Patent ID: 11861812
Assignee: NEC CORPORATION
Field: Audio-visual technology (Electrical engineering)
Classification: CPC G  H | IPC G  H

Claim 4:
5. A non-transitory computer-readable recording medium storing a program that is executable by a processor to perform processing for estimating a geometric parameter of a camera that has shot an image of an object and a lens distortion parameter of a lens distortion model represented by a single unknown, the processing comprising:
obtaining image corresponding points relating to the object and an approximation order for polynomial approximation of the lens distortion model;
estimating the geometric parameter and the lens distortion parameter based on the image corresponding points and the approximation order, by:
estimating a plurality of candidates for the geometric parameter and a plurality of candidates for the lens distortion parameter based on the image corresponding points and the approximation order; and
selecting the geometric parameter candidate and the lens distortion parameter candidate that minimize an error function that represents a transformation relation between the image corresponding points and the geometric parameter and the lens distortion parameter,

wherein when a number of the image corresponding points does not meet a set condition, the geometric parameter candidate and the lens distortion parameter candidate that minimize the error function through non-linear optimization are selected.