ofxCv calibration artifacts

i am using ofxCv calibration and seeing artifacts in the undistorted images.
am i doing something wrong?

my settings.yml is set to 7x10 with 2.2cm squares.
i am using an A4 piece of paper.

thanks for any advise.

I’d recommend to use a more rigid support than a cardboard, maybe a thin piece of wood? The surface should be as planar as possible.

thanks for the tip.
tried it, but still seems to have those artifacts

stillt he same problem


use OF 0.9.8

fix this bug
https://github.com/kylemcdonald/ofxCv/issues/175

replace inside Calibartion.cpp
// int calibFlags = 0;
int calibFlags =CV_CALIB_FIX_PRINCIPAL_POINT | CV_CALIB_ZERO_TANGENT_DIST | CV_CALIB_FIX_FOCAL_LENGTH | CV_CALIB_FIX_ASPECT_RATIO | CV_CALIB_FIX_K3 | CV_CALIB_FIX_K4 | CV_CALIB_FIX_K5 | CV_CALIB_FIX_K6;