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; 
} 

以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持呐喊教程。

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