Eclipse IDE for C/C++ Developers - OpenCV 4.2.0 配置

Eclipse IDE for C/C++ Developers - OpenCV 4.2.0 配置

OpenCV 4.2.0 - Modules
https://docs.opencv.org/4.2.0/index.html

OpenCV 4.2.0 - Tutorials
https://docs.opencv.org/4.2.0/d9/df8/tutorial_root.html

0. Using OpenCV with Eclipse (plugin CDT)

OpenCV modules -> OpenCV Tutorials -> Introduction to OpenCV
https://docs.opencv.org/4.2.0/d7/d16/tutorial_linux_eclipse.html

Eclipse CDT (C/C++ Development Tooling)

1. Prerequisites

prerequisite [ˌpriːˈrekwəzɪt]：n. 先决条件，前提，必备条件

Eclipse IDE
https://www.eclipse.org/

OpenCV 4.2.0 installation in Linux
https://docs.opencv.org/4.2.0/d7/d9f/tutorial_linux_install.html

Eclipse IDE for C/C++ Developers
https://www.eclipse.org/downloads/packages/

2. Making a project

1. Start Eclipse.

2. Go to File -> New -> C/C++ Project
   

3. Choose a name for your project (i.e. DisplayImage). An Empty Project should be okay for this example.
   

4. Leave everything else by default. Press Finish.

5. Your project (in this case DisplayImage) should appear in the Project Navigator (usually at the left side of your window).
   

6. Now, let’s add a source file using OpenCV:

• Right click on DisplayImage (in the Navigator). New -> Folder.
  

• 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
  

7. 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):

//============================================================================
// Name        : using namespace cv;
// Author      : Yongqiang Cheng
// Version     : Feb 22, 2020
// Copyright   : Copyright (c) 2019 Yongqiang Cheng
// Description : Hello World in C++, Ansi-style
//============================================================================

#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;
}

8. We are only missing one final step: To tell OpenCV where the OpenCV headers and libraries are.

fatal error: opencv2/opencv.hpp: No such file or directory

• 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.

/usr/local/include
/usr/local/include/opencv4
/usr/local/include/opencv4/opencv2

If you do not know where your opencv files are, open the Terminal and type:

pkg-config --cflags opencv  // opencv 2.x, opencv 3.x
pkg-config --cflags opencv4 // opencv 4.x

For instance, that command gave me this output:

strong@foreverstrong:~$ pkg-config --cflags opencv4
-I/usr/local/include/opencv4/opencv -I/usr/local/include/opencv4
strong@foreverstrong:~$

• 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_gapi opencv_stitching opencv_face opencv_dnn_superres opencv_surface_matching opencv_quality opencv_reg opencv_stereo opencv_tracking opencv_videostab opencv_rgbd opencv_freetype opencv_dpm opencv_ccalib opencv_saliency opencv_hfs opencv_hdf opencv_line_descriptor opencv_structured_light opencv_viz opencv_phase_unwrapping opencv_xobjdetect opencv_objdetect opencv_superres opencv_optflow opencv_ximgproc opencv_sfm opencv_xfeatures2d opencv_plot opencv_xphoto opencv_photo opencv_fuzzy opencv_bgsegm opencv_video opencv_aruco opencv_datasets opencv_text opencv_ml opencv_cvv opencv_dnn_objdetect opencv_dnn opencv_bioinspired opencv_highgui opencv_videoio opencv_imgcodecs opencv_shape opencv_calib3d opencv_features2d opencv_flann opencv_img_hash opencv_imgproc opencv_core

opencv_core
opencv_imgproc
opencv_img_hash
opencv_flann
opencv_features2d
opencv_imgcodecs
opencv_shape
opencv_calib3d
opencv_dnn
opencv_bioinspired
opencv_highgui
opencv_videoio
opencv_datasets
opencv_text
opencv_ml
opencv_cvv
opencv_dnn_objdetect
opencv_video
opencv_aruco
......

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:

pkg-config --libs opencv  // opencv 2.x, opencv 3.x
pkg-config --libs opencv4 // opencv 4.x

My output (in case you want to check) was:

strong@foreverstrong:~$ pkg-config --libs opencv4
-L/usr/local/lib -lopencv_gapi -lopencv_stitching -lopencv_face -lopencv_dnn_superres -lopencv_surface_matching -lopencv_quality -lopencv_reg -lopencv_stereo -lopencv_tracking -lopencv_videostab -lopencv_rgbd -lopencv_freetype -lopencv_dpm -lopencv_ccalib -lopencv_saliency -lopencv_hfs -lopencv_hdf -lopencv_line_descriptor -lopencv_structured_light -lopencv_viz -lopencv_phase_unwrapping -lopencv_xobjdetect -lopencv_objdetect -lopencv_superres -lopencv_optflow -lopencv_ximgproc -lopencv_sfm -lopencv_xfeatures2d -lopencv_plot -lopencv_xphoto -lopencv_photo -lopencv_fuzzy -lopencv_bgsegm -lopencv_video -lopencv_aruco -lopencv_datasets -lopencv_text -lopencv_ml -lopencv_cvv -lopencv_dnn_objdetect -lopencv_dnn -lopencv_bioinspired -lopencv_highgui -lopencv_videoio -lopencv_imgcodecs -lopencv_shape -lopencv_calib3d -lopencv_features2d -lopencv_flann -lopencv_img_hash -lopencv_imgproc -lopencv_core
strong@foreverstrong:~$

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

16:21:55 **** Build of configuration Debug for project DisplayImage ****
make all 
Building file: ../src/DisplayImage.cpp
Invoking: GCC C++ Compiler
g++ -std=c++0x -I/usr/local/include -I/usr/local/include/opencv4 -I/usr/local/include/opencv4/opencv2 -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/DisplayImage.d" -MT"src/DisplayImage.o" -o "src/DisplayImage.o" "../src/DisplayImage.cpp"
Finished building: ../src/DisplayImage.cpp
 
Building target: DisplayImage
Invoking: GCC C++ Linker
g++ -L/usr/local/lib -o "DisplayImage"  ./src/DisplayImage.o   -lopencv_core -lopencv_video -lopencv_ml -lopencv_imgproc -lopencv_img_hash -lopencv_flann -lopencv_features2d -lopencv_calib3d -lopencv_dnn -lopencv_dnn_objdetect -lopencv_cvv -lopencv_text -lopencv_datasets -lopencv_aruco -lopencv_bgsegm -lopencv_shape -lopencv_imgcodecs -lopencv_videoio -lopencv_highgui -lopencv_bioinspired
Finished building target: DisplayImage
 

16:21:58 Build Finished (took 2s.981ms)

If you check in your folder, there should be an executable there.

strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ pwd
/home/strong/eclipse-work/DisplayImage/Debug
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ 
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ ls -l ./DisplayImage 
-rwxrwxr-x 1 strong strong 714808 Feb 22 16:21 ./DisplayImage
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ 

3. 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:

cd 
cd debug
./DisplayImage ../images/person.jpg

strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ pwd
/home/strong/eclipse-work/DisplayImage/Debug
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ 
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ ls -l ./DisplayImage 
-rwxrwxr-x 1 strong strong 714808 Feb 22 16:21 ./DisplayImage
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ 
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$ ./DisplayImage ../images/person.jpg 
QXcbConnection: XCB error: 148 (Unknown), sequence: 172, resource id: 0, major code: 140 (Unknown), minor code: 20
strong@foreverstrong:~/eclipse-work/DisplayImage/Debug$

Assuming that the image to use as the argument would be located in /images/person.png. We can still do this, but let’s do it from Eclipse:

1. Go to Run -> Run Configurations

2. 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).
   

3. 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).
   

4. Click on the Apply button and then in Run. An OpenCV window should pop up with the fish image (or whatever you used).

5. Congratulations! You are ready to have fun with OpenCV using Eclipse.

QXcbConnection: XCB error: 148 (Unknown), sequence: 172, resource id: 0, major code: 140 (Unknown), minor code: 20

4. Example

//============================================================================
// Name        : using namespace cv;
// Author      : Yongqiang Cheng
// Version     : Feb 22, 2020
// Copyright   : Copyright (c) 2019 Yongqiang Cheng
// Description : Hello World in C++, Ansi-style
//============================================================================

#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;
}

18:54:46 **** Build of configuration Debug for project DisplayImage ****
make all 
Building file: ../src/DisplayImage.cpp
Invoking: GCC C++ Compiler
g++ -std=c++0x -I/usr/local/include -I/usr/local/include/opencv4 -I/usr/local/include/opencv4/opencv2 -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"src/DisplayImage.d" -MT"src/DisplayImage.o" -o "src/DisplayImage.o" "../src/DisplayImage.cpp"
Finished building: ../src/DisplayImage.cpp
 
Building target: DisplayImage
Invoking: GCC C++ Linker
g++ -L/usr/local/lib -o "DisplayImage"  ./src/DisplayImage.o   -lopencv_core -lopencv_video -lopencv_ml -lopencv_imgproc -lopencv_img_hash -lopencv_flann -lopencv_features2d -lopencv_calib3d -lopencv_dnn -lopencv_dnn_objdetect -lopencv_cvv -lopencv_text -lopencv_datasets -lopencv_aruco -lopencv_bgsegm -lopencv_shape -lopencv_imgcodecs -lopencv_videoio -lopencv_highgui -lopencv_bioinspired
Finished building target: DisplayImage
 

18:54:49 Build Finished (took 3s.139ms)