如何使用OpenCV通过鼠标绘制并截取矩形区域图像？

2026-05-08 17:503阅读0评论SEO资讯

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本文将分享一个OpenCV鼠标绘制矩形区域图像的简单示例代码。以下是大致内容：

在OpenCV中使用鼠标绘制矩形区域，代码如下：

pythonimport cv2

初始化鼠标回调函数def mouse_callback(event, x, y, flags, param): if event==cv2.EVENT_LBUTTONDOWN: param['x1'], param['y1']=x, y elif event==cv2.EVENT_MOUSEMOVE: if flags & cv2.EVENT_FLAG_LBUTTON: param['x2'], param['y2']=x, y elif event==cv2.EVENT_LBUTTONUP: param['x2'], param['y2']=x, y param['draw']=True

创建空白图像image=np.zeros((400, 400, 3), dtype=np.uint8)cv2.namedWindow('image')cv2.setMouseCallback('image', mouse_callback)

保存鼠标参数mouse_params={'x1': 0, 'y1': 0, 'x2': 0, 'y2': 0, 'draw': False}

while True: cv2.imshow('image', image) if mouse_params['draw']: cv2.rectangle(image, (mouse_params['x1'], mouse_params['y1']), (mouse_params['x2'], mouse_params['y2']), (0, 255, 0), 2) mouse_params['draw']=False

if cv2.waitKey(20) & 0xFF==27: break

cv2.destroyAllWindows()

以上代码展示了如何使用OpenCV库在图像上通过鼠标绘制矩形。

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：

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自由互联。

标签：opencv 鼠标绘制矩形和