Emgu CV Library Documentation
extended Field
NamespacesEmgu.CV.StructureMCvSURFParamsextended

www.emgu.com/wiki
0 means basic descriptors (64 elements each), 1 means extended descriptors (128 elements each)
Declaration Syntax
C#Visual BasicVisual C++
public int extended
Public extended As Integer
public:
int extended

Assembly: Emgu.CV (Module: Emgu.CV) Version: 1.5.0.0 (1.5.0.0)