Hi folks,
I just changed from OpenCV 2.2.0 to 2.4.5 and what I observe is CvEM (expectation maximization) speed dropping by a factor of 7. Searching around a bit, I found this bug report:
http://code.opencv.org/issues/1435
but that or the one it links to has not been updated for a while. I see that CvEM has been moved to legacy code, but nevertheless the problem appears to be not using LAPACK at all. BTW, is cv::EM just a wrapper around CvEM?
I just wonder if there would be a solution. At least I think it is good to raise this issue.
For my case, time increase (to put in numbers: from 3 to 21 seconds) is not acceptable. At time, I plan to put the few new 2.4.5. features that I need into a DLL, and continue using 2.2.0 for my actual project.
I have compiled both 2.2.0 and 2.4.5 from source using Visual C++ 9.0, and configured the project hand picking every single CMake option. I suppose there shouldn't be any config issue. I don't have EIGEN2 (which was already an option in 2.2.0), and I'm using Win XP 32-bit (Intel Core i5 Arrandale).