Northstar calibration script

[WarrenTheApe]

I am trying to calibrate my north star using the calibration rig and NorthstarCalibrator software. Following the steps in the ReadMe I've installed Python and pip installed numpy and openCV-python. Using the printed-out chessboard and running the script it appears that I am getting pretty good (straight lines no distortion) results in the 4 window display. However, only the .npz file and not the .json file are being saved to the main folder. I don't know why... plesse help. Respectfully, Warren The Ape

[jselstad]

Run the calibration script a second time with the .npz in your folder, and it should create a .json (and show you a preview of loaded the calibration as well).

It could also your OS's read/write permissions changed between the first and second running. Worst case scenario, you can post your .npz here and we can send you a .json.

[WarrenTheApe]

Hi Jselstad,

When I run dualStereoChessboardCalibration.py it copies the npz to the main folder. Here's a clue to the crime: The Python code doesn't seem to complete. I get the message "Dual Stereo Camera Calibration Completed and Saved".The program seems to stop there so I have to Control C out. This makes running the program a second time impossible. I don't see how to attach my .npz so I will attach it to an email. If you can create the .json from it that would be great. If you have any ideas from the above info, I real curious...

Thanks again,
Warren The Ape

[fmaurer]

You've done everything correct. Simply run the python script again. If dualStereoChessboardCalibration.py finds the file "dualCameraCalibration.npz" then it exports the json file. Otherwise it'll output text: "No calibration file found" and tries to create a new npz. If the calibration is bad, you can simple delete the "dualComeraCalibration.npz" file to try again.

[WarrenTheApe]

Hi fmaurer,
When I run the python script a second time I get this message and no ,json is exported:

Traceback (most recent call last):
File ".\dualStereoChessboardCalibration.py", line 84, in
writeCalibrationJson(calibrations)
File ".\dualStereoChessboardCalibration.py", line 26, in writeCalibrationJson
"baseline": float(calibration[0]["leftToRightTrans"][0])+-1.0,
TypeError: 'NoneType' object is not subscriptable

[WarrenTheApe]

Is there an email address that I can use to send the .npz file? I'd like to take you up on your offer to convert it since I cannot using the calibration technique.

Thanks,
Warren Ape

[AlexColgan]

Following up via email.