我正在 Qt 中构建一个简单的 GUI 来在 OpenCV 中执行一些图像处理。我想使用多线程，以便即使处理变得非常密集，GUI 也能做出响应。为此，我参考以下章节来构建我的框架：
http://www.informit.com/articles/article.aspx?p=1405551&seqNum=3
首先，我有 2 个按钮，一个用于加载图像，另一个用于处理图像。
我有 2 个标签，一个用于显示输入图像，一个用于显示处理后的图像。
到目前为止，我正在使用主线程中的插槽和信号机制加载我的输入图像，并且我正在为图像翻转创建一个新线程。
但是，当我构建代码时，出现错误
架构 x86_64 的未定义符号：
“FlipTransaction::FlipTransaction(int)”，引用自：mainwindow.o ld 中的 MainWindow::flipHorizontally()：未找到架构 x86_64 的符号
当我注释掉插槽 flipHorizontally() 时，我的代码构建良好并且能够加载图像。
因此我的处理没有被执行。
下面是我的代码。任何帮助表示赞赏
主窗口.h
#ifndef MAINWINDOW_H
#define MAINWINDOW_H
#include <QMainWindow>
#include <QFileDialog>
#include <QStatusBar>
// OpenCV Headers
#include <opencv2/core/core.hpp>
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp> // for cvtColor
// Multi-Threading Headers
#include <QThread>
#include <QMutex>
#include <QQueue>
#include <QWaitCondition>
namespace Ui {
class MainWindow;
}
class Transaction
{
public:
virtual ~Transaction() {}
virtual QImage apply(const cv::Mat source_image, cv::Mat dest_image) = 0;
virtual QString message() = 0;
};
class TransactionThread : public QThread
{
Q_OBJECT
public:
TransactionThread();
~TransactionThread();
void addTransaction(Transaction *transact);
void setImage(const QImage &image);
QImage image();
signals:
void transactionStarted(const QString &message);
void allTransactionsDone();
protected:
void run();
private:
QImage currentImage;
Transaction *EndTransaction;
QQueue<Transaction *> transactions;
QWaitCondition transactionAdded;
QMutex mutex;
cv::Mat source_image;
cv::Mat dest_image;
};
class FlipTransaction : public Transaction
{
public:
FlipTransaction(int orientation);
QImage apply(const cv::Mat source_image, cv::Mat dest_image);
QString message();
private:
int orientation;
};
class MainWindow : public QMainWindow
{
Q_OBJECT
public:
explicit MainWindow(QWidget *parent = 0);
~MainWindow();
private:
void addTransaction(Transaction *transact);
void drawOut(QImage qimg);
private slots:
void on_pushButton_clicked();
public slots:
void flipHorizontally();
void allTransactionsDone();
private:
Ui::MainWindow *ui;
public:
TransactionThread thread;
cv::Mat source_image; // Input Image Variable
cv::Mat dest_image; // Output Image Variable
};
#endif // MAINWINDOW_H
主窗口.cpp
#include "mainwindow.h"
#include "ui_mainwindow.h"
MainWindow::MainWindow(QWidget *parent) :
QMainWindow(parent),
ui(new Ui::MainWindow)
{
ui->setupUi(this);
statusBar()->showMessage(tr("Ready"), 2000);
connect(&thread, SIGNAL(transactionStarted(const QString &)),
statusBar(), SLOT(showMessage(const QString &)));
connect(&thread, SIGNAL(allTransactionsDone()),
this, SLOT(allTransactionsDone()));
}
MainWindow::~MainWindow()
{
delete ui;
}
void MainWindow::drawOut(QImage qimg)
{
// Display on Label
ui->outputLabel->setPixmap(QPixmap::fromImage(qimg));
// Resize the label to fit the image
ui->outputLabel->resize(ui->outputLabel->pixmap()->size());
}
void MainWindow::addTransaction(Transaction *transact)
{
MainWindow::thread.addTransaction(transact);
}
void MainWindow::on_pushButton_clicked()
{
QString filename = QFileDialog::getOpenFileName(this,
tr("Open Image"), ".",tr("Image Files (*.png *.jpg *.jpeg *.bmp *.gif)"));
// Read Image
source_image = cv::imread(filename.toAscii().data());
// Resize Image
cv::resize(source_image, source_image, cv::Size(128,128) , 0, 0);
// Change to RGB format
cv::cvtColor(source_image,source_image,CV_BGR2RGB);
// Convert to QImage
QImage qimg = QImage((const unsigned char*) source_image.data, source_image.cols, source_image.rows, QImage::Format_RGB888); // convert to QImage
// Display on Input Label
ui->inputLabel->setPixmap(QPixmap::fromImage(qimg));
// Resize the label to fit the image
ui->inputLabel->resize(ui->inputLabel->pixmap()->size());
}
void MainWindow::flipHorizontally()
{
MainWindow::thread.addTransaction(new FlipTransaction(int(1)));
}
void MainWindow::allTransactionsDone()
{
statusBar()->showMessage(tr("Ready"), 2000);
}
TransactionThread::TransactionThread()
{
start();
}
TransactionThread::~TransactionThread()
{
{
QMutexLocker locker(&mutex);
while(!transactions.isEmpty())
delete transactions.dequeue();
transactions.enqueue(EndTransaction);
transactionAdded.wakeOne();
}
wait();
}
void TransactionThread::addTransaction(Transaction *transact)
{
QMutexLocker locker(&mutex);
transactions.enqueue(transact);
transactionAdded.wakeOne();
}
void TransactionThread::setImage(const QImage &image)
{
QMutexLocker locker(&mutex);
currentImage = image;
}
QImage TransactionThread::image()
{
QMutexLocker locker(&mutex);
return currentImage;
}
void TransactionThread::run()
{
Transaction *transact = 0;
QImage oldImage;
forever {
{
QMutexLocker locker(&mutex);
if (transactions.isEmpty())
transactionAdded.wait(&mutex);
transact = transactions.dequeue();
if (transact == EndTransaction)
break;
oldImage = currentImage;
}
emit transactionStarted(transact->message());
QImage newImage = transact->apply(source_image, dest_image);
// QImage newImage = transact->apply(oldImage);
delete transact;
{
QMutexLocker locker(&mutex);
currentImage = newImage;
if (transactions.isEmpty())
emit allTransactionsDone();
}
}
}
QImage FlipTransaction::apply(const cv::Mat source_image, cv::Mat dest_image)
{
// Process Image
cv::flip(source_image, dest_image, orientation);
// Change to RGB format
cv::cvtColor(dest_image,dest_image,CV_BGR2RGB);
// Convert to QImage
QImage qimg = QImage((const unsigned char*) dest_image.data, dest_image.cols, dest_image.rows, QImage::Format_RGB888);
return qimg;
}
QString FlipTransaction::message()
{
if (orientation == 1) {
return QObject::tr("Flipping image horizontally...");
} else {
return QObject::tr("Flipping image vertically...");
}
}