Jtdcftul

I knew this question has answers.Eventhough I tried different websites to install after performing installation to ensure the opencv version and library path,I compiled pkg-config... and pkg cflags... command,but console display as,
////Package opencv was not found in the pkg-config search path.
Perhaps you should add the directory containing `opencv.pc'
to the PKG_CONFIG_PATH environment variable
No package 'opencv' found////
I need simple and easy steps with clear to install opencv4 in c++ IF anyone know guide me to install this one.

Installing OpenCV4 on Ubuntu can be achieved in two ways:

• Through pre-built binaries which are already available in Ubuntu repositories


• By compiling it from the source

Section - I: Installing through pre-built Binaries

• You need to install the python-opencv package using the command:

$ sudo apt-get install python-opencv

• Open Python IDLE (or IPython) and execute the following codes in Python terminal:

import cv2 as cv
print(cv.__version__)

Note: - In here, you might not get the latest version. With respect to Python API, the latest version will always contain much better support and latest bug fixes.

So, if you wish to get the latest source codes, compile the source. Let's head over to the next section.

Section - II: Compiling from Source

• Installing Required Dependencies: We would use CMake to configure the installation, GCC for compilation, and lastly both the Python-devel and Numpy for building Python bindings etc. Here are the commands:

sudo apt-get install cmake
sudo apt-get install python-devel numpy
sudo apt-get install gcc gcc-c++

We also require GTK support for GUI features, Camera support (libv4l), Media Support (ffmpeg, gstreamer) etc. Execute the commands as follows:

sudo apt-get install gtk2-devel
sudo apt-get install libv4l-devel
sudo apt-get install ffmpeg-devel
sudo apt-get install gstreamer-plugins-base-devel

• Installing Optional Dependencies: It's not a mandate to install these dependencies. It totally depends on your requirements. In case you wish to install, execute these commands:

sudo apt-get install libpng-devel
sudo apt-get install libjpeg-turbo-devel
sudo apt-get install jasper-devel
sudo apt-get install openexr-devel
sudo apt-get install libtiff-devel
sudo apt-get install libwebp-devel

• Download OpenCV from the Github repository. Install Git using the commands:

$ sudo apt-get install git
$ git clone https://github.com/opencv/opencv.git

You will get a new folder - opencv in your current directory. Cloning might take some time, so have patience. Once done, open a new terminal window and navigate to the latest downloaded "opencv" folder. Create a new build folder and navigate to it:

$ mkdir build
$ cd build

• Configuration & Installation: Having all dependencies, we can finally install OpenCV. The installation has to be configured with CMake as it specifies which modules are to be installed, installation path, which additional libraries to be used, whether documentation and examples to be compiled etc. Most of this work is done automatically with well-configured default parameters.

You can use the following command to configure OpenCV library build (executed from build folder):

$ cmake ../

Note: OpenCV defaults assume "Release" build type and installation path is "/usr/local".

While the execution process is ON, you might notice these lines in your CMake output indicating that Python is properly found:

--   Python 2:

--     Interpreter:                 /usr/bin/python2.7 (ver 2.7.6)



--     Libraries:                   /usr/lib/x86_64-linux-gnu/libpython2.7.so (ver 2.7.6)



--     numpy:                       /usr/lib/python2.7/dist-packages/numpy/core/include (ver 1.8.2)



--     packages path:               lib/python2.7/dist-packages



--



--   Python 3:

--     Interpreter:                 /usr/bin/python3.4 (ver 3.4.3)

--     Libraries:                   /usr/lib/x86_64-linux-gnu/libpython3.4m.so (ver 3.4.3)

--     numpy:                       /usr/lib/python3/dist-packages/numpy/core/include (ver 1.8.2)

--     packages path:               lib/python3.4/dist-packages

Once done, you need to build the files using make command and install it using make install command:

$ make

# sudo make install

Your OpenCV is installed. You can find all your files in the "/usr/local/" folder. Open a terminal and try import "cv2":

import cv2 as cv
print(cv.__version__)

Section - III: Creating a C++ program

• Execute the following commands:

$ mkdir cpp_test

$ cd cpp_test

$ touch main.cpp

The above commands will create a folder called "cpp_test" and will also create a "main.cpp file" inside it.

Now place any .jpeg image inside the cpp_test folder.So Now your cpp_test folder will contain two files:

1. Your Sample.jpeg file


2. 
   

   Main.cpp file

   
   
   
   
   
   • Now open your "Main.cpp" file and type the below given C++ program:
   
   
   
   

• Once done, you need to compile your code using the following command:

g++ main.cpp -o output pkg-config --cflags --libs opencv

Note: Do include the ` given in the above command. Its a part of it.

• Post compilation, run your C++ program using the command:

$ ./output