cvFitEllipse2

OpenCVサンプルコード　楕円のフィッティング cvFitEllipse2
#include <stdio.h>
#include <cxcore.h>
#include <cv.h>
#include <highgui.h>

int
main (int argc, char **argv)
{
  IplImage *src_img = 0, *dst_img;
  IplImage *src_img_gray = 0;
  IplImage *tmp_img;
  CvMemStorage *storage = cvCreateMemStorage (0);
  CvSeq *contours = 0;
  CvBox2D ellipse;
  CvTreeNodeIterator it;
  CvPoint2D32f pt[4];
 
  src_img = cvLoadImage ("2ti.GIF",1);
  if (src_img == 0){
	  printf("erro");
    return -1;}
 
  src_img_gray = cvCreateImage (cvGetSize (src_img), IPL_DEPTH_8U, 1);
  cvCvtColor (src_img, src_img_gray, CV_BGR2GRAY);
  tmp_img = cvCreateImage (cvGetSize (src_img), IPL_DEPTH_8U, 1);
  dst_img = cvCloneImage (src_img);
 
 
  // (2)二値化と輪郭の検出
  cvThreshold (src_img_gray, tmp_img, 95, 255, CV_THRESH_BINARY);
  cvFindContours (tmp_img, storage, &contours, sizeof (CvContour),
                  CV_RETR_TREE, CV_CHAIN_APPROX_SIMPLE, cvPoint (0, 0));
 
  // (3)ツリーノードイテレータの初期化
  cvInitTreeNodeIterator (&it, contours, 3);
  while ((contours = (CvSeq *) cvNextTreeNode (&it)) != NULL) {
    if (contours->total > 6) {
      // (4)楕円のフィッティング
      ellipse = cvFitEllipse2 (contours);
      ellipse.angle = 90.0 - ellipse.angle;
      printf("w:%f,h:%f\n",ellipse.size.width,ellipse.size.height);
      // (5)輪郭，楕円，包含矩形の描画
      cvDrawContours (dst_img, contours, CV_RGB (255, 0, 0), CV_RGB (255, 0, 0), 0, 1, CV_AA, cvPoint (0, 0));
      cvEllipseBox (dst_img, ellipse, CV_RGB (0, 0, 255), 2);
      cvBoxPoints (ellipse, pt);
      cvLine (dst_img, cvPointFrom32f (pt[0]), cvPointFrom32f (pt[1]), CV_RGB (0, 255, 0));
      cvLine (dst_img, cvPointFrom32f (pt[1]), cvPointFrom32f (pt[2]), CV_RGB (0, 255, 0));
      cvLine (dst_img, cvPointFrom32f (pt[2]), cvPointFrom32f (pt[3]), CV_RGB (0, 255, 0));
      cvLine (dst_img, cvPointFrom32f (pt[3]), cvPointFrom32f (pt[0]), CV_RGB (0, 255, 0));
    }
  }
 
  // (6)画像の表示
  cvNamedWindow ("Fitting", CV_WINDOW_AUTOSIZE);
  cvShowImage ("Fitting", dst_img);
  cvWaitKey (0);
 
  cvDestroyWindow ("Fitting");
  cvReleaseImage (&src_img);
  cvReleaseImage (&dst_img);
  cvReleaseImage (&src_img_gray);
  cvReleaseImage (&tmp_img);
  cvReleaseMemStorage (&storage);
 
  return 0;
}