bkgrd.c

opencv图像处理讲义

/**************************************************
 * 背景建模，运动物体检测
 *      
 **************************************************/

/***********************************************************************
 * 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 <stdio.h>

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

int main( int argc, char** argv )
{
  //声明IplImage指针
  IplImage* pFrame = NULL; 
  IplImage* pFrImg = NULL;
  IplImage* pBkImg = NULL;

  CvMat* pFrameMat = NULL;
  CvMat* pFrMat = NULL;
  CvMat* pBkMat = NULL;
  
  CvCapture* pCapture = NULL;
  
  int nFrmNum = 0;

  //创建窗口
  cvNamedWindow("video", 1);
  cvNamedWindow("background",1);
  cvNamedWindow("foreground",1);
  //使窗口有序排列
  cvMoveWindow("video", 30, 0);
  cvMoveWindow("background", 360, 0);
  cvMoveWindow("foreground", 690, 0);



  if( argc != 2 )
    {
      fprintf(stderr, "Usage: bkgrd <video_file_name>\n");
      return -1;
    }

  //打开视频文件
  if( !(pCapture = cvCaptureFromFile(argv[1])))
    {
      fprintf(stderr, "Can not open video file %s\n", argv[1]);
      return -2;
    }
  
  //逐帧读取视频
  while(pFrame = cvQueryFrame( pCapture ))
    {
      nFrmNum++;
      
      //如果是第一帧，需要申请内存，并初始化
      if(nFrmNum == 1)
	{
	  pBkImg = cvCreateImage(cvSize(pFrame->width, pFrame->height),  IPL_DEPTH_8U,1);
	  pFrImg = cvCreateImage(cvSize(pFrame->width, pFrame->height),  IPL_DEPTH_8U,1);

	  pBkMat = cvCreateMat(pFrame->height, pFrame->width, CV_32FC1);
	  pFrMat = cvCreateMat(pFrame->height, pFrame->width, CV_32FC1);
	  pFrameMat = cvCreateMat(pFrame->height, pFrame->width, CV_32FC1);

	  //转化成单通道图像再处理
	  cvCvtColor(pFrame, pBkImg, CV_BGR2GRAY);
	  cvCvtColor(pFrame, pFrImg, CV_BGR2GRAY);

	  cvConvert(pFrImg, pFrameMat);
	  cvConvert(pFrImg, pFrMat);
	  cvConvert(pFrImg, pBkMat);
	}
      else
	{
	  cvCvtColor(pFrame, pFrImg, CV_BGR2GRAY);
	  cvConvert(pFrImg, pFrameMat);
	  //高斯滤波先，以平滑图像
	  //cvSmooth(pFrameMat, pFrameMat, CV_GAUSSIAN, 3, 0, 0);
	  
	  //当前帧跟背景图相减
	  cvAbsDiff(pFrameMat, pBkMat, pFrMat);

	  //二值化前景图
	  cvThreshold(pFrMat, pFrImg, 60, 255.0, CV_THRESH_BINARY);

	  //进行形态学滤波，去掉噪音  
	  //cvErode(pFrImg, pFrImg, 0, 1);
	  //cvDilate(pFrImg, pFrImg, 0, 1);

	  //更新背景
	  cvRunningAvg(pFrameMat, pBkMat, 0.003, 0);
	  //将背景转化为图像格式，用以显示
	  cvConvert(pBkMat, pBkImg);

	  //显示图像
	  cvShowImage("video", pFrame);
	  cvShowImage("background", pBkImg);
	  cvShowImage("foreground", pFrImg);

	  //如果有按键事件，则跳出循环
	  //此等待也为cvShowImage函数提供时间完成显示
	  //等待时间可以根据CPU速度调整
	  if( cvWaitKey(2) >= 0 )
	    break;


	}

    }

    


  //销毁窗口
  cvDestroyWindow("video");
  cvDestroyWindow("background");
  cvDestroyWindow("foreground");

  //释放图像和矩阵
  cvReleaseImage(&pFrImg);
  cvReleaseImage(&pBkImg);

  cvReleaseMat(&pFrameMat);
  cvReleaseMat(&pFrMat);
  cvReleaseMat(&pBkMat);

  return 0;
}