Problem in load library when using opencv and matlab

http://blog.cordiner.net/2010/02/15/opencv-viola-jones-object-detection-in-matlab/ describes how to use OpenCv with matlab. I tried to execute the following command given at the end of the page :

 opencvPath = 'C:\Program Files (x86)\OpenCV1.1';
    includePath = fullfile(opencvPath, 'cxcore\include');

loadlibrary(...
  fullfile(opencvPath, 'bin\cxcore110.dll'), ...
  fullfile(opencvPath, 'cxcore\include\cxcore.h'), ...
    'mfilename', 'proto_cxcore');

loadlibrary(...
  fullfile(opencvPath, 'bin\cv110.dll'), ...
  fullfile(opencvPath, 'cv\include\cv.h'), ...
    'alias', 'cv110', 'includepath', includePath);
loadlibrary(...
  fullfile(opencvPath, 'bin\highgui110.dll'), ...
  fullfile(opencvPath, 'otherlibs\highgui\highgui.h'), ...
    'alias', 'highgui110', 'includepath', includePath);
classifierFilename = 'C:/Program Files (x86)/OpenCV1.1/data/haarcascades/haarcascade_frontalface_alt.xml';
cvCascade = calllib('cv110', 'cvLoadHaarClassifierCascade', classifierFilename, ...
  libstruct('CvSize',struct('width',int16(100),'height',int16(100))));

However,it returns an error ??? Error using ==> loadlibrary at 279 Microsoft Visual C++ 2005 or 2008 is required to use this feature.

Error in ==> opencv_test_prototype at 4
loadlibrary(...

I have Visual Studio 2010 Express as well as 2008 installed and have worked with MEX files before. I dont know how to proceed. Kindly help

Answer 1

[Kaustubha Govind]

See if this previous discussion helps: http://www.mathworks.it/matlabcentral/answers/27971-loadlibrary-error

[chitra]

I am running the program on R2011a but the answer in the link is applicable for older versions of matlab. Could u be more clear please.Thanx

[Kaustubha Govind]

Try running the command "mex -setup" in MATLAB and allow the utility to automatically locate installed compilers. Is it able yo find one of your installed Visual Studio compilers? If yes, select them, and try loadlibrary again.

[chitra]

Hi Kaustubha,I did what you said but its the same thing,same load library error.I have 2010 also and I performed mex -setup and it showed Please choose your compiler for building external interface (MEX) files:

Would you like mex to locate installed compilers [y]/n? y

Select a compiler:

[1] Microsoft Visual C++ 2010 Express in c:\Program Files (x86)\Microsoft Visual Studio 10.0

[2] Microsoft Visual C++ 2008 SP1 in C:\Program Files (x86)\Microsoft Visual Studio 9.0

[0] None

Compiler: 2,

Now on selecting 2 it shows Error: Could not find the 64-bit compiler. This may indicate that the

"X64 Compilers and Tools" or the Microsoft Windows Software

Development Kit (SDK) is not installed. To build 64-bit MEX-files

Microsoft Visual C++ 2008 requires that these two packages are

installed properly.

*****************************************************************************

Trying to update options file: C:\Users\Sumona\AppData\Roaming\MathWorks\MATLAB\R2010b\mexopts.bat

From template: C:\PROGRA~1\MATLAB\R2010b\bin\win64\mexopts\msvc90opts.bat

Done . . .

But load library error repeats and it mentions that I must have 2008. Now I selected second time VS2010 but the error remains. So, do I have to install those missing Microsoft Windows Software

Development Kit (SDK) although my system has SDK7.1. Please explain what to do.Thanx

[Walter Roberson]

VS2008 requires SDK 6.1 I believe.

[Kaustubha Govind]

Chitra: You do see the message "Error: Could not find the 64-bit compiler. This may indicate that the

"X64 Compilers and Tools" or the Microsoft Windows Software

Development Kit (SDK) is not installed. To build 64-bit MEX-files

Microsoft Visual C++ 2008 requires that these two packages are

installed properly. " - which means that you did not install the "X64 Compilers and Tools" package when you installed Visual Studio - these are needed to compiler 64-bit binaries (by default, Visual Studio can only compiler 32-bit binaries). See if re-installing this Visual Studio package fixes the loadlibrary issue.

[Kaustubha Govind]

And like Walter recommend, you also need the appropriate SDK.

[chitra]

Hi Kaustubha and Walter: I followed all the steps described in link http://www.mathworks.com/support/solutions/en/data/1-6IJJ3L/?solution=1-6IJJ3L . Now in mex setup there is no error(the prev err Could not find 64 bit compiler etc vanished). However,the load library error remains! What else is left to do now?

[Kaustubha Govind]

Chitra - you mentioned in your previous comment that you are using R2011a, but from the output of your "mex -setup" it shows that you are using R2010b, which is older than R2011a. The previous discussion I pointed to in my original answer is applicable to you.

Answer 2

[Zaigham Bajwa]

Failed to find OpenCV libraries in C:\opencv\build\x64\mingw\lib

Dont know what the error is ?

[Walter Roberson]

Where did you install OpenCV ?

[Zaigham Bajwa]

C:\opencv

This is the location