OpenCV实现鼠标在图像上框选单目标和多目标

2020-01-26 13:25:36

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本文实例为大家分享了OpenCV实现鼠标框选并显示框选区域的具体代码，供大家参考，具体内容如下

鼠标在图像上框选目标：

1. 用到鼠标回调函数

2. 回调函数里面分三部分

(1)鼠标按下左键

(2)鼠标按下的同时移动左键

(3)鼠标左键弹起

3. 图像显示的刷新

单目标：

#include <cv.h>#include <highgui.h>#include <stdio.h> IplImage* src = 0; IplImage* tmp = 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);//初始化字体 char temp[16];  if( (event == CV_EVENT_LBUTTONDOWN)&&(flags) )//鼠标左键按下时 { sprintf(temp,"(%d,%d)",x,y);//格式化字符串 pre_pt = cvPoint(x,y);//获取当前点坐标值 cvPutText(src,temp, pre_pt, &font, cvScalar(0,0, 0, 255));//在图像是打印字符 cvCircle( src, pre_pt, 2,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );//在图像上画圆 cvShowImage( "src", src ); //cvCopy(src,tmp);//这句有没有，就是单目标和多目标的问题  } else if( (event == CV_EVENT_MOUSEMOVE) && (flags & CV_EVENT_LBUTTONDOWN)) {//鼠标移动并且鼠标左键按下 sprintf(temp,"(%d,%d)",x,y);//格式化字符串 cur_pt = cvPoint(x,y);//获取当前点坐标值  cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));//在图像是打印字符 cvRectangle(src, pre_pt, cur_pt, cvScalar(0,255,0,0), 2, 8, 0 );//在图像上画矩形 cvShowImage( "src", src ); cvCopy(tmp,src);//将img复制到临时图像tmp上，用于实时显示 } else if( event == CV_EVENT_LBUTTONUP ) {//鼠标左键弹起 sprintf(temp,"(%d,%d)",x,y);//字体格式化 cur_pt = cvPoint(x,y);//获取当前点坐标值  cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));//在图像是打印字符 cvCircle( src, cur_pt, 2,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );//在图像上画圆 cvRectangle( src, pre_pt, cur_pt, cvScalar(0,255,0,0), 2, 8, 0 );//在图像上画矩形 cvShowImage( "src", src ); }}int main(){ src=cvLoadImage("lena.jpg",1);//读入图像 tmp=cvCloneImage(src);//复制图像到临时图像上 cvNamedWindow("src",1);//新建窗口 cvSetMouseCallback( "src", on_mouse, 0 );//注册鼠标响应回调函数  cvShowImage("src",src);//显示图像 cvWaitKey(0);//等待按键按下  cvDestroyAllWindows();//销毁所有窗口 cvReleaseImage(&src);//释放图像 cvReleaseImage(&tmp);//释放图像 return 0;}

多目标：

#include <cv.h>#include <highgui.h>#include <stdio.h> IplImage* src = 0; IplImage* tmp = 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);//初始化字体 char temp[16];  if( (event == CV_EVENT_LBUTTONDOWN)&&(flags) )//鼠标左键按下时 { sprintf(temp,"(%d,%d)",x,y);//格式化字符串 pre_pt = cvPoint(x,y);//获取当前点坐标值 cvPutText(src,temp, pre_pt, &font, cvScalar(0,0, 0, 255));//在图像是打印字符 cvCircle( src, pre_pt, 2,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );//在图像上画圆 cvShowImage( "src", src ); cvCopy(src,tmp);//这句有没有，就是单目标和多目标的问题 } else if( (event == CV_EVENT_MOUSEMOVE) && (flags & CV_EVENT_LBUTTONDOWN)) {//鼠标移动并且鼠标左键按下 sprintf(temp,"(%d,%d)",x,y);//格式化字符串 cur_pt = cvPoint(x,y);//获取当前点坐标值  cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));//在图像是打印字符 cvRectangle(src, pre_pt, cur_pt, cvScalar(0,255,0,0), 2, 8, 0 );//在图像上画矩形 cvShowImage( "src", src ); cvCopy(tmp,src);//将img复制到临时图像tmp上，用于实时显示 } else if( event == CV_EVENT_LBUTTONUP ) {//鼠标左键弹起 sprintf(temp,"(%d,%d)",x,y);//字体格式化 cur_pt = cvPoint(x,y);//获取当前点坐标值  cvPutText(src,temp, cur_pt, &font, cvScalar(0,0, 0, 255));//在图像是打印字符 cvCircle( src, cur_pt, 2,cvScalar(255,0,0,0) ,CV_FILLED, CV_AA, 0 );//在图像上画圆 cvRectangle( src, pre_pt, cur_pt, cvScalar(0,255,0,0), 2, 8, 0 );//在图像上画矩形 cvShowImage( "src", src ); }}int main(){ src=cvLoadImage("lena.jpg",1);//读入图像 tmp=cvCloneImage(src);//复制图像到临时图像上 cvNamedWindow("src",1);//新建窗口 cvSetMouseCallback( "src", on_mouse, 0 );//注册鼠标响应回调函数  cvShowImage("src",src);//显示图像 cvWaitKey(0);//等待按键按下  cvDestroyAllWindows();//销毁所有窗口 cvReleaseImage(&src);//释放图像 cvReleaseImage(&tmp);//释放图像 return 0;}