1 #include

2 #include

3 #include //时间函数头

4 #include "opencv.hpp"

5

6 /**7 * A program to detect motion in front of an USB camera using OpenCV.8 **/

9

10 int main(int argc, char **argv) {11 int detectThreshold = 19; //运动检测预设值(时间)

12 if (argc >= 2) { //判断参数是否充足判断

13 detectThreshold = atoi(argv[1]);14 printf("=== Motion detection threshold has been set to: [%d] ===\n", detectThreshold);15 }16

17 /*init 摄影机*/

18 CvCapture* pCapture = cvCreateCameraCapture(0);19 if (NULL ==pCapture) {20 fprintf(stderr, "Can't initialize webcam!\n");21 return 1;22 }23 cvSetCaptureProperty(pCapture, CV_CAP_PROP_FRAME_WIDTH, 640);24 cvSetCaptureProperty(pCapture, CV_CAP_PROP_FRAME_HEIGHT, 480);25 cvSetCaptureProperty(pCapture, CV_CAP_PROP_BRIGHTNESS, 20);26 cvSetCaptureProperty(pCapture, CV_CAP_PROP_CONTRAST, 10);27

28 /*图像指针*/

29 IplImage *pFrameA = cvQueryFrame(pCapture); //从摄像头或者文件中抓取并返回一帧

30 IplImage *pFrameB = cvCreateImage(cvSize(pFrameA->width, pFrameA->height), pFrameA->depth, pFrameA->nChannels); //创建图像((矩形框大小)，颜色深度，通道)31 //就是直接把pFrameB这个图像复制给dst，不用给 pFrameDiff 特地开辟内存空间了

32 IplImage *pFrameDiff =cvCloneImage(pFrameB);33

34 int nDims = 256;35 float hRangesArr[] = {0, 255};36 float* hRanges =hRangesArr;37 /*直方图，表上数字图像中亮度分布的一种图，标绘了每个像素的亮度数(可以使用直方图对图像进行二值化，通过计算差异图像的直方图，可以知道这两附图有没有差异*/

38 IplImage *pGrayscaleImage =NULL;39 CvHistogram *pHist = cvCreateHist(1, &nDims, CV_HIST_ARRAY, &hRanges, 1);40 float fMaxValue = 0.0;41

42 time_t ts = 0; //用于记录当前时间戳和防止1次触发多次监测检测

43 while(true) {44 pFrameA = cvQueryFrame(pCapture); //从摄像头或者文件中抓取并返回一帧

45 if(!pFrameA){ //判断是否成功采集

46 fprintf(stdout,"Can't grab images!\n");47 break;48 }49 cvAbsDiff(pFrameB,pFrameA,pFrameDiff); //计算两幅图像的差异

50 cvCopy(pFrameA,pFrameB); //复制图像，第一个参数是源与第二目标51 //实现了8位深的灰度图像

52 pGrayscaleImage = cvCreateImage(cvGetSize(pFrameDiff),IPL_DEPTH_8U,1);53 //void cvCvtColor( const CvArr* src, CvArr* dst, int code );54 //src 输入的 8-bit,16-bit或 32-bit单倍精度浮点数影像。55 //dst 输出的8-bit, 16-bit或 32-bit单倍精度浮点数影像。56 //code 色彩空间转换的模式，该code来实现不同类型的颜色空间转换。比如CV_BGR2GRAY表示转换为灰度图，CV_BGR2HSV将图片从RGB空间转换为HSV空间。其中当code选用CV_BGR2GRAY时，dst需要是单通道图片。当code选用CV_BGR2HSV时，对于8位图，需要将RGB值归一化到0-1之间。这样得到HSV图中的H范围才是0-360，S和V的范围是0-1。

57 cvCvtColor(pFrameDiff, pGrayscaleImage, CV_BGR2GRAY);58 cvCalcHist(&pGrayscaleImage, pHist, 0, 0);59

60 fMaxValue = 0.0;61 //找到直方图中最大最小直方块，以及他们的位置，并保存到 fMaxValue 中

62 cvGetMinMaxHistValue(pHist, 0, &fMaxValue, 0, 0);63 //用于对直方图的比例缩放

64 cvConvertScale(pHist->bins, pHist->bins, (fMaxValue ? (255.0 / fMaxValue) : 0.0), 0);65 //检查是否有运动状态

66 double dRealtimeVal = cvGetReal1D(pHist->bins, 10);67 if (dRealtimeVal > detectThreshold) { //触发

68 time_t currentTimestamp =time(NULL);69 if (currentTimestamp - ts >= 1) { //对时间戳进行判断

70 ts =currentTimestamp;71 printf("Motion detected @ %s", ctime(&currentTimestamp));72 }73 }74 cvReleaseImage(&pGrayscaleImage); //释放内存

75 pGrayscaleImage =NULL;76

77 cvWaitKey(10); //等待n毫秒

78 }79 //停止捕获图像和释放资源

80 cvReleaseCapture(&pCapture);81 cvReleaseHist(&pHist);82 cvReleaseImage(&pFrameA);83 cvReleaseImage(&pFrameB);84 cvReleaseImage(&pFrameDiff);85

86 pCapture =NULL;87 pHist =NULL;88 pFrameA =NULL;89 pFrameB =NULL;90 pFrameDiff =NULL;91

92 return 0;93 }