c++ - OpenCV - DLL missing, but it's not?

Question

I am trying just a basic program with OpenCV with the following code:

#include "cv.h"
#include "highgui.h"

int main()
{
    IplImage* newImg;
    newImg = cvLoadImage("~/apple.bmp", 1);
    cvNamedWindow("Window", 1);
    cvShowImage("Window", newImg);
    cvWaitKey(0);
    cvDestroyWindow("Window");
    cvReleaseImage(&newImg);
    return 0;
}

When I run this, I get

The program can't start because libcxcore200.dll is missing from your computer. Try reinstalling the program to fix this problem.

However, I can see this DLL. It exists. I have added the following to the input dependencies for my linker

C:OpenCV2.0liblibcv200.dll.a C:OpenCV2.0liblibcvaux200.dll.a C:OpenCV2.0liblibcxcore200.dll.a C:OpenCV2.0liblibhighgui200.dll.a

What gives? I'm using visual studio 2008.

When I link the .dll files instead of .dll.a files, I get

fatal error LNK1107:invalid or corrupt file: cannot read at 0x3F8 libcv200.dll

Answer 1

I followed instructions on http://opencv.willowgarage.com/wiki/VisualC%2B%2B_VS2010 but was still stuck on exactly the same problem, so here's how I resolved it.

1. Fetched MSVC 2010 express edition.

2. Fetched Win 32 OpenCV 2.2 binaries and installed in default location.

3. Created new project.

4. Project setup

   Project -> OpenCV_Helloworld Properties...Configuration Properties -> VC++ Directories

   Include Directories... add: C:OpenCV2.2include;

   Library Directories... add: C:OpenCV2.2lib;C:OpenCV2.2in;

   Source Directories... add:

   C:OpenCV2.2modulescalib3dsrc;C:OpenCV2.2modulescontribsrc;C:OpenCV2.2modulescoresrc;C:OpenCV2.2modulesfeatures2dsrc;C:OpenCV2.2modulesflannsrc;C:OpenCV2.2modulesgpusrc;C:OpenCV2.2modulesgpusrc;C:OpenCV2.2moduleshighguisrc;C:OpenCV2.2modulesimgprocsrc;C:OpenCV2.2moduleslegacysrc;C:OpenCV2.2modulesmlsrc;C:OpenCV2.2modulesobjdetectsrc;C:OpenCV2.2modulesvideosrc;
   

   Linker -> Input -> Additional Dependencies...

   For Debug Builds... add:

   opencv_calib3d220d.lib;opencv_contrib220d.lib;opencv_core220d.lib;opencv_features2d220d.lib;opencv_ffmpeg220d.lib;opencv_flann220d.lib;opencv_gpu220d.lib;opencv_highgui220d.lib;opencv_imgproc220d.lib;opencv_legacy220d.lib;opencv_ml220d.lib;opencv_objdetect220d.lib;opencv_video220d.lib;
   

At this point I thought I was done, but ran into the problem you described when running the exe in debug mode. The final step is obvious once you see it, select:

Linker -> General ... Set 'Use Library Dependency Inputs' to 'Yes'

Hope this helps.