Eric Beets' wouaib

What is OpenCV

OpenCV means Intel® Open Source Computer Vision Library. It is a collection of C functions and few C++ classes that implement some popular algorithms of Image Processing and Computer Vision.

The key features

OpenCV is cross-platform middle-to-high level API that consists of a few hundreds (>300) C functions. It does not rely on external numerical libraries, though it can make use of some of them (see below) at runtime, if they are available.

OpenCV is free for both non-commercial and commercial use (see the license for details).

OpenCV provides transparent for user interface to Intel® Integrated Performance Primitives (IPP) (only ippcv for now). That is, it loads automatically IPP libraries optimized for specific processor at runtime, if they are available. More information about IPP can be retrieved at http://www.intel.com/software/products/ipp/ippvm20/index.htm

There are interfaces to OpenCV for some other languages/environments (more to come):

EiC - ANSI C interpreter written by Ed Breen. AFAIK, it is now abandoned. Hawk and CvEnv are the interactive environments (written in MFC and TCL,respectively) that embedd EiC interpteter.
Ch - ANSI C/C++ interpreter with some scripting capabilities, created and supported by SoftIntegration® company (http://www.softintegration.com) W rappers for Ch are located at opencv/interfaces/ch.
MATLAB® - great environment for numerical and symbolic computing by Mathworks. MATLAB® interface for some of OpenCV functions can be found at opencv/interfaces/matlab/toolbox

Firstly the Yahoo group list is very useful for all questions, the last innovation, and all delcared users' contacts.

SourceForge download
Windows installation
Linux installation
Installation test
Documentation
Windows examples
Linux examples

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SourceForge download

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Above all, you have to download this library. SourceForge web site provides the last update (personally, I'm using the beta3.1, it's the last at the present time).
Downloaded once, this library has to be installed.

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Windows Installation

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Normally, for the windows installation, there isn't any troubles, so 'ok', 'next', 'next', 'ok', etc...
chargement..

In the 'start' menu, now, we can see : chargement..

We can also see in the OpenCV installation directory (in my example : c:\Program Files\OpenCV) chargement..

Now, OpenCV is installed. But you have to compile it before use it. To compile the libraries (cv.lib, cv.dll, highgui.lib, highgui.dll, cvaux.lib, cvaux.dll, etc..), I'm going to use Visual C++. Opening the file OpenCV.dsp (which is in _dsw or start -> Programs -> OpenCV -> OpenCV Workspace), you can find : chargement..

Those are all the OpenCV project, start compiling :

CV Files
HighGUI files
cvaux files

Now, to be able to compile a code source with visual using OpenCV, you have to copy dll files into your work directory (it depends of your needs), as usual :

cv.dll
highgui.dll
cvaux.dll

Those files are using for the execution.

To compile your program with Visual C++, you have to add OpenCV headers directories, such as :

in Tools -> Options In 'Include files'
- c:\PROGRAM FILES\OPENCV\CV\INCLUDE for cv.h
- c:\PROGRAM FILES\OPENCV\OTHERLIBS\HIGHGUI for highgui.h
To avoid those errors : fatal error C1083: Cannot open include file: 'cv.h': No such file or directory

In 'Library files'
- c:\PROGRAM FILES\OPENCV\LIB for cv.lib, highgui.lib, cvaux.lib, etc..
To avoid those errors : LINK : fatal error LNK1104: cannot open file "cv.lib"
To link your program with Visual C++,you have to add OpenCV statics libs, such as:

in Project->Settings, Link in 'Object/library modules'
- cv.lib, highgui.lib (optional cvaux.lib)
To avoid this kind of errors : File.obj : error LNK2001: unresolved external symbol _cvFlip... _cvRectangle... _cvCircle... _cvFindCornerSubPix... _cvCopy for cv.lib
or File.obj : error LNK2001: unresolved external symbol "public: virtual __thiscall CvvImage::~CvvImage(void)" (??1CvvImage@@UAE@XZ) for highgui.lib

Now you're ready to play with OpenCV

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Linux Installation

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Debian Installation

Pakages list :


         apt-cache search opencv

libcvaux-dev	- development files for libcvaux
libcvaux0.9-5	- computer vision extension library
libcvcam-dev	- development files for libcvcam
libcvcam0.9-5	- computer vision camera support library
libhighgui-dev	- development files for libhighgui
libhighgui0.9-5	- computer vision GUI library
libopencv-dev	- development files for libopencv
libopencv-doc	- OpenCV documentation and examples
libopencv0.9-5	- computer vision library

Installation (thx zam):


         apt-get install libcvaux-dev libcvaux0.9-5 libcvcam-dev libcvcam0.9-5 libhighgui-dev libhighgui0.9-5 libopencv-dev libopencv-doc libopencv0.9-5

TAR installation

Archive extraction

gunzip opencv-0.9.5.tar.gz

tar -xvf opencv-0.9.5.tar

tar -xzvf opencv-0.9.5.tar.gz

Pre-necessary :

motif (LessTif or openMotif) with files developpement
libpng, libjpeg, libtiff with files developpement
libavcodec de ffmpeg with the headers
fltk 1.1.x with files developpement
TCL/TK 8.3.x et BWidgets with files developpement

Library installation :

./configure

make

make install # as root

ldconfig # as root

NB : Personaly, I had troubles with the configure file : the X11 library directory wasn't the good ... so, to check before look for during two weeks...

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Installation test

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Compilation test with this small example :


         
         /*

          * foo.c

          */

         
         #include <cv.h>

         #include <highgui.h>

         int main(int argc,char *argv[])

         {

           IplImage *image;

           int x,y;

           image = cvCreateImage(cvSize(300,300),8,1);

           cvSetZero(image);

           for(y=0 ; y < image->height ; y++)

           {

             for(x=0; x < image->width ; x++)

             {

               (image->imageData+image->widthStep*y)[x] = (x*y)%256

             }

           }

           cvNamedWindow("Image",1)

           cvShowImage("Image",image);

           cvWaitKey(0);

           return 0;

         }

Compilation line (under debian) :

gcc opencv-config --cflags --libs highgui foo.c -o foo

Resultat of this source code :

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Documentation

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Actually, OpenCV help are declared. There are three, actually, more two and half than three :

Local help ($OPENCVROOT\docs\index.htm)
Le Forum sur Yahoo(you have to be registred)
On line (search on google google for instance)
INSTALL

On line, help aren't a lot.

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Windows examples

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Under Windows, it exists few examples :

StereoDemo	Stereovision manipulation example using the camera intrinseqs parameters
LKDemo	Corner Tracker example, very powerfully using optic flow
VMDemo	Morphing example using epipolar lines
HMMDemo	Face recognition example empirical method learning

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Linux examples

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The first example that can check the good installation with the following script opencv-config :

Usage: opencv-config [OPTIONS]

Options:

[--prefix]

[--cflags]

[--cxxflags]

[--libs [opencv] [highgui] [cvcam] [cvaux]]

[--version]

opencv-config --prefix

/usr

opencv-config --cflags

-I/usr/include/opencv

opencv-config --cxxflags

-I/usr/include/opencv

opencv-config --libs opencv highgui cvcam cvaux

-lopencv -lopencv -lhighgui -lcvcam -lcvaux

opencv-config --version

0.9.5

Libs

What is OpenCV

The key features

Windows Installation

Linux Installation

Debian Installation

TAR installation

Installation test

Documentation

Windows examples

Linux examples