QPixmap::fromImage() vs QPixmap::toImage()

[JonB]

I have to read .png (possibly others, but maybe only these) files from disk. I will need a QPixmap from that (for QGraphicsPixmapItem) for use in the application. But I (the end user) will also potentially be manipulating the image in code so I want to keep them around as QImages (from which I will produce a new QPixmap) as well.

When reading the file initially, does it make any difference whether I do:

QPixmap::load();
QPixmap::toImage();

versus

QImage::load();
QPixmap::fromImage();

? I know little about images. Is either direction (a) slower than the other or (b) loses some information in the original .png file?

[Christian Ehrlicher]

An image from a file/buffer is read by QImageReader, therefore into a QImage. Then you can convert it to a QPixmap. On windows and afair on linux there is no real conversation between QImage and QPixmap needed though.

[JonB]

@Christian-Ehrlicher said in QPixmap::fromImage() vs QPixmap::toImage():

An image from a file/buffer is read by QImageReader, therefore into a QImage.

Perfect, thanks!