Most consumers feed the pixmaps into a QIcon, pulling out pixmaps of sizes 32, 64, 128, 256, 512, so consumers of that QIcon will not see low-resolution pixmaps for the common sizes like 64x64. However if someone uses standardPixmap directly, or request an icon with size 512x512, we won't have a high-DPI pixmap. Unlike QStyle::standardPixmap we don't have a QWidget/QWindow argument we can use to resolve the target DPR, so we have to assume the pixmap can be used anywhere, and use the highest DPR we've seen so far, via QGuiApplication::devicePixelRatio(). Change-Id: I3f41299b180f9361e3c7b1cd1f9bf4b1d00344da Reviewed-by: Volker Hilsheimer <volker.hilsheimer@qt.io>