QT学习之usb摄像头采集(Opencv+QT)[cvCapture,IplImage,QImage]

参考自:http://blog.chinaunix.net/uid-23381466-id-3826748.html

 

将Opencv中的cvCaptureFromCAM不断获得摄像头采集到的图像数据,

QT中通过QImage,QPixMap,label控件显示图像到dlg的窗口中.

还用到了一个定时器间隔的从摄像头获得图像进行显示.

(这种实时图像处理的程序,要么定时器,要么多线程,最好不要用sleep这种~)

 

创建QT widgets工程,起名 mywindow

俩按钮,一个label控件,save暂时没用到

头文件:

mywindow.h

#ifndef MYWINDOW_H
#define MYWINDOW_H

#include <QMainWindow>
#include <QtCore>
#include <QLabel>
#include <QTime>
#include <opencv2/opencv.hpp>

namespace Ui {
class myWindow;
}

class myWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit myWindow(QWidget *parent = 0);
    ~myWindow();

private slots:
    void on_pushButton_clicked();
    void getOneFrame();

private:
    Ui::myWindow *ui;

    IplImage* pFrame;
    CvCapture* pCap;
    int startedFlag;

    QTimer *timer;

    //QLabel *label;
};

#endif // MYWINDOW_H

mywindow.cpp:

#include "mywindow.h"
#include "ui_mywindow.h"
#include <opencv2/opencv.hpp>


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

    startedFlag = false;
    timer = new QTimer(this);
    pCap = NULL;
    pFrame = NULL;

    connect(timer, SIGNAL(timeout()), this, SLOT(getOneFrame()));

}

myWindow::~myWindow()
{
    delete ui;
}
void myWindow::getOneFrame()
{
    pFrame = cvQueryFrame(pCap);
    QImage img = QImage((uchar*)pFrame->imageData, pFrame->width,pFrame->height, pFrame->widthStep,  QImage::Format_RGB888).rgbSwapped();
    int height = img.height()/2;
    int width  = img.width()/2;

    ui->label->resize(width, height);
    ui->label->setPixmap(QPixmap::fromImage(img.scaled(width,height)));//将图像长宽缩放一半显示
}

void myWindow::on_pushButton_clicked()
{
    if (startedFlag == false)
    {
        startedFlag = true;
        ui->pushButton->setText("stop");
        pCap = cvCaptureFromCAM(0);
        timer->start(33);

    }else
    {
        startedFlag = false;
        ui->pushButton->setText("start");
        timer->stop();
        cvReleaseCapture(&pCap);
        ui->label->clear();

    }
}

main.cpp:

#include "mywindow.h"
#include <QApplication>
#include <opencv2/opencv.hpp>

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    myWindow w;
    w.show();

    return a.exec();
}