Monday, September 26, 2011

OpenCV 2.3.1 on Ubuntu 10.10 or later

*Update: For OpenCV 2.4 on Ubuntu 12.04 see my latest post.

This post will guide you on how to compile and run OpenCV 2.3.1 on Ubuntu 10.10 or later.

First, install all prerequisites:
sudo apt-get install build-essential checkinstall git cmake ffmpeg libfaac-dev libjack-jackd2-dev libmp3lame-dev libopencore-amrnb-dev libopencore-amrwb-dev libsdl1.2-dev libtheora-dev libva-dev libvdpau-dev libvorbis-dev libx11-dev libxfixes-dev libxvidcore-dev texi2html yasm zlib1g-dev libtbb-dev libv4l-dev libopenexr-dev libunicap2-dev libavformat-dev libswscale-dev libdc1394-22-dev libgstreamer0.10-0 libgstreamer0.10-dev gstreamer0.10-tools gstreamer0.10-plugins-base libgstreamer-plugins-base0.10-dev gstreamer0.10-plugins-good gstreamer0.10-plugins-ugly gstreamer0.10-plugins-bad gstreamer0.10-ffmpeg python-numpy
This is not a minimal set of libraries, but it's a collection that will give you most of the functionality. For example, if you are sure that you will never need to use a firewire camera, you can ignore libdc1394-22-dev. But if you actually need to use this feature you will have to recompile OpenCV. Also, if you need CUDA support, follow the instructions in this post before continuing here.

Download OpenCV:
Extract and create a build directory:
tar -xvf OpenCV-2.3.1a.tar.bz2
cd OpenCV-2.3.1/
mkdir build
cd build
Now run cmake:
At this point check the output of cmake to make sure that all the features you are going to need are supported. If not you will have to install the corresponding libraries and run cmake again. Compile:
If everything went well you can go ahead and install:
sudo make install
Finally, add the following lines in your .bashrc:
# OpenCV stuff
To test that everything works, let's run the face detection demo. Go to the bin directory:
cd bin
And run:
./facedetect --cascade="../../data/haarcascades/haarcascade_frontalface_alt.xml" --nested-cascade="../../data/haarcascades/haarcascade_eye.xml" --scale=1.3 ../../samples/c/lena.jpg
You should see something like this:

How to install CUDA 4.0 on Ubuntu 10.10 or later

First, you need to install the NVIDIA development drivers. Download the current version (270.41.19) here.
To install the dev drivers, reboot and go into recovery mode. Select the "Drop to root shell prompt" option. Now type:
sudo telinit 3
Login again using your username, then cd to the directory where you downloaded the drivers (e.g. ~/Downloads):
cd ~/Downloads
chmod u+x
sudo ./
Follow the instructions on the screen. Make sure you write to your xorg.conf file. When done reboot:
sudo reboot
Download the CUDA Toolkit from this page (Linux -> CUDA Toolkit for Ubuntu Linux 10.10).
cd ~/Downloads
chmod u+x
sudo ./
Finally, download the GPU Computing SDK from the above website.
cd ~/Downloads
chmod u+x gpucomputingsdk_4.0.17_linux
Add the these lines at the end of your ~/.profile (if your OS is 32-bit, remove the lib64 entry):
#CUDA stuff
export PATH=/usr/local/cuda/bin:$PATH
export LD_LIBRARY_PATH=/usr/local/cuda/lib:/usr/local/cuda/lib64:$LD_LIBRARY_PATH
Now you just need to compile the samples. Assuming you installed the SDK in your home directory:
cd ~/NVIDIA_GPU_Computing_SDK
You can now run one of the demos, e.g. the particle demo
and you should see something like this: