JP2004233198A - Method and apparatus for determination of corresponding point with measurement point in photogrammetry - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly, precisely perform determination of a corresponding point by reducing correlation processing burdens in the mapping of a measurement point in photogrammetry. <P>SOLUTION: A relation expression of a nearly plane surface 20 or a virtual plane 120x approximating to the nearly plane surface 20 is derived by specifying reference points 22-29 on nearly plane surfaces 20, 120 that can be approximated as a nearly plane surface, where a measurement point 21 exists. Intersections 21, 21x of rays L1, L2, which pass through the plane 20 or the virtual plane 120x and the measurement point 21 on a reference image 110 and an optical axis center 100a of a reference camera, are obtained. The intersection 21 is projected onto an inspection image 210 for determining the point as a mapping point 21b. Alternatively, a setting region 41 is set with the intersection 21x as the center, a division region 41b, where the setting region 41 is projected to the inspection image, is subjected to pattern matching, and the mapping point is determined. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention is intended to associate measurement points in photo analysis performed using two or more stereo images, and in particular, in three-dimensional stereo measurement by computer analysis performed using digital photo images, The present invention relates to a system for performing association.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a technique of analyzing a stereo image, in particular, a technique of computer-analyzing a subject captured in the image using a digital image has been used in the field of photogrammetry, and is particularly used for creating a topographic map. .
[0003]
For the computer analysis of this stereo image, it is necessary to derive the positional relationship between at least two cameras and to associate the measurement points respectively projected on the photographic images taken by the two cameras. Specifically, a measurement point projected on one photographic image is specified in another photographic image, and measurement is performed using two-dimensional coordinates on the two plural photographic images and three-dimensional coordinates of the camera. Derive the three-dimensional coordinates of the point.
[0004]
Since it is difficult to accurately associate the same measurement point in a plurality of photographs with a manual operation by visual observation, Japanese Patent No. 3316682 (Patent Document 1) discloses a method such as pattern matching using a computer. A technique performed by a correlation process is disclosed.
[0005]
However, in the correlation processing for performing the association, performing the processing on all the regions of the photographic image increases the processing time, and, for example, the erroneous association is performed on a photographic image including a similar pattern repeatedly. There is also a problem that it is carried out in a different position. In order to solve this problem, various techniques for narrowing the area for performing the correlation process and solving the above problem have been proposed.
[0006]
In Japanese Patent Application Laid-Open No. 2001-28095 (Patent Document 2), a search area is set based on at least three segmentation points, and a correlation process is performed on images of the search areas to perform a correlation process. Is disclosed.
[0007]
Also, in a paper by Mosquito et al. (Non-Patent Document 1) and a publication by Xu Go (Non-Patent Document 2), the correlation processing is performed by narrowing the region to be subjected to the correlation processing on the epipolar line using the epipolar constraint. A technique for reducing the search area to be performed is disclosed (Non-Patent Document 1, page 528, left column, lines 9 to 14, Non-Patent Document 2, pages 31 to 32).
[0008]
However, FIG. As shown in FIG. 1, an epipolar line in which a half-line (light ray to the measurement point) passing through the measurement point starting from the center of the optical axis is projected on another photographic image usually extends from one end of the other photographic image to the other end. Will be there. Therefore, even in this technique, the area for performing the correlation processing is extensive. Therefore, if this can be further narrowed down, the correlation processing can be performed at higher speed and with higher accuracy. On the other hand, if the measurement point on another image deviates from the search area due to excessively narrowing the area, photogrammetry itself can no longer be performed.
[0009]
[Patent Document 1]
Japanese Patent No. 3316682 [Patent Document 2]
Japanese Patent Application Laid-Open No. 2001-280955 [Non-Patent Document 1]
Hiroshi Kamosano, 3 others, "Realization of Camera Geometric Correction Function in Video Rate Stereo Machine", Journal of the Robotics Society of Japan, May 1998, Vol. 16, No. 4, p. 527-532.
[Non-patent document 2]
Xu Go, "3D CG from Photographs", Modern Science Company, January 2001, p. 31-33
[0010]
[Problems to be solved by the invention]
Therefore, a technical problem to be solved by the present invention is to reduce the burden of the correlation processing and to perform the association at higher speed and with higher accuracy in associating the measurement points in photogrammetry.
[0011]
[Means for Solving the Problems]
The present invention provides the following method of associating measurement points in photogrammetry in order to solve the above technical problem.
[0012]
This method creates a reference image and an inspection image respectively taken by a reference camera whose positional relationship is known and an inspection camera arranged at a different position from the reference camera, and arranges them on a substantially plane on the reference image. Specify a plurality of reference points, calculate the relational expression of the substantially plane based on the position of the reference point, a straight line passing through the optical axis center of the reference camera and the measurement point specified in the reference image The three-dimensional coordinates of an intersection that intersects the substantially plane are calculated, and a corresponding point of a measurement point on the inspection image is determined based on the intersection.
[0013]
In the above method, the positional relationship between the reference camera and the inspection camera, that is, the coordinate value indicating where the other camera (inspection camera) is located and the direction in which the other camera is directed, when viewed from the coordinate system of the reference camera. The angle indicating whether or not it is known is known. Therefore, if it is possible to specify an arbitrary point in both the reference image and the inspection image in association with each other, the three-dimensional coordinates of the point can be specified.
[0014]
Generally, in a three-dimensional space, a plane including at least any three points can be defined as one, and a relational expression of the plane can be derived. By designating a reference point on a substantially plane that can be approximated as a substantially plane, a relational expression of a plane including the reference point is derived. If the relational expression of the approximate plane becomes clear, the three-dimensional coordinates of an arbitrary point on the plane can be derived. That is, a measurement point can be specified in a substantially plane on the reference image, and three-dimensional coordinates can be derived from an intersection point where a straight line connecting the optical axis center of the reference camera and the measurement point on the substantially plane intersects the plane. In addition, it is possible to guide to which position on the inspection image the intersection where the three-dimensional coordinates are known is projected. The corresponding point can be determined based on the intersection existing on the inspection image.
[0015]
According to the above method, by designating a reference point on a substantially plane where a measurement point exists, a relational expression of the substantially plane is derived, and inspection is performed from three-dimensional coordinates of the measurement point calculated in relation to the substantially plane. Since the corresponding points of the measurement points projected on the image can be determined, it is possible to reduce the burden of the correlation processing performed on the inspection image by a technique such as pattern matching as in the related art. Therefore, in associating the measurement points in the photogrammetry, it is possible to reduce the load of the correlation processing and perform the association with higher speed and higher accuracy.
[0016]
This method can be implemented in various modes as described below.
[0017]
Preferably, a corresponding point of the measurement point on the inspection image is the intersection.
[0018]
In the above method, for example, when the plane on which the reference point and the measurement point are located is a perfect plane, a straight line passing through the optical axis center of the reference camera and the measurement point specified in the reference image (for the measurement point) A point where an intersection point where the light ray intersects with the substantially plane is projected on the inspection image can be used as a corresponding point as it is. According to the above method, the corresponding point of the measurement point can be determined by extremely simple processing.
[0019]
Preferably, the corresponding point of the measurement point on the inspection image is determined by performing a correlation process on the measurement point on the reference image and a predetermined area near the point where the intersection point is projected on the inspection image. Is done. In this case, it is preferable that the size of the predetermined area can be changed.
[0020]
In the above method, for example, a plane where a reference point and a measurement point are present is a slightly curved surface such as a road, but can be approximated as a substantially flat surface, or a calculation or operation error. In such a case, the intersection may not indicate an exact corresponding point. However, since the intersection exists near the accurate corresponding point within the range of the above error, the correlation processing is performed on an area of a predetermined size in the vicinity of the intersection to obtain the accurate corresponding point. Can be determined. It is preferable that the size of the predetermined region can be changed according to, for example, the curvature of an approximate plane.
[0021]
Therefore, according to the above configuration, in associating the measurement points in the photogrammetry, the area for performing the correlation processing can be reduced, and the association can be performed with higher speed and higher accuracy.
[0022]
Further, the present invention provides a reference point designating means for receiving an input of a plurality of reference points present on a substantially plane on a reference image and an inspection image photographed from different positions having a known mutual positional relationship, and Plane calculating means for calculating the relational expression of the substantially plane based on the coordinate values of the reference point on the reference image and the inspection image, and measurement point designating means for designating a measurement point within the substantially plane on the reference image An intersection calculating means for calculating an intersection at which a straight line passing through the optical axis center of the reference camera and the measurement point intersects the substantially plane; and determining a corresponding point of the measurement point on the inspection image based on the intersection. And a corresponding point determination unit for performing photogrammetry.
[0023]
Further, the present invention provides a computer for associating measurement points in photogrammetry with a plurality of reference images existing on a substantially plane on a reference image and an inspection image taken from different positions whose positional relationship is known. A reference point designating unit that receives a point input; a plane calculating unit that calculates a relational expression of the substantially plane based on coordinate values of the input reference point on the reference image and the inspection image; A measuring point designating means for designating a measuring point in a plane, an intersection calculating means for calculating an intersection at which a straight line passing through the optical axis center of the reference camera and the measuring point intersects the substantially plane, and Provided is a program for associating measurement points in photogrammetry to function as corresponding point determination means for determining corresponding points of measurement points on an inspection image.
[0024]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a photogrammetry system according to an embodiment of the present invention will be described with reference to the drawings.
[0025]
This apparatus is configured by a computer for inputting a photographic image and performing an analysis operation. The photographic image is preferably an image taken by a digital camera, but may be an image obtained by converting a photograph taken by a film camera into data using a scanner or the like. The camera may be a camera for photo measurement with an internal orientation, or may be a general-purpose digital camera without an internal orientation. A general-purpose computer can be used, and the computer is driven by installing a program that causes the computer to perform a process described below using a storage medium storing the program.
[0026]
FIG. 1 shows a block diagram of a photogrammetry apparatus according to an embodiment of the present invention. The photogrammetric apparatus 1 is used by connecting to external devices such as a camera 11, an input device 12 such as a keyboard and a mouse, and a display 13. The device 1 includes an interface device 10 for connecting to the external device, a system program storage unit 3, an image storage unit 4, a position specification unit 5, a coordinate calculation unit 6, a plane calculation unit 7, a correlation processing unit 8, a calculation unit The unit 9 is mounted and interconnected by the bus 2.
[0027]
The system program storage unit 3 stores a system program when the above software is installed. The image storage unit 4 stores a photographic image captured from the camera 11. The photographic image is read from the image storage unit 4 and displayed on the display 13 when the photogrammetry is executed.
[0028]
As will be described later, the position designation unit 5, the coordinate calculation unit 6, the plane calculation unit 7, and the correlation processing unit 8 perform specific processes and calculations when performing photogrammetry by driving a system program. The calculation unit 9 performs processing other than the processing performed by the position designation unit 5, the coordinate calculation unit 6, the plane calculation unit 7, and the correlation processing unit 8.
[0029]
(1st Embodiment)
FIG. 2 is a flowchart showing the flow of processing according to the first embodiment when performing photogrammetry using the photogrammetry apparatus of FIG. The first embodiment is preferably used when the plane on which the measurement points exist is a perfect plane.
[0030]
First, a stereo image is taken and transmitted to the photogrammetry device 1 and stored in the image storage unit 5 to create a basic image and an inspection image (# 10). The basic image and the inspection image are two or more photographic images obtained by photographing the same subject from different positions using the digital camera 7. Hereinafter, in the present embodiment, a case where two photographic images are used will be described. One photographic image is distinguished as a reference image and the other one is an inspection image. Which one of the two photographic images is used as the reference image is optional, and any one can be selected.
[0031]
FIG. 3 is a diagram illustrating a coordinate system when performing photogrammetry. The two photographic images 110 and 210 taken from the two cameras A and B have origins at the respective optical axis centers 100a and 200a, the optical axis direction of the camera is the Z axis, and the longitudinal direction of the photographic image is The X axis and the shorter direction are the Y axis. Therefore, the X axis is not always parallel to the ground surface E according to the tilt of the camera. In the present embodiment, three-dimensional coordinates are specified based on the camera that captured the reference image. That is, when the photographic image 110 captured by the camera A is used as the reference image, the X1, Y1, and Z1 axes are used as the reference coordinate system. Hereinafter, a case will be described in which camera A is used as a reference camera and a photographic image taken by camera A is used as a reference image.
[0032]
FIG. 4 shows an example of a photographic image used for photogrammetry. FIG. 4A shows a photographic image (reference image) photographed by the camera A, and FIG. 4B shows a photographic image (inspection image) photographed by the camera B. FIG. 4 shows an image in which the specification of the reference points 22a to 30a, 22b to 30b and the measurement point 21a, which is a step to be described later, has already been completed for the sake of understanding. It is needless to say that the specified reference points 22a to 30a, 22b to 30b and the measurement point 21a are not displayed in the image transmitted from the camera 11 and not yet processed.
[0033]
Next, a plurality of reference points 22a to 30a and 22b to 30b are designated for these reference image 110 and inspection image 210 (# 11). From the appearance of the subject, a position such as a corner that is easy to determine is selected, and the same point is designated in both images while referring to the two photographic images 110 and 210. This input is performed by the user operating the input device 8 such as a mouse, and the position specifying unit 5 of the device 1 manages main processing. It is preferable to input at least five or more reference points, and it is preferable to associate at least three or more points 22a to 29a and 22b to 29b existing on a plane 20 that can be approximated to a plane such as a road. . FIG. 5 is a distribution diagram in which only the reference points attached to the reference image 110 and the inspection image 210 are extracted.
[0034]
Next, based on the coordinate values of the reference point designated in the previous step on the reference image and the inspection image, the coordinate calculation unit 6 calculates the positional relationship between the cameras A100 and B200 (# 12). In the present embodiment, as the positional relationship, a coordinate value indicating where the optical axis center of the camera B200 (inspection camera) is located and the camera B200 in the reference coordinate system whose origin is the optical axis center of the camera A100 (reference camera). An angle indicating the direction in which the optical axis is directed. Subsequently, the coordinate calculation unit 6 obtains three-dimensional coordinates of the reference points 22 to 30 based on the obtained positional relationship between the camera A100 and the camera B200 (# 13).
[0035]
Next, as shown in FIG. 6, the plane calculation unit 7 uses the coordinates of the reference points 22 to 29 existing on the same plane 20 among the three-dimensional coordinates of the reference points obtained in the previous step, and A relational expression of the plane is obtained (# 14). At this time, the relational expression of the plane is defined as one by using the coordinates of at least three reference points.
[0036]
Next, as shown in FIG. 7, the position designation unit 5 designates a point (measurement point projection point) 21a where the measurement point appears on the reference image by operating the input device 12 (# 15). FIG. 8 is a view of FIG. 7 as viewed from the direction of arrow 51. The measurement point 21 exists on the same plane as the reference points 22 to 29 as described above. Therefore, a straight line L1 (light ray for the measurement point) connecting the optical axis center 100a and the measurement point (measurement point projection point) 21a on the reference image 110 is created, and the intersection of the light ray L1 and the plane 20 is determined (# 16). ). Since it is clear that the measurement point 21 exists somewhere on the light ray L1 and that the measurement point 21 exists on the plane 20, the three-dimensional coordinates of the intersection of the light ray L1 and the plane 20 remain unchanged. It indicates the three-dimensional coordinates of the measurement point 21.
[0037]
In this way, the three-dimensional coordinates of the measurement point 21 can be derived, but the three-dimensional coordinates of the measurement point can be confirmed using the inspection image. As shown in FIG. 9, the intersection determined in the above steps is projected on the inspection image 210. That is, a line M1 connecting the three-dimensional coordinates of the intersection obtained in the above step and the optical axis center 200a of the inspection camera B200 is a point 21b passing on the inspection image 210, and a corresponding point of a measurement point on the inspection image 210. It becomes. Using the coordinate values on the image of the corresponding point 21b on the inspection image 200 and the measurement point 21a (measurement point projection point) specified on the reference image, it is possible to confirmably obtain the three-dimensional coordinates of the measurement point 21. it can.
[0038]
According to this embodiment, when the surface 20 on which the measurement point 21 exists is a perfect plane, the three-dimensional coordinates of the measurement point can be obtained without obtaining the corresponding point on the inspection image, and photogrammetry can be easily performed. And the processing load can be reduced. In addition, the corresponding points on the inspection image can be determined without performing correlation processing by pattern matching or the like. For example, errors in the association of the reference points 22 to 29 or the calculation of the relational expression of the plane can be determined. Can be substantially reduced.
[0039]
(2nd Embodiment)
FIG. 10 is a flowchart illustrating a flow of a process according to the second embodiment when performing photogrammetry using the photogrammetry apparatus of FIG. 1. The second embodiment is suitably used when the surface on which the measurement points are present can be approximated to be substantially flat, such as a road surface.
[0040]
In the processing flow of the second embodiment, the steps from # 20 to # 23 are almost the same as the steps from # 10 to # 13 of the first embodiment. When the three-dimensional coordinates of the reference points 22 to 30 are determined by these steps, as shown in FIG. 12, of these reference points, only the reference points 22 to 29 existing on the substantially plane 120 are selected and From the three-dimensional coordinates, a virtual plane 120x, which is a complete plane to which these reference points 22 to 29 come closest, is assumed, and the relational expression is derived (# 24). In other words, although the shape of the true approximate plane 120 where the reference points 22 to 29 actually exist is unknown, the relational expression of the virtual plane 120x where the selected reference points 22 to 29 are closest to each other is determined by the least square method or the like. It is assumed using a method.
[0041]
Next, similarly to step # 15 of the first embodiment, the position specifying unit 5 specifies the point (measurement point projection point) 21a where the measurement point is reflected on the reference image by operating the input device 12 ( # 25). In the present embodiment, the shape of the same surface 120 where the measurement point 21 and the reference points 22 to 29 are present is unknown. Therefore, as in the first embodiment, the intersection of the surface 120, the center 100a of the optical axis, and the straight line L2 (light ray to the measurement point) connecting the measurement point (measurement point projection point) 21a on the reference image 110 is derived. Can not. Therefore, in the present embodiment, an intersection 21x between the virtual plane 120x and the straight line L2 obtained in the previous step # 24 is derived (# 26).
[0042]
As shown in FIG. 13, the intersection 21x is usually a point different from the actual measurement point 21. Therefore, the point projected on the inspection image 210 is not a true corresponding point. Therefore, in the present embodiment, a true corresponding point is obtained by the following processing. That is, first, as shown in FIG. 14, a section 41 having a predetermined width is set around the intersection 21x (# 27). It is preferable that the width of the setting section 41 can be arbitrarily adjusted according to the degree of bending of the surface 120, the reliability between the virtual plane 120x and the surface 120, and the like.
[0043]
Next, the section 41 on the light ray L2 is projected on the inspection image 210 (28). The light ray L2 is projected as an epipolar line 40 on the inspection image 210 as shown in FIG. The epipolar line 40 is extensive, extending to both ends of the inspection image 210, but can be limited to a narrow range by restricting the epipolar line 40 to the segmented region 41b on which the section 41 is projected. The area 41b can be arbitrarily adjusted by adjusting the predetermined width of the section 41 set in the previous step (# 27).
[0044]
As is clear from FIG. 15, when the true measurement point is included in the section 41 on the light ray L2 with respect to the measurement point, it is apparent that the true measurement point is included in the segmented area 41b where the setting section 41 is projected. It is. Therefore, the search area can be made smaller by making the neighborhood area of the divided area 41b a search area for correlation processing such as pattern matching, for example. The accuracy of the determination can be increased. More specifically, as shown in FIG. 17, an area 42 near the measurement point (projection point of the measurement point on the reference image) 21a specified in the reference image 110 is specified. Next, matching is performed on the pattern of the area 42a in the vicinity of the restricted divided area 41b of the inspection image 210, and the corresponding point 21b is determined.
[0045]
According to the present embodiment, even when the surface 120 on which the measurement point 21 is located is not a perfect plane, the search area on the inspection image can be reduced by using the virtually derived relational expression of the virtual plane. can do. Therefore, the burden of correlation processing such as pattern matching is reduced, and processing can be performed at high speed. In addition, matching errors can be reduced and accuracy can be increased.
[0046]
The present invention is not limited to the above embodiment, but can be implemented in various other modes.
[Brief description of the drawings]
FIG. 1 is a block diagram of a photogrammetry device according to an embodiment of the present invention.
FIG. 2 is a flowchart showing a flow of processing according to a first embodiment when photogrammetry is performed using the photogrammetry apparatus of FIG. 1;
FIG. 3 is a diagram showing a coordinate system when photogrammetry is performed using the apparatus of FIG. 1;
FIGS. 4A and 4B are diagrams illustrating examples of photographic images used for photogrammetry, wherein FIG. 4A is an example of a photographic image (reference image) of camera A100, and FIG. 4B is an example of a photographic image (inspection image) of camera B200. .
FIG. 5 is a diagram in which only reference points designated on the image shown in FIG. 4 are extracted.
FIG. 6 is an explanatory diagram of a process of selecting a reference point existing on a plane.
FIG. 7 is a diagram illustrating a positional relationship between measurement point projection points and measurement points placed on a reference image.
FIG. 8 is a view of FIG. 7 viewed from different angles.
FIG. 9 is a diagram showing a positional relationship when an intersection is projected on an inspection image.
FIG. 10 is a flowchart showing a flow of processing according to a second embodiment when photogrammetry is performed using the photogrammetry apparatus of FIG. 1;
FIG. 11 is an explanatory diagram of a process of selecting a reference point existing on a plane.
FIG. 12 is a diagram illustrating a relationship between a virtual plane and a surface.
FIG. 13 is a diagram illustrating a positional relationship between measurement point projection points and measurement points placed on a reference image.
FIG. 14 is an explanatory diagram of a process of setting a section having a predetermined width.
FIG. 15 is a diagram showing a positional relationship when a section is projected on an inspection image.
FIG. 16 is a diagram showing a segmented region of an epipolar line on an inspection image.
FIG. 17 is an explanatory diagram of pattern matching.
[Explanation of symbols]
L1, L2 Light rays for measurement points 1 Photogrammetry device 2 Bus 3 System program storage unit 4 Image storage unit 5 Position specification unit 6 Coordinate calculation unit 7 Plane calculation unit 8 Correlation processing unit 9 Calculation unit 20, 120 Surface 21 Measurement points (intersection points) )
21a Projection point of measurement point on reference image 21b Corresponding point (projection point of measurement point on inspection image)
21x Intersection points 22 to 30 of the virtual plane and the light rays Reference points 22a to 30a Projection points 22b to 30b of the reference point on the reference image Projection points 40 of the reference point on the inspection image Epipolar line 41 Setting section 41b Segmented area 100 Camera A ( Reference camera)
110 Reference image 120x Virtual plane 200 Camera B (inspection camera)
210 Inspection image

Claims (11)

Create a reference image and an inspection image respectively taken by a reference camera whose positional relationship is known and an inspection camera arranged at a position different from the reference camera, and a reference point arranged on a substantially plane on the reference image Are specified, a relational expression of the substantially plane is calculated based on the position of the reference point, a measurement point is specified in the substantially plane on the reference image, and the optical axis center of the reference camera and the measurement point And calculating a three-dimensional coordinate of an intersection where a straight line passing through the substantially plane intersects with the substantially plane, and determining a corresponding point of the measurement point on the inspection image based on the intersection, a measurement point in photogrammetry. How to match. When the substantially plane is a complete plane including the measurement points, the corresponding point of the measurement points on the inspection image is a point where the intersection point is projected on the inspection image. Item 1. The method of associating measurement points in photogrammetry according to item 1. The corresponding point of the measurement point on the inspection image is determined by performing a correlation process on the measurement point on the reference image and a predetermined area near the point where the intersection point is projected on the inspection image. The method according to claim 1, wherein the measurement points are associated with each other. 4. The method according to claim 3, wherein the size of the predetermined area is changeable. The relational expression of the plane is calculated based on the positional relationship between the reference camera and the inspection camera and the three-dimensional coordinates of the reference point calculated from coordinate values on the reference image and the inspection image of the three or more reference points. The method of associating measurement points in photogrammetry according to any one of claims 1 to 4, wherein: Reference point designating means for receiving an input of a plurality of reference points present on a substantially plane on a reference image and an inspection image whose relative positions are known from different positions,
Plane calculating means for calculating a relational expression of the substantially plane based on coordinate values of the input reference point on the reference image and the inspection image,
Measurement point designation means for designating a measurement point within the substantially plane on the reference image,
Intersection calculation means for calculating three-dimensional coordinates of an intersection at which a straight line passing through the optical axis center of the reference camera and the measurement point intersects the substantially plane,
And a corresponding point determining means for determining a corresponding point of the measurement point on the inspection image based on the intersection point. A computer is used to associate measurement points in photogrammetry.
A reference point designating means for receiving an input of a plurality of reference points present on a substantially flat surface on a reference image and an inspection image whose relative positions are known from different positions,
Plane calculating means for calculating a relational expression of the substantially plane based on coordinate values of the input reference point on the reference image and the inspection image,
Measurement point designating means for designating a measurement point within the substantially plane on the reference image,
Intersection calculation means for calculating three-dimensional coordinates of an intersection where a straight line passing through the optical axis center of the reference camera and the measurement point intersects the substantially plane,
Corresponding point determining means for determining a corresponding point of a measurement point on the inspection image based on the intersection;
A program for associating measurement points in photogrammetry to function as a computer. 8. The apparatus or program according to claim 6, wherein the corresponding point determining means sets a point where the intersection determined by the intersection calculating means is projected on the inspection image as a corresponding point. 9. The apparatus or the program according to claim 6, wherein the corresponding point determination unit projects the measurement point on the reference image and the intersection determined by the intersection calculation unit onto the inspection image. And performing a correlation process on a predetermined area near the measured point to determine a corresponding point of the measurement point on the inspection image. 10. The apparatus or the program according to claim 9, wherein the corresponding point determining means can change the size of the predetermined area. A storage medium storing the program according to any one of claims 7 to 10.

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