主权项 |
1. A computer implemented method of determining extrinsic parameters for a vehicle vision system, the method comprising:
processing an image of a road captured by a camera to identify a first road lane marking and a second road lane marking in the image, where the first road lane marking and the second road lane marking are two road lane markings that extend parallel to each other; determining, for at least one of the two road lane markings:
a first set of parameters defining an orientation and a position of a line along which the at least one of the two road lane markings extends in an image plane, where the determining the first set of parameters comprises determining parameter values a′i, b′i and c′i, such that the line along which the at least one of the two road lane markings extends in the image plane is defined by
a′i·x′+b′i·y′+c′i=0, where i denotes a road lane marking identifier and x′ and y′ denote coordinates in the image plane; anda second set of parameters defining an orientation and a position of a line along which the at least one of the two road lane markings extends in a road plane, where the second set of parameters is determined based on information related to spacing of the two road lane markings, wherein at least one of the first set of parameters and the second set of parameters includes coefficients of a bilinear equation; identifying a linear transformation which, for at least one of the two road lane markings, defines a mapping between the first set of parameters and the second set of parameters, where the identifying the linear transformation comprises determining matrix elements of a homographs matrix; and establishing the extrinsic parameters based on the identified linear transformation, where the established extrinsic parameters include an orientation of the camera with respect to a vehicle coordinate system. |