Three-dimensional shape measuring apparatus, three-dimensional shape measuring method and program

Abstract

To prevent three-dimensional shapes from being measured with reduced accuracy in the alignment of multiple pieces of three-dimensional shape data.SOLUTION: An apparatus comprises a first specification unit 541 that specifies the primary absolute phase values corresponding to respective multiple pixels of a first imaging unit 3, based on the image of a first pattern in a first fringe imaging image and the image of a second pattern in a second fringe imaging image, a second specification unit 542 that specifies secondary absolute phase values corresponding to respective multiple pixels of a second imaging part 4 based on the image of the first pattern in the first stripe imaging image and the image of the second pattern in the second stripe imaging image, a conversion specification unit 55 that specifies a conversion value for converting the primary or secondary coordinates, and a shape specification unit 56 that converts the primary or secondary coordinates based on the conversion value and specifies the three-dimensional shape of a measurement target based on the coordinates after conversion.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a three-dimensional shape measuring device, a three-dimensional shape measuring method, and a program. [Background technology]

[0002] A method has been proposed for measuring the shape of a measurement object without contacting the measurement object by projecting a projection pattern, capturing an image of the measurement object onto which the projection pattern is projected, and analyzing the captured image (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-146298 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the three-dimensional shape measuring device described in Patent Document 1, when the measurement object is relatively large, it may not be possible to obtain an image of the entire measurement object with one imaging device, and therefore it may not be possible to measure the entire shape of the measurement object. In this case, it is possible to obtain multiple three-dimensional shape data by analyzing multiple images obtained by multiple imaging devices in the three-dimensional shape measuring device. The three-dimensional shape measuring device measures the entire shape of the measurement object by aligning these multiple three-dimensional shape data. However, there is a problem in that the accuracy of aligning the three-dimensional shape data decreases due to the influence of the passage of time or temperature change, and the measurement accuracy of the entire shape of the measurement object decreases due to this decrease in the accuracy of alignment. The decrease in accuracy of alignment is caused, for example, by the influence of the passage of time or temperature change of an instrument used for alignment.

[0005] The present invention has been made in consideration of these points, and aims to prevent alignment of multiple three-dimensional shape data created based on multiple captured images from being performed in a state where the alignment accuracy is reduced, resulting in the acquisition of a three-dimensional shape with reduced measurement accuracy. [Means for solving the problem]

[0006] A three-dimensional shape measuring device according to a first aspect of the present invention includes a projection unit that projects onto a measurement object a first fringe projection image having a first pattern whose luminance changes along a first direction and a second fringe projection image having a second pattern whose luminance changes along a second direction different from the first direction; a first imaging unit that generates a first fringe captured image obtained by capturing an image of the measurement object in a state in which the first fringe projection image is projected and a second fringe captured image obtained by capturing an image of the measurement object in a state in which the second fringe projection image is projected; a first determination unit that determines a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; the first fringe projection image and a second imaging unit that generates a second fringe captured image by capturing an image of the object to be measured with the second fringe projection image projected; a second identification unit that identifies a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit, based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; a conversion identification unit that identifies a conversion value for converting the primary coordinates or the secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value in three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are close to each other in the three-dimensional space; and a shape identification unit that converts the primary coordinates or the secondary coordinates based on the conversion value, and identifies a three-dimensional shape of the object to be measured based on the converted coordinates.

[0007] The transformation specification unit may specify the transformation values ​​including a translation amount by which the primary coordinates are translated to make the primary coordinates coincide with the secondary coordinates, and a rotation amount by which the primary coordinates are rotated to make the primary coordinates coincide with the secondary coordinates.

[0008] The present invention may further include a region dividing unit that divides a three-dimensional region including a plurality of primary coordinates corresponding to the plurality of primary absolute phase values ​​identified by the first identification unit into a plurality of primary partial regions, and divides a three-dimensional region including a plurality of secondary coordinates corresponding to the plurality of secondary absolute phase values ​​identified by the second identification unit into a plurality of secondary partial regions, wherein the transformation identification unit may identify, for each of the plurality of primary partial regions, the transformation value for transforming the primary coordinate or the secondary coordinate such that the primary partial region, the primary coordinate included in the primary partial region, and the secondary coordinate included in the secondary partial region corresponding to the same absolute phase value as the primary coordinate are approximated in the three-dimensional space.

[0009] The first identification unit may identify a plurality of the primary absolute phase values ​​in a plurality of measurements, the second identification unit may identify a plurality of the secondary absolute phase values ​​in the plurality of measurements, the transformation identification unit may identify the transformation values ​​for transforming the plurality of the primary coordinates or the plurality of the secondary coordinates such that the primary coordinates corresponding to each of the plurality of the primary absolute phase values ​​corresponding to the plurality of measurements in the three-dimensional space and the secondary coordinates corresponding to the secondary absolute phase value equal to the primary absolute phase value are close to each other in the three-dimensional space, and may identify statistics of the identified plurality of transformation values, and the shape identification unit may transform the primary coordinates or the secondary coordinates based on the statistics of the identified transformation values.

[0010] The transformation identification unit may identify a location in the three-dimensional space where the primary coordinate corresponding to the primary absolute phase value in the three-dimensional space and the secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value cannot be made to approach each other, based on the transformation value.

[0011] The first identification unit may extract primary features from the first stripe image generated by the first imaging unit and the second stripe image generated by the first imaging unit, and identify a primary reliability indicating the reliability of the primary absolute phase value based on the extracted primary features; the second identification unit may extract secondary features from the first stripe image generated by the second imaging unit and the second stripe image generated by the second imaging unit, and identify a secondary reliability indicating the reliability of the secondary absolute phase value based on the extracted secondary features; and the conversion identification unit may identify three-dimensional coordinates contained in the measured object by statistical processing based on the primary reliability and the secondary reliability.

[0012] The first identification unit may extract a primary feature from the first stripe image generated by the first imaging unit and the second stripe image generated by the first imaging unit, and identify a primary reliability indicating the reliability of the primary absolute phase value based on the extracted primary feature, the second identification unit extracts a secondary feature from the first stripe image generated by the second imaging unit and the second stripe image generated by the second imaging unit, and identify a secondary reliability indicating the reliability of the secondary absolute phase value based on the extracted secondary feature, and the conversion identification unit may identify the three-dimensional shape of the measurement object by selecting, for each primary coordinate, either the primary coordinate after alignment or the secondary coordinate transformed in the alignment so as to approach the primary coordinate, based on a comparison result between the primary reliability and the secondary reliability. The conversion identification unit may also identify a timing for next identifying the conversion value based on a result of comparing the identified conversion value with a previously identified conversion value.

[0013] The three-dimensional shape measuring device may further include a display control unit that specifies the conversion value at each predetermined time period and displays a transition of the conversion value previously specified by the conversion specifying unit. Also, a part of an imaging range of the first imaging unit and an imaging range of the second imaging unit may not overlap.

[0014] A three-dimensional shape measuring device according to a second aspect of the present invention includes a projection unit that projects onto a measurement object a first fringe projection image having a first pattern whose luminance changes along a first direction and a second fringe projection image having a second pattern whose luminance changes along a second direction, a first imaging unit that generates a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected, a first determination unit that determines a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit, and a first determination unit that determines a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on the first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected and the second fringe captured image. the second imaging unit generating a second fringe image obtained by imaging the object to be measured in a state in which an image is projected; a second identification unit identifying a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe image generated by the second imaging unit and an image of the second pattern in the second fringe image generated by the second imaging unit; a conversion identification unit identifying a conversion value for converting the primary coordinates or the secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value in three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value approach each other in the three-dimensional space; a determination unit determining that a positional deviation has occurred between the primary coordinates and the secondary coordinates when the conversion value is greater than a predetermined reference value; and an output unit outputting a determination result of the determination unit. In addition, after aligning the primary coordinates and the secondary coordinates, the coordinate difference for each corresponding point is calculated to identify the similarity between the primary coordinates and the secondary coordinates, and if the similarity is below a threshold, it may be determined that a malfunction has occurred in at least one of the projection unit, the first imaging unit, or the second imaging unit.

[0015] A three-dimensional shape measuring method according to a third aspect of the present invention includes the steps of: projecting a first fringe projection image having a first pattern whose luminance varies along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance varies along a second direction onto the measurement object; generating, by a first imaging unit, a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon; determining a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; the step of generating, by a second imaging unit, a first fringe image obtained by imaging an object and a second fringe image obtained by imaging the object to be measured with the second fringe projection image projected; the step of identifying a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe image generated by the second imaging unit and an image of the second pattern in the second fringe image generated by the second imaging unit; the step of identifying a conversion value for converting the primary coordinates or the secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value in three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are close to each other in the three-dimensional space; and the step of converting the primary coordinates or the secondary coordinates based on the conversion value, and identifying a three-dimensional shape of the object to be measured based on the converted coordinates.

[0016] A three-dimensional shape measuring method according to a fourth aspect of the present invention includes the steps of: projecting a first fringe projection image having a first pattern whose brightness varies along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose brightness varies along a second direction onto the measurement object; generating, by a first imaging unit, a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected; determining a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; the step of generating a second stripe captured image by a second imaging unit, capturing an image of the object to be measured with the second stripe projection image projected; the step of identifying a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first stripe captured image generated by the second imaging unit and an image of the second pattern in the second stripe captured image generated by the second imaging unit; the step of identifying a conversion value for converting the primary coordinates or the secondary coordinates so that a primary coordinate corresponding to the primary absolute phase value in three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value approach each other in the three-dimensional space; the step of determining that a positional shift has occurred between the primary coordinates and the secondary coordinates if the conversion value is greater than a predetermined reference value; and the step of outputting a determination result as to whether or not the positional shift has occurred.

[0017] A program according to a fifth aspect of the present invention includes a step of causing a computer to perform the steps of: projecting a first fringe projection image having a first pattern whose luminance changes along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance changes along a second direction onto the measurement object; generating, by a first imaging unit, a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon; specifying a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; the step of generating, by a second imaging unit, a first fringe captured image obtained by capturing an image of the object to be measured with the second fringe projected image projected thereon and a second fringe captured image obtained by capturing an image of the object to be measured with the second fringe projected image projected thereon; the step of identifying a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit, based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; the step of identifying a conversion value for converting the primary coordinates or the secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value in three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are close to each other in the three-dimensional space; and the step of converting the primary coordinates or the secondary coordinates based on the conversion value, and identifying a three-dimensional shape of the object to be measured based on the converted coordinates.

[0018] A sixth aspect of the present invention provides a program for causing a computer to perform the steps of: projecting a first fringe projection image having a first pattern whose luminance changes along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance changes along a second direction onto the measurement object; generating, by a first imaging unit, a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected; specifying a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; The system executes the following steps: generating a second stripe image by a second imaging unit, capturing an image of the object to be measured with a stripe projection image projected; identifying a secondary absolute phase value corresponding to each of the multiple pixels of the second imaging unit based on an image of the first pattern in the first stripe image generated by the second imaging unit and an image of the second pattern in the second stripe image generated by the second imaging unit; identifying a conversion value for converting the primary coordinates or the secondary coordinates so that a primary coordinate corresponding to the primary absolute phase value in three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are close to each other in the three-dimensional space; determining that a positional shift has occurred between the primary coordinates and the secondary coordinates if the conversion value is greater than a predetermined reference value; and outputting a determination result as to whether or not the positional shift has occurred. Effect of the Invention

[0019] According to the present invention, it is possible to suppress measurement of a three-dimensional shape in a state where the accuracy of alignment of a plurality of three-dimensional shape data created based on a plurality of captured images is reduced. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a diagram for explaining an overview of a three-dimensional shape measuring apparatus according to a first embodiment. [Diagram 2] 1 shows an example of a projected image projected onto a measurement object by a three-dimensional shape measuring device. [Diagram 3] 1 shows the configuration of a three-dimensional shape measuring device. [Figure 4] 3 shows examples of a first fringe projection image and a second fringe projection image. [Diagram 5] 13 shows an example of a first stripe projection image projected by a projection control unit. [Figure 6] 13 shows an example of a first stripe projection image projected by a projection control unit. [Figure 7] 13 shows another example of the arrangement of the first projection unit and the second projection unit. [Figure 8] 4 shows an example of a first stripe projection image that the projection control unit causes the first projection unit to project. [Figure 9] 13 shows another example of an arrangement of multiple projection units. [Figure 10] 2 shows another example of the configuration of the three-dimensional shape measuring device. [Figure 11] 2 shows another example of the configuration of the three-dimensional shape measuring device. [Figure 12] FIG. 13 is a diagram showing the relationship between a phase value and an absolute phase value. [Figure 13] An example of a method for determining a first and second absolute phase value will be described. [Figure 14] 4 is a flowchart showing a processing procedure for identifying a three-dimensional shape of a measurement object by the three-dimensional shape measuring device. [Figure 15] 15 is a flowchart showing the processing procedure of the conversion value identification process in FIG. 14. [Figure 16] 15 is a flowchart showing the processing procedure of the shape identification process in FIG. 14. [Figure 17] 4 shows the configuration of a three-dimensional shape measuring apparatus according to a second embodiment. [Figure 18] 13 shows the configuration of a three-dimensional shape measuring apparatus according to a third embodiment. [Figure 19]10 is a flowchart showing a processing procedure for determining whether or not a positional deviation occurs in a primary coordinate or a secondary coordinate in a three-dimensional shape measuring device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] <First embodiment> [Overview of the three-dimensional shape measuring device 100] Fig. 1 is a diagram for explaining an overview of a three-dimensional shape measuring device 100 according to a first embodiment. Fig. 2 shows an example of a projection image projected onto a measurement object by the three-dimensional shape measuring device 100. The three-dimensional shape measuring device 100 projects a projection image onto a measurement surface of the measurement object by two projection units, a first projection unit 1 and a second projection unit 2. The measurement object is an object whose three-dimensional shape is to be measured.

[0022] The three-dimensional shape measuring device 100 captures an image of a measurement object in a state where a projection image projected by the first projection unit 1 or the second projection unit 2 is projected, using two imaging units, a first imaging unit 3 and a second imaging unit 4. The three-dimensional shape measuring device 100 analyzes the captured images generated by the three-dimensional shape measuring device 100 to optically measure the three-dimensional shape of the measurement object.

[0023] The first projection unit 1 and the second projection unit 2 are projection devices having a light source such as a light emitting diode or a laser. The first projection unit 1 projects a first fringe projection image having a first pattern whose luminance changes along a first direction onto the measurement object. FIG. 2 shows an example of a first fringe projection image projected onto the measurement object by the first projection unit 1 or the second projection unit 2. The example of FIG. 2 shows a first fringe projection image including a binary fringe pattern. The second projection unit 2 projects a second fringe projection image having a second pattern whose luminance changes along a second direction onto the measurement object. The first direction and the second direction are, for example, orthogonal directions on the measurement object, but may be non-orthogonal directions. The projection image is used as a marker for identifying the three-dimensional coordinates of the measurement object.

[0024] 1 has a lens 31 and an image sensor 32. The first imaging unit 3 generates a one-way fringe image by imaging the measurement object with the first fringe projection image projected thereon. The first imaging unit 3 generates a one-way fringe image by imaging the measurement object with the second fringe projection image projected thereon.

[0025] The second imaging unit 4 has a lens 41 and an imaging element 42. The second imaging unit 4 generates a secondary first-fringe image by imaging the measurement object with the first fringe projection image projected thereon. The second imaging unit 4 generates a secondary second-fringe image by imaging the measurement object with the second fringe projection image projected thereon.

[0026] For example, when the first imaging unit 3 alone cannot image the entire object to be measured due to the object being large or having many projections and recesses, the second imaging unit 4 images the portion that the first imaging unit 3 cannot image. The first imaging unit 3 and the second imaging unit 4 generate the primary imaging image and the secondary imaging image such that a portion of the object to be measured that appears in the first-order stripe image and the second-order stripe image (hereinafter also referred to as the primary imaging image) is also overlapped in the secondary first-order stripe image and the secondary second-order stripe image (hereinafter also referred to as the secondary imaging image). At this time, a portion of the imaging range of the first imaging unit 3 and a portion of the imaging range of the second imaging unit 4 do not have to overlap.

[0027] The control unit 5 is realized by, for example, a computer. The control unit 5 measures the shape of the measurement object based on the multiple captured images generated by the first imaging unit 3 and the second imaging unit 4. The control unit 5 specifies three-dimensional coordinates by specifying the phase value of the pattern in each pixel of the projected image projected onto the measurement object. The phase value indicates the progress stage of the repeating period of the pattern whose luminance changes. The phase value indicates the same value for each period. The absolute phase value uniquely indicates the progress stage of the repeating period of the pattern. The pattern is, for example, a stripe pattern. The pattern may be a two-dimensional pattern such as a random pattern.

[0028] The control unit 5 aligns the three-dimensional shape data of the measurement object based on the primary captured image captured by the first imaging unit 3 with the three-dimensional shape data of the measurement object based on the secondary captured image captured by the second imaging unit 4. The following describes a procedure in which the control unit 5 aligns the three-dimensional shape data generated based on the primary captured image generated by the first imaging unit 3 with the three-dimensional shape data generated based on the secondary captured image generated by the second imaging unit 4. The control unit 5 generates a first-order first-stripe captured image and a second-order second-stripe captured image by capturing an image of the measurement object by the first imaging unit 3. The three-dimensional shape measuring device 100 generates a secondary first-stripe captured image and a secondary second-stripe captured image by capturing an image of the measurement object by the second imaging unit 4 ((1) in FIG. 1).

[0029] The control unit 5 determines first-order absolute phase values ​​in the first direction of the multiple pixels of the first imaging unit 3 based on the image of the first pattern captured in the primary first-stripe captured image. The control unit 5 determines first-order absolute phase values ​​in the second direction of the multiple pixels of the first imaging unit 3 based on the image of the second pattern captured in the primary second-stripe captured image ((2) in FIG. 1). The control unit 5 determines second-order absolute phase values ​​in the first direction of the multiple pixels of the second imaging unit 4 based on the image of the first pattern captured in the secondary first-stripe captured image. The control unit 5 determines second-order absolute phase values ​​in the second direction of the multiple pixels of the second imaging unit 4 based on the image of the second pattern captured in the secondary second-stripe captured image ((3) in FIG. 1).

[0030] The control unit 5 specifies three-dimensional coordinates (hereinafter also referred to as primary coordinates) corresponding to the primary absolute phase value in at least one of the specified first direction and second direction. The control unit 5 specifies three-dimensional coordinates (hereinafter also referred to as secondary coordinates) corresponding to the specified secondary absolute phase value in the first direction or the second direction. Here, when the primary absolute phase value and the secondary absolute phase value match, the primary coordinate corresponding to this primary absolute phase value and the secondary coordinate corresponding to this secondary absolute phase value also match. However, the primary coordinates and the secondary coordinates may not match due to measurement errors of the first imaging unit 3 or the second imaging unit 4 caused by the passage of time or temperature changes. For this reason, the control unit 5 specifies a conversion value for converting the primary coordinates so that the primary coordinates corresponding to the primary absolute phase value in the three-dimensional space and the secondary coordinates corresponding to the secondary absolute phase value equal to the primary absolute phase value approach each other in the three-dimensional space ((4) in FIG. 1).

[0031] Next, the three-dimensional shape measuring device 100 generates a primary captured image by re-imaging the measurement object with the first imaging unit 3, and identifies a plurality of primary absolute phase values ​​in the first direction and the second direction corresponding to this primary fringe captured image. Similarly, the three-dimensional shape measuring device 100 generates a secondary captured image by re-imaging the measurement object with the second imaging unit 4, and identifies a plurality of secondary absolute phase values ​​in the first direction and the second direction corresponding to this secondary captured image.

[0032] The three-dimensional shape measuring device 100 converts a plurality of primary coordinates corresponding to a new plurality of primary absolute phase values ​​based on the conversion value. The three-dimensional shape measuring device 100 identifies the three-dimensional shape of the entire measurement object by connecting the converted primary coordinates with a plurality of secondary coordinates corresponding to the new plurality of secondary absolute phase values ​​((5) in FIG. 1). In this way, the control unit 5 can suppress a decrease in the accuracy of alignment between the primary coordinates and the secondary coordinates due to the influence of the passage of time, temperature change, etc.

[0033] [Configuration of three-dimensional shape measuring device 100] 3 shows the configuration of three-dimensional shape measuring device 100. Three-dimensional shape measuring device 100 includes a first imaging unit 3, a second imaging unit 4, a control unit 5, a display unit 6, a storage unit 7, and a projection unit 10. The control unit 5 includes a projection control unit 51, an imaging control unit 52, an area division unit 53, a specification unit 54, a conversion specification unit 55, a shape specification unit 56, and a display control unit 57. The number of imaging units 3, 4 and projection units 1, 2 is not limited to two, and may be greater than two.

[0034] The display unit 6 is, for example, a display. The display unit 6 displays various information. The storage unit 7 includes a storage medium such as a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk, etc. The storage unit 7 stores a program executed by the control unit 5.

[0035] The projection unit 10 projects a first stripe projection image having a first pattern whose luminance changes along a first direction and a second stripe projection image having a second pattern whose luminance changes along a second direction onto a measurement object. The projection unit 10 includes a first projection unit 1 and a second projection unit 2.

[0036] The control unit 5 is, for example, a CPU (Central Processing Unit). The control unit 5 executes a program stored in the storage unit 7 to function as a projection control unit 51, an imaging control unit 52, an area dividing unit 53, a determination unit 54, a conversion determination unit 55, a shape determination unit 56, and a display control unit 57.

[0037] The projection control unit 51 controls the projection unit 10 to project the first fringe projection image or the second fringe projection image onto the measurement object. The projection control unit 51 causes the first projection unit 1 to project the first fringe projection image having a first pattern whose luminance changes along a first direction onto the measurement object. The projection control unit 51 causes the second projection unit 2 to project the second fringe projection image having a second pattern whose luminance changes along a second direction onto the measurement object. The second direction is, for example, a direction perpendicular to the first direction on the measurement object. The first and second directions may be in directions that are not perpendicular to each other.

[0038] 4(a) and 4(b) show examples of a first stripe projection image and a second stripe projection image. FIG. 4(a) shows an example of a first stripe projection image that the projection control unit 51 causes the first projection unit 1 to project. FIG. 4(b) shows an example of a second stripe projection image that the projection control unit 51 causes the second projection unit 2 to project. The first stripe projection image shown in FIG. 4(a) has a first pattern in which the luminance changes along the horizontal direction, which is the first direction. The second stripe projection image shown in FIG. 4(b) has a second pattern in which the luminance changes along the vertical direction, which is the second direction.

[0039] In the examples of FIG. 4(a) and FIG. 4(b), the second direction forms an angle of 90 degrees with the first direction. The projection control unit 51 may project the first fringe projection image and the second fringe projection image onto the measurement object only on the first projection unit 1 or only on the second projection unit 2. The projection control unit 51 may project the first fringe projection image and the second fringe projection image onto the measurement object on three or more projection units. As an example, when the projection control unit 51 projects the first fringe projection image and the second fringe projection image onto the measurement object on the first projection unit 1, the second projection unit 2, and the third projection unit (not shown), the projection control unit 51 may project the first fringe projection image onto the first projection unit 1, project another first fringe projection image onto the second projection unit 2, and project the second fringe projection image onto the third projection unit. In addition to projecting the first fringe projection image and the second fringe projection image onto the object to be measured by the first projection unit 1, the projection control unit 51 may also project the first fringe projection image and the second fringe projection image onto the object to be measured by the second projection unit 2.

[0040] 5(a) to 5(f) and 6(a) to 6(d) show examples of the first stripe projection image projected by the projection control unit 51. FIG. 5(a) to 5(f) show examples of binary stripe patterns. FIG. 6(a) to 6(d) show examples of gradation stripe patterns having a sine wave-like luminance distribution. In the gradation stripe patterns of FIG. 6(a) to 6(d), the shading changes sinusoidally from the white area to the black area along the width direction of the stripe. The gradation stripe patterns of FIG. 6(a) to 6(d) show the same luminance distribution except that the phases of the sine waves showing the luminance distribution are different by 90 degrees. The binary stripe pattern projected on the measurement object is analyzed by the determination unit 54 using a spatial coding method. The gradation stripe pattern projected on the measurement object having a sine wave-like luminance distribution is analyzed by the determination unit 54 using a phase shift method. The results of both analyses are combined and the absolute phase value is calculated by a determination unit 54, which will be described later. Any other stripe pattern can be used. For example, a pattern of multiple sine waves with different stripe periods may be used.

[0041] FIG. 7 shows another example of the arrangement of the first projection unit 1 and the second projection unit 2. In the example of FIG. 7, the first imaging unit 3 and the first projection unit 1 are accommodated in the same frame 60a. The second projection unit 2 and the second imaging unit 4 are accommodated in the same frame 60b. W in FIG. 7 indicates a measurement object. The dashed lines in FIG. 7 indicate the optical axis of the first imaging unit 3 or the second imaging unit 4 and the outermost point of the imaging range. In addition, in the three-dimensional shape measuring device 100, the number of imaging units or projection units accommodated in one frame 60a or 60b may be further increased. A shape specification unit 56 (described later) may specify a plurality of three-dimensional shapes corresponding to a plurality of captured images captured by a plurality of imaging units accommodated in one frame, and align the specified three-dimensional shapes.

[0042] FIG. 8(a) shows an example of a primary projection image that the projection control unit 51 causes the first projection unit 1 to project. FIG. 8(b) shows an example of a secondary projection image that the projection control unit 51 causes the second projection unit 2 to project. In the example of FIG. 8(b), the projection control unit 51 projects the same image as the first stripe projection image shown in FIG. 8(a) from the second projection unit 2, which has a different orientation from the first projection unit 1, onto the measurement object, so that the orientation of the stripes appears different from that of the first stripe projection image shown in FIG. 8(a) when projected onto the measurement object. In addition, the projection unit 10 is not limited to the example including the first projection unit 1 and the second projection unit 2, and may include more projection units. In addition, the image capture unit, the projection unit, and the frame that houses the image capture unit or the projection unit may be configured so that their positions can be changed.

[0043] Fig. 9 shows another example of the arrangement of a plurality of projection units. In the example of Fig. 9, the three-dimensional shape measuring device 100 includes a first imaging unit 3 and a first projection unit 1 housed in a frame 60a, a second projection unit 2 and a second imaging unit 4 housed in a frame 60b, and an auxiliary projection unit 70. By increasing the number of projection units, the three-dimensional shape measuring device 100 can prevent the occurrence of shadow areas on the measurement object where the projected image is not projected, and the inability to ensure sufficient parallax between the imaging unit and the projection unit.

[0044] The projection unit 10 is not limited to the example including the first projection unit 1 and the second projection unit 2, and may include either the first projection unit 1 or the second projection unit 2. FIG. 10 shows a configuration example of a three-dimensional shape measuring device 100 in which the projection unit 10 includes only the first projection unit 1. The first projection unit 1 projects a first stripe projection image having a first pattern whose luminance changes along a first direction onto the measurement object W. The first projection unit 1 also projects a second stripe projection image having a second pattern whose luminance changes along a second direction onto the measurement object W. The projection control unit 51 may control the projection unit 10 to project a projection image including a stripe pattern whose extension direction differs in each of a plurality of measurements onto the measurement object W. In the three-dimensional shape measuring device 100, the first projection unit 1, the second projection unit 2, and the first imaging unit 3 may be accommodated in one frame.

[0045] The imaging control unit 52 generates an image of the measurement object captured by the first imaging unit 3 or the second imaging unit 4. The imaging control unit 52 generates a first-order fringe captured image of the measurement object with the first fringe projection image projected thereon by the first imaging unit 3. The imaging control unit 52 generates a secondary first-order fringe captured image of the measurement object with the first fringe projection image projected thereon by the second imaging unit 4. The imaging control unit 52 generates a first-order two-order fringe captured image of the measurement object with the second fringe projection image projected thereon by the first imaging unit 3. The imaging control unit 52 generates a secondary second-order fringe captured image of the measurement object with the second fringe projection image projected thereon by the second imaging unit 4.

[0046] The imaging control unit 52 may generate a plurality of primary captured images in a plurality of measurements by the first imaging unit 3. The imaging control unit 52 may generate a plurality of secondary captured images in a plurality of measurements by the second imaging unit 4. The imaging control unit 52 outputs the generated first and second stripe captured images to the region dividing unit 53 and the identifying unit 54.

[0047] The imaging control unit 52 may generate an image by using an additional imaging unit in addition to the first imaging unit 3 and the second imaging unit 4. FIG. 11 shows a configuration example of a three-dimensional shape measuring device 100 having an additional imaging unit. The three-dimensional shape measuring device 100 includes a third imaging unit 81 and a fourth imaging unit 82 in addition to the first imaging unit 3 and the second imaging unit 4. The imaging control unit 52 generates a first-order fringe image by imaging the measurement object W with the first fringe projection image projected thereon by the first imaging unit 3. The imaging control unit 52 generates a second-order first fringe image by imaging the measurement object W with the first fringe projection image projected thereon by the second imaging unit 4. The imaging control unit 52 generates a third-order fringe image by imaging the measurement object W with the first fringe projection image projected thereon by the third imaging unit 81. The imaging control unit 52 generates a fourth-order fringe image by imaging the measurement object W with the first fringe projection image projected thereon by the fourth imaging unit 82.

[0048] Furthermore, three-dimensional shape measuring device 100 may include a first frame, a second frame, a third frame, and a fourth frame, instead of first imaging section 3, second imaging section 4, third imaging section 81, and fourth imaging section 82. Each of the first frame to fourth frame may include one or more imaging sections and one or more projection sections.

[0049] The imaging control unit 52 generates a first-order two-stripe image by imaging the measurement object W with the second stripe projection image projected thereon by the first imaging unit 3. The imaging control unit 52 generates a second-order two-stripe image by imaging the measurement object W with the second stripe projection image projected thereon by the second imaging unit 4. The imaging control unit 52 generates a third-order two-stripe image by imaging the measurement object W with the second stripe projection image projected thereon by the third imaging unit 81. The imaging control unit 52 generates a fourth-order two-stripe image by imaging the measurement object W with the second stripe projection image projected thereon by the fourth imaging unit 82. In this way, the imaging control unit 52 can increase the number of images used to identify the three-dimensional shape of the measurement object, thereby improving the measurement accuracy of triangulation.

[0050] The region dividing unit 53 divides a three-dimensional region including a plurality of three-dimensional coordinates of the measurement object into a plurality of partial regions. First, the region dividing unit 53 identifies a plurality of primary coordinates corresponding to the plurality of primary absolute phase values ​​identified by the first identification unit 541. The region dividing unit 53 identifies a three-dimensional region including the identified plurality of primary coordinates, and divides this three-dimensional region into a plurality of primary partial regions.

[0051] Similarly, the region dividing unit 53 divides the three-dimensional region including the multiple secondary coordinates corresponding to the multiple secondary absolute phase values ​​identified by the second identifying unit 542 into multiple secondary partial regions. At this time, the region dividing unit 53 matches the three-dimensional region including the multiple primary coordinates before division with the three-dimensional region including the multiple secondary coordinates before division. For example, the region dividing unit 53 divides each three-dimensional region so that the boundary when dividing the three-dimensional region including the multiple primary coordinates matches the boundary when dividing the three-dimensional region including the multiple secondary coordinates. The boundaries of the primary side and the secondary side do not necessarily need to match, and it is sufficient that the regions on the primary coordinate side and the secondary coordinate side partially overlap.

[0052] The region dividing unit 53 may also divide a three-dimensional region designated by a user. The three-dimensional region may have any shape, such as a circular region or a rectangular region. The region dividing unit 53 may divide only the three-dimensional region in which the user is interested, and may perform alignment between the primary coordinates included in the divided primary partial region and the corresponding secondary coordinates. The region dividing unit 53 is not limited to an example of dividing a three-dimensional region including primary coordinates or secondary coordinates. For example, the region dividing unit 53 may form a plurality of primary partial regions by dividing at least a part of the primary captured image. The region dividing unit 53 may form a plurality of secondary partial regions by dividing at least a part of the secondary captured image.

[0053] Similarly, the region dividing unit 53 divides the image of the measurement object captured in the secondary first stripe captured image into images of a plurality of secondary first stripe partial regions. The region dividing unit 53 divides the image of the measurement object captured in the secondary second stripe captured image into images of a plurality of secondary second stripe partial regions along the same boundaries as the boundaries of the plurality of regions generated by dividing the secondary first stripe captured image. The region dividing unit 53 outputs information indicating the plurality of primary partial regions and the plurality of secondary partial regions after division to the identification unit 54.

[0054] [Determine absolute phase value] The determination unit 54 determines the absolute phase value of the pattern of the first fringe projection image or the second fringe projection image captured in each pixel of the primary captured image or the secondary captured image. FIG. 12 is a diagram showing the relationship between the phase value and the absolute phase value. The vertical axis of FIG. 12 indicates the phase value or the absolute phase value. The horizontal axis of FIG. 12 indicates the position of the pixel of the projected image. The solid line of FIG. 12 indicates the phase value, and the dashed line of FIG. 12 indicates the absolute phase value. The phase value indicates the progress stage of the repeating period of the pattern whose luminance changes. The phase value indicates the same value for each period. The absolute phase value is a value that uniquely determines the progress stage of the repeating period of the pattern without repeating the same value in different periods.

[0055] The determination unit 54 includes a first determination unit 541 and a second determination unit 542. The first determination unit 541 determines a first direction absolute phase value corresponding to each of the multiple pixels of the first imaging unit 3 based on an image of a first pattern in the single-sided stripe captured image. The first determination unit 541 determines a second direction absolute phase value corresponding to each of the multiple pixels of the first imaging unit 3 based on an image of a second pattern in the single-sided stripe captured image.

[0056] For example, when the projection control unit 51 projects the first fringe projection images of FIGS. 5(a) to 5(f) and 6(a) to 6(f) onto the measurement target W, the first determination unit 541 determines the absolute phase value by determining the luminance of the pixels of each of the projected first fringe projection images. AP,S1 (i s1 ,j s1 ) can be expressed, for example, by the following formula (1):

number

[0057] Similarly, the second determination unit 542 determines the secondary absolute phase value in the first direction corresponding to each of the multiple pixels of the second imaging unit 4 based on the image of the first pattern in the secondary first fringe captured image. The second determination unit 542 determines the secondary absolute phase value in the second direction corresponding to each of the multiple pixels of the second imaging unit 4 based on the image of the second pattern in the secondary second fringe captured image. The secondary absolute phase value I AP,S2 (i s2 ,j s2 ) can be expressed, for example, by the following formula (2):

number

[0058] When the area dividing unit 53 divides the image of the measurement object captured in the single-sided stripe captured image into images of multiple single-sided stripe partial areas, the first determining unit 541 determines multiple first-direction primary absolute phase values ​​corresponding to each of multiple pixels in the image of the single-sided stripe partial area.When the area dividing unit 53 divides the image of the measurement object captured in the double-sided stripe captured image into multiple double-sided stripe partial areas, the first determining unit 541 determines multiple second-direction primary absolute phase values ​​corresponding to each of multiple pixels in the double-sided stripe partial area.

[0059] When the area dividing unit 53 divides the image of the measurement object captured in the secondary first fringe captured image into images of multiple secondary first fringe partial areas, the second identifying unit 542 identifies multiple secondary absolute phase values ​​in the first direction corresponding to each of multiple pixels in the image of the secondary first fringe partial area.When the area dividing unit 53 divides the image of the measurement object captured in the secondary second fringe captured image into multiple secondary second fringe partial areas, the second identifying unit 542 identifies multiple secondary absolute phase values ​​in the second direction corresponding to each of multiple pixels in the secondary second fringe partial area.

[0060] When the imaging control unit 52 generates a plurality of single-strand captured images in a plurality of measurements, the first determination unit 541 may determine a plurality of first-direction primary absolute phase values ​​corresponding to the plurality of first-strand captured images. The first determination unit 541 may determine a plurality of second-direction primary absolute phase values ​​in a plurality of measurements. Similarly, the second determination unit 542 may determine a plurality of first-direction primary absolute phase values ​​in a plurality of measurements. The second determination unit 542 may determine a plurality of second-direction secondary absolute phase values ​​in a plurality of measurements.

[0061] [Identifying the reliability] The first determination unit 541 extracts a primary feature amount in the first direction from the first-stripe captured image. The first determination unit 541 determines a primary reliability in the first direction indicating the reliability of the primary absolute phase value in the first direction based on the extracted primary feature amount in the first direction. For example, the primary feature amount may be a luminance value of a pixel in the first-stripe captured image.

[0062] More specifically, the first determination unit 541 determines, as a primary feature, a difference or ratio between the luminance of any pixel in the primary captured image in a state where light is projected onto the entire measurement object and the luminance of the same pixel in an image captured in a state where light is not projected onto the measurement object. The first determination unit 541 determines a primary reliability of a pixel included in the primary captured image based on the value of the primary feature. As an example, the first determination unit 541 assigns a higher primary reliability to a pixel as the value of the primary feature becomes larger.

[0063] For example, when the identified difference is equal to or greater than a threshold, the first determination unit 541 assigns a relatively high primary reliability to this pixel. On the other hand, when the identified difference is less than the threshold, the first determination unit 541 assigns a relatively low primary reliability to this pixel. The threshold can be determined, for example, by determining the relationship between reliability and measurement error in advance.

[0064] The first determination unit 541 may determine a luminance value or the like extracted from a plurality of binary stripe patterns as a primary feature. For example, the first determination unit 541 may assign a relatively high primary reliability to a plurality of pixels in a primary partial region when a difference value between a maximum and a minimum of luminance values ​​of a plurality of binary stripe patterns for the same pixel is equal to or greater than a predetermined amount. The first determination unit 541 may assign a relatively low primary reliability to a plurality of pixels in a primary partial region when a difference value between a maximum and a minimum of luminance values ​​of a plurality of binary stripe patterns for the same pixel is less than a predetermined amount.

[0065] Furthermore, when the projection control unit 51 projects a grayscale stripe pattern having a sinusoidal brightness distribution onto the measurement target W, the first determination unit 541 may determine the amplitude of the sine wave, the offset of the sine wave, the contrast of the sine wave, the waveform distortion of the sine wave, etc., of each pixel as the primary feature amount. The offset indicates the average brightness value in the grayscale stripe pattern having a sinusoidal brightness distribution. This contrast is expressed by the following formula (3): (Contrast) = (Single amplitude of sine wave) / (Offset of sine wave)...(3) The waveform distortion of a sine wave represents the amount of distortion in which the change in phase corresponding to a pixel position is not uniform in the time direction when the phase of the stripe pattern corresponding to the pixel position is identified in a different stripe pattern image projected onto the same pixel position in a sine wave stripe pattern.

[0066] For example, when a plurality of sine wave gradation stripe patterns with sine wave phases differing by 90 degrees are projected onto a measurement target, the phases corresponding to the luminance projected onto the same pixel should change by 90 degrees, but due to the influence of distortion, the phases corresponding to the observed values ​​of the luminance of this pixel may not change by 90 degrees. The first identification unit 541, for example, identifies the deviation between the value obtained when the observed value of this pixel is applied to a sine wave and the observed value of this pixel, and identifies the waveform distortion of the sine wave gradation stripe pattern as a primary feature based on the identified deviation.

[0067] The values ​​of these primary feature quantities can be treated as the primary reliability of the pixel almost as it is. The first determination unit 541 may determine the primary reliability based on the value of the primary feature quantity, or may determine the primary reliability based on the values ​​of a plurality of primary feature quantities. For example, the first determination unit 541 may assign a relatively high primary reliability to the pixel when the amplitude or offset of the luminance of the identified pixel is within a predetermined range. On the other hand, the first determination unit 541 may assign a relatively low primary reliability to the pixel when the amplitude or offset of the luminance of the identified pixel is greater than the maximum value of the predetermined range and when the amplitude or offset of the luminance of the identified pixel is smaller than the minimum value of the predetermined range.

[0068] Similarly, the first determination unit 541 extracts a primary feature amount in the second direction from the first two-stripe captured image. The first determination unit 541 determines a primary reliability in the second direction indicating the reliability of the primary absolute phase value in the second direction based on the extracted primary feature amount in the second direction. The second determination unit 542 extracts a secondary feature amount in the first direction from the secondary first-stripe captured image. The second determination unit 542 determines a secondary reliability in the first direction indicating the reliability of the secondary absolute phase value in the first direction based on the extracted secondary feature amount in the first direction. The second determination unit 542 extracts a secondary feature amount in the second direction from the secondary second-stripe captured image. The second determination unit 542 determines a secondary reliability in the second direction indicating the reliability of the secondary absolute phase value in the second direction based on the extracted secondary feature amount in the second direction.

[0069] The first determination unit 541 may determine the primary reliability of each pixel based on the primary feature amount in either the first direction or the second direction, or may determine the primary reliability of each pixel based on the primary feature amount in both the first direction and the second direction.

[0070] Similarly, the second determination unit 542 may determine the secondary reliability of each pixel based on the secondary feature amount in either the first direction or the second direction, or may determine the secondary reliability of each pixel based on the feature amounts in both the first direction and the second direction. The first determination unit 541 and the second determination unit 542 may determine the reliability based on various feature amounts that can be determined by known techniques from the captured image, the phase value of the stripe pattern, or three-dimensional coordinates, etc.

[0071] [Specify conversion value] The conversion specifying unit 55 specifies a conversion value for converting a primary coordinate, which is a three-dimensional coordinate corresponding to the primary absolute phase values ​​in the first direction and the second direction specified by the first specifying unit 541, or a secondary coordinate, which is a three-dimensional coordinate corresponding to the secondary absolute phase values ​​in the first direction and the second direction specified by the second specifying unit 542. FIG. 13 shows an example of a method for specifying a primary absolute phase value and a secondary absolute phase value. The measurement object is shown by a dashed oval in FIG. 13. A first pattern of stripes φ1 included in a first projection image projected onto the measurement object and a second pattern of stripes φ2 included in a second projection image projected onto the measurement object are shown.

[0072] The first imaging unit 3 and the second imaging unit 4 generate a primary captured image and a secondary captured image of the measurement object. In the example of Fig. 13, the first identifying unit 541 identifies a primary absolute phase value in the first direction corresponding to the stripe φ1 in the primary captured image of the measurement object on the left side. The first identifying unit 541 identifies a primary absolute phase value in the second direction corresponding to the stripe φ2 in the primary captured image.

[0073] The second determination unit 542 determines a secondary absolute phase value in the first direction corresponding to the stripe φ1 in the right secondary captured image of the measurement object. The second determination unit 542 determines a secondary absolute phase value in the second direction corresponding to φ2 in the secondary captured image. Here, the intersection a between the stripes φ1 and φ2 in the primary captured image corresponds to the same three-dimensional coordinates on the measurement object as the intersection b between the stripes φ1 and φ2 in the secondary captured image. Therefore, the transformation determination unit 55 determines a pair of primary and secondary coordinates corresponding to the same absolute phase value, and determines a transformation value for aligning the primary and secondary coordinates in the determined pair.

[0074] The conversion specifying unit 55 may output an error when the number of pairs of the specified primary coordinates and secondary coordinates is less than a reference value due to reasons such as the measurement target being small, etc. The reference value is determined according to, for example, the maximum measurement error allowable in measuring a three-dimensional shape.

[0075] For example, the conversion specifying unit 55 may output an error message to the display unit 6 to notify the user that it is necessary to place another member within the range in which the first and second fringe projection images are projected around the measurement object. When the user places another member within the range in which the first and second fringe projection images are projected, the first and second fringe projection images are also projected onto this member, so that it becomes possible to make the number of pairs of primary coordinates and secondary coordinates corresponding to the same absolute phase value equal to or greater than a reference value.

[0076] The operation of the conversion specification unit 55 will be described in detail below. First, the conversion specification unit 55 specifies the plurality of first absolute phase values ​​I AP,S1 (i s1 , j s1 ) and the plurality of secondary absolute phase values ​​I AP,S2 (i s2 , j s2 ) and the primary absolute phase value I AP,S1 (i s1 , j s1 ) and the secondary absolute phase value I AP,S2 (i s2 , js2 The transformation specification unit 55 specifies pairs in which the first-order absolute phase value I AP,S1 (i s1 , j s1 ) on the measurement object W etc. s1 (i s1 ,j s1 ) and the secondary absolute phase value I AP,S2 (i s2 , j s2 ) on the measurement object W etc. s2 (i s2 ,j s2 ) are approximated in three-dimensional space.

[0077] In the examples herein, the transformation specification unit 55 specifies a transformation value for transforming the primary coordinates or the secondary coordinates so that the primary coordinates and the secondary coordinates are closer to each other in three-dimensional space, the transformation value including a translation amount by which the primary coordinates are translated to match the secondary coordinates, and a rotation amount by which the primary coordinates are rotated to match the secondary coordinates.

[0078] When the first determination unit 541 has determined a plurality of primary absolute phase values ​​corresponding to the respective pixels of the plurality of primary partial regions, the conversion determination unit 55 determines a plurality of primary coordinates corresponding to the plurality of primary absolute phase values ​​in the three-dimensional space. Similarly, when the second determination unit 542 has determined a plurality of secondary absolute phase values ​​corresponding to the respective pixels of the plurality of secondary partial regions, the conversion determination unit 55 determines a plurality of secondary coordinates corresponding to the plurality of secondary absolute phase values ​​in the three-dimensional space. The conversion determination unit 55 determines a plurality of pairs in which the primary absolute phase value and the secondary absolute phase value are equal.

[0079] The transformation specification unit 55 may specify, for each of the specified plurality of pairs, transformation values ​​for transforming the plurality of primary coordinates or the plurality of secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value of any one of the pairs and a secondary coordinate corresponding to the secondary absolute phase value of the same pair approach each other in the three-dimensional space.

[0080] The transformation specifying unit 55 may specify, for each of the plurality of primary partial regions or the plurality of secondary partial regions, a plurality of transformation values ​​for transforming a plurality of primary coordinates corresponding to the primary partial region or a plurality of secondary coordinates corresponding to the secondary partial region. The transformation specifying unit 55 specifies a transformation value for each of the primary partial regions divided by the region dividing unit 53.

[0081] At this time, the conversion specification unit 55 specifies a conversion value for converting the primary coordinates or the secondary coordinates for each of the multiple primary partial regions such that the primary coordinates included in the primary partial region in the three-dimensional space and the secondary coordinates corresponding to the same absolute phase value as the primary coordinates are close to each other in the three-dimensional space. The conversion specification unit 55 specifies a conversion value for each primary partial region, thereby enabling alignment between smaller regions. Therefore, the conversion specification unit 55 can improve the accuracy of alignment between the primary coordinates and the secondary coordinates.

[0082] If the conversion specifying unit 55 performs the alignment for each primary partial region using only the primary partial region required for the measurement specified in advance, the measurement can be performed more efficiently. Moreover, the conversion specifying unit 55 is not limited to the example of dividing a three-dimensional region. For example, the conversion specifying unit 55 may divide the primary captured image or the secondary captured image to generate partial images and specify a conversion value for each of the partial images. In this way, the conversion specifying unit 55 specifies a plurality of conversion values ​​corresponding to a plurality of primary partial regions or secondary partial regions, so that the primary coordinates or secondary coordinates can be aligned with high accuracy even if non-uniform measurement errors occur in the primary coordinates or secondary coordinates due to the passage of time or temperature change.

[0083] The conversion specifying unit 55 may specify a primary feature amount for each primary partial region, and specify a primary reliability based on the specified primary feature amount. The conversion specifying unit 55 may specify a secondary feature amount for each secondary partial region, and specify a secondary reliability based on the specified secondary feature amount. The conversion specifying unit 55 may prevent a primary partial region whose specified primary reliability is equal to or less than a threshold from being used in calculating the conversion value. The conversion specifying unit 55 may exclude a primary partial region whose specified primary reliability is equal to or less than a threshold from the three-dimensional shape of the measurement object after alignment.

[0084] When the first specifying unit 541 and the second specifying unit 542 specify a plurality of first absolute phase values ​​and a plurality of second absolute phase values ​​in a plurality of measurements, the conversion specifying unit 55 specifies a plurality of pairs in which the first absolute phase value and the second absolute phase value are equal in each measurement. The conversion specifying unit 55 specifies a conversion value for each of the pairs specified in each measurement such that a first coordinate corresponding to each of the first absolute phase values ​​of the pair and a second coordinate corresponding to the second absolute phase value of the same pair are close to each other in three-dimensional space. The conversion specifying unit 55 specifies a plurality of conversion values ​​for each of the plurality of measurements. The conversion specifying unit 55 specifies statistics of the plurality of conversion values. The statistics is, for example, an average value of the plurality of conversion values ​​corresponding to the plurality of measurements. The statistics may be a median value of the plurality of conversion values ​​corresponding to the plurality of measurements.

[0085] In addition, when the transformation determination unit 55 determines the statistics of multiple transformation values ​​corresponding to multiple measurements, it may project the same stripe image repeatedly using the same projection unit 1 or 2, but it may also determine the statistics of multiple transformation values ​​corresponding to multiple measurements obtained with a different combination, for example, by projecting in two directions using projection unit 1 and in two directions using projection unit 1 or 2.

[0086] When the primary absolute phase value or the secondary absolute phase value contains noise, the conversion specifying unit 55 may not be able to accurately align the primary coordinates or the secondary coordinates so as to bring the primary coordinates corresponding to the primary absolute phase value and the secondary coordinates corresponding to the secondary absolute phase value closer to each other. For this reason, the conversion specifying unit 55 may specify, based on the conversion value, a location in the three-dimensional space where the primary coordinates corresponding to the primary absolute phase value in the three-dimensional space and the secondary coordinates corresponding to the secondary absolute phase value equal to the primary absolute phase value cannot be brought closer to each other.

[0087] For example, when a portion that does not match the secondary coordinates remains in the primary coordinates converted using the identified conversion value, the conversion specifying unit 55 specifies this portion. When there are a first predetermined number or more of portions where the primary coordinates and the secondary coordinates cannot be made close to each other, the conversion specifying unit 55 may determine that alignment is impossible. The first predetermined number is determined according to, for example, the size of the measurement object. When there are a second predetermined number or more of portions where the primary coordinates and the secondary coordinates cannot be made close to each other, the conversion specifying unit 55 may specify that there is an abnormality in the first imaging unit 3, the second imaging unit 4, or the projection unit. The second predetermined number is, for example, a number larger than the first predetermined number.

[0088] The conversion specification unit 55 converts the primary coordinates or secondary coordinates using the specified conversion value, and then specifies the three-dimensional coordinates included in the measurement target by statistical processing based on the primary reliability specified by the first specification unit 541 and the secondary reliability specified by the second specification unit 542. The statistical processing is, for example, calculating an average value. More specifically, the conversion specification unit 55 specifies a primary weight of the primary coordinate value based on the primary reliability of at least one of the first direction or the second direction specified by the first specification unit 541. For example, the conversion specification unit 55 sets a larger value for the primary weight of the primary coordinate value as the primary reliability specified by the first specification unit 541 is higher. The conversion specification unit 55 specifies a secondary weight of the secondary coordinate value based on the secondary reliability of at least one of the first direction or the second direction.

[0089] The transformation determination unit 55 determines the average three-dimensional coordinate by a weighted average using the first weight and the second weight. The transformation determination unit 55 determines the average three-dimensional coordinate by a weighted average of multiplying the first weight by the first coordinate corresponding to the first absolute phase value and multiplying the second weight by the second coordinate corresponding to the second absolute phase value.

[0090] The conversion specifying unit 55 may evaluate the quality of the alignment based on the primary reliability and the secondary reliability. For example, the conversion specifying unit 55 may determine that alignment is possible when the primary reliability is equal to or greater than a threshold and the secondary reliability is equal to or greater than a threshold. On the other hand, the conversion specifying unit 55 may determine that alignment is not possible when the primary reliability is less than the threshold or when the secondary reliability is less than a threshold.

[0091] The conversion specifying unit 55 compares the primary reliability specified by the first specifying unit 541 with the secondary reliability specified by the second specifying unit 542. At this time, the conversion specifying unit 55 compares the primary reliability corresponding to the primary coordinates after the alignment with the secondary reliability corresponding to the secondary coordinates transformed in the alignment so as to approach the primary coordinates.

[0092] Based on the comparison result, the conversion specification unit 55 selects, for each primary coordinate, either the primary coordinate after alignment or the secondary coordinate transformed in the alignment so as to approach the primary coordinate. For example, the conversion specification unit 55 selects the primary coordinate or the secondary coordinate transformed to approach the primary coordinate, whichever has a higher corresponding reliability. The conversion specification unit 55 may specify the three-dimensional shape of the measurement object by integrating the selected coordinates.

[0093] The conversion specifying unit 55 may specify the timing for specifying the conversion value next by predicting the degree of deterioration of the measurement accuracy of the three-dimensional shape due to factors such as the passage of time or temperature change. For example, the conversion specifying unit 55 may specify a difference, ratio, or the like as a comparison between the specified conversion value and a previously specified conversion value, and specify the timing for specifying the conversion value next based on the specified difference. More specifically, the conversion specifying unit 55 predicts the timing for the translation amount included in the conversion value to become greater than a predetermined translation threshold based on the specified difference and the period since the previously specified conversion value. The larger the specified difference, the shorter the period from the previous specification of the conversion value to the next specification of the conversion value. In this way, the conversion specifying unit 55 can accurately set the timing for re-specifying the conversion value depending on whether the environment is one in which errors due to the passage of time or temperature change are likely to occur.

[0094] The conversion specifying unit 55 may predict the timing when the rotation amount included in the conversion value becomes greater than a predetermined rotation threshold based on the specified difference and the period since the conversion value was previously specified. The conversion specifying unit 55 specifies the predicted timing as the timing for specifying the conversion value next.

[0095] The conversion specifying unit 55 may specify the conversion value when the ambient temperature has changed by a predetermined amount or more, based on the ambient temperature of the three-dimensional shape measuring device 100 when the conversion value was previously specified. The predetermined amount is, for example, several degrees. The conversion specifying unit 55 may not specify the conversion value when the ambient temperature of the three-dimensional shape measuring device 100 has not changed by a predetermined amount or more. The conversion specifying unit 55 may specify the conversion value each time a predetermined period has elapsed since the conversion value was previously specified. The predetermined period is, for example, several hours or several tens of days. The conversion specifying unit 55 may specify the conversion value when the arrangement of the first imaging unit 3, the second imaging unit 4, the first projection unit 1, or the second projection unit 2 is changed.

[0096] The conversion specifying section 55 does not have to specify pairs in which the first absolute phase value and the second absolute phase value are equal for all pixels of the first imaging section 3 and all pixels of the second imaging section 4. In other words, the conversion specifying section 55 may specify pairs in which the first absolute phase value and the second absolute phase value are equal for some pixels of the first imaging section 3 and some pixels of the second imaging section 4.

[0097] For example, the conversion specification unit 55 may thin out some of the pixels of the first imaging unit 3 and the second imaging unit 4, and then specify pairs of the thinned out pixels of the first imaging unit 3 and the thinned out pixels of the second imaging unit 4 in which the first absolute phase value and the second absolute phase value are equal. The conversion specification unit 55 outputs information indicating the specified conversion value to the shape specification unit 56. By operating the conversion specification unit 55 in this manner, it is possible to reduce the time required to specify the conversion value. The conversion specification unit 55 may thin out only the pixels of either the first imaging unit 3 or the second imaging unit 4.

[0098] The conversion specification unit 55 may evaluate the accuracy of alignment between the primary coordinates and the secondary coordinates based on the size of an area of ​​the measurement object that is commonly shown in both the primary captured image and the secondary captured image. For example, the conversion specification unit 55 may determine that the primary coordinates and the secondary coordinates can be aligned when the area of ​​the area of ​​the measurement object that is commonly shown in both the primary captured image and the secondary captured image is equal to or larger than a threshold. The threshold is determined according to the size of the measurement object, for example.

[0099] The conversion specification unit 55 may determine that the primary coordinates and the secondary coordinates cannot be aligned when the area of ​​a region of the measurement object that appears in both the primary captured image and the secondary captured image is less than a threshold value. The conversion specification unit 55 may display the region that appears in both the primary captured image and the secondary captured image on the display unit 6. The administrator can appropriately position a frame or the like that houses the imaging unit or the projection unit by referring to the display unit 6 that displays the region that appears in both the primary captured image and the secondary captured image.

[0100] When the three-dimensional shape measuring device 100 includes three or more imaging units, the conversion specifying unit 55 may specify, for each combination of the imaging units, whether it is possible to align the multiple three-dimensional coordinates specified by the shape specifying unit 56 from images captured by two of the three or more imaging units. The conversion specifying unit 55 may specify a combination of two imaging units that is determined to be able to align the positions.

[0101] When it is possible for the conversion determination unit 55 to align the three-dimensional coordinates determined by the shape determination unit 56 from an image captured by one imaging unit with the three-dimensional coordinates determined by the shape determination unit 56 from images captured by the other multiple imaging units, the conversion determination unit 55 may determine the final alignment result by averaging corresponding coordinates of multiple alignment results obtained by aligning the three-dimensional coordinates determined by the shape determination unit 56 from the image captured by this one imaging unit with the three-dimensional coordinates determined by the shape determination unit 56 from the images captured by the other multiple imaging units.

[0102] [Identifying 3D shapes] The shape specifying unit 56 specifies the three-dimensional shape of the measurement object W. For example, after the conversion specifying unit 55 specifies the conversion value, the shape specifying unit 56 specifies the three-dimensional shape of the measurement object W that is the same as the measurement object W imaged by the imaging control unit 52 so that the conversion specifying unit 55 specifies the conversion value. For example, the shape specifying unit 56 specifies the three-dimensional shape of the measurement object W based on the primary captured image and the secondary captured image generated again by the imaging control unit 52 for the measurement object W that is the same as the measurement object W imaged by the imaging control unit 52 so that the conversion specifying unit 55 specifies the conversion value.

[0103] When the imaging control unit 52 generates the primary captured image and the secondary captured image again, the first fringe projection image and the second fringe projection image are projected onto the measurement object by one or more projection units. In addition, the shape specifying unit 56 may specify a three-dimensional shape of the measurement object different from the measurement object W imaged by the imaging control unit 52 when the conversion specifying unit 55 specifies the conversion value. The shape specifying unit 56 may use a new conversion value specified again by the conversion specifying unit 55 for each measurement of the measurement object, or may specify a conversion value once and then use the conversion value for the next or subsequent measurements.

[0104] When the first determination unit 541 determines a primary absolute phase value corresponding to a primary captured image different from the primary captured image generated by the imaging control unit 52 when the conversion determination unit 55 determines a conversion value, the shape determination unit 56 determines primary coordinates corresponding to the determined primary absolute phase value. When the second determination unit 542 determines a secondary absolute phase value corresponding to a secondary captured image different from the secondary captured image generated by the imaging control unit 52 when the conversion determination unit 55 determines a conversion value, the shape determination unit 56 determines secondary coordinates corresponding to the determined secondary absolute phase value.

[0105] Furthermore, the shape specifying unit 56 may directly use the primary absolute phase value or the secondary absolute phase value used when the conversion specifying unit 55 specifies the conversion value to acquire the shape of the measurement object. The shape specifying unit 56 may specify primary coordinates corresponding to this primary absolute phase value, or may specify secondary coordinates corresponding to this secondary absolute phase value.

[0106] The shape specification unit 56 converts at least one of the specified primary coordinates or secondary coordinates based on the conversion value specified by the conversion specification unit 55. The shape specification unit 56 specifies the three-dimensional shape of the measurement object based on the converted coordinates. For example, the shape specification unit 56 translates the primary coordinates by the translation amount included in the conversion value specified by the conversion specification unit 55 and rotates the primary coordinates by the rotation amount included in the conversion value specified by the conversion specification unit 55, thereby aligning the primary coordinates and the secondary coordinates so that they coincide with each other in the overlapping portion between the primary coordinates and the secondary coordinates. The shape specification unit 56 specifies the three-dimensional shape of the entire measurement object by connecting the converted primary coordinates and the secondary coordinates. When the conversion specification unit 55 specifies the statistics of the conversion value, the shape specification unit 56 may convert the primary coordinates or the secondary coordinates based on the statistics of the conversion value. The statistics is, for example, an average value, but may also be a median. In this way, the shape specifying section 56 can suppress a decrease in the accuracy of alignment of the primary coordinates or the secondary coordinates caused by statistical variations.

[0107] The shape specifying unit 56 may convert the primary coordinates using the conversion values, and then specify an error between the converted primary coordinates and the secondary coordinates. The shape specifying unit 56 may specify an average value of errors for a plurality of primary coordinates included in the measurement object, and determine that the alignment is appropriate when the specified average value is less than a threshold value. On the other hand, the shape specifying unit 56 may determine that the alignment is inappropriate when the specified average value is equal to or greater than the threshold value.

[0108] When the conversion specifying unit 55 specifies a portion of the measurement object where the primary coordinates and the secondary coordinates cannot be made close to each other in the three-dimensional space, the shape specifying unit 56 may specify the three-dimensional shape of the measurement object W excluding the specified portion. In this way, the shape specifying unit 56 can specify the three-dimensional shape of the measurement object W excluding the portion affected by noise or the like. The shape specifying unit 56 may determine that alignment is impossible when the number of portions of the measurement object where the primary coordinates and the secondary coordinates cannot be made close to each other in the three-dimensional space is equal to or greater than a threshold value. In this way, the shape specifying unit 56 can suppress a decrease in the accuracy of alignment when there are many portions affected by noise or the like. After the conversion specifying unit 55 specifies a portion of the measurement object where the primary coordinates and the secondary coordinates cannot be made close to each other in the three-dimensional space by the first alignment, the shape specifying unit 56 performs alignment between the primary coordinates and the secondary coordinates again excluding the specified portion, thereby improving the accuracy of alignment.

[0109] The shape specifying unit 56 may specify primary coordinates corresponding to the same primary captured image as the primary captured image generated by the imaging control unit 52 when the conversion specifying unit 55 specifies the first conversion value, or may specify secondary coordinates corresponding to the same secondary captured image as the secondary captured image generated by the imaging control unit 52 when the conversion specifying unit 55 specifies the second conversion value. The shape specifying unit 56 converts the primary coordinates by the first conversion value and converts the secondary coordinates by the second conversion value, thereby aligning the primary coordinates and the secondary coordinates at an overlapping portion between them. The shape specifying unit 56 may specify the three-dimensional shape of the measurement target W by connecting the converted primary coordinates and the converted secondary coordinates.

[0110] [Display of 3D shape or conversion value] The display control unit 57 displays the three-dimensional shape of the measurement target W identified by the shape identification unit 56 on the display unit 6. When the conversion identification unit 55 identifies a conversion value at every predetermined period, the display control unit 57 may display a transition of the conversion value previously identified by the conversion identification unit 55. For example, the display control unit 57 may display a graph in which the rotation amount or translation amount included in the conversion value identified by the conversion identification unit 55 in the past year is plotted in chronological order. In this way, the display control unit 57 displays the transition of the conversion value, so that the user can grasp the accuracy of the alignment between the primary coordinates and the secondary coordinates and determine whether alignment between the primary coordinates and the secondary coordinates is necessary by referring to the rotation amount or translation amount included in the conversion value.

[0111] [Determination of conversion value by three-dimensional shape measuring device 100] 14 is a flowchart showing a processing procedure for identifying the three-dimensional shape of a measurement object by three-dimensional shape measuring device 100. This processing procedure starts, for example, when measurement of the three-dimensional shape of the measurement object is started. In three-dimensional shape measuring device 100, after conversion specifying unit 55 executes conversion value specifying process (S101), shape specifying unit 56 executes shape specifying process (S102) to specify the three-dimensional shape of the measurement object, and the process ends.

[0112] FIG. 15 is a flowchart showing the processing procedure of the conversion value determination process (S101) of FIG. 14. First, the projection control unit 51 causes the first projection unit 1 to project the first fringe projection image onto the measurement object (S201). The imaging control unit 52 acquires the first fringe image by the first imaging unit 3. The imaging control unit 52 acquires the secondary first fringe image by the second imaging unit 4 (S202). The projection control unit 51 causes the second projection unit 2 to project the second fringe projection image onto the measurement object (S203). The imaging control unit 52 acquires the first two fringe image by the first imaging unit 3. The imaging control unit 52 acquires the secondary second fringe image by the second imaging unit 4 (S204).

[0113] The first determination unit 541 determines first and second direction primary absolute phase values ​​corresponding to each of the plurality of pixels of the first imaging unit 3. The second determination unit 542 determines first and second direction secondary absolute phase values ​​corresponding to each of the plurality of pixels of the second imaging unit 4 (S205). The conversion determination unit 55 determines conversion values ​​for converting the primary coordinates so that the plurality of primary coordinates corresponding to the plurality of primary absolute phase values ​​determined by the first determination unit 541 and the plurality of secondary coordinates corresponding to the plurality of secondary absolute phase values ​​determined by the second determination unit 542 approach each other (S206), and ends the process.

[0114] Fig. 16 is a flowchart showing the processing procedure of the shape identification process (S102) in Fig. 14. The processing procedure of S301 to S305 in Fig. 16 is the same as S201 to S205 in Fig. 15, so the description will be omitted. The shape identification unit 56 converts a plurality of primary coordinates corresponding to a plurality of primary absolute phase values ​​identified by the first identification unit 541 using the conversion value identified by the conversion identification unit 55 (S306). The conversion identification unit 55 connects the plurality of primary coordinates after conversion with a plurality of secondary coordinates corresponding to a plurality of secondary absolute phase values ​​identified by the second identification unit 542, thereby identifying the three-dimensional shape of the entire measurement object (S307).

[0115] <Second embodiment> In the second embodiment, an example in which the three-dimensional shape measuring device 200 includes three or more imaging units will be described. FIG. 17 shows the configuration of the three-dimensional shape measuring device 200 of the second embodiment. The three-dimensional shape measuring device 200 includes an auxiliary imaging unit 201 in addition to the first imaging unit 3 and the second imaging unit 4. The imaging control unit 52 generates a one-way stripe captured image by capturing an image of the measurement object in a state in which the first stripe projection image is projected by the first projection unit 1, using the first imaging unit 3. The imaging control unit 52 generates a three-way stripe captured image by capturing an image of the measurement object in a state in which the first stripe projection image is projected by the first projection unit 1, using the auxiliary imaging unit 201.

[0116] The imaging control unit 52 generates a one-way two-stripe captured image by capturing an image of the measurement object with the second stripe projection image projected by the first projection unit 1 using the first imaging unit 3. The imaging control unit 52 generates a three-way two-stripe captured image by capturing an image of the measurement object with the second stripe projection image projected by the first projection unit 1 using the auxiliary imaging unit 201.

[0117] The imaging control unit 52 generates a secondary first fringe captured image by capturing, by the second imaging unit 4, the measurement object in a state in which the first fringe projection image is projected by the second projection unit 2. The imaging control unit 52 generates a four-way first fringe captured image by capturing, by the auxiliary imaging unit 201, the measurement object in a state in which the first fringe projection image is projected by the second projection unit 2. The imaging control unit 52 generates a secondary second fringe captured image by capturing, by the second imaging unit 4, the measurement object in a state in which the second fringe projection image is projected by the second projection unit 2. The imaging control unit 52 generates a four-way two-fringe captured image by capturing, by the auxiliary imaging unit 201, the measurement object in a state in which the second fringe projection image is projected by the second projection unit 2.

[0118] The first determination unit 541 determines first-order absolute phase values ​​in the first and second directions corresponding to each of the multiple pixels of the first imaging unit 3 based on the images of the first and second patterns in the primary captured image. The first determination unit 541 determines third-order absolute phase values ​​in the first and second directions corresponding to each of the multiple pixels of the auxiliary imaging unit 201 based on the images of the first and second patterns in the triangular single-stripe captured image and the triangular double-stripe captured image.

[0119] The second determination unit 542 determines second-order absolute phase values ​​in the first and second directions corresponding to each of the multiple pixels of the second imaging unit 4 based on the images of the first and second patterns in the secondary captured image. The second determination unit 542 determines fourth-order absolute phase values ​​in the first and second directions corresponding to each of the multiple pixels of the auxiliary imaging unit 201 based on the images of the first and second patterns in the four-way stripe captured image and the four-way stripe captured image.

[0120] When the first absolute phase value identified by the first identification unit 541 is equal to the identified tertiary absolute phase value, the pixel of the first imaging unit 3 corresponding to this first absolute phase value and the pixel of the auxiliary imaging unit 201 corresponding to this tertiary absolute phase value correspond to the same three-dimensional coordinates of the measurement object. The conversion identification unit 55 identifies a plurality of pairs of pixels of the first imaging unit 3 and the auxiliary imaging unit 201 where the first absolute phase value identified by the first identification unit 541 is equal to the identified tertiary absolute phase value. Similarly, the conversion identification unit 55 identifies a plurality of pairs of pixels of the second imaging unit 4 and the auxiliary imaging unit 201 where the plurality of second absolute phase values ​​identified by the second identification unit 542 are equal to the identified quaternary absolute phase value.

[0121] It can be said that the tertiary absolute phase value and the quaternary absolute phase value corresponding to the same pixel of the auxiliary imaging section 201 correspond to the same three-dimensional coordinate on the measurement object. The conversion specifying unit 55 specifies, for a plurality of pixels of the auxiliary imaging section 201, a plurality of pairs of the tertiary absolute phase value and the quaternary absolute phase value corresponding to the same pixel of the auxiliary imaging section 201. The conversion specifying unit 55 refers to the specified pairs of the tertiary absolute phase value and the quaternary absolute phase value, and specifies a plurality of combinations of the first absolute phase value, the third absolute phase value, the quaternary absolute phase value, and the second absolute phase value corresponding to the same three-dimensional coordinate on the measurement object.

[0122] The conversion determination unit 55 refers to the identified combinations and, as in the first embodiment, determines conversion values ​​for converting the primary coordinates or the secondary coordinates so that the primary coordinates corresponding to the primary absolute phase values ​​in the first direction and the second direction identified by the first determination unit 541 and the secondary coordinates corresponding to the secondary absolute phase values ​​in the first direction and the second direction identified by the second determination unit 542 approach each other.

[0123] As in the first embodiment, the shape specifying unit 56 converts at least one of the identified primary coordinates or secondary coordinates based on the conversion value specified by the conversion specifying unit 55. The shape specifying unit 56 specifies the three-dimensional shape of the measurement object based on the converted coordinates.

[0124] A projection image projected by the projection control unit 51 onto the measurement object in order for the conversion specifying unit 55 to specify a plurality of combinations of a first-order absolute phase value, a third-order absolute phase value, a fourth-order absolute phase value, and a second-order absolute phase value corresponding to the same three-dimensional coordinates on the measurement object may be different from a projection image projected by the projection control unit 51 onto the measurement object in order for the conversion specifying unit 55 to specify a plurality of combinations of a first-order absolute phase value, a third-order absolute phase value, a fourth-order absolute phase value, and a second-order absolute phase value corresponding to the same three-dimensional coordinates on the measurement object. A projection image projected by the projection control unit 51 onto the measurement object in order for the shape specifying unit 56 to convert the first coordinates or the second coordinates by the conversion values ​​to specify the three-dimensional shape of the measurement object may be different from a projection image projected by the projection control unit 51 onto the measurement object in order for the conversion specifying unit 55 to specify a plurality of combinations of a first-order absolute phase value, a third-order absolute phase value, a fourth-order absolute phase value, and a second-order absolute phase value corresponding to the same three-dimensional coordinates on the measurement object.

[0125] According to the three-dimensional shape measuring device 200 of the second embodiment, even if a part of the first pattern of the projection image projected from the first projection unit 1 is not reflected in the secondary captured image generated by the second imaging unit 4 due to the unevenness or surface reflectance of the measurement object, the conversion specifying unit 55 can specify a pair of a first absolute phase value and a second absolute phase value corresponding to the same three-dimensional coordinate of the measurement object by using the tertiary captured image and the quaternary captured image generated by the auxiliary imaging unit 201. In this way, in the three-dimensional shape measuring device 200, the first specifying unit 541 and the second specifying unit 542 can more reliably acquire the pair of a first absolute phase value and a second absolute phase value, so that the shape specifying unit 56 can measure the measurement object with higher accuracy.

[0126] <Third embodiment> In the first and second embodiments, an example has been described in which the shape specification unit 56 converts at least one of the identified primary coordinates or secondary coordinates based on the conversion value specified by the conversion specification unit 55. In contrast, in the third embodiment, an example will be described in which a determination unit 301 is provided that determines whether or not a position shift occurs in the primary coordinates or secondary coordinates specified by the shape specification unit 56 based on the conversion value specified by the conversion specification unit 55.

[0127] Fig. 18 shows the configuration of a three-dimensional shape measuring apparatus 300 according to the third embodiment. Compared with the example of Fig. 3, the three-dimensional shape measuring apparatus 300 shown in Fig. 18 differs in that it further includes a determination unit 301. Functional blocks similar to those in Fig. 3 are given the same reference numerals and descriptions thereof will be omitted.

[0128] When the transformation value specified by the transformation specification unit 55 is greater than a predetermined reference value, the determination unit 301 determines that a positional deviation occurs between the primary coordinates specified by the shape specification unit 56 and the secondary coordinates specified by the shape specification unit 56. The reference value is, for example, the transformation value previously specified by the transformation specification unit 55. For example, the determination unit 301 determines that a positional deviation occurs between the primary coordinates and the secondary coordinates when a distance (hereinafter also referred to as a translation amount) by which the primary coordinates included in the transformation value are translated is greater than a translation amount included in the transformation value previously specified by the transformation specification unit 55. On the other hand, when a translation amount by which the primary coordinates included in the transformation value are translated is equal to or less than a translation amount previously specified by the transformation specification unit 55, the determination unit 301 does not determine that a positional deviation occurs between the primary coordinates and the secondary coordinates.

[0129] The determination unit 301 may determine that a positional deviation occurs between the primary coordinates and the secondary coordinates when an angle by which the primary coordinates are rotated (hereinafter also referred to as a rotation amount) included in the transformation value is larger than an amount of rotation included in the transformation value previously specified by the transformation specification unit 55. On the other hand, the determination unit 301 may not determine that a positional deviation occurs between the primary coordinates and the secondary coordinates when an amount of rotation by which the primary coordinates are rotated included in the transformation value is equal to or smaller than an amount of rotation included in the transformation value previously specified by the transformation specification unit 55.

[0130] When the translation amount or rotation amount included in the conversion value is significantly large, there is a possibility that a malfunction such as a position shift has occurred in the projection unit 10, the first imaging unit 3, or the second imaging unit 4. For this reason, when at least one of the translation amount for translating the primary coordinates included in the conversion value and the rotation amount for rotating the primary coordinates included in the conversion value is larger than a predetermined reference value, the determination unit 301 determines that a malfunction has occurred in at least one of the projection unit 10, the first imaging unit 3, or the second imaging unit 4. In this case, when the projection unit and the imaging unit are housed in the same housing, the determination unit 301 may determine that a change has occurred in the overall position or attitude of the housing. Even when the determination unit 301 determines that a position shift has occurred, the shape determination unit 56 may use the currently specified conversion value if the corresponding primary coordinates and secondary coordinates can be satisfactorily aligned using the currently specified conversion value.

[0131] For example, the determination unit 301 determines whether or not a malfunction has occurred in at least one of the projection unit 10, the first imaging unit 3, or the second imaging unit 4, based on the difference or similarity between the translation amount included in the conversion value previously specified by the conversion specification unit 55 and the translation amount included in the conversion value currently specified. For example, the determination unit 301 calculates the square root of the difference between the translation amount [X1, Y1, Z1] included in the conversion value previously specified by the conversion specification unit 55 and the translation amount [X2, Y2, Z2] included in the conversion value currently specified, using the following formula (4):

[0132]

number

[0133] When the square root of the calculated difference is equal to or greater than the translation threshold, the determination unit 301 determines that a malfunction has occurred in at least one of the first imaging unit 3 or the second imaging unit 4. The translation threshold is determined according to, for example, the size of the object to be measured. On the other hand, when the square root of the calculated difference is less than the translation threshold, the determination unit 301 does not determine that a malfunction has occurred in at least one of the first imaging unit 3 or the second imaging unit 4.

[0134] The determination unit 301 determines whether or not a malfunction has occurred in at least one of the projection unit 10, the first imaging unit 3, or the second imaging unit 4 based on the difference or similarity between the amount of rotation included in the conversion value previously specified by the conversion specification unit 55 and the amount of rotation included in the conversion value currently specified. For example, the determination unit 301 calculates the square root of the difference between the amount of rotation included in the conversion value previously specified by the conversion specification unit 55 and the amount of rotation included in the conversion value currently specified. If the square root of the calculated difference is equal to or greater than the rotation threshold, the determination unit 301 determines that a malfunction has occurred in at least one of the first imaging unit 3 or the second imaging unit 4. The rotation threshold is determined according to, for example, the size of the object to be measured. On the other hand, if the square root of the calculated difference is less than the rotation threshold, the determination unit 301 does not determine that a malfunction has occurred in at least one of the first imaging unit 3 or the second imaging unit 4.

[0135] The determination unit 301 may also determine the similarity between the primary coordinates and the secondary coordinates by calculating the coordinate difference between each point of the primary coordinates and each point of the corresponding secondary coordinates after the shape determination unit 56 performs alignment between the primary coordinates and the secondary coordinates by converting the primary coordinates or the secondary coordinates using the conversion value. The similarity is calculated by various known methods based on the calculated coordinate differences. When the determined similarity is equal to or less than a threshold, the determination unit 301 determines that a defect has occurred in at least one of the projection unit, the first imaging unit 3, or the second imaging unit 4. The threshold is determined, for example, according to a tolerance for error in a specified shape measurement or the total number of points for which the coordinate difference has been calculated.

[0136] When the identified similarity is equal to or less than the threshold value, the determination unit 301 does not determine that a malfunction has occurred in at least one of the projection unit, the first imaging unit 3, or the second imaging unit 4. In this way, when the accuracy of alignment has decreased due to a malfunction in the projection unit or the like, the determination unit 301 can make the user understand that a malfunction has occurred in the projection unit or the like.

[0137] The display control unit 302 (corresponding to an output unit) outputs the determination result of the determination unit 301 as to whether or not a positional shift has occurred. In the example of Fig. 18, the display control unit 302 outputs the determination result to the display unit 6. In this way, the display control unit 302 outputs the determination result of the determination unit 301 as to whether or not a positional shift has occurred in the primary coordinates or the secondary coordinates, so that the user can easily grasp that the state of alignment of the three-dimensional shape data has deteriorated due to the passage of time or the influence of a temperature change, etc.

[0138] [Processing procedure for determining whether or not misalignment has occurred] 19 is a flowchart showing a process for determining whether or not a positional deviation occurs in the primary coordinates or secondary coordinates in the three-dimensional shape measuring device 300. This process is started, for example, every time a predetermined period of time elapses. The predetermined period of time is determined, for example, based on the difference between a conversion value previously specified by the conversion specifying unit 55 and a conversion value previously specified by the conversion specifying unit 55. As an example, the larger the difference, the shorter the predetermined period of time is determined.

[0139] Since S401 to S406 in Fig. 19 are similar to S201 to S206 in Fig. 15, the description will be omitted. The determination unit 301 determines whether or not the translation amount by which the primary coordinate is translated in the transformation value specified by the transformation specification unit 55 is equal to or less than the translation amount included in the transformation value specified previously (S407).

[0140] When the determination unit 301 determines that the translation amount by which the primary coordinates are translated in the transformation value is equal to or less than the translation amount included in the previously specified transformation value (YES in S407), it determines whether or not the rotation amount by which the primary coordinates are rotated in the transformation value is equal to or less than the rotation amount included in the previously specified transformation value (S408).When the determination unit 301 determines that the rotation amount by which the primary coordinates are rotated in the transformation value is equal to or less than the rotation amount included in the previously specified transformation value (YES in S408), it determines that no positional deviation occurs between the primary coordinates and the secondary coordinates (S409), and ends the process.

[0141] When the determination unit 301 determines in S407 that the translation amount by which the primary coordinates are translated in the transformation value is greater than the translation amount included in the previously specified transformation value (NO in S407), it determines that a positional deviation has occurred between the primary coordinates and the secondary coordinates (S410).When the determination unit 301 determines in S408 that the rotation amount by which the primary coordinates are rotated is greater than the rotation amount included in the previously specified transformation value (NO in S408), it determines that a positional deviation has occurred between the primary coordinates and the secondary coordinates (S410).

[0142] [Effects of 3D shape measuring devices 100-300] According to the three-dimensional shape measuring apparatuses 100-200 of the first to third embodiments, the conversion specifying unit 55 specifies a conversion value based on the primary captured image and the secondary captured image of the measurement object, and the shape specifying unit 56 uses the conversion value to convert the primary coordinates, and then aligns the converted primary coordinates with the secondary coordinates to specify the three-dimensional shape of the measurement object. Therefore, the shape specifying unit 56 can suppress the accuracy of aligning the primary coordinates with the secondary coordinates from decreasing due to the influence of the passage of time or temperature change. Furthermore, when the conversion value is larger than the previously specified conversion value, the three-dimensional shape measuring apparatus 300 outputs information indicating that a position shift has occurred, so that the three-dimensional shape measuring apparatus 300 can recognize that there is a possibility that an error has occurred in the measurement result of the three-dimensional shape. Therefore, according to the three-dimensional shape measuring apparatuses 100-300, it is possible to suppress the measurement of the three-dimensional shape in a state where the accuracy of aligning multiple three-dimensional shape data has decreased.

[0143] Although the present invention has been described above using the embodiments, the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by distributing or integrating functionally or physically in any unit. In addition, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effect of the new embodiment resulting from the combination combines the effect of the original embodiment.

[0144] Since the conversion specification unit 55 specifies the correspondence between pixel positions between multiple imaging units, the shape specification unit 56 may calculate a new three-dimensional shape of the object to be measured based on the correspondence specified by the conversion specification unit 55.

[0145] A plurality of first-order absolute phase values ​​corresponding to a plurality of pixels of the first imaging unit 3 and a plurality of second-order absolute phase values ​​corresponding to a plurality of pixels of the second imaging unit 4 can be treated as two types of images because values ​​in two directions are obtained for each pixel. The conversion specification unit 55 may convert these images into images with a lower resolution. The conversion specification unit 55 can find a position on this low-resolution absolute phase value image where the absolute phase values ​​on the imaging unit 3 side and the imaging unit 4 side roughly correspond to each other. Next, the conversion specification unit 55 searches for a corresponding position in detail on the original absolute phase value image, using the corresponding position on the low-resolution absolute phase value image as an initial value.

[0146] In this way, the conversion specification unit 55 can find the corresponding position more efficiently and accurately by using the image of the absolute phase values ​​in two directions. The conversion specification unit 55 may create an image with a lower resolution from the low-resolution image as necessary and repeat a similar search. The conversion specification unit 55 may find the conversion value based on the corresponding position found in this way.

[0147] The conversion specification unit 55 may simply thin out the image to obtain the low-resolution image, but may also average a number of pixels. By using the low-resolution image, the conversion specification unit 55 is less susceptible to the effects of noise contained in the absolute phase value when roughly finding corresponding points, and can find more corresponding points more accurately, thereby determining the conversion value with higher accuracy.

[0148] In a configuration using a plurality of imaging units, the conversion specification unit 55 specifies whether a three-dimensional shape specified from an image captured by which imaging unit can be aligned with a three-dimensional shape specified from an image captured by which imaging unit. The conversion specification unit 55 performs a determination of feasibility of alignment between a three-dimensional shape corresponding to a certain imaging unit and a three-dimensional shape corresponding to another imaging unit. For example, the conversion specification unit 55 determines that alignment is possible when a sufficient number of corresponding points for alignment can be obtained and the error between the primary coordinates and the secondary coordinates after conversion using the conversion value is relatively small. The conversion specification unit 55 may search for a combination of imaging units that can perform the best alignment by repeatedly performing this determination while changing the combination of imaging units. [Explanation of symbols]

[0149] 1 1st projection section 2 Second projection section 3 First imaging section 4 Second imaging section 5. Control section 6 Display section 7 Memory section 10 Projection section 10a Frame 10b Frame 31 Lens 32 Image sensor 41 Lens 42 Image sensor 51 Projection control unit 52 Imaging control section 53 Area division part 54 Specific part 55 Conversion Specific Part 56 Shape identification part 57 Display control section 81 Third Imaging Unit 82 4th Imaging Unit 100 Three-dimensional shape measuring device 200 Three-dimensional shape measuring device 201 Auxiliary imaging unit 300 3D shape measuring device 301 Judgment section 302 Display control unit 541 1st Specific Part 542 2nd Specific Part

Claims

1. a projection unit that projects onto a measurement object a first fringe projection image having a first pattern whose luminance changes along a first direction and a second fringe projection image having a second pattern whose luminance changes along a second direction different from the first direction; a first imaging unit that generates a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon, and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon; a first determination unit that determines a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; a second imaging unit that generates a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon, and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon; a second identification unit that identifies a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; a conversion specifying unit that specifies a conversion value for converting the primary coordinates or the secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value in a three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value approach each other in the three-dimensional space; a shape determination unit that transforms the primary coordinates or the secondary coordinates based on the transformation value, and determines a three-dimensional shape of the measurement object based on the transformed coordinates; A three-dimensional shape measuring apparatus comprising:

2. The transformation specification unit specifies the transformation value including a translation amount by which the primary coordinates are translated so as to match the primary coordinates with the secondary coordinates, and a rotation amount by which the primary coordinates are rotated so as to match the primary coordinates with the secondary coordinates. The three-dimensional shape measuring apparatus according to claim 1 .

3. A region dividing unit divides a three-dimensional region including a plurality of the primary coordinates corresponding to the plurality of the primary absolute phase values ​​identified by the first identifying unit into a plurality of primary partial regions, and divides a three-dimensional region including a plurality of the secondary coordinates corresponding to the plurality of the secondary absolute phase values ​​identified by the second identifying unit into a plurality of secondary partial regions, the transformation specification unit specifies, for each of the plurality of primary partial regions, the transformation value for transforming the primary coordinate or the secondary coordinate such that the primary partial region, the primary coordinate included in the primary partial region, and the secondary coordinate included in the secondary partial region corresponding to the same absolute phase value as the primary coordinate are approximated in the three-dimensional space; The three-dimensional shape measuring apparatus according to claim 1 or 2.

4. The first determination unit determines a plurality of the first absolute phase values ​​in a plurality of measurements, The second determination unit determines a plurality of the second absolute phase values ​​in the plurality of measurements, the transformation specifying unit specifies the transformation values ​​for transforming the primary coordinates or the secondary coordinates such that the primary coordinates corresponding to the primary absolute phase values ​​corresponding to the multiple measurements in the three-dimensional space and the secondary coordinates corresponding to the secondary absolute phase values ​​equal to the primary absolute phase values ​​are close to each other in the three-dimensional space, and specifies statistics of the specified transformation values; The shape specification unit converts the primary coordinates or the secondary coordinates based on the specified statistics of the conversion value. The three-dimensional shape measuring apparatus according to claim 1 or 2.

5. the transformation specifying unit specifies a portion in the three-dimensional space where the primary coordinate corresponding to the primary absolute phase value in the three-dimensional space and the secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value cannot be made close to each other, based on the transformation value. The three-dimensional shape measuring apparatus according to claim 1 or 2.

6. the first identification unit extracts a primary feature from the first stripe captured image generated by the first imaging unit and the second stripe captured image generated by the first imaging unit, and identifies a primary reliability indicating the reliability of the primary absolute phase value based on the extracted primary feature; the second identification unit extracts a secondary feature from the first stripe captured image generated by the second imaging unit and the second stripe captured image generated by the second imaging unit, and identifies a secondary reliability indicating the reliability of the secondary absolute phase value based on the extracted secondary feature; the conversion identification unit identifies three-dimensional coordinates included in the measurement object by statistical processing based on the primary reliability and the secondary reliability. The three-dimensional shape measuring apparatus according to claim 1 or 2.

7. the first identification unit extracts a primary feature from the first fringe captured image generated by the first imaging unit and the second fringe captured image generated by the first imaging unit, and identifies a primary reliability indicating reliability of the primary absolute phase value based on the extracted primary feature; the second identification unit extracts secondary features from the first fringe captured image generated by the second imaging unit and the second fringe captured image generated by the second imaging unit, and identifies a secondary reliability indicating reliability of the secondary absolute phase value based on the extracted secondary features; the transformation specification unit specifies the three-dimensional shape of the measurement object by selecting, for each primary coordinate, either the primary coordinate after alignment or the secondary coordinate transformed in the alignment so as to approach the primary coordinate, based on a comparison result between the primary reliability and the secondary reliability. The three-dimensional shape measuring apparatus according to claim 1 or 2.

8. the conversion specification unit specifies a timing for next specifying the conversion value based on a result of comparing the specified conversion value with a previously specified conversion value; The three-dimensional shape measuring apparatus according to claim 1 or 2.

9. The conversion specification unit specifies the conversion value for each predetermined period of time, a display control unit that displays a transition of the conversion value previously determined by the conversion determination unit, The three-dimensional shape measuring apparatus according to claim 1 or 2.

10. A part of the imaging range of the first imaging unit does not overlap with the imaging range of the second imaging unit. The three-dimensional shape measuring apparatus according to claim 1 or 2.

11. a projection unit that projects a first fringe projection image having a first pattern whose luminance changes along a first direction and a second fringe projection image having a second pattern whose luminance changes along a second direction onto a measurement object; a first imaging unit that generates a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon, and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon; a first determination unit that determines a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; a second imaging unit that generates a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon, and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon; a second identification unit that identifies a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; a conversion specifying unit that specifies a conversion value for converting the primary coordinates or the secondary coordinates such that a primary coordinate corresponding to the primary absolute phase value in a three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value approach each other in the three-dimensional space; a determination unit that determines that a positional deviation occurs between the primary coordinates and the secondary coordinates when the converted value is greater than a predetermined reference value; an output unit that outputs a determination result of the determination unit; A three-dimensional shape measuring apparatus comprising:

12. After performing the alignment between the primary coordinates and the secondary coordinates, a coordinate difference for each corresponding point is calculated to identify a similarity between the primary coordinates and the secondary coordinates, and if the similarity is equal to or less than a threshold, it is determined that a malfunction has occurred in at least one of the projection unit, the first imaging unit, or the second imaging unit. The three-dimensional shape measuring apparatus according to claim 10.

13. The computer executes Projecting a first fringe projection image having a first pattern whose luminance varies along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance varies along a second direction onto the measurement object; A step of generating a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon by a first imaging unit; determining a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; generating a first fringe image obtained by imaging the measurement object in a state where the first fringe projection image is projected, and a second fringe image obtained by imaging the measurement object in a state where the second fringe projection image is projected, by a second imaging unit; determining a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; identifying a transformation value for transforming the primary coordinate or the secondary coordinate such that a primary coordinate corresponding to the primary absolute phase value in a three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are approximated in the three-dimensional space; transforming the primary coordinates or the secondary coordinates based on the transformation values, and identifying a three-dimensional shape of the measurement object based on the transformed coordinates; A three-dimensional shape measuring method comprising:

14. The computer executes Projecting a first fringe projection image having a first pattern whose luminance varies along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance varies along a second direction onto the measurement object; A step of generating a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon by a first imaging unit; determining a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; generating a first fringe image obtained by imaging the measurement object in a state where the first fringe projection image is projected, and a second fringe image obtained by imaging the measurement object in a state where the second fringe projection image is projected, by a second imaging unit; determining a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; identifying a transformation value for transforming the primary coordinate or the secondary coordinate such that a primary coordinate corresponding to the primary absolute phase value in a three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are approximated in the three-dimensional space; determining that a positional deviation occurs between the primary coordinates and the secondary coordinates when the converted value is greater than a predetermined reference value; outputting a result of the determination as to whether or not the positional deviation has occurred; A three-dimensional shape measuring method comprising:

15. On the computer, Projecting a first fringe projection image having a first pattern whose luminance varies along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance varies along a second direction onto the measurement object; A step of generating a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon by a first imaging unit; determining a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; generating a first fringe image obtained by imaging the measurement object in a state where the first fringe projection image is projected, and a second fringe image obtained by imaging the measurement object in a state where the second fringe projection image is projected, by a second imaging unit; determining a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; identifying a transformation value for transforming the primary coordinate or the secondary coordinate such that a primary coordinate corresponding to the primary absolute phase value in a three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are approximated in the three-dimensional space; transforming the primary coordinates or the secondary coordinates based on the transformation values, and identifying a three-dimensional shape of the measurement object based on the transformed coordinates; A program that executes the following.

16. On the computer, Projecting a first fringe projection image having a first pattern whose luminance varies along a first direction onto a measurement object; projecting a second fringe projection image having a second pattern whose luminance varies along a second direction onto the measurement object; A step of generating a first fringe captured image obtained by capturing an image of the measurement object with the first fringe projection image projected thereon and a second fringe captured image obtained by capturing an image of the measurement object with the second fringe projection image projected thereon by a first imaging unit; determining a first absolute phase value corresponding to each of a plurality of pixels of the first imaging unit based on an image of the first pattern in the first fringe captured image generated by the first imaging unit and an image of the second pattern in the second fringe captured image generated by the first imaging unit; generating a first fringe image obtained by imaging the measurement object in a state where the first fringe projection image is projected, and a second fringe image obtained by imaging the measurement object in a state where the second fringe projection image is projected, by a second imaging unit; determining a secondary absolute phase value corresponding to each of a plurality of pixels of the second imaging unit based on an image of the first pattern in the first fringe captured image generated by the second imaging unit and an image of the second pattern in the second fringe captured image generated by the second imaging unit; identifying a transformation value for transforming the primary coordinate or the secondary coordinate such that a primary coordinate corresponding to the primary absolute phase value in a three-dimensional space and a secondary coordinate corresponding to the secondary absolute phase value equal to the primary absolute phase value are approximated in the three-dimensional space; determining that a positional deviation occurs between the primary coordinates and the secondary coordinates when the converted value is greater than a predetermined reference value; outputting a result of the determination as to whether or not the positional deviation has occurred; A program that executes the following.

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