I was wondering how to verify the mag_distortion_correction result.
I did mag distortion estimation on an original image and the results were:
distortion angle 42.0
major scale 1.015
minor scale 0.985
total distortion 2.97%
stretch only parameters: 42 / 1.03 / 1 / 0.626
After doing mag distortion correction with the stretch only parameters, I did mag distortion estimation again on the corrected image, and the results were:
distortion angle 42.2
major scale 1.007
minor scale 0.993
total distortion 1.40%
stretch only parameters: 42 / 1.014 / 1 / 0.622
Also the pixel size (from the header info) of the corrected image shows 0.1348E-03 for x and 0.1303E-03 for y, which I assume should be 0.626.