#include "cv.h" #include "highgui.h" #include "stdlib.h" #include "malloc.h" #include "cxcore.h" #include "assert.h" #include <time.h> #include <math.h> #include <ctype.h> #include <stdio.h> #include <iostream> using namespace std; // various tracking parameters (in seconds) const double MHI_DURATION = 1; const double MAX_TIME_DELTA = 0.5; const double MIN_TIME_DELTA = 0.05; // number of cyclic frame buffer used for motion detection // (should, probably, depend on FPS) //用于运动检测的循环帧数 const int N = 4; // ring image buffer IplImage **buf = 0; int last = 0; // temporary images IplImage *mhi = 0; // MHI IplImage *orient = 0; // orientation IplImage *mask = 0; // valid orientation mask IplImage *segmask = 0; // motion segmentation map CvMemStorage* storage = 0; // temporary storage // parameters: // img - input video frame // dst - resultant motion picture // args - optional parameters void update_mhi(IplImage* img, IplImage* dst, int diff_threshold) { double timestamp = (double)clock() / CLOCKS_PER_SEC; // get current time in seconds CvSize size = cvSize(img->width, img->height); // get current frame size int i, idx1 = last, idx2; IplImage* silh; CvSeq* seq; CvRect comp_rect; double count; double angle; CvPoint center; double magnitude; CvScalar color; // allocate images at the beginning or 为图像分配初始空间 // reallocate them if the frame size is changed 当帧的大小改变时，重新分配内存空间 if (!mhi || mhi->width != size.width || mhi->height != size.height) { if (buf == 0) { buf = (IplImage**)malloc(N*sizeof(buf[0])); memset(buf, 0, N*sizeof(buf[0]));//把申请到的内存空间用0初始化 } for (i = 0; i < N; i++) { cvReleaseImage(&buf[i]); buf[i] = cvCreateImage(size, IPL_DEPTH_8U, 1); cvZero(buf[i]); } cvReleaseImage(&mhi); cvReleaseImage(&orient); cvReleaseImage(&segmask); cvReleaseImage(&mask); mhi = cvCreateImage(size, IPL_DEPTH_32F, 1); cvZero(mhi); // clear MHI at the beginning orient = cvCreateImage(size, IPL_DEPTH_32F, 1); segmask = cvCreateImage(size, IPL_DEPTH_32F, 1); mask = cvCreateImage(size, IPL_DEPTH_8U, 1); } cvCvtColor(img, buf[last], CV_BGR2GRAY); // convert frame to grayscale 转换为灰度图 idx2 = (last + 1) % N; // index of (last - (N-1))th frame last = idx2; silh = buf[idx2]; cvAbsDiff(buf[idx1], buf[idx2], silh); // get difference between frames相邻两帧之差 cvThreshold(silh, silh, diff_threshold, 1, CV_THRESH_BINARY); // and threshold it cvUpdateMotionHistory(silh, mhi, timestamp, MHI_DURATION); // update MHI // convert MHI to blue 8u image cvCvtScale(mhi, mask, 255. / MHI_DURATION, (MHI_DURATION - timestamp)*255. / MHI_DURATION); cvZero(dst); cvCvtPlaneToPix(mask, 0, 0, 0, dst); // calculate motion gradient orientation and valid orientation mask计算运动的梯度方向以及正确的方向掩码 cvCalcMotionGradient(mhi, mask, orient, MAX_TIME_DELTA, MIN_TIME_DELTA, 3); if (!storage) storage = cvCreateMemStorage(0); else cvClearMemStorage(storage); // segment motion: get sequence of motion components运动分割:获取运动组成成分的序列 // segmask is marked motion components map. It is not used further seq = cvSegmentMotion(mhi, segmask, storage, timestamp, MAX_TIME_DELTA); // iterate through the motion components,迭代运动的组成成分 // One more iteration (i == -1) corresponds to the whole image (global motion) for (i = -1; i < seq->total; i++) { if (i < 0) { // case of the whole image comp_rect = cvRect(0, 0, size.width, size.height); color = CV_RGB(255, 255, 255); magnitude = 100; } else { // i-th motion component comp_rect = ((CvConnectedComp*)cvGetSeqElem(seq, i))->rect; if (comp_rect.width + comp_rect.height < 100) // reject very small components continue; color = CV_RGB(255, 0, 0); magnitude = 30; } // select component ROI cvSetImageROI(silh, comp_rect); cvSetImageROI(mhi, comp_rect); cvSetImageROI(orient, comp_rect); cvSetImageROI(mask, comp_rect); // calculate orientation在选择区域内计算运动方向 angle = cvCalcGlobalOrientation(orient, mask, mhi, timestamp, MHI_DURATION); angle = 360.0 - angle; // adjust for images with top-left origin count = cvNorm(silh, 0, CV_L1, 0); // calculate number of points within silhouette ROI cvResetImageROI(mhi); cvResetImageROI(orient); cvResetImageROI(mask); cvResetImageROI(silh); // check for the case of little motion if (count < comp_rect.width*comp_rect.height * 0.05) continue; //// draw a clock with arrow indicating the direction画一个“钟表”指向运动的方向 //center = cvPoint((comp_rect.x + comp_rect.width / 2), // (comp_rect.y + comp_rect.height / 2)); //cvCircle(dst, center, cvRound(magnitude*1.2), color, 3, CV_AA, 0); //cvLine(dst, center, cvPoint(cvRound(center.x + magnitude*cos(angle*CV_PI / 180)), // cvRound(center.y - magnitude*sin(angle*CV_PI / 180))), color, 3, CV_AA, 0); } } int main(int argc, char** argv) { IplImage* motion = 0; CvCapture* capture = 0; capture = cvCaptureFromFile("E:Videos\daria_walk.avi"); if (capture) { cvNamedWindow("Motion", 1); for (;;) { IplImage* image; if (!cvGrabFrame(capture)) break; //Decodes and returns the grabbed video frame. //C++: bool VideoCapture::retrieve(Mat& image, int channel=0) // IplImage* cvRetrieveFrame(CvCapture* capture, int streamIdx=0 ) image = cvRetrieveFrame(capture); if (image) { if (!motion) { //Creates an image header and allocates the image data. //C: IplImage* cvCreateImage(CvSize size, int depth, int channels) motion = cvCreateImage(cvSize(image->width, image->height), 8, 3); //Clears the array. //C: void cvSetZero(CvArr* arr) cvZero(motion); motion->origin = image->origin; } } update_mhi(image, motion, 30); cvShowImage("Motion", motion); if (cvWaitKey(10) >= 0) break; } cvReleaseCapture(&capture); cvDestroyWindow("Motion"); } return 0; }