Stereoscopic imaging system, stereoscopic imaging method, and stereoscopic imaging program

Abstract

To acquire a static stereoscopic image of a rotating object.SOLUTION: A stereoscopic imaging system 100 includes a first rotation device 121, a second rotation device 122, and a control device 150 for controlling the first rotation device 121 and the second rotation device 122. The control device 150 includes the rotation angle control unit 151 that rotates the rotary optical system 110, the angle acquisition unit 152 that acquires the first angle θ 1 of the first optical axis 101 and the second angle θ 2 of the second optical axis 102 with respect to the rotation axis 103, the image acquisition unit 153 that acquires the first rotated image and the second rotated image, the first correction image and the second correction image obtained by capturing the calibration target, the first object image corresponding to the rotation angle at which the first correction image is captured, the first object image corresponding to the rotation angle at which the second correction image is captured, the first angle θ 1, and the second angle θ 2. And a stereoscopic image derivation unit 154 that derives a still stereoscopic image of the rotating target object 200 on the basis of the distance information SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stereoscopic imaging system including at least two rotational optical systems that rotate to rotate an image, a stereoscopic imaging method using the stereoscopic imaging system, and a stereoscopic imaging program used in the stereoscopic imaging system. [Background technology]

[0002] The inventor has already filed a patent application for a technology in which a rotating optical system such as a Dove prism is rotated by an image rotation device relative to a rotating object, and the object is imaged by an imaging device while the object is kept relatively stationary (Patent Document 1). This technology makes it easy to arrange the rotational optical axis of the rotating optical system and the imaging optical axis of the imaging device coaxially, making it possible to obtain a still image of the rotating object without blurring. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-124253 Summary of the Invention [Problem to be solved by the invention]

[0004] The inventors have come up with the idea of ​​obtaining a solid three-dimensional image of an object based on still images of a rotating object captured from a plurality of directions, and have been conducting extensive research and experiments.

[0005] However, in order to obtain a stationary three-dimensional image of a rotating object, it is necessary to capture the image from an angle relative to the object's axis of rotation, making it difficult to obtain a blur-free three-dimensional image of the rotating object.

[0006] The present invention is based on the findings of the inventors and provides a stereoscopic imaging system, a stereoscopic imaging method, and a stereoscopic imaging program that can acquire a stereoscopic image with reduced blur of a rotating object. [Means for solving the problem]

[0007] A stereoscopic imaging system according to one aspect of the present invention includes a first rotation device and a second rotation device that are image rotation devices that rotate a rotational optical system to rotate an image, the first rotation device arranged so that a first optical axis that is an optical axis of the first rotation device and a second optical axis that is an optical axis of the second rotation device intersect at one point, and a control device that controls the second rotation device, respectively. The control device includes a rotation angle control unit that rotates the rotational optical systems by a predetermined rotation angle, an angle acquisition unit that acquires a first angle that is an angle of the first optical axis with respect to a rotation axis of a rotating object, and a second angle that is an angle of the second optical axis with respect to the rotation axis, and a first imaging unit that captures a first rotated image by the first rotation device. and a stereoscopic image derivation unit that derives a stationary stereoscopic image of the rotating object based on a first corrected image, which is the first rotated image obtained by imaging the calibration target at a predetermined rotation angle, and a second corrected image, which is the second rotated image, and a first object image, which is the first rotated image obtained by imaging a rotating object at a predetermined frame rate, the first object image corresponding to the rotation angle at which the first corrected image was captured, and the first object image corresponding to the rotation angle at which the second corrected image was captured, and the first angle and the second angle.

[0008] One aspect of the present invention is a stereoscopic image capturing method, which is implemented on a first rotation device and a second rotation device that are image rotating devices that rotate a rotational optical system to rotate an image, the first rotation device and the second rotation device being arranged so that a first optical axis that is an optical axis of the first rotation device and a second optical axis that is an optical axis of the second rotation device intersect at one point, wherein a rotation angle control unit rotates the rotational optical systems by a predetermined rotation angle, and an angle acquisition unit acquires a first angle that is an angle of the first optical axis with respect to a rotation axis of a rotating object and a second angle that is an angle of the second optical axis with respect to the rotation axis, and a first image capturing unit captures a first rotated image by the first rotation device. The image acquisition unit acquires a first rotated image from an imaging device, acquires a second rotated image from a second imaging device that captures a second rotated image by the second rotation device, and a first corrected image which is the first rotated image obtained by imaging the calibration target at a predetermined rotation angle, and a second corrected image which is the second rotated image, and a first object image which is the first rotated image obtained by imaging a rotating object at a predetermined frame rate, and a second object image which is the second rotated image, the first object image corresponding to the rotation angle at which the first corrected image was captured, and the first object image corresponding to the rotation angle at which the second corrected image was captured, and a static three-dimensional image of the object rotating based on the first angle and the second angle.

[0009] A stereoscopic image capturing program according to one aspect of the present invention is a stereoscopic image capturing method implemented on a first rotation device and a second rotation device, which are image rotating devices that rotate a rotational optical system to rotate an image, and which are arranged so that a first optical axis that is an optical axis of the first rotation device and a second optical axis that is an optical axis of the second rotation device intersect at one point, the method including: a rotation angle control unit rotating the rotational optical systems by a predetermined rotation angle, an angle acquisition unit acquiring a first angle that is an angle of the first optical axis with respect to a rotation axis of a rotating object, and a second angle that is an angle of the second optical axis with respect to the rotation axis, and a first rotation angle from a first imaging device that captures a first rotated image by the first rotation device. The processor is caused to execute a stereoscopic image capturing method in which an image capturing unit acquires a rotated image from a second imaging device that captures a second rotated image by the second rotation device, and an image capturing unit acquires a second rotated image from the second imaging device, and a first corrected image which is a first rotated image captured of the calibration target at a predetermined rotation angle, and a second corrected image which is a second rotated image, and a first object image which is a first rotated image captured of a rotating object at a predetermined frame rate, and a second object image which is a second rotated image, the first object image corresponding to the rotation angle at which the first corrected image was captured, and the first object image corresponding to the rotation angle at which the second corrected image was captured, and a still stereoscopic image of the object rotating based on the first angle and the second angle. [Effects of the Invention]

[0010] According to the present invention, the optical axes of a plurality of imaging devices can be made to pass through a single point on the rotation axis of the image rotating device, thereby obtaining a still stereoscopic image with reduced blur of the rotating object. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a stereoscopic imaging system together with an object. [Figure 2] FIG. 2 is an exploded perspective view of the first rotation device. [Figure 3] FIG. 3 is a cross-sectional view of the first rotating device. [Figure 4] FIG. 4 is a block diagram showing the functional configuration of the control device. [Figure 5] FIG. 5 is a perspective view showing a state in which a corrected image is being acquired by the stereoscopic imaging system. [Figure 6] FIG. 6 is a flowchart showing the flow of acquiring a corrected image. [Figure 7] FIG. 7 is a flowchart showing the flow of acquiring a three-dimensional image of an object. DETAILED DESCRIPTION OF THE INVENTION

[0012] Hereinafter, embodiments of a stereoscopic imaging system, a stereoscopic imaging method, and a stereoscopic imaging program according to the present invention will be described with reference to the drawings. Note that the following embodiments are presented as examples for explaining the present invention and are not intended to limit the present invention. For example, the shapes, structures, materials, components, relative positional relationships, connection states, numerical values, mathematical formulas, the content of each step in a method, and the order of each step shown in the following embodiments are merely examples and may include content not described below. Furthermore, while geometric expressions such as "parallel" and "orthogonal" may be used, these expressions do not imply mathematical precision and include substantially acceptable errors, deviations, and the like. Furthermore, expressions such as "simultaneous" and "identical" also include substantially acceptable ranges.

[0013] The drawings are schematic diagrams in which emphasis, omission, or adjustment of proportions is appropriately made for the purpose of explaining the present invention, and differ from the actual shapes, positional relationships, and proportions. The X-axis, Y-axis, and Z-axis shown in the drawings are Cartesian coordinates arbitrarily set for the purpose of explaining the drawings. In other words, the Z-axis is not necessarily an axis along the vertical direction, and the X-axis and Y-axis are not necessarily located within a horizontal plane.

[0014] In addition, in the following, multiple inventions may be collectively described as one embodiment, and some of the contents described below may be described as optional components related to the present invention.

[0015] Furthermore, the flowchart is an example, and even if the processing flow is different, such as the order of processing being different, multiple processes being integrated, or one process being separated, it may still be included in the embodiments of the present invention.

[0016] 1 is a perspective view showing a stereoscopic image capturing system 100 together with an object 200. The stereoscopic image capturing system 100 is a system that creates a still stereoscopic image of a rotating object 200 using images captured by a first imaging device 201 and a second imaging device 202, and includes a first rotation device 121, a second rotation device 122, and a control device 150. In this embodiment, the stereoscopic image capturing system 100 includes a first adapter 131 and a second adapter 132.

[0017] The object 200 is not particularly limited. Examples of the object 200 include a wheel, a windmill, a waterwheel, a turbine, and the like, which are rigid bodies that rotate around a fixed axis of rotation. The object 200 may also be a fluid. Specifically, the object 200 may be a fluid that has been visualized as it passes through a circular or arc-shaped flow path. An example of a visualization process is a fluid in which particles that emit light when exposed to excitation light or self-luminous (phosphorescent) particles are dispersed. Furthermore, the rotation does not necessarily mean a continuous rotation in a fixed direction, but may also be a rotation of less than 360° or a rotational oscillation within a predetermined range.

[0018] "Taking an image in a stationary state" does not only refer to an image of the rotating object 200 taken as if it were stationary. For example, in the case of a fluid, the case where the fluid passing through a part of the flow path is imaged in a stationary state but the other parts are not imaged in a stationary state is also included in the meaning of "taking an image in a stationary state."

[0019] The imaging devices including the first imaging device 201 and the second imaging device 202 are not particularly limited as long as they can visualize an image formed by an optical system. The imaging device may be a digital camera, a film camera, or the like. The imaging device may also be a still camera, a video camera, or the like. The imaging device may also visualize infrared light, ultraviolet light, or the like other than visible light. In this embodiment, the imaging device is a digital video camera capable of capturing still images, and includes an imaging unit having an imaging element arranged perpendicular to the imaging optical axis, and an imaging optical system including a lens, an aperture, and the like. The imaging device is configured such that the imaging element, lens, and the like are arranged to realize a straight imaging optical axis that passes through the central axis of the imaging optical system and reaches the center of the rectangular imaging element. The imaging optical axis may be bent by a mirror or the like.

[0020] Although the imaging devices are described as not being included in the stereoscopic imaging system 100, imaging devices such as the first imaging device 201 and the second imaging device 202 may be included in the stereoscopic imaging system 100.

[0021] Fig. 2 is an exploded perspective view of first rotation device 121. Fig. 3 is a cross-sectional view of first rotation device 121. The structure of second rotation device 122 is similar to that of first rotation device 121. First rotation device 121 and second rotation device 122 are image rotation devices that rotate the rotating optical system 110 to rotate the image.

[0022] The rotating optical system 110 is an optical system that can optically rotate and output an image of the object 200 by physically rotating around the optical axis of the rotating optical system, which is the optical axis of the rotating optical system 110. The type of rotating optical system 110 is not particularly limited, and examples include a Dove prism, an Abbe-Koenig prism, a combination of multiple mirrors, and an acousto-optical Dove prism. In this embodiment, a Dove prism is used as the rotating optical system 110. A Dove prism is composed of a single rigid body, is robust against physical rotation, and allows for easy adjustment of the optical axis of the rotating optical system.

[0023] The first rotation device 121 (the same applies to the second rotation device 122) is a device that physically rotates the rotating optical system 110 to optically rotate the image. The type of first rotation device 121 is not particularly limited, and examples include a device that rotates the rotating optical system 110 using a belt drive mechanism, a gear mechanism, or the like. In the case of this embodiment, the first rotation device 121 is a hollow motor, and includes a rotating member 123, a fixed member 124, and a holder 125.

[0024] Rotating member 123 is a cylindrical member that holds rotating optical system 110 therein via holder 125 and rotates together with rotating optical system 110 around the optical axis of the rotating optical system. In this embodiment, first rotating device 121 is a servo motor, and a magnet (not shown) is attached to the outer periphery of rotating member 123.

[0025] In the direction of the rotation axis of the first rotating device 121, the rotating member 123 is longer than the fixed member 124, and both ends of the rotating member 123 protrude from both ends of the fixed member 124. Both ends of the rotating member 123 protruding from the fixed member 124 are provided with screw holes 126 that penetrate radially and are arranged side by side in the circumferential direction.

[0026] Set screws 129, which are screws that contact the outer peripheral surface of holder 125, are threaded into the screw holes 126. The set screws 129 are members that generate a force that tightens the rotating optical system 110 via holder 125 and holds it within fixed member 124, and by changing the tightening force of the multiple set screws 129, it is possible to fine-tune the parallelism and degree of coincidence between the optical axis of the rotating optical system 110 and the rotation axis of first rotation device 121. In other words, the screw holes 126 provided in the rotating member 123 and the set screws 129 that thread into the screw holes 126 adjust the position and attitude of holder 125 housed within rotating member 123 relative to the rotating member 123, thereby adjusting the relationship in position and attitude between the optical axis of the rotating optical system 110 and the rotation axis of first rotation device 121, and function as an adjustment and attachment means that integrates the rotating member 123 and the rotating optical system 110 via holder 125.

[0027] Furthermore, a polymeric sheet (not shown) is disposed between the holder 125 and the rotating member 123 on the side of the holder 125 opposite the set screw 129, which is the adjustment attachment means, in the direction in which force is generated by the set screw 129. The polymeric sheet is, for example, paper, a resin sheet, or a resin film, and preferably has a thickness of 250 μm or less. This makes it possible to disperse stress when the set screw 129 is tightened, and also improves the stability when the rotating optical system 110 is rotated. In particular, these effects can be enhanced by sandwiching a sheet of about 10 μm.

[0028] When a Dove prism is used as the rotating optical system 110, the first rotating device 121 is set so that the rotation speed of the first rotating device 121 is half the rotation speed of the object 200. This is because the optical rotation of the image in a Dove prism is twice as large as the physical rotation of the image itself.

[0029] Fixed member 124 is a member that rotatably holds rotating member 123. In the present embodiment, fixed member 124 is a housing of a hollow motor that is first rotating device 121, and is attached to base 128 via bracket 127.

[0030] There are no limitations on the structure or shape of the base 128. In the present embodiment, the base 128 holds the first rotation device 121, the second rotation device 122, the first imaging device 201, and the second imaging device 202. By attaching the first rotation device 121, the second rotation device 122, the first imaging device 201, and the second imaging device 202 to the base 128, they are arranged so that a first optical axis 101, which is the optical axis of the first rotation device 121, and a second optical axis 102, which is the optical axis of the second rotation device 122, intersect at one point.

[0031] The first adapter 131 (similar to the second adapter 132) has a mechanism for connecting the first imaging device 201 and the first rotating device 121 so that the imaging optical axis of the first imaging device 201, which captures an image that rotates optically due to the physical rotation of the rotating optical system 110, coincides with the rotation axis of the first rotating device 121, and is equipped with an imaging side member 133, a rotating side member 134, and a bearing 135.

[0032] The imaging side member 133 is an annular member fixed to the first imaging device 201. The manner in which the imaging side member 133 is fixed to the first imaging device 201 is not particularly limited, but in this embodiment, the imaging side member 133 is fixed to the first imaging device 201 by rotating around the rotation axis of the first rotation device 121 relative to the rotation-side member 134 via a bearing 135. Specifically, a female screw having a diameter sufficient to surround a lens or the like is provided on the distal end surface of the first imaging optical system 203 of the first imaging device 201, and a male screw that screws into the female screw of the first imaging optical system 203 is provided on the distal end of the imaging side member 133 on the first imaging device 201 side. Even when the first adapter 131 is fixed to the first rotation device 121, the imaging side member 133 can rotate via the bearing 135, and the male screw of the imaging side member 133 can be rotated and screwed into the female screw of the first imaging optical system 203 to connect and fix the imaging side member 133 to the first imaging optical system 203.

[0033] If the diameter of the female screw of the first imaging optical system 203 does not match the diameter of the male screw of the imaging side member 133, a diameter conversion member (not shown) may be provided that integrally includes a first member having a diameter that can be attached to the male screw of the imaging side member 133 and a second member having a diameter different from that of the first member that can be attached to the female screw of the first imaging optical system 203 of the first imaging device 201. This allows the stereoscopic image imaging system 100 to be flexibly applied to multiple first imaging devices 201.

[0034] The rotation-side member 134 is an annular member fixed to the first rotation device 121. The manner in which the rotation-side member 134 is fixed to the first rotation device 121 is not particularly limited, but in the present embodiment, the rotation-side member 134 has a generally cylindrical shape in overall view, and is fixed to the end surface of the fixed member 124 of the first rotation device 121 on the first imaging device 201 side. By fixing the rotation-side member 134 to the fixed member 124, the rotation axis of the first rotation device 121 and the tube axis of the rotation-side member 134 coincide with each other. The manner in which the rotation-side member 134 is fixed to the fixed member 124 is not particularly limited, but in the present embodiment, a hole penetrating the first rotation device 121 parallel to the tube axis is provided, and a screw hole is provided in the end surface of the fixed member 124 at a position corresponding to the hole, and the first rotation device 121 and the fixed member 124 are fastened and fixed with a bolt. Note that the first rotation device 121 and the rotation-side member 134 may each be provided with an engagement structure so that the rotation axis of the first rotation device 121 coincides with the tube axis of the rotation-side member 134. An example of an engagement structure is a structure in which multiple pins are provided on one side and pin holes into which the pins are inserted are provided on the other side.

[0035] In this embodiment, the rotating-side member 134 includes through-holes 136 that extend from the fixed member 124 of the rotating member 123 to the adjustment attachment means (screw holes 126 and set screws 129) provided on the portion that protrudes when inserted into the first adapter 131. The through-holes 136 are used to insert an adjustment tool for adjusting the adjustment attachment means, such as a hexagonal wrench capable of rotating the set screws 129. The through-holes 136 penetrate the peripheral wall of the cylindrical rotating-side member 134 in the radial direction. The shape of the through-holes 136 is not particularly limited, and any shape can be used, such as a cylindrical shape surrounded by a periphery or a notched shape as in this embodiment. The number of through-holes 136 is not particularly limited, but providing through-holes 136 at multiple locations in the circumferential direction makes it easier to access the adjustment attachment means without changing the position at which the rotating member 123 is stopped.

[0036] The bearing 135 connects the annular (cylindrical) imaging side member 133 and the annular (cylindrical) rotation side member 134 so as to be capable of relative rotation. The type of bearing 135 is not particularly limited, and may be either a plain bearing 135 or a rolling bearing 135. In the present embodiment, a ball bearing is used as the bearing 135. With the bearing 135, in a state in which the rotation side member 134 is fixed to the fixed member 124 of the first rotation device 121, the imaging side member 133 can be screwed and fixed to the first imaging optical system 203 of the first imaging device 201 while maintaining the tube axis of the imaging side member 133 and the tube axis of the rotation side member 134 coaxially.

[0037] According to the first adapter 131 and the first rotation device 121 including the first adapter 131 according to the above embodiment, the first imaging device 201 and the first rotation device 121 can be easily connected with each other in a state where the rotation axis of the first rotation device 121 is aligned with the imaging optical axis of the first imaging device 201. Therefore, it is possible to significantly reduce the time spent on adjustment work for aligning the rotation axis of the first rotation device 121 with the imaging optical axis of the first imaging device 201. The same applies to the second adapter 132 and the second rotation device 122.

[0038] Furthermore, since the rotation axis of the first rotation device 121 and the optical axis of the rotating optical system 110 can be aligned on the assumption that the rotation axis of the first rotation device 121 and the imaging optical axis of the first imaging device 201 are aligned, the time required for the alignment can also be shortened.

[0039] Furthermore, since it is assumed that the rotation axis of the first rotating device 121 and the imaging optical axis of the first imaging device 201 are aligned, the axis alignment work can be performed without rotating the rotating optical system 110, which simplifies the work required for axis alignment and reduces the time required.

[0040] Furthermore, the through-hole 136 provided in the rotating side member 134 makes it easy to align the rotation axis of the first rotating device 121 with the optical axis of the rotating optical system 110, thereby further shortening the time required for axial alignment.

[0041] Furthermore, by placing a sheet made of a polymeric material such as paper on the portion where force is applied by the adjusting and mounting means, the position and attitude of rotating optical system 110 can be effectively adjusted with respect to the rotation axis of first rotating device 121, and it is possible to prevent damage to rotating optical system 110 due to force received from the adjusting and mounting means. Also, rotating optical system 110 can be rotated in a stable state.

[0042] 4 is a block diagram showing the functional configuration of the control device 150. The control device 150 is a device including a processor that controls each of the first rotation device 121 and the second rotation device 122. The control device 150 causes the processor to execute a stereoscopic image capturing program, thereby realizing a rotation angle control unit 151, an angle acquisition unit 152, an image acquisition unit 153, and a stereoscopic image derivation unit 154. In the present embodiment, the control device 150 realizes a flow velocity derivation unit 155 and a correction value group derivation unit 156 by the stereoscopic image capturing program.

[0043] The rotation angle control unit 151 controls the first rotation device 121 and the second rotation device 122 to rotate the rotating optical system 110 held by each rotating member 123 at a predetermined rotation angle. In the present embodiment, a Dove prism is used as the rotating optical system 110, and therefore the rotation speeds of the first rotation device 121 and the second rotation device 122 are controlled to be half the rotation speed of the target object 200. In the present embodiment, the rotation angle control unit 151 controls the first rotation device 121 and the second rotation device 122 so that the phase of the rotating optical system 110 of the first rotation device 121 matches the phase of the rotating optical system of the second rotation device 122. Furthermore, when acquiring a correction value (details will be described later), the rotation angle control unit 151 controls the rotating optical system 110 to rotate by a predetermined angle and then stop.

[0044] The angle acquisition unit 152 acquires a first angle θ1, which is the angle of the first optical axis 101 relative to the rotation axis 103 of the object 200, and a second angle θ2, which is the angle of the second optical axis 102 relative to the rotation axis 103. The method of acquiring the first angle θ1 and the second angle θ2 is not limited. In the present embodiment, the control device 150 includes a user interface, and the angle acquisition unit 152 acquires the first angle θ1 and the second angle θ2, which are measured when the stereoscopic imaging system 100 is installed, via the user interface.

[0045] The image acquisition unit 153 acquires a first rotated image from the first imaging device 201, which captures the first rotated image by the first rotation device 121, and acquires a second rotated image from the second imaging device 202, which captures the second rotated image by the second rotation device 122. In the present embodiment, the image acquisition unit 153 controls the first imaging device 201 and the second imaging device 202 so that the imaging timings are synchronized. The imaging frame rates of the first imaging device 201 and the second imaging device 202 are set to the same. When acquiring a correction value (details will be described later), the image acquisition unit 153 controls each imaging device to acquire at least one image when the rotation angle control unit 151 acquires stillness information indicating that the rotating optical system 110 has been stopped.

[0046] The stereoscopic image derivation unit 154 performs coordinate transformation on the first object image based on the first object image, which is a rotated image of the object 200 acquired by the image acquisition unit 153, and a first corrected image (details will be described later) acquired in advance, and converts the distortion of the first object image captured obliquely with respect to the rotation axis 103 into a first normal image, which is a normal image. Similarly, the second object image is converted into a second normal image, which is a normal image, using the first corrected image. Note that the normal image is an image similar to an image captured from the front of the object 200. The stereoscopic image derivation unit 154 derives a static stereoscopic image of the object 200 using the first normal image, the second normal image, the first angle θ1, and the second angle θ2.

[0047] The flow velocity derivation unit 155 derives multiple velocity components of the flow field based on the 3D image derived by the 3D image derivation unit 154. For example, the flow velocity derivation unit 155 derives multiple velocity components of the flow field by performing PIV (Particle Image Velocimetry) analysis using multiple first normal images and multiple second normal images obtained at a predetermined frame rate. Specifically, it is possible to calculate the three-dimensional velocity components U, V, and W at any position on the measurement cross section, and further to calculate the two-dimensional three-component velocity distribution on the two-dimensional measurement cross section.

[0048] The correction value group derivation unit 156 derives a first correction value group from a first correction image acquired in advance by the stereoscopic imaging system 100 using a calibration target, derives a second correction value group from the second correction image, and stores them in the storage device 157. This allows the stereoscopic image derivation unit 154 to derive a stationary stereoscopic image of the rotating object 200 based on the stored first correction value group and second correction value group.

[0049] FIG. 5 is a perspective view showing a state in which a corrected image is being acquired by the stereoscopic imaging system 100. FIG. 6 is a flowchart showing the flow of acquiring a corrected image. As shown in FIG. 5, the stereoscopic imaging system 100, the imaging device, and the calibration target 210 are arranged in the same position as when acquiring a stereoscopic image of the object 200 (S101). Next, the rotation angle control unit 151 controls each image rotation device to rotate the rotating optical system 110 by a predetermined angle and then stop it (S102). For example, the rotation angle control unit 151 rotates the rotating optical system 110 by 0.1 degrees and then stops it. The image acquisition unit 153 controls each imaging device to acquire a first corrected image and a second corrected image (S103). If the rotating optical system 110 is a Dove prism, the rotation, stop, and image acquisition are repeated until the Dove prism is rotated 180 degrees (S104, Yes). Next, the correction value group derivation unit 156 derives a correction value group for each feature point (e.g., each intersection) of the calibration target 210 for each of the obtained corrected images, and stores the group in the storage device 157 (S105). As described above, a correction value group is derived for each rotation angle of the rotating optical system 110, and each correction value group is stored together with the value at which the rotating optical system 110 has rotated and the first angle θ1 or the second angle θ2.

[0050] 7 is a flowchart showing the flow of acquiring a stereoscopic image of the object 200. The stereoscopic image capturing system 100, the imaging device, and the object 200 are arranged so as to be the same as the arrangement for capturing the calibration target 210 (S201). Note that the object 200 may be imaged first, and then the calibration target 210 may be imaged. Next, the rotation angle control unit 151 controls each image rotation device to rotate the rotating optical system 110 in synchronization with the rotation of the object 200 (S202). The image acquisition unit 153 acquires a first object image and a second object image at a predetermined frame rate (S203). The imaging continues for a predetermined time (S204, No). After a predetermined time has elapsed (S204, Yes), the stereoscopic image derivation unit 154 derives a first normal image and a second normal image for each obtained object image using a group of correction values ​​corresponding to the angle derived from the frame rate and the rotation speed of the rotating optical system 110, and derives a stationary stereoscopic image of the object 200 using the first angle θ1 and the second angle θ2 (S205).

[0051] The present invention is not limited to the above-described embodiments. For example, the present invention may be embodied in another embodiment by arbitrarily combining the components described in this specification or by excluding some of the components. Furthermore, the present invention also includes various modifications that would occur to a person skilled in the art without departing from the spirit of the present invention, i.e., the meaning of the wording of the claims.

[0052] For example, it is desirable to be able to synchronously control the rotation speed of the object 200 and the two image rotation devices, but if the rotation speeds of the two image rotation devices are set separately and the object 200 in the resulting object image is stationary, a three-dimensional image of the object 200 can be obtained.

[0053] Furthermore, although the case where there are two pairs of imaging devices and image rotation devices has been described, the stereoscopic image imaging system 100 may include three or more pairs of imaging devices and image rotation devices.

[0054] Furthermore, among the multiple pairs of imaging devices and image rotation devices, the first angle θ1 of the pair of the first imaging device 201 and the first rotation device 121 may be set to 0 degrees.

[0055] Furthermore, although the calibration target 210 has been described as having a checkered pattern, the pattern of the calibration target 210 is not limited to this, and it may be, for example, a pattern of aligned dots.

[0056] Furthermore, the object 200 is not limited to a rigid body, but may be a fluid, a combination of a rigid body and a fluid, or the like.

[0057] (summary) The stereoscopic imaging system 100 of the first embodiment includes a first rotation device 121 and a second rotation device 122, which are image rotation devices that rotate a rotational optical system 110 to rotate an image, and a control device 150 that controls the first rotation device 121 and the second rotation device 122, which are arranged so that a first optical axis 101 that is the optical axis of the first rotation device 121 and a second optical axis 102 that is the optical axis of the second rotation device 122 intersect at one point. The control device 150 includes a rotation angle control unit 151 that rotates the rotational optical system 110 by a predetermined rotation angle, an angle acquisition unit 152 that acquires a first angle θ1 that is the angle of the first optical axis 101 with respect to a rotation axis 103 of a rotating object 200, and a second angle θ2 that is the angle of the second optical axis 102 with respect to the rotation axis 103, and and an image acquisition unit 153 that acquires a first rotated image from a first imaging device 201 that captures a first rotated image by the second rotation device 122 and acquires a second rotated image from a second imaging device 202 that captures a second rotated image by the second rotation device 122; and a stereoscopic image derivation unit 154 that derives a stationary stereoscopic image of the rotating object 200 based on a first corrected image, which is the first rotated image obtained by imaging the calibration target at a predetermined rotation angle, and a second corrected image, which is the second rotated image, a first object image, which is the first rotated image obtained by imaging the rotating object 200 at a predetermined frame rate, and a second object image, which is the second rotated image, the first object image corresponding to the rotation angle at which the first corrected image was captured, and the first object image corresponding to the rotation angle at which the second corrected image was captured, and a first angle θ1 and a second angle θ2.

[0058] According to the first aspect, it is possible to capture a three-dimensional image of an object 200, such as a propeller rotating at high speed or an impeller inside a pump, in a relatively stationary state. Furthermore, it is possible to capture a blur-free three-dimensional image of an extremely slow relative flow of a fluid, such as air or liquid, around the object 200, excluding the swirling component that accompanies the rotation of the object 200.

[0059] The stereoscopic imaging system 100 of the second embodiment includes the system of the first embodiment, and includes a flow velocity derivation unit 155 that derives a plurality of velocity components of a flow field based on the stereoscopic image derived by the stereoscopic image derivation unit 154.

[0060] According to the second aspect, it is possible to measure the influence of the shape of a rotating rigid body on the surrounding fluid, etc., using the measured three-dimensional velocity components.

[0061] The third embodiment of the stereoscopic imaging system 100 includes the first embodiment or the second embodiment, and the control device 150 includes a correction value group derivation unit 156 that derives a first group of correction values ​​from the first correction image and a second group of correction values ​​from the second correction image and stores them in a memory device 157, and the stereoscopic image derivation unit 154 derives a stationary stereoscopic image of the rotating object 200 based on the stored first and second correction value groups.

[0062] According to the third aspect, when capturing images of a plurality of objects 200 in the same arrangement, a stereoscopic image can be efficiently derived using a group of correction values.

[0063] The stereoscopic imaging system 100 of the fourth embodiment includes the second embodiment, and the first angle θ1 is 0 degrees.

[0064] The stereoscopic image capturing method of the fifth aspect is a stereoscopic image capturing method implemented on a first rotation device 121 and a second rotation device 122, which are image rotating devices that rotate a rotation optical system 110 to rotate an image, and which are arranged so that a first optical axis 101 that is the optical axis of the first rotation device 121 and a second optical axis 102 that is the optical axis of the second rotation device 122 intersect at one point, in which a rotation angle control unit 151 rotates the rotation optical system 110 at a predetermined rotation angle, and an angle acquisition unit 152 acquires a first angle θ1 that is the angle of the first optical axis 101 with respect to a rotation axis 103 of a rotating object 200 and a second angle θ2 that is the angle of the second optical axis 102 with respect to the rotation axis 103, and The image acquisition unit 153 acquires a first rotated image from the first imaging device 201 that captures the rotated image, and the image acquisition unit 153 acquires a second rotated image from the second imaging device 202 that captures the second rotated image by the second rotation device 122. The image acquisition unit 154 derives a static three-dimensional image of the rotating object 200 based on a first corrected image which is the first rotated image captured by capturing the calibration target at a predetermined rotation angle, and a second corrected image which is the second rotated image, a first object image which is the first rotated image captured by capturing the rotating object 200 at a predetermined frame rate, and a second object image which is the second rotated image, the first object image corresponding to the rotation angle at which the first corrected image was captured, and the first object image corresponding to the rotation angle at which the second corrected image was captured, and the first angle θ1 and the second angle θ2.

[0065] According to the fifth aspect, it is possible to three-dimensionally capture images of a target object 200, such as a propeller rotating at high speed or an impeller inside a pump, in a relatively stationary state. Furthermore, it is possible to capture an extremely slow relative flow of a fluid, such as air or liquid, around the target object 200, excluding the swirling component that accompanies the rotation of the target object 200, as a blur-free three-dimensional image.

[0066] The stereoscopic image capturing program of the sixth aspect is a stereoscopic image capturing method implemented on a first rotation device 121 and a second rotation device 122, which are image rotating devices that rotate a rotating optical system 110 to rotate an image, and which are arranged so that a first optical axis 101 that is the optical axis of the first rotation device 121 and a second optical axis 102 that is the optical axis of the second rotation device 122 intersect at one point, in which a rotation angle control unit 151 rotates the rotating optical system 110 at a predetermined rotation angle, and an angle acquisition unit 152 acquires a first angle θ1 that is the angle of the first optical axis 101 with respect to a rotation axis 103 of a rotating object 200, and a second angle θ2 that is the angle of the second optical axis 102 with respect to the rotation axis 103, and The processor is caused to execute a stereoscopic image capturing method in which a first rotated image is acquired from one imaging device 201, and a second rotated image is acquired by an image capturing unit 153 from a second imaging device 202 that captures a second rotated image by a second rotation device 122, and a stereoscopic image derivation unit 154 derives a still stereoscopic image of the rotating object 200 based on a first corrected image which is the first rotated image captured by capturing a calibration target at a predetermined rotation angle, and a second corrected image which is the second rotated image, a first object image which is the first rotated image captured by capturing a rotating object 200 at a predetermined frame rate, and a second object image which is the second rotated image, the first object image corresponding to the rotation angle at which the first corrected image was captured, and the first object image corresponding to the rotation angle at which the second corrected image was captured, and a first angle θ1 and a second angle θ2.

[0067] According to the sixth aspect, it is possible to capture a three-dimensional image of a target object 200, such as a propeller rotating at high speed or an impeller inside a pump, in a relatively stationary state. Furthermore, it is possible to capture a blur-free three-dimensional image of an extremely slow relative flow of a fluid, such as air or liquid, around the target object 200, excluding the swirling component that accompanies the rotation of the target object 200. [Industrial Applicability]

[0068] The present invention can be used to study the state of a rotating rigid body, the state of a fluid passing through a flow path in a rotating manner, an engine for monitoring the fluid around a rotating rigid body, and the relationship between the shape of a rotating rigid body and the fluid. [Explanation of symbols]

[0069] 100 Stereoscopic Imaging System 101 First optical axis 102 Second optical axis 103 Rotation axis 110 Rotating Optical System 121 First Rotating Device 122 Second Rotating Device 123 Rotating Members 124 Fixing member 125 holder 126 screw hole 127 Bracket 128 Foundation 129 Grub Screw 131 First Adapter 132 Second Adapter 133 Imaging side component 134 Rotating member 135 bearings 136 Penetration 150 control device 151 Rotation angle control unit 152 Angle acquisition part 153 Image acquisition section 154 Stereo image derivation part 155 Flow velocity derivation part 156 Correction value group derivation unit 157 Storage device 200 objects 201 First Imaging Device 202 Second Imaging Device 203 First Imaging Optical System 210 Calibration Target

Claims

1. a first rotation device and a second rotation device, which are image rotation devices that rotate the rotation optical system to rotate the image; a control device that controls the first rotation device and the second rotation device, each of which is arranged so that a first optical axis that is an optical axis of the first rotation device and a second optical axis that is an optical axis of the second rotation device intersect at one point; The control device a rotation angle control unit that rotates each of the rotation optical systems by a predetermined rotation angle; an angle acquisition unit that acquires a first angle that is an angle of the first optical axis with respect to a rotation axis of a rotating object, and a second angle that is an angle of the second optical axis with respect to the rotation axis; an image acquisition unit that acquires a first rotated image from a first imaging device that captures a first rotated image by the first rotation device, and acquires a second rotated image from a second imaging device that captures a second rotated image by the second rotation device; a first corrected image, which is a first rotated image obtained by capturing an image of a calibration target at a predetermined rotation angle, and a second corrected image, which is a second rotated image; a first object image, which is a first rotated image obtained by capturing an image of a rotating object at a predetermined frame rate, and a second object image, which is a second rotated image; the first object image corresponding to the rotation angle at which the first corrected image was captured and the first object image corresponding to the rotation angle at which the second corrected image was captured; and a stereoscopic image derivation unit that derives a static stereoscopic image of the rotating object based on the first angle and the second angle; A stereoscopic imaging system comprising:

2. a flow velocity derivation unit that derives a plurality of velocity components of a flow field based on the stereoscopic image derived by the stereoscopic image derivation unit; The stereoscopic imaging system according to claim 1 , comprising:

3. The control device a correction value group derivation unit that derives a first correction value group from the first correction image and a second correction value group from the second correction image, and stores the first and second correction value groups in a storage device; The stereoscopic image deriving unit Deriving a stationary stereoscopic image of the rotating object based on the stored first correction value group and the stored second correction value group.

3. The stereoscopic imaging system according to claim 1.

4. The first angle is 0 degrees. The stereoscopic imaging system according to claim 2 .

5. A stereoscopic image capturing method is performed on a first rotation device and a second rotation device, which are image rotation devices that rotate a rotational optical system to rotate an image, and the first rotation device and the second rotation device are arranged so that a first optical axis that is an optical axis of the first rotation device and a second optical axis that is an optical axis of the second rotation device intersect at one point, a rotation angle control unit that rotates the rotation optical system by a predetermined rotation angle; an angle acquisition unit acquires a first angle that is an angle of the first optical axis with respect to a rotation axis of a rotating object, and a second angle that is an angle of the second optical axis with respect to the rotation axis; an image acquisition unit acquires a first rotated image from a first imaging device that captures a first rotated image by the first rotation device, and acquires a second rotated image from a second imaging device that captures a second rotated image by the second rotation device; A first corrected image, which is a first rotated image obtained by capturing an image of the calibration target at a predetermined rotation angle, and a second corrected image, which is a second rotated image, and a first object image, which is a first rotated image obtained by capturing an image of a rotating object at a predetermined frame rate, and a second object image, which is a second rotated image, the first object image corresponding to the rotation angle at which the first corrected image was captured and the first object image corresponding to the rotation angle at which the second corrected image was captured, and a still three-dimensional image of the object rotating based on the first angle and the second angle. Stereoscopic imaging method.

6. A method for causing a processor to execute the stereoscopic image capturing method according to claim 5. Stereoscopic imaging program.

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