JP2005151135A - Apparatus and method of determining picture boundary, and apparatus and method of processing picture signal using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the occurrence of flickers on an upper boundary and a lower boundary of a picture when an interlace signal as a letter box signal is converted into a progressive signal. <P>SOLUTION: An upper and lower boundary determining section 113 determines whether or not an interpolation pixel position P is a pixel position positioned at an upper boundary or a lower boundary on the basis of a determination on whether the interpolation pixel position P is a moving region or a still region and a determination on whether an adjacent pixel position which is adjacent to the upper and lower directions with respect to this interpolation pixel position P is a moving region or a still region with respect to this interpolation pixel position P. When the interpolation pixel position P is a pixel position positioned at the upper boundary and the lower boundary of the image, an interpolation operation circuit 115 generates image data of the interpolation pixel position P using image data of predetermined lines positioned in a predetermined direction (lower direction or upper direction) from the line position respectively corresponding to the interpolation pixel position P. The influence of the pixel data of lines of a non-picture portion (black or dark gray) can be eliminated, and the interpolation pixel position P can be prevented from becoming dark, thereby preventing the occurrence of flickers on the boundary. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image boundary determination apparatus and determination method, and an image signal processing apparatus and processing method using the same.

  Specifically, the present invention determines whether the target pixel position is a motion region or a still region, determines whether an adjacent pixel position adjacent to the target pixel position in a predetermined direction is a motion region or a still region, and When the position is a motion region and the adjacent pixel position is a still region, the target pixel position is determined to be a pixel position located at the boundary of the predetermined direction of the image, so that the target pixel position is the predetermined direction of the image The present invention relates to an image boundary determination device and a determination method that enable a good determination as to whether or not a pixel position is located at the boundary.

  Further, according to the present invention, when the interlace signal is converted into a progressive signal, the interpolation pixel position corresponds to the interpolation pixel position when the interpolation pixel position is a pixel position located at a boundary in a predetermined direction (upward or downward) of the image. An image signal processing apparatus capable of reducing the occurrence of flicker at a boundary by generating pixel data at an interpolated pixel position using pixel data of a predetermined line located in a direction opposite to the predetermined direction from the line position, and It relates to the processing method.

  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. 9, the interlaced signal is composed of two frames, odd and even, each having a line signal 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 IP conversion, generally, a motion detection process is performed to divide a motion region and a static region. As shown in FIG. 10, interpolation data is generated from pixel data of previous and subsequent lines in the same field for the motion region. For the still region, interpolation data is generated from pixel data of the same line in the preceding and following fields (see Patent Document 1).

  In the motion detection process, for example, as shown in FIG. 10, when the interpolation pixel position P is in the field one field before, the data of the pixel d0 in the current field corresponding to this interpolation pixel position P and two fields (1 The difference absolute value of the data of the pixel d1 before the frame) is obtained as frame motion information, and the difference absolute value is compared with a threshold value to determine whether the interpolation pixel position P is a motion region or a still region.

JP 2002-185933 A

  Conventionally, a letterbox method is known as a method for displaying a 16: 9 image on a 4: 3 screen. This letterbox method is a method in which the width of a 16: 9 image is aligned with a 4: 3 screen and the upper and lower portions of the screen are not used. FIG. 11 shows a state in which an image based on an image signal corresponding to letterbox display (hereinafter referred to as “letterbox signal” as appropriate) is displayed on the display screen. In FIG. 11, the hatched portion is a main image portion where an image exists, and the hatched upper and lower portions are non-image portions where no image exists. The non-image area is usually displayed in black or dark gray.

  It can be considered that this letterbox signal is also converted from an interlace signal to a progressive signal, and an image is displayed on the display in a progressive manner. In this case, as described above, the interpolation data is generated from the pixel data of the previous and subsequent lines in the same field for the motion region, and the interpolation data is generated from the pixel data of the same line of the previous and subsequent fields for the still region. However, there is a problem that flicker may occur at the upper boundary and the lower boundary of the image, and the image quality deteriorates.

  Here, the principle of flicker generation will be described with reference to FIG. FIG. 12 is an enlarged view of the vicinity of the upper boundary of the letterbox signal image. The horizontal axis corresponds to the time direction, and the vertical axis corresponds to the vertical direction.

  When the interpolation pixel position P existing in the previous field is determined as the motion region, the average value of the data of the pixels C and M in the lines before and after the line where the interpolation pixel position P exists is the interpolation pixel position. P pixel data Dip. Further, when the interpolation pixel position P is determined to be a still region, the average value of the data of the pixels d0 and d1 in the current field corresponding to the interpolation pixel position P and the previous two fields is the pixel at the interpolation pixel position P. Data Dip.

  As described above, the non-image area is displayed in black or dark gray. When the interpolation pixel position P is determined to be a motion region, the pixel data Dip at the interpolation pixel position P is an average value of the data of the pixel C of the non-image portion and the data of the pixel M of the main image portion as described above. The interpolation pixel position P becomes considerably dark. On the other hand, when the interpolation pixel position P is determined to be a still region, the pixel data Dip at the interpolation pixel position P is the average value of the data of the pixels d0 and d1 in the main picture portion as described above. It should not be particularly dark.

  Therefore, when the determination of the motion region or the still region at the interpolation pixel position P located at the upper boundary of the image varies in each field, the brightness of the interpolation pixel position P changes greatly. Flicker occurs. The same applies to the principle of flicker generation at the lower boundary of the image.

  An object of the present invention is to satisfactorily determine whether or not a target pixel position is a pixel position located at a boundary in a predetermined direction of an image. Another object of the present invention is to prevent the occurrence of flicker at the upper and lower boundaries of an image when an interlace signal is converted into a progressive signal.

  The image boundary determination device according to the present invention is an image boundary determination device that determines whether a target pixel position is a pixel position located at a boundary in a predetermined direction of an image. First motion / stillness determination means for determining using pixel data at a predetermined time position in the time direction corresponding to the pixel position, and an adjacent pixel position adjacent to the target pixel position in the predetermined direction is a motion region or a still region The second movement / stillness determination means for determining whether or not using the pixel data at a predetermined time position in the time direction corresponding to the adjacent pixel position, and the target pixel position in the first movement / stillness determination means And when the second movement / stillness determination means determines that the adjacent pixel position is a still region, the target pixel position is determined to be a pixel position located at a boundary in a predetermined direction of the image. Border In which and a determination unit.

  Further, the image boundary determination method according to the present invention is the image boundary determination method for determining whether the target pixel position is a pixel position located at the boundary in the predetermined direction of the image. A first motion / stillness determination step for determining using pixel data at a predetermined time position in the time direction corresponding to the target pixel position; and whether an adjacent pixel position adjacent to the target pixel position in the predetermined direction is a motion region The pixel position of interest is determined in the second movement / stillness determination step and the first movement / stillness determination step in which determination is made using pixel data at a predetermined time position in the time direction corresponding to the adjacent pixel position. A pixel in which the target pixel position is located at a boundary in a predetermined direction of the image when it is determined that the region is a motion region and the adjacent pixel position is determined to be a still region in the second motion / stillness determination step In which and a determining boundary determination step that the location.

  In the present invention, it is determined whether the target pixel position is a moving region or a still region using pixel data at a predetermined time position in the time direction (field direction or frame direction) corresponding to the target pixel position. For example, a difference absolute value between two pixel data relating to a predetermined time position is obtained, and this difference absolute value is compared with a threshold value, whereby a determination result at the predetermined time position is obtained. In this case, pixel data corresponding to a plurality of time positions in the time direction is used to obtain a plurality of determination results at the plurality of time positions, and when any one of the plurality of determination results indicates a motion region, By determining that the target pixel position is a motion region, it is possible to increase the accuracy of determination that the target pixel position is a motion region.

  Also, whether the adjacent pixel position adjacent to the target pixel position in a predetermined direction (upward, downward, rightward, leftward, etc.) is a moving region or a stationary region is predetermined in the time direction corresponding to the adjacent pixel position. It is determined using the pixel data at the time position. For example, a difference absolute value relating to two pixel positions relating to a predetermined time position is obtained, and the difference absolute value is compared with a threshold value, whereby a determination result at the predetermined time position is obtained. In this case, using pixel data corresponding to a plurality of time positions in the time direction, obtaining a plurality of determination results at the plurality of time positions, and indicating that all of the plurality of determination results are still regions, By determining that is a still region, it is possible to improve the accuracy of determination that this adjacent pixel position is a still region.

  Then, when it is determined that the target pixel position is a motion region and the adjacent pixel position is determined to be a still region, the target pixel position is determined to be a pixel position located at a boundary in a predetermined direction of the image. .

  It is to be noted whether a predetermined number of pixel positions existing in the periphery of the target pixel position in a direction orthogonal to the predetermined direction are each a moving region or a stationary region, and a predetermined time in a time direction corresponding to the predetermined number of pixel positions. A third motion / stillness determination unit that determines using the pixel data of the position, and the boundary determination unit determines that the target pixel position is a motion region by the first movement / stillness determination unit; or When any of the predetermined number of pixel positions is determined to be a motion region by the third motion / stillness determination means, and the adjacent pixel position is determined to be a still region by the second motion / stillness determination means Alternatively, it may be determined that the target pixel position is a pixel position located at a boundary in a predetermined direction of the image. By confirming that the predetermined number of pixel positions are all motion regions by the third motion / stillness determination means, it is possible to make sure that the pixel position of interest is a motion region. The accuracy of the determination that the pixel position is located at the boundary in the predetermined direction of the image can be further increased.

  In addition, a predetermined time in a time direction corresponding to each of the predetermined number of pixel positions is determined as to whether the predetermined number of pixel positions existing in the vicinity of the adjacent pixel position in the direction orthogonal to the predetermined direction is a moving region or a stationary region. Fourth movement / stillness determination means for determining using the pixel data of the position is further provided, and the boundary determination means is determined by the first movement / stillness determination means that the target pixel position is a motion region, and second When the adjacent pixel position is determined to be a still region by the movement / stillness determination means, and when the predetermined number of pixel positions are all determined to be a still region by the fourth movement / stillness determination means, the target pixel position is You may make it determine with it being a pixel position located in the boundary of the predetermined direction of an image. By confirming that the predetermined number of pixel positions are all still areas by the fourth movement / stillness determining means, it is possible to make it more certain that the adjacent pixel positions are still areas. The accuracy of the determination that the pixel position is located at the boundary in the predetermined direction of the image can be further increased.

  An image signal processing apparatus according to the present invention is an image signal processing apparatus that converts an interlace signal into a progressive signal, and has an interpolation pixel position at a boundary in a predetermined direction that is an upward direction or a downward direction orthogonal to the line direction of the image. A boundary determination unit that determines whether the pixel position is located, and a pixel data generation unit that generates pixel data at the interpolation pixel position based on a determination result of the boundary determination unit. When it is determined that the interpolation pixel position is a pixel position located at the boundary, the interpolation pixel is detected using pixel data of a predetermined line located in a direction opposite to the predetermined direction from the line position corresponding to the interpolation pixel position. The pixel data of the position is generated.

  The image signal processing method according to the present invention is an image signal processing method for converting an interlace signal into a progressive signal, wherein the interpolation pixel position is in a predetermined direction that is an upward direction or a downward direction orthogonal to the line direction of the image. A boundary determination step for determining whether the pixel position is located at the boundary, and a pixel data generation step for generating pixel data at the interpolation pixel position based on the determination result of the boundary determination step. In the pixel data generation step, When it is determined in the boundary determination step that the interpolation pixel position is a pixel position located at the boundary, pixel data of a predetermined line positioned in a direction opposite to the predetermined direction from the line position corresponding to the interpolation pixel position is used. Pixel data at the interpolation pixel position is generated.

  In the present invention, the interlace signal is converted into a progressive signal. It is determined whether the interpolated pixel position of the interlace signal is a pixel position located at a boundary in a predetermined direction that is an upward direction or a downward direction orthogonal to the line direction of the image. This determination is performed, for example, by the above-described image boundary determination device. In this case, the interpolation pixel position becomes the target pixel position.

  Based on the determination result, pixel data of the interpolation pixel position is generated. That is, when it is determined that the interpolation pixel position is a pixel position located at the boundary, the interpolation pixel is obtained by using pixel data of a predetermined line located in a direction opposite to the predetermined direction from the line position corresponding to the interpolation pixel position. Pixel data for the position is generated.

  For example, when the interlace signal is a letterbox signal, when the interpolation pixel position is at a pixel position located at the upper boundary or lower boundary of the image, the non-image portion (black If the pixel data of the interpolation pixel position is generated using the pixel data of the (dark gray) line, the interpolation pixel position becomes considerably dark, flicker occurs at this boundary, and the image quality deteriorates.

  However, in the present invention, when it is determined that the interpolation pixel position is a pixel position located at the boundary, pixel data of a predetermined line located in a direction opposite to the predetermined direction from the line position corresponding to the interpolation pixel position is used. The pixel data of the interpolation pixel position is generated, the influence of the pixel data of the non-image portion line can be eliminated, the interpolation pixel position is not darkened, and the occurrence of flicker at the above-described boundary can be prevented, The image quality can be improved.

  For example, the pixel data of the interpolation pixel position includes the first pixel data of the pixels in the line adjacent in the direction opposite to the predetermined direction corresponding to the interpolation pixel position, and the second pixel of the previous field corresponding to the interpolation pixel position. Among the third pixel data of the pixel in the field after corresponding to the pixel data and the interpolation pixel position, the pixel data is the median value. This is a method called a median filter. By this method, a natural value can be obtained as pixel data at the interpolated pixel position regardless of whether the interpolated pixel position is a motion region or a still region.

  When it is determined that the interpolation pixel position is not a pixel position located at the boundary, the pixel data of the interpolation pixel position is generated based on, for example, a determination result of whether the interpolation pixel position is a motion area or a still area. That is, when the interpolation pixel position is determined to be a motion area, the pixel data at the interpolation pixel position is generated using at least the upper line or lower line pixel data with respect to the interpolation pixel position, and the interpolation pixel position is a still area. Is determined using pixel data of at least the previous field or the subsequent field with respect to the interpolation pixel position.

  According to the present invention, it is determined whether the target pixel position is a motion region or a still region, and it is determined whether an adjacent pixel position adjacent to the target pixel position in a predetermined direction is a motion region or a still region. Is a moving region and the adjacent pixel position is a still region, it is determined that the target pixel position is a pixel position located at a boundary in a predetermined direction of the image, and the target pixel position is a predetermined direction of the image. It is possible to satisfactorily determine whether or not the pixel position is located at the boundary.

  Further, according to the present invention, when the interlace signal is converted into the progressive signal, the interpolation pixel position is set to the interpolation pixel position when the interpolation pixel position is a pixel position located at a boundary in a predetermined direction (upward or downward) of the image. The pixel data of the interpolation pixel position is generated using the pixel data of the predetermined line located in the direction opposite to the predetermined direction from the corresponding line position, and the occurrence of flicker at the boundary can be reduced and the image quality is improved. be able to.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a configuration of an image display apparatus 100 as an embodiment.

  The image display apparatus 100 includes an input terminal 101 that inputs an image signal V0 that is an interlace signal, and an IP conversion unit 102 that converts the image signal V0 from an interlace signal to an image signal Vp that is a progressive signal. ing. A memory (storage element) 103 is connected to the IP conversion unit 102.

  The IP conversion unit 102 determines whether or not the interpolation pixel position of the image signal V0 is a pixel position located at a boundary in a predetermined direction that is an upper direction or a lower direction orthogonal to the line direction of the image, and the interpolation Based on the determination result of whether the pixel position is a motion region or a still region, pixel data at the interpolation pixel position is generated, and the image signal V0 is converted into an image signal Vp. The memory 103 has a storage capacity capable of storing pixel data for a predetermined field used in the IP conversion unit 102.

  Further, the image display apparatus 100 drives the PDP 106 based on a PDP (Plasma Display Panel) 106 as a display and an image signal Vp obtained by the IP conversion unit 102, and displays an image based on the image signal Vp on the screen of the PDP 106. And a panel driver 105 for displaying.

  The operation of the image display apparatus 100 shown in FIG. 1 will be described. An image signal V 0 as an interlace signal is supplied to the input terminal 101, and this image signal V 0 is supplied to the IP conversion unit 102. In the IP conversion unit 102, the image signal V0 that is an interlace signal is converted into an image signal Vp that is a progressive signal. The image signal Vp obtained by the IP conversion unit 102 is supplied to the panel driver 105. The panel driver 105 drives the PDP 106 based on the image signal Vp. As a result, an image based on the image signal Vp is displayed on the screen of the PDP 106.

Next, details of the IP conversion unit 102 will be described. FIG. 2 shows the configuration of the IP conversion unit 102.
The IP conversion unit 102 includes a writing processing unit 111 for writing the image signal V0 of the current field into the memory 103, and a reading processing unit 112 for reading the image signal of the past predetermined field from the memory 103. .

  In addition, the IP conversion unit 102 includes an upper and lower boundary determination unit 113 that constitutes first and second movement / stillness determination means and boundary determination means. The upper and lower boundary determination unit 113 determines whether or not the interpolation pixel position P as the target pixel position is a pixel position located on the upper boundary of an image (for example, a main image part (see FIG. 11) based on a letterbox signal). The result JGU and the determination result JGD of whether or not the pixel position is located at the lower boundary of the image are acquired.

  The upper / lower boundary determination unit 113 determines whether the interpolation pixel position P is a motion region or a still region, and a pixel at a predetermined time position in the time direction read from the memory 103 by the processing unit 112 corresponding to the interpolation pixel position. Judgment is made using the data. In this case, the difference absolute value of the two pixel data relating to the predetermined time position is obtained, and the determination result at the predetermined time position is obtained by comparing the difference absolute value with a threshold value.

That is, as shown in FIG. 3, the upper / lower boundary determination unit 113 obtains a difference absolute value D ₀₁ between the data of the pixel d0 in the current field corresponding to the interpolation pixel position P and the data of the pixel d1 two fields before, and this The difference absolute value D ₀₁ is compared with a predetermined threshold value TH to obtain a determination result RS1 at the time position t1 corresponding to the interpolation pixel position P. In this case, when D ₀₁ ≧ TH, it is determined as a motion region, and when D ₀₁ <TH, it is determined as a still region.

  Although this determination result RS1 can be used as a final determination result as it is, in the present embodiment, the upper and lower boundary determination unit 113 further obtains determination results RS2 to RSm at time positions t2 to tm, and these determination results Based on RS1 to RSm, a final determination result RSp is obtained as to whether the interpolation pixel position P is a motion region or a still region. In this case, the determination result RSp indicates the still region when it is determined that all of the determination results RS1 to RSm at the continuous m time positions t1 to tm are still regions, and otherwise. Indicates a motion region.

This determination result RSp can be expressed by the following logical expression. However, it is assumed that each of the determination results RS1 to RSm and RSp is “1” when indicating a stationary region and “0” when indicating a motion region. In this expression, “==” represents a logical equal sign, and “&&” represents a logical product.
RSp == RS1 && RS2 && RS3 && ... && RSm (1)

Here, the determination result RS2 at time position t2, calculates a difference absolute value D ₁₂ of the data in the data and four fields previous pixel d2 of two fields before the pixel d1 corresponding to the interpolation pixel position P, and the absolute difference obtained by comparing with a predetermined threshold value TH which is previously determined to D _12. Similarly, the determination result RS3 at time position t3, determines the difference absolute value D ₂₃ of the data in the data and 6 fields preceding pixel d3 pixel d2 before four fields corresponding to the interpolation pixel position P, and the absolute difference obtained by comparing a predetermined threshold TH that is determined to D ₂₃ in advance. Hereinafter, determination results RS4 to RSm at time positions t4 to tm are obtained in the same manner.

  Of the determination results RS1 to RSm described above, the determination results RS2 to RSm are used as the determination results RS1 to RSm-1 in the determination process of the upper and lower boundaries one frame before. Therefore, the upper and lower boundary determination unit 113 stores the determination results RS1 to RSm-1 used in the determination processing of the upper and lower boundaries one frame before in a memory (not shown), thereby obtaining the determination results RS1 to RS1. It can be used as RSm. In this case, if only the determination result RS1 is acquired, the upper and lower boundary determination unit 113 can obtain the final determination result RSp whether the interpolation pixel position P is a motion region or a still region.

  Further, the upper / lower boundary determination unit 113 determines whether the adjacent pixel positions Pu and Pd adjacent in the upward and downward directions with respect to the interpolation pixel position P correspond to the adjacent pixel positions Pu and Pd. The determination is made using pixel data at a predetermined time position in the time direction. In this case, the difference absolute value of the two pixel data relating to the predetermined time position is obtained, and the determination result at the predetermined time position is obtained by comparing the difference absolute value with a threshold value.

That is, for the adjacent pixel position Pu adjacent in the upward direction, the upper and lower boundary determination unit 113, as shown in FIG. 3, the data of the pixel e0 one field before corresponding to the adjacent pixel position Pu and the pixel three fields before The absolute difference value E ₀₁ of the data of e ₁ is obtained, and this absolute difference value E ₀₁ is compared with a predetermined threshold value TH to obtain the determination result RSu 1 at the time position t 1 corresponding to the adjacent pixel position Pu. obtain. In this case, when E ₀₁ ≧ TH, it is determined as a motion region, and when E ₀₁ <TH, it is determined as a still region.

  Although this determination result RSu1 can be used as a final determination result as it is, in the present embodiment, the upper and lower boundary determination unit 113 further obtains determination results RSu2 to RSum at time positions t2 to tm, and these determination results Based on RSu1 to RSum, a final determination result RSup is obtained as to whether the adjacent pixel position Pu is a motion region or a still region. In this case, the determination result RSup indicates the still region when it is determined that all of the determination results RSu1 to RSum at the consecutive m time positions t1 to tm are the still region, and otherwise. Indicates a motion region.

This determination result RSup can be expressed by the following logical expression. However, it is assumed that each of the determination results RSu1 to RSum, RSup is “1” when indicating a stationary region and “0” when indicating a motion region. In this expression, “==” represents a logical equal sign, and “&&” represents a logical product.
RSup == RSu1 && RSu2 && RSu3 && ... && RSum (2)

Here, the determination result RSu2 at time position t2, calculates a difference absolute value E ₁₂ of data of the data and 5 field preceding pixel e2 pixels e1 before three fields corresponding to adjacent pixel positions Pu, and the difference absolute value It is obtained by comparing E ₁₂ with a predetermined threshold TH. Similarly, the determination result RSu3 at time position t3, calculates a difference absolute value E ₂₃ of the data in the data and 7 previous field pixel e3 pixel e2 before five fields corresponding to adjacent image position Pu, and the difference absolute value obtained by comparing a predetermined threshold TH that is determined in advance E _23. Hereinafter, determination results RSu4 to RSum at time positions t4 to tm are obtained in the same manner.

  The determination results RSu1 to RSum described above are used as the determination results RS1 to RSm in the determination process of the upper and lower boundaries of the interpolation pixel position P ′ of the previous field. Therefore, the upper and lower boundary determination unit 113 stores the determination results RS1 to RSm used in the determination process of the upper and lower boundaries of the interpolated pixel position P ′ in a memory (not shown), so that the determination results RSu1 to It can be used as RSum.

Further, as shown in FIG. 3, the upper / lower boundary determination unit 113, for the adjacent pixel position Pd adjacent in the downward direction, the data of the pixel f0 one field before and the pixel three fields before corresponding to the adjacent pixel position Pd. The absolute difference value F ₀₁ of the data of f ₁ is obtained, and this absolute difference value F ₀₁ is compared with a predetermined threshold value TH to obtain the determination result RSd 1 at the time position t 1 corresponding to the adjacent pixel position Pd. obtain. In this case, when F ₀₁ ≧ TH, it is determined as a motion region, and when F ₀₁ <TH, it is determined as a still region.

  Although this determination result RSd1 can be used as a final determination result as it is, in this embodiment, the upper and lower boundary determination unit 113 further obtains determination results RSd2 to RSdm at time positions t2 to tm, and these determination results Based on RSd1 to RSdm, a final determination result RSdp is obtained as to whether the adjacent pixel position Pd is a motion region or a still region. In this case, the determination result RSdp indicates the still region when it is determined that all of the determination results RSd1 to RSdm at the consecutive m time positions t1 to tm are the still region, and otherwise. Indicates a motion region.

This determination result RSdp can be expressed by the following logical expression. However, it is assumed that each of the determination results RSd1 to RSdm, RSdp is “1” when indicating a stationary region and “0” when indicating a motion region. In this expression, “==” represents a logical equal sign, and “&&” represents a logical product.
RSdp == RSd1 && RSd2 && RSd3 && ... && RSdm (3)

Here, the determination result RSd2 at time position t2, calculates a difference absolute value F ₁₂ of the data in the data and 5 field preceding pixel f2 of the pixel f1 before three fields corresponding to adjacent pixel positions Pd, and the difference absolute value It is obtained by comparing F ₁₂ with a predetermined threshold TH. Similarly, the determination result RSd3 at time position t3, calculates a difference absolute value F ₂₃ of the data of the data and 7 previous field pixel f3 pixel f2 before five fields corresponding to adjacent image position Pd, and the difference absolute value obtained by comparing a predetermined threshold TH that is determined to F ₂₃ in advance. Hereinafter, determination results RSd4 to RSdm at time positions t4 to tm are obtained in the same manner.

  The above-described determination results RSd1 to RSdm are used as the determination results RS1 to RSm in the determination process of the upper and lower boundaries of the interpolation pixel position P ″ of the previous field. By storing the determination results RS1 to RSm used in the determination process of the upper and lower boundaries of P ″ in a memory (not shown), it can be used as the determination results RSd1 to RSdm.

  M described above is an arbitrary number equal to or greater than 2, and the determination accuracy can be increased as m increases. However, as m becomes larger, when the target pixel position changes from the motion region to the still region, the time until obtaining a determination result that the target pixel is the still region becomes longer, and the responsiveness becomes worse.

  The upper / lower boundary determination unit 113 performs interpolation based on the determination result RSp whether the interpolation pixel position P is the motion region or the still region and the determination result RSup whether the adjacent pixel position Pu adjacent in the upward direction is the motion region or the still region. It can be determined whether or not the pixel position P is a pixel position located at the upper boundary of the image. In this case, when the determination result RSp indicates a motion region and the determination result RSup indicates that it is a still region, it is determined that the interpolation pixel position P is a pixel position located at the upper boundary of the image.

  Further, the upper and lower boundary determination unit 113 is based on the determination result RSp whether the interpolation pixel position P is the motion region or the still region and the determination result RSdp whether the adjacent pixel position Pd adjacent in the downward direction is the motion region or the still region. It can be determined whether or not the interpolation pixel position P is a pixel position located at the lower boundary of the image. In this case, when the determination result RSp indicates a motion region and the determination result RSup indicates a still region, it is determined that the interpolation pixel position P is a pixel position located at the lower boundary of the image.

  In the present embodiment, the upper and lower boundary determination unit 113, in order to make the determination that the interpolation pixel position P is a motion region more reliable, in the same way as the interpolation pixel position P, Further, determination results RSp1 to RSpn indicating whether a predetermined number n of pixel positions (G, I, F, J, etc.) existing around the line direction orthogonal to the vertical direction are a motion region or a static region are further acquired. Since the method for obtaining the determination results RSp1 to RSpn is the same as the method for obtaining the determination result RSp at the interpolation pixel position P described above, the description thereof is omitted here.

Further, in the present embodiment, the upper / lower boundary determination unit 113 determines the upper adjacent pixel position Pu as a still region, in order to make the determination that the upper adjacent pixel position Pu is a still region, as well as the adjacent pixel position Pu. pixel position Pu, a pixel position of a predetermined number n _U existing around the line direction perpendicular to the vertical direction (B, D, a, E, etc.) determination result RSup1～RSupn _U indicating whether region or a still region motion To get more. The method for acquiring the determination result RSup1～RSupn _U is the same as the method for obtaining the determination result RSup in the interpolation pixel position Pu described above and the description thereof will be omitted.

Further, in the present embodiment, the upper / lower boundary determination unit 113 determines the adjacent pixel position Pd in the downward direction as the adjacent pixel position Pd in order to make the determination that the adjacent pixel position Pd in the downward direction is a still region. Determination results RSdp1 to RSdpn _D indicating whether a predetermined number n _D of pixel positions (L, N, K, O, etc.) existing around the pixel direction Pd in the line direction orthogonal to the up-down direction are a motion region or a still region. To get more. The method for acquiring the determination results RSdp1 to RSdpn _{D is the same as} the method for acquiring the determination result RSdp at the interpolation pixel position Pd described above, and thus the description thereof is omitted here.

After all, in the present embodiment, the upper / lower boundary determination unit 113 determines the determination result RSp of the interpolation pixel position P, the determination results RSp1 to RSpn of the predetermined number n of pixel positions around the interpolation pixel value P, and the adjacent pixel position. based on the determination result RSup1～RSupn _U pixel position of a predetermined number n _U existing around the Pu determination result RSup and the neighboring pixel position Pu, whether the interpolation pixel position P is a pixel position located image on the boundary Judgment result JGU is obtained. In this case, when at least one of the determination results RSp and RSp1 to RSpn is a motion region, and all of the determination results RSup and RSup1 to RSupn _U are still regions, the interpolation pixel position P is on the image. It is determined that the pixel position is located at the boundary, and otherwise, it is determined that the interpolation pixel position P is not a pixel position located at the upper boundary of the image.

In the present embodiment, the upper and lower boundary determination unit 113 also determines the determination result RSp of the interpolation pixel position P, the determination results RSp1 to RSpn of a predetermined number n of pixel positions around the interpolation pixel value P, and the adjacent pixel position. based on the determination result RSdp1～RSdpn _D pixel position of a predetermined number n _D existing around the Pd determination result RSdp and the neighboring pixel position Pd, or the interpolation pixel position P is a pixel position located below the image boundary Judgment result JGD is obtained. In this case, when at least one of the determination results RSp and RSp1 to RSpn is a motion region, and all of the determination results RSdp and RSdp1 to RSdpn _D are still regions, the interpolation pixel position P is below the image. It is determined that the pixel position is located at the boundary. Otherwise, it is determined that the interpolation pixel position P is not a pixel position located at the lower boundary of the image.

Note that n, n _U , and n _D described above are each an arbitrary number of 1 or more, and may be the same number or different numbers.

The IP conversion unit 102 illustrated in FIG. 2 includes a movement / stillness determination unit 114. The motion / stillness determination unit 114 determines whether the interpolated pixel position P existing in the previous field is a motion region or a still region, using the image signal V0 of the current field and the image signal V2 of the previous field. . That is, as shown in FIG. 3, the motion / stillness determination unit 114 obtains a difference absolute value D ₀₁ between the data of the pixel d0 in the current field corresponding to the interpolation pixel position P and the data of the pixel d1 two fields before, and this The difference absolute value D ₀₁ is compared with a predetermined threshold value TH to obtain a determination result JGM. In this case, when D ₀₁ ≧ TH, it is determined as a motion region, and when D ₀₁ <TH, it is determined as a still region.

  The determination result JGM is the same as the determination result RS1 in the above-described upper and lower boundary determination unit 113 whether the interpolation pixel position P is a motion region or a still region. Therefore, regarding the determination result JGM, the determination result RS1 obtained by the upper and lower boundary determination unit 113 may be used without providing the movement / stillness determination unit 114.

  The IP conversion unit 102 includes a motion adaptive interpolation calculation circuit 115. The interpolation calculation circuit 115 generates pixel data Dip of the interpolation pixel position P based on the determination results JGU and JGD obtained by the upper and lower boundary determination unit 113 and the determination result JGM obtained by the motion / stillness determination unit 114. .

  The interpolation calculation circuit 115 indicates that the determination result JGU indicates that the interpolation pixel position P is not a pixel position positioned at the upper boundary of the image, and the determination result JGD indicates that the interpolation pixel position P is not a pixel position positioned at the lower boundary of the image. At this time, the pixel data Dip of the interpolation pixel position P is generated based on the determination result JGM.

  That is, when the determination result JGM indicates a motion region, the interpolation calculation circuit 115 generates pixel data Dip using at least the upper line or lower line pixel data with respect to the interpolation pixel position P, and the determination result JGM is stationary. When an area is indicated, pixel data Dip is generated using pixel data of at least the previous field or the subsequent field with respect to the interpolation pixel position P.

  For example, when the determination result JGM indicates the motion region, the interpolation calculation circuit 115 calculates the average value of the data of the pixels e0 and f0 of the lines before and after the line where the interpolation pixel position P exists as shown in FIG. 5A. When the data Dip is one and the determination result JGM indicates a still region, as shown in FIG. 5A, the average value of the data d0 and d1 of the current field corresponding to the interpolation pixel position P and the pixels d0 and d1 in the previous two fields is displayed. The data is Dip.

  In addition, when the determination result JGU indicates that the interpolation pixel position P is a pixel position located at the upper boundary of the image, the interpolation calculation circuit 115 determines a predetermined position that is located downward from the line position corresponding to the interpolation pixel position P. The pixel data Dip of the interpolation pixel position P is generated using the line pixel data.

  For example, as illustrated in FIG. 5B, the interpolation calculation circuit 115 corresponds to the interpolation pixel position P, the first pixel data of the pixel f0 of the line adjacent in the downward direction, and the previous field corresponding to the interpolation pixel position P. Of the second pixel data of the pixel d1 and the third pixel data of the pixel d0 in the field corresponding to the interpolation pixel position P, the pixel data of the median value is set as the pixel data Dip of the interpolation pixel position P. The method of taking the median value in this way is a method called a median filter. With this method, a natural value can be obtained as the pixel data Dip regardless of whether the interpolation pixel position P is a motion region or a still region.

  In this case, an average value or the like of the first to third pixel data may be obtained as the pixel data Dip at the interpolation pixel position P. Further, the average value of the pixel data of the pixels d0 and d1, or the pixel data of the pixel f0 may be used as the pixel data Dip of the interpolation pixel position P.

  In addition, when the determination result JGD indicates that the interpolation pixel position P is a pixel position located at the lower boundary of the image, the interpolation calculation circuit 115 determines a predetermined line positioned upward from the line position corresponding to the interpolation pixel position P. Is used to generate pixel data Dip at the interpolated pixel position P.

  For example, as illustrated in FIG. 5C, the interpolation calculation circuit 115 corresponds to the interpolation pixel position P, the first pixel data of the pixel e0 on the line adjacent in the upward direction, and the previous field corresponding to the interpolation pixel position P. Of the second pixel data of the pixel d1 and the third pixel data of the pixel d0 in the field corresponding to the interpolation pixel position P, the pixel data of the median value is set as the pixel data Dip of the interpolation pixel position P. Also in this case, as described above, the method is called a median filter, and a natural value can be obtained as the pixel data Dip regardless of whether the interpolation pixel position P is a motion region or a still region.

  In this case as well, an average value or the like of the first to third pixel data may be obtained as the pixel data Dip at the interpolation pixel position P. Further, the average value of the pixel data of the pixels d0 and d1, or the pixel data of the pixel e0 may be used as the pixel data Dip of the interpolation pixel position P.

  The interpolation calculation circuit 115 generates pixel data Dip based on the determination results JGU, JGD, and JGM as described above at each interpolation pixel position P on each interpolation line in the vertical direction, and sequentially outputs the signal of each interpolation line. Generate.

  The IP conversion unit 102 alternately takes out the signal of each line of the image signal V1 one field before read from the memory 103 by the read processing unit 112 and the signal of each interpolation line generated by the interpolation calculation circuit 115. Output line selection circuit 116 for obtaining an image signal Vp which is a progressive signal.

The operation of the IP conversion unit 102 shown in FIG. 2 will be described.
An image signal (image signal in the current field) V0 as an interlace signal is supplied to the memory 103 via the write processing unit 111 and written therein. Then, the read processing unit 112 reads the image signal of the past predetermined field used by the upper / lower boundary determination unit 113, the motion / stillness determination unit 114, and the motion adaptive interpolation calculation circuit 115 from the memory 103.

  In the upper / lower boundary determination unit 113, based on the image signal V0 in the current field and the image signal in the past predetermined field, the interpolation pixel position P existing in the previous field is a pixel position positioned at the upper boundary of the image. Whether or not the pixel position is located at the lower boundary of the image is determined.

  In this case, the upper and lower bound determination unit 113 determines whether the interpolation pixel position P is a motion region or a still region, and a determination result RSp is obtained. This determination result RSp indicates a still area when it is determined that all of the determination results RS1 to RSm at m consecutive time positions t1 to tm are still areas, and otherwise moves. An area is indicated.

  In addition, the upper and lower boundary determination unit 113 determines whether adjacent pixel positions Pu and Pd that are adjacent in the upward and downward directions with respect to the interpolation pixel position P are motion areas or still areas, and obtains determination results RSup and RSdp. These determination results RSup and RSdp indicate a still region when it is determined that all of the determination results RSu1 to RSum and RSd1 to RSdm at m consecutive time positions t1 to tm are still regions. In other cases, the motion area is indicated.

In addition, in order to make the determination that the interpolation pixel position P is a motion region in the vertical boundary determination unit 113, the vertical direction of the interpolation pixel position P is similar to the interpolation pixel position P. Determination results RSp1 to RSpn indicating whether a predetermined number n of pixel positions existing around the orthogonal line direction are the motion region or the still region are obtained. Similarly, in order to make the determination that the adjacent pixel positions Pu and Pd are still regions in the upper and lower boundary determination unit 113, the adjacent pixel positions Pu and Pd are similar to the adjacent pixel positions Pu and Pd. of pd, the predetermined number n _U which is the vertical direction exists around the line direction perpendicular, n _D determination result RSup1～RSupn _U indicating whether pixel positions are moving area or a still region of, RSdp1~RSdpn _D is obtained.

Then, the upper and lower boundary determination unit 113 determines the determination result RSp of the interpolation pixel position P, the determination results RSp1 to RSpn of a predetermined number n of pixel positions around the interpolation pixel value P, the determination result RSup of the adjacent pixel position Pu, the determination result of the pixel positions of a predetermined number n _U existing around the adjacent pixel position Pu based on Sup1~RSupn _U, whether the interpolation pixel position P is a pixel position located on the image boundary determination result JGU Is obtained. In this case, when at least one of the determination results RSp and RSp1 to RSpn is a motion region, and all of the determination results RSup and RSup1 to RSupn _U are still regions, the interpolation pixel position P is on the image. It is determined that the pixel position is located at the boundary. Otherwise, it is determined that the interpolation pixel position P is not a pixel position located at the upper boundary of the image.

In addition, the upper / lower boundary determination unit 113 determines the determination result RSp of the interpolation pixel position P, the determination results RSp1 to RSpn of a predetermined number n of pixel positions around the interpolation pixel value P, the determination result RSdp of the adjacent pixel position Pd, and Based on the determination results Sdp1 to RSdpn _D of the predetermined number n _D existing around the adjacent pixel position Pd, the determination result JGD whether or not the interpolation pixel position P is a pixel position located at the lower boundary of the image Is obtained. In this case, when at least one of the determination results RSp and RSp1 to RSpn is a motion region, and all of the determination results RSdp and RSdp1 to RSdpn _D are still regions, the interpolation pixel position P is below the image. It is determined that the pixel position is located at the boundary. Otherwise, it is determined that the interpolation pixel position P is not a pixel position located at the lower boundary of the image.

  The motion / stillness determination unit 114 determines whether the interpolated pixel position P existing in the previous field is based on the image signal V0 of the current field and the image signal V2 of the previous field by the motion region or the still region. The result JGM is obtained.

  The determination results JGU and JGD obtained by the upper and lower boundary determination unit 113 and the determination result JGM obtained by the motion / stillness determination unit 114 are supplied to the motion adaptive interpolation calculation circuit 115. The interpolation calculation circuit 115 is supplied with the image signal V0 of the current field, the image signal V1 of the previous field read from the memory 103, and the image signal V2 of the previous field. In the interpolation calculation circuit 115, pixel data Dip at the interpolation pixel position P is generated based on the determination results JGU, JGD, and JGM.

  In the interpolation calculation circuit 115, the determination result JGU indicates that the interpolation pixel position P is not a pixel position positioned at the upper boundary of the image, and the determination result JGD indicates that the interpolation pixel position P is not a pixel position positioned at the lower boundary of the image. When shown, the pixel data Dip of the interpolation pixel position P is generated based on the determination result JGM.

  In this case, in the interpolation calculation circuit 115, when the determination result JGM indicates a motion region, pixel data Dip is generated using pixel data of at least the upper line or the lower line with respect to the interpolation pixel position P, and the determination result JGM is When a static region is indicated, pixel data Dip is generated using pixel data of at least the previous field or the subsequent field with respect to the interpolation pixel position P. For example, in the interpolation calculation circuit 115, when the determination result JGM indicates a motion region, the average value of the data of the pixels e0 and f0 in the lines before and after the line where the interpolation pixel position P exists is set as the pixel data Dip. When the result JGM indicates a static region, the average value of the data of the pixels d0 and d1 in the current field corresponding to the interpolation pixel position P and the two fields before the line is set as the pixel data Dip (see FIG. 5A).

  Further, in the interpolation calculation circuit 115, when the determination result JGU indicates that the interpolation pixel position P is a pixel position located at the upper boundary of the image, a predetermined position located downward from the line position corresponding to the interpolation pixel position P is determined. Pixel data Dip at the interpolation pixel position P is generated using the pixel data of the line. For example, in the interpolation calculation circuit 115, the first pixel data of the pixel f0 of the line adjacent in the downward direction corresponding to the interpolation pixel position P, the second pixel of the pixel d1 of the previous field corresponding to the interpolation pixel position P Of the third pixel data of the pixel d0 in the field after corresponding to the data and the interpolation pixel position P, the median pixel data is set as the pixel data Dip of the interpolation pixel position P (see FIG. 5B).

  Further, in the interpolation calculation circuit 115, when the determination result JGD indicates that the interpolation pixel position P is a pixel position located at the lower boundary of the image, the line located upward from the line position corresponding to the interpolation pixel position P The pixel data Dip of the interpolation pixel position P is generated using the pixel data. For example, in the interpolation calculation circuit 115, the first pixel data of the pixel e0 of the line adjacent in the upward direction corresponding to the interpolation pixel position P, the second pixel of the pixel d1 of the previous field corresponding to the interpolation pixel position P Of the third pixel data of the pixel d0 in the field after corresponding to the data and the interpolation pixel position P, the median pixel data is set as the pixel data Dip of the interpolation pixel position P (see FIG. 5C).

  In the interpolation calculation circuit 115, pixel data Dip is generated as described above at each interpolation position on each interpolation line in the vertical direction, and signals for each interpolation line are sequentially generated. Thus, the signal of each interpolation line generated by the interpolation calculation circuit 115 is supplied to the output line selection circuit 116. The output line selection circuit 116 is supplied with the signal of each line of the image signal V1 one field before read from the memory 103. In the output line selection circuit 116, the signal of each line of the image signal V1 of the previous field and the signal of each interpolation line corresponding thereto are taken out alternately, the number of lines is doubled, and the image signal Vp which is a progressive signal. Is obtained. This image signal Vp becomes an output signal of the IP conversion unit 102.

  According to the upper and lower boundary determination unit 113 in the IP conversion unit 102 shown in FIG. 2, it is determined whether the interpolation pixel position P is a motion region or a still region, and is adjacent to the interpolation pixel position P in the upward direction and the downward direction. It is determined whether the adjacent pixel positions Pu and Pd are motion areas or still areas. When the interpolation pixel position P is a motion area and the adjacent pixel positions Pu and Pd are still areas, this interpolation pixel position P is It is determined that the pixel position is located at the boundary between the direction and the lower direction, and it can be satisfactorily determined whether or not the interpolation pixel position P is a pixel position located at the boundary between the upper direction and the lower direction of the image.

  Further, in this case, according to the upper and lower boundary determination unit 113, determination results RS1 to RSm at a plurality of time positions t1 to tm in the time direction corresponding to the target pixel position P are obtained, and the interpolation pixel position is based on the determination results. The determination result RSp whether P is a motion region or a still region is obtained (see FIG. 3), and the determination accuracy of whether the interpolation pixel position P is a motion region or a still region can be improved. Similarly, the upper and lower boundary determination unit 113 obtains determination results RSu1 to RSum and RSd1 to RSdm at a plurality of time positions t1 to tm in the time direction corresponding to the adjacent pixel positions Pu and Pd, and based on the determination results. Thus, determination results RSup and RSdp for determining whether adjacent pixel positions Pu and Pd are motion regions or still regions are obtained (see FIG. 3), and the determination accuracy for determining whether adjacent pixel positions Pu and Pd are motion regions or still regions is improved. be able to.

Further, in this case, according to the upper / lower boundary determination unit 113, similarly to the interpolation pixel position P, a predetermined number n of pixel positions present around the interpolation pixel position P in the line direction orthogonal to the vertical direction are the motion region. Determination results RSp1 to RSpn indicating whether the pixel is a still region or not, and, similarly to the adjacent pixel positions Pu and Pd, a predetermined number n existing around the adjacent pixel positions Pu and Pd in the line direction orthogonal to the vertical direction _U, n _D determination result RSup1～RSupn _U of pixel positions indicating whether motion region or a still region of, give RSdp1～RSdpn _D, the determination result using even these JGU, is intended to obtain a JGD (see FIG. 4) , The determination that the interpolated pixel position P is a motion region can be made more reliable, and the determination that the adjacent pixel positions Pu and Pd are still regions can be made more reliable, and the determination results JGU and JGD Increase accuracy It is possible.

  Further, according to the motion adaptive interpolation calculation circuit 115 in the IP conversion unit 102 shown in FIG. 2, the determination results JGU and JGD indicate that the interpolation pixel position P is a pixel position located at the upper boundary and the lower boundary of the image. In this case, the pixel data Dip of the interpolation pixel position P is generated using pixel data of a predetermined line located in a predetermined direction (downward or upward) from the line position corresponding to the interpolation pixel position P. For example, when the interlace signal is a letterbox signal, it is possible to eliminate the influence of pixel data of a non-image portion (black or dark gray) line located on the predetermined direction side with respect to the interpolation pixel position P, and the interpolation pixel position P Is not darkened, flickering at the above-described boundary can be prevented, and image quality can be improved.

  In this case, according to the interpolation calculation circuit 115, the first pixel data of the pixels f0 and e0 of the line adjacent to the direction opposite to the predetermined direction corresponding to the interpolation pixel position P, the previous pixel data corresponding to the interpolation pixel position P are detected. Of the second pixel data of the pixel d1 in the field and the third pixel data of the pixel d0 in the field after corresponding to the interpolation pixel position P, the pixel data Dip of the interpolation pixel position P is the median pixel data. Therefore, a natural value can be obtained as the pixel data Dip of the interpolation pixel position P regardless of whether the interpolation pixel position P is a motion region or a still region.

  Note that the processing in the IP conversion unit 102 in FIG. 2 can also be realized by software by an image signal processing device 300 as shown in FIG. 6, for example.

  First, the image signal processing apparatus 300 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 the image signal V0 to be processed from the input terminal 316, the image signal V0 is recorded in advance in the HDD 305, or downloaded from the communication network 400 such as the Internet via the communication unit 308, and further supplied by the removable disk 306. You may make it do. 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. 7, an IP conversion processing procedure in the image signal processing apparatus 300 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 V0 of the current field and the image signal V2 of the previous field, it is determined whether the interpolated pixel position P existing in the previous field is a motion region or a still region, and the determination result JGM Get.

  Next, in step ST6, based on the image signal V0 of the current field and the image signal of the past predetermined field, a determination result JGU indicating whether or not the interpolation pixel position P is a pixel position located at the upper boundary of the image, And the determination result JGD of whether or not the pixel position is located at the lower boundary of the image is obtained.

  In the determination process of the upper and lower boundaries in step ST6, determination results JGU and JGD are obtained by the processing procedure shown in the flowchart of FIG. That is, the process starts in step ST11, and in step ST12, a determination result RSp indicating whether the interpolation pixel position P is a motion region or a still region is obtained. In this case, the determination results RS1 to RSm at m consecutive time positions t1 to tm are obtained, and the determination result RSp is acquired based on the determination results RS1 to RSm, thereby increasing the accuracy. The determination result RSp indicates a still region when it is determined that all of the determination results RS1 to RSm are still regions, and indicates a motion region otherwise.

  Next, in step ST13, similarly to the processing in step ST12, the interpolation pixel position P indicates whether a predetermined number n of pixel positions existing around the line direction orthogonal to the vertical direction is a motion region or a still region. Determination results RSp1 to RSpn are obtained.

  Next, in step ST14, determination results RSup and RSdp indicating whether adjacent pixel positions Pu and Pd adjacent to the interpolation pixel position P in a predetermined direction (upward and downward) are a motion region or a still region are obtained. In this case, the accuracy is improved by acquiring the determination results based on the determination results RSu1 to RSum and RSd1 to RSdm at the consecutive m time positions t1 to tm. The determination results RSup and RSdp indicate the still region when it is determined that all the determination results RSu1 to RSum and RSd1 to RSdm are still regions, and indicate the motion region otherwise. It is said.

Next, in step ST15, similar to the processing in step ST14, a predetermined number n _U , n _D pixel positions existing in the vicinity of the adjacent pixel positions Pu, Pd in the line direction orthogonal to the vertical direction are moved into the motion region. Determination results RSup1 to RSupn _U and RSdp1 to RSdpn _D indicating whether the region is a still region.

Next, in step ST16, the determination result RSp of the interpolation pixel position P obtained in step ST12, the determination results RSp1 to RSpn of a predetermined number n of pixel positions existing around the interpolation pixel value P obtained in step ST13, based on the determination result RSup1～RSupn _U pixel position of a predetermined number n _U existing around the obtained adjacent pixel position Pu in the determination results of the adjacent pixel position Pu in step ST14 RSup and step ST15, the interpolation pixel A determination result JGU is obtained as to whether or not the position P is a pixel position located at the upper boundary of the image. In this case, when at least one of the determination results RSp and RSp1 to RSpn is a motion region, and all the determination results RSup and RSup1 to RSupn _U are still regions, the interpolation pixel position P is on the image. It is determined that the pixel position is located at the boundary, and otherwise, it is determined that the interpolation pixel position P is not a pixel position located at the upper boundary of the image.

In step ST16, the determination result RSp of the interpolation pixel position P obtained in step ST12, the determination results RSp1 to RSpn of a predetermined number n of pixel positions existing around the interpolation pixel value P obtained in step ST13, based on the determination result RSdp1～RSdpn _D pixel position of a predetermined number n _D existing around the obtained adjacent pixel position Pd in the determination results of the adjacent pixel position Pd at step ST14 RSDP and step ST15, the interpolation pixel A determination result JGU is obtained as to whether or not the position P is a pixel position located at the lower boundary of the image. In this case, when at least one of the determination results RSp and RSp1 to RSpn is a motion region, and all of the determination results RSdp and RSdp1 to RSdpn _D are still regions, the interpolation pixel position P is below the image. It is determined that the pixel position is located at the boundary. Otherwise, it is determined that the interpolation pixel position P is not a pixel position located at the lower boundary of the image.

  After the process of step ST16, the determination process of the upper and lower boundaries is ended in step ST17. Note that the order of the processing of step ST12 to step ST15 may not be the order shown in the flowchart of FIG.

  Returning to FIG. 7, after the process of step ST6, the process proceeds to step ST7. The processing order of steps ST5 and ST6 may be the reverse of the order shown in FIG. In step ST7, based on the determination result JGM obtained in step ST5 and the determination results JGU and JGD obtained in step ST6, pixel data Dip of the interpolation pixel position P is generated.

  In this case, when the determination result JGU indicates that the interpolation pixel position P is not a pixel position positioned at the upper boundary of the image, and the determination result JGD indicates that the interpolation pixel position P is not a pixel position positioned at the lower boundary of the image Generates pixel data Dip of the interpolation pixel position P based on the determination result JGM. That is, when the determination result JGM indicates a motion region, the pixel data Dip is generated using pixel data of at least the upper line or the lower line with respect to the interpolation pixel position P, and when the determination result JGM indicates a still region, Pixel data Dip is generated using pixel data of at least the previous field or the subsequent field with respect to the interpolation pixel position P.

  Further, when the determination result JGU indicates that the interpolation pixel position P is a pixel position located at the upper boundary of the image, pixel data of a predetermined line positioned downward from the line position corresponding to the interpolation pixel position P is used. Thus, when the pixel data Dip of the interpolation pixel position P is generated and the determination result JGD indicates that the interpolation pixel position P is a pixel position located at the lower boundary of the image, the line data corresponding to the interpolation pixel position P is The pixel data Dip at the interpolation pixel position P is generated using pixel data of a predetermined line positioned in the upward direction.

  Next, in step ST8, it is determined whether or not the processing for generating the interpolation data Dip in all the interpolation lines has been completed for the image signal V1 one field before. If the process has not ended, the process returns to step ST5 and proceeds to the process for the next interpolation pixel position. When the process ends in step ST8, the process proceeds to step ST9. In step ST9, 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 V1 and the signal of each corresponding interpolation line are alternately read out from the RAM 303 to obtain the image signal Vp, which is a progressive signal, with the number of lines 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 ST9, 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. 7, it is possible to process the image signal V0 as an interlace signal and obtain an image signal Vp as a progressive signal.

  In the above-described embodiment, it is determined whether or not the interpolated pixel position P of the interlace signal is at the upper or lower boundary of the image, and the pixel at the interpolated pixel position P is determined based on the determination results JGU and JGD. Although data Dip is generated, the image boundary determination device and method according to the present invention can detect the upper and lower boundaries of an image satisfactorily, so that, for example, an effective image range or a letterbox signal is used. It can also be applied to automatic detection of whether or not. In the case of detecting a letterbox signal, if it is detected that there are an upper boundary and a lower boundary at a predetermined position on the screen, it can be determined that the letterbox signal is present.

  Further, in the above-described embodiment, the apparatus for determining whether or not the interpolation pixel position P of the interlace signal is at the upper boundary or the lower boundary of the image has been described. The method determines whether or not any pixel position including a progressive signal is a pixel position located at a predetermined direction of the image, that is, a boundary of an upward direction, a downward direction, a right direction, a left direction, or the like. it can.

  In the above embodiment, the memory 103 is provided outside the IP conversion unit 102. However, the memory 103 may be provided inside the IP conversion unit 102.

  The present invention determines whether the target pixel position is a motion region or a still region, determines whether the adjacent pixel position adjacent to the target pixel position in a predetermined direction is a motion region or a still region, and the target pixel position moves When the target pixel position is a boundary in the predetermined direction of the image, it is determined that the target pixel position is a pixel position positioned at the boundary in the predetermined direction of the image. For example, when converting an interlaced signal to a progressive signal, it is possible to determine whether the interpolated pixel position is a pixel position located at the upper or lower boundary of the image. The pixel data at the interpolated pixel position is generated based on the determination result, and can be applied to a purpose of preventing the occurrence of flicker at the upper boundary and the lower boundary of the main image portion in the letterbox signal.

It is a block diagram which shows the structure of the image display apparatus as embodiment. It is a block diagram which shows the structure of an IP converter. It is a figure for demonstrating the process which determines whether an interpolation pixel position is a motion area | region or a still area | region. It is a figure for demonstrating the determination process of an up-and-down boundary. It is a figure for demonstrating the production | generation process of interpolation pixel data. 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 flowchart which shows the procedure of the determination process of an up-and-down boundary. It is a figure for demonstrating an interlace signal. It is a figure for demonstrating the process of general IP conversion. It is a figure which shows the state by which the image by a letterbox signal was displayed on the screen of a display. It is the figure which expanded and showed the boundary vicinity on the image of a letterbox signal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Image display apparatus, 101 ... Input terminal, 102 ... IP converter, 103, 105 ... Panel driver, 106 ... PDP, 111 ... Write processing part, 112 ... Read processing unit 113... Upper and lower boundary determination unit 114 114 motion / stillness determination unit 115 115 motion adaptive interpolation arithmetic circuit 116 output line selection circuit

Claims (11)

In the image boundary determination apparatus for determining whether the target pixel position is a pixel position located at a boundary in a predetermined direction of the image,
First movement / stillness determination means for determining whether the target pixel position is a motion region or a still region using pixel data at a predetermined time position in a time direction corresponding to the target pixel position;
A second determination is made using pixel data at a predetermined time position in a time direction corresponding to the adjacent pixel position to determine whether the adjacent pixel position adjacent to the target pixel position in the predetermined direction is a moving region or a stationary region. Movement / stillness determination means;
When it is determined that the target pixel position is a motion region by the first movement / stillness determination means, and the adjacent pixel position is a still region by the second movement / stillness determination means, An image boundary determination device comprising: boundary determination means for determining that a target pixel position is a pixel position positioned at a boundary in a predetermined direction of an image. The first movement / stillness determination means uses pixel data corresponding to a plurality of time positions in the time direction, obtains a plurality of determination results at the plurality of time positions, and at least one of the plurality of determination results is The image boundary determination device according to claim 1, wherein when indicating that the region is a motion region, the target pixel position is determined to be a motion region. The second movement / stillness determination means uses pixel data corresponding to a plurality of time positions in the time direction, obtains a plurality of determination results at the plurality of time positions, and all of the plurality of determination results are in a still region. The image boundary determination device according to claim 1, wherein when it indicates that there is an image, the adjacent pixel position is determined to be a still region. A predetermined time in a time direction corresponding to each of the predetermined number of pixel positions, whether the predetermined number of pixel positions existing in the periphery of the target pixel position in a direction orthogonal to the predetermined direction is a moving region or a stationary region. A third movement / stillness determination means for determining using the pixel data of the position;
The boundary determination means determines whether the target pixel position is a movement area by the first movement / stillness determination means or out of the predetermined number of pixel positions by the third movement / stillness determination means. When one of the pixels is determined to be a motion region, and the second motion / stillness determination unit determines that the adjacent pixel position is a still region, the target pixel position is positioned at a boundary in a predetermined direction of the image. The image boundary determination apparatus according to claim 1, wherein the image boundary determination apparatus determines that the pixel position is to be detected. A predetermined time in a time direction corresponding to each of the predetermined number of pixel positions, whether or not the predetermined number of pixel positions existing in the vicinity of the adjacent pixel position in a direction orthogonal to the predetermined direction is a moving region or a stationary region. A fourth movement / stillness determination means for determining using the pixel data of the position;
The boundary determining means determines that the target pixel position is a motion area by the first movement / stillness determination means, and the adjacent pixel position is a still area by the second movement / stillness determination means. And when the fourth motion / stillness determining means determines that the predetermined number of pixel positions are all still regions, the target pixel position is a pixel position located at a boundary in a predetermined direction of the image. The image boundary determination apparatus according to claim 1, wherein: In the image boundary determination method for determining whether the target pixel position is a pixel position located at a boundary in a predetermined direction of the image,
A first movement / stillness determination step for determining whether the target pixel position is a motion region or a still region using pixel data at a predetermined time position in the time direction corresponding to the target pixel position;
A second determination is made using pixel data at a predetermined time position in a time direction corresponding to the adjacent pixel position to determine whether the adjacent pixel position adjacent to the target pixel position in the predetermined direction is a moving region or a stationary region. A movement / stillness determination step;
When it is determined in the first movement / still determination step that the target pixel position is a movement region, and in the second movement / still determination step, the adjacent pixel position is determined to be a stationary region, A boundary determination step of determining that the target pixel position is a pixel position located at a boundary in a predetermined direction of the image. An image signal processing apparatus for converting an interlace signal into a progressive signal,
A boundary determination unit that determines whether the interpolation pixel position is a pixel position located at a boundary in a predetermined direction that is an upward direction or a downward direction orthogonal to the line direction of the image;
A pixel data generation unit that generates pixel data of the interpolation pixel position based on the determination result of the boundary determination unit;
The pixel data generation unit
When the boundary determination unit determines that the interpolation pixel position is a pixel position located at the boundary, pixels on a predetermined line located in a direction opposite to the predetermined direction from the line position corresponding to the interpolation pixel position An image signal processing apparatus characterized by generating pixel data of the interpolation pixel position using data. The pixel data generation unit
The first pixel data of the pixel of the line adjacent to the line corresponding to the interpolation pixel position in the direction opposite to the predetermined direction corresponding to the interpolation pixel position, the previous field corresponding to the interpolation pixel position Of the second pixel data of the pixel and the third pixel data of the pixel of the field after corresponding to the interpolation pixel position, the median pixel data is the pixel data of the interpolation pixel position. Item 8. The image signal processing device according to Item 7. A motion / stillness determination unit that determines whether the interpolation pixel position is a motion region or a still region;
The pixel data generation unit
When the boundary determination unit determines that the interpolation pixel position is not a pixel position located at the boundary, when the motion / still determination unit determines that the interpolation pixel position is a motion region, When the pixel data of the interpolation pixel position is generated using the pixel data of at least the upper line or the lower line, and the interpolation / position determination unit determines that the interpolation pixel position is a still area, The image signal processing apparatus according to claim 7, wherein the pixel data of the interpolation pixel position is generated using pixel data of at least a previous field or a subsequent field. The boundary determination unit
First motion / stillness determination means for determining whether the interpolation pixel position is a motion region or a still region using pixel data at a predetermined time position in the time direction corresponding to the interpolation pixel position;
Determining whether an adjacent pixel position adjacent to the interpolated pixel position in the predetermined direction is a moving region or a stationary region using pixel data at a predetermined time position in a time direction corresponding to the adjacent pixel position; Movement / stillness determination means;
When the interpolated pixel position is determined to be a motion region by the first motion / stillness determination means, and the adjacent pixel position is determined to be a static region by the second motion / stillness determination means, The image signal processing apparatus according to claim 7, further comprising a boundary determination unit that determines that the interpolation pixel position is a pixel position positioned at a boundary in a predetermined direction of the image. An image signal processing method for converting an interlace signal into a progressive signal,
A boundary determination step for determining whether the interpolation pixel position is a pixel position located at a boundary in a predetermined direction that is an upward direction or a downward direction orthogonal to the line direction of the image;
A pixel data generation step for generating pixel data of the interpolation pixel position based on the determination result of the boundary determination step;
In the pixel data generation step,
When it is determined in the boundary determination step that the interpolation pixel position is a pixel position located at the boundary, pixels of a predetermined line positioned in a direction opposite to the predetermined direction from the line position corresponding to the interpolation pixel position An image signal processing method characterized by generating pixel data of the interpolation pixel position using data.

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