JP4816464B2 - Lens calibration method, lens calibration device, imaging device calibration method, and calibration device - Google Patents

Description

  The present invention relates to a lens calibration method using a calibration pattern, a lens calibration device, an imaging device calibration method, and a calibration device.

In the image processing technology, it is the most basic matter to quantitatively grasp what kind of image is obtained through a lens. Therefore, a so-called calibration is performed in which an image is generated by capturing a predetermined pattern (calibration pattern) through a lens, and various conditions are set based on the image (for example, Patent Document 1). reference).
JP 2000-350239 A

However, in the calibration of a lens whose magnification near the optical axis is higher than the magnification around it, such as an equidistant projection optical system or a foveal optical system, or a calibration in a photographing apparatus equipped with such a lens, Because of the large viewing angle, calibration may be difficult.
In order to cover the entire field of view when calibrating a lens with a large viewing angle, the lens and the calibration pattern are made extremely close to each other, or a calibration pattern with a size that can cover the entire field of view is prepared. There is a need. When the lens and the calibration pattern are brought close to each other, problems such as accuracy, a problem that an image of the lens itself is reflected in the calibration pattern, and a problem that it is difficult to uniformly illuminate the calibration pattern occur. In addition, when preparing a calibration pattern having a size that can cover the entire field of view, there are problems such as a large installation location and distortion of the calibration pattern itself accompanying an increase in size.

Furthermore, in the calibration of a fisheye lens or the like having a very large viewing angle, the entire field of view cannot be covered with a flat calibration pattern. Therefore, it is conceivable to use a dome-shaped calibration pattern, but it is difficult to create and has a problem in accuracy.
Note that the above-described problems also occur in calibration in an imaging apparatus having a lens with a large viewing angle.

  An object of the present invention is to efficiently calibrate a lens having a large viewing angle, such as an equidistant projection optical system and a foveal optical system, or a photographing apparatus including such a lens.

The lens calibration method of the present invention is a lens calibration method using a calibration pattern, and the relative positional relationship between the lens and the calibration pattern according to the viewing angle of the lens. Information necessary for calibration of the lens based on the plurality of images, and an imaging step of capturing the projection image of the calibration pattern through the lens a plurality of times to generate a plurality of images Bei example and an acquisition step of acquiring, in the imaging step, the calibration pattern is arranged at a predetermined angle with respect to the optical axis and is perpendicular the plane of the lens.

Preferably, in the imaging step, the plurality of images may be generated while relatively rotating the lens and the calibration pattern with the optical axis of the lens as a rotation axis.
Preferably, in the imaging step, at least two images having line symmetry may be generated with a perpendicular perpendicular to the optical axis of the lens as an axis of symmetry.

Preferably, the plurality of images generated by the imaging step have an overlapping portion between adjacent images, and the plurality of images can cover the entire field of view of the lens. Good .

The lens calibration apparatus according to the present invention includes a changing unit that changes a relative positional relationship between the lens and the calibration pattern, and an image obtained by capturing a projection image of the calibration pattern via the lens. And the imaging unit that controls the imaging unit while changing the relative positional relationship between the lens and the calibration pattern according to the viewing angle of the lens. wherein the projection image of the calibration pattern is captured a plurality of times, e Bei a control unit for generating a plurality of images, and an acquisition unit for acquiring information necessary for the calibration of the lens based on the plurality of images, The calibration pattern is arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens .

Preferably, the changing unit may relatively rotate the lens and the calibration pattern with the optical axis of the lens as a rotation axis.
Preferably, the changing unit has a relative position between the lens and the calibration pattern in at least two kinds of positional relationships that are line-symmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens. You may change the relationship.

Preferably, the plurality of images generated by the imaging unit have an overlapping portion between adjacent images, and the plurality of images can cover the entire field of view of the lens. Good .

  It is also effective as a specific aspect of the present invention to express the configuration related to the above invention by replacing it with a calibration method and a calibration device for an imaging apparatus including a lens and an imaging device.

  According to the present invention, it is possible to efficiently calibrate a lens having a large viewing angle such as an equidistant projection optical system and a foveal optical system, or a photographing apparatus including such a lens.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, a calibration method and a calibration apparatus using a calibration pattern will be described. The details of the calibration pattern may be anything. The calibration pattern is, for example, a known lattice pattern composed of lines intersecting at right angles or a checkered pattern composed of right-angled squares.

The calibration pattern may be printed on a paper sheet or a board such as a board, may be projected by a projector, or may be displayed on a display or the like. In the following embodiments, these are collectively referred to simply as “calibration patterns”.
<First Embodiment>
In the first embodiment, a calibration method for an equidistant projection optical system lens (so-called fisheye lens) having a viewing angle of 180 degrees will be described. FIG. 1 shows an example of an image acquired through this lens. The hatched portion in FIG. 1 is a portion where no image information exists.

FIG. 2 is a flowchart showing the flow of lens calibration.
In step S1, the lens and the calibration pattern are arranged at predetermined positions. In the first embodiment, four positional relationships that can acquire four images rotated by 90 degrees around the portion A corresponding to the optical axis are determined in advance. How many positional relationships are arranged may be appropriately determined according to the design value (including the viewing angle) of the lens to be calibrated. By generating two images in at least two positional relationships, an image suitable for calibration can be generated.

In step S1, the lens and the calibration pattern are arranged in a positional relationship where an image corresponding to the region F1 in FIG. 3A can be acquired as the first positional relationship. The image in the region F1 is an image including a viewing angle of (90 + α) degrees in the X and Y directions, as shown in FIG. 3A.
In step S2, an image is generated by the image sensor. As a result, an image of the area F1 in FIG. 3A is generated.

In step S3, it is determined whether or not the generated image covers the entire field of view of the lens. If it is determined that the entire field of view of the lens is covered by the generated image, the process proceeds to step S4.
On the other hand, if it is determined that the entire field of view of the lens is not covered by the generated image, the process returns to step S1, and the lens and the calibration pattern are arranged in the next positional relationship. That is, when the lens and the calibration pattern are arranged in the positional relationship shown in FIG. 3A last time, the lens and the calibration pattern are arranged in the positional relationship capable of acquiring an image corresponding to the region F2 in FIG. 3B. To do. In step S3 (second time), an image of the region F2 in FIG. 3B is generated. Similarly, in step S2 (third time), the lens and the calibration pattern are arranged in a positional relationship where an image corresponding to the region F3 in FIG. 4A can be acquired. In step S3 (third time), FIG. An image of the area F3 is generated. Further, in step S2 (fourth time), the lens and the calibration pattern are arranged in a positional relationship where an image corresponding to the region F4 in FIG. 4B can be acquired, and in step S3 (fourth time), in FIG. An image of the region F4 is generated.

When the four images generated by the four imaging operations described above are overlapped, the entire field of view of the lens can be covered as shown in FIG. Furthermore, the hatched portion in FIG. 5 is an overlapping portion, and the entire field of view of the lens can be completely covered by four images.
In step S4, lens calibration is performed based on the generated four images. Note that the specific method of calibration is the same as that of the known technique, and therefore description thereof is omitted.

  As described above, according to the first embodiment, the calibration pattern is projected through the lens while changing the relative positional relationship between the lens and the calibration pattern according to the viewing angle of the lens. An image is captured a plurality of times to generate a plurality of images. Information necessary for lens calibration is acquired based on a plurality of images. Therefore, even a lens having a large viewing angle such as an equidistant projection optical system and a foveal optical system can be calibrated efficiently.

  Further, according to the first embodiment, a plurality of images are generated while relatively rotating the lens and the calibration pattern with the optical axis of the lens as the rotation axis. Therefore, the lens can be calibrated without bringing the lens and the calibration pattern extremely close to each other or preparing a calibration pattern having a size that can cover the entire field of view. In particular, if the lens and the calibration pattern are extremely close to each other, the calibration will be performed under conditions (such as the distance between the lens and the imaging target) that are significantly different from those when the lens is actually used. For example, calibration can be performed under conditions close to those when an actual lens is used.

Further, according to the first embodiment, the plurality of generated images have an overlapping portion between adjacent images, and the entire field of view of the lens can be covered with the plurality of images. Therefore, even when a plurality of images are used, calibration corresponding to the entire field of view of the lens can be performed.
In addition, in 1st Embodiment, it is good also as a structure which acquires the image of the area | region F5 shown in FIG. 6 in addition to the area | regions F1 to F4 shown in FIG. 3 and FIG. As shown in FIG. 6, the region F5 is a region centered on the portion A corresponding to the optical axis of the lens. Since this portion is very important in the lens, it can be expected to improve the accuracy by acquiring the image of this portion in duplicate and using it for calibration.

Further, by capturing a plurality of images of the same region and generating a plurality of images, information used for calibration can be increased and accuracy can be improved.
In the first embodiment, a lens having a viewing angle of 180 degrees has been described as an example. However, the present invention can be similarly applied to a lens having a viewing angle other than 180 degrees. In any case, the image may be generated in consideration of how many images are generated and how the field of view is covered according to the viewing angle of the lens to be calibrated.

Second Embodiment
In the second embodiment, a lens calibration device will be described. In the second embodiment, a lens having a field of view of 120 degrees in the X direction and a field of view of 80 degrees in the Y direction will be described as an example. FIG. 7 shows an example of an image acquired through this lens.
FIG. 8 is a diagram illustrating a configuration of the calibration apparatus 10 according to the second embodiment. As shown in FIG. 8, the calibration apparatus 10 includes a stage 11 for installing a lens O to be calibrated, an image sensor 12 arranged on a projection plane, a calibration pattern 13, and a calibration pattern 13. The pattern drive unit 14 that drives the image sensor 12, the image sensor 12, and the control unit 15 that controls the pattern drive unit 14 are provided.

The calibration pattern 13 can be rotated around the optical axis A of the lens O (arrow D) by the pattern driving unit 14. That is, the lens O and the calibration pattern 13 are relatively rotatable.
The image sensor 12 is a CCD or the like, and generates an image by capturing an image of the calibration pattern 13 via the lens O. Further, as shown in FIG. 8, the calibration pattern 13 is arranged with an angle δ with respect to the surface B perpendicular to the optical axis A of the lens O.

  When the calibration pattern 13 is arranged parallel to the surface B, in order to cover the entire field of view, the lens O and the calibration pattern 13A are extremely close to each other as shown in 13A of FIG. It is necessary to prepare a calibration pattern 13B having a size that can cover the whole. When the lens O and the calibration pattern 13A are extremely close to each other as shown in 13A, there is a problem of accuracy, a problem that an image of the lens itself appears in the calibration pattern, and the calibration pattern is uniformly illuminated. Problems that are difficult to occur. In addition, when the calibration pattern 13B having a size that can cover the entire field of view is prepared, there are problems such as a large installation location and distortion of the calibration pattern itself accompanying an increase in size. Therefore, in the present embodiment, as shown in FIG. 8, the calibration pattern 13 is arranged with an angle δ with respect to the surface B perpendicular to the optical axis A of the lens O. By arranging in this way, the above-mentioned problems can be solved.

In the calibration apparatus 10 having the configuration described above, the control unit 15 calibrates the lens O as in the first embodiment (see FIG. 2).
In step S1, the control unit 15 arranges the lens O and the calibration pattern 13 at predetermined positions. In the second embodiment, two positional relationships that can acquire two line-symmetric images with a perpendicular perpendicular to the optical axis A as a symmetry axis are determined in advance. How many positional relationships are arranged may be appropriately determined according to the design value (including the viewing angle) of the lens to be calibrated. By generating two images in at least two positional relationships, an image suitable for calibration can be generated.

  In step S1, the control unit 15 controls the pattern driving unit 14 to set the calibration pattern 13 so that an image corresponding to the region F6 in FIG. 10A can be acquired as the first positional relationship. Deploy. The image of the region F6 is an image including a viewing angle of (60 + β) degrees in the X direction and a viewing angle of (80 + γ) degrees in the Y direction, as shown in FIG. 10A.

In step S <b> 2, the control unit 15 generates an image using the image sensor 12. As a result, an image of the area F6 in FIG. 10A is generated.
In step S3, the control unit 15 determines whether or not the generated image covers the entire field of view of the lens. If it is determined that the entire field of view of the lens is covered by the generated image, the process proceeds to step S4.

  On the other hand, if it is determined that the generated image does not cover the entire field of view of the lens, the control unit 15 returns to step S1 and arranges the lens and the calibration pattern in the next positional relationship. That is, when the calibration pattern 13 is arranged in the positional relationship shown in FIG. 10A last time, the calibration pattern 13 is arranged in the positional relationship where an image corresponding to the region F7 in FIG. 10B can be acquired. In step S3 (second time), an image of the region F7 in FIG. 10B is generated.

When the two images generated by the two imaging operations described above are overlapped, the entire field of view of the lens can be covered as shown in FIG. Furthermore, the hatched portion in FIG. 11 is an overlapping portion, and the entire field of view of the lens O can be completely covered by two images.
In step S4, the control unit 15 calibrates the lens O based on the generated two images. Note that the specific method of calibration is the same as that of the known technique, and therefore description thereof is omitted.

  As described above, according to the second embodiment, the change unit that changes the relative positional relationship between the lens and the calibration pattern, and the image obtained by capturing the projection image of the calibration pattern via the lens. And an imaging unit that controls the imaging unit while controlling the changing unit according to the viewing angle of the lens and changing the relative positional relationship between the lens and the calibration pattern. A projected image of the pattern is captured a plurality of times to generate a plurality of images. Information necessary for lens calibration is acquired based on a plurality of images. Further, according to the second embodiment, the plurality of generated images have an overlapping portion between adjacent images, and the entire field of view of the lens can be covered with the plurality of images. Therefore, the same effect as that of the first embodiment can be obtained.

  Further, according to the second embodiment, the changing unit has a relative position between the lens and the calibration pattern in at least two kinds of positional relationships that are line-symmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens. Change the relationship. Therefore, the lens can be calibrated without bringing the lens and the calibration pattern extremely close to each other or preparing a calibration pattern having a size that can cover the entire field of view.

In addition, according to the second embodiment, the calibration pattern is arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens. Therefore, the lens can be calibrated without bringing the lens and the calibration pattern extremely close to each other or preparing a calibration pattern having a size that can cover the entire field of view.
In the second embodiment, an example in which the relative positional relationship between the lens and the calibration pattern is changed to at least two types of positional relationships that are axisymmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens. As shown in the first embodiment, the lens and the calibration pattern may be relatively rotated with the optical axis of the lens as the rotation axis.

On the other hand, in the first embodiment, the optical axis of the lens is a rotational axis, and instead of rotating the lens and the calibration pattern relatively, a perpendicular line perpendicular to the optical axis of the lens is axisymmetrical, and the line is symmetrical. At least two images may be generated.
In the first embodiment, as described in the second embodiment, the calibration pattern may be arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens.

<Third Embodiment>
In the third embodiment, a calibration apparatus for an imaging apparatus will be described. This imaging apparatus includes a fisheye lens similar to that of the first embodiment (see FIG. 1).
FIG. 12 is a diagram illustrating a configuration of the calibration apparatus 20 according to the third embodiment. As shown in FIG. 12, the calibration device 20 includes a stage 23 for installing an imaging device 21 to be calibrated, a calibration pattern 24, a stage driving unit 25 that drives the stage 23, an imaging device 21, and Each part of the control part 26 which controls the stage drive part 25 is provided. As shown in FIG. 12, the imaging device 21 includes a lens P and an imaging element 22 arranged on the projection plane. The imaging element 22 is a CCD or the like, and generates an image by capturing an image of the calibration pattern 24 via the lens P under the control of the control unit 26.

  The stage 23 can be rotated around the optical axis C of the lens P (arrow E) by the stage drive unit 25. That is, the imaging device 21 and the calibration pattern 24 are relatively rotatable. Further, the calibration pattern 24 is arranged with an angle δ with respect to the surface D perpendicular to the optical axis C of the lens P, as in the second embodiment. About this angle, since it is the same as that of 2nd Embodiment, description is abbreviate | omitted.

In the calibration device 20 having the configuration described above, the control unit 26 calibrates the lens P as in the first embodiment (see FIG. 2).
In step S <b> 1, the control unit 26 drives the stage driving unit 25 and arranges the imaging device 21 in a positional relationship in which an image corresponding to the region F <b> 1 in FIG. 3A can be acquired as the first positional relationship.

In step S <b> 2, the control unit 26 controls the imaging element 22 of the imaging device 21 to generate an image. As a result, an image of the area F1 in FIG. 3A is generated.
In step S3, the control unit 26 determines whether or not the generated image covers the entire field of view of the lens. If it is determined that the entire field of view of the lens is covered by the generated image, the process proceeds to step S4.

  On the other hand, if it is determined that the generated image does not cover the entire field of view of the lens, the control unit 26 returns to step S1 and arranges the lens and the calibration pattern in the next positional relationship. That is, when the lens and the calibration pattern are arranged in the positional relationship shown in FIG. 3A last time, the lens and the calibration pattern are arranged in the positional relationship capable of acquiring an image corresponding to the region F2 in FIG. 3B. To do. In step S3 (second time), an image of the region F2 in FIG. 3B is generated. Similarly, in step S2 (third time), the lens and the calibration pattern are arranged in a positional relationship where an image corresponding to the region F3 in FIG. 4A can be acquired. In step S3 (third time), FIG. An image of the area F3 is generated. Further, in step S2 (fourth time), the lens and the calibration pattern are arranged in a positional relationship where an image corresponding to the region F4 in FIG. 4B can be acquired, and in step S3 (fourth time), in FIG. An image of the region F4 is generated.

FIGS. 13A to 13D show the positional relationship between the imaging device 21 and the calibration pattern 24 at the time of four times of imaging.
In step S4, the control unit 26 calibrates the lens based on the generated four images.
As described above, according to the third embodiment, the calibration pattern is projected through the lens while changing the relative positional relationship between the lens and the calibration pattern according to the viewing angle of the lens. An image is captured a plurality of times to generate a plurality of images. Information necessary for lens calibration is acquired based on a plurality of images. Therefore, as in the first embodiment, even a lens having a large viewing angle such as an equidistant projection optical system and a foveal optical system can be calibrated efficiently.

  In the third embodiment, the imaging apparatus 21 including the lens P and the imaging element 22 is described as an example. However, the imaging apparatus 21 does not necessarily have to be completed as an imaging apparatus (camera). . In other words, the calibration may be performed by arranging the lens and the imaging element included in the imaging device at appropriate positions when completed, and arranging them in the same manner as the imaging device 21 of the present embodiment.

In the third embodiment, the example in which the imaging apparatus is calibrated by the calibration apparatus has been described. However, the lens may be calibrated in the same manner as in the first and second embodiments. Conversely, the imaging apparatus may be calibrated by the calibration apparatus described in the second embodiment.
Moreover, you may perform combining a part or all of the technique demonstrated by each embodiment. For example, the technique for rotating the calibration pattern described in the second embodiment may be combined with the technique for rotating the imaging device (calibration target) described in the third embodiment.

It is an example of the image acquired through the equidistance projection optical system lens with a viewing angle of 180 degree | times. It is a flowchart which shows the flow of the calibration of a lens. It is a figure which shows the example of the image produced | generated at the time of calibration. It is another figure which shows the example of the image produced | generated at the time of calibration. It is another figure which shows the example of the image produced | generated at the time of calibration. It is another figure which shows the example of the image produced | generated at the time of calibration. It is an example of an image acquired through a lens having a field of view of 120 degrees in the X direction and a field of view of 80 degrees in the Y direction. It is a figure which shows the structure of the calibration apparatus 10 of 2nd Embodiment. It is a figure explaining angle (delta). It is a figure which shows the example of the image produced | generated at the time of calibration. It is another figure which shows the example of the image produced | generated at the time of calibration. It is a figure which shows the structure of the calibration apparatus 20 of 3rd Embodiment. 3 is a diagram illustrating a positional relationship between the imaging device 21 and a calibration pattern 24. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10,20 ... Calibration apparatus, 11.23 ... Stage, 12.22 ... Image sensor, 13.24 ... Calibration pattern, 15.26 ... Control part

Claims (16)

A method for calibrating a lens using a calibration pattern,
While changing the relative positional relationship between the lens and the calibration pattern according to the viewing angle of the lens, the projected image of the calibration pattern through the lens is captured a plurality of times to obtain a plurality of An imaging process for generating an image;
E Bei and an acquisition step of acquiring the information required for calibration of the lens based on the plurality of images,
In the imaging step, the calibration pattern is arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens. The lens calibration method according to claim 1,
In the imaging step, the plurality of images are generated while relatively rotating the lens and the calibration pattern with the optical axis of the lens as a rotation axis. The lens calibration method according to claim 1,
In the imaging step, at least two images that are line symmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens are generated. In the lens calibration method according to any one of claims 1 to 3,
The plurality of images generated by the imaging step have an overlapping portion between adjacent images, and the plurality of images can cover the entire field of view of the lens. Calibration method. A lens calibration device using a calibration pattern,
A changing unit that changes a relative positional relationship between the lens and the calibration pattern;
An imaging unit that captures a projection image of the calibration pattern via the lens and generates an image;
According to the viewing angle of the lens, the changing unit is controlled to change the relative positional relationship between the lens and the calibration pattern, and the imaging unit is controlled to project the calibration pattern. A control unit that captures an image a plurality of times and generates a plurality of images;
E Bei and an acquisition unit for acquiring information necessary for the calibration of the lens based on the plurality of images,
The lens calibration apparatus, wherein the calibration pattern is arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens. The lens calibration device according to claim 5 ,
The lens calibration apparatus, wherein the changing unit relatively rotates the lens and the calibration pattern with the optical axis of the lens as a rotation axis. The lens calibration device according to claim 5 ,
The changing unit changes a relative positional relationship between the lens and the calibration pattern into at least two types of the positional relationships that are line symmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens. Lens calibration device characterized by the above. The lens calibration device according to any one of claims 5 to 7 ,
The plurality of images generated by the imaging unit have an overlapping portion between adjacent images, and the plurality of images can cover the entire field of view of the lens. Calibration device. A calibration method using a calibration pattern, which relates to an imaging device including a lens and an imaging device,
According to the viewing angle of the lens, a plurality of projection images of the calibration pattern through the lens are projected by the imaging element while changing the relative positional relationship between the imaging device and the calibration pattern. An imaging step of generating a plurality of images by performing imaging once;
E Bei and an acquisition step of acquiring the information required for calibration of the imaging device based on the plurality of images,
In the imaging step, the calibration pattern is arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens . In the calibration method of the imaging device according to claim 9 ,
In the imaging step, the imaging device generates the plurality of images while relatively rotating the imaging device and the calibration pattern with the optical axis of the lens as a rotation axis. Calibration method. In the calibration method of the imaging device according to claim 9 ,
In the imaging step, at least two images that are axisymmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens are generated. In the calibration method of the imaging device according to any one of claims 9 to 11 ,
The plurality of images generated by the imaging step have an overlapping portion between adjacent images, and the plurality of images can cover the entire field of view of the lens. Calibration method. A calibration device using a calibration pattern, which relates to an imaging device including a lens and an imaging device,
A changing unit that changes a relative positional relationship between the imaging device and the calibration pattern;
According to the viewing angle of the lens, the changing unit is controlled to change the relative positional relationship between the imaging device and the calibration pattern, and to control the imaging element to control the calibration pattern. A control unit that captures a projected image a plurality of times and generates a plurality of images;
E Bei and an acquisition unit for acquiring information necessary for the calibration of the imaging device based on the plurality of images,
The calibration apparatus for an imaging apparatus, wherein the calibration pattern is arranged with a predetermined angle with respect to a plane perpendicular to the optical axis of the lens . In the calibration device of the imaging device according to claim 13 ,
The changing unit relatively rotates the imaging device and the calibration pattern about the optical axis of the lens as a rotation axis. In the calibration device of the imaging device according to claim 13 ,
The changing unit changes a relative positional relationship between the imaging device and the calibration pattern into at least two types of positional relationships that are line symmetric with respect to a perpendicular line that is orthogonal to the optical axis of the lens. A calibration apparatus for an image pickup apparatus. In the calibration device of the imaging device according to any one of claims 13 to 15 ,
The plurality of images generated by the image sensor have an overlapping portion between adjacent images, and the plurality of images can cover the entire field of view of the lens. Calibration equipment.

Images