QGraphicsview 显示图片，鼠标框选获取图片选区，OpenCV 显示ROI矩形选区。

#include "mainwindow.h" #include "ui_mainwindow.h" #include<QGraphicsItem> MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent) , ui(new Ui::MainWindow) { ui->setupUi(this); ImageViewscene =new QGraphicsScene(this); ImagePix =new QGraphicsPixmapItem(); Rectang =new QGraphicsRectItem(); //矩形 ImageViewscene->addItem(ImagePix); ImageViewscene->addItem(Rectang); ui->graphicsView->setScene(ImageViewscene); //待检测图片以及检测图片绑定场景 QObject::connect(ui->graphicsView,SIGNAL(mouseClickedPoint(QPoint)), this, SLOT(on_mouseClickedPoint(QPoint))); QObject::connect(ui->graphicsView,SIGNAL(mouseMovePoint(QPoint)), this, SLOT(on_mouseMovePoint(QPoint))); QObject::connect(ui->graphicsView,SIGNAL(mouseReleasePoint(QPoint)), this, SLOT(on_mouseReleasePoint(QPoint))); } MainWindow::~MainWindow() { delete ui; } //void MainWindow::on_pushButton_clicked() //{ // GlobalImg= imread("D:/123.png"); // Rect rect(2000,2000, 200, 200); // Mat ROI = GlobalImg(rect); // imshow("ROI_WIN",ROI); //} void MainWindow::on_mouseClickedPoint(QPoint point) //鼠标移动 { QPointF pointScene=ui->graphicsView->mapToScene(point); //转换到Scene坐标 StartPoint = pointScene; } void MainWindow::on_mouseMovePoint(QPoint point) { QPointF pointScene=ui->graphicsView->mapToScene(point); //转换到Scene坐标 EndPoint=pointScene; QPen RedPen(Qt::red); ImageViewscene->removeItem(Rectang); Rectang->setPen(RedPen); Rectang->setRect(StartPoint.x(), StartPoint.y(),EndPoint.x()-StartPoint.x(), EndPoint.y()-StartPoint.y()); ImageViewscene->addItem(Rectang); qDebug()<<StartPoint<<EndPoint; } void MainWindow::on_mouseReleasePoint(QPoint point) { QPointF pointScene=ui->graphicsView->mapToScene(point); //转换到Scene坐标 EndPoint=pointScene; QPen RedPen(Qt::red); ImageViewscene->removeItem(Rectang); ImageViewscene->addRect(StartPoint.x(), StartPoint.y(),EndPoint.x()-StartPoint.x(), EndPoint.y()-StartPoint.y(),RedPen); Rect rect(StartPoint.x(), StartPoint.y(),EndPoint.x()-StartPoint.x(), EndPoint.y()-StartPoint.y()); Mat ROI = GlobalImg(rect); //截取感兴趣区域 QImage imgROI =Mat2QImage(ROI); ui->label->setPixmap(QPixmap::fromImage(imgROI)); ui->label->setScaledContents(true); } void MainWindow::on_OpenImage_clicked() { QString filename1=QFileDialog::getOpenFileName(this,QStringLiteral("打开图片"),"../"); if(filename1.isEmpty()==false) { cv::String cvfilename1=filename1.toLocal8Bit().toStdString();//转换为OpenCV路径 GlobalImg=imread(cvfilename1); cvtColor(GlobalImg,GlobalImg,CV_BGR2RGB); Rect rect(2000,2000, 200, 200); Mat ROI = GlobalImg(rect); //截取感兴趣区域 QImage imgROI =Mat2QImage(ROI); QImage img = QImage((const unsigned char*)(GlobalImg.data),GlobalImg.cols,GlobalImg.rows, GlobalImg.cols*GlobalImg.channels(), QImage::Format_RGB888); ImageViewscene->addPixmap(QPixmap::fromImage(img)); ui->label->setPixmap(QPixmap::fromImage(imgROI)); ui->label->setScaledContents(true); QPen GreenPen(Qt::red); ImageViewscene->addLine(0,ImageViewscene->height()/2.0,ImageViewscene->width(),ImageViewscene->height()/2.0,GreenPen); ImageViewscene->addLine(ImageViewscene->width()/2.0,0,ImageViewscene->width()/2.0,ImageViewscene->height(),GreenPen); //设置0点标识 } qDebug()<<ImageViewscene->width()<<ImageViewscene->height(); } //Mat图像转Qimage图像 QImage MainWindow::Mat2QImage(const cv::Mat& InputMat) { cv::Mat TmpMat; QImage Result; if (InputMat.channels() == 1) { cv::cvtColor(InputMat, TmpMat, CV_GRAY2RGB); Result = QImage((const uchar*)(TmpMat.data), TmpMat.cols, TmpMat.rows, TmpMat.cols*TmpMat.channels(), QImage::Format_Indexed8); } else { cv::cvtColor(InputMat, TmpMat, CV_BGR2RGB); Result = QImage((const uchar*)(TmpMat.data), TmpMat.cols, TmpMat.rows, TmpMat.cols*TmpMat.channels(), QImage::Format_RGB888); } Result.bits(); return Result; }