CA1257690A - Apparatus for detecting movement in a television signal - Google Patents
Apparatus for detecting movement in a television signalInfo
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- CA1257690A CA1257690A CA000576717A CA576717A CA1257690A CA 1257690 A CA1257690 A CA 1257690A CA 000576717 A CA000576717 A CA 000576717A CA 576717 A CA576717 A CA 576717A CA 1257690 A CA1257690 A CA 1257690A
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- circuit
- movement
- picture element
- frame
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Abstract
ABSTRACT
There is disclosed a movement detecting apparatus for detecting a degree of movement contained in an input composite color television signal, comprising means for producing a frame difference signal between the input composite color television signal and a delayed composite color television signal, means for obtaining a high frequency brightness signal corresponding to the high frequency component of the brightness signal contained in the composite color television signal, and means for detecting the degree of movement in response to the frame difference signal and the high frequency brightness signal.
There is disclosed a movement detecting apparatus for detecting a degree of movement contained in an input composite color television signal, comprising means for producing a frame difference signal between the input composite color television signal and a delayed composite color television signal, means for obtaining a high frequency brightness signal corresponding to the high frequency component of the brightness signal contained in the composite color television signal, and means for detecting the degree of movement in response to the frame difference signal and the high frequency brightness signal.
Description
iP76~
APPARATUS FOR DETECTING MOVEMENT
IN A TELEVISION SIGNAL
Background of the Invention This invention relates to a movement detecting apparatus for detecting the degree of movemen-t contained in a television signal.
As processing circuits for a televisi.on signal, 'Lhere are known a noise reduction system using a frame-memory, an aaaptive Y/C separator, a scanning sequence converter, etc. One of the major subject matters to be solved in those apparatus is to successfully detect the degree of movement contained in the television signal.
In case of a monochromatic television signal, an interframe difference signal is calculated by using a rame memory, and the degree of movement is detected based on the level of the interframe difference signal.
On the other hand, in case of a composi-te color television signal, there is proposed a method that the polarity of a chrominance signal is inverted to match the phase of a color subcarrier in the NTSC system, and an interframe difference signal is calculated -to detect the degree of movement based on the level thereof. Such method is successful in detection broadly and is performed by a relative simple configuration. But it is unsuccessful in detection at the edge portion of an image. As an alternatlve, there is proposed a method by J. O. LIMB
and J.A. MURPH~ that is adapted to detect the velocity of moving images. This method is reported in "COMPUTER
GRAPHICS AND IMAGE PROCESSING", Apr. 1975, pp.311 - 327, by the title of "Estimating the Velocity of Moving Images in Television Signals". According to such a method, the speed S of moving images is determined by the following equation:
S = ~ ¦FDS~ EDS¦
MA MA
where FDS represents a frame difference signal, EDS
represents a picture element difference signal and MA
represents a moving area. ~ith this method, the speed can be detected correctly and movement judgment can be made also at the edge portion with no error. However, the method is disadvantageous in that it necessarily requires a larger configuration of a hardware when it is directly applied to processing of a television signal in a real time base, because the moving area must be first detected and the total sum of the respective difference signals must be then calculated for the moving area in the real -time base.
In prac-tice, it is not necessary -to detec-t a direction of movement when the moving detection is applied to the adaptive Y/C separator, the scanning sequence converter or the like. Further, in such appara-tus, it is also not necessary to precisely detect the speed of movement. When applying the moving detection to such apparatus, importan-t things are to know the approximate speed of moving area in the pic-ture and not to erron-eously judge an edge of a stationary image as a moving portion.
Summary of the Invention It is an object of the present invention to provide a movement detecting appara-tus which detects a movement contained in a television signal with a simple hardware conFiguration ar.d is ca~able of preverting an error moving detection at an edge portion of a stationary image.
According to one aspect of the present irvention, there is provided a movement detection apparatus for detecting the degree of movement of an image which is represented by a compo-site television signal having a brightness signal component and a chrominance signal component, said apparatus comprising: means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous brightness television signal, said frame difference means operat-ing independently of the direction of movement of picture elemen-ts of said image; means for producing a second frame difEerence sig-nal having a magnitude which is related to the difference between a present and previous chrominance signal, said frame difference producing means operating independently of the direction of move-ment of picture elements of said image; means for producing a first sum of picture element differences signal having a magnitude -3a- 66446-296D
which is related to the differences between the value of a given picture element and adjacent picture elemen-ts based on said bright-ness signal component of said television signal, said first sum of picture element differences means operating independently of the direction of movement of pic-ture elements of said image; means for producing a second sum of picture element differences signal having a magnitude which is related to the differences be-tween the value of a given picture element and adjacent picture elements based on the chrominance signal on said chrominance signal compon-ent of said television signal, said second sum of picture elementdifferences means operating independently of the direction of movement of picture elements of said image, and means for produc-ing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second pic-ture element differences signals.
-~- 66~6-296D
second frame difference signal based on said chrominance signal component, and an addition circuit for combining said first and second frame difference signals.
According to another aspect of the presen-t invention, there is provided a movement detection apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said appara-tus comprising: means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous bright-ness television signal, said frame difference means operating in-dependently of the direction of movement of picture elements of said image; means for producing a second frame difference signal having a magnitude which is related to the difference between a present and a previous chrominance signal, said frame difference producing means operating independently of the direction of move~
ment of picture elements of said image; means for producing a first sum of picture element differences signal having a magnitude which is relatecl to the differences between the value of a given picture element and adjacent picture elements based on a present frame, said first sum of picture element differences means operat-ing independently of the direction of movement of pic-ture elements of said image; means for producing a second sum of picture element differences signal having a magnitude which is related to the differences be-tween the value of a given picture element and adjacent picture elements based on a previous frame, said second sum of picture element differences means operating independently of the direction of movement of picture elements of said image;
-4a- 66446-296D
and means for producing an output which is indica-tive of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.
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-4~- 6946-296 wi-th reference to the accompanying drawings, in which:
Fig. 1 is a block diagram of a firs-t embodiment of the present invention;
Fig. 2 is a block diagram showing a picture element difference computing circui-t shown in Fig. l;
Fig. 3 shows examples of a conversion characteristic of a conversion circuit shown in Fig~ 5;
Fig. 4 shows other examples of the conversion char-acteristics of the conversion circuit;
Fig. 5 is a block diagram of a second embodiment of the present invention;
Fig. 6 is a block diagram showing a filter shown in Fig. 5;
Fig. 7 is a block diagram of a third embodiment of the present invention;
Fig. ~ shows a chrominance signal polarity inverting circuit shown in Fig. 7;
Fig. 9 is a block diagram of a fourth embodiment of the present invention;
Fig. 10 is a block diagram of a fif-th embodiment of the present invention;
~5~
Fig. 11 is a block diagram of a sixth embodiment of the present invention;
Fig. 12 shows a high frequency brightness signal extracting circuit used in the present invention;
Figs. 13 (a) and (b) show examples of input/output characteristics of a movement decision circuit shown in Fig. 11;
Fig. 14 is a block diagram of a seventh embodiment of the present invention;
Fig. 15 is a block diagram of an eighth embodiment of the present invention;
Fig. 16 shows another example of a high frequency brightness signal extracting circuit shown in Fig. 15;
Fig. 17 is a block diagram of a nineth embodiment of the present invention; and Figs. 1i3 and 19 show other examples of the input/
output characteristic of the movement decision cïrcuit shown in Fig. 14.
Preferred Embodiments of the Invention With reference to Fig. 1 showing a block diagram of a first embodiment of the present invention, a digital monochromatic television signal applied to an input terminal 1 is supplied to a subtractor 4, a frame memory 2 and a picture elemen-t diEference sum computing circuit 3.
APPARATUS FOR DETECTING MOVEMENT
IN A TELEVISION SIGNAL
Background of the Invention This invention relates to a movement detecting apparatus for detecting the degree of movemen-t contained in a television signal.
As processing circuits for a televisi.on signal, 'Lhere are known a noise reduction system using a frame-memory, an aaaptive Y/C separator, a scanning sequence converter, etc. One of the major subject matters to be solved in those apparatus is to successfully detect the degree of movement contained in the television signal.
In case of a monochromatic television signal, an interframe difference signal is calculated by using a rame memory, and the degree of movement is detected based on the level of the interframe difference signal.
On the other hand, in case of a composi-te color television signal, there is proposed a method that the polarity of a chrominance signal is inverted to match the phase of a color subcarrier in the NTSC system, and an interframe difference signal is calculated -to detect the degree of movement based on the level thereof. Such method is successful in detection broadly and is performed by a relative simple configuration. But it is unsuccessful in detection at the edge portion of an image. As an alternatlve, there is proposed a method by J. O. LIMB
and J.A. MURPH~ that is adapted to detect the velocity of moving images. This method is reported in "COMPUTER
GRAPHICS AND IMAGE PROCESSING", Apr. 1975, pp.311 - 327, by the title of "Estimating the Velocity of Moving Images in Television Signals". According to such a method, the speed S of moving images is determined by the following equation:
S = ~ ¦FDS~ EDS¦
MA MA
where FDS represents a frame difference signal, EDS
represents a picture element difference signal and MA
represents a moving area. ~ith this method, the speed can be detected correctly and movement judgment can be made also at the edge portion with no error. However, the method is disadvantageous in that it necessarily requires a larger configuration of a hardware when it is directly applied to processing of a television signal in a real time base, because the moving area must be first detected and the total sum of the respective difference signals must be then calculated for the moving area in the real -time base.
In prac-tice, it is not necessary -to detec-t a direction of movement when the moving detection is applied to the adaptive Y/C separator, the scanning sequence converter or the like. Further, in such appara-tus, it is also not necessary to precisely detect the speed of movement. When applying the moving detection to such apparatus, importan-t things are to know the approximate speed of moving area in the pic-ture and not to erron-eously judge an edge of a stationary image as a moving portion.
Summary of the Invention It is an object of the present invention to provide a movement detecting appara-tus which detects a movement contained in a television signal with a simple hardware conFiguration ar.d is ca~able of preverting an error moving detection at an edge portion of a stationary image.
According to one aspect of the present irvention, there is provided a movement detection apparatus for detecting the degree of movement of an image which is represented by a compo-site television signal having a brightness signal component and a chrominance signal component, said apparatus comprising: means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous brightness television signal, said frame difference means operat-ing independently of the direction of movement of picture elemen-ts of said image; means for producing a second frame difEerence sig-nal having a magnitude which is related to the difference between a present and previous chrominance signal, said frame difference producing means operating independently of the direction of move-ment of picture elements of said image; means for producing a first sum of picture element differences signal having a magnitude -3a- 66446-296D
which is related to the differences between the value of a given picture element and adjacent picture elemen-ts based on said bright-ness signal component of said television signal, said first sum of picture element differences means operating independently of the direction of movement of pic-ture elements of said image; means for producing a second sum of picture element differences signal having a magnitude which is related to the differences be-tween the value of a given picture element and adjacent picture elements based on the chrominance signal on said chrominance signal compon-ent of said television signal, said second sum of picture elementdifferences means operating independently of the direction of movement of picture elements of said image, and means for produc-ing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second pic-ture element differences signals.
-~- 66~6-296D
second frame difference signal based on said chrominance signal component, and an addition circuit for combining said first and second frame difference signals.
According to another aspect of the presen-t invention, there is provided a movement detection apparatus for detecting the degree of movement of an image which is represented by a composite television signal having a brightness signal component and a chrominance signal component, said appara-tus comprising: means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous bright-ness television signal, said frame difference means operating in-dependently of the direction of movement of picture elements of said image; means for producing a second frame difference signal having a magnitude which is related to the difference between a present and a previous chrominance signal, said frame difference producing means operating independently of the direction of move~
ment of picture elements of said image; means for producing a first sum of picture element differences signal having a magnitude which is relatecl to the differences between the value of a given picture element and adjacent picture elements based on a present frame, said first sum of picture element differences means operat-ing independently of the direction of movement of pic-ture elements of said image; means for producing a second sum of picture element differences signal having a magnitude which is related to the differences be-tween the value of a given picture element and adjacent picture elements based on a previous frame, said second sum of picture element differences means operating independently of the direction of movement of picture elements of said image;
-4a- 66446-296D
and means for producing an output which is indica-tive of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.
~i;7~
-4~- 6946-296 wi-th reference to the accompanying drawings, in which:
Fig. 1 is a block diagram of a firs-t embodiment of the present invention;
Fig. 2 is a block diagram showing a picture element difference computing circui-t shown in Fig. l;
Fig. 3 shows examples of a conversion characteristic of a conversion circuit shown in Fig~ 5;
Fig. 4 shows other examples of the conversion char-acteristics of the conversion circuit;
Fig. 5 is a block diagram of a second embodiment of the present invention;
Fig. 6 is a block diagram showing a filter shown in Fig. 5;
Fig. 7 is a block diagram of a third embodiment of the present invention;
Fig. ~ shows a chrominance signal polarity inverting circuit shown in Fig. 7;
Fig. 9 is a block diagram of a fourth embodiment of the present invention;
Fig. 10 is a block diagram of a fif-th embodiment of the present invention;
~5~
Fig. 11 is a block diagram of a sixth embodiment of the present invention;
Fig. 12 shows a high frequency brightness signal extracting circuit used in the present invention;
Figs. 13 (a) and (b) show examples of input/output characteristics of a movement decision circuit shown in Fig. 11;
Fig. 14 is a block diagram of a seventh embodiment of the present invention;
Fig. 15 is a block diagram of an eighth embodiment of the present invention;
Fig. 16 shows another example of a high frequency brightness signal extracting circuit shown in Fig. 15;
Fig. 17 is a block diagram of a nineth embodiment of the present invention; and Figs. 1i3 and 19 show other examples of the input/
output characteristic of the movement decision cïrcuit shown in Fig. 14.
Preferred Embodiments of the Invention With reference to Fig. 1 showing a block diagram of a first embodiment of the present invention, a digital monochromatic television signal applied to an input terminal 1 is supplied to a subtractor 4, a frame memory 2 and a picture elemen-t diEference sum computing circuit 3.
2~ ~he television signal delayed by one frame period through ~ ~i76~1~
the frame memory 2 is supplied to ~he subtractor 4 and the picture element difference sum computing circuit 3.
The subtractor ~ calculates a frame difference signal between the lnput television signal and the delayed television signal and supplies it to a conversion circuit 5.
The picture e~ement difference sum computing circuit 3 produces a picture element difference sum signal, i.e., the total sum of absolute values of plural differences between one picture element and other picture elements in the vicinity of the one picture element, whose movement is to be detected, for the present and previous frames, and then supplies it to the conversion circuit 5. In other words, a frame difference signal is obtained for one picture element, whose movement is to be detected, based on the frame difference between this picture element and the picture element in the previous frame at the same position.
Next, an accumulation value of the absolute values of differences between the picture element and respective front and back picture elements in the same line and between the picture element and respective picture elements having the same horizontal position and locating in upper and lower lines is calculated for the present frame and the previous frame, respectively. Then, the two calculated accumulation values for the presen-t and previous frames are added. rrhen -the frame difference signal and the added accumulation value (the picture element difference sum signal) are both supplied to the conversion clrcuit 5. In this case, when there is a relative delay difference between the frarne difference signal and the picture element difference sum signal, delay compensation is performed. F~nally, the conversion circui-t 5 obtains a signal indica~ing the degree of movement based on the frame difference signal and the picture element difference sum signal for each picture element, and -then supplies the signal to an output terminal 6.
Referring to Fig. 2 showing the picture element difference sum computing circuit 3 shown in Fig. 1, the digital television signal delivered from the input terminal tFig. 1) is supplied through an lnput terminal 7 to a line memory 3 and a subtractor 10 in a first picture element difference sum computing circuit 20. The signal delayed by one horizontal period through the line memory 8 is supplied to subtractors 10 and 11, and a delay circuit 9.
The line difference signal delivered from -the subtractor 10 is fed to an absolute value circuit 12 to obtain an absolute value, i.e., an absolute line difference signal thereof, which is supplied to a line memory 14 and an adder 16.
The absolute line difference signal delayed by one horizontal period through the line mernory 14 is supplied to the adder 16. The adder ou-tputs the sum of the two absolute line difference signals between present and :~2S;~
previous lines, and between present and following lines and supplies thesurn to an adder 19 -through a clelay circuit 18 for delay compensation. On the other hand, the signal delayed by one sampling period through the delay circuit 9 is supplied to a subtractor 11 which produces a sample difference signal. An absolute value circuit 13 outputs an absolute value, i.e., an absolute sample difference signal and supplies i-t to a delay circuit 15 and an adder 17. The absolute sample difference signal delivered from the absolute value circuit 13 is applied to a one sample delay 15 and an adder 17.
Therefore, the adder 17 adds the absolute sample difference signal between a front sample and the present sample and -the absolute sample difference signal between the present sample and a back sample, and outputs a sample difference sum signal to an adder 19. This sample difference sum signal is supplied to the adder 19.
Therefore, -the adder 19 outputs the sum of the line and sample difference signals relative to the upper, lower, front and back picture elements. The sum delivered from the adder 19 is supplied to an adder 23. A second picture element difference sum computing circuit 22 has the same configura-tion as -the first picture element difference sum computing circuit 20 and outputs a sum of line and sample difference signals relative -to the upper, lower, front and back picture elements in accordance with the delayed television signal which is applied to an input terminal 21 from the frame memory 2 (Fig. 1). The sum delivered from the circuit 22 is supplied to the adder 23. Thus, the adder 23 outputs a picture element difference surn signal for -two frames, which signal is supplied to an output terminal 24.
Fiy. 3 shows examples of conversion characteristics of the conversion circuit 5 shown in Fig. 1. The degree - of movement based on the frame difference signal y and the picture element difference sum signal x is divided into five steps from stillness M0 to complete movement M4 by using the function of y = f1(x), f2(x) and f3(x) f4(x) which represent the respective boundaries.
Since the frame difference signal and the picture element difference sum signal are not obtained herein from the entire moving area, it is difficult to determine a correct speed based on both signals. Therefore, a calculated value of the ratio y/x is used as an approximate value. The portion having the smal1 magnitude of the picture element difference sum signal x is assumed to be a flat portion and the degree of movement is decided mainly based on the magnitude of the frame difference signal. The por-tion having the large magnitude of the picture elemen-t difference sum signal can be regarded as a portion including many edge componen-ts, so that, taking the speed into account, the degree of movement is decided mainly based on the ratio of the frame difference signal to the picture element difference sum signa]. Threshold values Tl - T4 meet the relationship of Tl '-T2 ~ T3 ~ T4, and gradients Kl ~ K4 of fl(x) - f4(x) in the portion giving the larger _ meets the relationship of Kl ~ K2 c K3 ~ K4 .
The function of y = fl(x) is approximated by y = Ti when x is small and by y = Kix (where i = 1 - 4) when _ is large.
The conversion circuit 5 having the characteristics shown in Fig. 3 can be realized, for example, using a read only memory (ROM). As output signals indicating the degree of movement, there are issued by way of example signals "0" through "4" corresponding to -the degrees of movement M0 through M4.
Fig. 4 shows alternate examples of conversion characteristics of the conversion circuit 5 shown in Fig. 1. As compared with the characteristics shown in Fig. 3, the characteristics shown in Fig. 4 are such that the frame difference signal y and the picture element difference sum signal _ are limited in their magnitudes larger than a certain value. This makes it possible that, in case of realizing the conversion circuit using a ROM, the frame difference signal and the picture element difference sum signal are applied to addresses of -the ROM for conversion characteris-tics after belng limited to have the less number of bits, whereby the number of 76~
bits for input addresses of the ROM for conversion characteristics, i.e., the volume of ROM, can be reduced.
Such limitation accompanies an influence that the sensitivity of deciding rnovement is increased in the portion of larger Y~ and y, but this gives rise no problem in practical use.
Fig. 5 is a block diagram showing a second embodiment of the present invention. This embodiment is so arranged that movement detection of a color television signal in the NTSC system is performed using a frame difference signal of a brightness (Y) signal and the picture element difference sum of the Y signal within one frame. With this arrangement, accuracy of decision is somewhat lowered, but the volume of hardware can be reduced. A digital color television signal in the NTSC system sampled with a fourfold subcarrier fsc is applied to an input terminal 25 and supplied to a frarne memory 26, subtractor 27 and a picture element difference sum computing circuit 32.
The frame memory 26 delays the television signal by one frame periocl and outputs it to the sub-tractor 27.
The frame difference signal delivered from the subtractor 27 is supplied through a filter 28 which removes the component of the subcarrier f , to an absolute value ~ c circuit 29 which -takes an absolute value thereof. The absolute value delivered from the abso'ute value circuit 29 is supplied through a delay circuit 30 to a conversion ~5'7~
circuit 31 as the frame difference signal. The delay circuit 30 compensates a delay between the frame difference signal and a picture element difference signal, which is delivered from a picture element difference sum computing circuit 32. The picture element difference sum cornputing circuit 32 comprises line memories 33 and 34 for delaying the input signal by one line period, multipliers 35, 36, 37 and 44 having coefficients of -1/4, 1/2, -1/4, 1/2, respectively, adders 38, 43, 51 and 52, registers 39 and 42 for making delay of one sampling period, subtractors 40, 45 and 46, absolute value circuits 41, 49 and 50, and filters 47 and 48 for removing the component of the subcarrier fsc In the picture element difference sum computing circuit 32, a brightness (Y) signal is extracted from the input color television signal by a comb filter of a 2-line type, which comprises the line memories 33 and 34, multipliers 35, 36 and 37, and the adder 38. The Y signal delivered from the comb filter is transmi.tted to the combination of the regis-ters 39 and 42, the subtractor 40, and the adder 43. This combina-tion performs to produce the sum of sample difference signals as the same as Fig. 2.
On the other hand, the two signals delivered from the subtractors 45 and 46 are processed through the filters 47 and 48, and the absolute value circu.its 49 and 50 for producing line difference signals. The two line difference signals are added in the adder 51. The sum of the sample difference signals and the sum of the ~lne difference signals are added in the adder 52 and averaged in the multiplier 44 to produce the picture element difference sum signal. The picture element difference sum signal is supplied to the conversion circuit 31. The conversion circui~ 31 has the same f~nction as the conversion circuit 5 of Fig. 1, so that it outputs a signal indicating the degree of movement based on the frame difference signal and the picture element difference sum signal. It is to be noted that, if there is a phase difference between outputs delivered from the adders 43 and 51, phase correction must be implemented.
Fig. 6 shows an example of the filter 28 in Fig. ~.
The filter 28 is of a digital filter which comprises registers 55, 56, 57 and 58 for one sampling period delay, multipliers 60, 59 and 61 having coefficients of 1/4, 1/2 and 1/4, respectively, and an adder 62. I'he signal applied to an input terminal 54 is -transmi-tted at an output terminal 63 after the subcarrier componen-t has been removed -therefrom. The o-ther filters 47 and 48 in Fig. 5 also have the same configuration.
Fig. 7 shows a third embodiment of the present invention. In -this embodiment, when a frame difference signal is Produced, a chrominance signal polari-ty inverting circuit is used for cancelling chrominance components, In Fig. 7, a digital color television signal in the NTSC system sampled with 4 fsc and applied to an input terminal 64 is supplied to the chrominance signal polarity inverting circuit 65, a subtractor 67 and a picture element difference sum computing circuit 70.
The chrominance signal polarity inverting circuit 65 inverts the polarity of the color subcarrier signal of the color television signal and outpu-ts the inverted signal to a frame memory 66. The frame memory 66 transmits the delayed television signal to the subtractor 67.
In this case, the delay time due to the combination of the chrominance signal polarity inverting circuit 65 and the frame memory 66 is set to one frame period. The subtra 67 outputs the frame dif~erence signal. An absolute value circuit 68 receives the frame difference signal and produces an absolute value thereof. The absolute value is supplied through a delay circuit 69, which performs delay compensation, to a conversion circuit 71. The picture element difference sum computing circuit 70 has the same function as the picture element difference sum computing circuit 32 of F'ig. 5, so that it produces a picture element difference sum signal of the Y signal from the composite color television signal and transmits the produced sum signal to the conversion circui-t 71.
The conversion circuit 71 has the same function as -the conversion circuit 5 of Fig. 1, so that it outpu-ts a signal lndicating the degree of movement based on the frame difference signal and the picture element difference sum signal at its output terminal 72. Fig. 8 shows the construction of the chrominance signal polarity inverting circuit 65. The circuit 65 is of a digital filter which comprises line memories 74 and 75 for one hori~ontal scanning period delay, multipliers 76 and 77 having coefficien-ts of -l/2 and -l/2, adder 79, a band pass filter 80 for passing the frequency around fsc therethrough, and a subtractor 81. The band pass filter 80 can be realized, for example, by replacing the coefficients of the multipliers 60, 59 and 61 in the filter 28 of Fig. 6 with -l/4, l/2 and -l/4, respectively. As a result, the filter 80 has a characteristic to pass the f c component therethrough. Incidentially, the chrominance signal polarity inverting circuit 65 and the picture element difference sum computing circuit 70 may be arranged to have a common line memory. In case the frame difference of the C signal becomes larger due to cross talk of the high frequency brightness signal, the weight of the frame difference of the C signal is set smaller than one to reduce the detection sensitivity of movement with such frequency component.
Fig. 9 is a block diagram of a fourth embodiment of the present invention. In this embodiment, a frame difference signal is determined by adding a Y frame difference and a chrominance (C) frame difference. In this 6~
~,, case, a coefficient for adding the chrominance frame difference is adjusted to small value, for e~ampl.e, less than 1 . Furthermore, a picture element difference sum signal is determined for two frame periods, in this embodiment. In Fig. 9, a digital color -tel.evision signal in the NTSC system sampled with 4 fsc is supplied through an input terminal 83 to a subtractor 85, an aduer 86, a frame memory 84 and a first picture element difference sum computing circuit 92 of a picture element difference sum computing circuit 95. The frame memory 84 delays the input signal by one frame period and su~plies it to the subtractor 85, the adder 86 and a second picture element difference sum computing circuit 93. The subtractor 85 outputs a signal containing the Y frame difference and the C signal having a twofo~d magnitude to a filter 87. The filter 87 has characteristics to block the subcarrier frequency fsc and, therefore, output the frame difference signal of the Y signal to an adder 90. On the other hand, the adder 86 outpu-ts a signal containing the Y signal having a twofold magnitude and -the C frame difference -to a filter 88.
~he filter 88 has the characteristic to pass only the subcarrier fre~uency f~c and therefore, outputs the frame difference signal of the C signal to a multip]ier 89 having the coefficient K less -than 1 . A adder 90 adds ~he Y frame difference delivered from the filter 87 and the C frame difference delivered from the multiplier 89, and outputs a frame difference signal, as a result.
The frame difference signal is supplied to an absolute circuit 91. r~he absolute circuit 91 outputs the abso_ute value of the frame difference signal to a conversion circuit 96. The first and second picture element difference sum computing circuits 92 and 93 calculate the picture element difference sum for the previous and present frames, respectively, and transmit them to an adder 94. Therefore, the adder 94 outputs the resul-t as the picture element difference sum signal to the conversion circuit 96. The conversion circuit 96 produces a signal indicating the degree of movement based on the frame difference signal and the picture element difference sum signal, and then supplies it to an output terminal 97. In this case, when there lS
a time difference between the frame difference sign~' and picture element difference sum signal, a delay circuit is inserted between -the blocks 90 and 96. It is -to be noted that the filter 87, the filter 88, the first and second picture element difference sum computing circuits 92 and 93, and the conversion circuit 96 have the same construction as the filter 28 in Fig. 5, the filter 80 in Fig. 8, the first picture e]ement difference sum computing circuit 32 in Fig. 5 and the conversion circuit 5 in Fig. 1, respectively.
6~
Fig. 10 is a block diagram of a fifth embodiment of the present invention. In this embodiment, a smoothing circuit 93 is added to the embodiment of Fig. 9 so as to smooth the signal indicating the degree of movement.
The smoothing circuit 98 checks signals in the vicinity of the present signal indicating the movement, for example, checks the front, back, upper and lower four samples of the signal inaicating the movement, so that, in case where the present signal indicating complete moving is isolated among the signals indicating standstill, the present signal is decided to be standstill and, in the opposite case, it is decided to be moving. As an alternate smoothing method, a filter may be added for the frame difference signal in Figs. 1 and 7 to perform the desired smoothing.
The picture element difference sum computing circuit 3 in Fig. 2 can be modified. For example, the difference relative to only the upper picture element in the vertical direction may be used to avoid larger relative delay with respect to the frame difference signal and, as a result, a hardware is further simplified. Further, if only the absolute value of picture element difference relative to the front sample in the present frame is used, a further simplified hardware is adapted. When the numbers of samples, i.e., the number of differences between picture elements for producing -the picture elemen-t difference sum i7~
signal is varied, it is required to adjust -the eoeffieients, gains or the conversion characteristics correspondingly beeause the average magnitude of the pieture element difference sum signal is also varied. When the picture element diEference sum signal is produced by adding plural differences between picture elements, weighting for each difference may be varied in accordance with a picture element pieture. E'urther, eonversion charaeteristies as shown in Figs. 3 and 4 may be modified. When the conversion characteristic is determined, it is also possible that two aetual standstill frames of a image are gradually shifted from eaeh other, and the relationship between the frame differenee signal and the pieture element differenee sum signal at respeetive shifted positions is practically obtained ~or many picture elements in a statistic fashion thereby to determine the conversion characteristic.
While the frame difference of the Y signal and the K-multiplied frame difference of the C signal are added to produce the frame difference signal in the embodimen-ts of Figs. 9 and 10, such addition may be effected af-ter taking absolute values of the respective signals. In this ease, there ean be attained improved aecuracy when the detection result is applied to an adaptive Y/C
separation because the frame difference signal includes both the Y frame difference information and the C frame difference information. Further, detection of movement ~7~
may be perEormed based on three siynals, i.e~, the Y frame difference, the C frame difference and the picture element difference sum signal.
In the embodiments described above, the moving detection is performed by evaluating the frame difference sicnal under the plcture element difference sum signal.
More simplified methods will be described in following embodiMents, in which the moving detection is performed by evaluating the frame difference signal under the level of a high frequency component in a television signal.
Referring to Fig. 11 showing a sixth embodiment, a color television signal of the NTSC system is applied through an input terminal 99 -to a frame memory 100.
The chrominance (C) signal contained in the delayed television signal delivered from the frame memory 100 is inverted in its polarity by a chrominance polarity inverting circuit 101 to have the same polarity as the input television signal. The difference between the input television signal and the delayed television signal from the frame memory 100 is calculated by a subtraction circuit 103 to ob-tain a frame difference signal which is supplied to a movement decision circuit 10~. The input television signal is also supplied to a high frequency brightness signal extracting circuit 102, by which the signal corresponding to the high frequency component of a brightness (Y) signal is extracted -to be supplied to 7~
the movement decision circuit 104. The movement decision circuit 104 is arranged to control the level of the frame difference signal in accordance with the magnitude of high frequency Y signal, so that the frame difference signal subjected to the level control is delivered as a movement information signal.
Fig. 12 shows a block diagram of the high frequency brightness signal extracting circuit 102 in Fig. 11.
This examplified circuit is arranged so as -to extract a high frequency Y signal by using a comb-like filter including two line memories 107 and 108 and a high pass filter 116. The color television signal applied to an input terminal 106 is delayed through line memories 107 and 108 by one horizontal period, respectively.
Multipliers 109, 110 and 111 have coefficients of -1/4, 1/2 and -1/4, respectively. The multiplied outputs are added by an adder 112 and then supplied to a band pass filter 114. The band pass filter 114 passes only the signal around the color subcarrier frequency f6c therethrough and then transmits -the ex-tracted color subcarrier (C) signal to a subtractor 115. The composite color television siynal delivered from the line memory 107 is delayed by a delay circuit 113 to be matched with delay of -the C signal and then supplied to -the subtractor 115.
In the subtractor 115, the C signal is sub-tracted from the composite color television signal. to obtain only -the 6~
Y signal. The extracted Y signal is supplied to a high pass filter 116, in which the high frequency Y signal is extracted and supplied to an output terminal 117.
Figs. 13 (a) and (b) show characteristics of the movement decision clrcuit 104. In Fig. 13(a), the relationship between the magnitude _ of the frame difference signal and the magnitude y of a movement detection signal is shown, and the func-tion of y = f(x) is represented by a linear line of y = kx (where k is a gradient) in this case. The gradient _ is dependent on the magnitude x of the high frequency Y signal, and Fig. 13(b) illustrates the relationship between the magnitude z of high frequency Y signal and the gradient k.
Namely, as the magnitude z of high frequency Y signal becomes larger, the gradient k becomes smaller less than one. In other words, when the magnitude of the high frequency Y signal is larger, the magnitude of frame difference signal is attenuated to obtain -the movement de-tection signal. The movement decision circuit 104 having the characteristic shown in Fig. 13 can be easily realized by using a read only memory (ROM), which stores the relationshi.p between the frame difference signal and the high frequency Y signal. Therefore, the frame difference signal and the high frequency Y signal are applied to -the ROM as addresses, and the movement detection signal is delivered from -the ROM.
- 23 - ~ ~S ~
Fig. 14 is a block diagram of a seventh embodiment of the present invention. In this embodiment, the frame difference signal is obtained by adding the frame difference of the Y signal and the frame difference of the C signal. ~ composite color -television signal applied to an inpu-t terminal 118 is supplied to a subtractor 121, an adder 122, a frame memory 119 and a high frequency brightness signal extracting circuit 120.
The combination of the frame memory 119, the subtractor 121, the adder 122, filters 123 and 124, a multiplier 125 and an adder 126 is built up for extracting the frame difference signal containing the Y frame difference and the C frame difference, and already explained in Fig. 9. In this case, the coefficient of the multiplier 125 is set to "1".
Of course, it in possible to change the coefficient value of the multiplier 125 for changing the weight of the C
frame difference. The high frequency brightness signal extracting circuit 120 has the same construction as that of Fig. 12, and transmits the high frequency component of the Y signal to a movement decision circuit 127. The movement decision circuit 127 has the same func-tion as the movement decision circuit 104 in Fig. 11, so that the movement detec-tion signal is delivered at an output terminal 129.
Referring now to F'ig. 15 showing an eighth embodiment of the presen-t invention, -this embodiment is arranged that - 24 - ~ ~7~
a chrominance (C) signal is ignored to sirnplify a circuit configuration by taking into account that the brightness (Y) signal has a major influence upon the detection of movement. A frame-memory 131, a high frequency brightness signal extrac-ting circuit 132, a subtractor 133, a fil-ter 13~ and a movement decision circuit 135 have -the sarne function as the frame memory 119, the high frequency brightness signal extracting circuit 120, the subtractor 121, the filter 123 and the movement decision circuit 127, respectively, and operate in a similar manner correspondingly.
In other words, this is corresponds to the case where the coefficient of the multiplier 125 is set zero in Fig. 14.
Fig. 16 shows another example of the high frequency brightness signal extracting circuit 132 in Fig. 15.
In Fig. 16, in order to simply obtain a high frequency Y signal without using a line memory, there is employed a filter 156 for blocking the signals in the vicinity of zero frequency and the subcarrier frequency. The filter 156 comprises delay circuit 137, 139 and 1~0 each for one sampling period delay, a subtractor 133 and an adder 1~1. The high frequency Y signal delivered from the filter 156 is fed to an absolu-te circuit 142 to take -the absolute value thereof. The absolute value is Eed to a delay circuit 143 having one sampling period delay and an adder 144. The adder adds the absolute values from the delay circuit 143 and the absolute circuit 1~2.
Further, an average value lS delivered from a multlplier 162 having a coefficient of 1/2.
Fig. 17 is a block diagram of a nineth embodiment of the present invention. This embodiment is provided for detecting the movement a monochromatic television signal. A monochroma-tic television signal from an input terminal 145 is supplied to a frame memory 146, and a sub-tractor 147. The subtractor 147 produces a frame difference signal. The frame difference signal is supplied through a delay circuit 157 to a movement decision circuit 154. In a high frequency brightness signal extracting circuit 148, delay circuits 149 and 151 each having one sampling period delay, subtractors 150 and 152 and a multiplier 158 having coefficient of 1/4 compose a filter having a transmission function H(z) represented by z-conversion as follows:
I~(z) = 1/4 (_z-2 + 2z-1 - 1) The high frequency Y signal delivered from the multiplier 158 is fed to an absolute circuit 153. The absolute value 20 from the circuit 153 is fed to a delay circuit 159 and, adder 160, and,then, a multiplier 161 having coefficient of 1/2 produces an average value. This average value is supplied to the movement decision circuit 154. The movement decision circuit 154 has the same function as 25 the movement decision circui-t 104 in Fig. 11, so that i-t outputs a signal indicating the degree of movemen-t to an ~utput terminal 155.
In Fig. 11, -the chrominance signal polarity inverting circuit 101 may be replaced by the frame memory 100, in their positions in Fig. 11, thus making it possible for a line memory necessary for the high frequency brightness signal extracting circuit 102 to be used commonly. As an alternative, a high frequency Y signal for ~he moving detection may be extracted from the signal delivered from the frame memory. In Figs. 11 and 1~, when there is a delay difference between the frame difference signal and the high frequency Y signal, a proper delay circuit should be inserted into either signal line. When the high frequency Y signal is used for the moving detection, it is alternatively possible to use its power value or it level average value of previous and subsequent several samples.
In the embodiments of Figs. 11 and 14, the movement detection signal obtained at each of the output terminals 105 and 129 has zero in the standstill image area and has a certain amplitude in the moving image area. To classify the image into several steps from stillness to full movement in accordance with the degree of movement, the amplitude of the movement detection signal is compared with several proper threshold values for determining one of the steps.
While the function y = f(x) shown in Flg. 13(a) was linear, a non-linear characteristic may be also used such ~5~
-that the frame difference signal less than a certain value is regarded as noise and the movement detection signal of zero is delivered in this region as shown in Fig. 18.
In the embodiment of Pig. 14, the frame difference signal is obtained by adding the Y frame difference and the C frame difference. On this occasion, it is not necessarily required to coincide weighting factors of the two frame differences. In fact, the C frame difference is apt to be larger than the Y frame difference even when the brightness (Y) and chrominance (C) signals contain the same movement because a cross talk of the high frequency Y signal, a jitter, etc. are con-tained in the television signal. Therefore, it is preferred to make the weighting factor of the C difference smaller, for example, less than "1".
While the conversion circuit 128 was composed of the adder 126 and the movement decision circuit 127 in the embodi~ent of Fig. 14, it can be also realized by using a read only memory (ROM). Furthermore, three types of input/output characteris-tics of f5(x), f6(x) and f7(x) as shown in Fig. 19 are prepared, and one characteristic is selected in accordance with the magnitude of high frequency Y signal.
As fully described in -the above, -the present invention permits correct detection of movement for - 28 - ~ ~5~
a monochromatic signal and a color television signal including the edge portion. Therefore, the present invention can be applied to various video signal processing circuits, such as an adaptive Y/C separator and scanning sequence converter, which utilize movement information of images.
the frame memory 2 is supplied to ~he subtractor 4 and the picture element difference sum computing circuit 3.
The subtractor ~ calculates a frame difference signal between the lnput television signal and the delayed television signal and supplies it to a conversion circuit 5.
The picture e~ement difference sum computing circuit 3 produces a picture element difference sum signal, i.e., the total sum of absolute values of plural differences between one picture element and other picture elements in the vicinity of the one picture element, whose movement is to be detected, for the present and previous frames, and then supplies it to the conversion circuit 5. In other words, a frame difference signal is obtained for one picture element, whose movement is to be detected, based on the frame difference between this picture element and the picture element in the previous frame at the same position.
Next, an accumulation value of the absolute values of differences between the picture element and respective front and back picture elements in the same line and between the picture element and respective picture elements having the same horizontal position and locating in upper and lower lines is calculated for the present frame and the previous frame, respectively. Then, the two calculated accumulation values for the presen-t and previous frames are added. rrhen -the frame difference signal and the added accumulation value (the picture element difference sum signal) are both supplied to the conversion clrcuit 5. In this case, when there is a relative delay difference between the frarne difference signal and the picture element difference sum signal, delay compensation is performed. F~nally, the conversion circui-t 5 obtains a signal indica~ing the degree of movement based on the frame difference signal and the picture element difference sum signal for each picture element, and -then supplies the signal to an output terminal 6.
Referring to Fig. 2 showing the picture element difference sum computing circuit 3 shown in Fig. 1, the digital television signal delivered from the input terminal tFig. 1) is supplied through an lnput terminal 7 to a line memory 3 and a subtractor 10 in a first picture element difference sum computing circuit 20. The signal delayed by one horizontal period through the line memory 8 is supplied to subtractors 10 and 11, and a delay circuit 9.
The line difference signal delivered from -the subtractor 10 is fed to an absolute value circuit 12 to obtain an absolute value, i.e., an absolute line difference signal thereof, which is supplied to a line memory 14 and an adder 16.
The absolute line difference signal delayed by one horizontal period through the line mernory 14 is supplied to the adder 16. The adder ou-tputs the sum of the two absolute line difference signals between present and :~2S;~
previous lines, and between present and following lines and supplies thesurn to an adder 19 -through a clelay circuit 18 for delay compensation. On the other hand, the signal delayed by one sampling period through the delay circuit 9 is supplied to a subtractor 11 which produces a sample difference signal. An absolute value circuit 13 outputs an absolute value, i.e., an absolute sample difference signal and supplies i-t to a delay circuit 15 and an adder 17. The absolute sample difference signal delivered from the absolute value circuit 13 is applied to a one sample delay 15 and an adder 17.
Therefore, the adder 17 adds the absolute sample difference signal between a front sample and the present sample and -the absolute sample difference signal between the present sample and a back sample, and outputs a sample difference sum signal to an adder 19. This sample difference sum signal is supplied to the adder 19.
Therefore, -the adder 19 outputs the sum of the line and sample difference signals relative to the upper, lower, front and back picture elements. The sum delivered from the adder 19 is supplied to an adder 23. A second picture element difference sum computing circuit 22 has the same configura-tion as -the first picture element difference sum computing circuit 20 and outputs a sum of line and sample difference signals relative -to the upper, lower, front and back picture elements in accordance with the delayed television signal which is applied to an input terminal 21 from the frame memory 2 (Fig. 1). The sum delivered from the circuit 22 is supplied to the adder 23. Thus, the adder 23 outputs a picture element difference surn signal for -two frames, which signal is supplied to an output terminal 24.
Fiy. 3 shows examples of conversion characteristics of the conversion circuit 5 shown in Fig. 1. The degree - of movement based on the frame difference signal y and the picture element difference sum signal x is divided into five steps from stillness M0 to complete movement M4 by using the function of y = f1(x), f2(x) and f3(x) f4(x) which represent the respective boundaries.
Since the frame difference signal and the picture element difference sum signal are not obtained herein from the entire moving area, it is difficult to determine a correct speed based on both signals. Therefore, a calculated value of the ratio y/x is used as an approximate value. The portion having the smal1 magnitude of the picture element difference sum signal x is assumed to be a flat portion and the degree of movement is decided mainly based on the magnitude of the frame difference signal. The por-tion having the large magnitude of the picture elemen-t difference sum signal can be regarded as a portion including many edge componen-ts, so that, taking the speed into account, the degree of movement is decided mainly based on the ratio of the frame difference signal to the picture element difference sum signa]. Threshold values Tl - T4 meet the relationship of Tl '-T2 ~ T3 ~ T4, and gradients Kl ~ K4 of fl(x) - f4(x) in the portion giving the larger _ meets the relationship of Kl ~ K2 c K3 ~ K4 .
The function of y = fl(x) is approximated by y = Ti when x is small and by y = Kix (where i = 1 - 4) when _ is large.
The conversion circuit 5 having the characteristics shown in Fig. 3 can be realized, for example, using a read only memory (ROM). As output signals indicating the degree of movement, there are issued by way of example signals "0" through "4" corresponding to -the degrees of movement M0 through M4.
Fig. 4 shows alternate examples of conversion characteristics of the conversion circuit 5 shown in Fig. 1. As compared with the characteristics shown in Fig. 3, the characteristics shown in Fig. 4 are such that the frame difference signal y and the picture element difference sum signal _ are limited in their magnitudes larger than a certain value. This makes it possible that, in case of realizing the conversion circuit using a ROM, the frame difference signal and the picture element difference sum signal are applied to addresses of -the ROM for conversion characteris-tics after belng limited to have the less number of bits, whereby the number of 76~
bits for input addresses of the ROM for conversion characteristics, i.e., the volume of ROM, can be reduced.
Such limitation accompanies an influence that the sensitivity of deciding rnovement is increased in the portion of larger Y~ and y, but this gives rise no problem in practical use.
Fig. 5 is a block diagram showing a second embodiment of the present invention. This embodiment is so arranged that movement detection of a color television signal in the NTSC system is performed using a frame difference signal of a brightness (Y) signal and the picture element difference sum of the Y signal within one frame. With this arrangement, accuracy of decision is somewhat lowered, but the volume of hardware can be reduced. A digital color television signal in the NTSC system sampled with a fourfold subcarrier fsc is applied to an input terminal 25 and supplied to a frarne memory 26, subtractor 27 and a picture element difference sum computing circuit 32.
The frame memory 26 delays the television signal by one frame periocl and outputs it to the sub-tractor 27.
The frame difference signal delivered from the subtractor 27 is supplied through a filter 28 which removes the component of the subcarrier f , to an absolute value ~ c circuit 29 which -takes an absolute value thereof. The absolute value delivered from the abso'ute value circuit 29 is supplied through a delay circuit 30 to a conversion ~5'7~
circuit 31 as the frame difference signal. The delay circuit 30 compensates a delay between the frame difference signal and a picture element difference signal, which is delivered from a picture element difference sum computing circuit 32. The picture element difference sum cornputing circuit 32 comprises line memories 33 and 34 for delaying the input signal by one line period, multipliers 35, 36, 37 and 44 having coefficients of -1/4, 1/2, -1/4, 1/2, respectively, adders 38, 43, 51 and 52, registers 39 and 42 for making delay of one sampling period, subtractors 40, 45 and 46, absolute value circuits 41, 49 and 50, and filters 47 and 48 for removing the component of the subcarrier fsc In the picture element difference sum computing circuit 32, a brightness (Y) signal is extracted from the input color television signal by a comb filter of a 2-line type, which comprises the line memories 33 and 34, multipliers 35, 36 and 37, and the adder 38. The Y signal delivered from the comb filter is transmi.tted to the combination of the regis-ters 39 and 42, the subtractor 40, and the adder 43. This combina-tion performs to produce the sum of sample difference signals as the same as Fig. 2.
On the other hand, the two signals delivered from the subtractors 45 and 46 are processed through the filters 47 and 48, and the absolute value circu.its 49 and 50 for producing line difference signals. The two line difference signals are added in the adder 51. The sum of the sample difference signals and the sum of the ~lne difference signals are added in the adder 52 and averaged in the multiplier 44 to produce the picture element difference sum signal. The picture element difference sum signal is supplied to the conversion circuit 31. The conversion circui~ 31 has the same f~nction as the conversion circuit 5 of Fig. 1, so that it outputs a signal indicating the degree of movement based on the frame difference signal and the picture element difference sum signal. It is to be noted that, if there is a phase difference between outputs delivered from the adders 43 and 51, phase correction must be implemented.
Fig. 6 shows an example of the filter 28 in Fig. ~.
The filter 28 is of a digital filter which comprises registers 55, 56, 57 and 58 for one sampling period delay, multipliers 60, 59 and 61 having coefficients of 1/4, 1/2 and 1/4, respectively, and an adder 62. I'he signal applied to an input terminal 54 is -transmi-tted at an output terminal 63 after the subcarrier componen-t has been removed -therefrom. The o-ther filters 47 and 48 in Fig. 5 also have the same configuration.
Fig. 7 shows a third embodiment of the present invention. In -this embodiment, when a frame difference signal is Produced, a chrominance signal polari-ty inverting circuit is used for cancelling chrominance components, In Fig. 7, a digital color television signal in the NTSC system sampled with 4 fsc and applied to an input terminal 64 is supplied to the chrominance signal polarity inverting circuit 65, a subtractor 67 and a picture element difference sum computing circuit 70.
The chrominance signal polarity inverting circuit 65 inverts the polarity of the color subcarrier signal of the color television signal and outpu-ts the inverted signal to a frame memory 66. The frame memory 66 transmits the delayed television signal to the subtractor 67.
In this case, the delay time due to the combination of the chrominance signal polarity inverting circuit 65 and the frame memory 66 is set to one frame period. The subtra 67 outputs the frame dif~erence signal. An absolute value circuit 68 receives the frame difference signal and produces an absolute value thereof. The absolute value is supplied through a delay circuit 69, which performs delay compensation, to a conversion circuit 71. The picture element difference sum computing circuit 70 has the same function as the picture element difference sum computing circuit 32 of F'ig. 5, so that it produces a picture element difference sum signal of the Y signal from the composite color television signal and transmits the produced sum signal to the conversion circui-t 71.
The conversion circuit 71 has the same function as -the conversion circuit 5 of Fig. 1, so that it outpu-ts a signal lndicating the degree of movement based on the frame difference signal and the picture element difference sum signal at its output terminal 72. Fig. 8 shows the construction of the chrominance signal polarity inverting circuit 65. The circuit 65 is of a digital filter which comprises line memories 74 and 75 for one hori~ontal scanning period delay, multipliers 76 and 77 having coefficien-ts of -l/2 and -l/2, adder 79, a band pass filter 80 for passing the frequency around fsc therethrough, and a subtractor 81. The band pass filter 80 can be realized, for example, by replacing the coefficients of the multipliers 60, 59 and 61 in the filter 28 of Fig. 6 with -l/4, l/2 and -l/4, respectively. As a result, the filter 80 has a characteristic to pass the f c component therethrough. Incidentially, the chrominance signal polarity inverting circuit 65 and the picture element difference sum computing circuit 70 may be arranged to have a common line memory. In case the frame difference of the C signal becomes larger due to cross talk of the high frequency brightness signal, the weight of the frame difference of the C signal is set smaller than one to reduce the detection sensitivity of movement with such frequency component.
Fig. 9 is a block diagram of a fourth embodiment of the present invention. In this embodiment, a frame difference signal is determined by adding a Y frame difference and a chrominance (C) frame difference. In this 6~
~,, case, a coefficient for adding the chrominance frame difference is adjusted to small value, for e~ampl.e, less than 1 . Furthermore, a picture element difference sum signal is determined for two frame periods, in this embodiment. In Fig. 9, a digital color -tel.evision signal in the NTSC system sampled with 4 fsc is supplied through an input terminal 83 to a subtractor 85, an aduer 86, a frame memory 84 and a first picture element difference sum computing circuit 92 of a picture element difference sum computing circuit 95. The frame memory 84 delays the input signal by one frame period and su~plies it to the subtractor 85, the adder 86 and a second picture element difference sum computing circuit 93. The subtractor 85 outputs a signal containing the Y frame difference and the C signal having a twofo~d magnitude to a filter 87. The filter 87 has characteristics to block the subcarrier frequency fsc and, therefore, output the frame difference signal of the Y signal to an adder 90. On the other hand, the adder 86 outpu-ts a signal containing the Y signal having a twofold magnitude and -the C frame difference -to a filter 88.
~he filter 88 has the characteristic to pass only the subcarrier fre~uency f~c and therefore, outputs the frame difference signal of the C signal to a multip]ier 89 having the coefficient K less -than 1 . A adder 90 adds ~he Y frame difference delivered from the filter 87 and the C frame difference delivered from the multiplier 89, and outputs a frame difference signal, as a result.
The frame difference signal is supplied to an absolute circuit 91. r~he absolute circuit 91 outputs the abso_ute value of the frame difference signal to a conversion circuit 96. The first and second picture element difference sum computing circuits 92 and 93 calculate the picture element difference sum for the previous and present frames, respectively, and transmit them to an adder 94. Therefore, the adder 94 outputs the resul-t as the picture element difference sum signal to the conversion circuit 96. The conversion circuit 96 produces a signal indicating the degree of movement based on the frame difference signal and the picture element difference sum signal, and then supplies it to an output terminal 97. In this case, when there lS
a time difference between the frame difference sign~' and picture element difference sum signal, a delay circuit is inserted between -the blocks 90 and 96. It is -to be noted that the filter 87, the filter 88, the first and second picture element difference sum computing circuits 92 and 93, and the conversion circuit 96 have the same construction as the filter 28 in Fig. 5, the filter 80 in Fig. 8, the first picture e]ement difference sum computing circuit 32 in Fig. 5 and the conversion circuit 5 in Fig. 1, respectively.
6~
Fig. 10 is a block diagram of a fifth embodiment of the present invention. In this embodiment, a smoothing circuit 93 is added to the embodiment of Fig. 9 so as to smooth the signal indicating the degree of movement.
The smoothing circuit 98 checks signals in the vicinity of the present signal indicating the movement, for example, checks the front, back, upper and lower four samples of the signal inaicating the movement, so that, in case where the present signal indicating complete moving is isolated among the signals indicating standstill, the present signal is decided to be standstill and, in the opposite case, it is decided to be moving. As an alternate smoothing method, a filter may be added for the frame difference signal in Figs. 1 and 7 to perform the desired smoothing.
The picture element difference sum computing circuit 3 in Fig. 2 can be modified. For example, the difference relative to only the upper picture element in the vertical direction may be used to avoid larger relative delay with respect to the frame difference signal and, as a result, a hardware is further simplified. Further, if only the absolute value of picture element difference relative to the front sample in the present frame is used, a further simplified hardware is adapted. When the numbers of samples, i.e., the number of differences between picture elements for producing -the picture elemen-t difference sum i7~
signal is varied, it is required to adjust -the eoeffieients, gains or the conversion characteristics correspondingly beeause the average magnitude of the pieture element difference sum signal is also varied. When the picture element diEference sum signal is produced by adding plural differences between picture elements, weighting for each difference may be varied in accordance with a picture element pieture. E'urther, eonversion charaeteristies as shown in Figs. 3 and 4 may be modified. When the conversion characteristic is determined, it is also possible that two aetual standstill frames of a image are gradually shifted from eaeh other, and the relationship between the frame differenee signal and the pieture element differenee sum signal at respeetive shifted positions is practically obtained ~or many picture elements in a statistic fashion thereby to determine the conversion characteristic.
While the frame difference of the Y signal and the K-multiplied frame difference of the C signal are added to produce the frame difference signal in the embodimen-ts of Figs. 9 and 10, such addition may be effected af-ter taking absolute values of the respective signals. In this ease, there ean be attained improved aecuracy when the detection result is applied to an adaptive Y/C
separation because the frame difference signal includes both the Y frame difference information and the C frame difference information. Further, detection of movement ~7~
may be perEormed based on three siynals, i.e~, the Y frame difference, the C frame difference and the picture element difference sum signal.
In the embodiments described above, the moving detection is performed by evaluating the frame difference sicnal under the plcture element difference sum signal.
More simplified methods will be described in following embodiMents, in which the moving detection is performed by evaluating the frame difference signal under the level of a high frequency component in a television signal.
Referring to Fig. 11 showing a sixth embodiment, a color television signal of the NTSC system is applied through an input terminal 99 -to a frame memory 100.
The chrominance (C) signal contained in the delayed television signal delivered from the frame memory 100 is inverted in its polarity by a chrominance polarity inverting circuit 101 to have the same polarity as the input television signal. The difference between the input television signal and the delayed television signal from the frame memory 100 is calculated by a subtraction circuit 103 to ob-tain a frame difference signal which is supplied to a movement decision circuit 10~. The input television signal is also supplied to a high frequency brightness signal extracting circuit 102, by which the signal corresponding to the high frequency component of a brightness (Y) signal is extracted -to be supplied to 7~
the movement decision circuit 104. The movement decision circuit 104 is arranged to control the level of the frame difference signal in accordance with the magnitude of high frequency Y signal, so that the frame difference signal subjected to the level control is delivered as a movement information signal.
Fig. 12 shows a block diagram of the high frequency brightness signal extracting circuit 102 in Fig. 11.
This examplified circuit is arranged so as -to extract a high frequency Y signal by using a comb-like filter including two line memories 107 and 108 and a high pass filter 116. The color television signal applied to an input terminal 106 is delayed through line memories 107 and 108 by one horizontal period, respectively.
Multipliers 109, 110 and 111 have coefficients of -1/4, 1/2 and -1/4, respectively. The multiplied outputs are added by an adder 112 and then supplied to a band pass filter 114. The band pass filter 114 passes only the signal around the color subcarrier frequency f6c therethrough and then transmits -the ex-tracted color subcarrier (C) signal to a subtractor 115. The composite color television siynal delivered from the line memory 107 is delayed by a delay circuit 113 to be matched with delay of -the C signal and then supplied to -the subtractor 115.
In the subtractor 115, the C signal is sub-tracted from the composite color television signal. to obtain only -the 6~
Y signal. The extracted Y signal is supplied to a high pass filter 116, in which the high frequency Y signal is extracted and supplied to an output terminal 117.
Figs. 13 (a) and (b) show characteristics of the movement decision clrcuit 104. In Fig. 13(a), the relationship between the magnitude _ of the frame difference signal and the magnitude y of a movement detection signal is shown, and the func-tion of y = f(x) is represented by a linear line of y = kx (where k is a gradient) in this case. The gradient _ is dependent on the magnitude x of the high frequency Y signal, and Fig. 13(b) illustrates the relationship between the magnitude z of high frequency Y signal and the gradient k.
Namely, as the magnitude z of high frequency Y signal becomes larger, the gradient k becomes smaller less than one. In other words, when the magnitude of the high frequency Y signal is larger, the magnitude of frame difference signal is attenuated to obtain -the movement de-tection signal. The movement decision circuit 104 having the characteristic shown in Fig. 13 can be easily realized by using a read only memory (ROM), which stores the relationshi.p between the frame difference signal and the high frequency Y signal. Therefore, the frame difference signal and the high frequency Y signal are applied to -the ROM as addresses, and the movement detection signal is delivered from -the ROM.
- 23 - ~ ~S ~
Fig. 14 is a block diagram of a seventh embodiment of the present invention. In this embodiment, the frame difference signal is obtained by adding the frame difference of the Y signal and the frame difference of the C signal. ~ composite color -television signal applied to an inpu-t terminal 118 is supplied to a subtractor 121, an adder 122, a frame memory 119 and a high frequency brightness signal extracting circuit 120.
The combination of the frame memory 119, the subtractor 121, the adder 122, filters 123 and 124, a multiplier 125 and an adder 126 is built up for extracting the frame difference signal containing the Y frame difference and the C frame difference, and already explained in Fig. 9. In this case, the coefficient of the multiplier 125 is set to "1".
Of course, it in possible to change the coefficient value of the multiplier 125 for changing the weight of the C
frame difference. The high frequency brightness signal extracting circuit 120 has the same construction as that of Fig. 12, and transmits the high frequency component of the Y signal to a movement decision circuit 127. The movement decision circuit 127 has the same func-tion as the movement decision circuit 104 in Fig. 11, so that the movement detec-tion signal is delivered at an output terminal 129.
Referring now to F'ig. 15 showing an eighth embodiment of the presen-t invention, -this embodiment is arranged that - 24 - ~ ~7~
a chrominance (C) signal is ignored to sirnplify a circuit configuration by taking into account that the brightness (Y) signal has a major influence upon the detection of movement. A frame-memory 131, a high frequency brightness signal extrac-ting circuit 132, a subtractor 133, a fil-ter 13~ and a movement decision circuit 135 have -the sarne function as the frame memory 119, the high frequency brightness signal extracting circuit 120, the subtractor 121, the filter 123 and the movement decision circuit 127, respectively, and operate in a similar manner correspondingly.
In other words, this is corresponds to the case where the coefficient of the multiplier 125 is set zero in Fig. 14.
Fig. 16 shows another example of the high frequency brightness signal extracting circuit 132 in Fig. 15.
In Fig. 16, in order to simply obtain a high frequency Y signal without using a line memory, there is employed a filter 156 for blocking the signals in the vicinity of zero frequency and the subcarrier frequency. The filter 156 comprises delay circuit 137, 139 and 1~0 each for one sampling period delay, a subtractor 133 and an adder 1~1. The high frequency Y signal delivered from the filter 156 is fed to an absolu-te circuit 142 to take -the absolute value thereof. The absolute value is Eed to a delay circuit 143 having one sampling period delay and an adder 144. The adder adds the absolute values from the delay circuit 143 and the absolute circuit 1~2.
Further, an average value lS delivered from a multlplier 162 having a coefficient of 1/2.
Fig. 17 is a block diagram of a nineth embodiment of the present invention. This embodiment is provided for detecting the movement a monochromatic television signal. A monochroma-tic television signal from an input terminal 145 is supplied to a frame memory 146, and a sub-tractor 147. The subtractor 147 produces a frame difference signal. The frame difference signal is supplied through a delay circuit 157 to a movement decision circuit 154. In a high frequency brightness signal extracting circuit 148, delay circuits 149 and 151 each having one sampling period delay, subtractors 150 and 152 and a multiplier 158 having coefficient of 1/4 compose a filter having a transmission function H(z) represented by z-conversion as follows:
I~(z) = 1/4 (_z-2 + 2z-1 - 1) The high frequency Y signal delivered from the multiplier 158 is fed to an absolute circuit 153. The absolute value 20 from the circuit 153 is fed to a delay circuit 159 and, adder 160, and,then, a multiplier 161 having coefficient of 1/2 produces an average value. This average value is supplied to the movement decision circuit 154. The movement decision circuit 154 has the same function as 25 the movement decision circui-t 104 in Fig. 11, so that i-t outputs a signal indicating the degree of movemen-t to an ~utput terminal 155.
In Fig. 11, -the chrominance signal polarity inverting circuit 101 may be replaced by the frame memory 100, in their positions in Fig. 11, thus making it possible for a line memory necessary for the high frequency brightness signal extracting circuit 102 to be used commonly. As an alternative, a high frequency Y signal for ~he moving detection may be extracted from the signal delivered from the frame memory. In Figs. 11 and 1~, when there is a delay difference between the frame difference signal and the high frequency Y signal, a proper delay circuit should be inserted into either signal line. When the high frequency Y signal is used for the moving detection, it is alternatively possible to use its power value or it level average value of previous and subsequent several samples.
In the embodiments of Figs. 11 and 14, the movement detection signal obtained at each of the output terminals 105 and 129 has zero in the standstill image area and has a certain amplitude in the moving image area. To classify the image into several steps from stillness to full movement in accordance with the degree of movement, the amplitude of the movement detection signal is compared with several proper threshold values for determining one of the steps.
While the function y = f(x) shown in Flg. 13(a) was linear, a non-linear characteristic may be also used such ~5~
-that the frame difference signal less than a certain value is regarded as noise and the movement detection signal of zero is delivered in this region as shown in Fig. 18.
In the embodiment of Pig. 14, the frame difference signal is obtained by adding the Y frame difference and the C frame difference. On this occasion, it is not necessarily required to coincide weighting factors of the two frame differences. In fact, the C frame difference is apt to be larger than the Y frame difference even when the brightness (Y) and chrominance (C) signals contain the same movement because a cross talk of the high frequency Y signal, a jitter, etc. are con-tained in the television signal. Therefore, it is preferred to make the weighting factor of the C difference smaller, for example, less than "1".
While the conversion circuit 128 was composed of the adder 126 and the movement decision circuit 127 in the embodi~ent of Fig. 14, it can be also realized by using a read only memory (ROM). Furthermore, three types of input/output characteris-tics of f5(x), f6(x) and f7(x) as shown in Fig. 19 are prepared, and one characteristic is selected in accordance with the magnitude of high frequency Y signal.
As fully described in -the above, -the present invention permits correct detection of movement for - 28 - ~ ~5~
a monochromatic signal and a color television signal including the edge portion. Therefore, the present invention can be applied to various video signal processing circuits, such as an adaptive Y/C separator and scanning sequence converter, which utilize movement information of images.
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A movement detection apparatus for detecting the degree of movement of an image which is represented by a compo-site television signal having a brightness signal component and a chrominance signal component, said apparatus comprising: means for producing a first frame difference signal having a magnitude which is related to the difference between a present and previous brightness television signal, said frame difference means operat-ing independently of the direction of movement of picture elements of said image; means for producing a second frame difference sig-nal having a magnitude which is related to the difference between a present and previous chrominance signal, said frame difference producing means operating independently of the direction of move-ment of picture elements of said image; means for producing a first sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on said bright-ness signal component of said television signal, said first sum of picture element differences means operating independently of the direction of movement of picture elements of said image; means for producing a second sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on the chrominance signal on said chrominance signal compon-ent of said television signal, said second sum of picture element differences means operating independently of the direction of movement of picture elements of said image; and means for produc-ing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.
2. The apparatus of claim 1, further comprising a multi-plier for scaling said second frame difference signal and an addition circuit for combining said first frame difference signal and said second frame difference signal scaled by said multiplier.
3. The apparatus of claim 2, further comprising a smoothing circuit for smoothing said output which is indicative of the degree of movement of said image.
4. The apparatus as in claim 1, wherein said composite television signal comprises a digitized television signal.
5. A movement detection apparatus for detecting the degree of movement of an image which is represented by a television sig-nal, said apparatus comprising: means for producing a frame dif-ference signal having a magnitude which is related to the dif-ference between a present and a previous television signal, said frame difference means operating independently of the direction of movement of picture elements of said image; means for producing a sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements, said picture ele-ment differences means operating independently of the direction of movement of picture elements of said image; and means for producing an output which is indicative of the degree of movement of said image in response to said frame difference signal and said picture element differences signal; said means for producing a frame difference signal including a frame memory for storing therein previous frame data of said television signal and subtrac-tor means for calculating a difference between said television signal and said previous frame data; said picture element dif-ferences means comprising first means responsive to said television signal for producing a present frame sum of picture element dif-ferences signal, second means responsive to said previous frame data for producing a previous frame sum of picture element dif-ferences signal and a first addition circuit for adding said present and previous picture element differences signal, each said first and second means comprising: an input; a first subtrac-tion circuit and a first line memory connected to said input, said line memory having an output connected to said first subtrac-tion circuit, said first subtraction circuit having an output for calculating a difference between signals from said input and said first line memory; a first absolute value circuit for generating an absolute value of said output of said first subtraction cir-cuit; a second line memory and a first addition circuit having respective inputs for receiving said absolute value, said second line memory having an output connected to another input of said first addition circuit, said first addition circuit having an output representing a difference between said inputs of said first addition circuit; a delay circuit for delaying said output of said first addition circuit, said delayed output constituting said sum of picture element differences signal; a first one sample delay and a second subtraction circuit having a respective first input connected to said first line memory, said second subtrac-tion circuit having a second input connected to said first one sample delay and an output representing the difference between said first and second inputs of said second subtraction circuit;
a second absolute value circuit connected to said output of said second subtraction circuit; and a second one sample delay and a second addition circuit having respective first inputs connected to said second absolute value circuit, said second one sample delay being further connected to a second input of said second addition circuit, said second addition circuit having an output, said output of said second addition circuit being effective for enabling calculation of said previous frame sum of picture element differences signal.
a second absolute value circuit connected to said output of said second subtraction circuit; and a second one sample delay and a second addition circuit having respective first inputs connected to said second absolute value circuit, said second one sample delay being further connected to a second input of said second addition circuit, said second addition circuit having an output, said output of said second addition circuit being effective for enabling calculation of said previous frame sum of picture element differences signal.
6. A movement detection apparatus for detecting the degree of movement of an image which is represented by a composite tele-vision signal having a brightness signal component and a chromin-ance signal component, said apparatus comprising: means for pro-ducing a frame difference signal having an output which is related to the difference between a present and a previous television signal, said frame difference means operating independently of the direction of movement of picture elements of said image;
first means for filtering from said output of said frame differ-ence signal said chrominance signal component to produce a filter-ed frame difference signal; means for producing a sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements, said picture element differences means operating independently of the direction of movement of picture elements of said image; second means for filtering from said picture element differences signal said chrominance signal compon-ent to produce a picture filtered element differences signal; and means for producing an output indicative of the degree of movement of said image in response to said filtered frame difference signal and said filtered picture element differences signal; said picture element differences means comprising a 2-line type comb filter which includes first and second series connected line memories;
first, second and third multipliers respectively connected to said television signal, said first line memory and said second line memory; a first addition circuit for adding the outputs of said first, second and third multipliers; said frame difference signal producing means comprising a frame memory for storing therein pre-vious frame data of said television signal and subtractor means for calculating a difference between said television signal and said previous frame data; an absolute value circuit connected to said first filtering means, and a delay circuit connected to said absolute value circuit, said delay circuit being connected to said means for producing an output indicative of the degree of move-ment of said image; said picture element differences signal pro-ducing means further comprising a first one sample delay circuit connected to said comb filter; a first subtraction circuit con-nected to said first one sample delay circuit and said comb filter;
an absolute value circuit connected to said first subtraction cir-cuit; a second one sample delay circuit connected to said absolute value circuit; a second addition circuit connected to said second one sample delay circuit and to said absolute value circuit; a second subtraction circuit connected to said television signal and to said first line memory; a third subtraction circuit connected to said first line memory and to said second line memory; a respec-tive filtering means connected to each said second and third sub-traction circuits; a third addition circuit connected to said respective filtering means; and a fourth addition circuit connec-ted to said third addition circuit and to said second addition circuit, said fourth addition circuit being coupled to said means for producing an output indicative of the degree of movement of said image.
first means for filtering from said output of said frame differ-ence signal said chrominance signal component to produce a filter-ed frame difference signal; means for producing a sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements, said picture element differences means operating independently of the direction of movement of picture elements of said image; second means for filtering from said picture element differences signal said chrominance signal compon-ent to produce a picture filtered element differences signal; and means for producing an output indicative of the degree of movement of said image in response to said filtered frame difference signal and said filtered picture element differences signal; said picture element differences means comprising a 2-line type comb filter which includes first and second series connected line memories;
first, second and third multipliers respectively connected to said television signal, said first line memory and said second line memory; a first addition circuit for adding the outputs of said first, second and third multipliers; said frame difference signal producing means comprising a frame memory for storing therein pre-vious frame data of said television signal and subtractor means for calculating a difference between said television signal and said previous frame data; an absolute value circuit connected to said first filtering means, and a delay circuit connected to said absolute value circuit, said delay circuit being connected to said means for producing an output indicative of the degree of move-ment of said image; said picture element differences signal pro-ducing means further comprising a first one sample delay circuit connected to said comb filter; a first subtraction circuit con-nected to said first one sample delay circuit and said comb filter;
an absolute value circuit connected to said first subtraction cir-cuit; a second one sample delay circuit connected to said absolute value circuit; a second addition circuit connected to said second one sample delay circuit and to said absolute value circuit; a second subtraction circuit connected to said television signal and to said first line memory; a third subtraction circuit connected to said first line memory and to said second line memory; a respec-tive filtering means connected to each said second and third sub-traction circuits; a third addition circuit connected to said respective filtering means; and a fourth addition circuit connec-ted to said third addition circuit and to said second addition circuit, said fourth addition circuit being coupled to said means for producing an output indicative of the degree of movement of said image.
7. A movement detection apparatus for detecting the degree of movement of an image which is represented by a composite tele-vision signal having a brightness signal component and a chromin-ance signal component, said apparatus comprising: means for pro-ducing a first frame difference signal having a magnitude which is related to the difference between a present and previous brightness television signal, said frame difference means operating indepen-dently of the direction of movement of picture elements of said image; means for producing a second frame difference signal having a magnitude which is related to the difference between a present and a previous chrominance signal, said frame difference producing means operating independently of the direction of movement of picture elements of said image; means for producing a first sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on a present frame, said first sum of picture element differences means operating independently of the direction of movement of picture elements of said image; means for producing a second sum of picture element differences signal having a magnitude which is related to the differences between the value of a given picture element and adjacent picture elements based on a previous frame, said second sum of picture element differences means operating independently of the direction of movement of picture elements of said image;
and means for producing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.
and means for producing an output which is indicative of the degree of movement of said image in response to said first and second frame difference signals and said first and second picture element differences signals.
8. The apparatus of claim 7, further comprising a multi-plier for scaling said second frame difference signal and an addition circuit for combining said first frame difference signal and said second frame difference signal scaled by said multiplier.
9. The apparatus of claim 8, further comprising a smooth-ing circuit for smoothing said output which is indicative of the degree of movement of said image.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000576717A CA1257690A (en) | 1983-09-08 | 1988-09-07 | Apparatus for detecting movement in a television signal |
Applications Claiming Priority (6)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP165447/1983 | 1983-09-08 | ||
| JP58165447A JPS6057793A (en) | 1983-09-08 | 1983-09-08 | Movement detection circuit |
| JP58214541A JPS60106288A (en) | 1983-11-15 | 1983-11-15 | Movement detecting circuit |
| JP214541/1983 | 1983-11-15 | ||
| CA000462642A CA1246734A (en) | 1983-09-08 | 1984-09-07 | Apparatus for detecting movement in a television signal |
| CA000576717A CA1257690A (en) | 1983-09-08 | 1988-09-07 | Apparatus for detecting movement in a television signal |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000462642A Division CA1246734A (en) | 1983-09-08 | 1984-09-07 | Apparatus for detecting movement in a television signal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1257690A true CA1257690A (en) | 1989-07-18 |
Family
ID=27167463
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000576717A Expired CA1257690A (en) | 1983-09-08 | 1988-09-07 | Apparatus for detecting movement in a television signal |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1257690A (en) |
-
1988
- 1988-09-07 CA CA000576717A patent/CA1257690A/en not_active Expired
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