I am trying to begin an opencv project. I have installed all of the dependancies etc.
I am running the following to compile the program
g++ $(pkg-config --cflags --libs opencv4) -std=c++11 main.cpp -o yourFileProgram
inside of main.cpp:
#include "opencv2/imgcodecs.hpp"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/imgproc/imgproc.hpp"
#include <iostream>
cv::RNG rng(12345);
int main(int argc, const char * argv[]) {
return 0;
}
The code compiles, however when I run ./yourFileProgram the exec never terminates.
Related
I have this error when compiling my first gtkmm project.
gtkmmgui.cpp:2:10: fatal error: gtkmm-3.0: No such file or directory
I also tried this:
g++ gtkmmgui.cpp `pkg-config --cflags --libs gtkmm3.0`
but it still doesn't work.
Is this because of wrong #include directory?
Source:
#include <iostream>
#include <gtkmm-3.0>
int main() {
Gtk::Main kit(argc, argv);
Gtk::Window window;
Gtk::Window::run(window)
return 0;
}
There should be nothing like
#include "gtkmm-3.0"
in your source.
Typically all includes look like:
#include <gtkmm/application.h>
#include <gtkmm/window.h>
You should provide also your source code here, because the error is something there! But please reduce it to the minimum where we can see your problem. Please never post all your code which is not related to the problem you ask for.
You also can check if your configuration of gtkmm is correct by simply looking in the output of you pkg-config command. Simply enter it on the command line:
> pkg-config gtkmm-3.0 --cflags
It should be something like:
-I/usr/include/gtkmm-3.0 -I/usr/lib64/gtkmm-3.0/include < a lot more >
EDIT: Your example code is broken in so many parts! Please read the manual of gtkmm!
The following works:
#include <gtkmm/window.h>
#include <gtkmm/main.h>
int main(int argc, char *argv[]) {
Gtk::Main kit(argc, argv);
Gtk::Window window;
kit.run(window);
return 0;
}
compiled and linked with:
g++ `pkg-config gtkmm-3.0 --cflags --libs` main.cpp
I'm trying to compile very simple c++ program by g++ compiler.
//main.cpp
#include <stdio.h>
using namespace std;
typedef pair<int,int> pii;
int main(int argc, char *argv[])
{
printf("Hi");
return 0;
}
But I'm getting compilation error: ‘pair’ does not name a type
Compile line: g++ main.cpp -o main.out
OS: Ubuntu 16.04 lts
g++: gcc version 5.4.0 20160609 (Ubuntu 5.4.0-6ubuntu1~16.04.2)
If I just add #include<iostrem> program compiles and runs successfully:)
#include <stdio.h>
#include<iostream>
using namespace std;
typedef pair<int,int> pii;
int main(int argc, char *argv[])
{
printf("Hi");
return 0;
}
Do you know, why is this happens?
My fault, answer is easy:)
1) For using pair I should include <utility>.
2) <iostream> somewhere includes <utility>, that's why after adding it program compiles successfully:)
I try to use OpenCV C Api in my code. I have opencv and opencv2 folder under usr/include. I can use OpenCV C++ Api. C++ code and compilation&linking commands are below :
#include <iostream>
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/opencv.hpp"
using namespace cv;
int main()
{
Mat im = imread("Sobel.jpg");
return 0;
}
Compile : g++ -c main.cpp
Linking : g++ -o exe main.opkg-config --libs opencv`
Now I want to use OpenCV C-Api. My code is here :
#include <iostream>
#include "opencv/cv.h"
#include "opencv/highgui.h"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/core/core.hpp"
#include "opencv2/opencv.hpp"
using namespace cv;
int main()
{
IplImage* pImg = CvLoadImage("Sobel.jpg");
if(pImg == NULL)
return -1;
// ... big bloat to do the same operations with IplImage
CvShowImage("Image", pImg);
cvWaitKey();
CvReleaseImage(&pImg); // Do not forget to release memory.
// end code here
return 0;
}
When I compile g++ -c main.cpp, the compiler says that ‘CvLoadImage’ was not declared in this scope
A simple spelling mistake, the function prototype is
IplImage* cvLoadImage( const char* filename, int iscolor=CV_LOAD_IMAGE_COLOR );
I know this might be a possible duplicate but I have actually gone through several posts on SO to try and solve this problem
I have the following code in OpenCV and C++
test.cpp
#include "opencv2/core/core_c.h"
#include "opencv2/core/core.hpp"
#include "opencv2/flann/miniflann.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/video.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/ml/ml.hpp"
#include "opencv2/highgui/highgui_c.h"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/contrib/contrib.hpp"
#include <stdio.h>
#include <iostream>
#include <vector>
#include <math.h>
#include <string.h>
#include "draw_shapes.h"
using namespace cv;
using namespace std;
int main(){
Mat normal = imread("/INPUT 2.jpg");
Mat gray;
cvtColor(normal, gray,CV_RGB2GRAY);
Mat binary = gray > 128;
Point start = cv::Point(5.0,5.0);
Point end = cv::Point(200.0,200.0);
draw_line(binary, start, end, 0, 255, 0);
imshow("Draw_Line", binary);
while(waitKey(0)!=27){
;
}
return 0;
}
draw_shapes.cpp
#include "opencv2/core/core_c.h"
#include "opencv2/core/core.hpp"
#include "opencv2/flann/miniflann.hpp"
#include "opencv2/imgproc/imgproc_c.h"
#include "opencv2/imgproc/imgproc.hpp"
#include "opencv2/video/video.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/objdetect/objdetect.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "opencv2/ml/ml.hpp"
#include "opencv2/highgui/highgui_c.h"
#include "opencv2/highgui/highgui.hpp"
#include "opencv2/contrib/contrib.hpp"
#include <stdio.h>
#include <iostream>
#include <vector>
#include <math.h>
#include <string.h>
#include "draw_shapes.h"
void draw_line(cv::Mat img, cv::Point start, cv::Point end, int B, int G, int R){
int thickness = 2;
int lineType = 8;
line(img,start,end,Scalar(B,G,R),thickness,lineType);
}
void draw_rectangle(cv::Mat img, cv::Point p1, cv::Point p2, int B, int G, int R){
int thickness = 2;
int lineType = 8;
rectangle(img, p1, p2, Scalar(B,G,R),thickness, lineType);
}
draw_shapes.h
#ifndef DRAWSHAPES_H
#define DRAWSHAPES_H
void draw_line(cv::Mat, cv::Point, cv::Point, int, int, int);
void draw_rectangle(cv::Mat, cv::Point, cv::Point, int, int, int);
#endif
compile_opencv.sh
#!/bin/bash
echo "compiling $1"
if [[ $1 == *.c ]]
then
gcc -ggdb `pkg-config --cflags opencv` -o `basename $1 .c` $1 `pkg-config --libs opencv`;
elif [[ $1 == *.cpp ]]
then
g++ -ggdb `pkg-config --cflags opencv` -o `basename $1 .cpp` $1 `pkg-config --libs opencv`;
else
echo "Please compile only .c or .cpp files"
fi
echo "Output file => ${1%.*}"
./${1%.*}
I have gone through almost every post on StackOverflow related to header files and including functions from external CPP files and this is what I got.
Now, when I compile, I get
undefined reference to 'draw_line(cv::Mat, cv::Point_<int>, cv::Point_<int>, int, int, int)'
I am taking a wild guess and saying that this might be because I am not compiling draw_shapes.cpp separately, but I tried a simple int add(int x, int y) in a C file and it worked directly. Where am I going wrong here?
(Based on Ben's comment)
This command should work:
g++ -ggdb `pkg-config --cflags opencv` test.cpp draw_shapes.cpp `pkg-config --libs opencv`
Note the backquotes around "pkg-config --cflags opencv" and "pkg-config --libs opencv". Reqular quotes ('), won't work - you really need backquotes here (`). The backquote key is just below the "Esc" key on most keyboards. Or just copy-paste them from your script.
Just as #Ben mentioned, You need to compile the draw_shapes.cpp file. The twist is, if You want to compile Your files separately You need to compile them as objects with -c switch, and then link them together. Further explanation in Your second thread
Here I am with a similar question as the last time, and for which I could not find any answer.
Note that I consider important: Normally I compile my programs in opencv with the next command:
g++ -o def program.cpp `pkg-config --cflags opencv` `pkg-config --libs opencv`
This line will create an executable whose name will be def and that I will be able to use.
I am working in a project, and as it was getting bigger, I had to define some objects, just to make everything easier and possible to handle. I create one object from the files: homogra.cpp and homogra.h the comand I used for it was:
g++ -c homogra.cpp `pkg-config --cflags opencv` `pkg-config --libs opencv`
Then, I wrote in my program.cpp the line #include "homogra.h"
And I compile like:
g++ -o def program.cpp homogra.o `pkg-config --cflags opencv` `pkg-config --libs opencv`
Until now everything is working fine.
Then I create a second object(with the same compilation line as for homogra, but this time with segmentator.cpp and segmentator.h), i wrote the line #include "segmentator.h",(in program.cpp) and I compile like:
g++ -o def program.cpp .o segmentator.o `pkg-config --cflags opencv` `pkg-config --libs opencv`
Now it is not working, and it is not recognising segmentator. I checked already if segmentator was working and everything works fine if homogra is the only include in the program.cpp.
I notice something strange. If I change the lines and I write before,in the #include lines, #include "segmentator.h" and then #include "homogra.h", then the compiler, with the same line for compiling :
g++ -o def program.cpp homogra.o segmentator.o `pkg-config --cflags opencv` `pkg-config --libs opencv`
is only recognising this time segmentator and not homogra. It is maybe a little difficult to understand, I tried to explained it as better as possible.
Any help!?
Many thanks in advance.
Here is homogra.h:
using namespace cv;
using namespace std;
#ifndef _NAMES_H
#define _NAMES_H
class homogra {
public:
Mat matCalculation( Mat img, Mat img2);
void printMatrix(Mat matrix);
};
#endif
In homogra.cpp I have all the tipical includes and homogra.h:
#include <stdio.h>
#include <stdlib.h>
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <iostream>
#include <sstream>
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include "homogra.h"
And then the functions explained.
Object 2 is segmentator.h
using namespace cv;
using namespace std;
#ifndef _NAMES_H
#define _NAMES_H
class segmentator {
public:
void search(Mat img,vector<std::vector<cv::Point> >& contours);
void similar(vector<std::vector<cv::Point> >& contours,vector<std::vector<cv::Point> >& contours2,vector<int>& idx);
vector<Mat> separate(Mat img,Mat img2,vector<std::vector<cv::Point> >& contours,vector<std::vector<cv::Point> >& contours2,vector<int> idx);
};
#endif
And in segmentator.cpp I have again all the same includes, except homogra.h and instead of this one I have segmentator.h.
Program.cpp is image_reg.cpp:
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <sstream>
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/calib3d/calib3d.hpp"
#include <opencv2/core/core.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/highgui/highgui.hpp>
#include "homogra.h"
#include "segmentator.h"
using namespace cv;
using namespace std;
int main(int argc, char ** argv )
{ //Here is the code where I try to invoque two instances of homogra and segmentator.
}
If I let homogra.h as the first to be read in the includes list of image_reg.cpp then only homogra.h is recognised, if I let at the first position segmentator, then only segmentator.h instances would be created and homogra. h would not be recognised.
Thanks
Your include header guards are wrong. They should be unique, using the name of the source file, rather than just _NAMES_H.
So in homogra.h you should have this:
#ifndef HOMOGRA_H
#define HOMOGRA_H
...
#endif
...and in segmentator.h, you should have this
#ifndef SEGMENTATOR_H
#define SEGMENTATOR_H
...
#endif
Also, it's really bad practice to have a using namespace xxx; in a header file. You make it very difficult for your headers to coexist with others.
As Jonathan Wakely points out, beginning symbols with underscores is not a great idea, either.