Hi, In itkMultithreader.h there is a #define ITK_MAX_THREADS=32 for most platforms. Is this a limit imposed by the OS or by ITK? If the latter, can we raise this value or not restrict at all? Josh. ______________________________ Josh Cates School of Computer Science University of Utah Email: cates@sci.utah.edu Phone: (801) 587-7697 URL: http://www.sci.utah.edu/~cates