openCV实现鼠标响应裁剪图像

给定一幅图像，将其中的某一部分兴趣区域裁剪出来，这在PS中很好实现，但是使用openCV如何实现呢？因此本文主要介绍openCV使用鼠标响应来裁剪图像：
一、代码部分：

#include "stdafx.h"#include "cv.h" #include <highgui.h>  #include <stdio.h> IplImage* org = 0;  IplImage* img = 0;   IplImage* tmp = 0;   IplImage* dst = 0;  //The mouse cuts the image accordinglyvoid on_mouse( int event, int x, int y, int flags, void* ustc)  {      static CvPoint pre_pt = {-1,-1};      static CvPoint cur_pt = {-1,-1};      CvFont font;      cvInitFont(&font, CV_FONT_HERSHEY_SIMPLEX, 0.5, 0.5, 0, 1, CV_AA);      char temp[16];      if(event == CV_EVENT_LBUTTONDOWN)      {          cvCopy(org,img);          sprintf(temp,"(%d,%d)",x,y);          pre_pt = cvPoint(x,y);          cvPutText(img,temp, pre_pt, &font, cvScalar(0,0, 0, 255));          cvCircle( img, pre_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );          cvShowImage( "img", img );          cvCopy(img,tmp);      }      else if( event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))      {          cvCopy(tmp,img);          sprintf(temp,"(%d,%d)",x,y);          cur_pt = cvPoint(x,y);                cvPutText(img,temp, cur_pt, &font, cvScalar(0,0, 0, 255));          cvShowImage( "img", img );      }      else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))      {          cvCopy(tmp,img);          sprintf(temp,"(%d,%d)",x,y);          cur_pt = cvPoint(x,y);                cvPutText(img,temp, cur_pt, &font, cvScalar(0,0,0,255));          cvRectangle(img, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );          cvShowImage( "img", img );      }      else if(event == CV_EVENT_LBUTTONUP)      {          cvCopy(tmp,img);          sprintf(temp,"(%d,%d)",x,y);          cur_pt = cvPoint(x,y);                cvPutText(img,temp, cur_pt, &font, cvScalar(0,0, 0, 255));          cvCircle( img, cur_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );          cvRectangle( img, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );          cvShowImage( "img", img );          cvCopy(img,tmp);          int width=abs(pre_pt.x-cur_pt.x);          int height=abs(pre_pt.y-cur_pt.y);          if(width==0 || height==0)          {              cvDestroyWindow("dst");              return;          }          dst=cvCreateImage(cvSize(width,height),org->depth,org->nChannels);          CvRect rect;          if(pre_pt.x<cur_pt.x && pre_pt.y<cur_pt.y)          {              rect=cvRect(pre_pt.x,pre_pt.y,width,height);          }          else if(pre_pt.x>cur_pt.x && pre_pt.y<cur_pt.y)          {              rect=cvRect(cur_pt.x,pre_pt.y,width,height);          }          else if(pre_pt.x>cur_pt.x && pre_pt.y>cur_pt.y)          {              rect=cvRect(cur_pt.x,cur_pt.y,width,height);          }          else if(pre_pt.x<cur_pt.x && pre_pt.y>cur_pt.y)          {              rect=cvRect(pre_pt.x,cur_pt.y,width,height);          }          cvSetImageROI(org,rect);          cvCopy(org,dst);          cvResetImageROI(org);          cvDestroyWindow("dst");          cvNamedWindow("dst",1);          cvShowImage("dst",dst);          cvWaitKey(0);        cvSaveImage("..\\post_img\\71253.jpg",dst);      }  } int _tmain(int argc, _TCHAR* argv[]){    org=cvLoadImage("..\\image_norm\\71253.jpg",1);      img=cvCloneImage(org);      tmp=cvCloneImage(org);      cvNamedWindow("img",1);      cvSetMouseCallback( "img", on_mouse, 0);      cvShowImage("img",img);      cvWaitKey(0);       cvDestroyAllWindows();      cvReleaseImage(&org);      cvReleaseImage(&img);      cvReleaseImage(&tmp);      cvReleaseImage(&dst);      return 0;}

二、程序运行效果图：

将鼠标放在原图上的某一点，会显示相应点的位置坐标。至此，openCV使用鼠标响应实现图像裁剪已经实现。