OpenCV读视频文件和运动问题检测

下面这个程序 来自于仕琪的讲稿 《使用OpenCV进行图像处理》]中的例程：

cvRunningAvg

　　opencv中的函数，用来更新移动平均。用法：

　　void cvRunningAvg(const CvArr * image,

　　CvArr* acc,

　　double alpha,

　　const CvArr* mask=NULL)

　　image:输入图像，1或3通道，8比特或32比特的float型

　　acc:累加器，和image一样大小

　　alpha：更新时，image所占的权重

　　mask：操作符掩码

　　if mask(x,y)!= 0 (1-alpha)*acc(x,y)+alpha*image(x,y) =>acc(x,y)

#if 0#include <stdio.h>#include <cv.h>#include <cxcore.h>#include <highgui.h>#pragma comment(lib, "cv.lib")#pragma comment(lib, "cxcore.lib")#pragma comment(lib, "highgui.lib")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( !(pCapture = cvCaptureFromAVI(".\\test.avi"))){//pCapture = cvCaptureFromCAM(-1))fprintf(stderr, "Can not open camera.\n");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(20) >= 0 ){break;}}}cvWaitKey();//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);cvReleaseCapture(&pCapture);return 0;}#else#include <cv.h>#include <highgui.h>#pragma comment(lib, "cv.lib")#pragma comment(lib, "cxcore.lib")#pragma comment(lib, "highgui.lib")int main( int argc, char** argv ){CvCapture* capture = NULL;IplImage *frame = NULL;IplImage  *frame_last = NULL;//存储上一帧IplImage  *m_out_image = NULL;IplImage* frame_gray = NULL;IplImage* frame_gray_last = NULL;IplImage* m_out_image_copy = NULL;int nFrmNum = 0;//capture = cvCaptureFromCAM(-1); capture = cvCaptureFromAVI(".\\test.avi");//创建窗口cvNamedWindow( "result", 1 );cvNamedWindow("差分");//逐帧读取视频while(frame = cvQueryFrame( capture )){nFrmNum++;//如果是第一帧，需要申请内存，并初始化if(nFrmNum == 1){frame_last = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U, frame->nChannels);cvCopy(frame,frame_last);}else{frame_gray = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U, 1);frame_gray_last = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U, 1);m_out_image = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U, 1);m_out_image_copy = cvCreateImage( cvSize(frame->width,frame->height),IPL_DEPTH_8U, 1 );cvCvtColor(frame,frame_gray,CV_RGB2GRAY);cvCvtColor(frame_last,frame_gray_last,CV_RGB2GRAY);cvAbsDiff(frame_gray,frame_gray_last,m_out_image);//cvThreshold(m_out_image,m_out_image,128, 255,CV_THRESH_BINARY);//将处理后的图像写出到第二个图像中if( m_out_image_copy->origin == IPL_ORIGIN_TL ){cvCopy( m_out_image, m_out_image_copy, 0 );}else{cvFlip( m_out_image, m_out_image_copy, 0 );}frame_last = cvCreateImage(cvSize(frame->width,frame->height),IPL_DEPTH_8U, frame->nChannels);cvCopy(frame,frame_last);cvShowImage("差分",m_out_image_copy);cvShowImage("result",frame);cvReleaseImage( &m_out_image_copy );cvReleaseImage( &frame_gray_last );cvReleaseImage( &frame_gray );if( cvWaitKey( 20 ) >= 0 ){break;}}}cvWaitKey();cvReleaseImage( &m_out_image );cvReleaseImage( &frame_last );cvReleaseImage( &frame );cvReleaseCapture( &capture );cvDestroyWindow("result");cvDestroyWindow("差分");return 0;}#endif