I’m attempting to calibrate my camera using the OpenCV method in Python, as outlined in this documentation:

https://docs.opencv.org/4.x/dc/dbb/tutorial_py_calibration.html.

However, when I attempt to undistort my images, they appear more distorted than the originals.

These are three of the image I used for the calibration :

Image calibration 1

Image calibration 13

Image calibration 8

Image before undistortion :

Image before undistortion

Image after undistortion :

image undistorded

In addition, how can I have my coordinates directly in mm ?

I was expecting an improvement on the precision of my pictures.

Thank you in advance for your answers it will be very helpful

Best regards