JP2009055171A - Motion detection circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect motion of a color signal even if the color signal largely moves in one frame and the signal two frames after returns to the same position of the initial frame. <P>SOLUTION: A color difference detection means (12) for detecting a difference signal of the color signal comprises: a horizontal BPF (1211) receiving input image data (Va0) as input; a horizontal BPF (1212) receiving delay image data (Vb0) as input; a color difference extraction means (121) for inverting the phase of output of one horizontal BPF (1215) and subtracting the inverted phase from output of the other BPF; and a sensitivity conversion means (122) comprising an absolute value calculation means (1221), a prefilter (1222) and a ROM 1223, thereby the color difference detection means (12) detects the motion of the color signal even if, for example, the color signal largely moves in one frame and the signal two frames after returns to the same position of the initial frame. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motion detection circuit used in a motion adaptive three-dimensional Y / C separation circuit.

  For example, in a conventional motion detection circuit used in an NTSC three-dimensional Y / C separation circuit, a luminance difference is obtained from a difference between a video signal of the current frame and a video signal of one frame before, and the video signal of the current frame is obtained. The difference between the luminance and the color is obtained from the difference between the image signal and the video signal two frames before, and the motion detection signal is synthesized based on these difference signals. As an example, in the motion detection circuit described in Patent Document 1 below, the difference between the video signal of the current frame and the video signal two frames before is detected as a motion amount, and the video signal of the current frame and the two frame periods are detected. When there is an edge signal correlation with the previous video signal, the amount of motion between the two frames is controlled based on the level of the edge signal of the video signal of the current frame, and the controlled amount of motion is determined between the two frames. As the amount of motion, the larger of the amount of motion between the two frames and the amount of motion obtained from the difference between the video signal and the video signal of one frame before is output as the amount of motion. In the motion detection circuit described in Patent Document 2 below, the first motion amount detection that detects the amount of motion of the low frequency component from the difference between the video signal of the current frame and the video signal of one frame before. And a second motion amount detector for detecting a motion amount between two frames from the difference between the video signal of the current frame and the video signal of the previous two frames, and detected by the first motion amount detector The larger one of the motion amount detected and the motion amount detected by the second motion amount detector is output. In the second motion amount detector, the difference between the two frames is delayed for the period of the two sampling pulses, and the difference between the two frames and the signal delayed by the period of the two sampling pulses are Select and output every cycle.

Japanese Unexamined Patent Publication No. 7-322285 (0007-0021, FIG. 1) JP 7-298290 A (0007 to 0019, FIG. 1)

  As described above, the motion detection method for obtaining the luminance difference from the one-frame difference and obtaining the luminance and color difference from the two-frame difference mainly has the property that the color phase of the NTSC television signal is the same in two frames. On the other hand, although it is a proper method, since a time difference of 2 frames is required to detect a color difference, the 1-frame time difference signal of the color signal cannot be detected, and the color signal moves greatly in 1 frame, and 2 frames later In the case of returning to the same position as two frames before, there is a problem that the motion cannot be detected and the image is broken.

  Although the NTSC system has been described above, other systems such as the PAL system have similar problems. That is, in the case of the PAL system, the color signal 2 frame time difference signal cannot be detected, and if the color signal moves greatly in 2 frames and returns to the same position as 4 frames before after 4 frames, the motion cannot be detected. There's a problem.

  An object of the present invention is to detect a time difference signal of a color signal α frame (α = 1 in the case of NTSC system, α = 2 in the case of PAL system) in a motion detection circuit of a three-dimensional Y / C separation circuit. Is to be able to do it.

The motion detection circuit of the present invention includes:
An input video signal, a first delayed signal obtained by delaying the input video signal by a predetermined number of frame periods, and a second delayed signal obtained by delaying the predetermined number of frames by twice a frame period;
Luminance difference detection means for detecting a difference in luminance signal from the input video signal and the first delay signal;
Color difference detection means for detecting a difference in color signal from the input video signal and the first delay signal;
Color luminance difference detection means for detecting a difference between a luminance signal and a color signal from the input video signal and the second delay signal;
Combining means for combining the output of the luminance difference detecting means, the output of the color difference detecting means, and the output of the color luminance difference detecting means;
Edge detection means for determining the presence or absence of an edge in the image from the input video signal and the first delay signal;
Stillness determination means for determining whether a luminance signal is stationary between frames from the input video signal, the first delay signal, and the second delay signal,
The detection sensitivity in the luminance difference detection means is adjusted according to the determination result by the edge determination means,
The detection sensitivity in the color difference detection unit is adjusted according to the determination result by the edge determination unit and the determination result by the stationary determination unit,
The color luminance difference detection means selects whether to adjust the detection sensitivity according to the determination result by the edge determination means and the determination result by the stillness determination means, or to set a predetermined color luminance difference detection inclination setting value. Is possible.

  According to the present invention, in a motion detection circuit of a three-dimensional Y / C separation circuit, a time difference signal of an α frame (α = 1 in the case of the NTSC system, α = 2 in the case of the PAL system) is detected. can do.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a motion detection circuit according to Embodiment 1 of the present invention. The motion detection circuit 1 includes an input video signal, for example, a composite color television signal (input image data) Va0 and an input image data in an α frame period (α = 1 in the NTSC system, and α = 2 in the PAL system. ) The delayed first delayed signal (first delayed image data) Vb0 and the first delayed image data Vb0 are delayed by an α frame period, that is, the input image data is delayed by a 2α frame period. 2 delay image data) Vc0, the luminance difference detecting means 11, the color difference detecting means 12, the color luminance difference detecting means 13, the maximum value circuit 16, the spatiotemporal expanding means 17, Edge detection means 14 and stillness determination means 15 are provided.

The luminance difference detection unit 11 detects a difference in luminance signal from the input image data Va0 and the first delayed image data Vb0, and outputs a luminance difference signal DFy representing the difference.
The color difference detection unit 12 detects a color signal difference from the input image data Va0 and the first delay image data Vb0, and outputs a color difference signal DFc representing the difference.
The color luminance difference detecting means 13 detects the difference between the luminance signal and the color signal from the input image data Va0 and the second delayed image data Vc0, and outputs a color luminance difference signal DFyc representing the difference.
The maximum value circuit 16 receives the luminance difference signal DFy, the color difference signal DFc, and the color luminance difference signal DFyc, and outputs these maximum values.
The spatiotemporal expansion means 17 expands the difference signal output from the maximum value circuit 16 in the time direction and the spatial direction, and outputs a motion signal MVS.

The edge detection means 14 determines the presence or absence of an edge in the image from the input image data Va0 and the first delay image data Vb0.
The stillness determination means 15 determines whether or not the luminance signal is stationary between frames from the input image data Va0, the first delay image data Vb0, and the second delay image data Vc0.
The detection sensitivity in the luminance difference detection means 11 is adjusted according to the determination result by the edge determination result 14.
The detection sensitivity in the color difference detection unit 12 and the color luminance difference detection unit 13 is adjusted according to the determination result by the edge determination unit 14 and the determination result by the stillness determination unit 15.

FIG. 2 shows an example of the luminance difference detection means 11 shown in FIG.
The illustrated luminance difference detecting unit 11 includes a luminance difference extracting unit 111, a sensitivity converting unit 112, an isolated point removing unit 113, and an inclination setting unit 114.

  The luminance difference extraction unit 111 includes a horizontal low-pass filter (horizontal LPF) 1111 that extracts a low-frequency component of the input image data Va0, and a horizontal low-pass filter that extracts a low-frequency component of the first delayed image data Vb0 ( Horizontal LPF) 1112 and a subtracting circuit 1113 for subtracting the output of the horizontal LPF 1112 from the output of the horizontal LPF 1111.

The sensitivity conversion unit 112 includes an absolute value circuit 1121, a prefilter 1122, and a ROM (Read Only Memory) 1123.
The absolute value conversion circuit 1121 converts the output signal of the luminance difference extraction unit 111 into an absolute value, and outputs an absolute value conversion luminance difference signal ADy.
The pre-filter 1122 removes a high frequency noise component present in the absolute valued luminance difference signal ADy, and outputs a filtered absolute valued luminance difference signal FADy.

  The ROM 1123 performs sensitivity conversion on the output signal FADy of the pre-filter 1122 in accordance with the sensitivity intercept setting signal SXy and the inclination setting signal SGy.

  FIG. 3 shows an example of the pre-filter 1122. As described above, the pre-filter 1122 removes the high frequency noise component present in the absolute difference luminance difference signal. However, any of a plurality of operation modes can be selected, and the high frequency noise component can be selected. It is also possible to operate in a mode that outputs the input as it is without removing it.

  The illustrated prefilter 1122 includes a first delay unit 2221, a second delay unit 2222, a low-pass filter (horizontal LPF) 2223, an intermediate value circuit 2224, a maximum value circuit 2225, and a selection unit 2226. With.

  The first delay means 2221 delays the signal (absolute value difference data) ADy from the absolute value circuit 1121 by one pixel period, and the second delay means 2222 delays the output of the first delay means 2221 by one pixel period. To do.

The horizontal LPF 2223 receives the signal (absolute difference data) ADy from the absolute value circuit 1121, the output of the first delay means 2221, and the output of the second delay means 2222 as inputs, and the low range of the absolute value difference data. Output the component.
The intermediate value circuit 2224 receives three signals, that is, the signal (absolute value difference data) ADy from the absolute value circuit 1121, the output of the first delay means 2221, and the output of the second delay means 2222, and inputs the above three inputs. Output the intermediate value of the signal.
The maximum value circuit 2225 receives three signals, the signal from the absolute value circuit 1121 (absolute value difference data) ADy, the output of the first delay means 2221, and the output of the second delay means 2222, and the above three inputs. Output the maximum value of the signal.

  The selection means 2226 receives the output of the first delay means 2221, the output of the horizontal LPF 2223, the output of the intermediate value circuit 2224, and the output of the maximum value circuit 2225, and according to the value of the prefilter selection signal SPFy. Select either one and output.

  For example, the prefilter selection signal SPFy can take one of four values “00”, “01”, “10”, “11”, and when it is “00”, the output of the first delay means 2221. When “01”, the output of the horizontal LPF 2223 is selected. When “10”, the output of the intermediate value circuit 2224 is selected. When “11”, the output of the maximum value circuit 2225 is selected. The selected signal is output as the output signal FADy of the pre-filter 1122. The value of the prefilter selection signal SPFy is set in advance or prepared separately according to the user's preference, for example.

The ROM 1123 has the input / output characteristics shown in FIG. 4, for example. The input / output characteristics shown in FIG. 4 are defined by the sensitivity intercept Xsy and the sensitivity gradient Gry.
The sensitivity intercept Xsy is set by, for example, a sensitivity intercept setting signal SXy set in advance or separately, and the sensitivity gradient Gry is set by, for example, an inclination setting signal SGy supplied from the gradient setting means 114.

  In accordance with the edge signal EDG output from the edge detection unit 14, the gradient setting unit 114 has a gradient setting signal so that the greater the detected edge level, the smaller the sensitivity gradient Gry. SGy is adjusted. This is because, in general, an edge portion is likely to be erroneously detected as a motion signal. Therefore, when an edge is detected (as the level of the edge is larger), the sensitivity of difference detection is adjusted to decrease.

The illustrated tilt setting unit 114 includes a selection unit 1141. The selection unit 1141 selects any one of the first to fourth inclination setting signals SGy0 to SGy3 that are set in advance or are prepared separately, and supplies the selected inclination setting signals SGy to the ROM 1123.
The sensitivity gradients Gry0 to Gry3 specified by the first to fourth gradient setting signals SGy0 to SGy3 are different from each other, for example, Gry0 <Gry1 <Gry2 <Gry3.
Have the relationship.
For example, the gradient setting signals SGy0 to SGy3 are selected so that the sensitivity gradient Gry becomes a smaller value as the edge level indicated by the edge signal EDG is larger.

  In FIG. 4, the input / output characteristics are represented by continuous straight lines. For example, when the input signal to the ROM 1123 is 8 bits, the value of 0 to 255 is used, and when the input signal is 10 bits, the value of 0 to 1023 is set. , Converted into output signals 0-8.

  The isolated point removing unit 113 compares the value of the input (output of the sensitivity conversion unit 112) for each pixel with the value of the input for the surrounding pixels of the pixel, and inputs the input for each pixel (current pixel). When the value is isolated unlike the input value for the surrounding pixels, the input value for each pixel is changed to match the input value for the surrounding pixels and output. For example, when only the central pixel is larger than the previous and subsequent four pixels, for example, when only the central pixel has a size more than twice that of the others, the central pixel is halved and only the central pixel is In the case of being small, for example, when only the center pixel has a size of 1/2 or less as compared with others, the center pixel is doubled. The isolated point removing unit 113 may be omitted, and the output of the sensitivity converting unit 112 may be used as the output of the luminance difference detecting unit 11 as it is.

FIG. 5 shows an example of the color difference detection means 12 shown in FIG.
The illustrated color difference detection unit 12 includes a color difference extraction unit 121, a sensitivity conversion unit 122, a horizontal enlargement unit 123, and an inclination setting unit 124.

  The luminance difference extraction unit 121 includes a horizontal bandpass filter (horizontal BPF) 1211 that extracts a band component of the input image data Va0 and a horizontal bandpass filter (horizontal BPF) 1212 that extracts a band component of the first delay image data Vb0. And an inversion circuit 1215 that inverts the sign of the output of the horizontal BPF 1212, and a subtraction circuit 1213 that subtracts the output of the inversion circuit 1215 from the output of the horizontal BPF 1211.

The sensitivity conversion unit 122 includes an absolute value circuit 1221, a pre-filter 1222, and a ROM 1223.
The absolute value conversion circuit 1221 converts the output signal of the color difference extraction unit 121 into an absolute value and outputs an absolute value color difference signal ADc.
The prefilter 1222 removes a high frequency noise component present in the absolute valued color difference signal ADc, and outputs a filtered absolute valued color difference signal FADc.

  The ROM 1223 performs sensitivity conversion on the output signal FADc of the pre-filter 1222 according to the sensitivity intercept setting signal SXc and the inclination setting signal SGc.

  The prefilter 1222 is configured in the same manner as the prefilter 1122 shown in FIG. However, the output ADc of the absolute value circuit 1221 is supplied instead of the output ADy of the absolute value circuit 1121, and the prefilter selection signal SPFc for the prefilter 1222 is used instead of the prefilter selection signal SPFy. Supplied.

  The ROM 1223 is configured in the same manner as the ROM 1123 in FIG. 2, and its input / output characteristics are the same as those shown in FIG. However, input / output characteristics are defined by the sensitivity intercept Xsc and the sensitivity gradient Grc instead of the sensitivity intercept Xsy and the sensitivity gradient Gry. For these settings, the sensitivity intercept setting is set instead of the sensitivity intercept setting signal SXy and the gradient setting signal SGy. A signal SXc and an inclination setting signal SGc are supplied. The sensitivity intercept setting signal SXc is set in advance or prepared separately, for example, and the inclination setting signal SGc is supplied from the inclination setting means 124, for example.

The inclination setting means 124 outputs an inclination setting signal SGc according to the interframe still luminance signal STL output from the stillness determination circuit 15 and the edge signal EDG output from the edge detection means 14.
For example, when the inter-frame still luminance signal STL takes a value (for example, “1”) indicating that the luminance signal is stationary between frames, an inclination setting signal SGc designating inclination Grc = zero is output (this) Thus, the output of the color difference detecting means 12 becomes 0). When the interframe still luminance signal STL takes a value (for example, “0”) indicating that the luminance signal is not stationary between frames, the sensitivity gradient increases as the edge level indicated by the edge signal EDG increases. The inclination setting signal SGc is adjusted so that Grc becomes a smaller value. This is because, like the inclination setting unit 114 of the luminance difference detection unit 11, generally, an edge portion is likely to be erroneously detected as a motion signal. Therefore, when an edge is detected, the higher the level of the edge is, In other words, the adjustment is made to reduce the sensitivity of difference detection.

The illustrated tilt setting unit 124 includes a selection unit 1241, a set value storage unit 1242, and a selection unit 1243.
The selection unit 1241 selects any one of first to fourth inclination setting signals SGc0 to SGc3 that are set in advance or are prepared separately, and outputs the selected inclination setting signal SGce.
One of the first to fourth inclination setting signals SGc0 to SGc3, for example, the first inclination setting signal SGc0 specifies zero inclination. Further, the sensitivity gradients Grc0 to Grc3 specified by the first to fourth gradient setting signals SGc0 to SGc3 are different from each other, for example, Grc0 <Grc1 <Grc2 <Grc3.
Have the relationship.
For example, the gradient setting signals SGc0 to SGc3 are selected so that the sensitivity gradient Grc becomes a smaller value as the edge level indicated by the edge signal EDG is larger.

The setting value storage unit 1242 stores a predetermined inclination setting value (color difference detection inclination setting value) SGc4. The inclination setting value SGc4 is set in advance or separately prepared. For example, the user can input or change the setting value SGc4.
The selection unit 1243 outputs the output SGce of the selection unit 1241 and the fifth gradient setting signal SGc4 indicating the gradient setting value SGc4 stored in the setting value storage unit 1242 (represented by the same sign as the gradient setting value itself for convenience). As an input, any one is selected according to the value of the inclination selection signal SSGc and supplied to the ROM 1223 as the selected inclination setting signal SGc.
The sensitivity gradient Grc4 specified by the fifth gradient setting signal SGc4 is desirably larger than the sensitivity gradients Grc0 to Grc3 specified by the first to fourth gradient setting signals SGc0 to SGc3. in this case,
Grc4>Grc3>Grc2>Grc1> Grc0
There is a relationship.
The value of the inclination selection signal SSGc is stored in a register (not shown), for example, and is set in advance or prepared separately according to the user's preference, for example.

When the interframe still luminance signal STL takes a value (for example, “1”) indicating that the luminance signal is stationary between frames, the selection unit 1241 uses the first inclination setting signal that specifies the inclination Grc = zero. SGc0 is selected.
When the interframe still luminance signal STL takes a value (for example, “0”) indicating that the luminance signal is not stationary between frames, the sensitivity gradient increases as the edge level indicated by the edge signal EDG increases. The selection of the slope setting signals SGc0 to SGc3 is performed by the selection unit 1241 so that Grc becomes a smaller value.

  The horizontal enlargement unit 123 enlarges the motion signal output from the sensitivity conversion unit 122 in the horizontal direction. The horizontal enlargement unit 123 may be omitted, and the output of the sensitivity conversion unit 122 may be used as the output of the color difference detection unit 12 as it is.

FIG. 6 shows an example of the color luminance difference detection means 13 shown in FIG.
The illustrated color luminance difference detection unit 13 includes a color difference extraction unit 131, a sensitivity conversion unit 132, a horizontal enlargement unit 133, and an inclination setting unit 134.

  The color luminance difference extraction unit 131 includes a subtraction circuit 1313 that subtracts the second delayed image data Vc0 from the input image data Va0.

The sensitivity conversion unit 132 includes an absolute value circuit 1321, a prefilter 1322, and a ROM 1323.
The absolute value conversion circuit 1321 converts the output signal of the luminance difference extraction unit 131 into an absolute value and outputs an absolute value color luminance difference signal ADyc.
The pre-filter 1322 removes high frequency noise components present in the absolute valued color luminance difference signal ADyc and outputs a filtered absolute value color luminance difference signal FADyc.

  The ROM 1323 performs sensitivity conversion on the output signal FADyc of the pre-filter 1322 according to the sensitivity intercept setting signal SXyc and the inclination setting signal SGyc.

  The prefilter 1322 is configured similarly to the prefilter 1122 shown in FIG. However, instead of the output ADy of the absolute value circuit 1121, the output ADyc of the absolute value circuit 1321 is supplied, and instead of the prefilter selection signal SPFy, the prefilter selection signal SPFyc ( (Not shown) is supplied.

  The ROM 1323 is configured in the same manner as the ROM 1123 in FIG. 2, and its input / output characteristics are the same as those shown in FIG. However, the input / output characteristics are defined by the sensitivity intercept Xsyc and the sensitivity gradient Gryc instead of the sensitivity intercept Xsy and the sensitivity gradient Gry. For these settings, the sensitivity intercept setting is set instead of the sensitivity intercept setting signal SXy and the gradient setting signal SGy. A signal SXyc and an inclination setting signal SGyc are supplied. The sensitivity intercept setting signal SXyc is set in advance or prepared separately, for example, and the inclination setting signal SGyc is supplied from the inclination setting means 134, for example.

The inclination setting means 134 outputs an inclination setting signal SGyc in accordance with the interframe still luminance signal STL output from the stillness determination circuit 15 and the edge signal EDG output from the edge detection means 14.
For example, when the interframe still luminance signal STL takes a value (for example, “1”) indicating that the luminance signal is stationary between frames, an inclination setting signal SGyc designating inclination Gryc = zero is output (this) Therefore, the output of the color luminance difference detecting means 13 becomes 0). When the interframe still luminance signal STL takes a value (for example, “0”) indicating that the luminance signal is not stationary between frames, the sensitivity gradient increases as the edge level indicated by the edge signal EDG increases. The inclination setting signal SGyc is adjusted so that Gryc becomes a smaller value. This is because, like the inclination setting unit 114 of the luminance difference detection unit 11, generally, an edge portion is likely to be erroneously detected as a motion signal. Therefore, when an edge is detected, the higher the level of the edge is, In other words, the adjustment is made to reduce the sensitivity of difference detection.

The illustrated tilt setting unit 134 includes a selection unit 1341, a set value storage unit 1342, and a selection unit 1343.
The selection unit 1341 selects any one of first to fourth inclination setting signals SGyc0 to SGyc3 that are set in advance or are prepared separately, and outputs the inclination setting signal SGyce.
One of the first to fourth inclination setting signals SGyc0 to SGyc3, for example, the first inclination setting signal SGyc0 specifies zero inclination. Further, the gradients Gryc0 to Gyc3 specified by the first to fourth gradient setting signals SGyc0 to SGyc3 are different from each other, for example, Gryc0 <Gryc1 <Gryc2 <Gryc3.
Have the relationship.
For example, the gradient setting signals SGyc0 to SGyc3 are selected so that the sensitivity gradient Gryc becomes a smaller value as the edge level indicated by the edge signal EDG is larger.

The setting value storage unit 1342 stores a predetermined inclination setting value (color luminance difference detection inclination setting value) SGyc4. The inclination setting value SGyc4 is set in advance or separately prepared. For example, the user can input or change the setting value SGyc4.
The selection unit 1343 outputs the output SGyce of the selection unit 1341 and a fifth gradient setting signal SGyc4 (represented by the same sign as the gradient setting value itself for convenience) representing the gradient setting value SGyc4 stored in the setting value storage unit 1342. As an input, any one is selected according to the value of the inclination selection signal SSGyc and supplied to the ROM 1323 as the selected inclination setting signal SGyc.
The sensitivity gradient Gryc4 specified by the fifth gradient setting signal SGyc4 is desirably a value larger than the sensitivity gradients Gryc0 to Gryc3 specified by the first to fourth gradient setting signals SGyc0 to SGyc3. in this case,
Gryc4>Gryc3>Gryc2>Gryc1> Gryc0
There is a relationship.
The value of the inclination selection signal SSGyc is stored in a register (not shown), for example, and is set in advance or prepared separately according to the user's preference, for example.

When the inter-frame still luminance signal STL takes a value (for example, “1”) indicating that the luminance signal is stationary between frames, the selection unit 1341 uses the first inclination setting signal that specifies the inclination Gryc = zero. Select SGyc0.
When the interframe still luminance signal STL takes a value (for example, “0”) indicating that the luminance signal is not stationary between frames, the sensitivity gradient increases as the edge level indicated by the edge signal EDG increases. The inclination setting signals SGyc0 to SGyc3 are selected by the selection unit 1341 so that Gryc becomes a smaller value.

  The horizontal enlargement unit 133 enlarges the motion signal output from the sensitivity conversion unit 132 in the horizontal direction. The horizontal enlargement unit 133 may be omitted, and the output of the sensitivity conversion unit 132 may be used as the output of the color luminance difference detection unit 13 as it is.

FIG. 7 shows an example of the edge detection means 14 shown in FIG. The input image data Va0 and the second delayed image data Vc0 are input to the edge detection means 14 shown in the figure, and edge data in these is extracted.
The illustrated edge detection means 14 includes first to fourth line delay means 140a, 140b, 140c, 140d, first and second vertical LPFs 141a, 141b, and first to sixth horizontal LPFs 143a, 143b, 143c. , 143d, 143e, 143f, first to fourth delay means 142a, 142b, 142c, 142d, first and second horizontal difference calculation units 144a, 144c, and first and second vertical difference calculation units. 144b, 144d, first to fourth ROMs 145a, 145b, 145c, 145d, first and second horizontal enlargement means 146a, 146b, and edge composition means 147.

The input image data Va0 is delayed by predetermined lines (for example, one line in the NTSC system and two lines in the PAL system) by the first and second line delay units 140a and 140b, respectively.
The vertical LPF 141a receives the input image data Va0, the output of the first line delay unit 140a and the output of the second line delay unit 140b as input, and performs filtering in the vertical direction to extract a low frequency component, that is, a luminance component.

  The output FVa00 of the vertical LPF 141a is delayed by a predetermined number (for example, one) of pixels by the first delay unit 142a, and further delayed by a predetermined number (for example, one) of pixels by the second delay unit 142b. The output FVa00 of the vertical LPF 141a, the output FVa01 of the first delay unit 142a, and the output FVa02 of the second delay unit 142b are input to the first horizontal difference calculation unit 144a.

  The first horizontal difference calculation unit 144a extracts a horizontal edge by extracting a horizontal difference using the outputs of the vertical LPF 141a and the first and second delay units 142a and 142b.

The input image data Va0, the output of the first line delay unit 140a, and the output of the second line delay unit 140b are also input to the first to third horizontal LPFs 143a, 143b, and 143c, respectively.
The first to third horizontal LPFs 143a, 143b, and 143c perform filtering for extracting a low frequency component in the horizontal direction.

The outputs FVa0, FVa1, and FVa2 of the first to third horizontal LPFs 143a, 143b, and 143c are respectively input to the first vertical difference calculation unit 144b.
The first vertical difference calculation unit 144b extracts vertical differences by using the outputs of the first to third horizontal LPFs 143a, 143b, and 143c to extract vertical edges.

The first delayed image data Vb0 is delayed by predetermined lines (for example, one line in the NTSC system and two lines in the PAL system) by the third and fourth line delay means 140c and 140d, respectively.
The vertical LPF 141b receives the first delayed image data Vb0, the output of the third line delay unit 140c, and the output of the fourth line delay unit 140d as inputs, and performs filtering in the vertical direction to obtain a low frequency component, that is, a luminance component. Extract.

  The output FVb00 of the vertical LPF 141b is delayed by a predetermined number (for example, one) of pixels by the third delay unit 142c, and further delayed by a predetermined number (for example, one) of pixels by the fourth delay unit 142d. The output FVb00 of the vertical LPF 141b, the output FVb01 of the third delay unit 142c, and the output FVb02 of the fourth delay unit 142d are input to the second horizontal difference calculation unit 144c.

  The second horizontal difference calculation unit 144c extracts a horizontal edge by extracting a horizontal difference using the output of the vertical LPF 141b and the outputs of the third and fourth delay units 142c and 142d.

The first delayed image data Vb0, the output of the third line delay unit 140c, and the output of the fourth line delay unit 140d are also input to the fourth to sixth horizontal LPFs 143d, 143e, and 143f, respectively.
The fourth to sixth horizontal LPFs 143d, 143e, and 143f perform filtering for extracting a low frequency component in the horizontal direction.

The outputs FVb0, FVb1, and FVb2 of the fourth to sixth horizontal LPFs 143d, 143e, and 143f are input to the second vertical difference calculation unit 144d, respectively.
The second vertical difference calculation unit 144d extracts vertical differences by using the outputs of the fourth to sixth horizontal LPFs 143d, 143e, and 143f, and extracts vertical edges.

  FIG. 8 shows an example of the first horizontal difference calculation unit 144a. The illustrated first horizontal difference calculation unit 144a includes first and second subtraction circuits 1443a and 1444a, a maximum value circuit 1445a, an average value circuit 1446a, and a selection circuit 1447a.

The first subtracting circuit 1443a outputs a value obtained by subtracting the output FVa02 of the second delay unit 142b from the output FVa01 of the first delay unit 142a.
The second subtracting circuit 1444a outputs a value obtained by subtracting the output FVa00 of the first vertical LPF 141a from the output FVa01 of the first delay unit 142a.
The maximum value circuit 1445a receives the outputs of the first and second subtraction circuits 1443a and 1444a and outputs the larger one.
The average value circuit 1446a receives the outputs of the first and second subtraction circuits 1443a and 1444a and outputs the average of both.

  The selection unit 1447a outputs one of the two input signals as the first horizontal difference signal HDa according to the edge synthesis setting signal EDC.

  FIG. 9 shows an example of the first vertical difference calculation unit 144b. The illustrated first vertical difference calculation unit 144b includes first and second subtraction circuits 1443b and 1444b, a maximum value circuit 1445b, an average value circuit 1446b, and a selection circuit 1447b.

The first subtraction circuit 1443b outputs a value obtained by subtracting the output FVa0 of the first horizontal LPF 143a from the output FVa1 of the second horizontal LPF 143b.
The second subtraction circuit 1444b outputs a value obtained by subtracting the output FVa2 of the third horizontal LPF 143c from the output FVa1 of the second horizontal LPF 143b.
The maximum value circuit 1445b receives the outputs of the first and second subtraction circuits 1443b and 1444b and outputs the larger one.
The average value circuit 1446b receives the outputs of the first and second subtraction circuits 1443b and 1444b and outputs the average of both.

  The selection unit 1447b outputs one of the two input signals as the first vertical difference signal VDa according to the edge synthesis setting signal EDC.

  FIG. 10 shows an example of the second horizontal difference calculation unit 144c. The illustrated second horizontal difference calculation unit 144c includes first and second subtraction circuits 1443c and 1444c, a maximum value circuit 1445c, an average value circuit 1446c, and a selection circuit 1447c.

The first subtracting circuit 1443c outputs a value obtained by subtracting the output FVb02 of the fourth delay unit 142d from the output FVb01 of the third delay unit 142c.
The second subtracting circuit 1444c outputs a value obtained by subtracting the output FVb00 of the second vertical LPF 141b from the output FVb01 of the third delay unit 142c.
The maximum value circuit 1445c receives the outputs of the first and second subtraction circuits 1443c and 1444c, and outputs the larger one.
The average value circuit 1446a receives the outputs of the first and second subtraction circuits 1443c and 1444c and outputs the average of both.

  The selection unit 1447c outputs one of the two input signals as the second horizontal difference signal HDb in response to the edge synthesis setting signal EDC.

  FIG. 11 shows an example of the second vertical difference calculation unit 144d. The illustrated second vertical difference calculation unit 144d includes first and second subtraction circuits 1443d and 1444d, a maximum value circuit 1445d, an average value circuit 1446d, and a selection circuit 1447d.

The first subtraction circuit 1443d outputs a value obtained by subtracting the output of the fourth horizontal LPF 143d from the output of the fifth horizontal LPF 143e.
The second subtracting circuit 1444d outputs a value obtained by subtracting the output of the sixth horizontal LPF 143f from the output of the fifth horizontal LPF 143e.
The maximum value circuit 1445d receives the outputs of the first and second subtraction circuits 1443d and 1444d, and outputs the larger one.
The average value circuit 1446d receives the outputs of the first and second subtraction circuits 1443d and 1444d and outputs the average of both.

  The selection unit 1447d outputs one of the two input signals as the second vertical difference signal VDb according to the edge synthesis setting signal EDC.

  The edge synthesis setting signal EDC is set in advance or prepared separately according to the user's preference, for example. When taking a first value, for example, “1”, the selection means 1447a, 1447b, 1447c. , 1447d select the outputs of the maximum value circuits 1445a, 1445b, 1445c, 1445d, respectively, and when taking a second value, for example, "0", the selection means 1447a, 1447b, 1447c, 1447d are the average value circuit 1446a. , 1446b, 1446c, and 1446d are selected. If the outputs of the maximum value circuits 1447a, 1447b, 1447c, and 1447d are selected, the edge detection is performed with the protruding and large portion as the maximum value, so that the detection becomes easy, but the average value circuits 1446a, 1446b, 1446c, and 1446d. There is an advantage that the number of false detections is less when the output is selected.

The output HDa of the first horizontal difference calculation unit 144a is input to the first ROM 145a and is converted into a four-stage edge signal in the ROM 145a. That is, the first ROM 145a acts as a discrimination means having three threshold values,
If the input (output of the first horizontal difference calculation unit 144a) HDa is less than the first threshold THa1, the output SVDa becomes a first value SVDa0, for example, “0”, and the input HDa is the first value If the threshold value THa1 is equal to or greater than the second threshold value THa2, the output SVDa is a second value SVDa1, for example, “1”, and the input HDa is equal to or greater than the second threshold value THa2 and less than the third threshold value THa3. If the output SVDa is a third value SVDa2, for example “2”, and the input HDa is equal to or greater than the third threshold THa3, the output SVDa is a fourth value SVDa3, for example “3”. Become.
Here, THa1 <THa2 <THa3 and SVDa0 <SVDa1 <SVDa2 <SVDa3.

  The output SVDa of the ROM 145a is input to the horizontal enlargement unit 146a. The horizontal enlargement unit 146a enlarges the output SVDa of the ROM 145a in the horizontal direction. The output of the horizontal enlarging means 146a is represented by the symbol EHDa.

  The output VDa of the first vertical difference calculation unit 144b is input to the second ROM 145b and converted into four-stage edge signals in the ROM 145b. That is, the second ROM 145b acts as a discriminating means having three threshold values, and if its input (output of the first vertical difference calculation unit 144b) VDa is less than the first threshold value TVa1, its output SVDa Becomes the first value SVDa0, for example, “0”, and the input VDa is equal to or higher than the first threshold value TVa1 and less than the second threshold value TVa2, the output SVDa is set to the second value SVDa1, for example, “1”. If the input VDa is greater than or equal to the second threshold value TVa2 and less than the third threshold value TVa3, the output SVDa becomes a third value SVDa2, for example, “2”, and the input VDa becomes the third threshold value. If it is equal to or greater than TVa3, the output SVDa becomes a fourth value SVDa3, for example, “3”. Here, TVa1 <TVa2 <TVa3 and SVDa0 <SVDa1 <SVDa2 <SVDa3.

  The output HDb of the second horizontal difference calculation unit 144c is input to the third ROM 145c and converted into four-stage edge signals in the ROM 145c. That is, the third ROM 145c acts as a discriminating means having three threshold values. If the input (output of the second horizontal difference calculation unit 144c) HDb is less than the first threshold value THb1, its output If SHDb is a first value SHDb0, eg, “0”, and the input HDb is greater than or equal to the first threshold value THb1 and less than the second threshold value THb2, the output SHDb is a second value SHDb1, eg, “1”. If the input HDb is greater than or equal to the second threshold value THb2 and less than the third threshold value THb3, the output SHDb is a third value SHDb2, eg, “2”, and the input HDb is greater than the third threshold value THb3. If it is equal to or greater than the threshold value THb3, the output SHDb is a fourth value SHDb3, for example, “3”. Here, THb1 <THb2 <THb3 and SHDb0 <SHDb1 <SHDb2 <SHDb3.

  The output SHDb of the ROM 145c is input to the horizontal enlargement unit 146b. The horizontal enlargement unit 146b enlarges the output SHDb of the ROM 145c in the horizontal direction. The output of the horizontal enlarging means 146b is represented by the symbol EHDb.

  The output VDb of the second vertical difference calculation unit 144d is input to the fourth ROM 145d and converted into a four-stage edge signal in the ROM 145d. The fourth ROM 145d acts as a discriminating means having three threshold values, and if its input (output of the second vertical difference calculation unit 144d) VDb is less than the first threshold value TVb1, its output SVDb is If the first value SVDb0 is, for example, “0” and the input VDb is greater than or equal to the first threshold TVb1 and less than the second threshold TVb2, the output SVDb is the second value SVDb1, for example “1”. If the input VDb is greater than or equal to the second threshold TVb2 and less than the third threshold TVb3, the output SVDb becomes a third value SVDb2, for example, “2”, and the input VDb becomes the third threshold TVb3. If it is above, the output SVDb becomes the fourth value SVDb3, for example, “3”. Here, TVb1 <TVb2 <TVb3 and SVDb0 <SVDb1 <SVDb2 <SVDb3.

  The outputs EHDa and EHDb of the first and second horizontal enlargement means 146a and 146b and the outputs SVDa and SVDb of the second and fourth ROMs 145b and 145d are input to the edge synthesis unit 147, respectively.

  FIG. 12 shows an example of the edge synthesis unit 147. The illustrated edge synthesis unit 147 includes first to third maximum value circuits 1471, 1472, 1475, first to third selection means 1473, 1474, 1477, and an average value circuit 1476.

The first maximum value circuit 1471 receives the output EHDa of the first horizontal enlargement unit 146a and the output EHDb of the second horizontal enlargement unit 146b, and outputs the larger one.
The second maximum value circuit 1472 receives the output SVDa of the second ROM 145b and the output SVDb of the fourth ROM 145d, and outputs the larger one.
The first selection unit 1473 receives the output EHDa of the first horizontal enlargement circuit 146a and the output of the first maximum value circuit 1471, and selects and outputs either of them.
The second selection means 1474 receives the output SVDa of the second ROM 145b and the output of the second maximum value circuit 1472, and selects and outputs either of them.
The third maximum value circuit 1475 receives the output of the first selection unit 1473 and the output of the second selection unit 1474, and outputs the larger of the two.
The average value circuit 1476 receives the output of the first selection means 1473 and the output of the second selection means 1474, and outputs the average of both.
The third selection means 1477 receives the output of the third maximum value circuit 1475 and the output of the average value circuit 1476, and selects and outputs either of them.

The selection in the first and second selection means 1473 and 1474 is controlled by the edge synthesis setting signal ECa.
The edge synthesis setting signal ECa is set in advance or prepared separately according to the user's preference, for example. When taking the first value, for example, “1”, the selection means 1473 and 1474 are: When selecting the outputs of the maximum value circuits 1471 and 1472 and taking the second value, for example, “0”, the selection means 1473 and 1474 respectively select the output EHDa of the horizontal enlargement circuit 146a and the output SVDa of the ROM 145b. . If the outputs of the maximum value circuits 1471 and 1472 are selected, an edge is detected with the protruding and large part as the maximum value, so detection is easy, but the output EHDa of the horizontal enlargement circuit 146a and the output SVDa of the ROM 145b are selected. The advantage is that there are fewer false detections.

Selection in the selection means 1477 is controlled by the edge synthesis setting signal ECb. The edge synthesis setting signal ECb is set in advance or prepared separately according to the user's preference, for example, and when selecting a first value, for example, “1”, the selection unit 1477 has a maximum value. When selecting the output of the circuit 1475 and taking a second value, for example, “0”, the selection unit 1477 selects the output of the average value circuit 1476. If the output of the maximum value circuit 1475 is selected, the edge is detected with the protruding and large portion as the maximum value, which makes detection easier. However, if the output of the average value circuit 1476 is selected, there are fewer false detections. There is an advantage to say.
The output of the selection unit 1477 is output as edge data EDG that is an output signal of the edge detection unit 14.

FIG. 13 shows an example of the stillness determination means 15 shown in FIG.
The illustrated stillness determination unit 15 includes an inter-frame difference detection unit 151, a color subcarrier frequency band detection unit 152, a synthesis unit 153, and a selection unit 154.

Input image data Va0, first delay image data Vb0, and second delay image data Vc0 are input to the inter-frame difference detection means 151.
The inter-frame difference detection unit 151 detects a difference between the input image data Va0, the first delay image data Vb0, and the second delay image data Vc0, and includes a difference detection unit 1511 and a prefilter 1512. And a comparison unit 1513 and an isolated point removal unit 1514.

  For example, as shown in FIG. 14, the difference detection unit 1511 calculates a difference between the input image data Va0 and the first delay image data Vc0, and a subtraction circuit 15111 that calculates the difference between the input image data Va0 and the first delay image data Vb0. A subtracting circuit 15112 to be obtained and means for synthesizing the output of the subtracting circuit 15111 and the output of the subtracting circuit 15112, for example, synthesizing means 15113 for outputting the larger one of them as the difference signal Dabc.

  The prefilter 1512 removes the high frequency noise component of the output of the difference detection means 1511. The prefilter 1512 is configured, for example, in the same manner as the prefilter 1122 of FIG. 2, and its operation mode is selected by a prefilter selection signal SPFs (supplied instead of the selection signal SPFy of FIG. 2).

The comparison unit 1513 receives the output signal of the prefilter 1512 and outputs a signal according to a comparison result with a preset threshold value (inter-frame difference detection level) THD.
That is, if the difference detection level THD is smaller than the inter-frame difference detection level, it is determined that the luminance signal is stationary between frames, and the output is set to “1”. The output is set to “0”.

  The isolated point removing unit 1514 compares the value of the input (output of the comparison unit 1513) for each pixel with the value of the input for pixels around the pixel, and the value of the input for each pixel (current pixel). Is “1” and the input value for the surrounding pixels is “0”, the input value for each pixel is changed to “0” and output. The isolated point removing unit 1514 may not be provided, and the output of the comparing unit 1513 may be used as the output of the inter-frame difference detecting unit 151 as it is.

The input image data Va0 is also input to the color carrier frequency band detecting means 152.
The color subcarrier frequency band detection unit 152 detects a color frequency band luminance signal, and includes a horizontal BPF 1521, a comparison unit 1522, and a horizontal enlargement unit 1523.

The horizontal BPF 1521 receives the input image data Va0 and extracts a component near the color signal band.
The comparison unit 1522 compares the output of the horizontal BPF 1521 with a predetermined threshold value (color carrier detection level) THE, and if it is greater than the color carrier detection level THE, determines that it is a color frequency band luminance signal and sets the output to “1”. .

  The horizontal enlarging means 1523 enlarges the output signal of the comparing means 1522 in the horizontal direction. Specifically, the value of the input signal (output signal of the comparison unit 1522) for each pixel is “0”, and the value of the input signal (output signal of the comparison unit 1522) for the previous or subsequent pixel is “1”. "", The value of the output signal is set to "1" even if the value of the input signal for each pixel is "0". The horizontal enlargement unit 1523 may not be provided, and the output of the comparison unit 1522 may be used as the output of the color subcarrier frequency band detection unit 152 as it is.

  The combining unit 153 combines the output of the inter-frame difference detection unit 151 and the output of the color carrier frequency band detection unit 152. The synthesizing unit 153 is configured by an OR circuit that sets the output signal to “1” when one of the two input signals is “1”, for example.

  The selection means 154 selects and outputs a determination signal that is a combination result or a value “0” by the selection means 154 that selects one of the output of the combining means 153 or the value “0” according to the stillness determination setting signal STJ. . The stillness determination setting signal STJ is set in advance or is prepared separately. When taking a first value, for example, “1”, the selection unit 154 selects the output of the synthesis circuit 153 and outputs the second value. For example, the selection means 154 selects “0”. The stationary determination setting signal STJ is set to “1” during normal operation, but is set to “0” during testing, for example.

  In the motion detection circuit 1 according to the first embodiment, the input image data Va0 and the input image data Va0 are delayed by an α frame period (α = 1 for the NTSC system, α = 2 for the PAL system). 1 delayed image data Vb0 and second delayed image data Vc0 obtained by delaying the first delayed image data Vb0 by an α frame period, that is, by delaying the input image data Va0 by 2α frame periods, are input. The color difference detection means 12 receives input image data and first delayed image data, that is, two signals having a difference in α frame period between them, and the color luminance difference detection means 13 receives input image data and The second delayed image data, that is, two signals having a difference of 2α frame period between them are input.

  In the luminance difference detection means 11, luminance signal components of two input signals are extracted by horizontal LPFs 1111 and 1112, respectively, and a difference signal between α frames of the luminance signal is extracted by subtraction using a subtraction circuit 1113, and an absolute value circuit The absolute value is converted into the absolute value by 1121, and the high frequency noise component is removed by the prefilter 1122. For removing the high frequency noise component in the pre-filter 1122, one of three means of the horizontal LPF 2223, the intermediate value circuit 2224, and the maximum value circuit 2225 is used. Which of these is used is selected by a prefilter selection signal SPFy. It is also possible to select a mode in which high frequency noise component removal by the above three means is not performed by the prefilter selection signal SPFy.

  Sensitivity conversion is performed on the output of the pre-filter 1122 by the ROM 1123. The sensitivity conversion characteristic is adjusted by the sensitivity intercept setting signal SXy and the inclination setting signal SGy.

The output signal of the ROM 1123 is adjusted so as to avoid being isolated from the surroundings and being judged as a motion signal by the isolated point removing unit 113.
The output of the isolated point removing unit 113 (luminance difference signal DFy) is output as motion data detected by the luminance difference detecting unit 11.

In the color difference detection means 12, the color signal components of the two input signals are extracted by the horizontal BPFs 1211 and 1212, the output of the horizontal BPF 1212 is inverted by the inversion circuit 1215, and the signal is subtracted from the output of the horizontal BPF 1211 by the subtraction circuit 1213. As a result, a difference signal between the α frames of the color signal is extracted.
The inversion in the inversion circuit 1215 has a meaning as compensation for the inversion of the phase of the color signal between α frames.

The difference signal output from the subtraction circuit 1213 is converted to an absolute value by the absolute value circuit 1221, and the high frequency noise component is removed by the prefilter 1222.
Sensitivity conversion is performed on the output FADc of the pre-filter 1222 by the ROM 1223. The sensitivity conversion characteristic is adjusted by the sensitivity intercept setting signal SXc and the inclination setting signal SGc.

  The output signal of the ROM 1223 is expanded in the horizontal direction by the horizontal expansion means 123. The output (color difference signal DFc) of the horizontal enlargement unit 123 is output as motion data detected by the luminance difference detection unit 12.

  In the color luminance difference detection means 13, a difference signal between 2α frames is extracted by subtracting two input signals using a subtraction circuit 1313, and is converted into an absolute value by an absolute value circuit 1321. By 1322, the high frequency noise component is removed.

  The ROM 1323 converts the sensitivity of the output FADyc of the prefilter 1322. The sensitivity conversion characteristic is adjusted by the sensitivity intercept setting signal SXyc and the inclination setting signal SGyc.

  The motion signal output from the ROM 1323 is expanded in the horizontal direction by the horizontal expansion means 133. The output (luminance color difference signal DFyc) of the horizontal enlargement unit 133 is output as motion data detected by the color luminance difference detection unit 13.

The edge detection means 14 extracts edge data in the input image data and the first delayed image data Vb0.
Regarding the input image data, with respect to the luminance component extracted by the vertical LPF 141a using the delayed image data delayed by the first and second line delay means 140a and 140b and the input image data Va0 (that is, data for three lines), By using the outputs of the first and second delay units 142a and 142b to extract a horizontal difference by the first horizontal difference calculation unit 144a, a horizontal edge is extracted, and the first to third horizontal LPFs 143a, 143b, and 143c are extracted. The vertical difference is extracted and the vertical edge is extracted by the first vertical difference calculation unit 144b using the respective outputs.

  The horizontal edge of the input image data detected by the first horizontal difference calculation unit 144a is converted into a four-stage edge signal by the ROM 145a, and the vertical edge of the input image data detected by the first vertical difference calculation unit 144b. Is converted into a 4-step edge signal by the ROM 145b.

For the delayed image data Vb0, the luminance component extracted by the vertical LPF 141b using the signals Vb1 and Vb2 delayed by the third and fourth line delay means 140c and 140d and the delayed image data Vb0 (ie, data for three lines). For the second to fourth horizontal LPFs 143d and 143e, the second horizontal difference calculation unit 144c extracts the horizontal difference by using the outputs of the third and fourth delay units 142c and 142d to extract the horizontal edge. , 143f, the vertical difference is extracted by the second vertical difference calculation unit 144d to extract the vertical edge.
The horizontal edge of the delayed image data Vb0 detected by the second horizontal difference calculation unit 144c is converted into a four-stage edge signal by the ROM 145c, and the delay image data Vb0 detected by the second vertical difference calculation unit 144d is converted. The vertical edge is converted into a four-stage edge signal by the ROM 145d.

The four edge signals are synthesized in the edge synthesis unit 147 according to the edge synthesis setting signal ECa and the edge synthesis setting signal ECb.
The output of the synthesizing unit 147 is input as edge data EDG to the luminance difference detecting unit 11, the color difference detecting unit 12, and the color luminance difference detecting unit 13, and is used to adjust sensitivity conversion in the ROMs 1123, 1223, and 1323 of the respective detecting units. It is done.

The stillness determination means 15 determines whether or not the luminance signal is stationary between frames, and outputs the determination result as a determination signal STL.
The inter-frame difference detection unit 151 obtains the difference between the input image data Va0 and the first delay image data Vb0 and the difference between the input image data Va0 and the second delay image data Vc0, and further determines the maximum of these differences. A high frequency noise component is removed by a pre-filter 1512, and a signal indicating a comparison result with a preset threshold value (inter-frame difference detection level) THD is output by the comparison unit 1513. Is done. That is, when the output of the prefilter 1512 is smaller than the inter-frame difference detection level THD, it is determined that the luminance signal is stationary between frames and the output is set to “1”.
The isolated point removing unit 1514 outputs “0” when only one point is “1” for the preceding and following pixels.

The color subcarrier frequency band detection means 152 extracts components near the color signal band from the input image data by the horizontal BPF 1521, and the comparison means 1522 determines that the input signal is a color frequency band luminance signal when it is greater than the color carrier detection level THE. The output is set to “1”.
In the horizontal enlargement means 1523, the output signal of the comparison means 1522 is enlarged in the horizontal direction.
The output signal of the horizontal enlarging means 1523 is output to the synthesizing means 153 as the output STL of the color carrier frequency band detecting means 152.
The synthesizing unit 153 sets the output signal to “1” when either one of the two input signals takes “1”.
The selection unit 154 selects and outputs the determination signal as a combination result or the value “0” by the selection unit 154 that selects one of the output of the combining unit 153 or the value “0” according to the stillness determination setting signal STJ. .

According to the above-described configuration of motion detection, for example, in the case of an NTSC signal, the color difference is detected by detecting the motion between one frame of luminance by the luminance difference detecting means 11 for detecting the difference signal of the luminance signal and detecting the difference signal of the color signal. The detection means 12 can detect the movement between the frames of the component close to the color subcarrier frequency, and the color luminance difference detection means 13 can detect the movement of the color signal and the luminance signal between the two frames.
Thereby, for example, even when the color signal moves greatly in one frame and returns to the same position as two frames after two frames, it is possible to accurately detect the movement of the signal without omission of detection. .

  Further, according to the above-described configuration of motion detection, for example, in the case of a static input signal with a large luminance oblique component, the luminance signal exists up to the vicinity of the color carrier frequency component, so that the color difference detection means 12 detects the color signal difference signal. However, the detection component tends to increase despite the absence of color signals. In order to reduce this erroneous detection, the comparison circuit 1513 of the inter-frame difference detection means 151 increases the threshold value (inter-frame difference detection level) THD to be compared with the difference value. Outputs “0”. Thereby, even in the case of a stationary input signal with many luminance oblique components, it becomes difficult to perform erroneous detection.

  However, when the value of the threshold value THD to be compared with the difference value by the comparison circuit 1513 is set to be large as described above, it is likely to cause a still misjudgment that determines that the signal is a still signal regardless of the movement in an image having a color movement. . As a countermeasure against this, the selection unit 1343 in the color luminance difference detection unit 13 selects and sets the fifth inclination setting signal SGyc4 having a large value so that it can be easily determined as a movement, and outputs it as SGyc. An error in determining the value of the motion signal MVS (motion detection) can be prevented.

  The color difference detection unit 12 can also select and output the fifth inclination setting signal SGc4 by switching the state of the selection unit 1443 as necessary.

In the above embodiment, the luminance difference detection unit 11 performs isolated point removal, the color difference extraction unit 12 performs horizontal expansion, and the color luminance difference detection unit 13 performs horizontal expansion. To detect
Each detection means may be changed to a configuration in which isolated point removal and horizontal enlargement are replaced (the other is used instead of one) or both are used.

In the above embodiment, the maximum value circuit 16 that detects the maximum value of the output of the luminance difference detection unit 11, the output of the color difference detection unit 12, and the output of the color luminance difference detection unit 13 is used. A combining circuit that combines the output of the means 11, the output of the color difference detecting means 12, and the output of the color luminance difference detecting means 13 by another method may be used.
In the above embodiment, the spatiotemporal expansion means 17 that expands the difference signal in the time direction and the spatial direction is used. Instead, an expansion means that expands only in the time direction may be used. It is also possible to use an enlargement means for enlarging only the image.

  As an application example of the present invention, the present invention can be applied to a luminance signal color signal separation circuit that separates a television signal into a luminance signal and a color signal, or a motion detection circuit in the luminance signal color signal separation circuit.

It is a block diagram which shows the motion detection apparatus of Embodiment 1 of this invention. It is a block diagram which shows an example of the brightness | luminance difference detection means 11 shown by FIG. FIG. 3 is a block diagram showing an example of a pre-filter 1122 shown in FIG. It is explanatory drawing which shows an example of the sensitivity characteristic of ROM1123 shown by FIG. It is a block diagram which shows an example of the color difference detection means 12 shown by FIG. It is a block diagram which shows an example of the color luminance difference detection means 13 shown by FIG. It is a block diagram which shows an example of the edge detection means 14 shown by FIG. It is a block diagram which shows an example of the 1st horizontal difference calculating part 144a shown by FIG. It is a block diagram which shows an example of the 1st vertical difference calculating part 144b shown by FIG. It is a block diagram which shows an example of the 2nd horizontal difference calculating part 144c shown by FIG. It is a block diagram which shows an example of the 2nd vertical difference calculating part 144d shown by FIG. It is a block diagram which shows an example of the edge synthetic | combination means 147 shown by FIG. It is a block diagram which shows an example of the stationary determination means 15 shown by FIG. It is a block diagram which shows an example of the difference detection means 1511 shown by FIG.

Explanation of symbols

  11 brightness difference detection means, 12 color difference detection means, 13 color brightness difference detection means, 14 edge detection means, 15 stillness determination means, 16 maximum value circuit, 17 spatiotemporal expansion means, 111 brightness difference extraction means, 112 sensitivity conversion means 113 Isolated point removing means, 114 Inclination setting means, 121 Color difference extraction means, 122 Sensitivity conversion means, 123 Horizontal enlargement means, 124 Inclination setting means, 131 Color luminance difference extraction means, 132 Sensitivity conversion means, 133 Horizontal enlargement means, 134 Inclination setting means, 141a, 141b Vertical LPF, 142a, 142b, 142c, 142d Delay means, 143a, 143b, 143c, 143d, 143e, 143f Horizontal LPF, 144a, 144c Horizontal difference detection section, 144b, 144d Vertical difference detection 145a, 145b, 145c, 145d ROM, 146a, 146b horizontal enlargement means, 147 edge composition means, 151 inter-frame difference detection means, 152 color subcarrier frequency band detection means, 1111, 1112 horizontal LPF, 1113 subtraction circuit, 1121 Absolute value circuit, 1122 Prefilter, 1123 ROM, 1141 Selection means, 1213 Subtraction circuit, 1215 Inversion circuit, 1221 Absolute value circuit, 1222 Prefilter, 1223 ROM, 1313 Subtraction circuit, 1321 Absolute value circuit, 1322 Prefix Filter, 1323 ROM, 2221, 2222 delay circuit, 2223 horizontal LPF, 2224 intermediate value circuit, 2225 maximum value circuit, 2226 selection means.

Claims (9)

An input video signal, a first delayed signal obtained by delaying the input video signal by a predetermined number of frame periods, and a second delayed signal obtained by delaying the predetermined number of frames by twice a frame period;
Luminance difference detection means for detecting a difference in luminance signal from the input video signal and the first delay signal;
Color difference detection means for detecting a difference in color signal from the input video signal and the first delay signal;
Color luminance difference detection means for detecting a difference between a luminance signal and a color signal from the input video signal and the second delay signal;
Combining means for combining the output of the luminance difference detecting means, the output of the color difference detecting means, and the output of the color luminance difference detecting means;
Edge detection means for determining the presence or absence of an edge in the image from the input video signal and the first delay signal;
Stillness determination means for determining whether a luminance signal is stationary between frames from the input video signal, the first delay signal, and the second delay signal,
The detection sensitivity in the luminance difference detection means is adjusted according to the determination result by the edge determination means,
The detection sensitivity in the color difference detection unit is adjusted according to the determination result by the edge determination unit and the determination result by the stationary determination unit,
The color luminance difference detection means selects whether to adjust the detection sensitivity according to the determination result by the edge determination means and the determination result by the stillness determination means, or to set a predetermined color luminance difference detection inclination setting value. A motion detection circuit characterized in that   The color difference detection means can select whether the detection sensitivity is adjusted according to the determination result by the edge determination means and the determination result by the stillness determination means, or to be a predetermined inclination setting value for color difference detection The motion detection circuit according to claim 1, wherein:   The color luminance difference detecting means has means for storing the predetermined color luminance difference detection inclination setting value, an inclination setting value determined according to a determination result by the edge determination means and a determination result by the stationary determination means. The motion detection circuit according to claim 1, further comprising means for selecting one of them.   The color difference detection means includes: a means for storing the predetermined color luminance difference detection inclination setting value; and a slope setting value determined according to a determination result by the edge determination means and a determination result by the stillness determination means. The motion detection circuit according to claim 2, further comprising: means for selecting. The color difference detecting means is
A first horizontal bandpass filter that receives the input video signal;
A second horizontal bandpass filter having the first delayed signal as an input;
Inverting means for inverting the phase of one of the outputs of the first and second horizontal bandpass filters;
A subtraction circuit for obtaining a difference between the output of the inverting means and the other output of the first and second horizontal bandpass filters;
A pre-filter for removing high-frequency noise components of the output of the subtraction circuit;
The motion detection circuit according to claim 1, further comprising: a ROM that receives an output of the prefilter and performs sensitivity conversion. The interframe difference means for detecting that the difference between the input video signal and the first and second delayed signals is greater than or equal to a predetermined first threshold, the stillness determining means;
Color subcarrier frequency band detecting means for detecting that a luminance signal in a color subcarrier frequency band of the input video signal is equal to or greater than a predetermined second threshold;
When the inter-frame difference means detects that the difference between the input video signal and the first and second delayed signals is greater than or equal to the predetermined threshold, or the color subcarrier frequency band detection means To generate a signal indicating that the luminance signal is stationary between the frames when it is detected that the luminance signal in the color subcarrier frequency band of the input video signal is greater than or equal to the predetermined threshold. The motion detection circuit according to claim 1, further comprising: means.   The motion detection circuit according to claim 1, further comprising a spatiotemporal expansion unit that expands the difference signal output from the combining unit in a time direction or a spatial direction.   2. The motion according to claim 1, wherein the synthesizing unit outputs the largest one of the output of the luminance difference detecting unit, the output of the color difference detecting unit, and the output of the color luminance difference detecting unit. Detection circuit.   The motion detection circuit according to claim 1, wherein the input video signal is a composite color television signal.

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