JP2005229568A - Motion vector detecting apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motion vector detecting apparatus having more reduced misdetection of a motion vector than before when the motion vector detecting apparatus is applied in particular to a video signal adopting the interlace system. <P>SOLUTION: In the motion vector detecting apparatus, an inter-frame motion vector V2 is outputted in place of an inter-field motion vector V1 when a motion is small and an inter-frame difference DFD 2 is smaller than an inter-field difference DFD 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a motion vector detection device, and in particular, can be applied to a case where a motion vector is detected from an interlace video signal. In the present invention, when the motion is small, when the inter-frame difference value is smaller than the inter-field difference value, the motion vector between the frames is output instead of the motion vector between the fields. It is possible to reduce false detection.

  Conventionally, in high-efficiency encoding processing of video signals, motion vectors are used to improve the efficiency of inter-frame encoding processing. In television signal format conversion, motion using motion vectors is used. By the correction, the jerky movement due to the conversion of the number of fields is corrected to a smooth movement.

  In such motion vector detection, a video signal is blocked into motion vector detection units (that is, macro blocks) of m pixels × n lines (m and n are integers), and a motion vector is detected for each block. For example, there are a pattern matching method disclosed in Japanese Patent Laid-Open Nos. 55-162683 and 55-162684, a gradient method disclosed in Japanese Patent Laid-Open No. 60-158786, a phase correlation method, and the like. It is made to be used.

  When a motion vector is detected from an interlaced video signal using such various motion vector detection methods, conventionally, a motion vector is detected between fields to prevent deterioration in detection accuracy when the amount of motion is large. Has been made. That is, the amount of motion between frames is twice that of between fields, so that the magnitude of the motion vector detected between frames is twice that of the motion vector detected between fields. When the amount of motion is large, the motion vector detection accuracy deteriorates.

  However, in the case of an interlaced video signal, the center of gravity of the video is shifted by ½ line in the vertical direction between the even field and the odd field, so that when the motion vector is detected between the fields, the center of gravity needs to be corrected in advance. However, when the center of gravity is corrected, the detection accuracy is deteriorated when the amount of motion is small. Specifically, even when the motion is “0” as in a still image, for example, the inter-field difference value cannot be the value “0” due to the centroid correction, which causes a detection error. Particularly in motion vector detection using the gradient method, by calculating a motion vector by calculation, the inter-field difference value does not become “0” even for a still image, and when there is an edge component of the image, A motion vector other than the value “0” is also detected in the still image.

As one method for solving this problem, a method of detecting a motion vector by converting an interlaced video signal into a progressive video signal can be considered. However, in the conversion process to the progressive method, the interpolation process is switched between the moving image and the still image, and the video signal of the previous field is used for the still image, but the moving image is the same as the center of gravity correction after all. Thus, even when the motion vector is detected after being converted into a progressive video signal, the motion vector is erroneously detected when the motion amount is small.
Japanese Unexamined Patent Publication No. 55-162683 Japanese Patent Laid-Open No. 55-162684 JP 60-158786 A

  The present invention has been made in consideration of the above points, and when detecting a motion vector with an interlaced video signal, the motion vector detection that can further reduce the erroneous detection of the motion vector as compared with the prior art. The device is to be proposed.

  In order to solve such a problem, the invention of claim 1 is applied to a motion vector detecting device for detecting a motion vector of an interlaced video signal to detect a motion vector between fields of the video signal and Inter-field motion vector detection means for outputting a motion vector, inter-frame motion vector detection means for detecting a motion vector between frames of a video signal and outputting a motion vector between frames, and an inter-frame motion vector and / or between fields A comparison unit that compares the motion vector with a predetermined criterion value and outputs a comparison result, and when a predetermined condition is satisfied based on the comparison result, the motion between frames is replaced with the motion vector between fields. Switching means for outputting a vector, and when the predetermined condition is satisfied, the motion between frames Motion vector between vector and or field so that it is smaller than the determination reference value.

  According to a second aspect of the present invention, the present invention is applied to a motion vector detection device for detecting a motion vector of an interlace video signal, detects a motion vector between fields of the video signal, and outputs a motion vector between fields. Inter-field motion vector detection means, inter-frame motion vector detection means for detecting a motion vector between frames of a video signal and outputting an inter-frame motion vector, and motion correction using an inter-field motion vector, Inter-field difference calculation means for detecting an inter-field difference value related to a motion vector, and inter-frame difference calculation means for detecting an inter-frame difference value related to a motion vector between frames by performing motion correction using the motion vector between frames. Compare the difference value between fields and the difference value between frames. And a switching means for outputting a motion vector between frames instead of a motion vector between fields when a predetermined condition is satisfied based on the comparison result, and satisfying the predetermined condition In this case, the difference value between frames is smaller than the difference value between fields.

  According to a third aspect of the present invention, the present invention is applied to a motion vector detecting device for detecting a motion vector of an interlace video signal, detects a motion vector between fields of the video signal, and outputs a motion vector between fields. Inter-field motion vector detection means, inter-frame motion vector detection means for detecting a motion vector between frames of a video signal and outputting an inter-frame motion vector, and inter-frame motion vector and / or inter-field motion vector are predetermined. A motion vector comparison unit that outputs a motion vector comparison result compared to the determination reference value of the field, and a field correction method that detects a difference value between fields related to a motion vector between fields by performing motion correction using a motion vector between fields. Motion compensation using the difference calculation means and motion vectors between frames A difference calculation means for detecting an inter-frame difference value related to a motion vector between frames, and a difference value comparison means for comparing a difference value between fields and an inter-frame difference value and outputting a difference value comparison result Switching means for outputting a motion vector between frames instead of a motion vector between fields when a predetermined condition is satisfied based on a comparison result of motion vectors and a comparison result of difference values. Is satisfied when the motion vector between frames and / or the motion vector between fields is smaller than the criterion value and the inter-frame difference value is smaller than the inter-field difference value.

  According to a fourth aspect of the present invention, there is provided a field delay circuit for applying to a motion vector detecting device for detecting a motion vector of an interlaced video signal, outputting the video signal with a delay of one field period, and a video signal. Delay using a frame delay circuit that outputs a signal delayed by one frame period, a field delay circuit, a switching circuit that selectively outputs an output signal of the frame delay circuit, a video signal, and an output signal of the switching circuit. When the motion vector detection circuit detects the vector and the motion vector detection circuit determines the magnitude of the motion vector, and the motion of the video signal is small, the motion vector detection circuit detects the motion vector between frames. A switching control circuit for controlling the switching circuit.

  According to a fifth aspect of the present invention, in the configuration of the fourth aspect, the switching control circuit controls the switching circuit in field units.

  According to a sixth aspect of the present invention, in the configuration of the fourth aspect, the switching control circuit controls the switching circuit in units of macroblocks.

  According to a seventh aspect of the present invention, in the configuration of the sixth aspect, the motion vector detecting circuit detects an initial deviation vector from the already detected motion vector, and the deviation vector detected using the initial deviation vector is initialized. The motion vector is detected by adding to the displacement vector, and the determination of the magnitude of the motion vector detected by the motion vector detection circuit by the switching control circuit is the determination of the initial displacement vector detected by the motion vector detection circuit. Like that.

  According to the configuration of the first aspect, the present invention is applied to a motion vector detection device that detects a motion vector of an interlace video signal, detects a motion vector between fields of the video signal, and outputs a motion vector between fields. Inter-field motion vector detection means, inter-frame motion vector detection means for detecting a motion vector between frames of a video signal and outputting an inter-frame motion vector, and inter-frame motion vector and / or inter-field motion vector are predetermined. Comparing means for outputting a comparison result compared to the determination reference value, and switching for outputting a motion vector between frames instead of a motion vector between fields when a predetermined condition is satisfied based on the comparison result And a motion vector between frames and / or between fields when a predetermined condition is satisfied. When the motion vector is smaller than the criterion value, the motion amount is small, and the motion vector between frames has a higher detection accuracy than the motion vector between fields. Instead, motion vectors between frames can be output, thereby reducing motion vector false detection.

  According to the second aspect of the present invention, the present invention is applied to a motion vector detection device for detecting a motion vector of an interlace video signal, detects a motion vector between fields of the video signal, and outputs a motion vector between fields. Inter-field motion vector detection means, inter-frame motion vector detection means for detecting a motion vector between frames of a video signal and outputting an inter-frame motion vector, and motion correction using an inter-field motion vector, The inter-field difference calculation means for detecting the inter-field difference value relating to the motion vector of the frame, and the inter-frame difference calculation for detecting the inter-frame difference value relating to the inter-frame motion vector by performing motion correction by the inter-frame motion vector. Comparison results between the field and the difference value between fields and the difference value between frames Comparing output means, and switching means for outputting a motion vector between frames instead of a motion vector between fields when a predetermined condition is satisfied based on the comparison result, the predetermined condition is satisfied When it is determined that the inter-frame motion vector is more reliable than the inter-field motion vector because the inter-frame difference value is smaller than the inter-field difference value. In addition, it is possible to output a motion vector between frames instead of a motion vector between fields, thereby reducing erroneous detection of motion vectors.

  According to the configuration of claim 3, the present invention is applied to a motion vector detecting device for detecting a motion vector of an interlaced video signal, and detects a motion vector between fields of the video signal and outputs a motion vector between fields. An inter-field motion vector detecting means, an inter-frame motion vector detecting means for detecting a motion vector between frames of a video signal and outputting an inter-frame motion vector, and an inter-frame motion vector and / or an inter-field motion vector. A motion vector comparing means for outputting a motion vector comparison result compared with a predetermined determination reference value, and a field for detecting a difference value between fields related to a motion vector between fields by performing motion correction with a motion vector between fields. Motion correction using the difference calculation means between frames and motion vectors between frames An inter-frame difference calculating means for detecting an inter-frame difference value relating to an inter-frame motion vector; and a differential value comparing means for comparing the inter-field difference value and the inter-frame difference value and outputting a difference value comparison result; Switching means for outputting a motion vector between frames instead of a motion vector between fields when a predetermined condition is satisfied based on a comparison result of motion vectors and a comparison result of difference values, When the condition is satisfied, the motion vector between frames and / or the motion vector between fields is smaller than the criterion value, and the inter-frame difference value is smaller than the inter-field difference value. The motion vector between frames has a higher detection accuracy than the motion vector between fields and the motion between fields. When it can be determined that the motion vector between frames is more reliable than the vector, the motion vector between frames can be output instead of the motion vector between fields. Detection can be reduced.

  According to the configuration of claim 4, the present invention is applied to a motion vector detecting device for detecting a motion vector of an interlaced video signal, a field delay circuit for delaying and outputting the video signal by a period of one field, and a video signal A motion vector using a frame delay circuit that outputs a delayed signal for a period of one frame, a field delay circuit, a switching circuit that selectively outputs an output signal of the frame delay circuit, a video signal, and an output signal of the switching circuit When the motion of the video signal is small by determining the size of the motion vector detected by the motion vector detection circuit and the motion vector detection circuit, the motion vector detection circuit switches to detect the motion vector between frames. A switching control circuit for controlling the circuit, the motion vector is determined by the motion vector determination. So as to reduce the erroneous detection of a motion vector by switching the detection, by a single motion vector detection circuit can be configured a motion vector detection apparatus, which makes it possible to simplify the entire configuration.

  According to the configuration of claim 5, in the configuration of claim 4, if the switching control circuit controls the switching circuit in units of fields, detection of motion vectors between fields and detection of motion vectors between frames in units of fields. And can be switched.

  According to the configuration of claim 6, in the configuration of claim 4, if the switching control circuit controls the switching circuit in units of macroblocks, detection of motion vectors between fields and motion vectors between frames in units of macroblocks. Can be switched.

  According to the configuration of claim 7, in the configuration of claim 6, the motion vector detection circuit detects an initial deviation vector from the already detected motion vector, and the detected deviation vector is detected using the initial deviation vector. The motion vector is detected by adding to the position vector, and the determination of the magnitude of the motion vector detected by the motion vector detection circuit by the switching control circuit seems to be the determination of the initial deviation vector detected by the motion vector detection circuit. In this case, when one motion vector detection circuit is used to switch between motion vector detection between fields and motion vector detection between frames in units of macroblocks, the motion vector detection accuracy can be improved. it can.

  According to the present invention, when a motion vector is detected with an interlaced video signal, it is possible to further reduce the erroneous detection of the motion vector as compared with the conventional case.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.

(1) Configuration of Embodiment FIG. 2 is a block diagram showing a motion vector detection apparatus according to Embodiment 1 of the present invention. The motion vector detection device 1 is applied to, for example, a format conversion device, a coding device based on MPEG (Moving Picture Experts Group), a noise reduction device, and the like, and uses a motion vector V from a luminance signal Y constituting an interlaced video signal. Is detected and output. In the detection of the motion vector, not only when the luminance signal Y is used, but the color difference signals RY and BY can also be used.

  In this motion vector detection device 1, the pre-filter 2 is a two-dimensional low-pass filter, which receives the luminance signal Y and suppresses high frequency components, thereby preventing erroneous detection of motion vectors due to noise. The pre-filter 2 performs so-called center-of-gravity correction processing by switching the tap coefficient in the vertical direction between the even field and the odd field. The pre-filter 2 is not limited to a low-pass filter, and a band-pass filter can be applied.

  The 1-field delay circuit 3 receives the luminance signal Y from the pre-filter 2 and outputs it after being delayed by a period of 1 field.

  The motion vector detection circuit 4 sequentially detects and outputs the motion vector V1 of the luminance signal Y output from the prefilter 2 based on the luminance signal Y1 output from the one-field delay circuit 3 by the gradient method. In this embodiment, macroblocks are sequentially set in the luminance signal Y output from the pre-filter 2, and the motion vector V1 is detected in units of macroblocks. This macroblock is composed of 8 pixels × 8 lines. It is designed to be set to size.

  Thus, in the motion vector detection device 1, the pre-filter 2, the 1-field delay circuit 3, and the motion vector detection circuit 4 detect the motion vector V1 between fields and output the motion vector V1 between fields. The detection means is configured.

  On the other hand, the pre-filter 5 is a two-dimensional low-pass filter, which receives the luminance signal Y and suppresses high frequency components, thereby preventing erroneous detection of motion vectors due to noise. The pre-filter 5 is not limited to a low-pass filter, and a band-pass filter can also be applied.

  The 1-frame delay circuit 6 receives the luminance signal Y from the pre-filter 5 and outputs it after being delayed by a period of 1 frame.

  The motion vector detection circuit 7 sequentially detects and outputs the motion vector V2 of the luminance signal Y output from the pre-filter 5 based on the luminance signal Y2 output from the one-frame delay circuit 6 by the gradient method. In this embodiment, the motion vector detection circuit 7 sets a macroblock in the same manner as the motion vector detection circuit 4 that detects a motion vector between fields, and detects a motion vector for each macroblock.

  Thus, in the motion vector detection device 1, the pre-filter 5, the one-frame delay circuit 6 and the motion vector detection circuit 7 detect the motion vector V2 between frames and output the motion vector V2 between frames. The detection means is configured.

  The comparison / switching circuit 8 outputs the inter-field motion vector V1 detected by the motion vector detection circuit 4 as the motion vector V of the luminance signal Y, and outputs the motion vector V when a predetermined condition is satisfied. , And instead of the motion vector V1 between fields, the motion vector V2 between frames detected by the motion vector detection circuit 7 is converted into a motion vector between fields and output.

  That is, as shown in FIG. 1, in the comparison / switching circuit 8, the memory circuit 11 records and holds the luminance signal Y1 output from the one-field delay circuit 3, and the held luminance signal Y1 corresponds to the macro block. Output in units of area of the size you want. In this process, the memory circuit 11 holds the address by shifting the read address by the amount of the motion vector V1 detected by the motion vector detection circuit 4 with respect to the write address used for writing the luminance signal Y1. The luminance signal Y1 is output, and the luminance signal Y1 held thereby is corrected by the motion vector V1 and output.

  The memory circuit 12 records and holds the luminance signal Y2 output from the one-frame delay circuit 6, and outputs the held luminance signal Y2 in units of areas corresponding to macroblocks. In this processing, the memory circuit 12 holds the address by shifting the read address by the amount of the motion vector V2 detected by the motion vector detection circuit 7 with respect to the write address used for writing the luminance signal Y2. The luminance signal Y2 is output, and the luminance signal Y2 held thereby is corrected by the motion vector V2 and output.

  The evaluation circuit 13 calculates the inter-field difference value DFD1 between the luminance signal output from the memory circuit 11 and the luminance signal Y of the current field in units of macroblocks of the luminance signal Y output from the prefilter 2. calculate. In addition, the evaluation circuit 13 performs the inter-frame difference value DFD2 between the luminance signal output from the memory circuit 12 and the luminance signal Y of the current field in units of macroblocks of the luminance signal Y output from the prefilter 5. Calculate In this embodiment, for the inter-field difference value DFD1 and inter-frame difference value DFD2, the difference value of the pixel value is calculated between the corresponding pixels, and the absolute value of the difference value is added for each macroblock. A sum of values is applied. Note that the sum of squares of such difference values may be applied to the inter-field difference value DFD1 and the inter-frame difference value DFD2. The evaluation circuit 13 outputs these calculation results to the vector value comparison / switching circuit 14. As a result, the memory circuit 11 and the evaluation circuit 13 constitute an inter-field difference calculation means for detecting the inter-field difference value DFD1 related to the inter-field motion vector V1 by performing motion correction with the inter-field motion vector V1. On the other hand, the memory circuit 12 and the evaluation circuit 13 constitute an inter-frame difference calculating means for detecting the inter-frame difference value DFD2 related to the inter-frame motion vector V2 by performing motion correction with the inter-frame motion vector V2. Has been made.

  The vector value comparison / switching circuit 14 replaces the inter-field motion vector V1 when a predetermined condition is satisfied based on the difference values DFD1, DFD2 and the inter-frame motion vector V2 thus detected. The motion vector V2 between frames is converted into a motion vector between fields and output, and the comparison / switching circuit 8 outputs the motion vector V output from the vector value comparison / switching circuit 14.

  Therefore, the vector value comparison / switching circuit 14 determines the amount of motion by comparing the inter-frame motion vector V2 output from the motion vector detection circuit 7 with a predetermined determination reference value α. As the determination reference value α, a value set by an operator's operation is applied, or a fixed value set in advance is applied.

  Here, when the magnitude of the motion vector V2 detected between the frames is smaller than the determination reference value α, the motion amount is small. In this case, the motion vector V1 detected between the fields is compared with the motion vector V1 detected between the fields. Thus, when the inter-frame motion vector V2 detected between frames is converted into a motion vector between fields, the motion vector can be detected with higher accuracy. Incidentally, even in a still image, the inter-field difference value does not become the value “0” by the gravity center correction, whereas the inter-frame difference value becomes a value “0” in the still image, and thereby, between the frames detected between the frames. The motion vector can be detected with higher accuracy by converting the motion vector V2 into a motion vector between fields.

  However, even when the motion vector V2 between frames is selected according to the magnitude of the motion vector V2, erroneous detection cannot always be prevented. Thereby, the vector value comparison / switching circuit 14 further compares the inter-field difference value DFD1 with the inter-frame difference value DFD2, and the magnitude of the motion vector V2 detected between frames is smaller than the determination reference value α. When the inter-frame difference value DFD2 is smaller than the inter-field difference value DFD1, the inter-frame motion vector V2 is converted into an inter-field motion vector instead of the inter-field motion vector V1 and output. Note that the conversion to the motion vector between the fields is simply performed by setting the value of the motion vector V2 to ½.

Note that the determination reference value α is provided for the X component and the Y component. In the determination based on the determination reference value α of the motion vectors V1 and V2, the respective components for the X component (VX) and the Y component (VY) are provided. The motion detected between frames on the condition that the magnitude relationship between the inter-field difference value DFD1 and the inter-frame difference value DFD2 is satisfied when the above criteria are satisfied for both components. The vector V2 is selected. In the determination based on the determination reference value α, the horizontal component VX and the vertical component VY of the motion vector V2 are processed by the relational expression MV = (VX ² + VY ² ) ^1/2 and compared with the determination reference value α. It may be.

  Thus, in the first embodiment, the evaluation circuit 13 corrects the motion using the inter-field motion vector V1 and detects the inter-field difference value DFD1 related to the inter-field motion vector V1. The inter-frame difference calculating means for detecting the inter-frame difference value DFD2 related to the inter-frame motion vector V2 by performing motion correction with the inter-frame motion vector V2, and the vector value comparison / switching circuit 14 A motion vector comparison unit that compares the vector V2 with a predetermined determination reference value α and outputs a motion vector comparison result, and compares the inter-field difference value DFD1 and the inter-frame difference value DFD2, and outputs the difference value comparison result. Difference value comparison means, and the comparison result of these motion vectors, the ratio of the difference values Based on the results, when a predetermined condition is satisfied, instead of the motion vector V1 between the fields it is adapted to constitute a switching means for outputting the motion vector V2 between frames.

(2) Operation of Embodiment In the above configuration, in the motion vector detecting device 1, the luminance signal Y of the interlaced video signal to be processed (FIG. 2) After the center of gravity in the odd field is corrected, the motion vector detection circuit 4 detects the motion vector V1 between the fields, and the motion vector V1 is output via the comparison / switching circuit 8, for example, for field interpolation or the like. Applied.

  As a result, in this motion vector detection device 1, by detecting a motion vector between fields, deterioration in detection accuracy when the amount of motion is large is prevented. However, by detecting motion vectors between fields in this way, and further correcting the center of gravity in advance, the motion vector detection accuracy decreases when the motion is small.

  For this reason, in the motion vector detection device 1, the motion vector detection circuit 7 detects the motion vector V2 between frames in parallel with the motion vector detection between the fields. Also, the luminance signals Y1 and Y2 are subjected to motion correction by the inter-field motion vector V1 and the inter-frame motion vector V2, and the inter-field difference value DFD1 and inter-frame difference value DFD2 are detected.

  In this motion vector detection apparatus 1, instead of the inter-field motion vector V1, the inter-frame motion is determined according to the inter-field difference value DFD1, inter-frame difference value DFD2, and inter-frame motion vector V2. The vector V2 is converted into a motion vector between fields and output.

  That is, a case where the motion is small is detected by comparing the motion vector V2 between the frames and the predetermined determination reference value α, and the motion vector V2 between the frames by comparing the inter-field difference value DFD1 and the inter-frame difference value DFD2. When the detected motion is small, the case where the inter-frame difference value DFD2 is smaller is detected. Accordingly, in this embodiment, when it is determined that the motion is small and the motion vector between frames is more reliable, the motion vector V2 between frames is replaced with the motion vector V1 between fields. As a result, a decrease in the accuracy of motion vector detection when the motion is small is effectively avoided, and the motion vector detection accuracy can be improved as compared with the conventional method.

(3) Effects of the embodiment According to the above configuration, when the motion is small and the inter-frame difference value is smaller than the inter-field difference value, an inter-frame motion vector is output instead of the inter-field motion vector. By doing so, it is possible to further reduce the erroneous detection of the motion vector as compared with the conventional case.

  In the motion vector detection apparatus according to this embodiment, when the motion is small in the vector value comparison / switching circuit 14 described above with reference to FIG. 1 based on the comparison result between the motion vector V2 between frames and a predetermined determination reference value α, Instead of the inter-field motion vector V1, the inter-frame motion vector V2 is converted into an inter-field motion vector and output. This embodiment has the same configuration as that of the motion vector detection apparatus 1 described above with respect to the first embodiment except that the configuration related to the selection criterion of the motion vector V2 is different.

  As a result, in this embodiment, although the detection accuracy is slightly lower than that of the motion vector detection device 1 according to the first embodiment, the configuration related to this criterion is simplified to simplify the overall configuration. ing.

  According to this embodiment, when the motion is small, by outputting a motion vector between frames instead of a motion vector between fields, it is possible to further reduce the erroneous detection of the motion vector as compared with the prior art.

  In the motion vector detection apparatus according to this embodiment, when the inter-frame difference value DFD2 is smaller than the inter-field difference value DFD1 in the vector value comparison / switching circuit 14 described above with reference to FIG. Thus, the motion vector V2 between frames is converted into a motion vector between fields and output. This embodiment has the same configuration as that of the motion vector detection apparatus 1 described above with respect to the first embodiment except that the configuration related to the selection criterion of the motion vector V2 is different.

  As a result, in this embodiment, although the detection accuracy is slightly lower than that of the motion vector detection device 1 according to the first embodiment, the configuration related to this criterion is simplified to simplify the overall configuration. ing.

  According to this embodiment, when the inter-frame difference value DFD2 is smaller than the inter-field difference value DFD1, the motion vector between the frames is output instead of the motion vector between the fields. Vector false detection can be reduced.

  In the first embodiment and the second embodiment described above, the case where the motion vector V2 between frames is determined by the predetermined determination reference value α to detect a case where the motion is small has been described. Instead of the motion vector V2, the magnitude of motion is determined by the motion vector V1 between fields.

  Even if the magnitude of motion is determined by the motion vector V1 between fields instead of the motion vector V2 between frames as in this embodiment, the same effect as in the above-described embodiment can be obtained.

  FIG. 3 is a block diagram showing a motion vector detection apparatus according to Embodiment 5 of the present invention. This motion vector detection device 21 detects and outputs a motion vector V from a luminance signal Y constituting an interlaced video signal. In the detection of the motion vector, not only when the luminance signal Y is used, but the color difference signals RY and BY can also be used.

  In this motion vector detection device 21, the pre-filters 22 and 23 are two-dimensional low-pass filters, which input the luminance signal Y and suppress high-frequency components, thereby preventing erroneous detection of motion vectors due to noise. . The pre-filters 22 and 23 execute so-called center-of-gravity correction processing by switching the tap coefficient in the vertical direction between the even field and the odd field.

  The pre-filter 24 is a similar two-dimensional low-pass filter that receives the luminance signal Y and suppresses high frequency components, thereby preventing erroneous detection of motion vectors due to noise. The pre-filter 24 can be omitted if necessary.

  The one-field delay circuit 25 receives the luminance signal Y from the pre-filter 23, and outputs it after delaying it for a period of one field. The 1-frame delay circuit 26 receives the luminance signal Y from the pre-filter 24, delays it for a period of 1 frame, and outputs it. Thus, the motion vector detection device 21 generates a luminance signal Y1 delayed by one field and a luminance signal Y2 delayed by one frame with respect to the luminance signal Y.

  The memory circuit 27 records and holds the luminance signal Y1 output from the one-field delay circuit 25, and selectively outputs the held luminance signal Y1 corresponding to the processing of the subsequent motion vector detection circuit 28. The memory circuit 28 records and holds the luminance signal Y1 output from the one-frame delay circuit 26, and selectively outputs the held luminance signal Y1 corresponding to the processing of the subsequent motion vector detection circuit 28.

  The switching circuit 30 selects the luminance signals Y 1 and Y 2 output from the memory circuits 27 and 28 under the control of the switching control circuit 31 and outputs them to the motion vector detection circuit 28.

  The motion vector detection circuit 28 sequentially detects and outputs the motion vector V2 of the luminance signal Y output from the prefilter 22 based on the luminance signal Y1 or Y2 output from the switching circuit 30 by the gradient method. For the detection of the motion vector, various methods other than the gradient method, such as a block matching method, can be widely applied. Accordingly, the motion vector detection circuit 28 detects and outputs a motion vector between fields or frames according to the setting of the switching circuit 30.

  The motion vector value setting circuit 32 inputs and outputs motion vectors V1 and V2 between fields and frames output from the motion vector detection circuit 28. At this time, when the motion vector output from the motion vector detection circuit 28 is a motion vector V2 between frames, the motion vector is converted into a motion vector V1 between fields and output. In this motion vector conversion, the motion vector V2 is simply halved.

  The vector value comparison circuit 33 averages the motion vectors in units of macro blocks output from the motion vector detection circuit 28 in units of fields. Further, the magnitude of the motion vector based on the average value is determined by the determination reference value α, and the determination result is output. In this process, when the motion vector output from the motion vector detection circuit 28 is a motion vector V2 between frames, the motion vector V1 between fields is converted into a motion vector V1 and determined by the determination reference value α.

When the motion vectors V1 and V2 output from the motion vector detection circuit 28 are equal to or less than the determination reference value α based on the determination result by the vector value comparison circuit 33, the switching control circuit 31 The switching circuit 30 is controlled so that a motion vector is detected between them. Here, the determination reference value α is provided for each of the X component and the Y component in the same manner as described above for the first embodiment, and the switching circuit 30 uses the motion vector detection circuit 28 for both the X component and the Y component. When the detected motion vectors V1 and V2 are smaller than the determination reference value α, the switching circuit 30 is controlled so that the motion vector is detected between frames. The magnitude of the motion vector is determined by processing the horizontal direction component VX and the vertical direction component VY of the motion vector with a relational expression of MV = (VX ² + VY ² ) ^1/2 and comparing it with the determination reference value α. It may be.

  Thus, in this embodiment, the high phase between successive fields of the video signal is effectively used, the magnitude of the motion vector detected in the immediately preceding field is determined based on the determination reference value, and the motion vector detection method for the subsequent field is determined. Switch between fields and frames. Further, the switching of motion vector detection between fields and frames is executed by switching the luminance signals Y1 and Y2 input to the motion vector detection circuit 28, thereby simplifying the overall configuration.

  That is, in the first to fourth embodiments described above, since it is necessary to provide motion vector detection circuits between fields and between frames, the configuration becomes complicated accordingly. However, if the motion vector detection is switched between the fields and between the frames by switching the luminance signals Y1 and Y2 input to the motion vector detection circuit 28 as in this embodiment, it is configured by one motion vector detection circuit. The entire configuration can be simplified accordingly.

  In this embodiment, the motion vector detection is switched between the fields and between the frames by switching the luminance signal input to the motion vector detection circuit as described above, and the motion vector detected in the immediately preceding field causes a small motion. By detecting a motion vector between frames in the following field, the overall configuration can be simplified, and erroneous detection of a motion vector can be further reduced as compared with the conventional case.

  The motion vector detection apparatus according to the sixth embodiment executes motion vector determination based on the determination reference value α described above with respect to the fifth embodiment and switching of the motion vector detection method in units of macroblocks. Accordingly, the motion vector detection device according to this embodiment sequentially determines the motion vectors output from the motion vector detection circuit 28 based on the determination reference value α in the vector value comparison circuit 33 of the motion vector detection device 21 in FIG. The determination result is output with a delay of one field period. In this determination processing, when the motion vector output from the motion vector detection circuit 28 is between frames, the size is corrected to ½ and the determination processing is executed. Further, the switching control circuit 31 controls the switching circuit 30 in units of macroblocks based on the determination result. The motion vector detection device according to the present embodiment is configured in the same manner as the motion vector detection device 21 according to the fifth embodiment except for determination of these motion vectors and switching of the motion vector detection method.

  In this embodiment, motion vector detection is switched between fields and between frames by switching the luminance signal input to the motion vector detection circuit, and the motion vector detected in the immediately preceding field is determined on a macroblock basis. Even if the detection of the motion vector is switched, the same effect as in the fifth embodiment can be obtained.

  In this embodiment, a motion vector is detected by the iterative gradient method, a motion vector predicted by this iterative gradient method is set as a determination target, and a motion vector determination and motion vector detection method is performed in units of macroblocks. Switch.

  That is, as shown in FIG. 4, the motion vector detection device 41 according to this embodiment detects a motion vector V by a motion vector detection circuit 48 based on an iterative gradient method. FIG. 4 is a block diagram showing the configuration of the motion vector detection device 41 in comparison with the motion vector detection device 21 of FIG. 3 only in the peripheral configuration of the motion vector detection circuit 48, and is prior to the memory circuits 27 and 28. The configuration is the same as that of the motion vector detection device 21.

  Here, the motion vector detection circuit 48 based on the iterative gradient method detects a motion vector in units of macroblocks, holds the detected motion vector V in the vector memory 51, and stores the detected vector stored in the vector memory 51. From the motion vector V, the predicted value of the motion vector related to the processing target macroblock is detected by the initial displacement vector selection circuit 52 and set to the initial displacement vector VV. In addition, the gradient method computing circuit 53 detects the displacement vector by the gradient method using the initial displacement vector VV, and the adding circuit 54 adds the displacement vector and the initial displacement vector VV to add the motion vector VV. Is detected.

  In this motion vector detection device 21, motion vector detection is performed by switching the motion vectors detected by the motion vector detection circuit 48 between fields and frames by switching the luminance signals Y1 and Y2 input to the motion vector detection circuit 48. When the detected motion vector is recorded in the vector memory 51, the circuit 48 converts it into a motion vector between fields and records it. Further, when the luminance signal Y2 output from the memory circuit 28 is processed to detect a motion vector between frames, when the motion vector held in the vector memory 51 is read and the initial deviation vector VV is selected, The initial deviation vector VV candidate vector is converted into a motion vector between frames and processed.

  The motion vector detection device 41 determines the initial deviation vector VV, which is a predicted value related to the processing target macroblock, by the motion vector value comparison circuit 33 based on the determination reference value α, and based on the determination result, the motion vector detection circuit 48 Switches input in units of macroblocks.

  In this embodiment, the magnitude of the motion vector is determined by determining the initial displacement vector by the iterative gradient method, and the detection of the motion vector is switched between the fields and between the frames, so that the initial value that is the predicted value of the motion vector Since the displacement vector is set as the determination target, the motion vector can be detected with higher accuracy than in the case of the sixth embodiment.

  In the motion vector detection devices according to the fifth to seventh embodiments described above, the case where the memory circuits 27 and 28 are provided subsequent to the delay circuits 25 and 26 has been described. If it can be secured by 26, the memory circuits 27 and 28 may be omitted.

  The present invention relates to a motion vector detection device, and can be applied to, for example, a format conversion device.

It is a block diagram which shows the comparison / switching circuit of the motion vector detection apparatus based on the Example of this invention. It is a block diagram which shows the motion vector detection apparatus which concerns on Example 1 of this invention. It is a block diagram which shows the motion vector detection apparatus which concerns on Example 5 of this invention. It is a block diagram which shows the motion vector detection apparatus which concerns on Example 7 of this invention.

Explanation of symbols

1, 21, 41 ... motion vector detection device, 3, 25 ... 1 field delay circuit, 4, 7, 28, 48 ... motion vector detection circuit, 6, 26 ... 1 frame delay circuit, 8 ... comparison / Switching circuit 11, 12, 27, 28 ... memory circuit, 13 ... evaluation circuit, 14 ... vector value comparison / switching circuit, 30 ... switching circuit, 31 ... switching control circuit, 33 ... vector value Comparison circuit

Claims (7)

In a motion vector detection device for detecting a motion vector of an interlaced video signal,
An inter-field motion vector detecting means for detecting a motion vector between fields of the video signal and outputting a motion vector between the fields;
Inter-frame motion vector detection means for detecting a motion vector between frames of the video signal and outputting a motion vector between frames;
A comparison means for comparing a motion vector between the frames and / or a motion vector between the fields with a predetermined determination reference value and outputting a comparison result;
Switching means for outputting a motion vector between the frames instead of the motion vector between the fields when a predetermined condition is satisfied based on the comparison result;
When the predetermined condition is satisfied,
A motion vector detection apparatus, wherein a motion vector between frames and / or a motion vector between fields is smaller than the determination reference value. In a motion vector detection device for detecting a motion vector of an interlaced video signal,
An inter-field motion vector detecting means for detecting a motion vector between fields of the video signal and outputting a motion vector between the fields;
Inter-frame motion vector detection means for detecting a motion vector between frames of the video signal and outputting a motion vector between frames;
A field difference calculation means for detecting a difference value between fields related to a motion vector between the fields by performing motion correction with the motion vector between the fields;
A frame-to-frame difference calculating means for detecting a frame-to-frame difference value related to the motion vector between the frames by performing motion correction with the frame-to-frame motion vector;
A comparing means for comparing the inter-field difference value and the inter-frame difference value and outputting a comparison result;
Switching means for outputting a motion vector between the frames instead of the motion vector between the fields when a predetermined condition is satisfied based on the comparison result;
When the predetermined condition is satisfied,
The motion vector detection device, wherein the inter-frame difference value is smaller than the inter-field difference value. In a motion vector detection device for detecting a motion vector of an interlaced video signal,
An inter-field motion vector detecting means for detecting a motion vector between fields of the video signal and outputting a motion vector between the fields;
Inter-frame motion vector detection means for detecting a motion vector between frames of the video signal and outputting a motion vector between frames;
A motion vector comparing means for comparing a motion vector between the frames and / or a motion vector between the fields with a predetermined criterion value, and outputting a motion vector comparison result;
A field difference calculation means for detecting a difference value between fields related to a motion vector between the fields by performing motion correction with the motion vector between the fields;
A frame-to-frame difference calculating means for detecting a frame-to-frame difference value related to the motion vector between the frames by performing motion correction with the frame-to-frame motion vector;
A difference value comparing means for comparing the inter-field difference value and the inter-frame difference value and outputting a difference value comparison result;
Switching means for outputting a motion vector between the frames instead of the motion vector between the fields when a predetermined condition is satisfied based on the comparison result of the motion vector and the comparison result of the difference value; ,
The case where the predetermined condition is satisfied is when the motion vector between the frames and / or the motion vector between the fields is smaller than the determination reference value and the inter-frame difference value is smaller than the inter-field difference value. A motion vector detection device characterized by being. In a motion vector detection device for detecting a motion vector of an interlaced video signal,
A field delay circuit for outputting the video signal with a delay of one field period;
A frame delay circuit for outputting the video signal with a delay of one frame period;
A switching circuit that selectively outputs an output signal of the field delay circuit and the frame delay circuit;
A motion vector detection circuit for detecting a motion vector using the video signal and an output signal of the switching circuit;
Switching for controlling the switching circuit so that the motion vector detection circuit detects a motion vector between frames when the motion of the video signal is small by determining the magnitude of the motion vector detected by the motion vector detection circuit. A motion vector detecting device comprising: a control circuit. The switching control circuit includes:
The motion vector detection device according to claim 4, wherein the switching circuit is controlled in a field unit. The switching control circuit includes:
The motion vector detection device according to claim 4, wherein the switching circuit is controlled in units of macroblocks. The motion vector detection circuit detects an initial deviation vector from the detected motion vector, and adds the deviation vector detected using the initial deviation vector to the initial deviation vector to detect the motion vector. And
The determination of the magnitude of the motion vector detected by the motion vector detection circuit by the switching control circuit is the determination of the initial deviation vector detected by the motion vector detection circuit. The motion vector detection device described.

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