Data generation method and data generation system

Abstract

To provide a technique suitable for shape measurement of a tube body internal surface.SOLUTION: A data generation system 100 comprises: a spatial light modulator 140 and the like that continuously create images having a periodic pattern projected on a measurement target surface while shifting the phase for every predetermined time; an image fiber 110 that can project the created images toward the measurement target surface; an image pickup device 150 that can photograph the images projected on the measurement target surface through the image fiber 110; and an analysis and reconfiguration unit 164 that generates three-dimensional data according to the shape of the measurement target surface based on three-dimensional Fourier transformation on time and a two-dimensional space obtained from a plurality of photographed images photographed by the image pickup device 150 through a process in which a photographing position of the image fiber 110 relatively stops and changes, and a plurality of photographing positions at which the photographed images are obtained.SELECTED DRAWING: Figure 1

Claims

1. The first step involves performing an operation to capture an image by shifting the phase of an image with a periodic pattern projected onto the surface to be measured at predetermined time intervals, while relatively stopping or changing the projection position and capture position of the image relative to the surface to be measured. The second step involves generating three-dimensional data corresponding to the shape of the surface to be measured, based on the multiple projection and shooting positions in the first step and the time and three-dimensional Fourier analysis in two-dimensional space obtained from the multiple captured images. A data generation method having the following characteristics.

2. In the data generation method described in claim 1, In the first step described above, When light modulated as a distribution of light intensity representing a periodic pattern of an image is projected from the end face of an image fiber onto the surface to be measured, and the reflected light from the surface to be measured is incident on the end face through a pinhole virtually placed at a position away from the end face in the projection direction, thereby forming an image on a virtual imaging surface, the coordinates on the virtual imaging surface are defined on the extension line connecting the position of the surface to be measured from which the reflected light was emitted and the position of the pinhole, and imaging is performed. In the second step described above, A data generation method characterized by determining coordinates representing the position of the surface to be measured based on a three-dimensional Fourier analysis in time and two-dimensional space of the image formed on the virtual imaging surface in the first step.

3. In the data generation method described in claim 1, In the first step described above, A first optical system is used that projects light modulated as a distribution of light intensity, in which the periodic pattern of the image is generated, onto the surface to be measured from the end face of a first image fiber, and a second optical system is used that takes images by causing the reflected light from the surface to be measured, when light is projected from the end face of the first image fiber, to enter the end face of a second image fiber. In the second step described above, A data generation method characterized by determining coordinates representing the position of the surface to be measured based on a three-dimensional Fourier analysis in time and two-dimensional space of an image captured using the second optical system.

4. In the data generation method described in claim 3, In the first step described above, A data generation method characterized by arranging a rod lens on the end face of the second image fiber to cause reflected light from the surface to be measured to be incident on the end face through a principal point located at a position offset in the projection direction from the end face, and then performing imaging.

5. In the data generation method according to any one of claims 1 to 4, In the second step described above, A data generation method characterized by determining the projection position and the shooting position by continuously projecting and capturing images onto the surface to be measured, starting from the shooting position relative to a reference plane.

6. In the data generation method according to claim 3 or 4, In the first step described above, Using multiple second image fibers arranged in parallel, imaging is performed using multiple second optical systems. In the second step described above, A data generation method characterized by determining the projection position and the shooting position by continuously projecting and capturing images onto the surface to be measured from a starting point shooting position determined by the stereo method using multiple images captured by multiple second optical systems.

7. In the data generation method according to any one of claims 1 to 4, In the second step described above, A data generation method characterized by determining the projection position and shooting position of an image relative to a surface to be measured based on the magnetic field distribution of a magnetic marker that moves in accordance with the movement of the projection position and shooting position.

8. An image generation means that continuously generates an image having a periodic pattern projected onto the surface to be measured, shifting the phase at predetermined time intervals, The first image fiber, which can project the image generated by the image generation means toward the surface to be measured, An imaging means capable of capturing an image projected onto the surface to be measured through a second image fiber, A three-dimensional Fourier analysis in time and two-dimensional space obtained from a plurality of captured images taken by the imaging means through the process in which the projection position and shooting position of the images from each image fiber on the surface to be measured are relatively stopped or changed, and a generation means that generates three-dimensional data corresponding to the shape of the surface to be measured based on the plurality of projection positions and shooting positions from which each captured image was obtained. A data generation system equipped with this system.

9. In the data generation system according to claim 8, A data generation system characterized in that the first image fiber and the second image fiber are composed of a single image fiber that projects and captures images through a common optical system.

10. In the data generation system according to claim 8, A data generation system characterized in that the first image fiber and the second image fiber are composed of separate image fibers that project and capture images through their respective optical systems.

11. In the data generation system according to any one of claims 8 to 10, The imaging means is An image sensor having an imaging surface, A pinhole is positioned on the image plane on the incident side of the imaging surface of the aforementioned image sensor, The image sensor has a lens that forms an image on the surface on the incident side of the imaging surface through the pinhole, A data generation system characterized in that, when an image is projected from the end face of the first image fiber onto the surface to be measured, it is possible to generate a virtual situation in which the light reflected from the surface to be measured is incident on the end face of the second image fiber through a pinhole virtually placed at a position away from the end face in the projection direction, thereby forming an image on a virtual imaging surface.

12. In the data generation system according to claim 11, The generating means is A data generation system characterized by defining coordinates on the virtual imaging surface on the extension line connecting the position of the surface to be measured that emitted the reflected light and the position of the virtually placed pinhole, thereby determining coordinates representing the position of the surface to be measured based on the time and three-dimensional Fourier analysis in two-dimensional space of the image formed on the virtual imaging surface.

13. In the data generation system according to any one of claims 8 to 12, The generating means is A data generation system characterized by continuously determining the projection position and shooting position of an image on the surface to be measured, starting from the shooting position of the second image fiber relative to the reference plane.

14. In the data generation system according to any one of claims 8 to 12, A magnetic marker is installed on each of the aforementioned image fibers, and each magnetic marker follows the changes in the projection position and capture position of the image by each of the aforementioned image fibers. Multiple magnetic sensors are arranged around the surface to be measured and detect the magnetic field distribution of the magnetic marker at multiple different locations. A detection means for determining the projection position and shooting position of the image on the surface to be measured for each image fiber based on the detection results from the multiple magnetic sensors. A data generation system that also includes additional features.

15. In the data generation system according to claim 8, The first image fiber is The image generated by the image generation means is projected through the first optical system. The imaging means is An image is captured through the second image fiber, which constitutes a second optical system separate from the first optical system. The generating means is A data generation system characterized by generating three-dimensional data corresponding to the shape of the surface to be measured, based on a three-dimensional Fourier analysis in time and two-dimensional space obtained from a plurality of captured images taken by the imaging means through a process in which the projection position of the image of the first image fiber and the shooting position of the image of the second image fiber relative to the surface to be measured are stopped or changed, and based on the plurality of projection positions and shooting positions from which each captured image was obtained.

16. In the data generation system according to claim 15, A data generation system further comprising a rod lens attached to the end face of the second image fiber, which causes reflected light from the surface to be measured to be incident on the end face through a principal point located at a position offset in the projection direction from the end face.

17. In the data generation system according to claim 15 or 16, The imaging means is The system includes a plurality of the second image fibers arranged in parallel, The generating means is A data generation system characterized by determining the starting point of the imaging position by stereo method using multiple images captured using multiple second image fibers, and then continuously determining the projection position and imaging position of the image on the surface to be measured from that starting point.

18. In the data generation system according to any one of claims 15 to 17, The image generation means is A data generation system characterized by generating images having a periodic pattern by changing the phase difference between two polarization components of laser light, and then interfering the two polarization components with each other at the end face of the first image fiber on the side into which the light is incident after branching the two polarization components into separate optical paths, thereby continuously generating images with a phase shift at predetermined time intervals.

19. In the data generation system according to any one of claims 15 to 17, The image generation means is A polarizer that polarizes unpolarized light into two components, A modulator that changes the phase difference between two polarization components polarized by the aforementioned polarizer, A polarization-separating polarizer that separates the two polarization components, An optical device that merges the two polarization components separated by the polarization-separating polarizer on the second image fiber. A data generation system characterized by having the following features.

20. In the data generation system according to any one of claims 15 to 17, The image generation means is A data generation system characterized by having a microdisplay that generates an image projected by the second image fiber toward the surface to be measured and causes the image to be incident on the second image fiber.

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