| CPC G01B 11/2504 (2013.01) [G03B 21/208 (2013.01); G06T 7/80 (2017.01); H04N 23/56 (2023.01); G03B 21/2013 (2013.01)] | 27 Claims |
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1. A method for calibrating a detector comprising at least one camera and at least one projector, wherein the at least one projector is configured for illuminating at least one target with at least one predefined illumination pattern comprising a plurality of illumination features, wherein the camera has at least one sensor element having a matrix of optical sensors, the optical sensors each having a light-sensitive area, wherein each optical sensor is designed to generate at least one sensor signal in response to an illumination of its respective light-sensitive area by a light beam propagating from the target to the camera, wherein the target comprises at least one first target and at least one second target, wherein the first target and the second target have a predefined fixed relative distance, wherein the target is positioned at a pre-defined distance from the detector, wherein the method comprises the following steps:
a) illuminating the first target with a first part of the illumination pattern and illuminating the second target with a second part of the illumination pattern by using the projector, wherein the first and second part of the illumination pattern differ, and imaging by using the camera at least one combined reflection image of the illuminated first target and the illuminated second target, wherein the combined reflection image comprises a plurality of first reflection features generated by the first target in response to the first part of the illumination pattern and a plurality of second reflection features generated by the second target in response to the second part of the illumination pattern;
b) splitting the combined reflection image into a first reflection image and a second reflection image by using at least one evaluation device of the detector, wherein the first reflection image comprises the first reflection features and the second reflection image comprises the second reflection features;
c) for the first reflection image, reconstructing by using the evaluation device missing reflection features relating to the second part of the illumination pattern using the predefined illumination pattern, and, for the second reflection image, reconstructing by using the evaluation device missing reflection features relating to the first part of the illumination pattern using the predefined illumination pattern;
d) determining by using the evaluation device a first reconstructed image by adding the reconstructed reflection features relating to the second part of the illumination pattern to the first reflection image and determining by using the evaluation device a second reconstructed image by adding the reconstructed reflection features relating to the first part of the illumination pattern to the second reflection image;
e) evaluating the first reconstructed image and the second reconstructed image by using the evaluation device, wherein the evaluation comprises
e1) matching reflection features of the first reconstructed image to reflection features of the second reconstructed image considering the predefined distance of the target and the predefined fixed relative distance of the first target and the second target thereby determining pairs of matched reflection features; and
e2) determining an epipolar line for each of the pairs of the matched reflection features, wherein the respective matched reflection features lie on the epipolar line; and
f) determining at least one extrinsic calibration information of the detector using the determined epipolar lines by using the evaluation device.
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