Notoriously poor coding by the OpenCV group here, with trackbars being barely functional.
The two main issues are:
- Trackbar value is not displayed
- Trackbar ordering is not the same as the order in which they are coded
- In fact is is apparently random, or pseudo-random – it is a logic, but it is not clear what that logic is
Additional issues are:
- Named windows containing only trackbars do not move with
- Named windows containing only trackbars do not resize with
resizeWindow()– check this!!!
- Code execution pauses when a trackbar is adjusted
- Performance hits
- When trackbars are in the same window as the image being adjusted
I have seen these issues consistently in Python. I am not sure if they all occur in C++ as I haven’t tested for them (yet).
- OS X: High Sierra
- Python 3.7/3.9