OpenCV + extra modules install script for Ubuntu 16.04

install-opencv.sh

#!/bin/bash

# https://gist.github.com/a-sync/276fbb5776ad5d5775d1bd6205e22a4a

OPENCV_VERSION="3.4.3"

read -p "Install/update dependencies? ([Yy] or skip this step) " -n 1 -r
echo 
if [[ $REPLY =~ ^[Yy]$ ]]
then
    sudo apt-get -y update
    #sudo apt-get -y upgrade
    #sudo apt-get -y dist-upgrade
    #sudo apt-get -y autoremove

    sudo apt-get install -y curl tar build-essential cmake pkg-config python-dev python3-dev python-numpy python3-numpy v4l-utils x264
    sudo apt-get install -y zlib1g-dev yasm libatlas-base-dev gfortran libeigen3-dev libgflags-dev libhdf5-dev libgphoto2-dev libv4l-dev libprotobuf-dev protobuf-compiler
    sudo apt-get install -y libjpeg8-dev libwebp-dev libtiff5-dev libjasper-dev libpng12-dev libavcodec-dev libavformat-dev libswscale-dev libdc1394-22-dev libtheora-dev libvorbis-dev libxvidcore-dev libx264-dev
fi

if [ ! -d "opencv-v$OPENCV_VERSION" ]
then
    mkdir "opencv-v$OPENCV_VERSION"
    curl -L "https://github.com/opencv/opencv/archive/$OPENCV_VERSION.tar.gz" | tar xz --strip=1 -C "opencv-v$OPENCV_VERSION"
fi

if [ ! -d "opencv_contrib-v$OPENCV_VERSION" ]
then
    mkdir "opencv_contrib-v$OPENCV_VERSION"
    curl -L "https://github.com/opencv/opencv_contrib/archive/$OPENCV_VERSION.tar.gz" | tar xz --strip=1 -C "opencv_contrib-v$OPENCV_VERSION"
fi

cd "opencv-v$OPENCV_VERSION"
rm -rf build
mkdir build
cd build
cmake -DCMAKE_BUILD_TYPE=RELEASE \
      -DOPENCV_ENABLE_NONFREE=ON \
      -DCMAKE_INSTALL_PREFIX=/usr/local \
      -DOPENCV_EXTRA_MODULES_PATH="../../opencv_contrib-v$OPENCV_VERSION/modules" \
      -DBUILD_TESTS=OFF \
      -DBUILD_PERF_TESTS=OFF \
      -DBUILD_JAVA=OFF ..
#-DCMAKE_CXX_FLAGS=-std=c++11 

read -p "Compile and install? ([Yy] or skip this step) " -n 1 -r
echo 
if [[ $REPLY =~ ^[Yy]$ ]]
then
    make -j4
    #make -j$(nproc + 1)

    sudo make install
    sudo ldconfig
fi

echo C libs:
pkg-config --cflags opencv
pkg-config --modversion opencv

echo Python libs: 
find /usr/local/lib/ -type f -name "cv2*.so"
python -c 'import cv2; print("python "+cv2.__version__)'
python3 -c 'import cv2; print("python3 "+cv2.__version__)'