| CPC G06T 7/80 (2017.01) [G01T 7/005 (2013.01); G06T 2207/10081 (2013.01); G06T 2207/20072 (2013.01); G06T 2207/30204 (2013.01)] | 18 Claims |
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1. A geometric calibration apparatus comprising:
a memory configured to store one or more instructions; and
a processor configured to, by executing the one or more instructions:
detect a plurality of first points from a plurality of projection regions, respectively, a plurality of first markers disposed on a phantom being projected onto the projection regions in two dimensions by a computer tomography device;
calculate an output vector representing a probability distribution that gives a probability with which each of the first points is a projection of each of the first markers, by inputting data corresponding to each of the first points to a learning model;
extract a predetermined number of first samples based on the probability distribution;
obtain a candidate projection matrix by transforming correspondences between second markers determined based on the first samples among the first markers and second points determined based on the first samples among the first points;
calculate third points into which the first markers are transformed by the candidate projection matrix;
calculate a difference between a first set of the third points and a second set of the first points; and
designate the candidate projection matrix as a projection matrix in response to the difference being less than or equal to a threshold.
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