Orange Segregation

CV2 is used to identify colour of orange and arduino is used to actuate servo motors

How to install CV2

To install OpenCV Python module, run the following commands:

	sudo apt update
	sudo apt install python3-opencv

The command above will install all packages necessary to run OpenCV.

python3 -c "import cv2; print(cv2.__version__)"

To verify the installation, import the cv2 module and print the OpenCV version:

output: 3.2.0

Install OpenCV from Source

Start by increasing the swap space to avoid compilation hangups due to memory problems:

sudo nano /etc/dphys-swapfile

Change the CONF_SWAPSIZE value from the default 100 to 1024: /etc/dphys-swapfile

CONF_SWAPSIZE=1024

Save the file and run the following command for changes to take effect:

sudo /etc/init.d/dphys-swapfile restart

We can now start building OpenCV. First, update the packages index and install the build tools and required dependencies:

sudo apt update
sudo apt install build-essential cmake git pkg-config libgtk-3-dev "libcanberra-gtk*"
sudo apt install libavcodec-dev libavformat-dev libswscale-dev libv4l-dev libxvidcore-dev libx264-dev
sudo apt install libjpeg-dev libpng-dev libtiff-dev gfortran openexr libatlas-base-dev opencl-headers
sudo apt install python3-dev python3-numpy libtbb2 libtbb-dev libdc1394-22-dev

Create the build directory

mkdir ~/opencv_build && cd ~/opencv_build
git clone https://github.com/opencv/opencv.git
git clone https://github.com/opencv/opencv_contrib.git

At the time of writing, the default version in the GitHub repositories is version 4.1.1. If you want to install an older version of OpenCV, navigate to both opencv and opencv_contrib directories and run git checkout <opencv-version>. Once the repositories are cloned, create a temporary build directory, and change to it:

  mkdir -p ~/opencv_build/opencv/build && cd ~/opencv_build/opencv/build

Set up the OpenCV build configuration with cmake:

     cmake -D CMAKE_BUILD_TYPE=RELEASE \
        -D CMAKE_INSTALL_PREFIX=/usr/local \
        -D INSTALL_C_EXAMPLES=OFF \
        -D INSTALL_PYTHON_EXAMPLES=OFF \
        -D OPENCV_GENERATE_PKGCONFIG=ON \
        -D ENABLE_NEON=ON \
        -D OPENCV_EXTRA_EXE_LINKER_FLAGS=-latomic \
        -D ENABLE_VFPV3=ON \
        -D BUILD_TESTS=OFF \
        -D OPENCV_ENABLE_NONFREE=ON \
        -D OPENCV_EXTRA_MODULES_PATH=~/opencv_build/opencv_contrib/modules \
        -D BUILD_EXAMPLES=OFF ..

The output will look something like below:

...
-- Configuring done
-- Generating done
-- Build files have been written to: /home/pi/opencv_build/opencv/build

Run make to start the compilation process:

make -j4

The process will take some time, around 1 - 2 hours, depending on the Raspberry Pi model. If the compilation fails at some point, due to resources not available, run the make command again and the process will continue from where it stopped.

When completed you will see something like below:

...
[100%] Linking CXX shared module ../../lib/python3/cv2.cpython-35m-arm-linux-gnueabihf.so
[100%] Built target opencv_python3

The final step is to install compiled OpenCV files:

sudo make install

...
-- Installing: /usr/local/bin/opencv_version
-- Set runtime path of "/usr/local/bin/opencv_version" to "/usr/local/lib"

To check whether OpenCV has been installed successfully type the following commands and you should see the OpenCV version: C++ library:

pkg-config --modversion opencv4

4.1.1

Python library:

python3 -c "import cv2; print(cv2.__version__)"

4.1.1-pre

Clean Up

If you don’t have much free space on your SD card, delete the source files:

rm -rf ~/opencv_build

Heavy swap usage could damage your SD card. Change back the swap space to its original size:

sudo nano /etc/dphys-swapfile

Edit the CONF_SWAPSIZE value to 100:

				     /etc/dphys-swapfile

CONF_SWAPSIZE=100

Copy Save the file and activate the changes:

sudo /etc/init.d/dphys-swapfile restart

Prerequisites

Software and Librarys

• Install ARDUINO IDE
• Install library CircularBuffer. (The clear explanation is given at # rlogiacco/CircularBuffer)