Compile opencv3.1 with mingw - c++

Question

I want to compile the following code with mingw-w64.
#include <iostream>
#include <opencv2/core.hpp>
#include <opencv2/highgui.hpp>
#include <opencv2/opencv.hpp>
using namespace cv;
using namespace std;
int main(int argc, char** argv)
{
Mat im = imread("lena.jpg", 1);
if (im.empty())
{
cout << "Cannot open image!" << endl;
return -1;
}
imshow("image", im);
waitKey(0);
return 0;
}
after following Getting started with OpenCV 2.4 and MinGW on Windows 7
I compile the code with g++ -I D:\opencv\build\include -L D:\opencv\build\x64\vc14\lib -lopencv_world310 .\loadimg.cpp
but it returns undefined reference
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text+0x40): undefined reference to `cv::imread(cv::String const&, int)'
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text+0xb7): undefined reference to `cv::imshow(cv::String const&, cv::_InputArray const&)'
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text+0xd9): undefined reference to `cv::waitKey(int)'
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text$_ZN2cv6StringC1EPKc[_ZN2cv6StringC1EPKc]+0x4a): undefined reference to `cv::String::allocate(unsigned long long)'
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text$_ZN2cv6StringD1Ev[_ZN2cv6StringD1Ev]+0x11): undefined reference to `cv::String::deallocate()'
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text$_ZN2cv3MatD1Ev[_ZN2cv3MatD1Ev]+0x36): undefined reference to `cv::fastFree(void*)'
C:\Users\1409021\AppData\Local\Temp\cc8ZRPJP.o:loadimg.cpp:(.text$_ZN2cv3Mat7releaseEv[_ZN2cv3Mat7releaseEv]+0x48): undefined reference to `cv::Mat::deallocate()'
the library is opencv3.1, and there is only one library opencv_world310
Any advise?
Thank you.

Answer 1

g++ -I D:\opencv\build\include -L D:\opencv\build\x64\vc14\lib -lopencv_world310 .\loadimg.cpp
is wrong.
g++ -I D:\opencv\build\include -L D:\opencv\build\x64\vc14\lib .\loadimg.cpp -lopencv_world310
is right. Explained here