No fluid image with QGraphicView and QGraphicScene

[GonzoFist]

Hi together, so I got a little problem.

I got a webcam, and the with many other tutorials I managed to convert its OpenCv Image to an QImage. For displaying it to the desktop I use a GraphicsView.
The QImage gets put into a QGraphicsScene, and this finally gets showed in the GraphicsView.
A QTimer which is activated every 100ms, catchs a Image from the Wcam, transfers it to a QImage. And then it gets showed.
But now the Problem is that the picture in the viewer isn't fluid. The transfering from OpenCv to QImage isnt a problem. I think theres a problem with updating the qimage,scene or viewer.

out of CameraCalibrator.cpp

bool CameraCalibrator::refreshImage()
{   
	IplImage* img = mCam->grab();
	if (img)
	{
	  mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(img))); 
	  mScene->update(0,0,mScene->width(),mScene->height());
	  return true;
	}
	return false;
}
 
bool CameraCalibrator::Connect()
{
	mCam->vrmLogger();
	if (mCam->connect())
	{
		IplImage* iImage = mCam->grab();
		mScene = new QGraphicsScene(this);
		mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(iImage))); 
		resize(width()+(mScene->width()- mViewer->width()),height()+(mScene->height()-mViewer->height()));
		mViewer->setScene(mScene);
		mViewer->setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
		mActionLoad->setEnabled(true);
		mActionSave->setEnabled(true);
		mActionMatch->setEnabled(true);
		mTimer = new QTimer();
		connect(mTimer, SIGNAL(timeout()), this, SLOT(refreshImage()));
		mTimer->start(1000/10);
		return true;
	}
	else
	{
		mActionLoad->setEnabled(false);
		mActionSave->setEnabled(false);
		mActionMatch->setEnabled(false);
		return false;
	}
}

bool CameraCalibrator::refreshImage()
{   
	IplImage* img = mCam->grab();
	if (img)
	{
	  mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(img))); 
	  mScene->update(0,0,mScene->width(),mScene->height());
	  return true;
	}
	return false;
}

bool CameraCalibrator::Connect()
{
	mCam->vrmLogger();
	if (mCam->connect())
	{
		IplImage* iImage = mCam->grab();
		mScene = new QGraphicsScene(this);
		mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(iImage))); 
		resize(width()+(mScene->width()- mViewer->width()),height()+(mScene->height()-mViewer->height()));
		mViewer->setScene(mScene);
		mViewer->setViewportUpdateMode(QGraphicsView::FullViewportUpdate);
		mActionLoad->setEnabled(true);
		mActionSave->setEnabled(true);
		mActionMatch->setEnabled(true);
		mTimer = new QTimer();
		connect(mTimer, SIGNAL(timeout()), this, SLOT(refreshImage()));
		mTimer->start(1000/10);
		return true;
	}
	else
	{
		mActionLoad->setEnabled(false);
		mActionSave->setEnabled(false);
		mActionMatch->setEnabled(false);
		return false;
	}
}

To copy to clipboard, switch view to plain text mode 

out of CameraCalibrator.h

QTimer* mTimer;
	QGraphicsView* mViewer;
	QGraphicsScene* mScene;

QTimer* mTimer;
	QGraphicsView* mViewer;
	QGraphicsScene* mScene;

To copy to clipboard, switch view to plain text mode 

These are the two important functions. Does anyone else see the failure?
I really dont get it.

[spud]

mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(img)));

mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(img)));

To copy to clipboard, switch view to plain text mode 

You should only call addPixmap() once. Otherwise all the previous frames remain in the scene behind the current frame.
Keep a reference instead:

// Do once:
 QGraphicsPixmapItem* pixItem = mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(img))); 
 
 
// Update:
pixItem->setPixmap(QPixmap::fromImage(IplImageToQImage(img)));

// Do once:
 QGraphicsPixmapItem* pixItem = mScene->addPixmap(QPixmap::fromImage(IplImageToQImage(img))); 


// Update:
pixItem->setPixmap(QPixmap::fromImage(IplImageToQImage(img)));

To copy to clipboard, switch view to plain text mode 

No need to call update(). The item takes care of that for itself.

[GonzoFist]

Thx very much it worked!