dAB              1588 modules/calib3d/src/fisheye.cpp     dAB(R2, R1, dR3dR2, dR3dR1);
dAB              1600 modules/calib3d/src/fisheye.cpp     dAB(R2, T1, dT3tdR2, dT3tdT1);
dAB                47 modules/calib3d/src/fisheye.hpp void dAB(cv::InputArray A, InputArray B, OutputArray dABdA, OutputArray dABdB);