一. 安装OpenCV库：

打开终端，输入以下命令安装OpenCV：

sudo apt-get update
sudo apt-get install libopencv-dev

二. 配置Qt项目

在Qt Creator中打开项目，然后编辑.pro文件，添加以下内容：

INCLUDEPATH += /usr/include/opencv4
LIBS += -L/usr/lib/x86_64-linux-gnu -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_imgcodecs
CONFIG(use_opencv_4){
    PKG_CONFIG_PATH=$PKG_CONFIG_PATH:/usr/local/lib/pkgconfig
    CV_CONFIG = "opencv4"
}
 
!isEmpty(CV_CONFIG):{
    message("Using OpenCV version $$CV_CONFIG")
    PKGCONFIG += $$CV_CONFIG
} else {
    message("Neither OpenCV 3 nor OpenCV 4 found - will use OpenCV 3.")
    LIBS += -lopencv_core -lopencv_imgproc -lopencv_highgui -lopencv_imgcodecs
}

三. 测试

#include <opencv2/opencv.hpp>
#include <QImage>
#include <QLabel>
 
int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
 
    cv::Mat img = cv::imread("path_to_image.jpg");
    if(img.empty()) {
        return -1;
    }
 
    cv::cvtColor(img, img, cv::COLOR_BGR2RGB);
    QImage qImg = QImage((const unsigned char*)(img.data), img.cols, img.rows, img.step, QImage::Format_RGB888);
 
    QLabel label;
    label.setPixmap(QPixmap::fromImage(qImg));
    label.show();
 
    return app.exec();
}