opencv2.4.5正确调用SurfFeatureDetector，SiftFeatureDetector

在以前版本中，surf和sift算法都是在头文件#include <opencv2/features2d/features2d.hpp>中，但在新的opencv版本出来后，如果仍然使用这个头文件就会出现编译错误如下：

1>  interestPoints.cpp
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(135): error C2039: 'SurfFeatureDetector' : is not a member of 'cv'
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(135): error C2065: 'SurfFeatureDetector' : undeclared identifier
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(135): error C2146: syntax error : missing ';' before identifier 'surf'
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(135): error C3861: 'surf': identifier not found
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(137): error C2065: 'surf' : undeclared identifier
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(137): error C2228: left of '.detect' must have class/struct/union
1>          type is ''unknown-type''
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(151): error C2039: 'SiftFeatureDetector' : is not a member of 'cv'
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(151): error C2065: 'SiftFeatureDetector' : undeclared identifier
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(151): error C2146: syntax error : missing ';' before identifier 'sift'
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(151): error C3861: 'sift': identifier not found
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(157): error C2065: 'sift' : undeclared identifier
1>d:\visual studio 2010\exercises\opencv2\myinterestpoints\interestpoints.cpp(157): error C2228: left of '.detect' must have class/struct/union
1>          type is ''unknown-type''
1>
1>Build FAILED.

产生错误的原因就是 sift 和 surf算法已经写到#include <opencv2/nonfree/features2d.hpp>中，所以需要把头文件替换一下， 然后又回出现错误：

1>  All outputs are up-to-date.
1>interestPoints.obj : error LNK2019: unresolved external symbol "public: __thiscall cv::SIFT::SIFT(int,int,double,double,double)" (??0SIFT@cv@@QAE@HHNNN@Z) referenced in function _main
1>interestPoints.obj : error LNK2019: unresolved external symbol "public: __thiscall cv::SURF::SURF(double,int,int,bool,bool)" (??0SURF@cv@@QAE@NHH_N0@Z) referenced in function _main
1>D:\visual studio 2010\Exercises\opencv2\MyInterestPoints\Debug\MyInterestPoints.exe : fatal error LNK1120: 2 unresolved externals

所以继续排查原因，知道原来没有把 opencv_nonfree244d.lib 加入lib库中。

添加方法： View -》 Project Manager，



在Property Manager窗口中，右键Debug|Win32，选择Properties，



Linker -》 Input -》 Additional Dependencies -》edit



添加opencv_nonfree244d.lib -》 确定 即可