/*
  Resize an image with a border (for display of vanishing line).
  J.K. Johnstone
 */

#include <cv.h>      // these two OpenCV libraries should be included 
#include <highgui.h> // in any OpenCV program
#include <iostream>
using namespace std;

IplImage *srcImg;   // original image (left untouched)
IplImage *editImg;  // image to be edited, in a larger window

void mouse (int event, int x, int y, int flags, void *param)
{
  switch (event) {
  case CV_EVENT_LBUTTONDOWN: 
    cvCircle (editImg, cvPoint(x,y), 2, // add red point at mouse location
	      CV_RGB(255,0,0), -1); 
    cvShowImage ("mousy", editImg);     // and redraw to show it
    break;
  }
}

int main (int argc, char **argv)
{
  if (argc != 2) 
    { cout << "Need an image parameter (jpg or ppm/pgm)" << endl; exit(-1); }
  srcImg = cvLoadImage (argv[1]);

  // copy image into a larger window with border of size 300 around each edge
  editImg = cvCreateImage (cvSize(srcImg->width + 600, srcImg->height + 600), 
	                     srcImg->depth, srcImg->nChannels);
  cvSetImageROI (editImg, cvRect (300, 300, srcImg->width, srcImg->height)); 
  cvResize (srcImg, editImg); // copy image over to subrectangle within larger image 
                              // (no rescaling necessary, but translation)
  cvResetImageROI (editImg);  // reset region of interest to entire image

  cvNamedWindow ("mousy", 1);
  cvSetMouseCallback ("mousy", mouse, 0);
  int done=0;
  while (!done)
    {
      cvShowImage   ("mousy", editImg); // 1st parameter is window
      int c = cvWaitKey(0);  // we now care what the keystroke is
      switch (int(c)) 
	{
	case 'c':  cvCopy (srcImg, editImg); break; // clear
	case 10:   done=1; break;                   // linefeed
	}
    }
  cvDestroyWindow("foo");
  cvReleaseImage (&srcImg);
  cvReleaseImage (&editImg);
  return 0;
}