Image scaling is done by external libraries such as Qt, so thumbnailer can't really do much to make it faster. I'd imagine those libraries are already relatively fine tuned.
The image sizes that the thumbnailer stores come from the freedesktop.org thumbnailing standard. It has not changed in years and is not expected to. So the simplest thing is to just grab the size that is the fastest.
Image scaling is done by external libraries such as Qt, so thumbnailer can't really do much to make it faster. I'd imagine those libraries are already relatively fine tuned.
The image sizes that the thumbnailer stores come from the freedesktop.org thumbnailing standard. It has not changed in years and is not expected to. So the simplest thing is to just grab the size that is the fastest.