JP2006296926A - X-ray imaging apparatus, image processing method, computer readable storage medium and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an X-ray imaging apparatus having a designating means, a position grasping means, and an image processing means of a region of interest image of which is processed using rotation angle information of a subject in the X-ray imaging apparatus capable of acquiring a continuous image using a flat panel. <P>SOLUTION: The X-ray imaging apparatus has a subject rotating means for rotating the subject, a rotating means for the subject, a rotation angle detecting means for the rotating means, a region designating means for designating the region in the image using at least two or more images of the rotation angle, a position calculating means for calculating the three-dimensional position of the regions of interest using two or more regions designated by the region designating means, and a region of interest image processing means for performing image processing to the designated region of interest. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radiation imaging technique for imaging a radiation characteristic distribution in a subject using radiation in general, such as an X-ray moving image capturing apparatus that performs image capturing using radiation such as X-rays. is there.

  A conventional still image capturing apparatus using radiation has a function of performing image processing of a specified portion at the time of display. For example, the “Canon X-ray digital camera CXDI-40G” has a binning display function for enlarging only an area to be viewed.

  The function is suitable when it is desired to view both the entire captured image and a part of the detailed image. A technique for designating a region of interest in the still image and applying image processing such as enlargement processing is known.

  Further, the function can be used even if it is not a function added to the X-ray imaging apparatus. For example, when using viewer software that can operate the image on Windows, which is a Microsoft OS, the above-described enlargement function can be used by using the Windows Mag function.

  On the other hand, various applications are possible with the improvement of moving image characteristics of flat panel X-ray detectors in recent years, and as one of them, by rotating the subject in an arrangement like a standing still image pickup device, A technique capable of imaging CT is being developed (Patent Document 1).

  For example, in a moving image imaging apparatus such as the standing CBCT type X-ray imaging apparatus, as described in Patent Document 2, a predetermined area is set while reducing the resolution and reading rate of an area that does not require high resolution and high speed reading. A high-speed and high-resolution image can be obtained.

  However, there is no three-dimensional designation means for the image processing area using the rotation angle information that can be detected by the rotation mechanism of the subject, and no image processing means for the designation area, and there is no suggestion.

  In Patent Document 3, the projection image is reconstructed into a three-dimensional voxel and then rotated around a specific area. However, there is no known example regarding the function to designate and follow a specific area for the rotated image of the moving image before reconstruction, and there is no suggestion including the possibility of its clinical application. .

JP 2004-337289 A JP 2003-198956 A JP 2001-022964 A

  Accordingly, an object of the present invention is to provide a region-of-interest specifying means for performing image processing, a position grasping means, an image using an object rotation angle information in an X-ray imaging apparatus capable of acquiring continuous images using the flat panel. An object of the present invention is to provide an X-ray moving image pickup apparatus having processing means.

  In order to achieve the above object, an X-ray imaging apparatus of the present invention includes a subject rotation means for rotating a subject, a rotation means for the subject, a rotation angle detection means for the rotation means, and at least two rotation angles. Region specifying means for specifying an area in the image using the image, and position calculating means for calculating a three-dimensional position of the region of interest using the two or more areas specified by the area specifying means. And a region-of-interest image processing means for performing image processing on the designated region of interest.

  The exemplary effects of the present invention are the following two points.

  The first point is that a specific region of interest can be followed in an X-ray rotational moving image. When X-ray moving images are continuously displayed, a specific region can be followed by a human brain circuit, but this has the effect of assisting this.

  The second effect is that it is possible to easily apply the same image processing to the region of interest with respect to images having continuous rotation angles. This is because even a still image that is conventionally diagnosed in front of the chest can be easily displayed at an angle other than the front, so that only the region of interest can be subjected to image processing such as enlargement processing. There is an effect.

  Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

<Embodiment 1>
The present invention is applied to, for example, an X-ray imaging apparatus 1000 as shown in FIG. In particular, the X-ray imaging apparatus 1000 according to the present embodiment fixes and rotates a subject by a subject support mechanism in an X-ray image, acquires X-ray images in continuous frames, performs image processing such as white correction, and the like. It is configured to display a reconstructed image or the like. Next, the configuration and operation of the X-ray imaging apparatus 1000 of this embodiment will be specifically described.

  As shown in FIG. 1, the X-ray imaging apparatus 1000 includes an X-ray generation circuit 1001 that generates X-rays, a two-dimensional X-ray sensor 1005 that detects X-rays 1002 transmitted through a subject 1003, and two-dimensional X-rays. The image capturing unit 1010 that captures image data output from the sensor 1005, a subject support mechanism that supports and fixes the subject 1003, a subject rotation unit 1004, and a rotation angle detection unit 1008, and the obtained rotation angle. Are stored in each image rotation angle: database 1011.

  Instructions for operations for each of them are X-ray imaging execution instructions and various operations for performing various settings on the apparatus 1000 via the operation panel 1012, an X-ray condition setting means 1006, a rotation control means 1007, It is set by the image capturing mode setting means 1009 or the like.

  Main memory 1016 for storing various information such as image data collected by the image capturing means 1010 and processing programs for executing various processes, preview image display setting means 1017 for setting the display image type of the preview image, and setting A preview image display means 1018 for displaying the preview image, an image reconstruction means 1019 for creating a CT reconstruction image using a plurality of images, a diagnostic image processing means 1020 for performing various diagnostic image processing, and a diagnosis Diagnostic image display means 1021 for displaying an image that has undergone various types of image processing, a region of interest designation means 1022 for designating a specific region of interest, and a region of interest calculation for computing the three-dimensional position of the region of interest Means 1023; region of interest display means 1024 for displaying the calculated region of interest; and the calculated region of interest. A region-of-interest image processing unit 1025 that performs only image processing, and a CPU 1008 that controls the overall operation of the apparatus 1000, and includes an image capturing unit 1010, a preview image display setting unit 1017, a preview image display unit 1018, and a region of interest designation. Means 1022, region-of-interest calculation means 1023, region-of-interest display means 1024, region-of-interest image processing means 1025, CPU 1015, main memory 1016, and operation panel 1012 are connected to each other via a CPU bus 1014 so that they can communicate with each other. .

  FIG. 2 is a flowchart showing the operation of the X-ray imaging apparatus 1000.

  In performing the operation according to the flowchart of FIG. 2, for example, the main memory 1009 stores data and processing programs necessary for executing various processes in the CPU 1008 and is used as a work memory (work memory) for the CPU 1008. However, in particular, the processing program according to the flowchart of FIG. 2 is stored as a processing program for image processing according to the present embodiment. Accordingly, the CPU 1015 reads out and executes an image processing program (a processing program according to the flowchart of FIG. 2) from the main memory 1016, thereby performing an X-ray as described below according to an operation from the operation panel 1012. Control for the operation of the photographing apparatus 1000 is performed.

  Step S201: The X-ray imaging apparatus 1000 rotates the subject rotating unit 1004 and rotates the subject 1003 on it while being controlled by the rotation control unit 1007. In synchronization with the rotation of the subject rotation means, the X-ray generation circuit 1001 generates X-rays under the conditions set by the X-ray condition setting means 1006.

  The two-dimensional X-ray detection unit 1005 detects a continuous X-ray image in which the subject is rotated, and acquires an image with the image capture unit 1010 under the conditions set by the image capture mode setting unit 1009. The rotation image of each subject stores the angle information obtained by the rotation angle detection means 1008 in each image rotation angle: database 1011.

  Thus, a standing CBCT image is taken. While the object support mechanism is rotating, the rotation angle detection means 1008 such as an encoder creates each rotation angle at the time of photographing each image as a database (step S201).

  Step S202: The continuous image obtained in the previous step needs to display a confirmation image in a short time in order to determine whether or not re-shooting is necessary. The confirmation items are whether or not the irradiation area is appropriate, whether or not the subject is moving greatly during imaging, whether or not a sufficient dose for diagnosis or the like is obtained. In confirming the confirmation item, if all the images obtained in the previous step are transferred, the transfer time becomes a bottleneck, and it may take a relatively long time to display.

  Therefore, “temporal thinning” in which not all images obtained in the previous step are transferred, but temporally and spatially thinned images are transferred will be described. If the image obtained in the previous step is, for example, 200 fps (Frame Per Second) and a total of 1000 images, for example, 1 out of 10 images, that is, a total of 100 images of 20 fps is thinned out. Refers to transfer.

  Next, spatial thinning will be described.

  Spatial thinning indicates that, for example, if the image has a pixel pitch of 160 μm, transfer is performed by thinning out only one pixel within a pixel pitch of 16 pixels, that is, 6400 μm (step). S202).

  Step S203: The continuous image transferred in the previous step S202 is stored in the main memory 1016. In step S203, the preview image display setting unit 1017 sets the continuous image display method. As display method selection candidates, (•) still image display, (•) moving image display, and (•) reconstructed image display can be selected. Of course, any of the selected branches is set as a default before shooting in step S201, and even if it is not selected in step S203 after shooting, it is displayed in the default display method. (Step S203).

  Step S204: When (.) Still image display is set by the previous step S203 or setting means of the same function, one of the images transferred in the step S202 is displayed. The displayed still image may be set before step S201. The image at a specific rotation angle is previewed as a still image based on each image rotation angle: database 1011. The setting displayed on the image display means 1018 may be used (step S203).

  Step S205: This is a selection step most relevant to the present invention when (.) Moving image display is selected in Step S203. The image thinned and transferred in step S202 is displayed as a moving image on the preview image display means 1018 (step S205).

  Step S206: The region of interest designating unit 1022 designates the region of interest when it is desired to follow a specific region of the image on which the moving image is displayed in the previous step, or to perform image processing such as enlargement on the specific region. A specific region of interest designation method and the like will be described later with reference to other drawings. The region of interest specified in this step is calculated by the region of interest calculation means 1023 (step S206).

  Step S207: The region of interest image processing unit 1025 performs image processing on the portion of the region of interest designated and calculated in the previous step. Examples of the image processing to be performed include enlargement processing, sharpening processing, noise reduction processing, and multi-frequency processing. Image processing that can be performed in a relatively short time is preferably the image processing (step S207). .

  Step S208: The entire image displayed as a moving image in Step S205 and the region of interest subjected to the image processing in Steps S206 to S207 are simultaneously displayed on the preview image display means 1018. The reason for the simultaneous display is that if only the region of interest is displayed, the entire position is difficult to understand subjectively (step S208).

  Step S209: When (.) Reconstructed image display is selected in step S203, a preview reconstructed image is calculated. Compared to other options in step S203, the display takes time. Therefore, the purpose of displaying the reconstructed image in the preview image is to (a) check whether there is any noise or body movement peculiar to reconstruction that cannot be understood by other options, and (b) later in step S213. This is a guideline for determining a slice position, an image size, a slice thickness, the number of slices, and the like when displaying a reconstructed image for diagnosis (step S209).

  Step S210: The preview reconstructed image calculated in the previous step S209 is displayed. It is desirable that the displayed image can simultaneously display a reconstructed image of a certain cross section and a reconstructed image in the vertical direction in accordance with the purpose described in step S209 (step S210). .

  Step S211: In the previous step S202, since the thinned image was transferred as described above in order to transfer in a short time, this step S211 is performed after the transfer is completed. Of course, this is performed in parallel with steps S203 to S210. All image transfer without thinning takes a relatively long time due to the transfer cable, the writing speed to the memory, the writing speed to the hard disk, etc. (step S211).

  Step S212: When all the images are transferred in the previous step S211, the image reconstruction means 1019 calculates a reconstructed image. The calculation of the reconstructed image from the projection image may be performed by a commonly used method such as Feldcamp, or a further accelerated algorithm may be used (step S212).

  Step S213: The reconstructed image calculated in the previous step S212 is displayed on the diagnostic image display means 1021.

  Step S214: A diagnosis is performed based on the image obtained in the previous step S213. Although not shown, when a slice cross section necessary for diagnosis is not obtained, the process returns to Step S212 or Step S201 for calculating the reconstructed image, and the reconstructed image is calculated again, or the alignment is read again. It may be determined that it is necessary to take a picture (step S214).

  FIG. 3 is a diagram showing an example of simultaneous display of a moving image and an image of a designated area when the present invention is implemented. FIG. 4A is an image of the front of the chest. In particular, the area to be enlarged is specified. FIG. 4B shows an enlarged image of the area. FIG. 4A is a standing rotation image. Therefore, the chest in the image is displayed while being rotated. In particular, the area specified in the present invention can be followed even during the moving image display. That is, the region of interest continues to be designated while being fixed to the same region of the chest.

  FIG. 4 is a diagram showing an operation screen and a display screen when the present invention is implemented. On the display screen 401, a (.) Moving image chest rotation image and a (.) Enlarged image are displayed simultaneously. A setting screen for various image processing is provided as a window 402 on the display screen 401, and various adjustment settings can be made.

  FIG. 5 shows an enlarged display setting screen according to the present invention. (A) is a photographed image (enlarged image) confirmation screen, and (b) is an enlarged display setting screen. In addition, it is desirable that not only the enlargement ratio and the like can be set on the enlargement display setting screen of (b), but also an enlargement target and a setting such as enlargement display can be made.

  FIG. 11 is a diagram illustrating a region of interest designating unit and a region of interest calculating unit according to the present invention. FIG. 3 is a flowchart illustrating a part of the flowchart of the operation of the X-ray imaging apparatus 1000 in FIG.

  Step S1101: First, a projection image is taken. This operation is exactly the same as step S201 in FIG. 2 (step S1101).

  Step S1102: Next, a moving image is displayed as a projection image. This operation is the same state as when (.) Moving image display is selected by default in step S203 of FIG. 2 (step S1102).

  Next, a method for designating a region of interest corresponding to step S206 in FIG. 2 will be described using steps S1103 to S1106.

  Step S1103: First, the rotation image displayed as a moving image in Step S1102 is stopped at the first rotation angle and displayed as a still image for specifying the region of interest (Step S1103).

  Step S1104: Next, a region of interest is designated in the still image at the first rotation angle. Specifically, in the displayed still image, (1) the region of interest is designated by a touch panel, (2) the region of interest is designated by using an operation means such as a mouse (step S1104).

  Step S1105: Next, the moving image display is stopped at a rotation angle different from that in step S1103, and the still image display is performed. At this time, it is desirable that the angle is as far as possible from the angle specified in step S1103. Similarly, it is desirable that the difference between the rotation angle and step S1103 is not close to 180 °. This is because it is clear in principle that the error of the calculated position becomes large (step S1105).

  Step S1106: Next, in Step S1106, the region of interest is specified in the still image at the second rotation angle (Step S1106).

  Step S1107: A region of interest is determined based on the region of interest designated in the two steps S1104 and S1106. A specific method of determining a region of interest will be described later with reference to FIG. 12 (step S1107).

  Step S1108: The position of the region of interest obtained in the previous step S1107 is made to correspond to the position in the image obtained by continuously rotating and displaying each projection image (step S1108).

  Step S1109: Image processing of the region of interest corresponding to the position on each rotated moving image is performed in the previous step S1108. This step S1109 is the same processing process as step S206 of FIG. Examples of the image processing include enlargement processing, sharpening processing, noise reduction processing, multi-frequency processing, and the like (step S1109).

  Step S1110: The projection image obtained by performing image processing only on the region of interest in the previous step S1109 and the projection image displayed in step S1102 are simultaneously displayed (step S1110).

  FIG. 12 is a diagram for explaining a region of interest designating unit and a region of interest calculating unit in the present invention.

  The entire process flow is composed of three steps.

  (1) Specify a region of interest in still images at two rotation angles.

  This is the same as the sum of step S1104 and step S1106 in FIG.

  First, a region of interest is designated at the first rotation angle. At this time, simply specifying one image only indicates that the region of interest is on a certain straight line.

  Next, the region of interest is specified at the second rotation angle. By designating the region of interest at an angle different from the angle 1, it is understood that the region of interest is on another straight line.

  (2) A method of calculating a region of interest.

  Since it has been found in (1) that the region of interest exists on two straight lines, the intersection of the two straight lines becomes the region of interest.

  (3) A method of calculating a region of interest from two straight lines (when there is no intersection).

  Considering two-dimensionally, two straight lines always have an intersection unless they are parallel straight lines. However, in three dimensions, both straight lines may not have an intersection. That is, both straight lines are not on the same plane.

  (3-1) Find the shortest distance between two straight lines and find the point connecting the shortest distances.

  (3-2) The midpoint of the two points indicating the obtained shortest distance is obtained as the midpoint of the region of interest.

  As described above, even when the two straight lines do not intersect, it is possible to calculate the point closest to the intersection.

  FIG. 6 is a configuration diagram of a conventional X-ray CT. For comparison with the configuration of this embodiment, it is included for reference. In the configuration of the conventional example, it is understood that a function capable of grasping the position of each region of interest by detecting the rotation angle as in the present invention is impossible.

  FIG. 7 is an explanatory diagram of a standing CBCT type X-ray imaging apparatus in the present embodiment.

  The region of interest in the rotated image is designated by the method described with reference to FIGS. FIG. 7 shows an example of a configuration diagram necessary for specifying the region of interest. An encoder which is a means for detecting a rotation angle is attached to a rotation shaft for rotating the subject. Using this encoder, each rotation angle is stored in each image rotation angle: database. Therefore, rotation angle information of each image necessary for the region of interest calculation means of the method of FIGS. 11 and 12 is obtained.

In this embodiment, the region of interest is described as an intersection. However, the scope claimed in the present invention is not limited to the intersection. For example, in the first embodiment, the region of interest may be specified as a rectangular parallelepiped having a specified size. Furthermore, it is needless to say that the three-dimensional shape of the region of interest is not limited to a shape such as a rectangular parallelepiped, and may be spherical.
<Embodiment 2>
FIG. 8 is a diagram for explaining the second embodiment of the present invention. The first embodiment is a standing CBCT X-ray imaging apparatus. The first embodiment is an example in a standing CBCT type X-ray imaging apparatus. In the present embodiment, the present invention is applied to a supine X-ray CT imaging apparatus.

  FIG. 8 is a greatly enlarged view of the number of detected pixels of conventional X-ray CT, such as 4 and 16 columns. As the X-ray detector, the FPD type X-ray detector as in the first embodiment is used. Advantages of the imaging apparatus using such a large FPD X-ray detector include that imaging time is shortened and that body movement is expected to be reduced.

  If the three relative relationships among the subject, the X-ray detector, and the X-ray generator in FIG. 8 are clear, the projection image is used as the preview image at the two subject rotation angles as in the first embodiment. The region of interest can be specified. Therefore, when displaying a projected image of a moving image, it is possible to display the moving image while performing image processing only on the region of interest using the angle information of the rotating device.

  It is to be noted that an object of the present invention is to supply a storage medium storing software program codes for realizing the functions of the apparatus according to the first and second embodiments to a system or apparatus, and the system or apparatus computer (or CPU) Needless to say, this can also be achieved by reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the first and second embodiments, and the storage medium storing the program code and the program code constitute the present invention. As a storage medium for supplying the program code, ROM, flexible disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, and the like can be used.

  Further, by executing the program code read out by the computer, not only the functions of the first and second embodiments are realized, but the OS running on the computer based on the instruction of the program code is actually It goes without saying that the case where the functions of the first and second embodiments are realized by performing part or all of the processing and the processing is included in the embodiment of the present invention.

  Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the case where the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the first and second embodiments are realized by the processing is also included in the embodiment of the present invention. Yes.

  The embodiment of the present invention is not limited to the first and second embodiments. For example, in a normal recumbent X-ray imaging apparatus, an X-ray imaging apparatus in which the cylindrical side faces are all FPD detectors may be used. In this case, the range in which the X-ray tube can rotate may be a space where the X-ray tube can be moved in the FPD detector spreading over the entire surface of the cylinder. You may make it the structure which can be made small and can be moved. FIG. 9 shows one such embodiment, and is referred to as embodiment 3.

  As mentioned above, although preferable embodiment of this invention was described, it cannot be overemphasized that this invention is not limited to these embodiment, A various deformation | transformation and change are possible within the range of the summary.

  Also, an object of the present invention is to supply a storage medium (or recording medium) in which a program code of software that realizes the functions of the above-described embodiments is recorded to a system or apparatus, and the computer of the system or apparatus (or Needless to say, this can also be achieved by the CPU and MPU) reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention.

  Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an operating system (OS) or the like running on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.

  Furthermore, as shown in FIG. 13, the X-ray imaging apparatus according to the present invention can be inserted into a universal arm, C arm, cassette holder or the like as a gantry and used in the same configuration.

It is a figure which shows the function structure of this invention. It is a figure which shows the flowchart of operation | movement of the X-ray imaging apparatus of this invention. It is a figure which shows display correspondence of the moving image and the region of interest image at the time of implementation of this invention. It is a figure which shows the operation screen at the time of implementation of this invention, and a display screen. It is a figure which shows the setting screen of the enlarged display of this invention. It is a figure which shows the flowchart (time series) of this invention. It is a figure which shows the flowchart of this invention. It is a figure which shows a prior art example. It is a figure which shows Embodiment 1 in this invention (standing position CBT). It is a figure which shows Embodiment 2 in this invention (CT). It is a figure which shows Embodiment 3 in this invention (CT). It is a figure explaining the region-of-interest specifying means and the region-of-interest calculating means in the present invention. It is the figure which showed the example of the various imaging system which can attach and install the X-ray imaging device in this invention.

Explanation of symbols

1000 X-ray imaging system 1001 X-ray generation circuit 1002 X-ray beam
1003 Subject 1004 Subject rotation means 1005 Two-dimensional X-ray detection means 1006 X-ray condition setting means 1007 Rotation control means 1008 Rotation angle detection means 1009 Image capture mode setting means 1010 Image capture means 1011 Each image_rotation angle: database 1012 operation means 1013 System control means 1014 CPU bus 1015 CPU
1016 Main memory 1017 Preview image display setting means 1018 Preview image display means 1019 Image reconstruction means 1020 Image processing means 1021 Diagnosis image display means 1022 Region of interest designating means 1023 Region of interest calculation means 1024 Region of interest image processing means

Claims (11)

In an X-ray imaging apparatus that obtains a moving image by irradiating X-rays while rotating a subject,
The subject rotation means, the rotation angle detection means of the rotation means, the area designation means for designating an area in the image using the image having at least two or more rotation angles, and the area designation means A position calculating unit that calculates a three-dimensional position of the region of interest using two or more of the specified regions; and a region of interest image processing unit that performs image processing on the specified region of interest. X-ray imaging apparatus.   The X-ray imaging apparatus according to claim 1, further comprising a display unit that displays an image of the region of interest image-processed by the region-of-interest image processing unit simultaneously with the moving image.   The X-ray imaging apparatus according to claim 1, wherein the image processing unit includes an image enlargement processing unit.   The X-ray imaging apparatus according to claim 1, wherein the X-ray image capturing apparatus rotates a subject to capture a moving image, and reconstructs X-ray transmission characteristics of each cross section based on the obtained plurality of images. Image shooting device.   The display means includes display means for displaying a still image, display means for displaying a continuous moving image, and means for selecting a display means for displaying a three-dimensional reconstructed image. The X-ray imaging apparatus according to claim 1, wherein:   2. The X-ray imaging apparatus according to claim 1, wherein the rotation angle detecting means is an encoder. An image processing method for outputting an image of an X-ray imaging apparatus provided with a two-dimensional planar radiation detection unit that irradiates an X-ray while rotating a subject and acquires a moving image,
A step of rotating the subject, a step of detecting a rotation angle of the rotation means, an area specifying step of specifying an area in an image using at least two images of the rotation angle, and the area specifying means A position calculating step of calculating a three-dimensional position of the region of interest using the two or more specified regions, and a region of interest image processing step of performing image processing on the region of interest. An image processing method.   A computer-readable storage medium storing a program for causing a computer to realize the function of the image processing apparatus according to any one of claims 1 to 6 or the function of the image processing system according to claim 6.   A computer-readable storage medium storing a program for causing a computer to execute the processing steps of the image processing method according to claim 7.   The program for making a computer implement | achieve the function of the image processing apparatus in any one of Claims 1-6, or the function of the image processing system of Claim 6.   A program for causing a computer to execute the processing steps of the image processing method according to claim 7.

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