Chessboard detection fails on fisheye image
I am trying to perform calibration for a fisheye lens using the omnidir module. I am finding that the chessboards are not detected on many of the calibration images.
For example, here is an image that it fails on. Why would this be? it has no occlusion and good lighting. I also tried downsampling to half the resolution as I heard that might help. Using opencv3-3.1.0_3 on OSX.
EDIT: After recompiling with DEBUG_CHESSBOARD enabled, I found that the issue was caused by the new binarization failing. The debug output shows what the old binarization algorithm would have given, and it's clear that the old algorithm gave the correct result.
Old binarization:
New binarization:
This seems like a bug in opencv, so I will report it.
Omnidir is for a pinhole camera not fisheye. You should use http://docs.opencv.org/master/db/d58/...
No omnidir is for fisheye as well, as per the documentation: http://docs.opencv.org/trunk/dd/d12/t.... In any case chessboard detection is independent of the calibration and just depends on the raw image.
with image given may be you can have problem with this
Enabling DEBUG_CHESSBOARD shows that the binarization is failing. In fact, the old binarization work, but the new binarization fails. I have added example images to the question