C++入门：Qt配置opencv库--使用qmake

下载opencv地址：

https://sourceforge.net/projects/opencvlibrary/files/

QtCreateor配置opencv库

1、将opencv解压安装到当前项目下，本人安装的是opencv-4.10.0-windows.exe
2、加上环境变量：D:\xxx\xxx\opencv\build\x64\vc16\bin
3、当前项目右键->添加库->外部库，如下图配置
4、配置完后，自动在.pro文件下追加

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/opencv/build/x64/vc16/lib/ -lopencv_world4100
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/opencv/build/x64/vc16/lib/ -lopencv_world4100d

INCLUDEPATH += $$PWD/opencv/build/include
DEPENDPATH += $$PWD/opencv/build/include

4、当前项目右键->清除->重新构建

编写代码

#include "mainwindow.h"
#include "ui_mainwindow.h"
#include <QFileDialog>
#include <QDebug>
#include <opencv2/opencv.hpp>

using namespace cv;

MainWindow::MainWindow(QWidget *parent)
    : QMainWindow(parent)
    , ui(new Ui::MainWindow)
{
    ui->setupUi(this);
}

MainWindow::~MainWindow()
{
    delete ui;
}


void MainWindow::on_pushButton_clicked()
{
    QString imagePath = QFileDialog::getOpenFileName(this,"打开图片","D:/","(打开(*.png *.jpg *.bmp))");
    Mat cvImage = imread(imagePath.toStdString());
    if (cvImage.empty()) {
        qDebug() << "Failed to load image";
        return;
    }
    Mat image1;
    cvtColor(cvImage,image1,COLOR_BGR2RGB);
    QImage image((const unsigned char*)(image1.data), image1.cols, image1.rows, image1.step, QImage::Format_RGB888);
    // 调整label的大小
    int width = image1.cols;
    int height = image1.rows;
    if(width>600 && height>600){
      double scale_percent = 50.0;
      width = static_cast<int>(image1.cols * scale_percent / 100);
      height = static_cast<int>(image1.rows * scale_percent / 100);
    }
    QSize labelSize(width, height);
    // 设置label的大小
    ui->label->setFixedSize(labelSize);
    // 在label上显示图像并填充
    ui->label->setPixmap(QPixmap::fromImage(image));
    ui->label->setScaledContents(true);
    ui->label->setAlignment(Qt::AlignCenter);

}