bruns added a comment.
Unfortunately, the QImage**Reader** documentation is not very clear about the effect of `setQuality(..)`. There is a reference to `https://doc.qt.io/qt-5/qimagereader.html#setScaledSize`, and that in turn has a reference to `QImage::scale()` (which no longer exists in Qt5) and `Qt::SmoothScaling`. Looking a the images (which lack any legend, so are hard to interpret), a quality of 0 seems to trigger something like nearest neighbor scaling. For very large images, a fast approximation may still be better. REPOSITORY R320 KIO Extras REVISION DETAIL https://phabricator.kde.org/D26648 To: chroniceel, broulik, #frameworks, #vdg Cc: bruns, ngraham, kde-frameworks-devel, kfm-devel, pberestov, iasensio, fprice, LeGast00n, MrPepe, fbampaloukas, alexde, GB_2, Codezela, feverfew, meven, michaelh, spoorun, navarromorales, firef, andrebarros, emmanuelp, mikesomov
