In my last question I asked about SIFT and SURF implementation in MATLAB source codes and several links were received. Thanks for all. Now, I have another question. These SIFT implementations are like libraries that we are using (for an example when coding c++ programming, we are including iostream library. But we don't have to change any code which is inside that library) right?. So, I can just use these SIFT implementations as a library and do not need to change any code for my images right? That means sift implementation is working for any image? Can someone please help me?
VLFeat is a C library, that you can use from C++ (without changing the library). The images have to be stored as one float per pixel. You can read the C API documentation here: http://vlfeat.org/api/sift_8h.html