Hi there!
After watching the images here are my comments:
- I see that you posted JPG files, I don't know if those are the original files you used, but whenever possible use raw images (not compressed, as compression generates artifacts that affect the ability of detecting the corners of the chessboard)
- The size of the squares might be too small in relation to the resolution of your camera. How about using bigger squares?
- This is not related to corner detection, but I see that you are using a 16x16 chessboard. I would recommend you to use a non-square chessboard (16x15, for example), this way the orientation of the chessboard can be uniquely determined. Otherwise you can get strange effects on the calibration.
I hope this helps
