单高斯背景建模opencv

/*******************单高斯背景建模v1.0************************* ************************2010.01.22****************************/ #include <highgui.h> #include <cv.h> #include <math.h> #include <stdio.h> #include <stdlib.h> int main(int argc, char **argv) { //新建窗口 cvNamedWindow("origin", CV_WINDOW_AUTOSIZE); cvNamedWindow("processing", CV_WINDOW_AUTOSIZE); double alpha = 0.05; //背景建模alpha值 double std_init = 20; //初始标准差 double var_init = std_init * std_init; //初始方差 double lamda = 2.5 * 1.2; //背景更新参数 //视频文件 CvCapture *capture = NULL; //读取视频文件 if (argc == 1) { //从摄像头读入 capture = cvCreateCameraCapture(0); } else if (argc == 2) { //从文件读入 capture = cvCreateFileCapture(argv[1]); } else { //读入错误 printf("input error\n"); return -1; } IplImage *frame = NULL; //原始图像 IplImage *frame_u = NULL; //期望图像 IplImage *frame_var = NULL; //方差图像 IplImage *frame_std = NULL; //标准差 CvScalar pixel = {0}; //像素原始值 CvScalar pixel_u = {0}; //像素期望 CvScalar pixel_var = {0}; //像素方差 CvScalar pixel_std = {0}; //像素标准差 //初始化frame_u, frame_var, frame_std frame = cvQueryFrame(capture); frame_u = cvCreateImage(cvSize(frame->width, frame->height), IPL_DEPTH_8U, 3); frame_var = cvCreateImage(cvSize(frame->width, frame->height), IPL_DEPTH_8U, 3); frame_std = cvCreateImage(cvSize(frame->width, frame->height), IPL_DEPTH_8U, 3); for (int y = 0; y < frame->height; ++y) { for (int x = 0; x < frame->width; ++x) { pixel = cvGet2D(frame, y, x); pixel_u.val[0] = pixel.val[0]; pixel_u.val[1] = pixel.val[1]; pixel_u.val[2] = pixel.val[2]; pixel_std.val[0] = std_init; pixel_std.val[1] = std_init; pixel_std.val[2] = std_init; pixel_var.val[0] = var_init; pixel_var.val[1] = var_init; pixel_var.val[2] = var_init; cvSet2D(frame_u, y, x, pixel_u); cvSet2D(frame_var, y, x, pixel_var); cvSet2D(frame_std, y, x, pixel_std); } } while (cvWaitKey(33) != 27) //按ESC键退出, 帧率33ms { frame = cvQueryFrame(capture); //视频结束退出 if (!frame) { break; } double t = (double)cvGetTickCount(); //单高斯背景更新 for (int y = 0; y < frame->height; ++y) { for (int x = 0; x < frame->width; ++x) { pixel = cvGet2D(frame, y, x); pixel_u = cvGet2D(frame_u, y, x); pixel_std = cvGet2D(frame_std, y, x); pixel_var = cvGet2D(frame_var, y, x); //|I-u| < lamda*std 时认为是背景, 进行更新 if (fabs(pixel.val[0] - pixel_u.val[0]) < lamda * pixel_std.val[0] && fabs(pixel.val[1] - pixel_u.val[1]) < lamda * pixel_std.val[1] && fabs(pixel.val[2] - pixel_u.val[2]) < lamda * pixel_std.val[2]) { //更新期望 u = (1-alpha)*u + alpha*I pixel_u.val[0] = (1 - alpha) * pixel_u.val[0] + alpha * pixel.val[0]; pixel_u.val[1] = (1 - alpha) * pixel_u.val[1] + alpha * pixel.val[1]; pixel_u.val[2] = (1 - alpha) * pixel_u.val[2] + alpha * pixel.val[2]; //更新方差 var = (1-alpha)*var + alpha*(I-u)^2 pixel_var.val[0] = (1 - alpha) * pixel_var.val[0] + (pixel.val[0] - pixel_u.val[0]) * (pixel.val[0] - pixel_u.val[0]); pixel_var.val[1] = (1 - alpha) * pixel_var.val[1] + (pixel.val[1] - pixel_u.val[1]) * (pixel.val[1] - pixel_u.val[1]); pixel_var.val[2] = (1 - alpha) * pixel_var.val[2] + (pixel.val[2] - pixel_u.val[2]) * (pixel.val[2] - pixel_u.val[2]); //更新标准差 pixel_std.val[0] = sqrt(pixel_var.val[0]); pixel_std.val[1] = sqrt(pixel_var.val[1]); pixel_std.val[2] = sqrt(pixel_var.val[2]); //写入矩阵 cvSet2D(frame_u, y, x, pixel_u); cvSet2D(frame_var, y, x, pixel_var); cvSet2D(frame_std, y, x, pixel_std); } } } t = (double)cvGetTickCount() - t; printf( "detection time = %gms\n", t/((double)cvGetTickFrequency()*1000.) ); //显示结果 cvShowImage("origin", frame); cvShowImage("processing", frame_u); cvShowImage("processing1", frame_std); cvShowImage("processing2", frame_var); } //释放内存 cvReleaseCapture(&capture); cvReleaseImage(&frame); cvReleaseImage(&frame_u); cvReleaseImage(&frame_var); cvReleaseImage(&frame_std); cvDestroyWindow("origin"); cvDestroyWindow("processing"); return 0; }