How to install openCV 2.4.13 for Python 2.7 on Ubuntu 16.04?

According to this source, from Ubuntu 16.04, you can now just do this to install OpenCV for Python2.7:

pip install opencv-python

or for python3:

pip3 install opencv-python

For more information, see here.

I tested this on my machine and it works, great stuff this :).

This is much easier than all other methods I have come across thus far.

There's a script I had made a while back, for installing the latest version of OpenCV (4.2 as of the last update to this answer) Here's the link to it

https://github.com/rsnk96/Ubuntu-Setup-Scripts/blob/master/Build-OpenCV.sh

NOTE: For Ubuntu 16.10+, there are some minor dependency changes you will have to make. Have a look at the comments for the same.

Since you do not want to install opencv contrib, and you specifically want opencv 2.4.13, I have modified the script below. I would suggest you go through the script and understand what is happening before you execute it

sudo apt-get update
sudo apt-get upgrade -y

sudo apt-get install build-essential -y
sudo apt-get install cmake git libgtk2.0-dev pkg-config libavcodec-dev libavformat-dev libswscale-dev -y

sudo apt-get install python3-numpy python3-pip python3-scipy python3-matplotlib python-dev python-matplotlib python-numpy python-scipy -y

sudo apt-get install python-pip python-tk libqt4-dev libqt4-opengl-dev  libeigen3-dev yasm libfaac-dev libopencore-amrnb-dev libopencore-amrwb-dev libtheora-dev libvorbis-dev libxvidcore-dev libx264-dev sphinx-common texlive-latex-extra libv4l-dev libdc1394-22-dev libavcodec-dev libavformat-dev libswscale-dev default-jdk ant -y


echo "GUI and openGL extensions"
sudo apt-get install qt4-default libqt4-opengl-dev libvtk5-qt4-dev libgtk2.0-dev libgtkglext1 libgtkglext1-dev -y

echo "image manipulation libraries"
sudo apt-get install libpng3 pngtools libpng12-dev libpng12-0 libpng++-dev -y
sudo apt-get install libjpeg-dev libjpeg9 libjpeg9-dbg libjpeg-progs libtiff5-dev libtiff5 libtiffxx5 libtiff-tools libjasper-dev libjasper1  libjasper-runtime zlib1g zlib1g-dbg zlib1g-dev -y

echo "video manipulation libraries"
sudo apt-get install libavformat-dev libavutil-ffmpeg54 libavutil-dev libxine2-dev libxine2 libswscale-dev libswscale-ffmpeg3 libdc1394-22 libdc1394-22-dev libdc1394-utils -y

echo "codecs"
sudo apt-get install libavcodec-dev -y
sudo apt-get install libfaac-dev libmp3lame-dev -y
sudo apt-get install libopencore-amrnb-dev libopencore-amrwb-dev -y
sudo apt-get install libtheora-dev libvorbis-dev libxvidcore-dev -y
sudo apt-get install ffmpeg x264 libx264-dev -y
sudo apt-get install libv4l-0 libv4l v4l-utils -y

echo "multiproccessing library"
sudo apt-get install libtbb-dev -y

echo "finally download and install opencv"
mkdir opencv
cd opencv
wget "https://github.com/opencv/opencv/archive/2.4.13.2.zip"
unzip opencv-2.4.13.2.zip

cd opencv-2.4.13.2
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=RELEASE \
 -DCMAKE_INSTALL_PREFIX=/usr/local \
 -DINSTALL_C_EXAMPLES=ON \
 -DINSTALL_PYTHON_EXAMPLES=ON \
 -DBUILD_EXAMPLES=ON \
 -DBUILD_opencv_cvv=OFF \
 -DBUILD_NEW_PYTHON_SUPPORT=ON \
 -DWITH_TBB=ON \
 -DWITH_V4L=ON \
 -DWITH_QT=ON \
 -DWITH_OPENGL=ON \
 -DWITH_VTK=ON ..

echo "making and installing"
make -j8
sudo make install

echo "finishing off installation"
sudo /bin/bash -c 'echo "/usr/local/lib" > /etc/ld.so.conf.d/opencv.conf'
sudo ldconfig

echo "Congratulations! You have just installed OpenCV. And that's all, folks! :P"

P.S. Create a script file out of this and then just execute the script file, rather than copy-pasting it line by line into the terminal. You can do that by copying all of it, placing it in a file with the extension .sh, and then simply running that .sh file from the terminal using $ ./filename.sh

sudo apt-get install build-essential cmake git pkg-config
sudo apt-get install libjpeg8-dev libtiff4-dev libjasper-dev libpng12-dev
sudo apt-get install libgtk2.0-dev
sudo apt-get install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev
sudo apt-get install libatlas-base-dev gfortran
sudo apt-get install python2.7-dev
sudo pip install numpy
sudo apt-get install python-opencv

Then you can have a try:

$ python
Python 2.7.6 (default, Oct 26 2016, 20:30:19) 
[GCC 4.8.4] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import cv
>>> import cv2