Question

I am trying to write this simple image modifier program in c++ with opencv on netbeans. I am using ubuntu 10.04. Everytime I try to run or compile it, it returns the below errors. I have opencv configured in the linker and the additional tools. What is going wrong?

include stdlib.h  
include stdio.h  
include math.h  
include cv.h  
include highgui.h  
int main(int argc, char *argv[])  
{  
  IplImage* img = 0;  
  int height,width,step,channels;  
  uchar *data;  
  int i,j,k;  
  if(argc<2){  
    printf("Usage: main <image-file-name>\n\7");  
    exit(0);  
  }  
  // load an image  
  img=cvLoadImage(argv[1]);  
  if(!img){  
    printf("Could not load image file: %s\n",argv[1]);  
    exit(0);  
  }  
  // get the image data  
  height    = img->height;  
  width     = img->width;  
  step      = img->widthStep;  
  channels  = img->nChannels;  
  data      = (uchar *)img->imageData;  
  printf("Processing a %dx%d image with %d channels\n",height,width,channels);  
  // create a window  
  cvNamedWindow("mainWin", CV_WINDOW_AUTOSIZE);  
  cvMoveWindow("mainWin", 100, 100);  
  // invert the image  
  for(i=0;i<height;i++) for(j=0;j<width;j++) for(k=0;k<channels;k++)  
    data[i*step+j*channels+k]=255-data[i*step+j*channels+k];  
  // show the image  
  cvShowImage("mainWin", img );  
  // wait for a key  
  cvWaitKey(0);  
  // release the image  
  cvReleaseImage(&img );  
  return 0;  
}  

"/usr/bin/make" -f nbproject/Makefile-Debug.mk QMAKE= SUBPROJECTS= .build-conf  
make[1]: Entering directory `/home/kevin/NetBeansProjects/CppApplication_4'  
"/usr/bin/make"  -f nbproject/Makefile-Debug.mk dist/Debug/GNU-Linux-x86/cppapplication_4  
make[2]: Entering directory `/home/kevin/NetBeansProjects/CppApplication_4'  
mkdir -p build/Debug/GNU-Linux-x86  
rm -f build/Debug/GNU-Linux-x86/main.o.d  
g++    -c -g -MMD -MP -MF build/Debug/GNU-Linux-x86/main.o.d -o build/Debug/GNU-Linux-x86/  main.o main.cpp  
main.cpp:4:16: warning: cv.h: No such file or directory  
main.cpp:5:21: warning: highgui.h: No such file or directory  
main.cpp: In function ‘int main(int, char**)’:  
main.cpp:10: error: ‘IplImage’ was not declared in this scope  
main.cpp:10: error: ‘img’ was not declared in this scope  
main.cpp:12: error: ‘uchar’ was not declared in this scope  
main.cpp:12: error: ‘data’ was not declared in this scope  
main.cpp:21: error: ‘cvLoadImage’ was not declared in this scope  
main.cpp:32: error: expected primary-expression before ‘)’ token  
main.cpp:32: error: expected ‘;’ before ‘img’  
main.cpp:36: error: ‘CV_WINDOW_AUTOSIZE’ was not declared in this scope  
main.cpp:36: error: ‘cvNamedWindow’ was not declared in this scope  
main.cpp:37: error: ‘cvMoveWindow’ was not declared in this scope  
main.cpp:44: error: ‘cvShowImage’ was not declared in this scope  
main.cpp:47: error: ‘cvWaitKey’ was not declared in this scope  
main.cpp:50: error: ‘cvReleaseImage’ was not declared in this scope  
make[2]: *** [build/Debug/GNU-Linux-x86/main.o] Error 1  
make[1]: *** [.build-conf] Error 2  
make: *** [.build-impl] Error 2  
make[2]: Leaving directory `/home/kevin/NetBeansProjects/CppApplication_4'  
make[1]: Leaving directory `/home/kevin/NetBeansProjects/CppApplication_4'  

BUILD FAILED (exit value 2, total time: 115ms)  

EDIT:
Sorry for the massive jumble

Answer 1

Alright mister, this is your compilation line right here:

g++    -c -g -MMD -MP -MF build/Debug/GNU-Linux-x86/main.o.d -o build/Debug/GNU-Linux-x86/  main.o main.cpp

When you include headers using <>:

#include <cv.h>  
#include <highgui.h>  

the compiler will search those files on the default include path, which is usually: /usr/include

So, knowing that opencv doesn’t install its developments files on this directory, I must suggest you to find them. IF opencv is correctly installed on the system, the command pkg-config --cflags opencv is going to tell you where they are. Go ahead, try it. You could also execute pkg-config --libs opencv to find the libraries that you must add to the compilation.

To summarize everything, if you open up a terminal and cd to the directory where your source code is, the command below might compile your project IF you have opencv correctly installed.

g++ -c -g -MMD -MP -MF build/Debug/GNU-Linux-x86/main.o.d -o build/Debug/GNU-Linux-x86/  main.o main.cpp `pkg-config --cflags opencv` `pkg-config --libs opencv`

EDIT:

You know what? I just paste some code (opencv/camera) here (let’s call it funcam.cpp). You can use it to test if OpenCV is installed and compiles stuff on your system. You can compile it with:

g++ funcam.cpp -o funcam `pkg-config --cflags opencv` `pkg-config --libs opencv`

If it works, you must figure out how to configure Netbeans. If it doesn’t, you need to properly install OpenCV.