网站关闭流程,沈阳app开发公司哪家好,湛江做网站软件,动态海报网站文章目录 前言一、设置imshow显示窗口二、绘制圆形三、绘制矩形四、绘制多边形五、示例完整代码总结 前言
本文主要讲述了在Qt下使用OpenCV的鼠标回调在OpenCV的namedWindow和imshow函数显示出来的界面上进行一些图形的绘制#xff0c;并最终将绘制好的图形显示在QLabel上。示… 文章目录 前言一、设置imshow显示窗口二、绘制圆形三、绘制矩形四、绘制多边形五、示例完整代码总结 前言
本文主要讲述了在Qt下使用OpenCV的鼠标回调在OpenCV的namedWindow和imshow函数显示出来的界面上进行一些图形的绘制并最终将绘制好的图形显示在QLabel上。示例代码见文章内容大家可以参考学习如有错误之处欢迎大家批评指正。
项目效果 提示以下是本篇文章正文内容下面案例可供参考
一、设置imshow显示窗口
这里对imshow出来的窗口进行了初始化在namedWindow函数中设置了WINDOW_NORMAL标志用来允许用户调整窗口大小。
//开始绘制区域
void Widget::startDrawArea(Mat imageMat)
{if(imageMat.empty()){QMessageBox::warning(this,警告,请先选择显示图像!);return;}//显示绘图窗口QString title 绘制区域;string strTitle title.toLocal8Bit().toStdString();namedWindow(strTitle,WINDOW_NORMAL);//设置窗口的初始位置和大小moveWindow(strTitle,690,290);resizeWindow(strTitle,400,400);//设置鼠标回调函数m_drawMat getDrawAreaMat();setMouseCallback(strTitle,mouseHandler,imageMat);//显示图像并等待用户操作imshow(strTitle,m_drawMat);waitKey(0);
}二、绘制圆形
绘制圆形的时候鼠标左键按下记录当前点位为圆心按下并移动时记录移动的距离为半径并作判断确保绘制的圆不会超出图形边界这里会实时显示绘制的圆形左键松开时结束圆的绘制。
//绘制圆形
if(m_drawCircleFlag)
{m_drawCircleFlag false;Point pt Point(x,y);m_radius norm(pt - m_center);int radiusMax std::min(m_center.x,resultMat.cols - m_center.x);radiusMax std::min(radiusMax,m_center.y);radiusMax std::min(radiusMax,resultMat.rows - m_center.y);if(m_radius radiusMax){m_radius radiusMax;}circle(resultMat, m_center, m_radius, Scalar(0, 0, 255), 1, LINE_AA);m_drawMat resultMat.clone();imshow(strTitle, m_drawMat);
}三、绘制矩形
绘制矩形的时候鼠标左键按下记录当前点位为矩形的起点按下并移动时记录当前点位为矩形的终点在移动过程中也会实时显示绘制出来的矩形左键松开时结束矩形的绘制。
//绘制矩形
if(m_drawRectFlag)
{m_drawRectFlag false;m_endPoint Point(x, y);rectangle(resultMat, Rect(m_startPoint,m_endPoint), Scalar(0, 255, 0), 1, LINE_AA);m_drawMat resultMat.clone();imshow(strTitle, m_drawMat);
}四、绘制多边形
多边形需要获取各个顶点所以这里在每次鼠标左键松开时将当前点保存到多边形顶点容器中并在获取下一个顶点时将其与前一点相连起来直到鼠标右键按下将最后一点与第一点相连结束多边形的绘制。这里每两点之间的连线使用了line函数在结束绘制时还可以使用polylines函数下面代码中有编写。
//绘制多边形
m_drawPolygonFlag false;
if(m_vPolygon.size() 2)
{//如果已经绘制了多个点,将最后一个点与第一个点连接起来line(resultMat, m_vPolygon[0], m_vPolygon.back(), Scalar(255, 0, 0), 1, LINE_AA);//或者使用polylines绘制//vectorvectorcv::Point polygons;//polygons.push_back(m_vPolygon);//polylines(resultMat, polygons, 1, Scalar(255, 0, 0), 1, LINE_AA, 0);imshow(strTitle, resultMat);
}五、示例完整代码
1.MyTest.pro 在这里我将OpenCV库的头文件和库文件打包到了OpenCV文件夹并放在项目源程序的目录下然后在pro文件中包含这个路径代码如下
#OpenCV
INCLUDEPATH $$PWD/OpenCV/Includes
DEPENDPATH $$PWD/OpenCV/Includes
LIBS -L$$PWD/OpenCV/Lib/ -lopencv_world4552.widget.h
#ifndef WIDGET_H
#define WIDGET_H#include QWidget
#include QMessageBox
#include QFileDialog
#include QDebug#include opencv2/opencv.hppusing namespace cv;
using namespace std;QT_BEGIN_NAMESPACE
namespace Ui { class Widget; }
QT_END_NAMESPACEclass Widget : public QWidget
{Q_OBJECTpublic:Widget(QWidget *parent nullptr);~Widget();Mat getDrawAreaMat();QPixmap cvMatToPixmap(const Mat imageMat);void startDrawArea(Mat imageMat);private:static void mouseHandler(int event, int x, int y, int flags, void* param);private slots:void on_pb_selectMat_clicked();void on_pb_drawCircle_clicked();void on_pb_drawRect_clicked();void on_pb_drawPolygon_clicked();private:Ui::Widget *ui;Mat m_showMat; //界面显示图像};
#endif // WIDGET_H3.widget.cpp
#include widget.h
#include ui_widget.h//全局变量
Mat m_drawMat; //绘制的图像bool m_drawCircleFlag false; //绘制圆形标志
bool m_drawRectFlag false; //绘制矩形标志
bool m_drawPolygonFlag false; //绘制多边形标志int m_radius 0; //绘制圆的半径
Point m_center Point(); //绘制圆的圆心
Point m_startPoint Point(); //绘制矩形的起点
Point m_endPoint Point(); //绘制矩形的终点
vectorPoint m_vPolygon; //多边形的顶点容器Widget::Widget(QWidget *parent): QWidget(parent), ui(new Ui::Widget)
{ui-setupUi(this);this-setFixedSize(650,420);
}Widget::~Widget()
{delete ui;
}//显示绘制的区域
Mat Widget::getDrawAreaMat()
{//绘制圆Mat showMat m_showMat.clone();if((m_radius ! 0) (m_center ! Point(0,0))){circle(showMat, m_center, m_radius, Scalar(0, 0, 255), 1, LINE_AA);}//绘制矩形if((m_startPoint ! Point(0,0)) (m_endPoint ! Point(0,0))){rectangle(showMat, Rect(m_startPoint,m_endPoint), Scalar(0, 255, 0), 1, LINE_AA);}//绘制多边形int vNum m_vPolygon.size();for(int i1;ivNum;i){line(showMat, m_vPolygon[i-1], m_vPolygon[i], Scalar(255, 0, 0), 1, LINE_AA);if(i vNum-1){line(showMat, m_vPolygon[0], m_vPolygon.back(), Scalar(255, 0, 0), 1, LINE_AA);}}return showMat;
}//Mat转QPixmap
QPixmap Widget::cvMatToPixmap(const Mat imageMat)
{QImage showImage;if(imageMat.channels() 1){showImage QImage((const unsigned char*)(imageMat.data),imageMat.cols,imageMat.rows,imageMat.step,QImage::Format_RGB888); //彩色图}else{showImage QImage((const unsigned char*)(imageMat.data),imageMat.cols,imageMat.rows,imageMat.step,QImage::Format_Indexed8); //灰度图}//OpenCV使用BGR顺序,而Qt使用RGB顺序,因此需要交换颜色通道return QPixmap::fromImage(showImage.rgbSwapped());
}//开始绘制区域
void Widget::startDrawArea(Mat imageMat)
{if(imageMat.empty()){QMessageBox::warning(this,警告,请先选择显示图像!);return;}//显示绘图窗口QString title 绘制区域;string strTitle title.toLocal8Bit().toStdString();namedWindow(strTitle,WINDOW_NORMAL);//设置窗口的初始位置和大小moveWindow(strTitle,690,290);resizeWindow(strTitle,400,400);//设置鼠标回调函数m_drawMat getDrawAreaMat();setMouseCallback(strTitle,mouseHandler,imageMat);//显示图像并等待用户操作imshow(strTitle,m_drawMat);waitKey(0);
}//鼠标回调函数
void Widget::mouseHandler(int event, int x, int y, int flags, void* param)
{QString title 绘制区域;string strTitle title.toLocal8Bit().toStdString();Mat resultMat *(Mat*)param;if(event EVENT_LBUTTONDOWN) //鼠标左键按下{//绘制圆,确定圆心if(m_drawCircleFlag){m_center Point(x,y);}//绘制矩形,确定起点if(m_drawRectFlag){m_startPoint Point(x,y);}}else if(event EVENT_MOUSEMOVE (flags EVENT_FLAG_LBUTTON)) //左键按下并移动{//实时显示绘制的圆if(m_drawCircleFlag){//计算半径Point pt Point(x,y);m_radius norm(pt - m_center);//确保圆不会超出图像边界int radiusMax std::min(m_center.x,resultMat.cols - m_center.x);radiusMax std::min(radiusMax,m_center.y);radiusMax std::min(radiusMax,resultMat.rows - m_center.y);if(m_radius radiusMax){m_radius radiusMax;}m_drawMat resultMat.clone();circle(m_drawMat, m_center, m_radius, Scalar(0, 0, 255), 1, LINE_AA);imshow(strTitle, m_drawMat);}//实时显示绘制的矩形if(m_drawRectFlag){m_endPoint Point(x, y);m_drawMat resultMat.clone();rectangle(m_drawMat, Rect(m_startPoint,m_endPoint), Scalar(0, 255, 0), 1, LINE_AA);imshow(strTitle, m_drawMat);}}else if(event EVENT_LBUTTONUP) //鼠标左键抬起{//结束绘制圆if(m_drawCircleFlag){m_drawCircleFlag false;Point pt Point(x,y);m_radius norm(pt - m_center);int radiusMax std::min(m_center.x,resultMat.cols - m_center.x);radiusMax std::min(radiusMax,m_center.y);radiusMax std::min(radiusMax,resultMat.rows - m_center.y);if(m_radius radiusMax){m_radius radiusMax;}circle(resultMat, m_center, m_radius, Scalar(0, 0, 255), 1, LINE_AA);m_drawMat resultMat.clone();imshow(strTitle, m_drawMat);}//结束绘制矩形if(m_drawRectFlag){m_drawRectFlag false;m_endPoint Point(x, y);rectangle(resultMat, Rect(m_startPoint,m_endPoint), Scalar(0, 255, 0), 1, LINE_AA);m_drawMat resultMat.clone();imshow(strTitle, m_drawMat);}//绘制多边形的各顶点if(m_drawPolygonFlag){m_vPolygon.push_back(Point(x, y));for(size_t i 1; i m_vPolygon.size(); i){line(resultMat, m_vPolygon[i-1], m_vPolygon[i], Scalar(255, 0, 0), 1, LINE_AA);}imshow(strTitle, resultMat);}}else if(event EVENT_RBUTTONDOWN) //鼠标右键按下{//结束绘制多边形m_drawPolygonFlag false;if(m_vPolygon.size() 2){//如果已经绘制了多个点,将最后一个点与第一个点连接起来line(resultMat, m_vPolygon[0], m_vPolygon.back(), Scalar(255, 0, 0), 1, LINE_AA);//或者使用polylines绘制//vectorvectorcv::Point polygons;//polygons.push_back(m_vPolygon);//polylines(resultMat, polygons, 1, Scalar(255, 0, 0), 1, LINE_AA, 0);imshow(strTitle, resultMat);}}
}//选择图像
void Widget::on_pb_selectMat_clicked()
{QString fileName QFileDialog::getOpenFileName(this,选择图像文件,E:/PhotoTest/myPhoto,Image Files(*.png *.jpg *.bmp));if(!fileName.isEmpty()){m_showMat imread(fileName.toLocal8Bit().toStdString(),1);//更新界面显示QPixmap showPixmap cvMatToPixmap(m_showMat);if(!showPixmap.isNull()){ui-lb_showMat-setPixmap(showPixmap.scaled(ui-lb_showMat-size(),Qt::KeepAspectRatio,Qt::SmoothTransformation)); //保持比例}else{QMessageBox::warning(this,警告,图像文件打开失败!);}}
}//绘制圆形
void Widget::on_pb_drawCircle_clicked()
{setEnabled(false);m_drawCircleFlag true;m_drawRectFlag false;m_drawPolygonFlag false;m_radius 0;m_center Point(0,0);startDrawArea(m_showMat.clone());//更新界面显示QPixmap showPixmap cvMatToPixmap(getDrawAreaMat());if(!showPixmap.isNull()){ui-lb_showMat-setPixmap(showPixmap.scaled(ui-lb_showMat-size(),Qt::KeepAspectRatio,Qt::SmoothTransformation));}setEnabled(true);
}//绘制矩形
void Widget::on_pb_drawRect_clicked()
{//点击后禁用窗口交互setEnabled(false);m_drawCircleFlag false;m_drawRectFlag true;m_drawPolygonFlag false;m_startPoint Point(0,0);m_endPoint Point(0,0);startDrawArea(m_showMat.clone());QPixmap showPixmap cvMatToPixmap(getDrawAreaMat());if(!showPixmap.isNull()){ui-lb_showMat-setPixmap(showPixmap.scaled(ui-lb_showMat-size(),Qt::KeepAspectRatio,Qt::SmoothTransformation));}//绘制结束后开启交互setEnabled(true);
}//绘制多边形
void Widget::on_pb_drawPolygon_clicked()
{setEnabled(false);m_drawCircleFlag false;m_drawRectFlag false;m_drawPolygonFlag true;m_vPolygon.clear();startDrawArea(m_showMat.clone());QPixmap showPixmap cvMatToPixmap(getDrawAreaMat());if(!showPixmap.isNull()){ui-lb_showMat-setPixmap(showPixmap.scaled(ui-lb_showMat-size(),Qt::KeepAspectRatio,Qt::SmoothTransformation));}setEnabled(true);
}4.widget.ui
总结
在Qt下使用OpenCV务必要配置好环境这样才能正常使用OpenCV的函数。可以看到在这个示例中使用的都是一些基本的函数但是很好的实现了本文标题所写的功能。在本人之前的文章中也有使用Qt的事件过滤器来实现这个功能见下文参考博客。 hello 共同学习共同进步如果还有相关问题可在评论区留言进行讨论。
参考博客Qt实现在QLabel上显示图片并进行线条/矩形框/多边形的绘制
