View source for OpenCV Module in Slicer3

=Steps to Build and Use OpenCV Module=

==My operating system==
The following Linux system is my desktop where this tutorial is based on:<br>
Ubuntu 8.04 - the Hardy Heron - released in April 2008.	<br>
Linux brainlab-desktop 2.6.24-23-generic #1 SMP Mon Jan 26 00:13:11 UTC 2009 i686 GNU/Linux

==Install OpenCV 1.0== 

# Download OpeCV 1.0 at http://sourceforge.net/projects/opencvlibrary/files/. You get file "opencv-1.0.0.tar.gz"
# Move the file to any temporary folder and then unzip it using "tar xvfz opencv-1.0.0.tar.gz". You will get a directory called "opencv-1.0.0"
# cd to opencv-1.0.0 and run these commands:
 ./configure
 make
 sudo make install

<br>The above commands will configure, compile and install opencv 1.0 on your system.

==Test camera==

#My camera is '''Logitech QuickCam Pro for Noteboks'''
#If you don't have a tool called "luvcview," you can get it using this command "sudo apt-get install luvcview"
#Plug in the camera to any usb port on your computer
#Run luvcview

<br>In a few seconds you should see video displayed in luvcview

==Compile Slicer3==

I have created a Slicer3 (in trunk) module named "OpenCV," whose name was suggested by Dr. Noby Hata.
It's basically the videoOpenIGTLink module plus a few bug fixes.
To include this module into your Slicer3 build, open this file:
Slicer3/Modules/CMakeLists.txt

and uncomment "OpenCV" (by default, it's commented for now because it depends on OpenCV library)

==Test the system==
[[Image:opencv_video_from_camera.png|300px|thumb|Video from a camera is displayed in the second window of OpenCV module in Slicer3.]]
#Plug in your camera into any usb port
#Bring Slicer up
#Go to the modules list in Slicer3 interface
#Pick OpenCV module
#Press the button "second window on"

You should see video from the camera in a few seconds.

=Future Work=
# The latest OpenCV library supports svn and CMake. I have built it into the list of Slicer external libraries. When you compile Slicer3, you will automatically get OpenCV library compiled. However, the compilation of OpenCV module in Slicer trunk failed against the library. We need to figure out what caused the failure of that compilation in order to automate the build of OpenCV module.
# More testing of the functionality in OpenCV module.

=Bug Fixes=

* There is a bug in OpenCV related to V4L2 devices:
** Here is the bugtrac with information: [[https://bugs.launchpad.net/ubuntu/+source/linux/+bug/260251]]
** Here is the fix [[http://opencvlibrary.svn.sourceforge.net/viewvc/opencvlibrary/trunk/opencv/src/highgui/cvcap_v4l.cpp?r1=1604&r2=1609]]
*** Apply the changes of revision 1609 to the file # opencv/src/highgui/cvcap_v4l.cpp