I couldnt use the library that I have already imported as references in my project

I am writing a program for computer vision in c# that part of project SIFT is needed; I downloaded the MEMO library for SIFT :

http://www.nowozin.net/sebastian/tu-berlin-2006/libsift/

In my project I added the two libraries ****libsift.dll & ICSharpCode.SharpZipLib.dll** ** as references in to my projects.

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Now that I want to mention libsift on top of the code " USING libsift" it doesnt recognize it;

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even more if I wanna make a instance of such class atuo detect doesn't recognize it.

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It is weird because I could see the functions of this library in object browser.

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I couldnt use the library that I have already imported as references in my project although I could see the functions in object browser? What could be the problem?

(I have c# .Net VS2010 in windows.)

Solution

It looks like they're in the root namespace - not in a namespace called libsift. If that is the case, you don't need a using libsift; directive - just try accessing Keypoint etc directly. Or possibly global::Keypoint. It should be noted that dumping types into the root namespace is frowned upon - it makes it hard to avoid conflicts. But that is the fault of libsift.

The other possibility is that you've changed the "Aliases" property on the reference; that should be "global". You can see this in the property panel when you select an individual reference in the solution explorer - alongside things like "Copy Local", "Specific Version", etc. If it is anything else: change it back to "global", or learn about extern aliases.

Tested locally (the types are in the global namespace):

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