JP2010133752A - Shape measuring device and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To automatically obtain measurement values including an initial value necessary for three-dimensional shape measurement by automatically determining an erroneous corresponding point in an overlapping image. <P>SOLUTION: The shape measuring device 1 includes: image pickup parts 2 to 9 picking up images of a measurement object 18 in an overlapping image pickup area; a feature point correspondence part 21 for performing the correspondence of the positions of the feature points of the measurement object 18 in the overlapping image picked up by the image pickup parts 2 to 9; a triangulated net forming part 23 forming a triangulated net by connecting the feature points subjected to correspondence by the feature point correspondence part with each other by line segments; an erroneous corresponding point determination part 24 determining the erroneous corresponding on the basis of at least one of the length of a side, area, and angle of the triangulated net formed by the triangulated net forming part 23; and a three-dimensional shape measurement part 25 obtaining the three-dimensional shape of the measurement object 18 on the basis of the positions or the like of the feature points excluding the point determined as the erroneous corresponding point by the erroneous corresponding point determination part 24. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a shape measurement technique for measuring a three-dimensional shape of a measurement object based on overlapping images obtained by photographing the measurement object from a plurality of photographing positions, and in particular, an initial value necessary for measurement of the three-dimensional shape. The present invention relates to a technology for automatically acquiring measured values.

  Conventionally, the theory of photogrammetry has been studied. In recent years, a technique for measuring the three-dimensional shape of an object to be measured based on overlapping images taken from a plurality of shooting positions using the theory of photogrammetry has been disclosed. In order to measure the three-dimensional position of the measurement object, it is necessary to associate six or more points in the left and right images, but this processing must be performed manually or automatically by attaching a mark to the measurement object. was there.

  Further, in order to measure the three-dimensional shape of the measurement object, stereo matching is performed on the pixels of the measurement object. For stereo matching, least-square matching (LSM) for searching while deforming a template image, a normalized correlation method, or the like is used. This process requires many points and lines associated with the left and right images, but manually setting initial values of these points and lines is cumbersome and involves skills.

  For example, Patent Documents 1 and 2 disclose techniques for solving such problems. In the invention described in Patent Document 1, a pair of first photographed images obtained by photographing a measurement object provided with a reference feature pattern from different directions and a measurement object provided with no reference feature pattern are first. Based on a pair of second captured images captured from the same direction as the captured direction of one captured image, a feature pattern is extracted by taking the difference between the first captured image and the second captured image obtained in each direction.

  According to this aspect, since an image of only the feature pattern can be created, the position of the feature pattern can be automatically and accurately detected. Further, by increasing the number of feature pattern points, it is possible to automatically detect corresponding surfaces in the left and right images.

Further, in the invention described in Patent Document 2, position correction is performed between the photographing position of the measurement target and the reference position of the measurement target determined by the design data, and the three-dimensional shape of the measurement target is compared with the design data. , The miscorresponding points associated with each other are deleted. According to this aspect, the three-dimensional shape measurement process can be automated.
JP 10-318732 A JP 2007-212430 A

  In view of such a background, the present invention provides a technique for automatically acquiring measurement values including initial values necessary for measurement of a three-dimensional shape by automatically determining erroneous correspondence points in overlapping images. With the goal.

  According to the first aspect of the present invention, the imaging unit that images the measurement object in the overlapping imaging region from a plurality of imaging positions, and the position of the feature point of the measurement object in the overlapping image captured by the imaging unit A feature point association unit to be associated, a triangle network forming unit that connects the feature points associated by the feature point association unit with line segments to form a triangle network, and a side length of the triangle network formed by the triangle network formation unit A miscorresponding point determination unit that determines a miscorresponding point based on at least one of an area and an angle, a position of a feature point excluding a point determined as a miscorresponding point by the miscorresponding point determination unit, and the plurality of points A shape measuring apparatus comprising: a three-dimensional shape measuring unit for obtaining a three-dimensional coordinate of a feature point of the measurement object or a three-dimensional shape of the measurement object based on an imaging position.

  According to the first aspect of the present invention, it is possible to automatically acquire a measurement value including an initial value necessary for measuring a three-dimensional shape by automatically determining an erroneous correspondence point in an overlapping image.

  According to a second aspect of the present invention, in the first aspect of the present invention, based on the calibration subject provided with a reference point and the position of the corresponding reference point in a duplicate image obtained by photographing the calibration subject, the imaging And a photographing position / orientation measuring unit that obtains the photographing position and orientation of the unit.

  According to the second aspect of the present invention, the photographing position and orientation of the photographing unit are determined using the first method in which the calibration subject is photographed before photographing the measurement object and the position of the photographing unit is obtained in advance. Can be sought.

  The invention described in claim 3 is the invention described in claim 1, further comprising at least one of a horizontal angle measuring unit and a vertical angle measuring unit for measuring a shooting position of the shooting unit.

  According to the third aspect of the present invention, it is not necessary to obtain the photographing position and orientation of the photographing unit based on the image obtained by photographing the calibration subject.

  According to a fourth aspect of the present invention, in the first aspect of the present invention, the calibration subject provided with a reference point in a predetermined positional relationship and the position of the corresponding reference point in the overlapping image obtained by photographing the calibration subject. And a photographing position / orientation measuring unit for obtaining a photographing position and a posture of the photographing unit.

  According to the invention described in claim 4, by using the second method of photographing the calibration subject together with the measurement object and obtaining the position of the photographing unit and the three-dimensional position of the measurement object in parallel, The photographing position and posture of the photographing unit can be obtained.

  The invention according to claim 5 is the invention according to claim 1, wherein the miscorresponding point determination unit is configured such that when the triangle network forming unit forms a triangle network, a side length, an area, and an angle of the triangle mesh are formed. It is characterized in that a miscorresponding point is determined based on at least one of the above.

  According to the fifth aspect of the present invention, since the miscorresponding point is determined when forming the triangular network, the processing efficiency until the measurement value including the initial value necessary for measuring the three-dimensional shape is obtained. improves.

  The invention according to claim 6 is the invention according to claim 1, wherein the miscorresponding point determination unit deletes an edge based on the edge length of the triangle network, and then the number of isolated points connected is equal to or less than a predetermined value. Then, the isolated point is determined as an erroneous correspondence point.

  According to the sixth aspect of the present invention, the feature point group excluding the miscorresponding points can be a measured value including an initial value necessary for measuring the three-dimensional shape.

  The invention according to claim 7 is the invention according to claim 1, wherein the miscorresponding point determination unit is configured such that an area of a triangle in a triangle network is a predetermined value or more, and a vertex of the triangle is a contour of the measurement object. If it is a part, the vertex is determined to be a miscorresponding point.

  According to invention of Claim 7, the miscorresponding point of the outline part of a measurement object can be detected.

  The invention according to claim 8 is the invention according to claim 1, wherein the miscorresponding point determination unit is configured such that a triangle angle in the triangle network is equal to or less than a predetermined value, and a vertex of the triangle constituting the angle is the measurement. In the case of an outline portion of an object, the vertex is determined as an erroneous correspondence point.

  According to the eighth aspect of the invention, it is possible to detect an erroneous correspondence point of the contour portion of the measurement object.

  A ninth aspect of the invention is characterized in that, in the first aspect of the invention, the three-dimensional shape measurement unit measures a three-dimensional shape using the inside of the outline of the measurement object as a processing region.

  According to the ninth aspect of the present invention, an unnecessary three-dimensional shape is not formed in the contour portion of the measurement object.

  The invention according to claim 10 is the invention according to claim 9, wherein the three-dimensional shape measuring unit creates a convex hull of the feature point group excluding the miscorresponding points, and cuts the convex hull from the convex inward to the inside. Thus, the processing area is determined.

  According to the invention described in claim 10, an unnecessary three-dimensional shape is not formed in the concave contour portion of the measurement object.

  In the invention described in claim 11, in the invention described in claim 5, when the miscorresponding point determination unit determines that it is a miscorresponding point, the designation of the feature point corresponding to the miscorresponding point is canceled. It is characterized by being.

  According to the invention described in claim 11, the feature points excluding the miscorresponding points can be measured values including initial values necessary for measuring the three-dimensional shape.

  The invention according to claim 12 is the invention according to claim 1, in which the three-dimensional shape measuring unit performs processing for removing the erroneous corresponding point performed when the erroneous corresponding point determining unit obtains an initial value. It is comprised so that it may carry out when calculating | requiring a measured value after that.

  According to invention of Claim 12, the reliability of the measurement at the time of calculating | requiring a measured value in a three-dimensional shape measurement part improves.

  According to the thirteenth aspect of the present invention, the step of associating the feature points with the positions of the feature points of the measurement object in the overlapped images taken from a plurality of photographing positions and the feature points associated with each other at the feature point association step. Triangular network forming step for forming a triangular network by connecting line segments, and an erroneous corresponding point determining step for determining an erroneous corresponding point based on at least one of the side length, area, and angle of the triangular network formed in the triangular network forming step And the three-dimensional coordinates of the feature point of the measurement object or the measurement object based on the position of the feature point excluding the point determined as the incorrect correspondence point in the erroneous correspondence point determination step and the plurality of imaging positions. And a three-dimensional shape measuring step for obtaining a three-dimensional shape.

  According to the thirteenth aspect of the present invention, it is possible to automatically acquire a measurement value including an initial value necessary for measuring a three-dimensional shape by automatically determining an erroneous correspondence point in an overlapping image.

  According to the present invention, it is possible to automatically give a measurement value including an initial value necessary for measuring a three-dimensional shape by automatically determining an erroneous correspondence point in an overlapping image.

According to the present invention, the first method for obtaining the position of the photographing unit in advance of photographing the object to be measured and photographing the calibration object in advance and the position of the photographing unit together with the object to be photographed for photographing the calibration object. The second method can be applied in parallel. Examples applied to both of them will be described below.
1. First Embodiment Hereinafter, an example of a shape measuring apparatus and a program in which the present invention is applied to a first method will be described with reference to the drawings. In this first method, since the position and orientation of the photographing unit are first calculated from the calibration subject, two or more photographing units are fixed. The advantage of this method is that even when a moving object (for example, a living body) is measured, the measurement object can be captured and measured in an instant. In addition, once the position and orientation of the photographing unit is obtained from the calibration subject, three-dimensional measurement can be performed at any time by placing the measurement object in the space.

(Configuration of shape measuring device)
FIG. 1 is a top view of a shape measuring apparatus employing the first method. The shape measuring apparatus 1 includes photographing units 2 to 9, feature projecting units 10 to 13, a relay unit 14, a calculation processing unit 15, a display unit 17, and an operation unit 16. The shape measuring apparatus 1 measures the shape of the measuring object 18 disposed in the center of the imaging units 2 to 9.

  For the imaging units 2 to 9, for example, a video camera, a CCD camera for industrial measurement (Charge Coupled Device Camera), a CMOS camera (Complementary Metal Oxide Semiconductor Camera), or the like is used. The imaging units 2 to 9 are arranged around the measurement object 18. The imaging units 2 to 9 image the measurement object 18 in overlapping imaging areas from a plurality of imaging positions.

  The imaging units 2 to 9 are arranged in the horizontal direction or the vertical direction with a predetermined baseline length apart. Note that an imaging unit may be added and arranged in both the horizontal direction and the vertical direction. The shape measuring apparatus 1 measures the three-dimensional shape of the measuring object 18 based on at least a pair of overlapping images. Accordingly, the number of the photographing units 2 to 9 can be appropriately set to one or a plurality depending on the size and shape of the photographing subject.

  For example, a projector or a laser device is used for the feature projection units 10 to 13. The feature projection units 10 to 13 project a pattern such as a random dot pattern, dot spot light, or linear slit light onto the measurement target 18. Thereby, a feature enters a portion where the feature of the measurement object 18 is poor. The feature projection units 10 to 13 are arranged between the imaging units 2 and 3, between the imaging units 4 and 5, between the imaging units 6 and 7, and between the imaging units 8 and 9. In addition, when the measurement object 18 has a characteristic, or when a pattern is applied by application, the characteristic projection units 10 to 13 can be omitted.

  The imaging units 2 to 9 are connected to the relay unit 14 via an interface such as Ethernet (registered trademark), camera link, or IEEE 1394 (Institut of Electrical and Electronic Engineers 1394). As the relay unit 14, a switching hub or an image capture board is used. Images captured by the imaging units 2 to 9 are input to the calculation processing unit 15 via the relay unit 14.

  The calculation processor 15 is a personal computer (PC), or a PLD (Programmable Logic hardware using PLD such as Field Programmable Gate Array (FPGA) or Application Specific Integrated Circuit (ASIC). The calculation processing unit 15 is operated by the operation unit 16, and the processing contents and calculation results of the calculation processing unit 15 are displayed on the display unit 17. A keyboard and a mouse are used for the operation unit 16, and a liquid crystal monitor is used for the display unit 17. In addition, the operation unit 16 and the display unit 17 may be configured integrally with a touch panel type liquid crystal monitor.

  FIG. 2 is a block diagram of the shape measuring apparatus. The calculation processing unit 15 includes an imaging position / orientation measurement unit 20, a feature point association unit 21, a three-dimensional coordinate calculation unit 22, a triangle network formation unit 23, an incorrect corresponding point determination unit 24, and a three-dimensional shape measurement unit 25. These may be implemented as a module of a program that can be executed by a PC, or may be implemented as a PLD such as an FPGA.

  The imaging position / orientation measurement unit 20 measures external orientation elements (imaging positions and orientations) of the imaging units 2 to 9 based on an image obtained by imaging the calibration subject 19 shown in FIG. Note that if the internal orientation elements (principal point, focal length, and lens distortion) of the imaging units 2 to 9 are not known, the imaging position / orientation measurement unit 20 also obtains them simultaneously. The calibration subject 19 is a cubic calibration box in which a plurality of reference points are arranged.

  A color code target is used as the reference point (see Japanese Patent Application Laid-Open No. 2007-64627). The color code target has three retro targets (retroreflective targets). First, the photographing position / orientation measurement unit 20 binarizes an image obtained by photographing the calibration subject 19, thereby detecting a retro target and obtaining its center-of-gravity position (reference point image coordinates). The photographing position / orientation measurement unit 20 labels each reference point based on the color code target color scheme (color code). Thereby, the position of the corresponding reference point in the overlapping image is known.

  Then, the photographing position / orientation measurement unit 20 calculates the external orientation elements of the photographing units 2 to 9 by using the relative orientation method, the single photograph orientation method, the DLT method, or the bundle adjustment method. These may be used alone or in combination. The first method will be described in detail in this embodiment, and the second method will be described in detail in the third embodiment.

  In this first method, since the position and orientation of the photographing units 2 to 9 are first calculated by the calibration subject 19, two or more photographing units 2 to 9 are fixed. The advantage of this method is that even when a moving object (for example, a living body) is measured, the measurement object 18 can be captured and measured in an instant. In addition, once the position and orientation of the photographing units 2 to 9 are obtained from the calibration subject 19, three-dimensional measurement can be performed at any time by placing the measurement object 18 in the space.

  The feature point association unit 21 extracts feature points of the measurement object 18 from at least a pair of stereo images, and associates the positions of the feature points in the stereo image. When the photographing units 2 to 9 are arranged in the horizontal direction, the feature point association unit 21 searches for the position of the feature point in the horizontal direction, and when the photographing units 2 to 9 are arranged in the vertical direction. When the position of the feature point is searched in the vertical direction and the photographing units 2 to 9 are arranged in the horizontal direction and the vertical direction, the position of the feature point is searched in the horizontal direction and the vertical direction.

  The feature point association unit 21 includes a background removal unit 26, a feature point extraction unit 27, and a corresponding point search unit 28. The background removal unit 26 generates a background removal image in which only the measurement object 18 is copied by subtracting the background image from the processed image in which the measurement object 18 is copied.

  The feature point extraction unit 27 extracts feature points from the background removed image. At this time, feature points are extracted from the left and right stereo images in order to limit the search range of corresponding points. As a feature point extraction method, a differential filter such as Sobel, Laplacian, Prewitt, or Roberts is used.

  The corresponding point search unit 28 searches for a corresponding point corresponding to the feature point extracted in one image in the other image. As a corresponding point search method, template matching such as a residual sequential detection method (Sequential Similarity Detection Method: SSDA), a normalized correlation method, a direction code matching method (Orientation Code Matching: OCM), or the like is used.

  The three-dimensional coordinate calculation unit 22 is based on the external orientation elements measured by the shooting position / orientation measurement unit 20 and the image coordinates of the feature points associated by the feature point association unit 21. Calculate 3D coordinates.

  The triangle network forming unit 23 forms an irregular triangular network (TIN) in which the feature points associated by the feature point association unit 21 are connected by line segments. The Delaunay method is used to form the triangular network. The triangular network is formed based on the image coordinates of the feature points associated by the feature point association unit 21 or the 3D coordinates obtained by the 3D coordinate calculation unit 22.

  The miscorresponding point determination unit 24 includes at least one of a side length determination unit 29, an area determination unit 30, and an angle determination unit 31. The miscorresponding point determination unit 24 determines the miscorresponding point based on at least one of the side length, the area, and the angle of the triangular mesh when the triangular mesh forming unit 23 forms or after the forming. When it is determined that the feature point is a miscorresponding point, the designation of the feature point is canceled.

  The side length determination unit 29 deletes the side when the triangular network forming unit 23 forms or the side length of the formed triangular network is equal to or smaller than a predetermined value, and the number of isolated points connected is equal to or smaller than the predetermined value. If so, the isolated point is determined to be a miscorresponding point.

  The area determination unit 30 incorrectly corresponds to a vertex formed by the triangle network forming unit 23 or when the area of the formed triangle is equal to or larger than a predetermined value and the vertex of the triangle is the contour portion of the measurement object. Judge as a point.

  The angle determination unit 31 is formed by the triangle network forming unit 23, or when the angle of the formed triangle is equal to or less than a predetermined value, if the vertex of the triangle constituting the angle is the contour part of the measurement object, The vertex is determined as an erroneous correspondence point.

  The three-dimensional shape measurement unit 25 performs stereo matching on the pixels in the predetermined region using the feature point group excluding the points determined as the erroneous correspondence points by the erroneous correspondence point determination unit 24, and Find the 3D shape. For stereo matching, LSM that searches while deforming a template image, a normalized correlation method, or the like is used. The three-dimensional shape is displayed on the display unit 17 as a point cloud or TIN.

  Furthermore, the process of removing the miscorresponding point performed when the miscorresponding point determination unit 24 obtains the initial value can be similarly performed when the three-dimensional shape measuring unit 25 subsequently obtains the measurement value. .

(Processing of shape measuring device)
Hereinafter, detailed processing of the shape measuring apparatus will be described with reference to FIG. FIG. 3 is a flowchart of the program of the shape measuring apparatus. The program for executing this flowchart can be provided by being stored in a recording medium such as a CDROM.

  First, a processed image and a background image are input (step S10). Next, the background removal unit 26 removes the background of the measurement target 18 (step S11). FIG. 4 is a drawing substitute photo (A) showing a processed image, a drawing substitute photo (B) showing a background image, and a drawing substitute photo (C) showing a background removed image. The background removed image is generated by subtracting the background image from the processed image. Background removal is performed on the left and right images. Note that this process may not be performed if a background image cannot be obtained.

  Next, feature points are extracted from the left and right images by the feature point extraction unit 27 (step S12). By extracting feature points from the left and right images, the search range for corresponding points can be reduced.

The feature point extraction unit 27 performs preprocessing such as reduction processing, brightness correction, and contrast correction as necessary (step S12-1). Next, the edge strength is calculated from the preprocessed left and right images by the Sobel filter (step S12-2). FIG. 5 shows Sobel filters in the x and y directions. When the luminance values of nine pixels corresponding to the matrix of the Sobel filter are I _{1 to} I ₉ from the upper left to the lower right, the intensity in the x direction is dx, and the intensity in the y direction is dy, the target pixel (center The edge intensity Mag of the pixel is calculated by the following equation (1).

  FIG. 6 is a drawing-substituting photograph (A) showing an input image subjected to 1/4 compression, and a drawing-substituting photograph (B) showing an edge strength image obtained by a Sobel filter. The feature point extraction unit 27 performs post-processing such as thinning the edge intensity image in FIG. 6B (step S12-3). By thinning, the edge becomes one pixel width. As a result, since the positions of the feature points finally extracted are thinned out, the feature points are extracted without deviation in the image.

  Next, the feature point extraction unit 27 performs binarization processing (step S12-4). In order to automatically determine the binarization threshold, a histogram of edge strength is created. FIG. 7 is a histogram of edge strength. The feature point extraction unit 27 uses, as a binarization threshold, an edge intensity corresponding to a position where the cumulative frequency counted from the edge having the stronger edge intensity is 50% of the total number of edge pixels in the created histogram.

  In the case of FIG. 7, the number of pixels of the edge is 56986 pixels, and the edge strength at the 28493th pixel where the cumulative frequency counted from the stronger side is 50% of the total number of edge pixels is 52. Therefore, the binarization threshold is 52. FIG. 8 is a drawing substitute photograph showing the result of binarization with the threshold 52, and FIG. 9 is a drawing substitute photograph showing the feature points extracted in the left and right images.

  Next, the corresponding point search unit 28 associates feature points in the left and right images (step S13). The corresponding point search unit 28 creates a template image centered on each feature point in the left image, and searches for a corresponding point having the strongest correlation with the template image in a predetermined region in the right image.

  FIG. 10 is an explanatory diagram (A) for explaining the template creation method, an explanatory diagram (B) for explaining the search line determination method, and an explanatory diagram (C) for explaining the search width determination method. As shown in FIG. 10A, the template image is composed of 21 pixels × 21 pixels centered on the feature point of interest. Since the vertical parallax is removed from the stereo image, a search line is provided in parallel to the x-axis as shown in FIG. Also, as shown in FIG. 10C, the corresponding point search unit 28 detects the leftmost feature point and the rightmost feature point on the search line of the right image, and the leftmost feature point and the rightmost feature point. Corresponding points are searched using the search range up to the feature point of.

  As a result, the point having the strongest correlation with the template image becomes the corresponding point. When the photographing units 2 to 9 are arranged in the vertical direction, the search line is parallel to the y axis. When the photographing units 2 to 9 are arranged in the vertical direction and the horizontal direction, the search lines are the x axis and the y axis.

  Next, the miscorresponding point determination unit 24 determines a feature point (miscorresponding point) that is incorrectly associated (step S14). The miscorresponding point determination processing includes determination based on the TIN side length (step S14-1), determination based on the TIN area (step S14-2), and determination based on the TIN angle (step S14-3). . These determination processes are performed in stages, but may be an aspect in which at least one process is performed.

  Hereinafter, a determination method based on the TIN side length will be described (step S14-1). First, the triangle network forming unit 23 forms a TIN two-dimensionally or three-dimensionally based on the position of the feature point associated by the feature point association unit 21. FIG. 11 is an explanatory diagram for explaining a TIN formation procedure. A Delaunay method is used to form TIN.

  As shown in FIG. 11A, it is assumed that there are six feature points P1 to P6. If P1 is an attention point (mother point), first, a feature point (P2) closest to P1 is searched. At this time, a perpendicular bisector B1 connecting the line connecting P1 and P2 is drawn. This boundary line between P1 and P2 is called a Voronoi boundary.

  Next, a feature point (P3) closest to P2 is searched. At this time, since the perpendicular bisector (not shown) connecting P1 and P3 is located farther from the base point P1 than the Voronoi boundary B1 that has already been created, no Voronoi boundary is created.

  Next, the feature point (P4) closest to P3 is searched. At this time, a vertical bisector B2 connecting the line connecting P1 and P4 is drawn. The Voronoi boundary B2 is created because it is closer to the mother point P1 than the Voronoi boundary B1. As described above, feature points close to P1 are searched, and Voronoi boundaries B1 to B3 are created. A region surrounding the generating point P1 by Voronoi boundaries B1 to B3 is called a Voronoi region.

  When this process is performed on all the feature points P1 to P6, a Voronoi region shown in FIG. 11B is generated. Then, TINs are formed by connecting the generating points of adjacent Voronoi regions. A side of TIN is called a Delaunay side, and a polygon formed by the Delaunay side is called a Delaunay polygon. Delaunay polygons are usually triangular.

  The side length determination unit 29 determines an erroneous correspondence point based on the side length of the TIN when the triangular net forming unit 23 forms the TIN or after the TIN is formed. FIG. 12 is a drawing-substituting photograph showing a TIN created with a mesh interval of 10 mm, and FIG. 13 is a drawing-substituting photograph showing a result of removing a TIN having a long side. As shown in FIG. 12, when the mesh interval is set to 10 mm, TIN having a side of 40 mm or more, which is four times as large, is removed. The threshold value of the side length of 4 times the mesh interval is an experimentally determined value and can be changed in advance.

  As shown in FIG. 13, as a result of removing the TIN having a long side, a TIN lump separated from the main part is generated. Since the separated TIN lump is often a background or a hair portion with few features even if the side length is short, the reliability of the surface of the measurement object 18 is low. Therefore, the side length determination unit 29 performs labeling for each TIN chunk, and removes the TIN chunk based on the number of connections.

  FIG. 14 is a drawing-substituting photograph showing the TIN labeling result. The side length determination unit 29 determines that a TIN block having a labeling connection number of 10 or less is a miscorresponding point. The designation of the feature points constituting the TIN chunk is canceled. Note that the threshold of the number of labeling connections can be changed in advance.

  Next, a determination method based on the area of TIN will be described (step S14-2). FIG. 15 is an explanatory diagram illustrating a procedure for determining an erroneous corresponding point based on the area of the TIN. As shown in FIG. 15A, the area determination unit 30 first searches for a triangle P1P2P4 in which the area S of each triangle is greater than or equal to a predetermined value. Next, it is determined whether or not the vertex of the triangle is the contour portion of the measuring object 18.

  As shown in FIG. 15B, whether or not there is a feature point connected to P1 outside the triangle P1P2P4 and in a predetermined angle centered on P1 and the arc region T1 in the direction of the side P1P4 or the side P1P2 Judging. When there is no feature point connected to the circular arc region T1, it is determined that P1 is a contour portion of the measuring object 18. Note that the angle and direction of the arc region T1 can be changed in advance.

  This process is performed for each vertex P1P2P4 of the triangle. In the case of FIG. 15B, since there is no feature point in the arc region T1 of P1 and the arc region T2 of P2, P1 and P2 are determined to be the contour portions of the measurement object 18, and are determined to be miscorresponding points. Is done. As shown in FIG. 15C, the designation of feature points for P1 and P2 determined to be miscorresponding points is cancelled.

  FIG. 16 is a drawing-substituting photograph showing the result of removing a large area TIN. FIG. 16 shows the result of only the determination of the miscorresponding point based on the area, and does not determine the miscorresponding point based on the side length. Note that the area determination unit 30 determines a miscorresponding point when the triangular net forming unit 23 forms a TIN or after the TIN is formed.

  Next, a determination method based on the TIN angle will be described (step S14-3). FIG. 17 is an explanatory diagram illustrating a procedure for determining an erroneous corresponding point based on a TIN angle. As shown in FIG. 17A, the angle determination unit 31 first searches for a triangle P3P4P6 in which the angle θ of each triangle is a predetermined value or less. Next, if the apex P3 of the triangle that forms the angle θ is the contour portion of the measurement object, the apex is determined as an erroneous correspondence point.

  As shown in FIG. 17B, whether or not there is a feature point connected to P3 outside the triangle P3P4P6 and in a predetermined angle centered on P3 and the arc region T3 in the direction of the side P3P4 or the side P3P6 Judging. When there is no feature point connected to the circular arc region T3, P3 is determined to be an outline portion of the measurement object 18, and is determined to be a miscorresponding point. Note that the angle and direction of the arc region T3 can be changed in advance.

  As shown in FIG. 17C, the designation of the feature point is canceled for P3 determined to be a miscorresponding point. This process is performed for the vertices of a triangle whose angle θ is a predetermined value or less. FIG. 18 is a drawing-substituting photograph showing the result of removing TIN having a small angle. FIG. 18 shows the result of only the determination of the miscorresponding point based on the angle, and the miscorresponding point is not determined based on the side length or area. Note that the angle determination unit 30 determines an erroneous correspondence point when the triangular net forming unit 23 forms a TIN or after the TIN is formed.

  FIG. 19 is a drawing-substituting photograph showing the result of removing TIN by the side length, area, and angle of TIN. By making all the determinations of miscorresponding points based on the side length, area, and angle of the TIN, a TIN composed only of highly accurate feature points is formed.

  When the determination of the miscorresponding point regarding the initial value is completed, the three-dimensional shape of the measurement object is measured by the three-dimensional shape measurement unit 25 (step S15). The three-dimensional shape measurement unit 25 performs stereo matching using a feature point group excluding points determined to be miscorresponding points as an initial value of LSM, and measures a three-dimensional shape (dense surface). FIG. 20 is a drawing-substituting photograph showing the result of dense surface measurement. In FIG. 20, the processing area of LSM is a convex area in which the feature point group after removing the miscorresponding points is surrounded by a convex hull. For this reason, an unnecessary TIN is generated from the head to the shoulder, but a TIN having a specified mesh interval is generated in the portion of the random dot pattern projected by the feature projection units 10 to 13.

  FIG. 21 is a drawing-substituting photograph showing measurement results of a three-dimensional shape in a plurality of models. When a plurality of models shown in FIG. 21 are synthesized, an unnecessary TIN that connects the head to the shoulder formed in the front model hides the original surface formed in the side model. Therefore, the processing area of the LSM is limited so as not to generate unnecessary TIN formed from the head to the shoulder.

  FIG. 22 is a diagram illustrating restrictions on the processing area of LSM. As shown in FIG. 22, the enclosing line of the feature point group is created. The encircling line is created by creating a convex hull line and repeating the process of cutting the processing area inward while looking at the distance and angle between the constituent points.

  The process of removing the miscorresponding point performed when the initial value is obtained by the miscorresponding point determination unit can be similarly performed when the three-dimensional shape measuring unit 25 subsequently obtains the measured value.

  FIG. 23 is a drawing-substituting photograph showing the measurement result of adjusting the LSM processing area, and FIG. 24 is a drawing-substituting photograph showing the synthesis result of the plurality of models in FIG. As shown in FIGS. 23 and 24, it can be seen that unnecessary TIN is removed from the head to the shoulder.

  Hereinafter, an example of specific processing when the photographing position / orientation measuring unit 20 adopts the relative orientation method in the first method of photographing the calibration subject before photographing the measurement object and obtaining the position of the photographing unit in advance. Is described below.

  According to the relative orientation method, an external orientation element can be obtained based on six or more corresponding reference points copied in the overlapping image. If the three-dimensional position of the reference point is known, the absolute coordinates of the photographing units 2 to 9 are obtained by absolute orientation.

FIG. 25 is an explanatory diagram for explaining relative orientation. In the relative orientation, an external orientation element is obtained from six or more corresponding points (pass points) in the two left and right images. In the relative orientation, a coplanar condition that two rays connecting the projection centers O ₁ and O ₂ and the reference point P must be in the same plane is used. The following formula 2 shows the coplanar conditional expression.

As shown in FIG. 25, the origin of the model coordinate system is taken as the left projection center O ₁ , and the line connecting the right projection center O ₂ is taken as the X axis. For the scale, the base length is the unit length. At this time, the parameters to be obtained are the rotation angle κ ₁ of the left camera, the rotation angle φ _{1 of} the Y axis, the rotation angle κ _{2 of the} right camera, the rotation angle φ ₂ of the Y axis, and the rotation angle φ _{2 of} the X axis. There are five rotation angles ω ₂ . In this case, since the rotation angle ω ₁ of the X axis of the left camera is 0, there is no need to consider it. Under such a condition, the coplanar conditional expression of Expression 2 becomes as shown in Expression 3, and each parameter can be obtained by solving this expression.

  Here, the following relational expression for coordinate transformation is established between the model coordinate system XYZ and the camera coordinate system xyz.

Using these equations, an unknown parameter (external orientation element) is obtained by the following procedure.
(1) The initial approximate values of unknown parameters (κ ₁ , φ ₁ , κ ₂ , φ ₂ , ω ₂ ) are normally 0.
(2) The coplanar conditional expression of Equation 3 is Taylor-expanded around the approximate value, and the value of the differential coefficient when linearized is obtained by Equation 4, and an observation equation is established.
(3) A least square method is applied to obtain a correction amount for the approximate value.
(4) The approximate value is corrected.
(5) Using the corrected approximate value, the operations (1) to (4) are repeated until convergence.

When the relative orientation converges, connection orientation is further performed. Connection orientation is a process of unifying the inclination and scale between a plurality of models to make the same coordinate system. When this processing is performed, a connection range represented by the following formula 5 is calculated. As a result of the calculation, if ΔZ _j and ΔD _j are equal to or less than a predetermined value (for example, 0.0005 (1/2000)), it is determined that the connection orientation has been normally performed.

(Advantages of the first embodiment)
According to the first embodiment, by automatically determining the miscorresponding points in the left and right overlapping images, the measurement value including the initial value of LSM or normalized correlation method used for stereo matching is automatically acquired. Can do.

  Further, by limiting the processing region for stereo matching, only the original shape of the measurement object 18 can be formed, and a plurality of models can be synthesized.

  Further, the photographing position and orientation of the photographing units 2 to 9 can be measured by the calibration subject 19. After obtaining the photographing position and orientation, three-dimensional measurement can be performed at any time by placing the measuring object 18 in the space. Further, even a dynamic measurement object 18 having movement can be measured by simultaneously photographing with the photographing units 2 to 9.

2. Second Embodiment Hereinafter, a modification of the first embodiment will be described. The second embodiment further includes a contour extraction unit that extracts the contour of the measurement object.

  FIG. 28 is a block diagram of a shape measuring apparatus according to the second embodiment. The calculation processing unit 15 of the shape measuring apparatus includes a contour extraction unit 37 between the background removal unit 26 and the feature point extraction unit 27. First, the contour extraction unit 37 creates an edge intensity image of the measuring object 18 using a differential filter such as Sobel, Laplacian, Plewwit, and Roberts.

  Next, the contour extraction unit 37 performs a labeling process on the image obtained by thinning the edge strength image, and obtains the length of the edge from the number of connected pixels. A contour edge is extracted by binarizing a value obtained by multiplying the edge strength and the edge length. FIG. 29A is a drawing-substituting photograph showing a contour edge. The contour edge 38 has a strong edge strength and a large amount of linear components compared to the internal features of the measurement object 18.

  The feature point extraction unit 27 extracts feature points in a region inside the contour edge 38 extracted by the contour extraction unit 37. FIG. 29B is a drawing-substituting photograph (B) showing a feature point extraction region. The extraction region 39 is a region having a predetermined ratio (for example, 80%) of the lateral width of the contour edge. This value of 80% can be changed in advance.

(Advantage of the second embodiment)
FIG. 30 is a drawing-substituting photograph showing a difference in photographing range of stereo images. As shown in FIG. 30, in the stereo image, there is a left image shooting range 40 that does not appear in the right image and a right image shooting range 41 that does not appear in the left image. Since the feature points extracted in the photographing regions 40 and 41 cannot be associated with the feature points, they are all false correspondence points. However, according to the second embodiment, since the feature point extraction region is limited, no erroneous corresponding point is extracted.

3. Third Embodiment The third embodiment is based on a second method in which the position of the photographing unit is photographed in parallel with the object to be measured, and a reference scale (calibration subject) is obtained in parallel. It is a modification of the processing method of the imaging position and orientation measurement unit 20 in the embodiment.

  The second method is a method in which a subject to be measured and a calibration subject are imprinted at the same time, and the position and orientation of the photographing unit are obtained to perform three-dimensional measurement. In this case, there is no need to fix the photographing unit, and there may be one to a plurality of photographing units, and measurement is possible if the number of photographing is two or more. The advantage of this method is that the position of the photographing unit is free and can be measured even from one unit, so that the configuration can be simplified. In addition, since the position and orientation of the photographing unit are obtained at the same time as the measurement object is photographed, it is not necessary to obtain the position and orientation of the photographing unit in advance. The calibration subject to be imaged together uses a fixed length such as a reference scale, or a fixed coordinate.

  The shooting part does not need to be fixed basically and can be placed anywhere. FIG. 31 is a top view of the shape measuring apparatus according to the third embodiment, and FIG. 32 is a top view of a modification of the shape measuring apparatus according to the third embodiment. FIG. 31 shows the relationship between the reference rule 19, the imaging unit 2 and the measurement object 18, the measurement processing unit 15, the operation unit 16, and the display unit 17 in a mode in which shooting is performed with one imaging unit moving. ing. FIG. 32 shows a modification in a mode in which two cameras have a stereo camera configuration or a plurality of cameras have a multi-camera configuration.

  In this case, the measurement processing unit 15, the operation unit 16, and the display unit 17 can be configured by only the photographing unit and the PC by using the PC. If there is no pattern on the object, the pattern is projected by a projector or a pattern is applied to the object. As a method for obtaining the photographing position and orientation of the photographing unit, a relative orientation method, a single photo orientation method, a DLT method, or a bundle adjustment method is used, and these may be used alone or in combination.

  If the photographing position and orientation (external orientation element) of the photographing unit are obtained by single photograph orientation or the DLT method, the external orientation element can be obtained based on the relative positional relationship of the reference points captured in one photograph. it can.

  FIG. 33 is a drawing substitute photo (A) showing a left image obtained by photographing a reference scale and a measurement object, and a drawing substitute photo (B) showing a right image. As shown in FIG. 33, the measurement object 18 is photographed with a reference scale 35 (calibration subject) in which the color code targets 36a to 36d are arranged in a relative positional relationship.

  The imaging position / orientation measurement unit 20 illustrated in FIG. 2 acquires the overlapping image illustrated in FIG. The photographing position / orientation measurement unit 20 binarizes the overlapping images to obtain the barycentric positions (image coordinates of the reference points) of the color code targets 36a to 36d. The photographing position / orientation measurement unit 20 reads a color code from the color scheme of the color code targets 36a to 36d, and labels each color code target 36a to 36d.

  With this label, the correspondence of the reference points in the overlapping image can be known. The photographing position / orientation measuring unit 20 uses the mutual orientation method, single photo orientation or DLT method, or bundle adjustment method based on the image coordinates of the reference point and the relative positional relationship of the reference points in three dimensions. Obtain the shooting position and posture of ~ 9. A combination of these also requires a highly accurate position and orientation.

  The second method, which is the processing method of the photographing position / orientation measurement unit 20 employed in the present embodiment, is a modification of the first method employed in the first embodiment, and for other configurations and processes, the first method is used. The configuration and processing shown in the fifth embodiment can be adopted.

(Advantage of the third embodiment)
According to the third embodiment, the second method is adopted, and the position and orientation of the photographing unit can be obtained and three-dimensional measurement can be performed by photographing the measurement object 18 and the calibration subject 19 at the same time. The imaging unit can be configured from one unit to any number of units, and since it is not necessary to fix the imaging unit, the configuration can be simplified.

4). Fourth Embodiment In the first embodiment that employs the first method, an example has been described in which the photographing position / orientation measurement unit 20 obtains the photographing position and orientation of the photographing unit using the relative orientation method. In the embodiment, single photograph orientation and DLT method will be described as examples of specific processing that can be adopted instead of the relative orientation method.

4-1. Single photograph orientation FIG. 27 is an explanatory diagram for explaining single photograph orientation. Single photo orientation uses the collinear condition that holds the reference point in a single photo, and uses the camera position O (X ₀ , Y ₀ , Z ₀ ) and camera posture (ω , Φ, κ). The collinear condition is a condition that the projection center, the photographic image, and the ground target points (Op ₁ P ₁ , Op ₂ P ₂ , Op ₃ P ₃ ) are on a straight line. The camera position O (X ₀ , Y ₀ , Z ₀ ) and the camera posture (ω, φ, κ) are external orientation elements.

  First, the camera coordinate system is x, y, z, the photographic coordinate system x, y, and the ground coordinate system is X, Y, Z. It is assumed that photographing is performed in a direction in which the camera is sequentially rotated counterclockwise by ω, φ, and κ counterclockwise with respect to the positive direction of each coordinate axis. Then, the four-dimensional image coordinates (at least three points) and the corresponding three-dimensional coordinates of the reference point are substituted into the quadratic projective transformation equation shown in Equation 6, and the observation equation is established to obtain the parameters b1 to b8.

Using the parameters b1 to b8 in Equation 6, an external orientation element is obtained from Equation 7 below.

4-2. DLT method The DLT method approximates the relationship between the photographic coordinates and the three-dimensional coordinates of the target space by a cubic projective transformation equation. The basic formula of the DLT method is the following formula 8. For details of the DLT method, refer to “Shunji Murai: Analytical Photogrammetry, p46-51, p149-155” and the like.

  If the denominator of the equation (8) is eliminated, the line form of the equation (9) can be derived.

  Furthermore, when Equation 9 is transformed, the following Equation 10 is obtained.

By substituting the three-dimensional coordinates of six or more reference points into Equation 10 and solving using the least square method, eleven unknown variables L _{1 to} L ₁₁ that determine the relationship between the photograph coordinates and the target point coordinates are obtained. You can get it. Note that L _{1 to} L ₁₁ include external orientation elements.

(Advantage of the fourth embodiment)
According to the fourth embodiment, when single photograph orientation is adopted, it is advantageous for measurement from a small number of images, and when DLT is adopted, there is an advantage that arithmetic processing is simpler than single photograph orientation. is there.

5). Fifth Embodiment Hereinafter, in the first embodiment, in the first embodiment, as a method for obtaining the position and orientation of the photographing unit, at least one of a horizontal angle measuring unit and a vertical angle measuring unit is used. A means for measuring the photographing position is employed.

  FIG. 26 is a top view of a shape measuring apparatus having a horizontal angle measuring unit. The horizontal angle measuring unit 32 is a rotary encoder, and includes a horizontal angle scale 33 and an encoder 34. The photographing units 2 to 9 can be fixed at an arbitrary position of the horizontal angle scale 33, and the photographing units 2 to 9 and the horizontal angle scale 33 are integrally supported so as to be rotatable clockwise and counterclockwise. . On the other hand, the encoder 34 is fixed at an arbitrary position on the circumference of the horizontal angle scale 33.

  The horizontal angle scale 33 includes imaging unit detection patterns 33a to 33d and horizontal angle detection slits 33e. The imaging unit detection patterns 33a to 33d are detachable at arbitrary positions on the circumference of the horizontal angle scale 33, and are mounted at positions where the imaging units 2 to 9 are fixed. For example, the image capturing unit detection patterns 33a to 33d are arranged between the image capturing units 2 and 3, the image capturing units 4 and 5, the image capturing units 6 and 7, the image capturing units 8 and 9, and the image capturing units 2 and 4. , 6 and 8 are installed.

  When the imaging units 2 to 9 and the horizontal angle scale 33 rotate, the encoder 34 detects the imaging unit detection patterns 33a to 33d. At this time, the encoder 34 sets the horizontal angle of the position of the pattern detected first among the imaging unit detection patterns 33a to 33d to zero. Then, the encoder 34 detects the horizontal angle from there to the other imaging unit detection patterns 33a to 33d by the horizontal angle detection slit 33e.

  When the imaging units 2 to 9 adjust the height so as to rotate on the same horizontal plane, the imaging positions of the imaging units 2 to 9 are obtained based only on the horizontal angle detected by the encoder 34. The encoder 34 outputs the horizontal angles of the photographing units 2 to 9 to the calculation processing unit 15. The calculation processing unit 15 obtains a relative three-dimensional shooting position of the shooting units 2 to 9 based on the input horizontal angle of the shooting units 2 to 9. Further, when obtaining the photographing positions of the real scale photographing units 2 to 9, the calculation processing unit 15 inputs the diameter of the horizontal angle scale 33.

  Further, the shape measuring apparatus 1 may include a vertical angle measuring unit that rotates in the vertical direction integrally with the imaging units 2 to 9 instead of the horizontal angle measuring unit 32. In this case, the calculation processing unit 15 obtains the photographing positions of the photographing units 2 to 9 based on the vertical angle detected by the vertical angle measuring unit.

  Further, the shape measuring apparatus 1 may be configured to include a vertical angle measuring unit that rotates integrally with the imaging units 2 to 9 and the horizontal angle measuring unit 32 in the vertical direction. In this case, the calculation processing unit 15 obtains the photographing position of the photographing units 2 to 9 based on the horizontal angle and the vertical angle of the photographing units 2 to 9.

(Advantage of the fifth embodiment)
According to the fifth embodiment, it is not necessary to obtain the shooting positions and postures of the shooting units 2 to 9 based on the image obtained by shooting the calibration subject 19. That is, the shape measuring apparatus 1 does not need to include the photographing position / orientation measuring unit 20.

  The present invention can be used for a shape measuring apparatus and a program for measuring a three-dimensional shape of a measurement object.

It is a top view of the shape measuring apparatus to which the first method is applied. It is a block diagram of the shape measuring device concerning a 1st embodiment. It is a flowchart of a shape measuring apparatus. A drawing substitute photo (A) showing a processed image, a drawing substitute photo (B) showing a background image, and a drawing substitute photo (C) showing a background removed image. It is a Sobel filter in the x and y directions. They are a drawing substitute photo (A) showing an input image subjected to 1/4 compression, and a drawing substitute photo (B) showing an edge strength image by a Sobel filter. It is a histogram of edge intensity. 5 is a drawing substitute photograph showing the result of binarization with a threshold value 52. FIG. It is a drawing substitute photograph showing the feature points extracted in the left and right images. It is explanatory drawing (A) explaining the template preparation method, explanatory drawing (B) explaining the determination method of a search line, and explanatory drawing (C) explaining the determination method of search width. It is explanatory drawing (A)-(C) explaining the formation procedure of TIN. It is a drawing substitute photograph which shows TIN created with the mesh space | interval of 10 mm. It is a drawing substitute photograph which shows the result of removing TIN having a long side. It is a drawing substitute photograph which shows the labeling result of TIN. It is explanatory drawing (A)-(C) explaining the determination procedure of the miscorresponding point by the area of TIN. It is a drawing substitute photograph showing the result of removing TIN having a large area. It is explanatory drawing (A)-(C) explaining the determination procedure of the miscorresponding point by the angle of TIN. It is a drawing substitute photograph which shows the result of removing TIN having a small angle. It is a drawing substitute photograph which shows the removal result of TIN by the side length, area, and angle of TIN. It is a drawing substitute photograph which shows the result of dense surface measurement. It is a drawing substitute photograph which shows the measurement result of the three-dimensional shape in a some model. It is a figure which shows the restriction | limiting of the process area | region of LSM. It is a drawing substitute photograph which shows the measurement result which adjusted the process area | region of LSM. It is a drawing substitute photograph which shows the synthetic | combination result of the several model of FIG. It is explanatory drawing explaining a relative orientation. It is a top view of the shape measuring apparatus which concerns on 5th Embodiment. It is explanatory drawing explaining a single photograph orientation. It is a block diagram of the shape measuring apparatus which concerns on 2nd Embodiment. It is drawing substitute photograph (A) which shows an outline edge, and drawing substitute photograph (B) which shows the extraction area | region of a feature point. It is a drawing substitute photograph which shows the difference in the imaging | photography range of a stereo image. It is a top view of the shape measuring apparatus which concerns on 3rd Embodiment. It is a top view of the modification of the shape measuring apparatus which concerns on 3rd Embodiment. It is drawing substitute photograph (A) which shows the left image which image | photographed the reference | standard scale and the measuring object, and drawing substitute photograph (B) which shows a right image.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Shape measuring apparatus, 2-9 ... Imaging | photography part, 10-13 ... Feature projection part, 14 ... Relay part, 15 ... Calculation processing part, 16 ... Operation part, 17 ... Display part, 18 ... Measurement object, 19 ... Calibration subject, 20 ... shooting position / orientation measurement unit, 21 ... feature point correspondence unit, 22 ... three-dimensional coordinate calculation unit, 23 ... triangle network formation unit, 24 ... miscorresponding point determination unit, 25 ... three-dimensional shape measurement unit , 26 ... background removal unit, 27 ... feature point extraction unit, 28 ... corresponding point search unit, 29 ... side length determination unit, 30 ... area determination unit, 31 ... angle determination unit.

Claims (13)

An imaging unit for imaging the measurement object in an overlapping imaging area from a plurality of imaging positions;
A feature point association unit for correlating the position of the feature point of the measurement object in the overlapping image captured by the imaging unit;
A triangle network forming unit that connects the feature points associated by the feature point association unit with line segments to form a triangle network; and
A miscorresponding point determination unit that determines a miscorresponding point based on at least one of the side length, area, and angle of the triangular net formed by the triangular net forming unit;
Based on the position of the feature point excluding the point determined to be an erroneous correspondence point by the erroneous correspondence point determination unit and the plurality of imaging positions, the three-dimensional coordinates of the characteristic point of the measurement object or the three-dimensional of the measurement object A shape measuring apparatus comprising: a three-dimensional shape measuring unit for obtaining a shape. A calibration object with a reference point;
The imaging position / orientation measurement unit that obtains the imaging position and orientation of the imaging unit based on the position of a corresponding reference point in the overlapped image obtained by imaging the calibration subject. Shape measuring device.   The shape measuring apparatus according to claim 1, further comprising at least one of a horizontal angle measuring unit and a vertical angle measuring unit for measuring a shooting position of the shooting unit. A calibration object with a reference point in a predetermined positional relationship;
The imaging position / orientation measurement unit for obtaining an imaging position and orientation of the imaging unit based on a position of a corresponding reference point in an overlapping image obtained by imaging the calibration subject. Shape measuring device.   The miscorresponding point determination unit determines an erroneous corresponding point based on at least one of a side length, an area, and an angle of the triangular net when the triangular net forming unit forms a triangular net. The shape measuring apparatus according to claim 1.   The miscorresponding point determination unit, after deleting a side based on a side length of a triangular mesh, determines the isolated point as an erroneous corresponding point if the number of isolated points connected is equal to or less than a predetermined value. The shape measuring apparatus according to claim 1.   The miscorresponding point determination unit determines the apex as an improper corresponding point when the area of the triangle in the triangle network is a predetermined value or more and the apex of the triangle is the contour portion of the measurement object. The shape measuring apparatus according to claim 1.   The miscorresponding point determination unit determines that the vertex is an erroneous corresponding point when the angle of the triangle in the triangle network is equal to or smaller than a predetermined value and the vertex of the triangle constituting the angle is the contour portion of the measurement object. The shape measuring device according to claim 1.   The shape measuring apparatus according to claim 1, wherein the three-dimensional shape measuring unit measures a three-dimensional shape using the inside of the outline of the measurement object as a processing region.   The said three-dimensional shape measurement part determines the said process area | region by creating the convex hull line containing the outline of the said measurement object, and shaving inward from a convex hull line, It is characterized by the above-mentioned. Shape measuring device.   The shape measuring apparatus according to claim 5, wherein when the erroneous correspondence point determination unit determines that the erroneous correspondence point is the designation of the characteristic point corresponding to the erroneous correspondence point.   The three-dimensional shape measuring unit is configured to perform the process of removing the erroneous corresponding point performed when the initial value is obtained by the erroneous corresponding point determining unit when the measured value is subsequently obtained. The shape measuring apparatus according to claim 1. A feature point correspondence step for correlating the position of the feature point of the measurement object in the overlapping image taken from a plurality of photographing positions;
A triangle network forming step of connecting the feature points associated in the feature point association step with line segments to form a triangle network;
A miscorresponding point determining step of determining a miscorresponding point based on at least one of the side length, area, and angle of the triangular mesh formed in the triangular net forming step;
Based on the position of the feature point excluding the point determined as the erroneous correspondence point in the erroneous correspondence point determination step and the plurality of imaging positions, the three-dimensional coordinates of the characteristic point of the measurement object or the three-dimensional of the measurement object A program for executing a three-dimensional shape measurement step for obtaining a shape.

Images