JPWO2019216297A1 - Calibration device and calibration method - Google Patents

Abstract

In order to provide a technique for reducing the burden of work related to calibration, the calibration device 80 includes a support member 81 and a calibration member 82. The calibration member 82 is a member having a detection target point used for calibrating the photographing apparatus. The support member 81 includes a configuration that supports the calibration member 82 in a displaceable state in a perspective direction in which the calibration member 82 approaches or moves away from the photographing device for photographing the calibration member 82.

Description

The present invention relates to a technique relating to calibration of a photographing apparatus.

The photographing device includes what is called a stereo camera or a 3D (Dimensions) camera. Such an imaging device has a configuration capable of generating a stereoscopic photograph by having a plurality of imaging units and simultaneously photographing an object from a plurality of different directions to realize binocular parallax. The photographing device can output not only information related to the length of the subject in the vertical direction and the horizontal direction in the captured image, but also information related to the length of the subject in the depth direction of the captured image.

By the way, the image captured by the photographing device is distorted due to different focal lengths, center position deviations, lens distortions, and the like for each lens. The image distortion correction function provided in the photographing device or the information processing device is a function for correcting the distortion of such a photographed image. For example, the distortion correction parameters used in the processing by this distortion correction function are obtained in advance by calibration (calibration processing).

Non-Patent Document 1 shows an example of calibration using a flat board. In the calibration in Non-Patent Document 1, for example, an operator photographs a two-dimensional pattern drawn on the flat board while changing the inclination and position of the flat board by the imaging device to be calibrated. Then, for example, distortion correction parameters are calculated by the information processing device using the captured two-dimensional pattern.

Zhengyou Zhang, "A flexible new technique for camera calibration", IEEE Transactions on Pattern Analysis and Machine Intelligence, 2000, Vol. 22 (11), p.1330-1334

By the way, there is a case where the area to be monitored and the object to be observed are observed (monitored) by using the image taken by the photographing device. In such a case, when information such as the size of the object shown in the captured image is acquired from the captured image, in order to improve the reliability of the acquired information, the size of the monitoring target area and the observation target It is preferable to calibrate the photographing apparatus for a spatial area having a size corresponding to the size of the object.

However, there arises a problem that the burden on the operator performing the calibration increases as the size of the space area to be calibrated increases. For example, when the calibration method shown in Non-Patent Document 1 is adopted, there is an operation of moving a flat board used for calibration. When the flat board becomes large according to the size of the space area to be calibrated, the work load of changing the inclination and the position of the flat board increases due to the size and weight of the flat board. In particular, when the area to be calibrated is underwater due to the presence of the object to be observed in water, the burden on the operator becomes large. For example, when the area to be calibrated is underwater, it is conceivable that the operator operates the underwater flat board from the ship. In this case, the scaffolding of the worker is poor and the posture of the worker tends to be unstable. In addition, when the flat board becomes large, the water pressure received by the flat board increases and the work load of operating the flat board increases. To do.

The present invention has been made to solve the above problems. That is, a main object of the present invention is to provide a technique capable of reducing the burden of work related to calibration.

In order to achieve the above object, the calibrator of the present invention
A calibration member with a detection target point used for calibration of the imaging device,
A support member for supporting the calibration member in a displaceable state in a perspective direction approaching or moving away from the imaging device for photographing the calibration member is provided.

Moreover, the calibration method of the present invention
A calibration member having a detection target point used for calibrating the imaging device is supported by the support member in a state of being displaceable in the perspective direction toward or away from the imaging device.
While the calibration member is displaced, the calibration member is photographed by the imaging device, and the calibration member is photographed.
The detection target point is detected from the captured image of the calibration member by the imaging device, and the imaging device is calibrated using the detected detection target point.

According to the present invention, it is possible to reduce the burden of work related to calibration.

It is a figure explaining the structure of the calibration apparatus of 1st Embodiment which concerns on this invention. It is a figure explaining the installation example of the calibration apparatus of 1st Embodiment. It is a figure explaining one structural example of the installation member which constitutes the calibration apparatus of 1st Embodiment. It is a figure explaining the rotational displacement of a flat board which is a calibration member in 1st Embodiment. It is a figure explaining the plane method which is one of the calibration methods. It is a figure explaining the work of photographing a flat board in the calibration using the calibration apparatus of 1st Embodiment. It is a figure explaining one aspect example of a cage frame. It is a figure explaining another example of an aspect of a cage frame. It is a figure explaining the configuration example which attaches the installation member constituting the calibration apparatus of 1st Embodiment to a cage frame. It is a figure explaining the modification of the calibration apparatus shown in FIG. It is a figure explaining the effect when a calibrator has a structure in which a support member supporting a flat board is rotatable with respect to an installation member. It is a figure explaining the structure of the calibration apparatus of 2nd Embodiment which concerns on this invention. It is a figure explaining the work of photographing a flat board in the calibration using the calibration apparatus of 2nd Embodiment. It is a figure explaining one embodiment example when the calibration apparatus of 2nd Embodiment is used for calibration by the DLT (Direct Linear Transformation) method. It is a figure explaining the structure of the calibration apparatus of another embodiment which concerns on this invention.

Hereinafter, embodiments according to the present invention will be described with reference to the drawings.

<First Embodiment>
FIG. 1 shows an example of the calibration device of the first embodiment according to the present invention together with the photographing device. The calibration device 10 of the first embodiment is a device used for underwater photographing of the calibration member (flat board 13) in the calibration of the photographing device 11. Further, in the example of FIG. 1, the photographing device 11 has a frame in which two cameras (photographing units) 15 and 16 are arranged side by side with an interval (for example, a baseline length of 0.3 to 0.9 meters). It has a structure fixed to a member or the like. With such a configuration, the photographing device 11 has a function capable of generating a stereoscopic photograph by simultaneously photographing an object from a plurality of different directions and thereby realizing binocular parallax. The cameras 15 and 16 constituting the photographing device 11 have a function of photographing a moving image or a still image, and the lenses provided in the cameras 15 and 16 are oriented in the same direction.

The calibration device 10 of the first embodiment is configured on the assumption that the photographing device 11 is calibrated by a calibration method using a flat board (hereinafter, also referred to as a flat method). That is, the calibration device 10 of the first embodiment includes a photographing device fixing member 12 which is a device fixing portion for fixing the photographing device 11, a flat board 13 which is a calibration member, and a support member 14 which supports the flat board 13. It has.

The flat board 13 is a calibration member photographed by the imaging device 11 for calibration of the imaging device 11, and a pattern (two-dimensional pattern) including a detection target point used for calibration is formed on the surface of the flat board 13. There is. The pattern formed on the flat board 13 (hereinafter, also referred to as a calibration pattern) is a pattern in which a predetermined detection target point can be easily recognized from the captured image. For example, the calibration pattern includes a checker (checkerboard pattern) pattern and a pattern in which round and square dots are arranged at intervals from each other.

Further, the flat board 13 has a size in consideration of the size of the area to be calibrated. For example, when the size of the area to be calibrated is about 1 meter in length, 1 meter in width, and 3 meters in depth, the flat board 13 has a size of 1 meter in length and 0.7 meters in width. Has. Further, the thickness (for example, about 1 mm) and the material (for example, a metal such as aluminum or a resin material) of the flat board 13 are set in consideration of weight reduction and mechanical strength.

Instead of the flat board 13 having the above configuration, the flat board 13 having the following configuration may be adopted. For example, a sheet (cloth sheet, resin sheet, metal sheet, etc.) on which a calibration pattern is formed may be adopted as the flat board 13 having a structure in which the sheet is stretched inside the frame. In this case, the weight of the flat board 13 can be reduced. However, depending on the usage environment, there may be concerns about weak mechanical strength and distortion of the sheet (calibration pattern). Such a reinforcing material may be formed. Further, instead of the structure in which the sheet is stretched inside the frame, a structure in which the rod members are arranged in a grid pattern inside the frame may be adopted as the flat board 13. In this case, for example, the bars arranged in a grid pattern form a calibration pattern, and the intersections of the bars in a grid pattern are set as detection target points used for calibration.

In the plane method using the plane board 13 as described above, as shown in the image diagram of FIG. 5, the plane board 13 is moved by the photographing device 11 while changing the inclination and the position of the plane board 13 with respect to the photographing device 11. The calibration pattern is photographed. Then, a predetermined detection target point in the plurality of captured images captured in this way is detected (extracted) by, for example, a computer (information processing device). Further, using the position of the detection target point in the captured image, a plurality of set parameters such as the distortion correction parameter used in the distortion correction processing of the captured image are calculated by the computer. Furthermore, a computer calculates a conversion matrix of 2D coordinates and 3D coordinates for converting 2D (Dimensions) coordinates in a captured image into 3D (Dimensions) coordinates using these parameters. Here, the distortion correction parameter and the calculation method of the conversion matrix of the 2D coordinate and the 3D coordinate are not particularly limited, and the description thereof will be omitted.

As shown in FIG. 1, the photographing device fixing member 12 has a support column member 18. The photographing device 11 is fixed to the support member 18 by, for example, spiral fastening. Further, an installation member 19 is provided on one end side of the support column member 18. As shown in FIG. 2, the installation member 19 has a configuration that allows the support column member 18 to be attached to the edge 20A of the ship 20. The installation member 19 is a member that enables the photographing device 11 to be suspended out of the ship and placed in water by the support member 18 by attaching the support member 18 to the edge 20A of the ship 20. The configuration of the installation member 19 is not particularly limited as long as the support column member 18 can be installed on the edge 20A of the ship 20, but there is a configuration as shown in FIG. 3, for example.

FIG. 3 is a diagram showing an example of the configuration of the installation member 19 in a state of being installed on the edge 20A of the ship 20 by a cross section. In the example of FIG. 3, the installation member 19 includes a fitting portion 22 and a claw portion 23. The fitting portion 22 has an aspect of fitting with the edge 20A of the ship 20. The claw portion 23 is a portion that functions as a hook portion that is inside the ship 20 and that locks on a rod-shaped member (for example, a rod made of stainless steel) 21 that extends along the edge 20A of the ship 20. That is, the installation member 19 shown in FIG. 3 is a member for hooking and installing the photographing device 11 on the edge 20A of the ship 20 via the support column member 18. Further, when the installation member 19 has the configuration as shown in FIG. 3, the rod-shaped member 21 functions as a locking receiving portion for locking the claw portion (hooking portion) 23 as described above.

Further, the installation member 19 may have the following configuration. For example, when it is assumed that it is difficult to hook and install the installation member 19 on the edge 20A of the ship 20, the installation member 19 includes a pedestal (weight) to be installed on the deck of the ship 20, and the pedestal and support. It may be configured to have a connecting member for connecting the member 18.

The support member 14 is a support member that supports the flat board 13, which is a calibration member used in the calibration of the photographing apparatus 11, on the edge 20A of the ship 20. The support member 14 has a strut member 26 as shown in FIG. The support member 26 is provided with an installation member 27 on one end side thereof, and is provided with a mounting portion 28.

The installation member 27 has a configuration that can be arranged on the edge 20A of the ship 20 in a state of being displaceable in the perspective direction toward or away from the photographing device 11. For example, the installation member 27 has the same configuration as the installation member 19 of the photographing device fixing member 12.

The mounting portion 28 is a member for mounting the flat board 13 to the support column member 26, and includes, for example, a rotating shaft rod 30 and a rotating mechanism 31. In the example of FIG. 1, the rotary shaft rod 30 has a configuration in which it is connected to one side of a rectangular flat board 13. The rotating shaft rod 30 is connected to the support column member 26 via a rotating mechanism 31. The rotation mechanism 31 has a configuration in which the rotation shaft rod 30 is connected to the support column member 26 in a state in which the rotation shaft rod 30 can rotate around the central axis thereof. Here, the rotating shaft rod 30 is connected to the support column member 26 via the rotation mechanism 31 so that the direction along the central axis of the rotary shaft rod 30 and the direction along the central axis of the support column member 26 are orthogonal to each other.

As shown in FIG. 4, the mounting portion 28 having the above configuration can mount the flat board 13 on the support column member 26 in a state where the flat board 13 can be rotationally displaced about the central axis of the rotating shaft rod 30. ..

In the first embodiment, the rotary shaft rod 30 is provided with an operation unit 32 for operating the rotation of the rotary shaft rod 30 (in other words, the rotation of the flat board 13).

The support member 14 is configured as described above. The flat board 13 can be arranged in water by attaching the installation member 27 of the support member 14 to the edge 20A of the ship 20 and suspending the support member 26 outboard.

In the first embodiment, the photographing device fixing member 12 and the supporting member 14 have a positional relationship as shown in FIG. 4 when the photographing device 11 and the flat board 13 are installed on the ship 20, respectively. The orientation of the photographing device 11 and the flat board 13 is designed. That is, here, the direction in which the central axis of the rotational displacement of the flat board 13 extends is the Y direction, the side-by-side direction of the cameras 15 and 16 of the photographing device 11 is the X direction, and the flat board 13 approaches the photographing device 11. Alternatively, the perspective direction away from the distance is defined as the Z direction. The parallel directions of the cameras 15 and 16 of the photographing device 11 fixed to the photographing device fixing member 12 so that the Y direction, the X direction, and the Z direction are orthogonal to each other (including a substantially orthogonal relationship). The mounting angle between the support member 26 and the rotating shaft rod 30 in the support member 14, the height (hanging) position of the photographing device 11 and the flat board 13, and the like are appropriately designed.

The calibration device 10 of the first embodiment is configured as described above. The imaging work of the flat board 13 related to the calibration of the imaging device 11 using the calibration device 10 is performed as follows. For example, the photographing device 11 is placed in the water outside the ship by the operator hooking the photographing device fixing member 12 to which the photographing device 11 is fixed on the edge 20A of the ship 20. Further, the operator hooks the support member 14 to which the flat board 13 is attached on the edge 20A of the ship 20 and arranges the flat board 13 in the water outside the ship. In this way, the operator faces the photographing device 11 and the calibration pattern of the flat board 13 in water.

After that, for example, the flat board 13 is located at the P1 position (for example, the distance between the shooting device 11 and the flat board 13 is about 1 meter), which is a predetermined shooting position shown in FIG. 6, and the shooting device 11 is in operation (moving image). The operator rotates and displaces the flat board 13 using the operation unit 32 in a state of taking a picture or continuously taking a still image. After that, the operator changes the hooking position of the support member 14 on the edge 20A of the ship 20, and places the flat board 13 at the P2 position (for example, the distance between the shooting device 11 and the flat board 13) which is the predetermined next shooting position. Move to about 2 meters). Then, in the same manner as described above, the operator rotationally displaces the flat board 13 using the operation unit 32 while the photographing device 11 is operating.

In this way, the operator causes the photographing device 11 to take a picture of the calibration pattern of the flat board 13 while changing the position of the flat board 13 and the rotational displacement of the flat board 13.

After such a photographing operation, a predetermined detection target point is extracted from the calibration pattern in the captured image by, for example, a computer (information processing apparatus). Then, using the extracted detection target points, parameters such as distortion correction parameters are calculated by, for example, a computer. Further, a conversion matrix of 2D coordinates and 3D coordinates is calculated by, for example, a computer using the calculated parameters. Here, the method of the process of extracting the detection target point by the computer and the method of calculating the distortion correction parameter and the conversion matrix of the 2D coordinate and the 3D coordinate are not limited, and the description thereof will be omitted.

By providing the calibration device 10 of the first embodiment with the above configuration, it is possible to reduce the burden on the operator of the photographing work related to the calibration. That is, the calibration device 10 can be installed by hooking the photographing device 11 and the flat board 13 on the edge 20A of the ship 20. Therefore, by using the calibration device 10, the operator does not need to keep holding the photographing device 11 and the flat board 13 on a ship having a poor foothold during the imaging of the calibration. As a result, the calibration device 10 can reduce the burden on the operator. Further, since the calibration device 10 makes it possible for even one working vehicle to easily move the flat board 13, workability can be improved.

Further, since the calibration device 10 can support the flat board 13 on the edge 20A of the ship 20 during shooting for calibration, the size of the flat board 13 can be increased while suppressing an increase in the burden on the operator. It will be easy. As a result, the calibration device 10 can easily realize calibration corresponding to the expansion of the area to be calibrated.

Further, since the calibration device 10 has a simple structure, it is easy to carry.

By the way, in the first embodiment, the calibration device 10 is provided with a configuration assuming an application of being installed on a ship 20 and used for photographing work in calibration. Instead, for example, the calibration device 10 may have a configuration that is assumed to be installed in a fish cage where fish are cultivated and used for imaging work in calibration. For example, the installation members 19 and 27 of the photographing device fixing member 12 and the support member 14 are displaced to the circular cage frame 40 as shown in FIG. 7A or the square cage frame 40 as shown in FIG. 7B. It has a configuration that can be installed in a possible state. As an example of such a configuration, there is a configuration as shown in FIG. That is, the cage frame 40 may have a configuration in which a plurality of metal pipes (rod-shaped members) 41 as shown in FIG. 8 are arranged side by side. In this case, the installation members 19 and 27 include, for example, a grip portion 42 that grips the pipes 41 and a connecting portion (not shown) that connects the grip portion 42 to the support column members 18 and 26. When the grip portion 42 grips the pipe 41, the installation members 19 and 27 can attach the support member 18 of the photographing device fixing member 12 and the support member 26 of the support member 14 to the cage frame 40.

Further, in addition to the above-described configuration, the imaging device fixing member 12 and the support member 14 of the calibration device 10 may further have a configuration in which the water depth on which the imaging device 11 and the flat board 13 are installed can be adjusted. For example, the support columns 18 and 26 may have a structure that allows expansion and contraction in the extension direction S as shown in FIG.

Further, the photographing device fixing member 12 and the supporting member 14 of the calibration device 10 are oriented so that the photographing device 11 and the flat board 13 are oriented in a state where the installation members 19 and 27 are attached to the edge 20A of the ship 20 or the cage frame 40. It may have an adjustable configuration. For example, the support members 18 and 26 and the installation members 19 and 27 can rotate the photographing device 11 and the flat board 13 around the central axes of the support members 18 and 26 in the rotation direction K as shown in FIG. It may have a configuration which is connected by a connecting member having a function of performing.

By providing this configuration, the calibration device 10 can obtain the following effects. For example, it is assumed that the imaging device fixing member 12 and the supporting member 14 are attached to the circular cage frame 40 as shown in FIG. 7A, and the calibration imaging work is performed. In this case, when the mounting position of the support member 14 is shifted in the perspective direction with respect to the photographing device 11, if the curvature of the circular cage frame 40 is large, the photographing device 11 is shown in FIG. The inclination of the flat board 13 with respect to the above increases. As a result, the orientation of the flat board 13 with respect to the photographing device 11 may deviate from the state preferable for calibration. On the other hand, by making the photographing device 11 and the flat board 13 rotatable in the rotation direction K about the central axes of the support columns 18 and 26, the calibration device 10 determines the orientation of the flat board 13 with respect to the photographing device 11. Can have a function that is easy to adjust. Thereby, for example, even when the curvature of the cage frame 40 is large, the imaging work of the calibration can be satisfactorily executed.

Further, in the first embodiment, the photographing device 11 and the flat board 13 are arranged in water by installing the photographing device fixing member 12 and the supporting member 14 on the edge 20A of the ship 20 or the cage frame 40. Explaining. Instead, the photographing device fixing member 12 and the supporting member 14 may be arranged in the atmosphere.

<Second Embodiment>
The second embodiment according to the present invention will be described below.

FIG. 11 is a perspective view showing the configuration of the calibration device of the second embodiment in a simplified manner. The calibration device 50 of the second embodiment is a device for automating the underwater photographing work related to the calibration of the photographing apparatus by the plane method. The imaging device 60 that performs calibration using the calibration device 50 has the same configuration as the imaging device 11 described in the first embodiment.

The calibration device 50 in the second embodiment includes a flat board 51 which is a calibration member, a water storage device 52, a photographing device fixing member 53, a support member 54, a rotation mechanism (rotation device) 55, and a movement mechanism (movement). The device) 56 and the control device 57 are provided.

The flat board 51 has the same configuration as the flat board 13 described in the first embodiment. The flat board 51 has a size in consideration of the size of a space area (underwater area) required for calibration obtained by the area to be photographed by the photographing device 60 and the size of an object. Further, the amount of displacement of the flat board 51 during imaging of the flat board 51 for calibration is also set based on the size of the spatial region required for the calibration.

The water storage device 52 is a water tank having an open upper surface, and has a size capable of accommodating a flat board 51 in a state where it can be displaced by a predetermined displacement amount as described above. For example, when it is assumed that the photographing device 60 is used for observing fish cultivated in a cage, the width W inside the water storage device 52 (aquarium) in FIG. 11 is 1.5 meters. The depth H is designed to be 1.2 meters and the depth D is designed to be 3.8 meters. The inner wall surface of the water storage device 52 may be formed with a mark or the like that serves as a mark indicating the depth position or the distance from the photographing device 60.

The photographing device fixing member 53 is a member that functions as a device fixing portion for arranging the photographing device 60 inside the water storage device 52 by fixing the photographing device 60 to the wall portion of the water storage device 52. The configuration of the photographing device fixing member 53 is limited as long as the photographing device 60 can be arranged inside the water storage device 52 by fixing the photographing device 60 to the wall portion of the water storage device 52 in this way. This is not the case, and the description thereof will be omitted here. The photographing device fixing member 53 may have a configuration in which the height (depth) position in which the photographing device 60 is installed can be adjusted.

The support member 54 is a member that supports the flat board 51, and includes a beam portion 62 in the second embodiment. The beam portion 62 is arranged so as to hang between the wall portions of the water storage device 52 facing each other. The flat board 51 is connected to the beam portion 62 via a rotation shaft 63 and a rotation mechanism 55, which are attachment portions. The rotating shaft 63 is connected to the rotating mechanism 55 in a direction in which the central axis thereof is in a direction along the depth direction of the water storage device 52. The rotation mechanism 55 includes, for example, a stepping motor capable of controlling the rotation angle and a driving means for controlling energization of the motor, and the rotation shaft 63 can be rotated about the central axis thereof. The flat board 51 is fixed to the rotary shaft 63 so that the central axis of the rotary shaft 63 is along the plate surface of the flat board 51. As a result, the flat board 51 is attached to the beam portion 62 of the support member 54 so as to be rotatable in the rotational direction about the rotation shaft 63 by the rotational drive of the rotation mechanism 55. The rotating shaft 63 may be provided with a configuration in which the depth position of the flat board 51 can be adjusted. For example, the rotating shaft 63 may have a structure that can be expanded and contracted in a direction along the central axis.

The moving mechanism 56 has a configuration capable of moving the beam portion 62 of the support member 54 in the perspective direction toward or away from the photographing device 60. In the second embodiment, the moving mechanism 56 is provided at, for example, a motor (not shown), a driving means for controlling energization of the motor, and both ends of the beam portion 62 in order to control the moving amount. It is composed of a gear (not shown) that is rotated by a motor drive and a gear rail 65 that meshes with the gear. The gear rail 65 is arranged along the perspective direction with respect to the photographing device 60, and has a function of guiding (regulating) the moving direction of the beam portion 62.

The control device 57 includes, for example, a processor, and has a function of controlling the drive of the motor of the rotation mechanism 55 and the motor of the movement mechanism 56 by the processor. That is, the storage device included in the control device 57 is given a computer program representing a control procedure for controlling the motors of the rotation mechanism 55 and the movement mechanism 56. The processor controls the motors of the rotation mechanism 55 and the movement mechanism 56 by executing the computer program, and functions as a rotation operation unit for operating the rotation mechanism 55 and as a movement operation unit for operating the movement mechanism 56. Has a function.

Further, the storage device of the control device 57 is provided with a computer program representing a control procedure of the photographing work related to the calibration of the photographing device 60. The control device 57 controls the rotation mechanism 55 and the movement mechanism 56 by executing the computer program, thereby taking a picture of the flat board 51 while changing the position and inclination of the flat board 51 with respect to the picture device 60. Has a function to control.

Further, the control device 57 calculates a plurality of set parameters such as distortion correction parameters used in the distortion correction processing of the captured image by using the captured image of the photographing device 60 that has captured the flat board 51. A computer program for parameter calculation is given. The control device 57 has a function of calculating parameters such as distortion correction parameters by the captured image acquired from the photographing device 60 and a computer program for calculating the parameters thereof. Furthermore, the control device 57 is provided with a matrix calculation computer program that calculates a conversion matrix of 2D coordinates and 3D coordinates using the calculated parameters. The control device 57 has a function of calculating a conversion matrix of 2D coordinates and 3D coordinates by the calculated parameters and a computer program for matrix calculation.

The following method can be considered as a method for the control device 57 to acquire a photographed image from the photographing device 60. For example, a captured image captured by the photographing device 60 is stored in a portable storage medium (for example, a memory card) by the photographing device 60, and the control device 57 uses the portable storage medium to store the captured image of the photographing device 60. get. Alternatively, when the photographing device 60 and the control device 57 can be communicated and connected by wire or wirelessly, the control device 57 may acquire a photographed image from the photographing device 60 by communication.

In this way, when the control device 57 can acquire a captured image by communication, the control device 57 uses the captured image acquired every moment to obtain distortion correction parameters and 2D coordinates and 3D coordinates. The conversion matrix may be calculated by real-time processing. Further, when performing such a real-time calculation process, the control device 57 may further have the following functions. For example, the calculated parameters such as the distortion correction parameters and the conversion matrix of the 2D coordinate and the 3D coordinate are satisfactory because the number of data of the detection target points that can be used for calculating the distortion correction parameters is insufficient. It may not be the result. Assuming such a case, the control device 57 may further include a function of redoing the calculation process. For example, in the storage device of the control device 57, a plane board 51 for acquiring data of detection target points necessary for recalculating parameters such as distortion correction parameters and a matrix for converting 2D coordinates and 3D coordinates. A computer program is given to calculate the shooting position of. By executing the computer program, the control device 57 calculates the shooting position, rotation angle, and the like of the flat board 51 that acquires the data necessary for recalculating the distortion correction parameters and the like. Then, the control device 57 controls the operation of the rotation mechanism 55 and the moving mechanism 56 to shoot the flat board 51 in order to shoot the flat board 51 at the calculated shooting position. By providing such a function, the calibration device 50 can shorten the time required to redo the calculation process of the distortion correction parameter and the like.

The calibration device 50 of the second embodiment is configured as described above. The calibration device 50 executes the imaging work related to the calibration of the imaging device 60 as follows. For example, the operator installs the photographing device 60 and the flat board 51 so that the photographing device 60 and the flat board 51 face each other in the water of the water storage device 52. After that, during the imaging of the imaging device 60, the control device 57 controls the rotation mechanism 55 and the moving mechanism 56 according to a computer program, and separates the flat board 51 from the imaging device 60, for example, as shown in FIG. Rotate while moving in the direction. For example, the flat board 51 is moved within a range of a distance from the photographing device 60 from a position of 0.5 meters to 3 meters. Further, the rotation of the flat board 51 is performed in an angle range of 45 degrees to −45 degrees when the state of facing the photographing device 60 is set as a reference state (rotation angle of 0 degrees).

After the flat board 51 is photographed by the photographing device 60 in this way, as described above, the control device 57 uses the photographed image of the flat board 51 to perform parameters such as distortion correction parameters and 2D coordinates and 3D coordinates. Calculate the conversion matrix of.

Since the calibration device 50 of the second embodiment includes the photographing device 60 and the water storage device 52 accommodating the flat board 51, the work of photographing the flat board 51 in water related to the calibration of the photographing device 60 can be performed on the sea or in the sea. It is possible to do it without going to a lake, etc., and it is possible to improve convenience.

Further, the calibration device 50 has a configuration in which the movement and rotation of the flat board 51 can be controlled by the control device 57. Therefore, since it is not necessary for the operator to move and rotate the flat board 51, the calibration device 50 can reduce the burden of the imaging work related to the calibration. In addition, the calibration device 50 can shorten the time required for the photographing work related to the calibration.

In the second embodiment, an example of performing calibration by the plane method is shown, but the calibration device 50 of the second embodiment has a configuration capable of performing calibration by the DLT (Direct Linear Transformation) method. You may have it. For example, the rotating shaft 63 is also provided with a configuration in which a rectangular parallelepiped frame structure 70, which is a calibration member used in the DLT method as shown in FIG. 13, can be detachably connected. Further, the storage device of the control device 57 is provided with a computer program that calculates distortion correction parameters using the DLT method.

Then, when performing calibration using the DLT method, for example, an operator connects the frame structure 70 to the rotation shaft 63 of the support member 54. Further, the frame structure 70 is arranged manually by the operator or the control device 57 controls the moving mechanism 56 so that the distance from the photographing device 60 becomes a predetermined distance. The photographing device 60 photographs the frame structure 70 arranged in this way, and the control device 57 determines a predetermined detection target point (such as the apex of the frame structure 70) from the photographed image of the frame structure 70 by the photographing device 60. Detect. After that, the control device 57 calculates parameters such as distortion correction parameters using the data of the detected detection target points, and further calculates a conversion matrix of 2D coordinates and 3D coordinates.

When photographing the frame structure 70, the depth position may be adjusted by adjusting the orientation of the frame structure 70 by the rotation mechanism 55 or adjusting the expansion and contraction of the rotation shaft 63.

Further, even when the calibration is performed by using the DLT method, the control device 57 may be provided with a configuration capable of redoing the same calculation process.

Further, the calibration device 50 of the second embodiment may have a configuration in which the calibration device 50 of the second embodiment is calibrated by the DLT method using the flat board 51 without using the frame structure 70. For example, when performing calibration using the DLT method, the flat board 51 is not rotated by the rotating mechanism 55, and the control device 57 is flat in the perspective direction approaching or moving away from the photographing device 60 by the moving mechanism 56. Move the board 51. The control device 57 utilizes the detection target points on the plane board 51 taken at a plurality of preset moving positions different from each other, and uses the DLT method to perform parameters such as distortion correction parameters and a matrix for converting 2D coordinates and 3D coordinates. Is calculated.

<Other Embodiments>
The present invention is not limited to the first and second embodiments, and various embodiments can be adopted. For example, in the calibration device 50 of the second embodiment, the flat board 51 is supported by the wall portion of the water storage device 52 in a double-sided beam shape, but the flat board 51 is cantilevered while considering the mechanical strength. It may be supported by the water storage device 52 in a beam-like manner.

Further, in the first and second embodiments, the planar method or the DLT method is adopted as the calibration method, but a calibration method other than the planar method or the DLT method may be adopted, and the adopted method may be used. Accordingly, the movements of the flat boards 13 and 51 are controlled by the operator and the control device 57.

FIG. 14 is a block diagram showing a simplified configuration of a calibration device according to another embodiment of the present invention. The calibration device 80 includes a support member 81 and a calibration member 82. The calibration member 82 is a member having a detection target point used for calibrating the photographing apparatus. The support member 81 includes a configuration that supports the calibration member 82 in a displaceable state in a perspective direction in which the calibration member 82 approaches or moves away from the photographing device for photographing the calibration member 82.

Since the calibration device 80 can support the calibration member 82 in a displaceable state by the support member 81, for example, while the calibration member 82 is being photographed for calibration, the operator can support the calibration member 82. You can eliminate the burden of keeping the. When the area to be calibrated of the photographing device is large, it is assumed that the calibration member 82 becomes large and the amount of movement of the calibration member 82 increases, which may increase the burden on the operator. I am concerned. The calibrator 80 is particularly effective when there is concern that the burden on such an operator will increase.

The present invention has been described above using the above-described embodiment as a model example. However, the present invention is not limited to the above-described embodiments. That is, the present invention can apply various aspects that can be understood by those skilled in the art within the scope of the present invention.

This application claims priority on the basis of Japanese application Japanese Patent Application No. 2018-090501 filed on May 9, 2018, the entire disclosure of which is incorporated herein by reference.

10,50 Calibration device 11,60 Imaging device 13,51 Flat board 12,53 Imaging device fixing member 14,54 Support member

Claims (8)

A calibration member with a detection target point used for calibration of the imaging device,
A calibration device including a support member that supports the calibration member in a displaceable state in a perspective direction that approaches or moves away from the image pickup device that photographs the calibration member. The support member includes a mounting portion for attaching the calibration member in a rotatable state, an operation portion for operating the rotation of the calibration member, and further, with respect to the imaging device for photographing the calibration member. A claim including a hooking portion that locks on a locking receiving portion that extends in the perspective direction that approaches or moves away, or a grip portion that grips a rod-shaped member that extends in the perspective direction that approaches or moves away from the imaging device that photographs the calibration member. Item 1. The calibration device according to item 1. The support member has a beam portion that supports the calibration member so as to be displaceable in a perspective direction that approaches or moves away from the imaging device that photographs the calibration member, and a rotation axis that extends in a direction that intersects the beam portion. A mounting portion for attaching the calibration member to the beam portion in a rotatable state is provided at the center.
A rotating device that rotationally drives the calibration member,
The calibration device according to claim 1, further comprising a rotation operation unit for operating the rotation device. A moving device that moves the beam portion in a perspective direction that approaches or moves away from the photographing device that photographs the calibration member, and a moving device that moves the beam portion.
The calibration device according to claim 3, further comprising a moving operation unit for operating the moving device. The central axis of rotation of the calibration member is a direction orthogonal to the side-by-side direction of a plurality of imaging units constituting the imaging device and the perspective direction of approaching or moving away from the imaging device for imaging the calibration member. The calibrator according to any one of claims 2 to 4. The calibration device according to any one of claims 1 to 5, further comprising a water storage device capable of storing the calibration member in a displaceable state. The calibration device according to any one of claims 1 to 6, further comprising a device fixing portion for fixing the imaging device for photographing the calibration member. A calibration member having a detection target point used for calibrating the imaging device is supported by the support member in a state of being displaceable in the perspective direction toward or away from the imaging device.
The calibration member is photographed by the imaging device while the calibration member is displaced.
A calibration method in which a detection target point is detected from an image captured by the calibration member by the imaging device, and the imaging device is calibrated using the detected detection target point.

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