一、运动物体轮廓椭圆拟合及中心

1 #include "opencv2/opencv.hpp" 2 #include
     
       3 using namespace std; 4 using namespace cv; 5  6 Mat MoveDetect(Mat frame1, Mat frame2) 7 { 8     Mat result = frame2.clone(); 9     Mat gray1, gray2;10     cvtColor(frame1, gray1, CV_BGR2GRAY);11     cvtColor(frame2, gray2, CV_BGR2GRAY);12 13     Mat diff;14     absdiff(gray1, gray2, diff);15     imshow("absdiss", diff);16     threshold(diff, diff, 45, 255, CV_THRESH_BINARY);17     imshow("threshold", diff);18  19     Mat element = getStructuringElement(MORPH_RECT, Size(3, 3));20     Mat element2 = getStructuringElement(MORPH_RECT, Size(25, 25));21     erode(diff, diff, element);22     imshow("erode", diff);23  24     dilate(diff, diff, element2);25     imshow("dilate", diff);26 27     vector
      
       
        > contours;28     vector
        
          hierarcy;29     //画椭圆及中心30     findContours(diff, contours, hierarcy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_NONE);31     cout<<"num="<
         
          <
          
            box(contours.size());33 for(int i=0; i
           
            >frame;54 if(frame.empty())55 break;56 else{ 57 count++;58 if(count==1)59 background = frame.clone(); //提取第一帧为背景帧60 imshow("video", frame);61 result = MoveDetect(background, frame);62 imshow("result", result);63 if(waitKey(50)==27)64 break;65 }66 }67 cap.release(); 68 }
           
          
         
        
       
      
     

和上一篇文章代码的不同点在30-38行，天台行人视频适合用背景减法处理，自行车视频适合帧差法处理

二、滤波方法去除噪声

 上篇文章中使用腐蚀膨胀消除噪声，这次使用滤波方法去除噪声

中值滤波

　　//二值化后使用中值滤波+膨胀 　　Mat element = getStructuringElement(MORPH_RECT, Size(11, 11));    medianBlur(diff, diff, 5);//中值滤波    imshow("medianBlur", diff);    dilate(diff, diff, element);    imshow("dilate", diff);

均值滤波

#include "opencv2/opencv.hpp"#include
     
      using namespace std;using namespace cv;//int to string helper functionstring intToString(int number){    stringstream ss;    ss << number;    return ss.str();}Mat MoveDetect(Mat background, Mat img){    Mat result = img.clone();    Mat gray1, gray2;    cvtColor(background, gray1, CV_BGR2GRAY);    cvtColor(img, gray2, CV_BGR2GRAY);    Mat diff;    absdiff(gray1, gray2, diff);    threshold(diff, diff, 20, 255, CV_THRESH_BINARY);    imshow("threshold", diff);    blur(diff, diff, Size(10, 10));//均值滤波    imshow("blur", diff);    vector
      
       
        > contours;      vector
        
          hierarcy;    findContours(diff, contours, hierarcy, CV_RETR_EXTERNAL, CHAIN_APPROX_NONE); //查找轮廓    vector
         
           boundRect(contours.size()); //定义外接矩形集合    //drawContours(img2, contours, -1, Scalar(0, 0, 255), 1, 8);  //绘制轮廓    int x0=0, y0=0, w0=0, h0=0;    for(int i=0; i
          
           >frame; if(frame.empty()) break; else{ count++; if(count==1) background = frame.clone(); //提取第一帧为背景帧 imshow("video", frame); result = MoveDetect(background, frame); imshow("result", result); if(waitKey(50)==27) break; } } cap.release(); }
          
         
        
       
      
     

三、轮廓筛选去除噪声(效果挺好的)

//其余代码相同    int x0=0, y0=0, w0=0, h0=0;    for(int i=0; i
     
      30 && h0>30)            rectangle(result, Point(x0, y0), Point(x0+w0, y0+h0), Scalar(0, 255, 0), 2, 8); //绘制第i个外接矩形    }
     

四、运动轨迹绘制

#include "opencv2/opencv.hpp"#include
     
      using namespace std;using namespace cv;Point center;Point fre_center;//存储前一帧中心坐标int num=0;vector
      
        points;Mat MoveDetect(Mat background, Mat img){    Mat result = img.clone();    Mat gray1, gray2;    cvtColor(background, gray1, CV_BGR2GRAY);    cvtColor(img, gray2, CV_BGR2GRAY);    Mat diff;    absdiff(gray1, gray2, diff);    imshow("absdiss", diff);    threshold(diff, diff, 45, 255, CV_THRESH_BINARY);    imshow("threshold", diff);     Mat element = getStructuringElement(MORPH_RECT, Size(1, 1));    Mat element2 = getStructuringElement(MORPH_RECT, Size(9, 9));    erode(diff, diff, element);    imshow("erode", diff);    dilate(diff, diff, element2);    imshow("dilate", diff);    vector
       
        
         > contours;      vector
         
           hierarcy;    findContours(diff, contours, hierarcy, CV_RETR_EXTERNAL, CHAIN_APPROX_NONE); //查找轮廓    vector
          
            boundRect(contours.size()); //定义外接矩形集合 //drawContours(img2, contours, -1, Scalar(0, 0, 255), 1, 8); //绘制轮廓 vector
           
             box(contours.size()); int x0=0, y0=0, w0=0, h0=0; for(int i=0; i
            
             30 && h0>30)//筛选长宽大于30的轮廓 { num++; //rectangle(result, Point(x0, y0), Point(x0+w0, y0+h0), Scalar(0, 255, 0), 2, 8); //绘制第i个外接矩形 box[i] = fitEllipse(Mat(contours[i])); ellipse(result, box[i], Scalar(255, 0, 0), 2, 8); //椭圆轮廓 circle(result, box[i].center, 3, Scalar(0, 0, 255), -1, 8); //画中心 center = box[i].center;//当前帧的中心坐标 points.push_back(center);//中心塞进points向量集 if(num !=1) { //line(result, fre_center, center, Scalar(255, 0, 0), 2, 8); for(int j=0; j
             
              >frame; if(!frame.empty()) { count++; if(count==1) background = frame.clone(); //提取第一帧为背景帧 imshow("video", frame); result = MoveDetect(background, frame); imshow("result", result); if(waitKey(30)==27) break; } else break; } cap.release(); }
             
            
           
          
         
        
       
      
     

五、车辆数量检测

1.帧差法检测运动目标

2.预处理：a.转灰度图，绝对值做差　　b.二值化，腐蚀，中值滤波，膨胀　　c.查找轮廓，筛选轮廓，绘制外接矩形，计数，输出

1 #include "opencv2/opencv.hpp" 2 #include
     
       3 using namespace std; 4 using namespace cv; 5  6 int CarNum = 0; 7 //int to string helper function 8 string intToString(int number) 9 {10     //this function has a number input and string output11     stringstream ss;12     ss << number;13     return ss.str();14 }15 16 Mat MoveDetect(Mat frame1, Mat frame2) {17     Mat result = frame2.clone();18     Mat gray1, gray2;19     cvtColor(frame1, gray1, CV_BGR2GRAY);20     cvtColor(frame2, gray2, CV_BGR2GRAY);21 22     Mat diff;23     absdiff(gray1, gray2, diff);24     //imshow("absdiss", diff);25     threshold(diff, diff, 25, 255, CV_THRESH_BINARY);26     imshow("threshold", diff);27 28     Mat element = getStructuringElement(MORPH_RECT, Size(3, 3));29     Mat element2 = getStructuringElement(MORPH_RECT, Size(19, 19));30     erode(diff, diff, element);31     //imshow("erode", dst);32     medianBlur(diff, diff, 3);33     imshow("medianBlur", diff);34     dilate(diff, diff, element2);35     imshow("dilate", diff);36 37     vector
      
       
        > contours;38     vector
        
          hierarcy;39     findContours(diff, contours, hierarcy, CV_RETR_EXTERNAL, CV_CHAIN_APPROX_SIMPLE, Point(0, 0));//查找轮廓40     vector
         
          
           >contours_poly(contours.size());41 vector
           
             boundRect(contours.size()); //定义外接矩形集合42 //drawContours(img2, contours, -1, Scalar(0, 0, 255), 1, 8); //绘制轮廓43 int x0 = 0, y0 = 0, w0 = 0, h0 = 0;44 for (int i = 0; i
            
             55 && boundRect[i].width<180 && boundRect[i].height>55 && boundRect[i].height<180) { //轮廓筛选49 x0 = boundRect[i].x;50 y0 = boundRect[i].y;51 w0 = boundRect[i].width;52 h0 = boundRect[i].height;53 54 rectangle(result, Point(x0, y0), Point(x0 + w0, y0 + h0), Scalar(0, 255, 0), 2, 8, 0);55 if ((y0 + h0 / 2 + 1) >= 138 && (y0 + h0 / 2 - 1) <= 142) { //经过这条线（区间），车辆数量+156 CarNum++;57 }58 }59 line(result, Point(0, 140), Point(568, 140), Scalar(0, 0, 255), 1, 8);//画红线60 Point org(0, 35);61 putText(result, "CarNum=" + intToString(CarNum), org, CV_FONT_HERSHEY_SIMPLEX, 0.8f, Scalar(0, 255, 0), 2);62 }63 return result;64 }65 66 void main()67 {68 VideoCapture cap("E://2.avi");69 if (!cap.isOpened()) //检查打开是否成功70 return;71 Mat frame;72 Mat tmp;73 Mat result;74 int count = 0;75 while (1)76 {77 cap >> frame;78 if(frame.empty())//检查视频是否结束79 break;80 else{81 count++;82 if (count == 1) 83 result = MoveDetect(frame, frame);84 else result = MoveDetect(tmp, frame);85 imshow("video", frame);86 imshow("result", result);87 tmp = frame.clone();88 if (waitKey(20) == 27) 89 break;90 }91 }92 cap.release();93 }