polarities, and the nonlinear conversion circuit 14 performs bit compression. Thereafter, the motion detection signal of the luminance component and the motion detection signal of the color component which have been bit-compressed are synthesized by the synthesizing circuit 15, subjected to noise elimination processing by the noise elimination circuit 16, and output from the output terminal 50 as a motion signal. As described above, according to the present embodiment, the motion of an image can be detected in the same manner as in the embodiment of FIG.
By using one 1H memory, the circuit scale can be reduced as compared with the embodiment of FIG.

Next, another embodiment of the present invention will be described with reference to FIG. The present embodiment is an example of a motion information signal detection circuit that performs a conversion process on a motion information signal subjected to spatio-temporal processing by two adaptive conversion circuits. FIG. 11 is a block diagram of a motion information signal detection circuit described in this embodiment. In FIG. 11, 1 is a motion detection circuit, 2 is an input terminal, 17 is a spatiotemporal processing circuit, 19 is an edge detection circuit, 51 and 52 are adaptive conversion circuits, and 52 and 53 are output terminals. First, a color television signal is input to the input terminal 2, and a motion information signal is obtained by the motion detection circuit 1 and the spatiotemporal processing circuit 17. After that, the motion information signal is supplied to the two adaptive conversion circuits 51 and 52, respectively, and the adaptive conversion circuits 51 and 52 are controlled by the edge detection signal 1 generated by the edge detection circuit to perform conversion processing. Then, output signals of the adaptive conversion circuits 51 and 52 are output from output terminals 53 and 54 as control signals of the motion adaptive signal processing circuit. Here, for example, the motion information signal from the output terminal 53 is used as a control signal of a motion adaptive luminance signal color signal separation circuit (hereinafter, referred to as an adaptive YC separation circuit), and the motion information signal from the output terminal 54 is It is used as a control signal for an adaptive scanning line interpolation circuit (hereinafter, referred to as an adaptive interpolation circuit). in this case,
The conversion characteristic of the adaptive conversion circuit 51 is set to an optimum characteristic as a control signal of the adaptive YC separation circuit, and the conversion characteristic of the adaptive conversion circuit 52 is set to an optimum characteristic as a control signal of the adaptive interpolation circuit. This makes it possible to more accurately suppress erroneous motion detection at an edge portion of an image.

Further, as shown in FIG. 12, a configuration in which only one of the motion information signal for controlling the adaptive YC separation circuit and the motion information signal for controlling the adaptive interpolation circuit is subjected to the edge-based adaptive conversion processing can be considered. In the case of this configuration, one of the motion adaptive signal processing circuits controls the emphasis on preventing malfunction due to missing motion detection, and the other motion adaptive signal processing circuit controls the motion detection at the edge portion. Thus, it is possible to detect a motion information signal that realizes control with an emphasis on malfunction prevention due to.

As described above, according to the present embodiment, by using two adaptive conversion circuits, it is possible to perform conversion processing using edges of two motion information signals for controlling the adaptive YC separation circuit and the adaptive interpolation circuit with optimal conversion characteristics. it can. As a result, it is possible to more accurately suppress image quality degradation due to erroneous detection of motion at an edge portion.

〔The invention's effect〕

According to the present invention, in the motion information signal detection circuit, the edge detection circuit and the adaptive conversion circuit can reduce unnecessary motion that is stretched by spatio-temporal processing and reaches the edge portion of the image, so that highly accurate motion can be achieved. An information signal can be detected. Thereby, in the motion adaptive signal processing circuit, there is an effect of suppressing image flickering and dot disturbance due to erroneous moving image processing at an edge portion.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is a block diagram showing a specific configuration of an edge detection circuit, FIG. 3 is a block diagram showing a specific configuration of an adaptive conversion circuit, and FIG. Is a block diagram showing another specific configuration of the adaptive conversion circuit, FIG. 5 is a characteristic diagram showing conversion characteristics of the adaptive conversion circuit, FIG. 6 is a characteristic diagram showing other conversion characteristics of the adaptive conversion circuit, and FIG. Is a block diagram showing another specific configuration of the adaptive conversion circuit, FIG. 8 is a block diagram showing another specific configuration of the adaptive conversion circuit, and FIG. 9 is a block diagram showing another specific configuration of the edge detection circuit. FIG. 10 is a block diagram showing another configuration of the motion detection circuit, FIGS. 11 and 12 are block diagrams showing another embodiment of the present invention, and FIG. 13 is a block diagram showing a conventional example. Explanation of reference numerals 1 ... Motion detection circuit, 2,27 ... Input terminal, 3,43 ... 1 frame memory, 4,12,22,45,47 ... Subtraction circuit, 5,23 ... L
PF, 6,13,24,40,48,49 …… Absolute value circuit, 7,14… Non-linear conversion circuit, 8,39 …… BPF, 9 …… Amplification circuit for ACC, 10 ……
Demodulation circuit, 11: 2 frame memory, 15, 42: Synthesis circuit, 16: Noise removal circuit, 17: Spatio-temporal processing circuit, 1
8,51,52,55 …… Adaptive conversion circuit, 19 …… Edge detection circuit,
20,26,50,53,54 …… Output terminal, 21,44,46 …… 1H memory,
25,41 …… Bit compression circuit, 28,29,30,31 …… Conversion circuit,
32 ... selection circuit, 33, 34, 35, 36 ... constant multiplier, 37 ...
Multiplier, 38 ... Coefficient generation circuit.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Tatsuo Nagata 292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Home Appliances Research Laboratory, Hitachi, Ltd. (56) References JP-A-63-90987 (JP, A) 1-318491 (JP, A) JP-A-1-2777094 (JP, A) JP-A-63-21093 (JP, A) JP-A-62-76890 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04N 9/77 H04N 7/01 H04N 11/04

Claims (3)

(57) [Claims] A motion detection circuit for detecting motion of an image from a digitized television signal; a spatio-temporal processing circuit for expanding a motion detection signal output from the motion detection circuit in a time and space direction; An edge detection circuit for detecting an edge portion of an image from the television signal; an output signal from the spatiotemporal processing circuit as an input signal; and an input signal corresponding to the level of the edge detection signal output from the edge detection circuit. An adaptive conversion circuit for converting the level of the signal and outputting the signal as a motion information signal, wherein the adaptive conversion circuit reduces the level of the output signal with respect to a certain level of the input signal as the level of the edge detection signal increases A motion information signal detection circuit having such conversion characteristics. 2. The adaptive conversion circuit has a plurality of conversion characteristics for level conversion of the input signal, and any one of the plurality of conversion characteristics according to an output signal level of the edge detection circuit. 2. The motion information signal detection circuit according to claim 1, wherein the motion information signal detection circuit operates by selecting. 3. The motion detection circuit is configured to receive an edge detection signal output from the edge detection circuit, and to reduce the output level of the motion detection signal as the edge detection signal increases. The motion information signal detection circuit according to claim 1, wherein: