cant get opencv to work

arkara · 2010-06-30 12:11:22

Ok, i did a

pacman -S opencv

and got a test code from the net:

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

// A Simple Camera Capture Framework
int main() {

  CvCapture* capture = cvCaptureFromCAM( CV_CAP_ANY );
  if( !capture ) {
    fprintf( stderr, "ERROR: capture is NULL \n" );
    getchar();
    return -1;
  }

  // Create a window in which the captured images will be presented
  cvNamedWindow( "mywindow", CV_WINDOW_AUTOSIZE );

  // Show the image captured from the camera in the window and repeat
  while( 1 ) {
    // Get one frame
    IplImage* frame = cvQueryFrame( capture );
    if( !frame ) {
      fprintf( stderr, "ERROR: frame is null...\n" );
      getchar();
      break;
    }

    cvShowImage( "mywindow", frame );
    // Do not release the frame!

    //If ESC key pressed, Key=0x10001B under OpenCV 0.9.7(linux version),
    //remove higher bits using AND operator
    if( (cvWaitKey(10) & 255) == 27 ) break;
  }

  // Release the capture device housekeeping
  cvReleaseCapture( &capture );
  cvDestroyWindow( "mywindow" );
  return 0;
}

but get the following message

aris@arch:~$ gcc test.c
test.c:1:16: fatal error: cv.h: No such file or directory
compilation terminated.

i think i have to link the files but -lopencv does not work. Any suggestions?

bharani · 2010-06-30 12:35:52

gcc test.c `pkg-config --libs --cflags opencv`

Note that ` is not single quotes.

You could also use this instead.

 gcc test.c  -I/usr/include/opencv  -lml -lcvaux -lhighgui -lcv -lcxcore

Last edited by bharani (2010-06-30 12:40:22)

arkara · 2010-06-30 12:50:37

thx man it worked.

Now for the arcane knowledge part:
-i(capital) specifies the include dir
and then u link each lib by it's own?

for the first case?
what is the pkg-config?

thanks again

for the first suggestion i get

aris@arch:~$ gcc test.c "pkg-config --libs --cflags opencv"
gcc: pkg-config --libs --cflags opencv: No such file or directory

Last edited by arkara (2010-06-30 13:01:11)

bharani · 2010-06-30 13:46:39

arkara wrote:

for the first suggestion i get

aris@arch:~$ gcc test.c "pkg-config --libs --cflags opencv"
gcc: pkg-config --libs --cflags opencv: No such file or directory

` symbol is grave accent. Not double quotes.(Below ~ symbol).

mpetersen3 · 2012-01-29 16:56:00

I am trying some similar code, I did pacman -S opencv, and then I am trying to compile a hello world in cpp named helloOcv.cxx (I had left it as cxx from when I was going to use cmake). I try entering:
g++ -I /usr/include/opencv/ -lcv -lhighgui

unfortunately I get:

/usr/bin/ld: cannot find -lcv
/usr/bin/ld: cannot find -lhighgui
collect2: ld returned 1 exit status

The opencv file is in usr/include/opencv and I can see the .h files located there. Any idea why this is not referencing?

Edit: Using gcc ./helloOcv.c -I/usr/include/opencv -lcv -lhighgui gives the same response, though if I change a function call, it points me to the source code, i suspect this is failing to link the OpenCV binaries

Last edited by mpetersen3 (2012-01-29 17:15:16)

Cdh · 2012-01-29 21:47:30

That's exactly why there is pkgconfig I believe: Those linker flags seem to be assigned very randomly depending on the version or the distribution.

On archlinux and opencv from repository you can only use those:

 ~ % pkg-config --libs --cflags opencv 
-I/usr/include/opencv  -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_ml -lopencv_video -lopencv_features2d -lopencv_calib3d -lopencv_objdetect -lopencv_contrib -lopencv_legacy -lopencv_flann

(or if you don't care and it's not seriously packaged software, simply all of them)

Last edited by Cdh (2012-01-29 21:48:22)

Arch Linux

#1 2010-06-30 12:11:22

cant get opencv to work

#2 2010-06-30 12:35:52

Re: cant get opencv to work

#3 2010-06-30 12:50:37

Re: cant get opencv to work

#4 2010-06-30 13:46:39

Re: cant get opencv to work

#5 2012-01-29 16:56:00

Re: cant get opencv to work

#6 2012-01-29 21:47:30

Re: cant get opencv to work

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