initial commit

doc/tutorials/introduction/linux_eclipse/linux_eclipse.markdown

@@ -0,0 +1,199 @@
+Using OpenCV with Eclipse (plugin CDT) {#tutorial_linux_eclipse}
+======================================
+
+Prerequisites
+-------------
+Two ways, one by forming a project directly, and another by CMake Prerequisites
+-#  Having installed [Eclipse](http://www.eclipse.org/) 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](http://www.eclipse.org/downloads/packages/eclipse-ide-cc-developers/heliossr2) .
+        Choose the link according to your workstation.
+-#  Having installed OpenCV. If not yet, go @ref tutorial_linux_install "here".
+
+Making a project
+----------------
+
+-#  Start Eclipse. Just run the executable that comes in the folder.
+-#  Go to **File -\> New -\> C/C++ Project**
+
+    ![](images/a0.png)
+
+-#  Choose a name for your project (i.e. DisplayImage). An **Empty Project** should be okay for this
+    example.
+
+    ![](images/a1.png)
+
+-#  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).
+
+    ![](images/a3.png)
+
+-#  Now, let's add a source file using OpenCV:
+    -   Right click on **DisplayImage** (in the Navigator). **New -\> Folder** .
+
+        ![](images/a4.png)
+
+    -   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**
+
+        ![](images/a7.png)
+
+-#  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{.cpp}
+    #include <opencv2/opencv.hpp>
+
+    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;
+    }
+    @endcode
+-#  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:
+        -#  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.
+
+            ![](images/a9.png)
+
+            @note If you do not know where your opencv files are, open the **Terminal** and type:
+            @code{.bash}
+            pkg-config --cflags opencv
+            @endcode
+            For instance, that command gave me this output:
+            @code{.bash}
+            -I/usr/local/include/opencv -I/usr/local/include
+            @endcode
+
+        -#  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 4 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_imgcodecs opencv_highgui opencv_ml opencv_videoio opencv_video opencv_features2d
+            opencv_calib3d opencv_objdetect opencv_flann
+
+            ![](images/a10.png)
+
+            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{.bash}
+            pkg-config --libs opencv
+            @endcode
+            My output (in case you want to check) was:
+            @code{.bash}
+            -L/usr/local/lib -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_videoio -lopencv_imgcodecs -lopencv_flann
+            @endcode
+            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
+
+    ![](images/a12.png)
+
+    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{.bash}
+cd <DisplayImage_directory>
+cd src
+./DisplayImage ../images/HappyLittleFish.png
+@endcode
+Assuming that the image to use as the argument would be located in
+\<DisplayImage_directory\>/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**:
+
+    ![](images/a14.png)
+
+-#  Click on the **Apply** button and then in Run. An OpenCV window should pop up with the fish
+    image (or whatever you used).
+
+    ![](images/a15.jpg)
+
+-#  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{.cpp}
+#include <opencv2/opencv.hpp>
+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;
+}
+@endcode
+-#  Create a build directory, say, under *foo*: mkdir /build. Then cd build.
+-#  Put a `CmakeLists.txt` file in build:
+@code{.bash}
+PROJECT( helloworld_proj )
+FIND_PACKAGE( OpenCV REQUIRED )
+ADD_EXECUTABLE( helloworld helloworld.cxx )
+TARGET_LINK_LIBRARIES( helloworld \f${OpenCV_LIBS} )
+@endcode
+-#  Run: cmake-gui .. and make sure you fill in where opencv was built.
+-#  Then click configure and then generate. If it's OK, **quit cmake-gui**
+-#  Run `make -j4` (the -j4 is optional, it just tells the compiler to build in 4 threads). Make
+    sure it builds.
+-#  Start eclipse. Put the workspace in some directory but **not** in foo or `foo\build`
+-#  Right click in the Project Explorer section. Select Import And then open the C/C++ filter.
+    Choose *Existing Code* as a Makefile Project.
+-#  Name your project, say *helloworld*. Browse to the Existing Code location `foo\build` (where
+    you ran your cmake-gui from). Select *Linux GCC* in the *"Toolchain for Indexer Settings"* and
+    press *Finish*.
+-#  Right click in the Project Explorer section. Select Properties. Under C/C++ Build, set the
+    *build directory:* from something like `${workspace_loc:/helloworld}` to
+    `${workspace_loc:/helloworld}/build` since that's where you are building to.
+
+    -#  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!