Hi, actually OpenCV 2.4.5 supports only one method (Otsu) for automatic global thresholding, but many more of them exist and their source is freely available from here: Auto Threshold methods
Some of them are useful for microscopy image segmentation, while others are better suited for other situations with uneven illumination, so I think it would be an useful addition for OpenCV and the implementation is straightforward since the provided source code is Java code converted from C++.
Best regards,
Guido
