QGraphicsRectItem coordinate system on image resize

sayan275

On an image(x by y), a QGraphicsRectItem is added, Let say Qrect(73, 77, 43, 28) Qrect(x,y,w,h). After resizing the image to 128 by 32, how this QGraphicsRectItem can be redrawn with proper co-ordinates.

The image is first resized, and then the graphicsRectItem to be added.

How a qrect can be mapped with respect to the image resized?

raven-worx

@sayan275 how do you add the rect item exactly?
You could add the rect item as a child of the image item for example and simply resize it to the parent boundingRect

sayan275

@raven-worx

I tried the following but didn't work out..

        QGraphicsPixmapItem* item = new QGraphicsPixmapItem(QPixmap::fromImage(qImage, Qt::AutoColor));
        m_ViewerScene->addItem(item);
        QGraphicsRectItem* rect = new QGraphicsRectItem(m_BoundingBox);
        m_ViewerScene->addItem(rect);
        rect->setParentItem(item);
        m_ViewerScene->update();
        //add the resized QGraphicsPixmapItem to the pixmap
        item->setPixmap( item->pixmap().scaled(QSize(128, 32),Qt::IgnoreAspectRatio, Qt::SmoothTransformation));
        qInfo()<<"Rect resize props:::"<<item->childItems()[0]->boundingRect();
        m_BoundingBox = item->childItems()[0]->boundingRect();

later I'm drawing box, on the image in an other viewer, with m_BoundingBox.

The grey area within the blue rectangle will be resized to 128 * 32, and then the red rectangle would be added on the resized image. How to get the co-ordinates of red rect on the resized image?