.. _Linux_Eclipse_Usage: Using OpenCV with Eclipse (plugin CDT) **************************************** .. note:: Two ways, one by forming a project directly, and another by CMake Prerequisites =============== 1. Having installed `Eclipse `_ in your workstation (only the CDT plugin for C/C++ is needed). You can follow the following steps: * Go to the Eclipse site * Download `Eclipse IDE for C/C++ Developers `_ . Choose the link according to your workstation. #. Having installed OpenCV. If not yet, go :ref:`here `. Making a project ================= 1. Start Eclipse. Just run the executable that comes in the folder. #. Go to **File -> New -> C/C++ Project** .. image:: images/a0.png :alt: Eclipse Tutorial Screenshot 0 :align: center #. Choose a name for your project (i.e. DisplayImage). An **Empty Project** should be okay for this example. .. image:: images/a1.png :alt: Eclipse Tutorial Screenshot 1 :align: center #. Leave everything else by default. Press **Finish**. #. Your project (in this case DisplayImage) should appear in the **Project Navigator** (usually at the left side of your window). .. image:: images/a3.png :alt: Eclipse Tutorial Screenshot 3 :align: center #. Now, let's add a source file using OpenCV: * Right click on **DisplayImage** (in the Navigator). **New -> Folder** . .. image:: images/a4.png :alt: Eclipse Tutorial Screenshot 4 :align: center * Name your folder **src** and then hit **Finish** * Right click on your newly created **src** folder. Choose **New source file**: * Call it **DisplayImage.cpp**. Hit **Finish** .. image:: images/a7.png :alt: Eclipse Tutorial Screenshot 7 :align: center #. So, now you have a project with a empty .cpp file. Let's fill it with some sample code (in other words, copy and paste the snippet below): .. code-block:: cpp #include using namespace cv; int main( int argc, char** argv ) { Mat image; image = imread( argv[1], 1 ); if( argc != 2 || !image.data ) { printf( "No image data \n" ); return -1; } namedWindow( "Display Image", WINDOW_AUTOSIZE ); imshow( "Display Image", image ); waitKey(0); return 0; } #. We are only missing one final step: To tell OpenCV where the OpenCV headers and libraries are. For this, do the following: * Go to **Project-->Properties** * In **C/C++ Build**, click on **Settings**. At the right, choose the **Tool Settings** Tab. Here we will enter the headers and libraries info: a. In **GCC C++ Compiler**, go to **Includes**. In **Include paths(-l)** you should include the path of the folder where opencv was installed. In our example, this is ``/usr/local/include/opencv``. .. image:: images/a9.png :alt: Eclipse Tutorial Screenshot 9 :align: center .. note:: If you do not know where your opencv files are, open the **Terminal** and type: .. code-block:: bash pkg-config --cflags opencv For instance, that command gave me this output: .. code-block:: bash -I/usr/local/include/opencv -I/usr/local/include b. Now go to **GCC C++ Linker**,there you have to fill two spaces: First in **Library search path (-L)** you have to write the path to where the opencv libraries reside, in my case the path is: :: /usr/local/lib Then in **Libraries(-l)** add the OpenCV libraries that you may need. Usually just the 3 first on the list below are enough (for simple applications) . In my case, I am putting all of them since I plan to use the whole bunch: opencv_core opencv_imgproc opencv_highgui opencv_ml opencv_video opencv_features2d opencv_calib3d opencv_objdetect opencv_contrib opencv_legacy opencv_flann .. image:: images/a10.png :alt: Eclipse Tutorial Screenshot 10 :align: center If you don't know where your libraries are (or you are just psychotic and want to make sure the path is fine), type in **Terminal**: .. code-block:: bash pkg-config --libs opencv My output (in case you want to check) was: .. code-block:: bash -L/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann Now you are done. Click **OK** * Your project should be ready to be built. For this, go to **Project->Build all** In the Console you should get something like .. image:: images/a12.png :alt: Eclipse Tutorial Screenshot 12 :align: center If you check in your folder, there should be an executable there. Running the executable ======================== So, now we have an executable ready to run. If we were to use the Terminal, we would probably do something like: .. code-block:: bash cd cd src ./DisplayImage ../images/HappyLittleFish.png Assuming that the image to use as the argument would be located in /images/HappyLittleFish.png. We can still do this, but let's do it from Eclipse: #. Go to **Run->Run Configurations** #. Under C/C++ Application you will see the name of your executable + Debug (if not, click over C/C++ Application a couple of times). Select the name (in this case **DisplayImage Debug**). #. Now, in the right side of the window, choose the **Arguments** Tab. Write the path of the image file we want to open (path relative to the workspace/DisplayImage folder). Let's use **HappyLittleFish.png**: .. image:: images/a14.png :alt: Eclipse Tutorial Screenshot 14 :align: center #. Click on the **Apply** button and then in Run. An OpenCV window should pop up with the fish image (or whatever you used). .. image:: images/a15.jpg :alt: Eclipse Tutorial Screenshot 15 :align: center #. Congratulations! You are ready to have fun with OpenCV using Eclipse. ================================================== V2: Using CMake+OpenCV with Eclipse (plugin CDT) ================================================== Say you have or create a new file, *helloworld.cpp* in a directory called *foo*: .. code-block:: cpp #include using namespace cv; int main ( int argc, char **argv ) { Mat img(480, 640, CV_8U); putText(img, "Hello World!", Point( 200, 400 ), FONT_HERSHEY_SIMPLEX | FONT_ITALIC, 1.0, Scalar( 255, 255, 0 )); imshow("My Window", img); waitKey(); return 0; } 1. Create a build directory, say, under *foo*: ``mkdir /build``. Then ``cd build``. #. Put a *CmakeLists.txt* file in build: .. code-block:: bash PROJECT( helloworld_proj ) FIND_PACKAGE( OpenCV REQUIRED ) ADD_EXECUTABLE( helloworld helloworld.cxx ) TARGET_LINK_LIBRARIES( helloworld ${OpenCV_LIBS} ) #. Run: ``cmake-gui ..`` and make sure you fill in where opencv was built. #. Then click ``configure`` and then ``generate``. If it's OK, **quit cmake-gui** #. Run ``make -j4`` *(the ``-j4`` is optional, it just tells the compiler to build in 4 threads)*. Make sure it builds. #. Start ``eclipse`` . Put the workspace in some directory but **not** in ``foo`` or ``foo\\build`` #. Right click in the ``Project Explorer`` section. Select ``Import`` And then open the ``C/C++`` filter. Choose *Existing Code* as a Makefile Project`` #. Name your project, say *helloworld*. Browse to the Existing Code location ``foo\\build`` (where you ran your cmake-gui from). Select *Linux GCC* in the *"Toolchain for Indexer Settings"* and press *Finish*. #. Right click in the ``Project Explorer`` section. Select ``Properties``. Under ``C/C++ Build``, set the *build directory:* from something like ``${workspace_loc:/helloworld}`` to ``${workspace_loc:/helloworld}/build`` since that's where you are building to. a. You can also optionally modify the ``Build command:`` from ``make`` to something like ``make VERBOSE=1 -j4`` which tells the compiler to produce detailed symbol files for debugging and also to compile in 4 parallel threads. #. Done!