OpenCV鼠标绘制矩形和截取矩形区域图像

本文实例为大家分享了OpenCV鼠标绘制截取矩形区域图像的具体代码，供大家参考，具体内容如下

在opencv中利用鼠标绘制矩形，代码如下：

#include <cv.h>
#include <highgui.h>
#include <stdio.h>
#pragma comment( lib, "cv.lib" )
#pragma comment( lib, "cxcore.lib" )
#pragma comment( lib, "highgui.lib" )
IplImage* src = 0;
IplImage* dst = 0;
void 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(dst,src);
    sprintf(temp,"(%d,%d)",x,y);
    pre_pt = cvPoint(x,y);
    cvPutText(src,temp, pre_pt, &font, cvScalar(0,0, 0, 255));
    cvCircle( src, pre_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
    cvShowImage( "src", src );
    cvCopy(src,dst);
  }
  else if( event == CV_EVENT_MOUSEMOVE && !(flags & CV_EVENT_FLAG_LBUTTON))
  {
    cvCopy(dst,src);
    sprintf(temp,"(%d,%d)",x,y);
    cur_pt = cvPoint(x,y);
    cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
    cvShowImage( "src", src );
  }
  else if( event == CV_EVENT_MOUSEMOVE && (flags & CV_EVENT_FLAG_LBUTTON))
  {
    cvCopy(dst,src);
    sprintf(temp,"(%d,%d)",x,y);
    cur_pt = cvPoint(x,y);
    cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
    cvRectangle(src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );
    cvShowImage( "src", src );
  }
  else if( event == CV_EVENT_LBUTTONUP )
  {
    sprintf(temp,"(%d,%d)",x,y);
    cur_pt = cvPoint(x,y);
    cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));
    cvCircle( src, cur_pt, 3,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );
    cvRectangle( src, pre_pt, cur_pt, cvScalar(0,255,0,0), 1, 8, 0 );
    cvShowImage( "src", src );
    cvCopy(src,dst);
  }
}
int main()
{
  src=cvLoadImage("lena.jpg",1);
  dst=cvCloneImage(src);
  cvNamedWindow("src",1);
  cvSetMouseCallback( "src", on_mouse, 0 ); 

  cvShowImage("src",src);
  cvWaitKey(0);
  cvDestroyAllWindows();
  cvReleaseImage(&src);
  cvReleaseImage(&dst);
  return 0;

在opencv中利用鼠标绘制矩形并截取该矩形区域的图像

测试代码如下：

#include <cv.h>
#include <highgui.h>
#include <stdio.h>
#pragma comment( lib, "cv.lib" )
#pragma comment( lib, "cxcore.lib" )
#pragma comment( lib, "highgui.lib" )
IplImage* org = 0;
IplImage* img = 0;
IplImage* tmp = 0;
IplImage* dst = 0;
void 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);
    cvSaveImage("dst.jpg",dst);
  }
}
int main()
{
  org=cvLoadImage("lena.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;
}

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