Question

在.pro文件中：

QT       += core

QT       -= gui

TARGET    = latihan_2
CONFIG   += console
CONFIG   -= app_bundle

TEMPLATE = app

SOURCES += main.cpp

INCLUDEPATH += E:\OpenCV\OpenCV\opencv\build\include

LIBS += E:\OpenCV\OpenCV\opencv\build\x86\mingw\lib\libopencv_core246.dll.a
LIBS += E:\OpenCV\OpenCV\opencv\build\x86\mingw\lib\libopencv_highgui246.dll.a
LIBS += E:\OpenCV\OpenCV\opencv\build\x86\mingw\lib\libopencv_imgproc246.dll.a
LIBS += E:\OpenCV\OpenCV\opencv\build\x86\mingw\lib\libopencv_features2d246.dll.a
LIBS += E:\OpenCV\OpenCV\opencv\build\x86\mingw\lib\libopencv_calib3d246.dll.a

在main.cpp：

#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>

using namespace cv;

int main(){
    //read image
    Mat image = imread("img.jpg", 1);
    //create image window named "My image"
    namedWindow("My Image", CV_WINDOW_AUTOSIZE);
    //show the image on window
    imshow("My image", image);
    //wait key for 5000ms
    waitKey(5000);
    return 1;
    }

当我点击运行时，没有错误，但它只显示一个名为qtcreator_process_stub.exe的黑色窗口。

为什么“我的图像”窗口没有显示出来并显示img.jpg？我使用基于Qt 5.1.1的Qt creator 2.8.1和openCV-2.4.6.0。

Answer 1

您还可以在Qt窗口上显示cv::Mat。我演示了如何在cvImage上执行此操作。检查cvImage::_open()：

的实施情况

void cvImage::_open()
{
    // Display dialog so the user can select a file
    QString filename = QFileDialog::getOpenFileName(this,
                                                    tr("Open Image"),
                                                    QDir::currentPath(),
                                                    tr("Files (*.png *.jpg *.tiff *.bmp)"));

    if (filename.isEmpty()) // Do nothing if filename is empty
        return;

    cv::Mat img = cv::imread(filename.toStdString());
    if (img.empty())
        return;

    // Since OpenCV uses BGR order, we need to convert it to RGB
    cv::cvtColor(img, img, CV_BGR2RGB);

    // _image is created according to Mat dimensions
    if (_image)
    {
        delete _image;
    }
    _image = new QImage(img.size().width, img.size().height, QImage::Format_RGB888);

    // Copy cv::Mat to QImage
    memcpy(_image->scanLine(0), (unsigned char*)img.data, _image->width() * _image->height() * img.channels());

    // Set the filename as the window title
    setWindowTitle(filename);

    // Resize the window to fit video dimensions
    resize(img.size().width, img.size().height);

    // Mouse move events will occur only when a mouse button is pressed down,
    // unless mouse tracking has been enabled:
    QWidget::setMouseTracking(true);

    // Trigger paint event to redraw the window
    update();
}

Answer 2

首先猜测图像是在错误的路径上，因此首先应该测试图像的完整路径。

同时检查程序的返回值（确保它不会返回一些崩溃错误代码 - 保持一致并返回0表示成功，其他值表示失败）。

一些编码告诉你代码失败的地方并没有什么坏处，所以检查image.data或者你也可以使用image.empty()：

if(! image.data )
{
    std::cout << "No image to display";
    //can be any other method to display the error: qDebug, a messagebox... 
    //you can also 
    return 1;   
}
else
{
    //use the image
    //if nothing goes wrong:
    //return 0; 
}

Answer 3

检查项目 - ＆gt;运行设置 - ＆gt;在终端中运行复选框。如果已禁用，请启用它。

Answer 4

我遇到了同样的问题，并通过修复路径环境变量解决了它。在我的路径环境变量中，我错误地添加了一些opencv文件夹，然后删除了它们，仅添加了opencv DLL的bin文件夹，然后问题得以解决。

OpenCV，Qt，imread，namedWindow，imshow不起作用

4 个答案: