JP2005051460A - Apparatus and method for processing video signal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide apparatus and a method for processing a video signal employed for e.g., a format converter that reduces image distortion due to erroneous detection of a motion vector in a motion interpolation processing or the like using the motion vector. <P>SOLUTION: The video signal processor sets the motion vector to a prescribed value when an inter-field difference or an inter-frame difference subjected to motion correction is smaller than an inter-field difference or an inter-frame difference not subjected to the motion correction and when the inter-field difference or the inter-frame difference subjected to motion correction is equal to or move than a criterion. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a video signal processing apparatus and a video signal processing method, and can be applied to, for example, a format conversion apparatus. The present invention determines the inter-field difference value or inter-frame difference value by motion correction when the inter-field difference value or inter-frame difference value by motion correction is smaller than the uncorrected inter-field difference value or inter-frame difference value. When the value is equal to or greater than the reference value, the motion vector is set to a predetermined value, so that image distortion due to erroneous detection of the motion vector can be reduced in motion interpolation processing using the motion vector.

  Conventionally, a variety of methods using motion vectors have been used in various processes of video signals.

  In such motion vector detection, a video signal is subdivided in units of macroblocks of M pixels × N lines (M and N are integers), and then a motion vector is detected for each macroblock. As this detection method, for example, a motion vector detection method by a pattern matching method is proposed in Japanese Patent Laid-Open Nos. 55-162683 and 55-162684, and Japanese Patent Laid-Open No. 60-158786. In the publications, a motion vector detection method using an iterative gradient method is proposed.

  In the format conversion, which is one of the video signal processing using such motion vectors, motion discontinuity is reduced by motion interpolation processing using the detected motion vectors. That is, in this process, the detected motion vector is corrected by the field interpolation ratio of the interpolation field, and the previous field and the current field are corrected by the corrected motion vector, respectively. In addition, inter-field interpolation is performed using the two fields subjected to the motion correction to generate an interpolation field.

  However, in such a motion vector, the motion vector may not be accurately detected between corresponding images. That is, as shown in FIGS. 4A and 4B, the foreground E by the stationary object exists in front of the background F as shown by the image of the previous field G2 and the image of the current field G1, and the background F is shown by the arrow A. When moving in the horizontal direction, the corresponding image does not exist in the previous field in the region R of the background R that has been hidden in the foreground E until then. As a result, for this region α, the motion vector cannot be accurately detected, and the motion vector is erroneously detected.

  As a result, there has been a problem that image distortion occurs in the conventional motion interpolation processing related to the conversion of the number of fields.

  That is, as shown in FIG. 5 in comparison with FIG. 4, when an interpolation field G0 having a field interpolation ratio γ is generated from the previous field G2 and the current field G1, the macroblock A1 belonging to the background F of the current field G1 When the motion vector V is detected and the area A2 in the previous field G2 corresponding to the macroblock A1 belongs to the background F, the macroblock A1 is macroscopically equivalent to the motion vector V detected in the macroblock A1. When the image of the block A1 is deviated and the motion correction is performed, the macroblock A1 subjected to the motion correction overlaps with the image of the area A2 belonging to the background F of the previous field G2.

  Thus, if the positions of the macroblock A1 and the area A2 in the current field G1 and the previous field G2 are connected by a straight line, the corresponding area A2 in the interpolation field G0 is also located on the straight line. Accordingly, in this case, the motion vector V is corrected by the interpolation ratio γ, and the macroblock A1 and the region A2 of the previous field G2 and the current field G1 are corrected to the position of the region A0 of the interpolation field G0. By performing inter-field interpolation processing on the corrected image data, the image data of the interpolation field G0 can be generated correctly.

  In the macroblock D1 belonging to the foreground E of the current field G1, the motion vector V is detected by the value 0 because it is stationary, and the region D2 corresponding to the previous field G2 based on the motion vector V also changes to the foreground E. Will belong. Thereby, also in this case, the image data of the interpolation field G0 can be generated correctly by performing the motion correction by the motion vector V and performing the inter-field interpolation processing.

On the other hand, even if the macroblocks B1 and C1 belong to the background F in the current field G1, if the corresponding regions B2 and C2 are hidden in the foreground E in the previous field G2, each of the macroblocks B1 and C1 is more than the previous field G2. The image data of the areas B2 and C2 corresponding to the macroblocks B1 and C1 cannot be acquired appropriately. In this case, if a motion vector is erroneously detected, and if motion compensation is performed using this motion vector and inter-field interpolation processing is performed, image distortion will occur.
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 a video signal processing apparatus and video signal processing capable of reducing image distortion due to erroneous detection of motion vectors in motion interpolation processing using motion vectors, etc. We are going to propose a method.

  In order to solve such a problem, in the first aspect of the present invention, the present invention is applied to a video signal processing apparatus that processes a video signal using a motion vector, and motion correction is performed on consecutive fields or frames by the amount of the motion vector detected from the video signal. Then, by detecting the inter-field difference value or inter-frame difference value, the inter-field difference value or inter-frame difference value by motion correction is detected, and the inter-field difference value or By detecting the inter-frame difference value, the inter-field difference value or inter-frame difference value without motion correction is detected, and the inter-field difference value or inter-frame difference value by motion correction and the inter-field difference without motion correction are detected. Set the motion vector to a predetermined value by comparing with the value or the difference value between frames, Even if the inter-field difference value or inter-frame difference value by the motion correction is smaller than the non-motion-corrected inter-field difference value or the inter-frame difference value, the inter-field difference value or the inter-frame difference value by the motion correction is not less than the criterion value. In this case, the motion vector is set to a predetermined value.

  According to the invention of claim 2, in the configuration of claim 1, the comparison between the inter-field difference value or inter-frame difference value obtained by motion correction and the inter-field difference value or inter-frame difference value that is not subjected to motion correction is constant. This is executed by comparing the absolute value sum of the inter-field difference or inter-frame difference due to motion correction in the region with the inter-field difference or inter-frame difference absolute value sum of the constant region that is not motion corrected.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, the predetermined value is a value of zero.

  According to a fourth aspect of the present invention, in the configuration of the first, second, or third aspect, after a field or frame is motion-corrected by a motion vector, interpolation is performed between fields or between frames. The number of fields or frames is converted by creating fields or interpolated frames.

  According to a fifth aspect of the present invention, the present invention is applied to a video signal processing method for processing a video signal using a motion vector, and motion correction is performed on a continuous field or frame by the amount of a motion vector detected from the video signal. By detecting an inter-frame difference value or an inter-frame difference value, an inter-field difference value or an inter-frame difference value by motion correction is detected, and an inter-field difference value or an inter-frame difference is detected without motion correction of consecutive fields or frames. By detecting the value, the inter-field difference value or inter-frame difference value that is not motion-corrected is detected, and the inter-field difference value or inter-frame difference value that is not motion-corrected, and the inter-field difference value or frame that is not motion-corrected The motion vector is set to a predetermined value by comparison with the difference value between Even if the field-to-field difference value or the frame-to-frame difference value is smaller than the field-to-field difference value or the frame-to-frame difference value that has not been subjected to motion correction, Set the vector to a predetermined value.

  According to the configuration of the first aspect, the present invention is applied to a video signal processing apparatus, and motion correction is performed on a continuous field or frame by a motion vector detected from the video signal to detect an inter-field difference value or an inter-frame difference value. Therefore, motion compensation is not performed by detecting inter-field difference values or inter-frame difference values by motion compensation, and detecting inter-field difference values or inter-frame difference values without motion compensation of consecutive fields or frames. When detecting an inter-field difference value or an inter-frame difference value, the inter-field difference value or inter-frame difference value by the motion correction and the inter-field difference value or the inter-frame difference value that are not subjected to motion correction are respectively motion correction. Between the fields involved in processing and It will show the degree of difference between the beam. Accordingly, if the motion vector is set to a predetermined value by comparing the inter-field difference value or inter-frame difference value obtained by motion correction with the inter-field difference value or inter-frame value difference value that is not subjected to motion correction, the difference is reduced. The video signal can be processed by the side motion vector, and image distortion and the like can be prevented accordingly. However, even in such processing, if the inter-field difference value or inter-frame difference value due to motion correction rises above a certain value, there is no movement between these fields or frames, for example, it has been hidden in the foreground until then. It can be determined that this is the case of an area appearing as a result, or a scene change or the like. As a result, even when the inter-field difference value or inter-frame difference value obtained by motion correction is smaller than the inter-field difference value or inter-frame difference value that has not undergone motion correction, the inter-field difference value or inter-frame difference value obtained by motion correction is determined as the criterion value. In the above case, if the motion vector is set to a predetermined value, it is possible to reduce the image distortion caused by the motion correction and processing in the area that has been hidden in the foreground until then, and in the case of a scene change or the like. Thus, image distortion due to erroneous detection of motion vectors can be reduced in motion interpolation processing using motion vectors.

  According to the configuration of claim 2, in the configuration of claim 1, the comparison between the inter-field difference value or inter-frame difference value obtained by motion correction and the inter-field difference value or inter-frame difference value that is not motion-corrected is performed in a certain region. If it is executed by comparing the absolute value sum of the inter-field difference or the inter-frame difference due to the motion correction and the inter-field difference or the inter-frame difference uncorrected motion in a certain region, it is simple and sure, The inter-field difference value or inter-frame difference value obtained by motion correction can be compared with the inter-field difference value or inter-frame difference value that has not undergone motion correction.

  Further, according to the configuration of claim 3, if the predetermined value is set to 0 in the configuration of claim 1 or claim 2, processing can be switched between a moving image and a still image.

  According to the configuration of claim 4, in the configuration of claim 1, 2, or 3, the field or frame is corrected for motion by the motion vector, and then interpolated between the fields or frames to interpolate the field. Alternatively, if the number of fields or the number of frames is converted by creating an interpolation frame, it can be applied to the conversion of the number of fields to reduce image distortion due to erroneous detection of motion vectors.

  According to the configuration of claim 5, the present invention is applied to a video signal processing method, and motion correction is performed on a continuous field or frame by the amount of a motion vector detected from the video signal, and an inter-field difference value or an inter-frame difference value is obtained. By detecting the difference value between fields or the difference value between frames by the motion correction, the motion correction is performed by detecting the difference value between fields or the difference value between frames without correcting the motion of the continuous field or frame. When detecting the inter-field difference value or the inter-frame difference value, the inter-field difference value or the inter-frame difference value by the motion correction, and the inter-field difference value or the inter-frame difference value not subjected to the motion correction are respectively Whether the motion is corrected or not, the inter-field or It will show the degree of difference between frames. As a result, if the motion vector is set to a predetermined value by comparing the inter-field difference value or inter-frame difference value obtained by motion compensation with the inter-field difference value or inter-frame difference value that is not motion compensated, the difference becomes smaller. Thus, the video signal can be processed with the motion vector, and image distortion or the like can be prevented accordingly. However, even in such processing, when the difference value between fields or the difference value between frames due to motion correction rises above a certain value, there is no movement between these fields or frames, for example, it is hidden in the foreground until then. It can be determined that this is a case of an area that appears and a scene change or the like. As a result, even when the inter-field difference value or inter-frame difference value obtained by motion correction is smaller than the inter-field difference value or inter-frame difference value that has not undergone motion correction, the inter-field difference value or inter-frame difference value obtained by motion correction is determined as the criterion value. In the above case, if the motion vector is set to a predetermined value, it is possible to reduce the image distortion caused by the motion correction and processing in the area that has been hidden in the foreground until then, and in the case of a scene change or the like. Thus, image distortion due to erroneous detection of motion vectors can be reduced in motion interpolation processing using motion vectors.

  According to the present invention, it is possible to reduce image distortion caused by erroneous detection of a motion vector in motion interpolation processing using a motion vector.

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

(1) Configuration of Embodiment FIG. 1 is a block diagram showing a video signal processing apparatus according to an embodiment of the present invention. The video signal processing apparatus 1 converts the number of fields of the video signal S1 by inter-field interpolation processing by motion interpolation, and converts the format to the video signal S1.

  That is, in this video signal processing apparatus 1, the pre-filter 2 is a two-dimensional low-pass filter, which inputs the luminance signal component of the video signal S1 and suppresses the high-frequency component, thereby erroneously detecting a motion vector due to noise. To prevent. The prefilter 2 can be omitted.

  A one-field delay circuit (1FD) 3 selectively inputs a luminance signal component from the pre-filter 2 and outputs it after delaying it by a period of one field. As a result, the 1-field delay circuit 3 generates the previous-field video signal S3 for the current-field video signal S2 output from the pre-filter 2.

  The motion vector detection circuit 4 sequentially sets macroblocks in the video signal S2 output from the prefilter 2 and detects a motion vector with respect to the output signal of the one-field delay circuit 3, thereby detecting the current field. A motion vector is detected with reference. When the motion vector detection circuit 4 detects a motion vector between frames, a 1-frame delay circuit is applied instead of the 1-field delay circuit 3, and the video signal S2 is delayed by 1 frame. As a motion vector detection method, various detection methods such as a block matching method, an iterative gradient method, and a phase correlation method can be widely applied. Further, a motion vector may be detected for each pixel. In this embodiment, the macroblock is set to a size of 8 pixels × 8 lines.

  The motion vector detection circuit 4 corrects the motion vector by multiplying the motion vector detected in this way by interpolation ratios γ and 1-γ related to the interpolation field, and moves from the current field to the interpolation field. A vector Va and a motion vector Vb from the previous field to the interpolation field are generated and output.

  The delay circuit (D) 5 delays the video signal S2 of the current field output from the prefilter 2 for a predetermined time and outputs it. The deviation circuit 6 temporarily records the video signal output from the delay circuit 5 in a built-in memory, and outputs it at a timing according to the motion vector Va from the current field to the interpolation field. As a result, the displacement circuit 6 deviates the position of the image constituting the current field in accordance with the motion vector detected by the motion vector detection circuit 4 and outputs it. Hereinafter, the video signal output from the displacement circuit 6 is referred to as a motion correction video signal SC based on the current field.

  The delay circuit (D) 7 delays the video signal S2 in the current field and outputs the video signal SE so that the timing coincides with the video signal SC for motion correction in the current field. Hereinafter, this video signal SE is referred to as a video signal not subjected to motion correction in the current field.

  The delay circuit (D) 8 delays the video signal S3 of the previous field output from the 1-field delay circuit 3 by a predetermined time and outputs it. The displacement circuit 9 temporarily records the video signal output from the delay circuit 8 in a built-in memory, and outputs the video signal at a timing according to the motion vector Vb from the previous field to the interpolation field. As a result, the displacement circuit 9 deviates the position of the image data constituting the previous field in accordance with the motion vector detected by the motion vector detection circuit 4 and outputs it. Hereinafter, the video signal output from the displacement circuit 9 is referred to as a motion correction video signal SD based on the previous field.

  The delay circuit (D) 10 outputs the video signal SF by delaying the video signal S3 in the previous field so that the timing coincides with the video signal SD for motion correction in the previous field. Hereinafter, this video signal SE is referred to as a video signal not subjected to motion correction by the previous field.

  Thus, in the video signal processing apparatus 1, the video signals SD and SC obtained by motion-correcting the video signals SF and SE of the previous field and the current field, and the video signals SF and SE of the previous field and the current field so as to correspond to the interpolation field. Has been made to generate.

  The motion determination circuit 11 appropriately corrects and outputs the motion vectors Va and Vb output from the motion vector detection circuit 4 using these video signals SE to SF. That is, the motion determination circuit 11 detects the inter-field difference value between the video signals SF and SE that are not motion-corrected in the previous field and the current field, and between the video signals SD and SC by the motion correction in the previous field and the current field. Detect the difference value between fields.

  In this embodiment, the absolute value sum of inter-field differences in a predetermined block is applied to the detection of these inter-field difference values. That is, the motion determination circuit 11 sequentially calculates a difference value between corresponding pixels between the video signals SF and SE that are not motion-corrected, adds the absolute value of the difference value in units of a predetermined block, and thereby does not perform motion correction. The inter-field difference value FD is detected. Similarly, a difference value is sequentially calculated between corresponding pixels between the video signals SD and SC by the motion correction, and the absolute value of the difference value is added in units of a predetermined block, which is detected by the motion vector detection circuit 4. An inter-field difference value DFD by motion correction when motion correction is performed using a motion vector is detected. In addition, a block smaller than the macro block which is a motion vector detection unit is applied to the block used for the addition. In this embodiment, the macro block is finely divided, for example, one block is set to 4 pixels × 2 lines. Note that such addition processing may be omitted, and the subsequent processing may be executed in units of pixels.

  The motion determination circuit 11 determines the inter-field difference value FD that has not been subjected to motion correction and the inter-field difference value DFD that have been detected as described above, based on the configuration shown in FIG.

  That is, in the motion determination circuit 11 shown in FIG. 2, the comparison circuit 11A inputs and compares the inter-field difference values FD and DFD to the comparison circuit 11A, and outputs the comparison result to the switch circuit 11C.

  The comparison circuit 11B determines the inter-field difference value DFD by motion correction based on the determination reference value β, and outputs the determination result.

  The switch circuit 11C receives the motion vector Va from the current field to the interpolation field output from the motion vector detection circuit 4 and the motion vector Vb of the interpolation field from the previous field at one contact point, and receives a motion vector having a value of 0 (see FIG. 2 is indicated by the ground of the contact of the switch circuit 11C) at the other contact, and these contact inputs are selectively output according to the determination results of the comparison circuits 11A and 11B.

  In the selection output based on the determination result, the switch circuit 11C selects and outputs a motion vector having a value of 0 when the inter-field difference value FD that has not undergone motion correction is smaller than the inter-field difference value DFD obtained by motion correction. When the inter-field difference value FD without motion correction is equal to or greater than the inter-field difference value DFD by motion correction, the motion vector Va from the current field to the interpolation field and the motion vector Vb of the interpolation field from the previous field are selectively output. .

  That is, as shown in FIG. 3 in comparison with FIG. 5, among the inter-field difference values FD and DFD detected in this way, the inter-field difference value FD not subjected to motion correction corresponds to the interpolation field G0. When the region C0 to be operated is the regions B01 and B02 in which no movement occurs in the current field G1 and the previous field G2, that is, when the corresponding regions B01 and B02 in the current field G1 and the previous field G2 match, 0. On the other hand, when the region C0 is a region corresponding to a region having motion in the current field G1 and the previous field G2, the inter-field difference value FD that has not undergone motion correction has a large value, which When the correction is not performed, the degree of difference between the fields related to the processing is indicated.

  On the other hand, in the inter-field difference value DFD by motion correction, when the area A2 in the previous field G2 moves to the area A1 in the current field G1, and the motion is corrected by the motion vector V related to this movement. The value is almost 0. On the other hand, if the value of the motion vector related to the motion correction is different from the correct value, the inter-field difference value DFD by the motion correction becomes large. It indicates the degree of difference between such fields. In the example of FIG. 3, the difference between these two fields is DFD = Σ | A1-A2 | and FD = Σ | B01−B02 | for the region C0 of the interpolation field G0.

  As a result, when the inter-field difference value FD without motion correction is smaller than the inter-field difference value DFD by motion correction, a motion vector of value 0 is selected and output, and the inter-field difference value FD without motion correction is selected by motion correction. In the case of the inter-field difference value DFD or more, by selecting and outputting the motion vector Va from the current field to the interpolation field and the motion vector Vb of the interpolation field from the previous field, the motion vector detection circuit 4 The motion vector detected in step S3 can be output, and for a region having no motion, the motion vector detected by the motion vector detection circuit 4 can be corrected to a value 0 and output, thereby correcting erroneous detection of the motion vector. .

  However, even when the motion vector is corrected in this way, for example, if there is an area that has been hidden in the foreground until then, and if a scene change occurs, there is no corresponding area between fields. In some cases, the inter-field difference value DFD by the motion correction is smaller than the inter-field difference value FD that is not subjected to motion correction.

  That is, when the motion is uniform and the motion vector is normally detected, the motion vector detected with reference to the current field is uniform, and the inter-field difference value DFD by motion correction is also small.

  However, in a region where the motion vector is not correctly detected, the inter-field difference value DFD due to motion correction becomes large. In such a case, if the image is not a still image, the inter-field difference value FD without motion correction also becomes large, and the field due to motion correction. The inter-field difference value DFD becomes smaller than the inter-field difference value FD that is not subjected to motion correction, and a motion vector detected by the motion vector detection circuit 4 is selected. In this case, when the motion correction is performed using the motion vector and the interpolation processing is performed, as described above with reference to FIG. 5, image distortion occurs, and the image distortion is smaller when the motion correction is not performed.

  Thereby, in the motion determination circuit 11, when the value of the inter-field difference value DFD by the motion correction is equal to or larger than the determination reference value β, the inter-field difference value DFD by the motion correction is smaller than the inter-field difference value FD that is not motion-corrected. Even so, the motion vector is set to a predetermined value based on the value 0 and output to reduce image distortion. Here, in this video signal processing apparatus 1, the determination reference value β can be set by an operator's operation. By checking the processing result and setting the determination reference value β, the video signal to be processed is set. Accordingly, the determination reference value β is appropriately set so that image distortion can be reduced as compared with the conventional case.

  As a result, the video signal processing apparatus 1 executes motion interpolation processing using the motion vectors Va1 and Vb1 output from the motion determination circuit 11. That is, in the video signal processing apparatus 1, the one-field delay circuit (1FD) 14 delays the video signal S1 by a period of one field, thereby generating and outputting the video signal of the previous field.

  The delay circuit 15 temporarily records the video signal of the previous field in the built-in memory, and then outputs the video signal of the previous field by timing according to the corresponding motion vector Vb1 output from the motion determination circuit 11. Is output after motion correction.

  The delay circuit 16 temporarily records the video signal S1 in the built-in memory, and then outputs the video signal S1 at a timing according to the corresponding motion vector Va1 output from the motion determination circuit 11, thereby correcting the motion of the video signal in the current field. Output.

  The motion interpolation circuit 17 interpolates the video signal S1 output from the delay circuits 15 and 16 and outputs a video signal S0 having a changed number of fields.

(2) Operation of Embodiment In the above configuration, in this video signal processing apparatus 1, the video signal of the current field, which is the video signal S1 to be processed, is delayed by one field by the one-field delay circuit 14, and the video signal of the previous field Are generated, and these video signals are subjected to inter-field interpolation processing by the motion interpolation circuit 17, whereby the number of fields of the video signal S1 is converted. In this processing, in the video signal processing apparatus 1, the video signals of the previous field and the current field are subjected to motion correction by the delay circuits 15 and 16, respectively, and subjected to interpolation processing, thereby smoothing the motion in consecutive fields. Can do.

  In the video signal processing apparatus 1, the luminance signal component of the video signal S1 is delayed by one field by the one-field delay circuit 3 to generate a video signal S3 of the previous field. The video signal S3 of the previous field and the current field The video signal S2 is processed by the motion vector detection circuit 4 to detect a motion vector based on the current field. This motion vector is corrected by the interpolation ratios γ and 1-γ of the interpolation field, and motion vectors Va and Vb for motion correction of the previous field and the current field in the delay circuits 15 and 16 are generated, respectively.

  In the video signal processing apparatus 1, the motion signals Va and Vb for motion correction correct the motion of the video signals S3 and S2 of the previous field and the current field by the displacement circuits 6 and 9, respectively, and the video signals of the previous field and the current field This is input to the motion determination circuit 11 together with S3 and S2, and the motion determination circuit 11 detects an inter-field difference value DFD by motion correction and an inter-field difference value FD without motion correction from these video signals. In the video signal processing apparatus 1, motion vector detection is performed so that the inter-field difference value FD is reduced by comparing the inter-field difference value DFD obtained by the motion correction with the inter-field difference value FD that is not subjected to motion correction. The motion vectors Va and Vb for motion correction of the previous field and the current field generated by the circuit 4 are corrected directly to the value 0 and output to the delay circuits 15 and 16.

  That is, when the inter-field difference value DFD by motion correction is smaller, the motion vectors Va and Vb for motion correction of the previous field and the current field generated by the motion vector detection circuit 4 are output to the delay circuits 15 and 16. On the other hand, if the inter-field difference value FD without motion correction is smaller, the motion vector is corrected to a value of 0 and output to the delay circuits 15 and 16, thereby corresponding to moving images and still images, respectively. The number of fields of the video signal S1 is converted by inter-field interpolation processing.

  In this video signal processing apparatus 1, when the motion vectors Va and Vb are processed in this way, if the inter-field difference value DFD by motion correction is larger than a predetermined value β, the inter-field difference value DFD is corrected for motion correction. Even if it is smaller than the inter-field difference value FD, the detected motion vectors Va and Vb are set to a value of 0 and output to the delay circuits 15 and 16, thereby, for example, an area that has been hidden in the background until now, For a scene such as scene change, an interpolation field is generated by inter-field interpolation without motion correction. As a result, the video signal processing apparatus 1 can reduce image distortion as compared with the conventional art.

(3) Effects of the embodiment According to the above configuration, when the inter-field difference value by motion correction is smaller than the inter-field difference value not subjected to motion correction, the inter-field difference value by motion correction is greater than or equal to the determination reference value. By setting the motion vector to a predetermined value, image distortion due to erroneous detection of the motion vector can be reduced in motion interpolation processing using the motion vector.

  At this time, these inter-field difference values are detected by the sum of absolute values of the inter-field differences, so that these inter-field difference values can be detected and compared easily and reliably.

  In addition, since the predetermined value of the motion vector to be set when the inter-field difference value by the motion correction is equal to or greater than the determination reference value, the process can be switched between the moving image and the still image.

  In addition, after correcting for motion using the motion vector corrected in this way, an inter-field interpolation process is performed to create an interpolation field. Distortion can be reduced.

  In the above-described embodiment, the case where the inter-field difference value is detected by the absolute value sum of the inter-field difference is described. However, the present invention is not limited to this, and for example, the inter-field difference value is calculated by the square sum of the inter-field difference. For example, various detection methods can be widely applied.

  In the above-described embodiments, the case where the present invention is applied to the format conversion related to the conversion of the number of fields has been described. However, the present invention is not limited to this, and the present invention is also applicable to the format conversion related to the conversion processing of the number of frames. Furthermore, motion vectors such as inter-field interpolation processing in interlaced and non-interlace format conversion, noise reduction processing using motion vectors, and field interpolated image generation processing in a high-efficiency encoding device can be used. The present invention can be widely applied to the interpolation processing used.

  The present invention relates to a video signal processing apparatus and a video signal processing method, and can be applied to, for example, a format conversion apparatus.

1 is a block diagram illustrating a video signal processing apparatus according to Embodiment 1 of the present invention. It is a block diagram which shows the motion determination circuit of the video signal processing apparatus of FIG. 3 is a chart for explaining the operation of the motion determination circuit of FIG. 2. It is a top view with which it uses for description of the misdetection of a motion vector. It is an approximate line figure used for explanation of image distortion.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Video signal processing apparatus, 3, 14 ... 1 field delay circuit, 4 ... Motion vector detection circuit, 5, 7, 8, 10, 15, 16 ... Delay circuit, 6, 9 ... Deviation circuit , 11... Motion determination circuit, 17... Motion interpolation circuit

Claims (5)

In a video signal processing apparatus that processes a video signal by a motion vector,
By correcting the motion of consecutive fields or frames by the motion vector detected from the video signal and detecting the inter-field difference value or inter-frame difference value, the inter-field difference value or inter-frame difference value by motion correction is detected. Detect
By detecting the inter-field difference value or inter-frame difference value without correcting the motion of the continuous field or frame, the inter-field difference value or the inter-frame difference value without motion correction is detected,
By comparing the inter-field difference value or inter-frame difference value by the motion correction and the inter-field difference value or inter-frame difference value not subjected to the motion correction, the motion vector is set to a predetermined value,
Even if the inter-field difference value or the inter-frame difference value obtained by the motion correction is smaller than the inter-field difference value or the inter-frame difference value that is not subjected to the motion correction, the inter-field difference value or the inter-frame difference value obtained by the motion correction is determined as a criterion. The video signal processing apparatus, wherein if the value is equal to or greater than the value, the motion vector is set to a predetermined value. The comparison between the inter-field difference value or inter-frame difference value obtained by the motion correction and the inter-field difference value or inter-frame difference value that is not subjected to the motion correction is performed. The video signal processing apparatus according to claim 1, wherein the video signal processing device is executed by comparing an absolute value sum with an absolute value sum of an inter-field difference or an inter-frame difference that is not motion-corrected in the fixed region. The video signal processing apparatus according to claim 1 or 2, wherein the predetermined value is a value of 0. After the motion of the field or frame is corrected by the motion vector, the number of fields or the number of frames is converted by creating an interpolation field or an interpolation frame by interpolating between fields or frames. The video signal processing apparatus according to claim 1, 2, or 3. In a video signal processing method of processing a video signal by a motion vector,
By correcting the motion of consecutive fields or frames by the motion vector detected from the video signal and detecting the inter-field difference value or inter-frame difference value, the inter-field difference value or inter-frame difference value by motion correction is detected. Detect
By detecting the inter-field difference value or inter-frame difference value without correcting the motion of the continuous field or frame, the inter-field difference value or the inter-frame difference value without motion correction is detected,
By comparing the inter-field difference value or inter-frame difference value by the motion correction and the inter-field difference value or inter-frame difference value not subjected to the motion correction, the motion vector is set to a predetermined value,
Even if the inter-field difference value or the inter-frame difference value obtained by the motion correction is smaller than the inter-field difference value or the inter-frame difference value that is not subjected to the motion correction, the inter-field difference value or the inter-frame difference value obtained by the motion correction is determined as a criterion. If the value is equal to or greater than the value, the motion vector is set to a predetermined value.

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