qt中打开摄像头

1. 确保你已经设置好了OpenCV环境

    首先做成这么一个界面

   

2.在头文件中

   就是你创建Qt GUI的时候生成的代码的那个头文件

#ifndef CAMERAQT_H
#define CAMERAQT_H
#include <QTimer>
#include <QFont>
#include <QtGui/QMainWindow>
#include "ui_cameraqt.h"
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv2/core/core.hpp>
using namespace cv;
class CameraQt : public QMainWindow
{
	Q_OBJECT

public:
	CameraQt(QWidget *parent = 0, Qt::WFlags flags = 0);
	~CameraQt();
public slots:
	void OpenCamera();
	void ReadFram();
signals:
	void opensuccess();
private:
	Ui::CameraQtClass ui;
	CvCapture* Cam;
	IplImage *frame;
	QTimer* timer;
	QImage* image;
	QFont ft;
};

#endif // CAMERAQT_H

3.在实现文件中

#include "cameraqt.h"

CameraQt::CameraQt(QWidget *parent, Qt::WFlags flags)
	: QMainWindow(parent, flags)
{

	ui.setupUi(this);
	ft.setPointSize(56);
	ft.setItalic(true);
	ui.label->setFont(ft);
	Cam=NULL;
	timer =new QTimer(this);
	image=new QImage();
	connect(timer,SIGNAL(timeout()),this,SLOT(ReadFram()));
	connect(ui.pushButton,SIGNAL(clicked()),this,SLOT(OpenCamera()));
	connect(ui.actionClose,SIGNAL(triggered()),this,SLOT(close()));

}

CameraQt::~CameraQt()
{

}
void CameraQt::OpenCamera()
{
	Cam=cvCreateCameraCapture(0);
	timer->start(33);
}
void CameraQt::ReadFram()
{ 	
		Cam=cvCreateCameraCapture(0);
		frame=cvQueryFrame(Cam);
		QImage image((const uchar*)frame->imageData,frame->width,frame->height,QImage::Format_RGB888);
		ui.label->setPixmap(QPixmap::fromImage(image));	
	
}

4.显示结果