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


int main(int argc, char** argv){
  if( argc != 3 ) {
    printf( "Usage: mono colorimg monoimg\n" );
    exit( 0 );
  }
  IplImage *imgCol  = cvLoadImage( argv[1], -1);
  IplImage *imgMono = cvCreateImage( cvGetSize(imgCol), IPL_DEPTH_8U, 1);

  cvCvtColor( imgCol, imgMono, CV_RGB2GRAY );

  cvSaveImage( argv[2], imgMono );

  cvReleaseImage( &imgCol );
  cvReleaseImage( &imgMono );

}