public class RadialDistortionEstimateLinear extends Object
Estimates radial lens distortion by solving a linear equation with observed features on a calibration grid. Typically used as an initial estimate for use in non-linear optimization. An arbitrary number of distortion parameters can be solved for, but typically only two are found. The estimated is computed using a known intrinsic camera matrix,and homographies relating grid to camera coordinates. Based upon the description found in Section 3.3 in .
Radial distortion is modeled using the following equations:
u' = u + (u - u0)*[ k1(x2 + y2) +k2(x2 + y2)2]
v' = v + (v - v0)*[ k1(x2 + y2) +k2(x2 + y2)2]
where (u',v') is the observed distortion in pixel coordinates, (u0,v0) is the image center in pixel coordinates, (x,y) is the predicted distortion free calibrated coordinates.
The algorithm works by solving the system of equations below:
[ (u-u0)*r2 , (u-u0)*r4 ][k1] = [u'-u]
[ (v-v0)*r2 , (v-v0)*r4 ][k2] = [v'-v]
where r2 = (x2+y2).
 Zhengyou Zhang, "Flexible Camera Calibration By Viewing a Plane From Unknown Orientations," 1999
RadialDistortionEstimateLinearCreates a estimator for the specified number of distortion parameters.
layout- Description of calibration grid
numParam- Number of radial distortion parameters. Two is a good number.
processpublic void process(DMatrixRMaj cameraCalibration, List<DMatrixRMaj> homographies, List<CalibrationObservation> observations)Computes radial distortion using a linear method.
cameraCalibration- Camera calibration matrix. Not modified.
observations- Observations of calibration grid. Not modified.
getParameterspublic double getParameters()Returns radial distortion parameters.
- radial distortion parameters.