opencv鼠标经过读取坐标以及划动画框

本代码copy自：

http://www.cnblogs.com/lidabo/p/3437587.html

#include <opencv2/opencv.hpp>#include <opencv2/core/core.hpp>  #include <opencv2/highgui/highgui.hpp>  #include <stdio.h>    using namespace cv;    cv::Mat org,dst,img,tmp;  //event:id of mouse click event;//x,y:mouse coordinate;;//flags: drag or keyboard id  void on_mouse(int event,int x,int y,int flags,void *ustc){      static Point pre_pt = Point(-1,-1);//pre coordinate;      static Point cur_pt = Point(-1,-1);//current coordinate;      char temp[16];      if (event == CV_EVENT_LBUTTONDOWN)//left click，draw a circle on the position      {          org.copyTo(img);        sprintf(temp,"(%d,%d)",x,y);          pre_pt = Point(x,y);          putText(img,temp,pre_pt,FONT_HERSHEY_SIMPLEX,0.5,Scalar(0,0,0,255),1,8);//show the coordinate          circle(img,pre_pt,2,Scalar(255,0,0,0),CV_FILLED,CV_AA,0);//draw a circle          imshow("img",img);      }      else if (event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))//mouse pass by without click      {          img.copyTo(tmp);          sprintf(temp,"(%d,%d)",x,y);          cur_pt = Point(x,y);          putText(tmp,temp,cur_pt,FONT_HERSHEY_SIMPLEX,0.5,Scalar(0,0,0,255));//real time show coordinate          imshow("img",tmp);      }      else if (event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))//left click and move mouse,draw a real time rectangle      {          img.copyTo(tmp);          sprintf(temp,"(%d,%d)",x,y);          cur_pt = Point(x,y);          putText(tmp,temp,cur_pt,FONT_HERSHEY_SIMPLEX,0.5,Scalar(0,0,0,255));          rectangle(tmp,pre_pt,cur_pt,Scalar(0,255,0,0),1,8,0);          imshow("img",tmp);      }      else if (event == CV_EVENT_LBUTTONUP)//release left click,draw a rectangle      {          org.copyTo(img);          sprintf(temp,"(%d,%d)",x,y);          cur_pt = Point(x,y);          putText(img,temp,cur_pt,FONT_HERSHEY_SIMPLEX,0.5,Scalar(0,0,0,255));          circle(img,pre_pt,2,Scalar(255,0,0,0),CV_FILLED,CV_AA,0);          rectangle(img,pre_pt,cur_pt,Scalar(0,255,0,0),1,8,0);        imshow("img",img);          img.copyTo(tmp);          //show the roi that cut by rectangle         int width = abs(pre_pt.x - cur_pt.x);          int height = abs(pre_pt.y - cur_pt.y);          if (width == 0 || height == 0)          {              printf("width == 0 || height == 0");              return;          }          dst = org(Rect(min(cur_pt.x,pre_pt.x),min(cur_pt.y,pre_pt.y),width,height));          namedWindow("dst");          imshow("dst",dst);          waitKey(0);      }  }  int main()  {      org = imread("/home/bot/Downloads/loading_state/data_0_1504602551362.jpg");      org.copyTo(img);      org.copyTo(tmp);      namedWindow("img");     setMouseCallback("img",on_mouse,0);//callback      imshow("img",img);      cv::waitKey(0);      return 0;}