JP5247479B2 - Video signal processing device - Google Patents

Description

  The present invention relates to a video signal processing apparatus that detects and removes noise components mixed in a signal obtained by conversion when a composite signal is converted into a component signal.

When a conventional video signal processing apparatus separates a composite signal into luminance signal color signal separation (Y / C separation) for converting a component signal without using a two-dimensional luminance signal color signal separation filter including a line memory. The color signal boundary in the vertical direction of
Dot interference (color signal leakage into the luminance signal, cross luminance) generated at the boundary portion of the color signal inclined 45 degrees when separated without using a three-dimensional luminance signal color signal separation filter having a frame memory In other words, there is a problem in that the disturbing component is visually recognized even in the video output.

  As an improvement measure, it is known to detect dot interference using a bandpass filter for extracting a color subcarrier band and a time axis direction filter (see, for example, Patent Document 1). It is also known to perform dot interference determination using a band separation filter, an amplitude stability detection circuit, a phase stability detection circuit, and a level stability detection circuit (see, for example, Patent Document 2).

JP-A-2005-130237 Japanese Patent Laying-Open No. 2007-221407 (page 14, FIG. 2)

  SUMMARY OF THE INVENTION An object of the present invention is to provide a video signal processing apparatus capable of removing dot interference generated when converting a composite signal into a component signal.

The video signal processing apparatus of the present invention is
In a video signal processing apparatus that removes interference components of a component signal obtained by separating a luminance signal and a color signal from a composite signal,
A dot component that receives the first , second, and third component signals having a time difference in frame units between them, detects a motion signal excluding the dot interference component, and outputs a dot component-removed motion signal indicating the detection result Removal motion detection means;
The first and second component signals and the dot component removal motion signal are input,
When the dot component removal motion signal indicates that it is determined to be a stationary signal or an interference component, a filter operation for removing the interference component is performed on the first and second component signals. A dot interference removal means ,
The dot component removal motion detection means includes:
A 1-frame difference calculation circuit for obtaining a 1-frame difference based on the first and second component signals;
A two-frame difference calculation circuit for obtaining a difference between two frames based on the first and third component signals;
First carrier band extraction means for extracting a carrier band component signal from the output of the inter-frame difference calculation circuit;
Second carrier band extraction means for extracting a carrier band component signal from the output of the difference calculation circuit between the two frames;
A motion detection circuit that outputs a motion detection signal indicating a motion detected based on the difference between the one frame and the difference between the two frames;
A dot disturbance detection circuit which receives the output signal of the first carrier band extraction means and the output signal of the second carrier band component extraction means and outputs a dot disturbance detection signal indicating dot disturbance;
A synthesis circuit that synthesizes the motion detection signal and the dot disturbance detection signal and outputs the dot component removal motion signal;
The motion detection circuit increases the value of the motion detection signal when at least one of the difference between the one frame and the difference between the two frames is large;
If the input signal is a motion signal, the dot disturbance detection circuit calculates the value of the dot disturbance detection signal if the input signal is a motion signal. If the dot interference is reduced, increase the value of the dot interference detection signal.
The synthesis circuit is characterized in that when the value of the dot disturbance detection signal is large, the dot component removal motion signal is made smaller than the motion detection signal .

  According to the present invention, there is an effect of eliminating dot interference generated when converting a composite signal into a component signal without blurring an image in the case of a motion signal.

It is a block diagram which shows the video signal processing apparatus of Embodiment 1 of this invention. It is a block diagram which shows an example of the dot disturbance removal circuit 3 of FIG. FIG. 2 is a block diagram illustrating an example of a dot component removal motion detection circuit 4 in FIG. 1. FIG. 4 is a block diagram illustrating an example of a motion detection circuit 43 in FIG. 3. FIG. 4 is a block diagram illustrating an example of a dot interference detection circuit 44 in FIG. 3. FIG. 4 is a block diagram illustrating an example of a synthesis circuit 45 in FIG. 3. It is a block diagram which shows an example of the dot component removal motion detection circuit 4a used with the video signal processing apparatus of Embodiment 2 of this invention. It is a block diagram which shows an example of the synthetic | combination circuit 45a of FIG. FIG. 6 is a block diagram showing a dot interference removal circuit 3a used in the video signal processing device according to the second embodiment. It is a block diagram which shows the dot component removal motion detection circuit 4b used with the video signal processing apparatus of Embodiment 3 of this invention. It is a block diagram which shows an example of the synthetic | combination circuit 45b of FIG. It is the schematic which shows the outline of the magnitude | size and shape of the image before and after the screen shape and format conversion. It is the schematic which shows the pixel count of a conversion image. It is a block diagram which shows the dot component removal motion detection circuit 4c used with the video signal processing apparatus of Embodiment 4 of this invention. It is a block diagram which shows the dot component removal motion detection circuit 4d used with the video signal processing apparatus of Embodiment 5 of this invention. It is a block diagram which shows the video signal processing apparatus of Embodiment 6 of this invention. It is a block diagram which shows an example of the dot component removal motion detection circuit 4e of FIG.

Embodiment 1 FIG.
FIG. 1 shows a video signal processing apparatus according to Embodiment 1 of the present invention. The illustrated video signal processing apparatus includes a first 1-frame delay circuit 5a, a second 1-frame delay circuit 5b, a dot disturbance removal circuit (interference component removal circuit) 3, and a dot component removal motion detection circuit 4. Prepare.
A component signal (brightness signal) VS0 of the current frame that is a signal input from the input port 1 is referred to as a first 1-frame delay circuit 5a and a dot interference removal circuit 3 Is input to the dot component removal motion detection circuit 4.

The first one-frame delay circuit 5a delays the current frame signal VS0 by one frame period and outputs a one-frame delay signal VS1.
The second 1-frame delay circuit 5b delays the 1-frame delay signal VS1 by one frame period and outputs a 2-frame delay signal VS1.
The present invention is not limited to the configuration using the delay circuit as described above, and any component signal may be used as long as component signals having a time difference in units of frames can be obtained.

  The dot component removal motion detection circuit 4 receives the 0-frame delay signal VS0, the 1-frame delay signal VS1 and the 2-frame delay signal VS2, and based on these signals, a signal indicating the dot component removal motion detection result (dot component removal motion signal) ) Generate and output MWD.

The dot disturbance removal circuit 3 uses a dot component removal motion signal MWD as a control signal, and a signal obtained by performing a three-dimensional filter operation and a filter operation for removing an interference component from the input 0 frame delay signal VS0 and 1 frame delay signal VS1. The signal not to be processed is mixed at a rate corresponding to the dot component removal motion signal MWD and output as a dot disturbance removal video signal VSm.
As the signal not subjected to the filter operation, for example, the 0 frame delay signal VS0 itself or the 1 frame delay signal VS1 itself is used. Note that a signal obtained by delaying a signal not subjected to the filter operation by a processing time required for the filter operation may be used.

FIG. 2 shows an example of the dot interference removal circuit 3 of FIG. The illustrated dot interference removal circuit 3 includes a filter 31 and a mixing circuit 32. The 0 frame delay signal VS 0 and the 1 frame delay signal VS 1 input to this circuit are input to the filter 31, and the output signal VSf subjected to the three-dimensional smoothing process is sent to the mixing circuit 32. The output VSf of the filter 31 and the one-frame delay signal VS1 are input to the mixing circuit 32, and a mixing operation is performed according to the dot component removal motion signal MWD.
The output of the mixing circuit 32 becomes the dot interference removal video signal VSm.

  The dot component removal motion signal MWD output from the dot component removal motion detection circuit 4 has a relatively large value (there is motion even after the dot component is removed (it is determined that there is a relatively large motion)). In this case, the mixing circuit 32 performs mixing so that the mixing ratio of the one-frame delay signal VS1 is large, and the dot component removal motion signal MWD has a relatively small value (there are many dot disturbing components or the input signal is large). When it is determined that the signal is a static signal), the mixing circuit 32 performs mixing so that the mixing ratio of the filter output VSf becomes large.

  FIG. 3 shows an example of the dot component removal motion detection circuit 4 of FIG. The illustrated dot component removal motion detection circuit 4 includes a one-frame difference calculation circuit 41, a two-frame difference calculation circuit 42, a motion detection circuit 43, a dot disturbance detection circuit 44, and a synthesis circuit 45.

  The 0-frame delay signal VS0 input to this circuit is input to the 1-frame difference calculation circuit 41 and the 2-frame difference calculation circuit 42, and the 1-frame delay signal VS1 is input to the 1-frame difference calculation circuit 41. The 2-frame delay signal VS2 is input to the inter-frame difference calculation circuit 42.

The inter-frame difference calculation circuit 41 obtains the absolute value of the difference between the 0-frame delay signal VS0 and the 1-frame delay signal VS1, and outputs it as the inter-frame difference signal DV1.
The inter-frame difference calculation circuit 42 obtains an absolute value of the difference between the 0-frame delay signal VS0 and the 2-frame delay signal VS2, and outputs it as the inter-frame difference signal DV2.
In the present application, the difference represented by the inter-frame difference signal DV1 may be represented by the same symbol DV1, and the difference represented by the two-frame difference signal DV1 may be represented by the same symbol DV2. The same applies to other signals.
The inter-frame difference signal DV1 output from the inter-frame difference calculation circuit 41 is input to the motion detection circuit 43 and the dot disturbance detection circuit 44, and is output from the inter-frame difference calculation circuit 42. Is also input to the motion detection circuit 43 and the dot disturbance detection circuit 44.

The motion detection circuit 43 detects a motion based on the 1-frame difference signal DV1 and the 2-frame difference signal DV2, and outputs a motion detection signal MN.
The dot disturbance detection circuit 44 detects dot disturbance based on the inter-frame difference signal DV1 and the two-frame difference signal DV2, and outputs a dot disturbance detection signal BG.

The motion detection signal MN output from the motion detection circuit 43 and the dot interference detection signal BG output from the dot interference detection circuit 44 are input to the synthesis circuit 45.
The combining circuit 45 combines the motion detection signal MN and the dot interference detection signal BG, and outputs the combined result as a dot component removal motion signal MWD.

  FIG. 4 shows an example of the motion detection circuit 43 of FIG. The illustrated motion detection circuit 43 includes a maximum value circuit 431. The inter-frame difference signal DV1 and the two-frame difference signal DV2 input to the motion detection circuit 43 are input to the maximum value circuit 431, and the maximum value circuit 431 includes an inter-frame difference signal DV1 The larger one (maximum value) of the difference) and the difference signal DV2 between two frames DV2 (the difference between the two frames represented by) is output as the motion detection signal MN. Therefore, the motion detection signal MN increases when at least one of the inter-frame difference signal DV1 and the two-frame difference signal DV2 is large. The output of the maximum value circuit 431 becomes the output of the motion detection circuit 43 (motion detection signal MN).

FIG. 5 shows an example of the dot disturbance detection circuit 44 of FIG. The illustrated dot interference detection circuit 44 includes a subtraction circuit 441 and a limiter 442.
The inter-frame difference signal DV1 and the inter-frame difference signal DV1 and the inter-frame difference signal input to the dot disturbance detection circuit 44 are input to the subtraction circuit 441. The subtraction circuit 441 is an inter-frame difference signal DV1 (represented by an inter-frame difference). Is subtracted from the difference signal DV2 between two frames (difference between two frames represented by), and a subtraction result ED is output.
If it is a motion signal (if the video signal is a video signal of the image motion part), the difference DV1 between 1 frame and the difference DV2 between 2 frames will be large, but if it is dot interference, the difference DV1 between 1 frame will be On the other hand, the difference DV2 between two frames becomes smaller. This is because the color carrier phase of a signal separated by one frame has an opposite phase, whereas the color carrier phase of a signal separated by two frames has the same phase. From this, the subtraction result ED is a small value in the case of a motion signal, but the subtraction result ED is large in the case of dot interference.
The limiter 442 receives the subtraction result ED and outputs a value limited so as not to become a negative value. That is, if the subtraction result ED is negative, the output BG of the limiter 442 is 0. If the subtraction result ED is not negative, the subtraction result ED is output from the limiter 442 as it is.

FIG. 6 shows an example of the synthesis circuit 45 of FIG. The illustrated synthesis circuit 45 includes a subtraction circuit 451 and a limiter 452. The motion detection signal MN and the dot disturbance detection signal BG input to the synthesis circuit 45 are input to the subtraction circuit 451. The subtraction circuit 451 subtracts the dot disturbance detection signal BG from the motion detection signal MN and outputs a subtraction result FD. .
If the signal is a motion signal, the motion detection signal MN increases. However, if the component signal is a dot interference (including a dot interference component), the dot interference detection signal BG increases. Although the value of FD increases, the value of the subtraction result FD decreases if dot interference occurs.
The limiter 452 receives the subtraction result FD, and outputs a value restricted so as not to become a negative value as the dot component removal motion signal MWD. That is, if the subtraction result FD is negative, the dot component removal motion signal MWD is 0. If the subtraction result FD is not negative, the subtraction result FD is output as it is from the limiter 452 as the dot component removal motion signal MWD.

  With the above configuration, the motion detection circuit 43 detects the degree of motion and the dot interference detection circuit 44 detects the degree of dot interference using the 1-frame difference signal DV1 and the 2-frame difference signal DV2.

In the dot component removal motion detection circuit 4 of the present invention, the dot component is not only determined according to the combination of the “degree of movement” and the “degree of dot interference”, but also the “degree of movement” detected by the normal movement detection. The degree of removed motion can be detected.
The mixing circuit 32 of the dot disturbance removal circuit 3 performs the filtering process when “the degree of movement is large and the degree of dot disturbance is small (when the value of the dot component removal movement detection signal MWD is large)” among the above detection results. In other cases, the mixing ratio of the filtered signal is increased.
With the above-described operation, it is possible to remove the dot interference generated when converting the composite signal into the component signal without blurring the image in the case of the motion signal.

Embodiment 2. FIG.
FIG. 7 shows a dot component removal motion detection circuit 4a used in the video signal processing apparatus according to Embodiment 2 of the present invention.
The dot component removal motion detection circuit 4a in FIG. 7 is generally the same as the dot component removal motion detection circuit 4 in FIG. 3, but differs in that difference determination circuits 46a and 46b are added.
The difference determination circuit 46a compares the output DV1 of the inter-frame difference calculation circuit 41 with a predetermined difference threshold value DT1, and outputs a 1-bit signal DB1 indicating the comparison result. Similarly, the difference determination circuit 46b compares the output DV2 of the inter-frame difference calculation circuit 42 with a predetermined difference threshold value DT2, and outputs a 1-bit signal DB2 indicating the comparison result.

The motion detection circuit 43 performs the same processing as described with reference to FIG. 4 on the 1-bit signals DB1 and DB2, and has a binary value indicating “with motion” or “without motion”, that is, 1 bit. The motion detection signal MN is output. The dot interference detection circuit 44 performs the same processing as described with reference to FIG. 5 on the 1-bit signals DB1 and DB2, and has a binary value indicating “with dot interference” or “without dot interference”. That is, a 1-bit dot disturbance detection signal BG is output.
Thus, in the present embodiment, the motion detection result and the dot disturbance detection result are represented by a 1-bit signal.

  FIG. 8 shows a synthesis circuit 45a according to the second embodiment of the present invention. The illustrated synthesis circuit 45 a includes a NOT circuit 453 and an AND circuit 454. The difference between the synthesis circuit 45a and the synthesis circuit 45 in the first embodiment is that the synthesis circuit 45a receives a multi-bit signal, whereas the synthesis circuit 45a receives a 1-bit signal and performs synthesis processing. . In other words, the motion detection signal MN is “1” in the case of a motion signal, but the dot interference detection signal BG is “1” in the case of dot interference, so the output of the NOT circuit 453 is “0” in the case of dot interference. " As a result, the output of the AND circuit 454 is “1” when “with motion” and “without dot interference”, and the output of the AND circuit 454 is “0” at other times. The output of the AND circuit 454 becomes the output of the synthesis circuit 45a, that is, the dot interference removal motion signal MWD.

FIG. 9 shows a dot disturbance removing circuit 3a used in the second embodiment of the present invention.
The illustrated dot interference removal circuit 3a is generally the same as the dot interference removal circuit 3 of FIG. 2, but includes a selection circuit 33 instead of the mixing circuit 32 of FIG.
When the dot component removal motion detection signal MWD is “1”, the selection circuit 33 selects a signal not to be filtered (1 frame delay signal VS1), and otherwise (the dot component removal motion detection signal MWD is “0”). ”), The filtered signal (the output of the filter 31) is selected.

  This is because the dot component removal motion detection signal MWD of Embodiment 1 is a multi-bit signal, whereas the dot component removal motion detection signal MWD of Embodiment 2 is a 1-bit signal. In the first embodiment, the mixing operation is performed by the mixing circuit 32 that receives the multi-bit dot component removal motion detection signal MWD. However, in this embodiment, the selection circuit that receives the 1-bit dot component removal motion detection signal MWD. 33, the selection operation is performed. However, the selection operation can be viewed as mixing at a mixing ratio of 1: 0 or 0: 1. Therefore, the selection circuit can also be viewed as a kind of mixing circuit.

  With the above configuration, the dot component removal motion detection signal MWD, which was handled as multi-bits in the first embodiment, can be handled as a 1-bit signal in the second embodiment, and the mixing circuit 32 is used in the first embodiment. However, it is not possible to mix the signal that has not been filtered and the signal that has been filtered at a rate corresponding to the degree of motion of the image, but there is an effect that the circuit scale can be reduced.

Embodiment 3 FIG.
FIG. 10 shows a dot component removal motion detection circuit 4b used in the video signal processing apparatus according to Embodiment 3 of the present invention.
The dot component removal motion detection circuit 4b shown in FIG. 10 is used in place of the dot component removal motion detection circuit 4 in FIG. 3, and the dot component removal motion detection circuit 4a in FIG. This is generally the same as the removal motion detection circuit 4 except that a synthesis circuit 45b is used instead of the synthesis circuit 45 of FIG.
In addition to the motion detection signal MN and the dot interference detection signal BG, the dot interference threshold BT is input to the synthesis circuit 45b.

FIG. 11 shows an example of the synthesis circuit 45b of FIG.
The illustrated synthesis circuit 45 b includes a comparison circuit 455 and a determination circuit 456. In the synthesis circuit 45a of FIG. 11, the dot disturbance detection signal BG is compared with the dot disturbance detection threshold value BT, and the value of the motion detection signal MN is controlled in the determination circuit 456 using the comparison result.
That is, the dot disturbance detection signal BG is compared with the dot disturbance detection threshold BT, and if the dot disturbance detection signal BG is larger than the dot disturbance detection threshold BT, the comparison result BB is set to “1”; “0”. When the 1-bit signal (dot interference detection signal converted to 1 bit) BB indicating the result of such comparison is “1”, the determination circuit 456 sets the motion detection signal MN to all “0”. When the dot disturbance detection signal BB converted to 1 bit is “0”, the motion detection signal MN is output as it is.
The output of the determination circuit 456 becomes the output of the synthesis circuit 45b, and hence the dot component removal motion signal MWD.

  With the above configuration, the signal handled as multi-bits in the synthesis circuit 45 of the first embodiment is partially handled as a 1-bit signal in the synthesis circuit 45b of the second embodiment (the dot disturbance detection signal is a 1-bit signal). Conversion into (), the operation of the synthesis circuit can be simplified and the circuit scale can be reduced. Further, the dot component removal motion signal MWD can be handled as multi-bits as in the first embodiment, and a signal that is not subjected to filter processing and a filter processing signal can be mixed at a rate corresponding to the degree of image motion. The transition between “movement” and “still” can be expressed smoothly.

Embodiment 4 FIG.
In the first to third embodiments, the dot disturbance removal motion detection circuit 4 detects the dot component removal motion detection signal MWD, and performs a filter operation in the dot disturbance removal circuit 3 when it is a stationary signal or a disturbance component. There is an effect of removing dot interference without blurring the image when it is a motion signal, but when the motion component is a frequency close to the color subcarrier, the difference between the motion detection result and the dot interference detection result is reduced. As a result, detection failure of the dot component removal motion signal occurs, and the output image tends to be blurred. By extracting and inputting only the color subcarrier band component from the inter-frame difference signals DV1 and DV2 to the dot interference detection circuit 44, it is possible to reduce the detection omission of the dot component removal motion signal. However, when the composite signal is converted into the component signal, if the signal format is also converted and scaled in the horizontal direction, this point needs to be taken into consideration when extracting the color subcarrier band.

FIG. 12 schematically shows an aspect ratio of an output image when an NTSC signal is converted into an HD format 1125i signal. As shown in the figure, an NTSC signal screen SE with an aspect ratio of 4: 3 is fitted as large as possible into an HD format screen (Wa: Hc = 16: 9) with an aspect ratio of 16: 9 while maintaining the aspect ratio. In general, the number of lines is converted to 1125 lines, and the horizontal direction is enlarged at the same ratio (scaling rate) to form an enlarged effective screen portion SF (Wb: Hc = 4: 3). Leave black strips BS on the left and right. The number of pixels SF of the effective screen portion after enlargement is 1440 pixels as shown in FIG.
Since the number of effective pixels of NTSC is 768 pixels, the scaling rate is 1440/768 = 1.875.
The color subcarrier frequency fsc 3.58 MHz in the NTSC signal is sampled at 4 fsc = 14.318 MHz. However, in the 1125i signal sampled at 74.25 MHz, the color subcarrier frequency is 9.9 MHz due to the above scaling rate. It has been converted. Therefore, when the NTSC signal is converted into a 1125i signal, a filter that extracts a 9.9 MHz band is used to extract the color carrier component from the converted signal.

FIG. 14 shows a dot component removal motion detection circuit 4c used in the video signal processing apparatus according to Embodiment 4 of the present invention.
The dot component removal motion detection circuit 4c shown in FIG. 14 is used in place of the dot component removal motion detection circuit 4 in FIG. 3, and is generally the same as the dot component removal motion detection circuit 4 in FIG. The difference is that carrier band extraction filters 47 and 48 as first and second carrier band extraction means are added.

The carrier band extraction filter 47 extracts the color subcarrier frequency component DB1 of the inter-frame difference signal DV1. The carrier band extraction filter 48 extracts the color subcarrier frequency component DB2 of the inter-frame difference signal DV2.
When horizontal scaling is not performed, the color subcarrier frequency fsc3.58 MHz may be extracted. However, in the case of a signal subjected to horizontal scaling for format conversion as described above, it is necessary to extract a band in which the color subcarrier frequency is converted. is there. Therefore, the first and second carrier band extraction filters 47 and 48 extract the component after conversion (in the above example, the component of 9.9 MHx) corresponding to the color subcarrier frequency component in the signal before scaling. It is configured as follows.

  The operation of the dot disturbance detection circuit 44 is the same as that described with reference to FIG. 3, but the input is the output of the carrier band extraction filters 47 and 48, that is, the carrier band component DB1 of the inter-frame difference DV1. And the carrier band component DB2 of the difference DV2 between the two frames.

Embodiment 5 FIG.
FIG. 15 shows a dot component removal motion detection circuit 4d used in the video signal processing apparatus of the fifth embodiment. The dot component removal motion detection circuit 4d shown is generally the same as the dot component removal motion detection circuit 4c of FIG. 14, but a plurality of carrier band extraction filters 47a to 47a used in place of the carrier band extraction filter 47 of FIG. 47n and selection circuit 49 constitute carrier band extraction means, and a plurality of carrier band extraction filters 48a to 48n used in place of carrier band extraction filter 48 and selection circuit 50 constitute carrier band extraction means. .

The dot component removal motion detection circuit 4c shown in FIG. 14 corresponds to the case where there is one type of signal format after conversion, but the dot component removal motion detection circuit 4d shown in FIG. Corresponds to multiple cases.
The selection circuit 49 and the selection circuit 50 are linked to each other, and each of the plurality of carrier band extraction filters 47a to 47n and 48a to 48n is selected according to the converted format indicated by the format conversion signal FC. Select.
With this configuration, it is possible to extract a carrier band component in the signal format after conversion, and it is possible to perform appropriate dot component removal for each signal format after conversion.

  As shown in FIG. 15, instead of the combination of a plurality of carrier band extraction filters and a selection circuit, a carrier band filter capable of switching tap coefficients is used as the carrier band extraction means, and the format conversion signal FC is used. The band component of the signal after conversion may be extracted by switching the tap coefficient according to the signal format after conversion shown.

Embodiment 6 FIG.
FIG. 16 shows a video signal processing apparatus according to the sixth embodiment.
The illustrated video signal processing apparatus is generally the same as the video signal processing apparatus of FIG. 1, but a carrier band extraction filter 6 and 1-frame delay circuits 7a and 7b are added, and the dot component removal motion detection circuit 4 of FIG. Instead, the difference is that a dot component removal motion detection circuit 4e is provided.

The carrier band extraction filter 6 extracts a color carrier band component from the 0 frame delay signal VS0 and outputs it as a carrier band signal VC0.
The color carrier band component referred to here is the color carrier frequency band component after the format conversion when the format conversion is performed.

The 1-frame delay circuit 7a delays the carrier band signal VC0 by one frame period and outputs a 1-frame delayed carrier band signal VC1.
The 1-frame delay circuit 7b delays the 1-frame delayed carrier band signal VC1 by one frame period and outputs a 2-frame delayed carrier band signal VC2.
The present invention is not limited to the configuration using the delay circuit as described above, and any component carrier band signal having a time difference in units of frames can be obtained.

The dot component removal motion detection circuit 4e is configured, for example, as shown in FIG.
The dot component removal motion detection circuit 4e shown in the figure is generally the same as the circuit shown in FIG. 3 except that a 1-frame difference calculation circuit 51 and a 2-frame difference calculation circuit 52 are added. The difference is that instead of the outputs of the 1-frame difference calculation circuit 41 and the 2-frame difference calculation circuit 42, the outputs of the 1-frame difference calculation circuit 51 and the 2-frame difference calculation circuit 52 are received.

The inter-frame difference calculation circuit 51 obtains the absolute value of the difference between the carrier band signal VC0 and the one-frame delayed carrier band signal VC1 and outputs it as the inter-frame difference signal DC1.
The difference calculation circuit 52 between two frames calculates the absolute value of the difference between the carrier band signal VC0 and the two frame delay carrier band signal VC2 and outputs it as the difference signal DC2 between the two frames.

  The operation of the dot disturbance detection circuit 44 is the same as that described with reference to FIG. 3, except that the input is obtained from the carrier band signal VC0 which is a dot disturbance component and the signals VC1 and VC2 obtained by delaying the carrier band signal VC0. They are different in that they are DC1 and DC2. Therefore, the dot disturbance detection can be performed accurately as described in the fourth embodiment.

  Instead of the carrier band extraction filter 6, a combination of a plurality of band extraction filters and a selection circuit may be used in the same manner as described with reference to FIG. In addition, a tap coefficient switchable filter may be used to switch the tap coefficient according to the signal format.

  1 input port, 2 output port, 3 dot interference elimination circuit, 4, 4a, 4b, 4c, 4d, 4e dot component elimination motion detection circuit, 5 1 frame delay circuit, 6 carrier band extraction filter, 31 filter, 32 mixing circuit , 33 selection circuit, 41 1 frame difference calculation circuit, 42 2 frame difference calculation circuit, 43 motion detection circuit, 44 dot disturbance detection circuit, 45 synthesis circuit, 46 difference determination circuit, 47, 48 carrier band extraction filter, 431 Maximum value circuit, 441 subtraction circuit, 442 dot disturbance detection circuit, 451 subtraction circuit, 452 limiter, 453 NOT circuit, 454 AND circuit, 455 comparison circuit, 456 determination circuit, 51 1 frame difference calculation circuit, 52 2 frame difference Calculation circuit.

Claims (7)

In a video signal processing apparatus that removes interference components of a component signal obtained by separating a luminance signal and a color signal from a composite signal,
A dot component that receives the first , second, and third component signals having a time difference in frame units between them, detects a motion signal excluding the dot interference component, and outputs a dot component-removed motion signal indicating the detection result Removal motion detection means;
When the first and second component signals and the dot component removal motion signal are input, and the dot component removal motion signal indicates that it is determined to be a stationary signal or an interference component, the first component signal a cormorant dot interference eliminating means Do to put a filter operation to remove the interfering components to one and the second component signal,
The dot component removal motion detection means includes:
A 1-frame difference calculation circuit for obtaining a 1-frame difference based on the first and second component signals;
A two-frame difference calculation circuit for obtaining a difference between two frames based on the first and third component signals;
First carrier band extraction means for extracting a carrier band component signal from the output of the inter-frame difference calculation circuit;
Second carrier band extraction means for extracting a carrier band component signal from the output of the difference calculation circuit between the two frames;
A motion detection circuit that outputs a motion detection signal indicating a motion detected based on the difference between the one frame and the difference between the two frames;
A dot disturbance detection circuit which receives the output signal of the first carrier band extraction means and the output signal of the second carrier band component extraction means and outputs a dot disturbance detection signal indicating dot disturbance;
A synthesis circuit that synthesizes the motion detection signal and the dot disturbance detection signal and outputs the dot component removal motion signal;
The motion detection circuit increases the value of the motion detection signal when at least one of the difference between the one frame and the difference between the two frames is large;
If the input signal is a motion signal, the dot disturbance detection circuit calculates the value of the dot disturbance detection signal if the input signal is a motion signal. If the dot interference is reduced, increase the value of the dot interference detection signal.
The video signal processor according to claim 1, wherein when the value of the dot disturbance detection signal is large, the synthesis circuit makes the magnitude of the dot component removal motion signal smaller than the motion detection signal . The dot disturbance detection circuit
A subtraction circuit for subtracting the carrier band signal of the difference between the two frames from the carrier band signal of the difference between the one frame to obtain a difference between the two,
And a limiter that outputs the difference as it is when the difference obtained by the subtraction circuit is a positive value or 0, and outputs 0 when the difference is a negative value. The video signal processing apparatus according to claim 1 . The motion detection circuit is
The video signal processing apparatus according to claim 1 , wherein a larger one of the difference between the one frame and the difference between the two frames is selected and output as a motion detection signal. The dot interference removing means is
A filter circuit that performs a filter operation for removing an interference component on the first and second component signals;
2. The video according to claim 1, further comprising a mixing circuit that mixes and outputs the output of the filter circuit and the first or second component signal at a mixing ratio corresponding to the dot interference removal motion signal. Signal processing device. The dot interference removing means is
A filter circuit that performs a filter operation for removing an interference component on the first and second component signals;
2. The video according to claim 1, further comprising: a selection circuit that selects and outputs either an output of a filter circuit or the first or second component signal in accordance with the dot interference removal motion signal. Signal processing device. In a video signal processing apparatus that removes interference components of a component signal obtained by separating a luminance signal and a color signal from a composite signal,
A first one-frame delay circuit that delays the input first component signal by one frame and outputs a second component signal;
A second one-frame delay circuit that delays the second component signal by one frame and outputs a third component signal;
The carrier band extracting means for extracting the color carrier band component of said first component signal, and outputs the first component carrier band signal,
The output of the carrier band extraction means is delayed to generate a second component carrier band signal delayed by one frame with respect to the first component carrier band signal, and further, with respect to the first component carrier band signal Bei give a delay means for generating a third component carrier band signal 2 frame delay,
The first, second, and third component signals and the first, second, and third component carrier band signals are input to detect a motion signal excluding the dot interference component, and to remove the dot component indicating the detection result Dot component removal motion detection means for outputting a motion signal;
When the first and second component signals and the dot component removal motion signal are input, and the dot component removal motion signal indicates that it is determined to be a stationary signal or an interference component, the first component signal Dot disturbance removing means for performing a filter operation for removing an interference component on the first and second component signals,
The dot component removal motion detection means includes:
A first inter-frame difference calculation circuit for obtaining a first inter-frame difference based on the first and second component signals;
A first inter-frame difference calculation circuit for obtaining a first inter-frame difference based on the first and third component signals;
A motion detection circuit that outputs a motion detection signal indicating a motion detected based on the first inter-frame difference and the first two-frame difference;
A second inter-frame difference calculating circuit for obtaining a second inter-frame difference based on the first and second component carrier band signals;
A second inter-frame difference calculation circuit for obtaining a second inter-frame difference based on the first and third component carrier band signals;
A dot disturbance detection circuit for outputting a dot disturbance detection signal indicating dot disturbance detected based on the second inter-frame difference and the second inter-frame difference; and
A synthesis circuit that synthesizes the motion detection signal and the dot disturbance detection signal and outputs the dot component removal motion signal;
The motion detection circuit increases a value of the motion detection signal when at least one of the first inter-frame difference and the first two-frame difference is large;
The dot disturbance detection circuit
It said by calculating the difference between the second 1 carrier band signal frame difference and the second 2 frame difference carrier band signal, reducing the value of if the input signal is a motion signal the dot interference detecting signal If it is dot interference, increase the value of the dot interference detection signal.
The combining circuit, when the value of the dot interference detecting signal is large, the size of the dots component removal motion signal, the motion detection signal Film image signal processing apparatus you characterized in that less than. 7. The video signal processing apparatus according to claim 6 , wherein the carrier wave band extracting means can switch a carrier wave frequency band to be extracted.

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