* Added CALIB_FIX_FOCAL_LENGTH to fisheye calibration #13450
Sometimes you want to calibrate just the principal point of a camera, or just the distortion coefficients. In this case, you can pass the CALIB_FIX_FOCAL_LENGTH flag to keep Fx and Fy
* Added test for CALIB_FIX_FOCAL_LENGTH option in fisheye callinration.
Fisheye test has been updated to use new enum cv::fisheye::CALIB_ZERO_DISPARITY and included CV_StaticAssert(...) to ensure cv::CALIB_ZERO_DISPARITY == cv::fisheye::CALIB_ZERO_DISPARITY.
fix instable fisheye undistortPoints
* remove artefacts when (un)distorting fisheye images with large distortion coefficient values
* fix fisheye undistortion when theta is close to zero
* add fisheye image undistort and distort test
* Fixed type conversion warnings
* fixed trailing whitespace
- removed tr1 usage (dropped in C++17)
- moved includes of vector/map/iostream/limits into ts.hpp
- require opencv_test + anonymous namespace (added compile check)
- fixed norm() usage (must be from cvtest::norm for checks) and other conflict functions
- added missing license headers