Merge pull request opencv#19539 from asmorkalov:as/calib_fix_focal_le…

…ngth

* Added CALIB_FIX_FOCAL_LENGTH to fisheye calibration opencv#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.

Merge pull request opencv#19539 from asmorkalov:as/calib_fix_focal_le…

…ngth

* Added CALIB_FIX_FOCAL_LENGTH to fisheye calibration opencv#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.

OpenCV 4.5.1

OpenCV 3.4.13

OpenCV 4.5.1 for Intel(R) OpenVINO(TM) toolkit

OpenCV 4.5.0

OpenCV 3.4.12

OpenCV 4.5.0 for Intel(R) OpenVINO(TM) toolkit

OpenCV 4.4.0

OpenCV 3.4.11