1>------ Build started: Project: opencv demo, Configuration: Debug Win32 ------ 1>Build started 6/25/2015 3:05:26 PM. 1>InitializeBuildStatus: 1> Touching "Debug\opencv demo.unsuccessfulbuild". 1>ClCompile: 1> All outputs are up-to-date. 1>ManifestResourceCompile: 1> All outputs are up-to-date. 1>main.obj : error LNK2019: unresolved external symbol "int __cdecl cv::waitKey(int)" (?waitKey@cv@@YAHH@Z) referenced in function _main 1>main.obj : error LNK2019: unresolved external symbol "void __cdecl cv::imshow(class cv::String const &,class cv::_InputArray const &)" (?imshow@cv@@YAXABVString@1@ABV_InputArray@1@@Z) referenced in function _main 1>main.obj : error LNK2019: unresolved external symbol "class cv::Mat __cdecl cv::imread(class cv::String const &,int)" (?imread@cv@@YA?AVMat@1@ABVString@1@H@Z) referenced in function _main 1>main.obj : error LNK2019: unresolved external symbol "private: char * __thiscall cv::String::allocate(unsigned int)" (?allocate@String@cv@@AAEPADI@Z) referenced in function "public: __thiscall cv::String::String(char const *)" (??0String@cv@@QAE@PBD@Z) 1>main.obj : error LNK2019: unresolved external symbol "private: void __thiscall cv::String::deallocate(void)" (?deallocate@String@cv@@AAEXXZ) referenced in function "public: __thiscall cv::String::~String(void)" (??1String@cv@@QAE@XZ) 1>main.obj : error LNK2019: unresolved external symbol "void __cdecl cv::fastFree(void *)" (?fastFree@cv@@YAXPAX@Z) referenced in function "public: __thiscall cv::Mat::~Mat(void)" (??1Mat@cv@@QAE@XZ) 1>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall cv::Mat::deallocate(void)" (?deallocate@Mat@cv@@QAEXXZ) referenced in function "public: void __thiscall cv::Mat::release(void)" (?release@Mat@cv@@QAEXXZ) 1>C:\Users\phadu\documents\visual studio 2010\Projects\opencv demo\Debug\opencv demo.exe : fatal error LNK1120: 7 unresolved externals 1> 1>Build FAILED. 1> 1>Time Elapsed 00:00:02.32 ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========