JP4239796B2 - Image signal processing apparatus and processing method - Google Patents

Description

  The present invention relates to an image signal processing apparatus and processing method for converting an interlace signal into a progressive signal.

  Specifically, the present invention obtains the motion information of the interpolation position by using the frame motion information of the current field in the pixel unit corresponding to the interpolation position and the frame motion information of the previous field of the block unit corresponding to the interpolation position. The present invention relates to an image signal processing apparatus and processing method capable of greatly reducing the capacity of a storage element (memory) and reducing the circuit scale.

  Many image signals such as television and video are interlaced image signals (interlace signals). On the other hand, the image signal of the computer is a progressive image signal (progressive signal). Thus, for example, in order to display a computer image and a television image on a computer display screen, the interlace signal must be converted into a progressive signal.

  In addition, since the interlace signal alternately uses the signals of each line constituting the signal of one frame as the signal of the odd field and the signal of the even field, flickering occurs if there is a thin horizontal line in the image. However, in the progressive signal, such a situation does not occur, and even if there is a thin horizontal line in the image, it is displayed neatly. Therefore, recently, some television receivers for home use internally convert an interlace signal into a progressive signal and display an image in a progressive manner.

  As shown in FIG. 7, the interlaced signal is composed of two frames, odd and even, each having a line signal that is shifted every other line. When performing so-called IP (interlace-progressive) conversion, which converts this interlace signal into a progressive signal, interpolation data (pixel data) is generated for each line without pixel data.

  In this case, as shown in FIG. 8, generally, a motion detection process is performed to divide the motion region into a still region, interpolation data is generated from the data in the field for the motion region, and the previous region is Alternatively, pixel data on the same line in the subsequent field is used as interpolation data as it is.

  Conventionally, as motion detection processing at the time of performing IP conversion, various methods have been proposed as described in Patent Documents 1 to 5, for example.

  As this motion detection processing, the current field frame motion information of the pixel unit is obtained using the current field signal of the interlace signal and the signal of the previous frame, and the frame motion information is stored in the storage element, and the interpolation position is obtained. It is conceivable to obtain the motion information of the interpolation position based on the frame motion information of the current field in pixel units corresponding to and the frame motion information of the previous field in pixel units corresponding to the interpolation position stored in the storage element. .

FIG. 9 shows a configuration of an IP conversion circuit 200 that performs such motion detection processing.
The IP conversion circuit 200 has an input terminal 201 for inputting an image signal V0 that is an interlaced signal, and an image signal V1 of the previous field by delaying the image signal V0 of the current field input to the input terminal 201 by one field period. A storage element (field memory) 202 as a delay means for obtaining V1 and an image signal V1 one field before output from the storage element 202 are further delayed by one field period, two fields before (one frame before). And a storage element (field memory) 203 as delay means for obtaining the image signal V2.

  The IP conversion circuit 200 includes a pixel unit frame motion information acquisition circuit 204. The motion information acquisition circuit 204 uses the current field image signal V0 input to the input terminal 201 and the image signal V2 of one frame (two fields) before output from the storage element 203 to detect the current field in units of pixels. Frame motion information M0FM is acquired.

  As shown in FIG. 10, when there is an interpolation position P in the current field, the motion information acquisition circuit 204, the data of the pixel a of the line after the interpolation position P and the pixel of the line two fields before corresponding to this line The absolute difference value with respect to the data b is obtained, and this absolute difference value is set as the frame motion information M0FM of the current field in units of pixels corresponding to the interpolation position P. In this case, the frame motion information M0FM indicates that the greater the value, the greater the motion. The same applies to other motion information described later.

  In addition, the IP conversion circuit 200 includes a storage element 205 that stores the frame motion information M0FM of the current field in units of pixels acquired by the motion information acquisition circuit 204. This storage element 205 constitutes a delay means for delaying the frame motion information M0FM of the current field by one field period to obtain the frame motion information M1FM one field before in pixel units. As shown in FIG. 10, the frame motion information M1FM one field before corresponds to, for example, the absolute difference value of the data of the pixels c and d of the line one field before and three fields before corresponding to the interpolation position P.

  In addition, the IP conversion circuit 200 includes the frame motion information M0FM of the current field in pixel units corresponding to the interpolation position acquired by the motion information acquisition circuit 204 and 1 pixel unit corresponding to the interpolation position stored in the storage element 205. Based on the frame motion information M1FM before the field, it has a pixel unit motion determination circuit 206 that acquires the motion information MV of the interpolation position and obtains a coefficient α (0 ≦ α ≦ 1) of a value corresponding to the motion information MV. ing.

  FIG. 11 shows a configuration example of the pixel unit motion determination circuit 206. The motion determination circuit 206 selects the maximum value of the frame motion information M0FM and M1FM, and outputs the maximum value selection unit 206a that outputs the maximum value as the motion information MV of the interpolation position, and an α value that converts the motion information MV into a coefficient α. It comprises a conversion unit 206b. The α value conversion unit 206 performs conversion so that the value of the coefficient α approaches 1 as the value of the motion information MV increases.

  Returning to FIG. 9, the IP conversion circuit 200 includes a motion adaptive interpolation calculation circuit 207. The interpolation calculation circuit 207 generates pixel data Dip at the interpolation position based on the coefficient α having a value corresponding to the motion information MV at the interpolation position obtained by the motion determination circuit 206. In this case, the interpolation calculation circuit 207 uses pixel data existing around the interpolation position P included in the image signal V0 of the current field and the previous one field at a mixing ratio corresponding to the value of the motion information MV and hence the coefficient α. Pixel data existing around the interpolation position P included in the image signal V1 are mixed to generate pixel data Dip at the interpolation position. In the interpolation calculation circuit 207, pixel data Dip is generated as described above at each interpolation position on each interpolation line in the vertical direction, and signals of each interpolation line are sequentially generated.

  FIG. 12 shows a configuration example of a main part of the motion adaptive interpolation calculation circuit 207. The interpolation calculation circuit 207 includes an averaging unit 207a that calculates an average value Dae of data Da and De of pixels a and e on the lines before and after the interpolation position P, a multiplier 207b that multiplies the average value Dae by a coefficient α, Multiplier 207c that multiplies the coefficient D (1-α) by the data Dc of the pixel c of the previous line corresponding to the interpolation position P, and the output signals of the multipliers 207b and 207c are added to obtain the pixel data Dip at the interpolation position. And an adder 207d to be obtained (see FIG. 10).

  Returning to FIG. 9, the IP conversion circuit 200 alternately takes out the signal of each line of the image signal V0 of the current field input to the input terminal 201 and the signal of each interpolation line generated by the interpolation operation circuit 207. And an output line selection circuit 208 for obtaining an image signal Vp which is a progressive signal, and an output terminal 209 for outputting the image signal Vp.

The operation of the IP conversion circuit 200 shown in FIG. 9 will be described.
An image signal V 0 that is an interlace signal is input to the input terminal 201. This image signal V0 is supplied to the storage element 202 and delayed by one field period. The image signal V1 one field before output from the storage element 202 is supplied to the storage element 203 and delayed by one field period.

  The image signal V 0 of the current field input to the input terminal 201 and the image signal V 2 of 2 fields before (1 frame before) output from the storage element 203 are supplied to the pixel unit frame motion information acquisition circuit 204. In the motion information acquisition circuit 204, the frame motion information M0FM of the current field in units of pixels is acquired using the image signals V0 and V2. That is, in the motion information acquisition circuit 204, the absolute value of the difference between the data of the pixel a in the line after the interpolation position P of the interpolation line P in the current field and the data of the pixel b in the line two fields before corresponding to this line is calculated. The absolute value of the difference is obtained as frame motion information M0FM of the current field corresponding to the interpolation position P (see FIG. 10).

  As described above, the frame motion information M0FM of the current field in units of pixels acquired by the motion information acquisition circuit 204 is stored in the storage element 205 and delayed by one field period. That is, the frame motion information M1FM of the previous field is obtained from the storage element 205. The frame motion information M1FM one field before corresponds to the absolute difference value of the data of the pixels c and d of the line one field before and three fields before corresponding to the interpolation position P (see FIG. 10).

  The frame motion information M0FM of the current field acquired by the motion information acquisition circuit 204 and the frame motion information M1FM of the previous field output from the storage element 205 are supplied to the pixel unit motion determination circuit 206. The motion determination circuit 206 acquires motion information MV of the interpolation position based on the frame motion information M0FM and M1FM, and obtains a coefficient α (0 ≦ α ≦ 1) having a value corresponding to the motion information MV. In this case, for example, the maximum value of the frame motion information M0FM and M1FM is selected as the motion information MV at the interpolation position, and this motion information MV is converted into a coefficient α. Here, the value of the coefficient α approaches 1 as the value of the motion information MV increases.

  The coefficient α obtained by the motion determination circuit 206 is supplied to the motion adaptive interpolation calculation circuit 207. Further, the interpolation operation circuit 207 is supplied with the image signal V 0 of the current field input to the input terminal 201 and the image signal V 1 of the previous field output from the storage element 202. In the interpolation calculation circuit 207, the pixel data existing around the interpolation position P included in the image signal V0 of the current field and the image signal V1 of the previous field at the mixing ratio corresponding to the value of the motion information MV and hence the coefficient α. The pixel data existing around the interpolation position P included in is mixed to generate pixel data Dip at the interpolation position.

  In this case, as the motion information MV increases and the value of the coefficient α approaches 1, the mixture ratio of the pixel data existing around the interpolation position P included in the image signal V0 in the current field is increased. That is, mixing is performed so that the signal component of the current field increases in the motion region, while the signal component of the previous field increases in the still region.

  In the interpolation calculation circuit 207, pixel data Dip is generated as described above at each interpolation position on each interpolation line in the vertical direction, and signals of each interpolation line are sequentially generated. Thus, the signal of each interpolation line generated by the interpolation calculation circuit 207 is supplied to the output line selection circuit 208. The output line selection circuit 208 is supplied with the signals of the respective lines of the image signal V0 of the current field input to the input terminal 201. In the output line selection circuit 208, the signal of each line of the image signal V0 of the current field and the signal of each interpolation line corresponding thereto are alternately extracted to double the number of lines, and the image signal Vp which is a progressive signal is obtained. can get. The image signal Vp is derived to the output terminal 209.

JP 2002-185933 A JP 2002-112202 A Japanese Patent Laid-Open No. 2002-77830 JP 2002-77831 A JP 2001-339694 A

  In the above-described IP conversion circuit 200 shown in FIG. 9, in order to obtain the frame motion information M1FM of the previous field, the memory for storing the frame motion information M0FM of the current field for all the pixels acquired by the motion information acquisition circuit 204. The element (field memory) 205 is required, and there is a problem that the memory capacity increases and the circuit scale increases.

  An object of the present invention is to greatly reduce the capacity of a memory element (memory) and reduce the circuit scale.

Image signal processing apparatus according to the present invention, by using the signal and the previous frame signal of the current field Lee Ntaresu signal, the first motion information acquisition to obtain frame motion information of the current field of pixel units corresponding to the interpolation position Second motion information acquisition for obtaining frame motion information of the current field in units of blocks corresponding to the interpolation position composed of a plurality of pixels, using the means, the signal of the current field of the interlace signal and the signal one frame before It means, and the second motion information storing frame motion information of the current field of the acquired blocks in acquisition means Ru obtain one field previous frame motion information storing means, obtaining a first motion information obtaining means has been in the current field of pixel units corresponding to the interpolation position the frame motion information and acquired by the storage means block a single corresponding to the interpolation position Mixing motion of one field previous frame motion information to select a larger motion information, a motion determination means for obtaining motion information of the interpolation position, which corresponds to the motion information obtained interpolation position in the motion determination means By the ratio, the pixel data existing around the interpolation position included in the current field signal of the interlace signal and the pixel data existing around the interpolation position included in the signal one field before the interlace signal are mixed. And pixel data generating means for generating pixel data at the interpolation position.

The image signal processing apparatus according to the present invention, by using the signal and the previous frame signal of the current field Lee Ntaresu signal, the first motion obtaining frame motion information of the current field of pixel units corresponding to the interpolation position An information acquisition step and a second motion for obtaining frame motion information of the current field in units of blocks corresponding to the interpolation position composed of a plurality of pixels, using the signal of the current field of the interlace signal and the signal of one frame before information and obtaining step, the second storing step frame motion information of one field before storing the frame motion information of the current field to the storage elements Ru obtain a block unit obtained by the motion information obtaining step, a first motion frame motion information and storing steps in the current field of pixel units corresponding to interpolation positions obtained by the information obtaining step Movement of one field previous frame motion information of the block unit corresponding to the obtained interpolation position selects a larger motion information, a motion determination step of obtaining the motion information of the interpolation position, resulting in the motion determination step The data of the pixel existing around the interpolation position included in the signal of the current field of the interlace signal and the interpolation position included in the signal one field before the interlace signal at a mixing ratio corresponding to the motion information of the interpolation position. A pixel data generation step of mixing pixel data existing in the periphery and generating pixel data at the interpolation position.

  In the present invention, the interlace signal is converted into a progressive signal. Using the current field signal of the interlaced signal and the signal one frame before, the frame motion information of the current field in units of pixels can be obtained. Also, using the current field signal of the interlaced signal and the signal one frame before, the frame motion information of the current field is obtained in units of blocks composed of a plurality of pixels. The frame motion information of the current field in block units is stored in the storage element. This is because the frame motion information in the current field in units of pixels has the property of being similar between adjacent pixels, and the frame motion information can be handled in units of blocks in which a plurality of pixels are combined. .

  Then, based on the frame motion information of the current field in pixel units corresponding to the interpolation position and the frame motion information of the previous field in block units corresponding to the interpolation position stored in the storage element (storage means), the interpolation position Movement information can be obtained. For example, among the frame motion information of the current field in units of pixels corresponding to the interpolation position and the frame motion information of one block before corresponding to the interpolation position, the motion information indicating that the motion is larger is the motion information of the interpolation position. It is said.

  With the mixing ratio based on the motion information of the interpolated position, pixel data existing around the interpolated position included in the current field signal of the interlaced signal and the interpolated position included in the signal one field before the interlaced signal. Pixel data existing in the periphery are mixed to generate pixel data at the interpolation position. In this case, the larger the motion indicated by the motion information of the interpolation position, the greater the mixing ratio of the pixel data existing around the interpolation position included in the current field signal.

  As described above, according to the present invention, the motion information of the interpolation position is obtained using the one-frame motion information of the current field in the pixel unit corresponding to the interpolation position and the frame motion information of the previous field of the block unit corresponding to the interpolation position. Thus, no storage element for storing the frame motion information of the current field for all pixels is required, and therefore the capacity of the storage element (memory) can be greatly reduced and the circuit scale can be reduced.

  The present invention may further include third motion information acquisition means for obtaining field motion information of the current field in units of pixels using the current field signal of the interlace signal and the signal one field before. Good. In this case, it corresponds to the interpolation position together with the frame motion information of the current field in pixel units corresponding to the interpolation position and the frame motion information of the previous field in block units corresponding to the interpolation position stored in the storage element (storage means). Based on the field motion information of the current field in pixel units, motion information of the interpolation position is obtained.

  For example, the motion information indicating that the motion is larger is first selected from the frame motion information of the current field in units of pixels corresponding to the interpolation position and the frame motion information of the previous field in units of blocks corresponding to the interpolation position. The motion information indicating that the motion is smaller among the motion information and the field motion information of the current field of the pixel unit corresponding to the interpolation position is the motion information of the interpolation position.

By setting the frame motion information one field before as a block unit, the change between the motion region and the still region becomes a block shape, and there is a possibility that block-like noise appears in the image by the progressive signal. However, we have use the field motion information of the current field of pixel units as described above, finally compared to field motion information of the current field of pixel units to obtain a motion information of the interpolation position, the motion region and the still region The change of becomes a block shape, and it is possible to reduce the appearance of block noise in the image by the progressive signal.

  According to the present invention, the motion information of the interpolation position is obtained using the frame motion information of the current field in the pixel unit corresponding to the interpolation position and the frame motion information of the previous field of the block unit corresponding to the interpolation position. There is no need for a storage element for storing the frame motion information of the current field for all pixels, so that the capacity of the storage element (memory) can be greatly reduced, and the circuit scale can be reduced.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an IP conversion circuit 100 as an embodiment.
This IP conversion circuit 100 has an input terminal 101 for inputting an image signal V0, which is an interlaced signal, and the image signal V0 of the current field input to the input terminal 101, delayed by one field period, and the image signal of the previous field A storage element (field memory) 102 as a delay means for obtaining V1 and an image signal V1 one field before output from the storage element 102 are further delayed by one field period, two fields before (one frame before) And a storage element (field memory) 103 as delay means for obtaining the image signal V2.

  In addition, the IP conversion circuit 100 includes a pixel unit frame motion information acquisition circuit 104. The motion information acquisition circuit 104 uses the current field image signal V0 input to the input terminal 101 and the image signal V2 of one frame (two fields) before output from the storage element 103 to detect the current field in units of pixels. Frame motion information M0FM is acquired.

  As shown in FIG. 2, when there is an interpolation position P in the current field, the motion information acquisition circuit 104 has the data of the pixel a in the line after this interpolation position P and the pixel in the line two fields before corresponding to this line. The absolute difference value of the data b is obtained, and this absolute difference value is used as the frame motion information M0FM of the current field in units of pixels corresponding to the interpolation position P. In this case, the frame motion information M0FM indicates that the greater the value, the greater the motion. The same applies to other motion information described later.

  Note that the frame motion information M0FM is not limited to that described above. For example, the absolute difference value between the pixel e data of the line before the interpolation position P and the data of the pixel f of the line two fields before corresponding to this line is obtained, and this absolute difference value is obtained as the frame motion information M0FM. It may be. Further, for example, the absolute value of the difference between the average value of the data of the pixels a and e of the lines before and after the interpolation position P and the average value of the data of the pixels b and f of the previous two lines corresponding to the preceding and following lines is obtained. You may make it acquire this difference absolute value as frame motion information M0FM.

  The IP conversion circuit 100 includes a block unit frame motion information acquisition circuit 105. The motion information acquisition circuit 105 uses the current field image signal V0 input to the input terminal 101 and the image signal V2 of one frame (two fields) before output from the storage element 103, so that the current field of the block unit. Frame motion information MB0FM is acquired. This is because the frame motion information M0FM of the current field in units of pixels has the property of being similar between adjacent pixels, and the frame motion information can be handled in units of blocks in which a plurality of pixels are combined. is there.

  As shown in FIG. 2, when there is an interpolation position P in the current field, the motion information acquisition circuit 105 includes data of a plurality of pixels (blocks) in the space area AR0 including the interpolation position P and the plurality of pixels (blocks). The difference absolute value of corresponding pixels between the data of a plurality of pixels (blocks) in the space area AR2 two fields before corresponding to is obtained, and then the average value of each difference absolute value is obtained, and this average value is calculated as the interpolation position. The frame motion information MB0FM of the current field in units of blocks corresponding to P is assumed.

  Note that the screen area of the current field is divided into a plurality of space areas AR0. Similarly, the screen area two fields before is also divided into a plurality of space areas AR2. For example, one spatial area AR0 includes a total of 32 pixels of 8 horizontal pixels and 4 vertical pixels as shown in FIG. In this case, although not shown, one spatial area AR2 includes a total of 32 pixels of 8 horizontal pixels and 4 vertical pixels.

  With respect to each interpolation position P included in one spatial area AR0, the frame motion information MB0FM of the current field in block units is all the same, so that the motion information acquisition circuit 105 has 32 locations for one spatial area AR0. Instead of obtaining the frame motion information MB0FM corresponding to each interpolation position P (illustrated by a broken line in FIG. 3), it is only necessary to obtain the frame motion information MB0FM corresponding to one interpolation position P.

  In addition, the IP conversion circuit 100 includes a storage element 106 that stores the frame motion information MB0FM of the current field in block units acquired by the motion information acquisition circuit 105. This storage element 106 constitutes delay means for delaying the frame motion information MB0FM of the current field by one field period to obtain the frame motion information MB1FM of the previous field. As shown in FIG. 2, the frame motion information MB1FM one field before, for example, corresponds to a plurality of pixels (blocks) in the space area AR0 in which the interpolation position P is included. A difference absolute value between corresponding pixels is obtained between the data of (block) and data of a plurality of pixels (block) in the spatial area AR3 three fields before corresponding to the plurality of pixels (block), and each difference absolute value Is equivalent to an average value obtained by averaging.

  The IP conversion circuit 100 includes a pixel unit field motion information acquisition circuit 107. The motion information acquisition circuit 107 uses the current-field image signal V0 input to the input terminal 101 and the previous-field image signal V1 output from the storage element 102, so that the current-field field motion information M0FD in units of pixels. To get.

  As shown in FIG. 2, when there is an interpolation position P in the current field, the motion information acquisition circuit 107 corresponds to the average value of the data of the pixels a and e on the lines before and after the interpolation position P and the interpolation position P. The absolute difference value of the data of the pixel c before the field is obtained, and this absolute difference value is used as the field motion information M0FD of the current field in the pixel unit corresponding to the interpolation position P.

  In addition, the IP conversion circuit 100 includes the frame motion information M0FM of the current field in units of pixels corresponding to the interpolation position acquired by the motion information acquisition circuit 104, and 1 in units of blocks corresponding to the interpolation positions stored in the storage element 106. Based on the frame motion information MB1FM before the field and the field motion information M0FD of the current field corresponding to the interpolation position acquired by the motion information acquisition circuit 107, the motion information MV of the interpolation position is acquired, and this motion information MV The pixel unit motion determination circuit 108 obtains a coefficient α (0 ≦ α ≦ 1) having a value corresponding to.

  FIG. 4 shows a configuration example of the pixel unit motion determination circuit 108. The motion determination circuit 108 selects a maximum value selection unit 108a that selects the maximum value of the frame motion information M0FM and MB1FM, selects the maximum value and the minimum value of the field motion information M0FD, and outputs the minimum value as motion information MV. A minimum value selection unit 108b for converting the motion information MV into a coefficient α, and an α value conversion unit 108c. The α value conversion unit 108 c performs conversion so that the value of the coefficient α approaches 1 as the value of the motion information MV increases.

  Returning to FIG. 1, the IP conversion circuit 100 includes a motion adaptive interpolation calculation circuit 109. The interpolation calculation circuit 109 generates pixel data Dip at the interpolation position based on the coefficient α having a value corresponding to the motion information MV at the interpolation position obtained by the motion determination circuit 108. In this case, the interpolation calculation circuit 109 uses the motion information MV, and therefore the mixing ratio corresponding to the value of the coefficient α, and the pixel data existing around the interpolation position P included in the image signal V0 of the current field and the previous one field. Pixel data existing around the interpolation position P included in the image signal V1 is mixed to generate pixel data Dip at the interpolation position. In the interpolation calculation circuit 109, pixel data Dip is generated as described above at each interpolation position on each interpolation line in the vertical direction, and signals of each interpolation line are sequentially generated.

  The interpolation calculation circuit 109 is configured as shown in FIG. 12, for example, similarly to the motion adaptive interpolation calculation circuit 109 in the IP conversion circuit 200 shown in FIG. That is, the interpolation calculation circuit 109 includes an averaging unit 207a that calculates the average value Dae of the data Da and De of the pixels a and e on the lines before and after the interpolation position P, and a multiplier 207b that multiplies the average value Dae by a coefficient α. And the multiplier 207c that multiplies the data Dc of the pixel c of the previous line corresponding to the interpolation position P by the coefficient (1-α), and the output signals of the multipliers 207b and 207c are added to obtain pixel data at the interpolation position. An adder 207d for obtaining Dip (see FIG. 2).

  The pixels existing around the interpolation position P included in the image signal V0 in the current field are not limited to the pixels a and e. For example, in addition to one of the pixels a and e or other than the pixels a and e. Furthermore, peripheral pixels may be included. Similarly, the pixel data existing around the interpolation position P included in the image signal V1 one field before is not limited to the data of the pixel c, and may further include peripheral pixels.

Returning to FIG. 1, IP conversion circuit 100, alternating with the signal of each line of the image signal V0 of the current field to be inputted to the input terminal 1 01, and a signal of each interpolation line generated by the interpolation calculation circuit 109 And an output line selection circuit 110 for obtaining an image signal Vp, which is a progressive signal, and an output terminal 111 for outputting the image signal Vp.

The operation of the IP conversion circuit 100 shown in FIG. 1 will be described.
An image signal V 0 that is an interlace signal is input to the input terminal 101. This image signal V0 is supplied to the storage element 102 and delayed by one field period. The image signal V1 one field before output from the memory element 102 is supplied to the memory element 103 and delayed by one field period.

  The image signal V0 of the current field input to the input terminal 101 and the image signal V2 of 2 fields before (1 frame before) output from the storage element 103 are supplied to the pixel unit frame motion information acquisition circuit 104. In the motion information acquisition circuit 104, the frame motion information M0FM of the current field in units of pixels is acquired using the image signals V0 and V2. That is, in the motion information acquisition circuit 104, for example, the absolute difference between the data of the pixel a in the line after the interpolation position P of the interpolation line P in the current field and the data of the pixel b in the line two fields before corresponding to this line. A value is obtained, and this difference absolute value is used as frame motion information M0FM of the current field in units of pixels corresponding to the interpolation position P (see FIG. 2).

  Also, the image signal V 0 of the current field input to the input terminal 101 and the image signal V 2 of 2 fields before (1 frame before) output from the storage element 103 are supplied to the block unit frame motion information acquisition circuit 105. In the motion information acquisition circuit 105, the frame motion information MB0FM of the current field in block units is acquired using the image signals V0 and V2. That is, in the motion information acquisition circuit 105, the data of a plurality of pixels (blocks) in the space area AR0 of the current field including the interpolation position P and the data in the space area AR2 two fields before corresponding to the plurality of pixels (blocks). The difference absolute value between corresponding pixels among the data of a plurality of pixels (blocks) is obtained, and then the average value of each difference absolute value is obtained. This average value is the current value of the block unit corresponding to the interpolation position P. The frame motion information is MB0FM.

  As described above, the frame motion information MB0FM of the current field in block units acquired by the motion information acquisition circuit 105 is stored in the storage element 106 and delayed by one field period. That is, the frame motion information MB1FM of the previous field is obtained from the memory element 106. The frame motion information MB1FM one field before includes, for example, data of a plurality of pixels (blocks) in the space area AR1 one field before corresponding to the plurality of pixels (blocks) in the space area AR0 including the interpolation position P, and An average obtained by calculating a difference absolute value of corresponding pixels among data of a plurality of pixels (block) in the space area AR3 three fields before corresponding to the plurality of pixels (block), and further averaging each difference absolute value This corresponds to the value (see FIG. 2).

  In addition, the image signal V 0 of the current field input to the input terminal 101 and the image signal V 1 of the previous field output from the storage element 102 are supplied to the pixel unit field motion information acquisition circuit 107. The motion information acquisition circuit 107 acquires field motion information M0FD of the current field in pixel units using the image signals V0 and V1. That is, in the motion information acquisition circuit 107, the difference between the average value of the data of the pixels a and e of the lines before and after the interpolation position P of the interpolation line P of the current field and the data of the pixel c of the previous field corresponding to the interpolation position P. An absolute value is obtained, and this difference absolute value is used as field motion information M0FD of the current field in units of pixels corresponding to the interpolation position P (see FIG. 2).

  The frame motion information M0FM of the current field in units of pixels acquired by the motion information acquisition circuit 104, the frame motion information M1FM of the previous field in units of blocks output from the storage element 106, and the pixel units acquired by the motion information acquisition circuit 107 The field motion information M0FD of the current field is supplied to the pixel unit motion determination circuit 108. The motion determination circuit 108 acquires motion information MV at the interpolation position based on the frame motion information M0FM, MB1FM and the field motion information M0FD, and a coefficient α (0 ≦ α ≦ 1) corresponding to the motion information MV. Is obtained. In this case, for example, the maximum value of the frame motion information M0FM and MB1FM and the minimum value of the field motion information M0FD are selected as the motion information MV, and the motion information MV is converted into a coefficient α. Here, the value of the coefficient α approaches 1 as the value of the motion information MV increases.

  The coefficient α obtained by the motion determination circuit 108 is supplied to the motion adaptive interpolation calculation circuit 109. Further, the interpolation calculation circuit 109 is supplied with the image signal V 0 of the current field input to the input terminal 101 and the image signal V 1 of the previous field output from the storage element 102. In the interpolation calculation circuit 109, data of pixels existing around the interpolation position P included in the image signal V0 of the current field and the image signal V1 of the previous field at a mixing ratio corresponding to the value of the motion information MV and hence the coefficient α. The pixel data existing around the interpolation position P included in is mixed, and pixel data Dip at the interpolation position is generated.

  In this case, as the motion information MV increases and the value of the coefficient α approaches 1, the mixing ratio of the pixel data existing around the interpolation position P included in the image signal V0 in the current field is increased. That is, mixing is performed so that the signal component of the current field increases in the motion region, while the signal component of the previous field increases in the still region.

  In the interpolation calculation circuit 109, pixel data Dip is generated as described above at each interpolation position on each interpolation line in the vertical direction, and signals of each interpolation line are sequentially generated. Thus, the signal of each interpolation line generated by the interpolation calculation circuit 109 is supplied to the output line selection circuit 110. In addition, the output line selection circuit 110 is supplied with the signal of each line of the image signal V0 of the current field input to the input terminal 101. In the output line selection circuit 110, the signal of each line of the image signal V0 of the current field and the signal of each interpolation line corresponding thereto are alternately extracted to double the number of lines, and the image signal Vp, which is a progressive signal, is obtained. can get. The image signal Vp is derived to the output terminal 111.

  In the present embodiment described above, the motion determination circuit 108 does not use the frame motion information of the previous pixel unit corresponding to the interpolation position, but the previous frame motion information of the block unit corresponding to the interpolation position. The motion information MV of the interpolation position is obtained using MB1FM, and the storage element 106 does not need a storage element for storing the frame motion information of the current field for all the pixels, and thus the capacity of the storage element 106 is greatly increased. The circuit scale can be reduced. For example, as described above, when one block is composed of 8 horizontal pixels and 4 vertical pixels, the capacity of the storage element 106 is 1/32 compared with the case of storing frame motion information for all pixels. it can.

  In this embodiment, when the motion determination circuit 108 obtains the motion information MV of the interpolation position, the field motion information M0FD of the current field in units of pixels is also used, and the frame motion information M0FM, MB1FM is used by the minimum value selection unit 108b. Since the final motion information MV of the interpolation position is obtained by comparing the maximum value of the field and the field motion information M0FD of the pixel unit, instead of using the frame motion information of one field before the pixel unit, the block Even when the frame motion information MB1FM of one unit before is used, it is possible to reduce the occurrence of block noise in an image due to a progressive signal due to the change of the motion region and the still region being in a block shape.

  Note that the processing in the IP conversion circuit 100 of FIG. 1 can be realized by software, for example, by an image signal processing device 300 as shown in FIG. First, the image signal processing apparatus 300 shown in FIG. 5 will be described. The image signal processing apparatus 300 includes a CPU 301 that controls the operation of the entire apparatus, a ROM (read only memory) 302 that stores an operation program of the CPU 301, and a RAM (random access memory) that constitutes a work area of the CPU 301. 303. These CPU 301, ROM 302, and RAM 303 are each connected to a bus 304.

  The image signal processing apparatus 300 also includes a hard disk drive (HDD) 305 and a drive 307 that handles the removable disk 306. These HDD 305 and drive 307 are each connected to a bus 304.

  Further, the image signal processing apparatus 300 includes a communication unit 309 that is connected to a communication network 308 such as the Internet by wire or wireless. The communication unit 309 is connected to the bus 304 via the interface 310.

  In addition, the image signal processing device 300 includes a user interface unit. The user interface unit includes a receiving unit 312 that receives a remote control signal RM from a remote control transmitter 311 and a display 314 that includes an LCD (liquid crystal display) or the like. The receiving unit 312 is connected to the bus 304 via the interface 313, and similarly the display 314 is connected to the bus 304 via the interface 315.

  The image signal processing apparatus 300 also has an input terminal 316 for inputting an image signal V0 as an interlace signal, and an output terminal 318 for outputting an image signal Vp as a progressive signal. The input terminal 316 is connected to the bus 304 via the interface 317, and similarly, the output terminal 318 is connected to the bus 304 via the interface 319.

  Here, instead of storing the operation program or the like in the ROM 302 in advance as described above, for example, it may be downloaded from the communication network 308 such as the Internet via the communication unit 309 and stored in the HDD 305, RAM 303, or the like. it can. Further, this operation program or the like may be provided on the removable disk 306.

Further, instead of inputting from the input terminal 316 an image signal V0 to be processed, downloaded beforehand HDD305 Record to, or through the communication unit 30 9 from the communication network 308 such as the Internet, more removable disk 306 You may make it supply. Further, instead of outputting the processed image signal Vp to the output terminal 318, or in parallel therewith, it is supplied to the display 314 to display an image, and further stored in the HDD 305, via the communication unit 309, etc. It may be sent to the communication network 308 or recorded on the removable disk 306.

With reference to the flowchart of FIG. 6, the IP conversion processing procedure in the image signal processing apparatus 300 shown in FIG. 5 will be described.
First, in step ST1, processing is started, and in step ST2, an image signal V0 as an interlace signal is input for one frame or one field. When the image signal V0 is input from the input terminal 316, the image signal V0 is temporarily stored in the RAM 303. When the image signal V0 is recorded in the HDD 305, the image signal V0 is read from the HDD 305 and temporarily stored in the RAM 303. Further, when the image signal V 0 is supplied from the removable disk 306, the drive 307 reads out the image signal V 0 from the removable disk 306 and temporarily stores it in the RAM 303.

  Next, in step ST3, it is determined whether or not processing of all frames or all fields of the image signal V0 has been completed. When the process is finished, the process ends in step ST4. On the other hand, when the process is not finished, the process proceeds to step ST5.

  In this step ST5, using the image signal of the current field (field where the interpolation position exists) and the image signal of 2 fields before (1 frame before), the frame motion information M0FM of the current field in pixel units corresponding to the interpolation position is obtained. get. That is, in this step ST5, an absolute difference between the data of the pixel a in the line after the interpolation position P of the interpolation line P in the current field and the data of the pixel b in the line two fields before corresponding to this line is obtained. The absolute difference is set as frame motion information M0FM of the current field in units of pixels corresponding to the interpolation position P (see FIG. 2).

  Next, in step ST6, the frame motion information MB0FM of the current field in block units is acquired using the image signal of the current field (field where the interpolation position exists) and the image signal of 2 fields before (1 frame before). That is, in this step ST6, data of a plurality of pixels (blocks) in the space area AR0 of the current field including the interpolation position P and a plurality of pixels in the space area AR2 two fields before corresponding to the plurality of pixels (blocks) ( The absolute value of the difference between corresponding pixels among the data of the block) is obtained, then the average value of each absolute difference value is obtained, and this average value is obtained from the frame motion information MB0FM of the current field in block units corresponding to the interpolation position P. To do. Then, in step ST7, the frame motion information MB0FM of the current field in block units acquired in step ST6 is temporarily stored in a storage element such as the RAM 303.

  Next, in step ST8, field motion information M0FD of the current field in units of pixels is acquired using the image signal V0 of the current field and the image signal V1 of the previous field. That is, in this step ST8, the average value of the data of the pixels a and e of the lines before and after the interpolation position P of the interpolation line P of the current field and the absolute difference value of the data of the pixel c one field before corresponding to the interpolation position P are obtained. The absolute value of the difference is obtained as field motion information M0FD of the current field in pixel units corresponding to the interpolation position P (see FIG. 2).

  Next, in step ST9, the frame motion information M0FM of the current field in units of pixels acquired in step ST5, the frame motion information MB1FM of the previous field in units of blocks stored in the storage element, for example, the RAM 303, and in step ST8. Based on the field motion information M0FD of the current field in pixel units, the motion information MV of the interpolation position is acquired. In this case, for example, the maximum value of the frame motion information M0FM and MB1FM and the minimum value of the field motion information M0FD are selected as the motion information MV. In step ST9, a coefficient α (0 ≦ α ≦ 1) having a value corresponding to the motion information MV is further acquired. The conversion from the motion information MV to the coefficient α is performed with reference to, for example, a conversion table stored in the ROM 302, and the value of the coefficient α approaches 1 as the value of the motion information MV increases.

  Next, in step ST10, around the interpolation position included in the image signal of the current field (field including the interpolation position) at the mixing ratio corresponding to the motion information MV acquired in step ST9, and thus the value of the coefficient α. The pixel data Dip at the interpolation position is generated by mixing the data of the existing pixel and the data of the pixel existing around the interpolation position included in the image signal one field before. In this case, as the motion information MV increases and the value of the coefficient α approaches 1, the mixing ratio of the pixel data existing around the interpolation position included in the image signal of the current field is increased. Thus, mixing is performed so that the signal component of the current field increases in the motion region, while the signal component of the previous field increases in the still region.

  Next, in step ST11, it is determined whether or not the process of generating the interpolation data Dip for all the interpolation lines has been completed for the image signal V0 input in step ST2. If the process has not been completed, the process returns to step ST5 and proceeds to the process for the next interpolation position. Note that the processing of step ST6 and step ST7 may be performed corresponding to one interpolation position P with respect to each interpolation position P included in one space area AR0.

  When the process ends in step ST11, the process proceeds to step ST12. In step ST12, an image signal Vp as a progressive signal corresponding to the image signal V0 input in step ST2 is output. In this case, the signal of each line of the image signal V0 and the signal of each interpolation line corresponding thereto are alternately read out from the RAM 303 to obtain the image signal Vp, which is a progressive signal, in which the number of lines is doubled.

  In this case, the image signal Vp is output to the output terminal 318, the image signal Vp is recorded on the HDD 305, the image signal Vp is recorded on the removable disk 306 by the drive 307, and the image signal Vp is displayed on the display 314. And displaying an image thereby, sending the image signal Vp to the network 308 via the communication unit 309, and the like.

  After the process of step ST12, the process returns to step ST2, the process for inputting the next one frame or one field of the image signal V0 as the interlace signal is performed, and the same process as described above is repeated.

  In this way, by performing processing according to the flowchart shown in FIG. 6, it is possible to process the image signal V0 as an interlace signal and obtain an image signal Vp as a progressive signal. The processing order of steps ST5 to ST8 is not limited to the order shown in FIG.

  In the above embodiment, the image unit field motion information acquisition circuit 107 acquires the field motion information M0FD of the current field in pixel units, and the pixel unit motion determination circuit 108 includes the frame motion information M0FM and MB1FM. This field motion information M0FD is also used to obtain motion information MV at the interpolation position.

  However, a configuration in which the image unit field motion information acquisition circuit 107 is not provided, that is, a configuration in which the field motion information M0FD is not used in the pixel unit motion determination circuit 108 is also conceivable. In this case, the motion determination circuit 108 obtains the motion information MV of the interpolation position based on the frame motion information M0FM and MB1FM. For example, the motion determination circuit 108 uses the maximum value of the frame motion information M0FM and MB1FM as the motion information MV of the interpolation position.

  According to the present invention, the motion information of the interpolation position is obtained by using the frame motion information of the current field in units of pixels corresponding to the interpolation position and the frame motion information of the previous field in units of blocks corresponding to the interpolation position. (Memory) capacity can be greatly reduced and the circuit scale can be reduced, and can be applied to the use of converting an interlaced signal into a progressive signal based on motion information.

It is a block diagram which shows the structure of the IP converter circuit as embodiment. It is a figure for demonstrating IP conversion processing. It is a figure for demonstrating IP conversion processing. It is a block diagram which shows the structure of a pixel unit motion determination circuit. It is a block diagram which shows the structure of the image signal processing apparatus for implement | achieving by software. It is a flowchart which shows the procedure of IP conversion processing. It is a figure for demonstrating an interlace signal. It is a figure for demonstrating the process of general IP conversion. It is a block diagram which shows the structural example of an IP conversion circuit. It is a figure for demonstrating IP conversion processing. It is a block diagram which shows the structure of a pixel unit motion determination circuit. It is a block diagram which shows the structure of the principal part of a motion adaptive interpolation calculation circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... IP conversion circuit, 101 ... Input terminal, 102, 103, 106 ... Memory element, 104 ... Pixel unit frame motion information acquisition circuit, 105 ... Block unit frame motion information acquisition circuit, 107 ... pixel unit field motion information acquisition circuit, 108 ... pixel unit motion determination circuit, 108a ... maximum value selection unit, 108b ... minimum value selection unit, 108c ... α value conversion unit, 109 ... motion adaptive interpolation calculation circuit, 110 ... output line selection circuit, 111 ... output terminal, 207a ... averaging unit, 207b, 207c ... multiplier, 207d ... adder, 300 ... Image signal processing equipment

Claims (4)

Using the signal and the previous frame signal of the current field Lee Ntaresu signal, the first motion information obtaining means for obtaining a frame motion information of the current field of pixel unit corresponding to the interpolation position,
Second motion information acquisition means for obtaining frame motion information of the current field in units of blocks corresponding to an interpolation position composed of a plurality of pixels, using the signal of the current field of the interlace signal and the signal of one frame before; ,
And obtained Ru storage means 1 field previous frame motion information storing frame motion information of the current field of the acquired said block in the second motion information acquisition means,
The frame motion information of the current field in units of pixels corresponding to the interpolation position acquired by the first motion information acquisition unit and the frame motion information of the previous field in units of blocks corresponding to the interpolation position acquired by the storage unit . A motion determination unit that selects motion information having a larger motion and obtains motion information of the interpolation position;
Data of pixels existing around the interpolation position included in the current field signal of the interlace signal and 1 of the interlace signal at a mixing ratio corresponding to the motion information of the interpolation position obtained by the motion determination means. by mixing the data of pixels existing in the neighborhood of the interpolation position included in the field before the signal, images signal processing apparatus Ru and a pixel data generation means for generating pixel data of the interpolation position. Third motion information acquisition means for obtaining field motion information of the current field in units of pixels corresponding to the interpolation position using the signal of the current field of the interlace signal and the signal of the previous field,
The movement determination means is
The frame motion information of the current field in units of pixels corresponding to the interpolation position acquired by the first motion information acquisition unit and the frame motion information of the previous field in units of blocks corresponding to the interpolation position acquired by the storage unit . Among them, the motion information having the larger motion is selected, and the motion is smaller among the selected motion information and the field motion information of the current field of the pixel unit corresponding to the interpolation position acquired by the third motion information acquisition means. select the motion information, the image signal processing apparatus according to obtain Ru請 Motomeko 1 motion information of the interpolation position. Using the signal and the previous frame signal of the current field Lee Ntaresu signal, the first motion information obtaining step of obtaining a frame motion information of the current field of pixel unit corresponding to the interpolation position,
A second motion information acquisition step for obtaining frame motion information of the current field in units of blocks corresponding to the interpolation positions composed of a plurality of pixels, using the signal of the current field of the interlaced signal and the signal one frame before; ,
And obtained Ru storing step the frame motion information of one field before storing the frame motion information of the current field to the storage elements of the block unit obtained by the second motion information acquisition step,
The frame motion information of the current field in units of pixels corresponding to the interpolation position acquired in the first motion information acquisition step and the frame motion information of the previous field in blocks corresponding to the interpolation position acquired in the storage step . A motion determination step of selecting motion information having a larger motion and obtaining motion information of the interpolation position;
Data of pixels existing around the interpolation position included in the current field signal of the interlace signal and 1 of the interlace signal at a mixing ratio corresponding to the motion information of the interpolation position obtained in the motion determination step. by mixing the data of pixels existing in the neighborhood of the interpolation position included in the field before the signal, images signal processing method Ru and a pixel data generation step of generating pixel data of the interpolation position. A third motion information acquisition step of obtaining field motion information of the current field in units of pixels corresponding to the interpolation position using the signal of the current field of the interlace signal and the signal of the previous field;
In the motion determination step,
The frame motion information of the current field in units of pixels corresponding to the interpolation position acquired in the first motion information acquisition step and the frame motion information of the previous field in blocks corresponding to the interpolation position acquired in the storage step . The motion information having the larger motion is selected, and the motion is smaller among the selected motion information and the field motion information of the current field in the pixel unit corresponding to the interpolation position acquired in the third motion information acquisition step. select the motion information, the image signal processing method according to obtain Ru請 Motomeko 3 motion information of the interpolation position.

Images