Undefined reference in opencv with devc++ [duplicate] - c++

Question

This question already has answers here:
What is an undefined reference/unresolved external symbol error and how do I fix it?
(39 answers)
Closed 6 years ago.
I was trying to install opencv with devc++ on my windows system. I installed opencv and then added a new compiler in devc++.
I added the following command in calling the new compiler section
-L"C:\OpenCV\lib" -lcxcore210 -lcv210 -lcvaux210 -lhighgui210 -lml210
I added the follwing command for linker command line
-lcxcore210 -lcv210 -lcvaux210 -lhighgui210 -lml210
I added the corresponding opencv binaries,libraries and includes too and added opencv/bin to environment variables.
However when i try to run follwing opencv code,
#include <iostream>
#include <conio.h>
using namespace std;
#include "cv.h"
#include "highgui.h"
using namespace cv;
int main()
{
cv::Mat img;
getch();
}
It gives the following error.
[Linker error]
C:\Users\user\AppData\Local\Temp\ccGQvgqG.o:filename.cpp:(.text$_ZN2cv3Mat7releaseEv[cv::Mat::release()]+0x3f):
undefined reference to `cv::fastFree(void*)'

Answer 1

Please, do not use OpenCV 2.1.0.
Use OpenCV 2.4.13 or 3+.
As you can read in the documentation:
Prebuilt libraries [...] only works if you are coding with the latest Microsoft Visual Studio IDE.
If you want to use other compiler than Visual C++, you must build OpenCV libraries yourself. A good start is this tutorial. Take care, because they are "long-obsolete and contain inaccurate information".