Calibration device, calibration method, and non-transitory computer-readable storage medium for the same
First Claim
1. A calibration device identifying attitude parameters of a plurality of cameras mounted to a vehicle, wherein:
- the plurality of cameras are mounted to the vehicle so as to capture images of specified regions different from each other and defined around the vehicle, each specified region having overlap regions where the specified region partially overlap with another specified region;
the plurality of cameras include a first camera capturing an image in a forward direction of the vehicle, a second camera capturing an image in a rightward direction of the vehicle, a third camera capturing an image in a rearward direction of the vehicle, and a fourth camera capturing an image in a leftward direction of the vehicle;
the calibration device comprises;
an image acquisition unit acquiring images captured by the plurality of cameras;
a first identification unit acting on imaging targets with given shape and size to perform projective transformation for the imaging targets shown in the overlap regions of each image acquired by the image acquisition unit and identify a roll, a pitch and a vertical position among the attitude parameters of each of the plurality of cameras so that conversion results are consistent with the shape and size of the imaging target, the roll being a rotation angle of each camera about a lens center axis of the camera, the pitch being a rotation angle of each camera about a horizontal axis of the camera, the vertical position being a coordinate in a height direction of the vehicle; and
a second identification unit acting on a virtual link structure to identify an x-coordinate, a y-coordinate and a yaw among the attitude parameters of each of the plurality of cameras so that one link angle of the virtual link structure is minimized, the x-coordinate being a coordinate in a longitudinal direction of the vehicle, the y-coordinate being a coordinate in a lateral direction of the vehicle, the yaw being a rotation angle of the vehicle about an axis perpendicular to a horizontal plane, the virtual structure being formed of line segments serving as links and virtually connecting representative points of the imaging targets shown in the images acquired by the image acquisition unit, where the representative points of the imaging targets located at the same position and shown in the overlap regions of different images are permitted to coincide with each other;
the image acquisition unit comprises;
a first acquisition unit acquiring images of the imaging targets ahead of the vehicle captured by the first camera, the second camera, and the fourth camera; and
a second acquisition unit acquiring images of the imaging targets behind the vehicle captured by the second camera, the third camera, and the fourth camera, these images being different from the images acquired by the first acquisition unit;
andthe first identification unit and the second identification unit use images acquired by the first acquisition unit and images acquired by the second acquisition unit, as images acquired by the image acquisition unit to identify attitude parameters of each of the plurality of cameras.
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Accused Products
Abstract
A calibration device acquires an image of an imaging target located ahead of a vehicle. Images of the imaging targets behind the vehicle are acquired, which are different from the acquired images captured in the forward direction. The shape and size of the imaging targets are already known. The calibration device performs projective transformation for the imaging targets shown in overlap regions of the acquired images, and identifies a roll, a pitch and a vertical position of each camera such that the conversion results are in agreement with the shape and size of the targets. The calibration device identifies an x-coordinate, a y-coordinate, and a yaw of each camera such that one link angle in a virtual link structure is minimized.
12 Citations
9 Claims
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1. A calibration device identifying attitude parameters of a plurality of cameras mounted to a vehicle, wherein:
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the plurality of cameras are mounted to the vehicle so as to capture images of specified regions different from each other and defined around the vehicle, each specified region having overlap regions where the specified region partially overlap with another specified region; the plurality of cameras include a first camera capturing an image in a forward direction of the vehicle, a second camera capturing an image in a rightward direction of the vehicle, a third camera capturing an image in a rearward direction of the vehicle, and a fourth camera capturing an image in a leftward direction of the vehicle; the calibration device comprises; an image acquisition unit acquiring images captured by the plurality of cameras; a first identification unit acting on imaging targets with given shape and size to perform projective transformation for the imaging targets shown in the overlap regions of each image acquired by the image acquisition unit and identify a roll, a pitch and a vertical position among the attitude parameters of each of the plurality of cameras so that conversion results are consistent with the shape and size of the imaging target, the roll being a rotation angle of each camera about a lens center axis of the camera, the pitch being a rotation angle of each camera about a horizontal axis of the camera, the vertical position being a coordinate in a height direction of the vehicle; and a second identification unit acting on a virtual link structure to identify an x-coordinate, a y-coordinate and a yaw among the attitude parameters of each of the plurality of cameras so that one link angle of the virtual link structure is minimized, the x-coordinate being a coordinate in a longitudinal direction of the vehicle, the y-coordinate being a coordinate in a lateral direction of the vehicle, the yaw being a rotation angle of the vehicle about an axis perpendicular to a horizontal plane, the virtual structure being formed of line segments serving as links and virtually connecting representative points of the imaging targets shown in the images acquired by the image acquisition unit, where the representative points of the imaging targets located at the same position and shown in the overlap regions of different images are permitted to coincide with each other; the image acquisition unit comprises; a first acquisition unit acquiring images of the imaging targets ahead of the vehicle captured by the first camera, the second camera, and the fourth camera; and a second acquisition unit acquiring images of the imaging targets behind the vehicle captured by the second camera, the third camera, and the fourth camera, these images being different from the images acquired by the first acquisition unit; and the first identification unit and the second identification unit use images acquired by the first acquisition unit and images acquired by the second acquisition unit, as images acquired by the image acquisition unit to identify attitude parameters of each of the plurality of cameras. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A calibration method performed by a calibration device identifying attitude parameters of a plurality of cameras mounted to a vehicle, wherein:
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the plurality of cameras are mounted to the vehicle so as to capture images of specified regions different from each other and defined around the vehicle, each specified region having overlap regions where the specified region partially overlap with another specified region; the plurality of cameras include a first camera capturing an image in a forward direction of the vehicle, a second camera capturing an image in a rightward direction of the vehicle, a third camera capturing an image in a rearward direction of the vehicle, and a fourth camera capturing an image in a leftward direction of the vehicle; the calibration method comprises; an image acquisition step of acquiring images captured by the plurality of cameras; a first identification step of acting on imaging targets with given shape and size to perform projective transformation for the imaging targets shown in the overlap regions of each image acquired by the image acquisition step and identify a roll, a pitch and a vertical position among the attitude parameters of each of the plurality of cameras so that conversion results are consistent with the shape and size of the imaging target, the roll being a rotation angle of each camera about a lens center axis of the camera, the pitch being a rotation angle of each camera about a horizontal axis of the camera, the vertical position being a coordinate in a height direction of the vehicle; and a second identification step of acting on a virtual link structure to identify an x-coordinate, a y-coordinate and a yaw among the attitude parameters of each of the plurality of cameras so that one link angle of the virtual link structure is minimized, the x-coordinate being a coordinate in a longitudinal direction of the vehicle, the y-coordinate being a coordinate in a lateral direction of the vehicle, the yaw being a rotation angle of the vehicle about an axis perpendicular to a horizontal plane, the virtual structure being formed of line segments serving as links and virtually connecting representative points of the imaging targets shown in the images acquired by the image acquisition step, where the representative points of the imaging targets located at the same position and shown in the overlap regions of different images are permitted to coincide with each other; the image acquisition step comprises; a first acquisition step of acquiring images of the imaging targets ahead of the vehicle captured by the first camera, the second camera, and the fourth camera; and a second acquisition step of acquiring images of the imaging targets behind the vehicle captured by the second camera, the third camera, and the fourth camera, these images being different from the images acquired by the first acquisition step; and the first identification step and the second identification step use images acquired through the first acquisition step and images acquired through the second acquisition step, as images acquired by the image acquisition step to identify attitude parameters of each of the plurality of cameras.
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9. A non-transitory computer-readable storage medium containing thereon a program comprising instructions, causing a computer to execute a display control method for identifying attitude parameters of a plurality of cameras mounted to a vehicle by a calibration device, wherein:
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the plurality of cameras are mounted to the vehicle so as to capture images of specified regions different from each other and defined around the vehicle, each specified region having overlap regions where the specified region partially overlap with another specified region; the plurality of cameras include a first camera capturing an image in a forward direction of the vehicle, a second camera capturing an image in a rightward direction of the vehicle, a third camera capturing an image in a rearward direction of the vehicle, and a fourth camera capturing an image in a leftward direction of the vehicle; the computer is permitted to function as; an image acquisition step of acquiring images captured by the plurality of cameras; a first identification step of acting on imaging targets with given shape and size to perform projective transformation for the imaging targets shown in the overlap regions of each image acquired by the image acquisition step and identify a roll, a pitch and a vertical position among the attitude parameters of each of the plurality of cameras so that conversion results are consistent with the shape and size of the imaging target, the roll being a rotation angle of each camera about a lens center axis of the camera, the pitch being a rotation angle of each camera about a horizontal axis of the camera, the vertical position being a coordinate in a height direction of the vehicle; and a second identification step of acting on a virtual link structure to identify an x-coordinate, a y-coordinate and a yaw among the attitude parameters of each of the plurality of cameras so that one link angle of the virtual link structure is minimized, the x-coordinate being a coordinate in a longitudinal direction of the vehicle, the y-coordinate being a coordinate in a lateral direction of the vehicle, the yaw being a rotation angle of the vehicle about an axis perpendicular to a horizontal plane, the virtual structure being formed of line segments serving as links and virtually connecting representative points of the imaging targets shown in the images acquired by the image acquisition step, where the representative points of the imaging targets located at the same position and shown in the overlap regions of different images are permitted to coincide with each other; the image acquisition step comprises; a first acquisition step of acquiring images of the imaging targets ahead of the vehicle captured by the first camera, the second camera, and the fourth camera; and a second acquisition step of acquiring images of the imaging targets behind the vehicle captured by the second camera, the third camera, and the fourth camera, these images being different from the images acquired by the first acquisition step; and the first identification step and the first identification step use images acquired by the first acquisition step and images acquired by the second acquisition step, as images acquired by the image acquisition step to identify attitude parameters of each of the plurality of cameras.
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Specification