Open cv stereo calibration with FOH 120°, getting "bad" rms
I'm currently working on a Project in which I have to calibrate a pair of cameras to rectify the images for a stream.
For the calibration I'm using a chessboard pattern.
I'm doing the calibration by following those steps:
- I calibrate the master and slave camera independently with 30 images and save the intrinsics and extrinsics
- Then I do the stereo calibration on both cameras using 10 images and feeding the intrinsics found by mono calibration.
Now the results I get are not really satisfying. Rms from mono calibration is in the range from 1.2 to 5 and the rms from the stereo calibration is in the range from 1.7 to 3.
What confuses me is the fact that opencv has a namespace for fisheye calibration but I'm not sure if I should use that because my cameras are not fisheye but wide angle. I tried to set a lot of different flags in the cv::calibrate and cv::stereoCalibrate functions but that didn't lead me to a satisfying output.
Has anyone some experience in this field? Id be happy to share some code but I would need to know what part of it would be interesting, because I implemented it in a custom gstreamer plugin which makes it difficult to just share the whole code.