OpenCV error: "LINK : fatal error LNK1104: cannot open file 'opencv_core231d.lib' "

Question

I'm trying to compile a simple code in visual studio + opencv, but got this error.

Code:

#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace cv;

int main ( int argc, char **argv )

{
    Mat im_gray;
    Mat img_bw;
    Mat img_final;

    Mat im_rgb  = imread("001.jpg");
    cvtColor(im_rgb,im_gray,CV_RGB2GRAY);

    adaptiveThreshold(im_gray, img_bw, 255, ADAPTIVE_THRESH_MEAN_C, THRESH_BINARY_INV, 105, 1); 

    imwrite("001-bw2.jpg", img_final);
    return 0;
}  

Output:

1>------ Build started: Project: pibiti, Configuration: Debug Win32 ------
1>LINK : fatal error LNK1104: cannot open file 'opencv_core231d.lib'
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

The Linker >> Input:

opencv_core231d.lib
opencv_highgui231d.lib
opencv_video231d.lib
opencv_ml231d.lib
opencv_legacy231d.lib
opencv_imgproc231d.lib
tbb_debug.lib
tbb_preview_debug.lib
tbbmalloc_debug.lib
tbbmalloc_proxy_debug.lib
tbbproxy_debug.lib

How can I fix this? the file 'opencv_core231d.lib' is already there, why this error?

Answer 1

Add the path of the library files to the library path.

Right click the project and go to Properties->Linker->Additional Library directories. Add the path to this list.

Answer 2

Adding to this list of solutions, mine was simply to change the project to 64 bit.

Answer 3

I had the same issue. Despite ensuring that the path to the libraries was correct, I was getting a "Cannot open file" error. The issue was I had named the dlls wrong in additional assembly references in Linker Properties. I had given them as above(with "231" at end). But the names of the actual Dlls were ending with "249". Changing that solved my issue. Might be helpful to others :-)

After this, project will get built successfully. But you can expect a run time error that opencv_core249d.lib is missing in your computer, you need to re-install it. That is becuase even though the path has been added to environment variables, windows has to be restarted to have it in effect. This will solve it.