1 Using OpenCV with Eclipse (plugin CDT) {#tutorial_linux_eclipse} 2 ====================================== 3 4 Prerequisites 5 ------------- 6 Two ways, one by forming a project directly, and another by CMake Prerequisites 7 -# Having installed [Eclipse](http://www.eclipse.org/) in your workstation (only the CDT plugin for 8 C/C++ is needed). You can follow the following steps: 9 - Go to the Eclipse site 10 - Download [Eclipse IDE for C/C++ 11 Developers](http://www.eclipse.org/downloads/packages/eclipse-ide-cc-developers/heliossr2) . 12 Choose the link according to your workstation. 13 -# Having installed OpenCV. If not yet, go @ref tutorial_linux_install "here". 14 15 Making a project 16 ---------------- 17 18 -# Start Eclipse. Just run the executable that comes in the folder. 19 -# Go to **File -\> New -\> C/C++ Project** 20 21  22 23 -# Choose a name for your project (i.e. DisplayImage). An **Empty Project** should be okay for this 24 example. 25 26  27 28 -# Leave everything else by default. Press **Finish**. 29 -# Your project (in this case DisplayImage) should appear in the **Project Navigator** (usually at 30 the left side of your window). 31 32  33 34 -# Now, let's add a source file using OpenCV: 35 - Right click on **DisplayImage** (in the Navigator). **New -\> Folder** . 36 37  38 39 - Name your folder **src** and then hit **Finish** 40 - Right click on your newly created **src** folder. Choose **New source file**: 41 - Call it **DisplayImage.cpp**. Hit **Finish** 42 43  44 45 -# So, now you have a project with a empty .cpp file. Let's fill it with some sample code (in other 46 words, copy and paste the snippet below): 47 @code{.cpp} 48 #include <opencv2/opencv.hpp> 49 50 using namespace cv; 51 52 int main( int argc, char** argv ) 53 { 54 Mat image; 55 image = imread( argv[1], 1 ); 56 57 if( argc != 2 || !image.data ) 58 { 59 printf( "No image data \n" ); 60 return -1; 61 } 62 63 namedWindow( "Display Image", WINDOW_AUTOSIZE ); 64 imshow( "Display Image", image ); 65 66 waitKey(0); 67 68 return 0; 69 } 70 @endcode 71 -# We are only missing one final step: To tell OpenCV where the OpenCV headers and libraries are. 72 For this, do the following: 73 74 - Go to **Project--\>Properties** 75 - In **C/C++ Build**, click on **Settings**. At the right, choose the **Tool Settings** Tab. 76 Here we will enter the headers and libraries info: 77 -# In **GCC C++ Compiler**, go to **Includes**. In **Include paths(-l)** you should 78 include the path of the folder where opencv was installed. In our example, this is 79 /usr/local/include/opencv. 80 81  82 83 @note If you do not know where your opencv files are, open the **Terminal** and type: 84 @code{.bash} 85 pkg-config --cflags opencv 86 @endcode 87 For instance, that command gave me this output: 88 @code{.bash} 89 -I/usr/local/include/opencv -I/usr/local/include 90 @endcode 91 92 -# Now go to **GCC C++ Linker**,there you have to fill two spaces: 93 94 First in **Library search path (-L)** you have to write the path to where the opencv libraries 95 reside, in my case the path is: : 96 97 /usr/local/lib 98 99 Then in **Libraries(-l)** add the OpenCV libraries that you may need. Usually just the 3 first 100 on the list below are enough (for simple applications) . In my case, I am putting all of them 101 since I plan to use the whole bunch: 102 103 opencv_core opencv_imgproc opencv_highgui opencv_ml opencv_video opencv_features2d 104 opencv_calib3d opencv_objdetect opencv_contrib opencv_legacy opencv_flann 105 106  107 108 If you don't know where your libraries are (or you are just psychotic and want to make sure 109 the path is fine), type in **Terminal**: 110 @code{.bash} 111 pkg-config --libs opencv 112 @endcode 113 My output (in case you want to check) was: 114 @code{.bash} 115 -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 116 @endcode 117 Now you are done. Click **OK** 118 119 - Your project should be ready to be built. For this, go to **Project-\>Build all** 120 121 In the Console you should get something like 122 123  124 125 If you check in your folder, there should be an executable there. 126 127 Running the executable 128 ---------------------- 129 130 So, now we have an executable ready to run. If we were to use the Terminal, we would probably do 131 something like: 132 @code{.bash} 133 cd <DisplayImage_directory> 134 cd src 135 ./DisplayImage ../images/HappyLittleFish.png 136 @endcode 137 Assuming that the image to use as the argument would be located in 138 \<DisplayImage_directory\>/images/HappyLittleFish.png. We can still do this, but let's do it from 139 Eclipse: 140 141 -# Go to **Run-\>Run Configurations** 142 -# Under C/C++ Application you will see the name of your executable + Debug (if not, click over 143 C/C++ Application a couple of times). Select the name (in this case **DisplayImage Debug**). 144 -# Now, in the right side of the window, choose the **Arguments** Tab. Write the path of the image 145 file we want to open (path relative to the workspace/DisplayImage folder). Let's use 146 **HappyLittleFish.png**: 147 148  149 150 -# Click on the **Apply** button and then in Run. An OpenCV window should pop up with the fish 151 image (or whatever you used). 152 153  154 155 -# Congratulations! You are ready to have fun with OpenCV using Eclipse. 156 157 ### V2: Using CMake+OpenCV with Eclipse (plugin CDT) 158 159 Say you have or create a new file, *helloworld.cpp* in a directory called *foo*: 160 @code{.cpp} 161 #include <opencv2/opencv.hpp> 162 using namespace cv; 163 164 int main ( int argc, char **argv ) 165 { 166 Mat img(480, 640, CV_8U); 167 putText(img, "Hello World!", Point( 200, 400 ), FONT_HERSHEY_SIMPLEX | FONT_ITALIC, 1.0, Scalar( 255, 255, 0 )); 168 imshow("My Window", img); 169 waitKey(); 170 return 0; 171 } 172 @endcode 173 -# Create a build directory, say, under *foo*: mkdir /build. Then cd build. 174 -# Put a `CmakeLists.txt` file in build: 175 @code{.bash} 176 PROJECT( helloworld_proj ) 177 FIND_PACKAGE( OpenCV REQUIRED ) 178 ADD_EXECUTABLE( helloworld helloworld.cxx ) 179 TARGET_LINK_LIBRARIES( helloworld \f${OpenCV_LIBS} ) 180 @endcode 181 -# Run: cmake-gui .. and make sure you fill in where opencv was built. 182 -# Then click configure and then generate. If it's OK, **quit cmake-gui** 183 -# Run `make -j4` (the -j4 is optional, it just tells the compiler to build in 4 threads). Make 184 sure it builds. 185 -# Start eclipse. Put the workspace in some directory but **not** in foo or `foo\build` 186 -# Right click in the Project Explorer section. Select Import And then open the C/C++ filter. 187 Choose *Existing Code* as a Makefile Project. 188 -# Name your project, say *helloworld*. Browse to the Existing Code location `foo\build` (where 189 you ran your cmake-gui from). Select *Linux GCC* in the *"Toolchain for Indexer Settings"* and 190 press *Finish*. 191 -# Right click in the Project Explorer section. Select Properties. Under C/C++ Build, set the 192 *build directory:* from something like `${workspace_loc:/helloworld}` to 193 `${workspace_loc:/helloworld}/build` since that's where you are building to. 194 195 -# You can also optionally modify the Build command: from make to something like 196 `make VERBOSE=1 -j4` which tells the compiler to produce detailed symbol files for debugging and 197 also to compile in 4 parallel threads. 198 199 -# Done! 200
