contour.c

opencv图像处理讲义

/**************************************************
 * 轮廓检测
 * 主要函数：
 *      cvFindContours
 *      cvDrawContours
 **************************************************/

/***********************************************************************
 * OpenCV example
 * Copyright (C) 2006  Shiqi Yu
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 ***********************************************************************/
#include "cv.h"
#include "cxcore.h"
#include "highgui.h"

int main( int argc, char** argv )
{
  //声明IplImage指针
  IplImage* pImg = NULL; 
  IplImage* pContourImg = NULL;


  CvMemStorage * storage = cvCreateMemStorage(0);
  CvSeq * contour = 0;
  int mode = CV_RETR_EXTERNAL;

  if( argc == 3)
      if(strcmp(argv[2], "all") == 0)
	mode = CV_RETR_CCOMP; //内外轮廓都检测
      

  //创建窗口
  cvNamedWindow("src", 1);
  cvNamedWindow("contour",1);


  //载入图像，强制转化为Gray
  if( argc >= 2 && 
      (pImg = cvLoadImage( argv[1], 0)) != 0 )
    {

      cvShowImage( "src", pImg );

      //为轮廓显示图像申请空间
      //3通道图像，以便用彩色显示
      pContourImg = cvCreateImage(cvGetSize(pImg),
					  IPL_DEPTH_8U,
					  3);
      //copy source image and convert it to BGR image
      cvCvtColor(pImg, pContourImg, CV_GRAY2BGR);


      //查找contour
      cvFindContours( pImg, storage, &contour, sizeof(CvContour), 
		  mode, CV_CHAIN_APPROX_SIMPLE);

    }
  else
    {
      //销毁窗口
      cvDestroyWindow( "src" );
      cvDestroyWindow( "contour" );
      cvReleaseMemStorage(&storage);

      return -1;
    }




  //将轮廓画出    
  cvDrawContours(pContourImg, contour, 
		 CV_RGB(0,0,255), CV_RGB(255, 0, 0), 
		 2, 2, 8);
  //显示图像
  cvShowImage( "contour", pContourImg );

  cvWaitKey(0);


  //销毁窗口
  cvDestroyWindow( "src" );
  cvDestroyWindow( "contour" );
  //释放图像
  cvReleaseImage( &pImg ); 
  cvReleaseImage( &pContourImg ); 

  cvReleaseMemStorage(&storage);

  return 0;
}