WO2019216297A1 - Calibration device and calibration method - Google Patents

Abstract

In order to provide a technology for reducing the burden of calibration-related operations, a calibration device 80 is provided with a support member 81 and a calibration member 82. The calibration member 82 has a point to be detected which is used in the calibration of an imaging device. The support member 81 is configured to support the calibration member 82 in a state in which the calibration member 82 can be displaced in a far/close direction in which the calibration member 82 moves closer to or farther from the imaging device which images the calibration member 82.

Description

Calibration apparatus and calibration method

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

Photographer apparatuses include what are called stereo cameras and 3D (Dimensions) cameras. Such an imaging apparatus has a configuration capable of generating binocular parallax by having a plurality of imaging units and simultaneously imaging an object from a plurality of different directions, thereby generating a stereoscopic photograph. The imaging apparatus 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, in a photographed image by the photographing apparatus, a distortion caused by a focal length, a center position shift, lens distortion, and the like, which is different for each lens occurs. The image distortion correction function provided in the imaging apparatus or the information processing apparatus is a function for correcting such distortion of the captured image. For example, the distortion correction parameters used in the processing by the 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 captures a two-dimensional pattern drawn on a plane board while changing the inclination, position, etc. of the plane board using a calibration target imaging apparatus. Then, for example, a distortion correction parameter is calculated by the information processing apparatus using the photographed 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 a region to be monitored or an object to be observed is observed (monitored) using an image captured by the photographing device. In such a case, when acquiring information such as the size of an object shown in the captured image from the captured image, in order to increase the reliability of the acquired information, the area of the monitoring target or the observation target It is preferable to calibrate the photographing apparatus for a spatial region having a size corresponding to the size of the object.

However, there is a problem that the burden on the operator who performs 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 employed, there is an operation of moving a flat board used for calibration. When the plane board becomes larger in accordance with the size of the space area to be calibrated, the burden of work for changing the inclination and position of the plane board due to the size and weight of the plane board increases. In particular, when the region to be calibrated is underwater because the object to be observed exists in water, the burden on the operator increases. For example, when the calibration target region is underwater, it is conceivable that the operator manipulates the underwater flat board from the ship. In this case, the worker's scaffolding is poor and the posture of the worker is likely to be unstable. In addition, when the flat board becomes large, the water pressure received by the flat board increases, and the work load for 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 calibration device of the present invention comprises:
A calibration member having a detection target point to be used in calibration of the imaging device;
A support member that supports the calibration member in a displaceable state in a perspective direction approaching or moving away from the imaging device that captures the calibration member.

Moreover, the calibration method of the present invention includes:
A calibration member having a detection target point to be used for calibration of the imaging device is supported by a support member in a displaceable direction toward or away from the imaging device.
Photographing the calibration member by the photographing device while displacing the calibration member,
The detection target point is detected from a 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 composition of the calibration device of a 1st embodiment concerning the present 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 comprises the calibration apparatus of 1st Embodiment. It is a figure explaining the rotation displacement of the plane board which is a member for calibration in a 1st embodiment. It is a figure explaining the plane method which is one of the calibration methods. It is a figure explaining the operation | work which image | photographs a plane board in the calibration using the calibration apparatus of 1st Embodiment. It is a figure explaining the example of 1 aspect of a sacrifice frame. It is a figure explaining another example of a sacrifice frame. It is a figure explaining the structural example which attaches the installation member which comprises the calibration apparatus of 1st Embodiment to a sacrifice frame. It is a figure explaining the modification of the calibration apparatus represented by FIG. It is a figure explaining the effect in case a calibration apparatus has the structure which the support | pillar member which supports a plane board can rotate 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 operation | work which image | photographs a plane board in the calibration using the calibration apparatus of 2nd Embodiment. It is a figure explaining one example of a case where the calibration device of a 2nd embodiment is used for calibration by DLT (Direct Linear Linear Transformation) method. It is a figure explaining the structure of the calibration apparatus of other embodiment which concerns on this invention.

Embodiments according to the present invention will be described below with reference to the drawings.

<First Embodiment>
FIG. 1 shows an example of a calibration apparatus according to a first embodiment of the present invention together with an imaging apparatus. The calibration device 10 according to the first embodiment is a device used for photographing the calibration member (planar board 13) in water during calibration of the photographing device 11. Further, in the example of FIG. 1, the photographing apparatus 11 has a frame in a state in which two cameras (photographing units) 15 and 16 are arranged in parallel with an interval (for example, a base line length is 0.3 to 0.9 meter). The structure fixed to the member etc. is provided. With such a configuration, the photographing apparatus 11 has a function capable of photographing a target object from a plurality of different directions at the same time and thereby generating binocular parallax to generate a stereoscopic photograph. In addition, the cameras 15 and 16 which comprise the imaging device 11 are provided with the function which image | photographs a moving image or a still image, and the lens provided in the said cameras 15 and 16 has faced the same direction.

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

The flat board 13 is a calibration member photographed by the photographing apparatus 11 for calibration of the photographing apparatus 11, and a pattern (two-dimensional pattern) including detection target points used for calibration is formed on the surface thereof. Yes. A pattern (hereinafter also referred to as a calibration pattern) formed on the flat board 13 is a pattern in which a predetermined detection target point can be easily recognized from a captured image. For example, the calibration pattern includes a checker (checkered) pattern and a pattern in which circles and square dots are arranged at intervals.

The plane board 13 has a size that takes into account the size of the area to be calibrated. For example, when the size of the area to be calibrated is about 1 meter long, 1 meter wide, and 3 meters deep, the plane board 13 is 1 meter long and 0.7 meters wide. Have Further, the plane board 13 is set in thickness (for example, about 1 millimeter) and material (for example, metal such as aluminum or resin material) in consideration of weight reduction and mechanical strength.

In addition, it may replace with the plane board 13 of the said structure, and may employ | adopt the thing of the following structures as the plane board 13. FIG. For example, a sheet having a configuration in which a sheet (a cloth sheet, a resin sheet, a metal sheet, or the like) on which a calibration pattern is formed is stretched inside the frame may be employed as the flat board 13. 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). If there is such a concern, for example, the braces inside the frame Such a reinforcing material may be formed. Furthermore, instead of the configuration in which the sheet is stretched inside the frame, a configuration in which rod members are arranged in a lattice shape inside the frame may be employed as the flat board 13. In this case, for example, bars arranged in a grid form a calibration pattern, and an intersection of the grid bars is set as a detection target point used for calibration.

In the plane method using the plane board 13 as described above, as shown in the image diagram of FIG. 5, while the inclination and position of the plane board 13 with respect to the imaging apparatus 11 are changed, the imaging board 11 uses the plane board 13. A calibration pattern is photographed. And the predetermined detection target point in the some picked-up image image | photographed in this way is detected (extracted) by a computer (information processing apparatus), for example. Furthermore, using the position of the detection target point in the captured image, a plurality of set parameters such as distortion correction parameters used in the distortion correction processing of the captured image are calculated by the computer. Furthermore, 2D coordinates for converting 2D (Dimensions) coordinates in the captured image into 3D (Dimensions) coordinates and a matrix for conversion of 3D coordinates are calculated by the computer using these parameters. Here, the distortion correction parameter and the method for calculating the matrix for conversion between 2D coordinates and 3D coordinates are not particularly limited, and description thereof is omitted.

The imaging device fixing member 12 has a support member 18 as shown in FIG. The photographing device 11 is fixed to the support member 18 by, for example, spiral fastening. An installation member 19 is provided on one end side of the support member 18. As shown in FIG. 2, the installation member 19 includes a configuration that allows the support member 18 to be attached to the edge 20 </ b> A of the ship 20. The installation member 19 is a member that allows the photographing device 11 to be suspended outside the ship by the support member 18 and placed in water by attaching the support member 18 to the edge 20 </ b> A of the ship 20. The configuration of the installation member 19 is not particularly limited as long as the 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 where the installation member 19 is 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 part 22 has a mode of fitting with the edge 20 </ b> A of the ship 20. The claw portion 23 is a portion that functions as a hook portion that is engaged with a rod-shaped member (for example, a rod made of stainless steel) 21 that extends along the edge 20 </ b> A of the boat 20 inside the boat 20. That is, the installation member 19 shown in FIG. 3 is a member that hooks the photographing apparatus 11 on the edge 20 </ b> A of the ship 20 via the support member 18. Further, when the installation member 19 has a configuration as shown in FIG. 3, the rod-like member 21 functions as a latch receiving portion that latches the claw portion (hook 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 20 </ b> A of the ship 20, the installation member 19 includes a pedestal (weight) installed on the deck of the ship 20, the pedestal and the column. The structure which has the connection member which connects the member 18 may be sufficient.

The support member 14 is a support member that supports the flat board 13, which is a calibration member used for calibration of the photographing apparatus 11, on the edge 20 </ b> A of the ship 20. As shown in FIG. 1, the support member 14 includes a support member 26. The support member 26 is provided with an installation member 27 on one end side thereof, and an attachment portion 28 is provided.

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

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

As shown in FIG. 4, the attachment portion 28 having the above-described configuration can attach the flat board 13 to the column member 26 in a state in which it can be rotationally displaced about the central axis of the rotary shaft 30. .

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

The support member 14 is configured as described above. When the installation member 27 of the support member 14 is attached to the edge 20A of the ship 20 and the support member 26 is suspended from the outside of the ship, the flat board 13 can be placed in water.

In 1st Embodiment, when the imaging device 11 and the plane board 13 are each installed in the ship 20 by the imaging device fixing member 12 and the support member 14, so that it may become a positional relationship as represented in FIG. 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, and the parallel direction of the cameras 15 and 16 of the photographing apparatus 11 is the X direction, and the flat board 13 approaches the photographing apparatus 11. Alternatively, the perspective direction that moves away is taken as the Z direction. The juxtaposed direction of the cameras 15 and 16 of the imaging device 11 fixed to the imaging 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 attachment angle between the support member 26 and the rotary shaft 30 in the support member 14 and the height (hanging) position of the imaging device 11 and the flat board 13 are appropriately designed.

The calibration device 10 of the first embodiment is configured as described above. The photographing operation of the flat board 13 related to the calibration of the photographing device 11 using the calibration device 10 is performed as follows. For example, when the operator hooks and installs the photographing device fixing member 12 to which the photographing device 11 is fixed on the edge 20 </ b> A of the ship 20, the photographing device 11 is placed in the water outside the ship. Further, the operator places the support member 14 to which the flat board 13 is attached on the edge 20 </ b> A of the ship 20 to place 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 plane board 13 is located at the P1 position (for example, the distance between the imaging device 11 and the plane board 13 is about 1 meter) which is a predetermined imaging position shown in FIG. In a state where shooting or continuous shooting of still images is being performed, the operator uses the operation unit 32 to rotate and displace the flat board 13. Thereafter, the operator changes the hooking position of the support member 14 on the edge 20A of the ship 20, and moves the plane board 13 to the P2 position (for example, the interval between the imaging device 11 and the plane board 13 is a predetermined next shooting position). Move to about 2 meters). In the same manner as described above, the operator rotates and displaces the flat board 13 using the operation unit 32 while the photographing apparatus 11 is operating.

As described above, the operator causes the photographing device 11 to photograph the calibration pattern of the flat board 13 while changing the position of the flat board 13 and rotating the flat board 13.

After such a photographing operation, a predetermined detection target point is extracted from the calibration pattern in the photographed image, for example, by a computer (information processing apparatus). Then, parameters such as distortion correction parameters are calculated by, for example, a computer using the extracted detection target points. Further, a conversion matrix between 2D coordinates and 3D coordinates is calculated by, for example, a computer using the calculated parameters. Note that, here, there is no limitation on the method of extracting the detection target point, the method of calculating the distortion correction parameter, and the conversion matrix of 2D coordinates and 3D coordinates, and the description thereof is omitted.

The calibration apparatus 10 according to the first embodiment can reduce the burden on the operator of the shooting work related to calibration by having the above-described configuration. In other words, the calibration device 10 can be installed by hooking the photographing device 11 and the flat board 13 on the edge 20 </ b> A of the ship 20. For this reason, the use of the calibration device 10 eliminates the need for the operator to continue to hold the photographing device 11 and the flat board 13 on a ship with a poor foothold during calibration photographing. Thereby, the calibration apparatus 10 can reduce an operator's burden. In addition, the calibration device 10 can improve the workability because the plane board 13 can be easily moved by only one work vehicle.

Furthermore, since the calibration device 10 can support the plane board 13 on the edge 20A of the ship 20 during photographing for calibration, the size of the plane board 13 can be increased while suppressing an increase in the burden on the operator. It becomes easy. Thereby, the calibration apparatus 10 can easily realize calibration corresponding to the enlargement of the area to be calibrated.

Furthermore, since the calibration device 10 has a simple configuration, it is easy to carry.

By the way, in 1st Embodiment, the calibration apparatus 10 is equipped with the structure supposing the use which is installed in the ship 20 and used for the imaging | photography operation | work in a calibration. Instead of this, for example, the calibration device 10 may have a configuration that is assumed to be installed in a fish cage that is cultivating fish and used for photographing work in calibration. For example, the photographing device fixing member 12 and the installation members 19 and 27 of the support member 14 are displaced into a circular sacrifice frame 40 as shown in FIG. 7A or a rectangular sacrifice frame 40 as shown in FIG. 7B. It has a configuration that can be mounted in a possible state. As an example of such a configuration, there is a configuration as shown in FIG. That is, the sacrifice frame 40 may have a configuration in which a plurality of metal pipes (rod-like members) 41 as shown in FIG. In this case, the installation members 19 and 27 include, for example, a grip portion 42 that grips the pipes 41 and a connection portion (not shown) that connects the grip portion 42 to the support members 18 and 26. When the grip portion 42 grips the pipe 41, the installation members 19 and 27 can attach the column member 18 of the imaging device fixing member 12 and the column member 26 of the support member 14 to the sacrifice frame 40.

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 include a configuration capable of adjusting the water depth at which the imaging device 11 and the flat board 13 are installed. For example, the support members 18 and 26 may have a configuration that can be expanded and contracted in the extending direction S as shown in FIG.

Further, the photographing device fixing member 12 and the support member 14 of the calibration device 10 are arranged so that the photographing device 11 and the plane board 13 are oriented in the state where the installation members 19 and 27 are attached to the edge 20A of the ship 20 or the sacrifice frame 40. An adjustable configuration may be provided. For example, the support members 18 and 26 and the installation members 19 and 27 can rotate the photographing apparatus 11 and the flat board 13 in the rotation direction K as shown in FIG. 9 about the central axis of the support members 18 and 26. You may provide the structure connected by the connection member with the function to do.

By providing this configuration, the calibration device 10 can obtain the following effects. For example, assume that the photographing device fixing member 12 and the support member 14 are attached to a circular sacrifice frame 40 as shown in FIG. In this case, if the curvature of the circular sacrifice frame 40 is large when the mounting position of the support member 14 is shifted in the perspective direction with respect to the photographing apparatus 11, as shown in FIG. The inclination of the flat board 13 with respect to is increased. As a result, the orientation of the flat board 13 with respect to the photographing apparatus 11 may deviate from a preferable state for calibration. On the other hand, the calibration device 10 is configured so that the orientation of the planar board 13 with respect to the imaging device 11 by allowing the imaging device 11 and the planar board 13 to rotate in the rotation direction K around the central axis of the support members 18 and 26. Can be easily adjusted. Thereby, for example, even when the curvature of the sacrifice frame 40 is large, the photographing operation for calibration can be performed satisfactorily.

Moreover, in 1st Embodiment, the imaging device 11 and the plane board 13 are arrange | positioned in water by installing the imaging device fixing member 12 and the supporting member 14 in the edge 20A of the ship 20 or the sacrifice frame 40. Explains. Instead of this, the imaging device fixing member 12 and the support 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 simplified perspective view showing the configuration of the calibration apparatus according to the second embodiment. The calibration device 50 according to the second embodiment is a device that automates a photographing operation in water according to the calibration of the photographing device by the plane method. An 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 according to the second embodiment includes a flat board 51 as 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). Device) 56 and a control device 57.

The planar board 51 has the same configuration as the planar board 13 described in the first embodiment. The plane board 51 has a size that takes into account the size of the space area (underwater area) necessary for calibration determined by the area to be imaged by the imaging apparatus 60 and the size of the object. Further, based on the size of the space area necessary for the calibration, the amount of displacement of the flat board 51 during photographing of the flat board 51 for calibration is also set.

The water storage device 52 is a water tank whose upper surface is open, and has a size that allows the flat board 51 to be accommodated in a state where the predetermined amount of displacement is possible. For example, when it is assumed that the photographing device 60 is used for observing fish that are cultivated in a cage, the width W inside the water storage device 52 (water tank) 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. It should be noted that a mark or the like representing a depth position or a distance from the imaging device 60 may be formed on the inner wall surface of the water storage device 52.

The photographing device fixing member 53 is a member that functions as a device fixing portion that places 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 imaging device fixing member 53 is limited as long as the imaging device 60 can be disposed inside the water storage device 52 by fixing the imaging device 60 to the wall portion of the water storage device 52 as described above. The description thereof is omitted here. In addition, the imaging device fixing member 53 may include a configuration capable of adjusting a height (depth) position where the imaging device 60 is installed.

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 part 62 is arrange | positioned so that between the wall parts which the water storage apparatus 52 mutually faces may be spanned. 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 rotation shaft 63 is connected to the rotation mechanism 55 in such a direction that the center axis thereof is a direction along the depth direction of the water storage device 52. The rotation mechanism 55 includes, for example, a stepping motor that can control the rotation angle and a drive unit that controls energization of the motor, and can rotate the rotation shaft 63 around the central axis. 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. Accordingly, the flat board 51 is attached to the beam portion 62 of the support member 54 so as to be rotatable in the rotation direction around the rotation shaft 63 by the rotation drive of the rotation mechanism 55. The rotation shaft 63 may be provided with a configuration that can adjust the depth position of the flat board 51. For example, the rotating shaft 63 may have a configuration that can expand and contract 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 a perspective direction approaching or moving away from the imaging device 60. In the second embodiment, the moving mechanism 56 is provided at both ends of the beam unit 62 and, for example, a motor (not shown), a driving unit that controls energization of the motor, and the beam unit 62 in order to control the amount of movement. A gear (not shown) that rotates by driving a motor and a gear rail 65 that meshes with the gear are configured. The gear rail 65 is disposed along the perspective direction with respect to the imaging 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 driving of the motor of the rotation mechanism 55 and the motor of the moving mechanism 56 by the processor. That is, a computer program representing a control procedure for controlling the motors of the rotation mechanism 55 and the movement mechanism 56 is given to the storage device included in the control device 57. 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 that operates the rotation mechanism 55 and a movement operation unit that operates the movement mechanism 56. Has function.

In addition, the storage device of the control device 57 is provided with a computer program representing the control procedure of the photographing work related to the calibration of the photographing device 60. The control device 57 executes the computer program to control the rotating mechanism 55 and the moving mechanism 56, thereby photographing the flat board 51 while changing the position and inclination of the flat board 51 with respect to the photographing device 60. Has a function to control.

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

Note that the following method can be considered as a method for the control device 57 to acquire a captured image from the image capturing device 60. For example, a photographed image photographed 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 display a photographed image of the photographing device 60. get. Alternatively, in a case where the imaging device 60 and the control device 57 can be connected by wire or wirelessly, the control device 57 may acquire a captured image from the imaging device 60 through communication.

In this way, when the control device 57 can acquire a captured image through communication, the control device 57 uses the captured image acquired every moment to allow the control device 57 to calculate distortion correction parameters, 2D coordinates, and 3D coordinates. The conversion matrix may be calculated by real-time processing. Furthermore, when performing such real-time calculation processing, the control device 57 may further include the following functions. For example, the calculated parameters for distortion correction and the conversion matrix for 2D coordinates and 3D coordinates are satisfactory because the number of data of detection target points available for calculation of distortion correction parameters is insufficient. It may not be a result. Assuming such a case, the control device 57 may further include a function of performing the calculation process again. For example, in the storage device of the control device 57, the plane board 51 for acquiring the data of the detection target points necessary for redoing the calculation processing of the parameters such as the distortion correction parameters and the conversion matrix of 2D coordinates and 3D coordinates. A computer program for calculating the shooting position is provided. The control device 57 executes the computer program to calculate the shooting position, rotation angle, and the like of the flat board 51 that acquires data necessary for redoing the calculation processing of the distortion correction parameters and the like. Then, the control device 57 controls the operation of the rotation mechanism 55 and the movement mechanism 56 to capture the plane board 51 so as to capture the plane board 51 at the calculated imaging position. By providing such a function, the calibration device 50 can shorten the time required for re-execution of the calculation process of the distortion correction parameters and the like.

The calibration device 50 of the second embodiment is configured as described above. The calibration device 50 performs a photographing operation related to calibration of the photographing 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. Thereafter, during the photographing of the photographing device 60, the control device 57 controls the rotating mechanism 55 and the moving mechanism 56 according to the computer program, and the plane board 51 is moved away from the photographing device 60, for example, as shown in FIG. Rotate while moving in the direction. For example, the movement of the flat board 51 is performed in a range from a position of 0.5 meters to 3 meters from the photographing device 60. Further, the rotation of the flat board 51 is performed in an angle range from 45 degrees to −45 degrees when the state facing the imaging device 60 is a reference state (rotation angle 0 degree).

After the plane board 51 is imaged by the imaging device 60 in this way, the control device 57 uses the captured image of the plane board 51 to set parameters such as distortion correction parameters, 2D coordinates and 3D coordinates as described above. The matrix for conversion is calculated.

Since the calibration device 50 according to the second embodiment includes the water storage device 52 that accommodates the imaging device 60 and the flat board 51, the imaging work of the flat board 51 in water according to the calibration of the imaging device 60 This makes it possible to do this without going to the lake, and can 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. For this reason, it is not necessary to perform the work of moving and rotating the flat board 51 by the operator, and therefore the calibration device 50 can reduce the burden of the photographing work related to the calibration. In addition, the calibration device 50 can shorten the time for the photographing work related to calibration.

In the second embodiment, the example of performing calibration by the plane method has been described. However, the calibration apparatus 50 of the second embodiment has a configuration that can also perform calibration by the DLT (Direct Linear Transformation) method. You may have. For example, it is assumed that the rotating shaft 63 also has 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 given a computer program for calculating distortion correction parameters using the DLT method.

And when calibrating using the DLT method, for example, the operator connects the frame structure 70 to the rotating shaft 63 of the support member 54. Further, the frame structure 70 is arranged manually by an 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 imaging device 60 captures the frame structure 70 arranged in this way, and the control device 57 selects a predetermined detection target point (such as the vertex of the frame structure 70) from the captured image of the frame structure 70 by the imaging device 60. Detect. Thereafter, the control device 57 calculates parameters such as distortion correction parameters using the detected detection target data, 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 by adjusting the expansion and contraction of the rotation shaft 63.

Further, even when calibration is performed using the DLT method, the control device 57 may include a configuration capable of performing the same calculation process again.

Furthermore, the calibration device 50 according to the second embodiment may have a configuration in which calibration by the DLT method is performed using the flat board 51 without using the frame structure 70. For example, when calibration using the DLT method is performed, the rotating board 55 is not rotated by the rotating mechanism 55, and the control device 57 is flattened in the perspective direction approaching or moving away from the imaging device 60 by the moving mechanism 56. The board 51 is moved. The control device 57 uses detection target points on the flat board 51 photographed at a plurality of different movement positions set in advance, and uses parameters such as distortion correction parameters and a matrix for converting 2D coordinates and 3D coordinates by the DLT method. Is calculated.

<Other embodiments>
In addition, this invention is not limited to 1st and 2nd embodiment, Various aspects can be taken. For example, in the calibration device 50 of the second embodiment, the flat board 51 is supported on the wall of the water storage device 52 in a doubly supported beam shape, but the flat board 51 is cantilevered in consideration of mechanical strength. It may be supported by the water storage device 52 in a beam-like manner.

In the first and second embodiments, the planar method or the DLT method is adopted as the calibration method. However, a calibration method other than the planar method or the DLT method may be adopted. Accordingly, the movement of the flat boards 13 and 51 is controlled by the operator and the control device 57.

FIG. 14 is a block diagram showing a simplified configuration of a calibration apparatus 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 calibration of the imaging apparatus. The support member 81 includes a configuration that supports the calibration member 82 in a displaceable state in a near-to-far direction approaching or moving away from the imaging device that photographs the calibration member 82.

Since the calibration device 80 can support the calibration member 82 by the support member 81 in a displaceable state, for example, the operator can calibrate the calibration member 82 while photographing the calibration member 82 for calibration. You can eliminate the burden of continuing to hold. When the area to be calibrated by the photographing apparatus is large, it is assumed that the calibration member 82 is increased and the amount of movement of the calibration member 82 is increased, which increases the burden on the operator. Concerned. The calibration device 80 is particularly effective when there is a concern that the burden on such an operator increases.

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

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

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 having a detection target point to be used in calibration of the imaging device;
A calibration apparatus comprising: a support member that supports the calibration member in a displaceable state toward and away from the imaging apparatus that images the calibration member. The support member includes an attachment unit for attaching the calibration member in a rotatable state, and an operation unit for operating the rotation of the calibration member, and further, with respect to the imaging apparatus for imaging the calibration member A hooking portion that locks on a locking receiving portion that extends in a near or near direction that approaches or moves away, or a gripping portion that grips a rod-shaped member that extends in a near or far direction toward or away from the imaging device that photographs the calibration member. Item 2. The calibration device according to Item 1. The support member includes 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 images the calibration member, and a rotation axis that extends in a direction intersecting the beam portion. An attachment portion for attaching the calibration member to the beam portion in a rotatable state around the center;
A rotating device that rotationally drives the calibration member;
The calibration device according to claim 1, further comprising a rotation operation unit that operates the rotation device. A moving device that moves the beam portion in a perspective direction that approaches or moves away from the imaging device that images the calibration member;
The calibration apparatus according to claim 3, further comprising a movement operation unit that operates the movement apparatus. A central axis of rotation of the calibration member is a direction orthogonal to a parallel arrangement direction of a plurality of imaging units constituting the imaging device and a perspective direction approaching or moving away from the imaging device imaging the calibration member. The calibration device according to any one of claims 2 to 4, wherein The calibration device according to any one of claims 1 to 5, further comprising a water storage device that houses the calibration member in a displaceable state and can store water. The calibration device according to any one of claims 1 to 6, further comprising a device fixing unit that fixes the imaging device that images the calibration member. A calibration member having a detection target point to be used for calibration of the imaging device is supported by a support member in a displaceable direction toward or away from the imaging device.
Photographing the calibration member by the photographing device while displacing the calibration member,
A calibration method for detecting the detection target point from a captured image of the calibration member by the imaging apparatus and calibrating the imaging apparatus using the detected detection target point.

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