unresolved external symbol error when importing libraries for OpenCV2.3 in Visual Studios 2010 Express C++

first time posting a question here to stackoverflow. Sorry if I butcher the formatting!

I am attempting to follow a basic tutorial on openCV, namely this one: http://aishack.in/tutorials/tracking-colored-objects-in-opencv/

I have looked at various tutorial online on how to install openCV, including:

Setup OpenCV-2.3 for Visual Studio 2010 and opencv.willowgarage.com/wiki/VisualC%2B%2B

without much luck.

The current version I have running right now is OpenCV 2.3.0. I am currently running on Windows 7 with Microsoft Visual C++ Express 2010.

Whenever I try to build and run my code, I get the following errors:

1>------ Build started: Project: Camera, Configuration: Debug Win32 ------
1>camera.obj : error LNK2019: unresolved external symbol _cvReleaseImage referenced in function "struct _IplImage * __cdecl GetThresholdedImage(struct _IplImage *)" (?GetThresholdedImage@@YAPAU_IplImage@@PAU1@@Z)
1>camera.obj : error LNK2019: unresolved external symbol _cvInRangeS referenced in function "struct _IplImage * __cdecl GetThresholdedImage(struct _IplImage *)" (?GetThresholdedImage@@YAPAU_IplImage@@PAU1@@Z)
1>camera.obj : error LNK2019: unresolved external symbol _cvCvtColor referenced in function "struct _IplImage * __cdecl GetThresholdedImage(struct _IplImage *)" (?GetThresholdedImage@@YAPAU_IplImage@@PAU1@@Z)
1>camera.obj : error LNK2019: unresolved external symbol _cvCreateImage referenced in function "struct _IplImage * __cdecl GetThresholdedImage(struct _IplImage *)" (?GetThresholdedImage@@YAPAU_IplImage@@PAU1@@Z)
1>camera.obj : error LNK2019: unresolved external symbol _cvGetSize referenced in function "struct _IplImage * __cdecl GetThresholdedImage(struct _IplImage *)" (?GetThresholdedImage@@YAPAU_IplImage@@PAU1@@Z)
1>camera.obj : error LNK2019: unresolved external symbol _cvReleaseCapture referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvWaitKey referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvShowImage referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvAdd referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvLine referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvGetCentralMoment referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvGetSpatialMoment referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvMoments referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvQueryFrame referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvNamedWindow referenced in function _main
1>camera.obj : error LNK2019: unresolved external symbol _cvCreateCameraCapture referenced in function _main
1>C:\Users\Kevin\Documents\Visual Studio 2010\Projects\Camera\Debug\Camera.exe : fatal error LNK1120: 16 unresolved externals
========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

My code is as follows:

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

IplImage* GetThresholdedImage(IplImage* img)
{
IplImage* imgHSV = cvCreateImage(cvGetSize(img), 8, 3);
cvCvtColor(img, imgHSV, CV_BGR2HSV);
IplImage* imgThreshed = cvCreateImage(cvGetSize(img), 8, 1);
cvInRangeS(imgHSV, cvScalar(20, 100, 100), cvScalar(30, 255, 255), imgThreshed);
cvReleaseImage(&imgHSV);
return imgThreshed;
}

int main()
{
CvCapture* capture = 0;
capture = cvCaptureFromCAM(1);
  if(!capture)
{
    printf("Could not initialize capturing...\n");
    getchar();
    return -1;
}

cvNamedWindow("video");
cvNamedWindow("thresh");
IplImage* imgScribble = NULL;

while(1)
{
    IplImage* frame = 0;
    frame = cvQueryFrame(capture);

    if(!frame)
        break;
    //cvErode(frame, frame, 0, 2); // ADD this line
    //initalize the scribble frame if has not already been done yet
    if(imgScribble == NULL)
    {
        imgScribble = cvCreateImage(cvGetSize(frame), 8, 3);
    }
    IplImage* imgYellowThresh = GetThresholdedImage(frame);

    CvMoments *moments = (CvMoments*)malloc(sizeof(CvMoments));
    cvMoments(imgYellowThresh, moments, 1);

    // The actual moment values
    double moment10 = cvGetSpatialMoment(moments, 1, 0);
    double moment01 = cvGetSpatialMoment(moments, 0, 1);
    double area = cvGetCentralMoment(moments, 0, 0);

    // Holding the last and current ball positions
    static int posX = 0;
    static int posY = 0;

    int lastX = posX;
    int lastY = posY;

    posX = moment10/area;
    posY = moment01/area;

    printf("position (%d,%d)\n", posX, posY);

    // We want to draw a line only if its a valid position
    if(lastX>0 && lastY>0 && posX>0 && posY>0)
    {
        // Draw a yellow line from the previous point to the current point
        cvLine(imgScribble, cvPoint(posX, posY), cvPoint(lastX, lastY), cvScalar(0,255,255), 5);
    }


    cvAdd(frame, imgScribble, frame);
    cvShowImage("thresh", imgYellowThresh);
    cvShowImage("video", frame);

    int c = cvWaitKey(5);
        if((char)c==27 )
        break;

    // Release the thresholded image+moments... we need no memory leaks.. please
    cvReleaseImage(&imgYellowThresh);

    delete moments;
}
// We're done using the camera. Other applications can now use it
 cvReleaseCapture(&capture);
cvReleaseCapture(&capture);
return 0;

}

I have installed Open CV to C:\OpenCV2.3

I have added additional dependencies, additional directories, ect. For the preferences for my project, they are as follows:

Additional Dependencies:

enter code here
opencv_core230.lib
opencv_highgui230.lib
opencv_legacy230.lib
opencv_video230.lib
opencv_ml230.lib
opencv_core230d.lib
opencv_highgui230d.lib
opencv_legacy230d.lib
opencv_video230d.lib
opencv_ml230d.lib
opencv_calib3d230d.lib

Aditional Library Directories: C:\OpenCV2.3\build\x64\vc10\lib;C:\OpenCV2.3\build\x64\vc10\bin;C:\OpenCV2.3\build\x64\vc10\staticlib;%(AdditionalLibraryDirectories)

Additional Include Directories:

C:\OpenCV2.3\build\include\opencv;C:\OpenCV2.3\build\include\opencv2;C:\OpenCV2.3\build\include

I also included a path to the DLL's on my path variable for windows:

;C:\OpenCV2.3\build\x64\vc10\bin;C:\OpenCV2.3\build\bin;

I've looked at other forums, other stack overflow questions, ect without much help. I have been trying to get this to work for the better part of a weekend. Any help would be much appreciated!

If you DID explicitly set up linking with all the necessary libraries, but linking errors still show, you might be mixing up 64/32 bit libraries and application.

I.e. make sure that all library includes point to 32 bit version of libraries if you are building 32 bit application.

I had a similar problem while I was trying to compile cvblob library (http://code.google.com/p/cvblob/) on Windows 7 32bit with Visual Studio 2010.

If everything else is done properly try my guess written below. If not start with these tutorials:

Installing OpenCV: http://docs.opencv.org/trunk/doc/tutorials/introduction/windows_install/windows_install.html#cpptutwindowsmakeown
Configuring your projects to build and work with opencv: http://docs.opencv.org/trunk/doc/tutorials/introduction/windows_visual_studio_Opencv/windows_visual_studio_Opencv.html#windows-visual-studio-how-to.

These silimar linker errors disappeared after changing some project properties:
- In VS 2010 open Your solution
- Open solution explorer (View->Solution Explorer)
- Find a project that generated these linker errors. (In my example it was a project called "cvblob" inside solution called "cvBlob" generated by cmake.)
- right click on that project
- From the context menu select properties
- On the left select Configuration properties -> General and find a field called "Target extension"
- In Project Details find your project settings for "Configuration Type"
- analyse them. In my particular problem of compiling cvblob I had to set Target extension to .lib and Configuration type to Static library. This is also a solution for guys trying to compile cvblob library in Visual Studio 2010. Do the same for Debug and Release version if needed.

Errors I got were:

Error 24 error LNK2019: unresolved external symbol _cvSetImageROI referenced in function _cvSetImageROItoBlob C:\cvblob\build\lib\cvblob.obj cvblob

Error 25 error LNK2019: unresolved external symbol _cvSaveImage referenced in function _cvSaveImageBlob C:\cvblob\build\lib\cvblob.obj cvblob

Error 26 error LNK2019: unresolved external symbol _cvGetImageROI referenced in function _cvSaveImageBlob C:\cvblob\build\lib\cvblob.obj cvblob

Error 27 error LNK2001: unresolved external symbol _cvError C:\cvblob\build\lib\cvcolor.obj cvblob

Error 28 error LNK2019: unresolved external symbol _cvError referenced in function _cvRenderBlob C:\cvblob\build\lib\cvblob.obj cvblob

Error 29 error LNK2001: unresolved external symbol _cvError C:\cvblob\build\lib\cvlabel.obj cvblob

Error 30 error LNK2001: unresolved external symbol _cvError C:\cvblob\build\lib\cvcontour.obj cvblob

Error 31 error LNK2001: unresolved external symbol _cvError C:\cvblob\build\lib\cvtrack.obj cvblob

Error 32 error LNK2019: unresolved external symbol _cvLine referenced in function _cvRenderBlob C:\cvblob\build\lib\cvblob.obj cvblob

Error 33 error LNK2001: unresolved external symbol _cvLine C:\cvblob\build\lib\cvcontour.obj cvblob

Error 34 error LNK2019: unresolved external symbol _cvRectangle referenced in function _cvRenderBlob C:\cvblob\build\lib\cvblob.obj cvblob

Error 35 error LNK2001: unresolved external symbol _cvRectangle C:\cvblob\build\lib\cvtrack.obj cvblob

Error 36 error LNK2019: unresolved external symbol _cvSetZero referenced in function _cvLabel C:\cvblob\build\lib\cvlabel.obj cvblob

Error 37 error LNK2019: unresolved external symbol _cvPutText referenced in function _cvRenderTracks C:\cvblob\build\lib\cvtrack.obj cvblob

Error 38 error LNK2019: unresolved external symbol _cvInitFont referenced in function _cvRenderTracks C:\cvblob\build\lib\cvtrack.obj cvblob

Error 39 error LNK1120: 9 unresolved externals C:\cvblob\build\lib\libs\Release\cvblob.dll cvblob

I hope it will help someone compiling cvblob library in visual studio 2010.

I had similar problem in vs10 and i have forgot to add the cv210d.lib. Adding that to project properties->configuration properties-> Linker->Input->Aditional Dependencies helped me in solving this issue. I found from the question that opencv_cv230.lib was not included in additional dependencies adding that will help solving the issue.

I Had The Same Problem, in vs10

i've missed the "opencv_core246d.lib" to add. adding it to Linker->Input->Aditional Dependencies fixed error.

Cloud Guy

This might help with the newer version.
For version 2.4.8, adding opencv_imgproc248.lib resolves the following linking error:

error LNK2019: unresolved external symbol _cvRemap referenced in function _main
error LNK2019: unresolved external symbol _cvInitUndistortMap referenced in function _main
error LNK2019: unresolved external symbol _cvFindCornerSubPix referenced in function _main
error LNK2019: unresolved external symbol _cvCvtColor referenced in function _main

for me, this error got resolved by adding two lib name explicitly under input (configuration properties-->linker-->input-->additional dependencies).

when you install opencv , based on version it will have a number appended to it. For example I have opencv2.4.13 and it has 2413 appended to all its libraries, opencv_highgui2413.lib (opencv_highgui2413d.lib for debug build ).

Now,check which libraries have the functions that were shown in errors. highgui has cvshowimage function --> you can get this by searing it online. http://docs.opencv.org/2.4/modules/highgui/doc/user_interface.html

Then add that lib to input and build your solution.

来源：https://stackoverflow.com/questions/10474218/unresolved-external-symbol-error-when-importing-libraries-for-opencv2-3-in-visua

标签

visual-studio-2010

OpenCV

lnk2019