Prefetching images in standalone viewer

I would appreciate something along these lines. (Unsure if it has been done already.)

Preparing decoded versions at different zoom levels would be nice too - caching them on memory only, for as long as the source folder was open.

Would not mind to have it restricted to NVIDIA GPU's, via some SDK like this.

As a consumer, JPEG support would be enough for me. Don't know if the photographer user base would want it too.

This was one of the new additions to the viewer in Opus 12.

Is it limited to fetching the compressed image or does it decodes it too?

It decodes it, but JPEG decoding is normally very fast anyway.

It does not scale it until it is displayed. (You can use 100% zoom to see if that is a factor.)

Guess that is it then. I changed from "reset zoom level for each picture to: fit to page" to "original size" and going back/forth was faster, practically instantly. Zooming still takes a while.

It would be great if multiple scaled images were prepared in advance.

Also, the caching seems to apply only to the next/previous. I use Show VIEWERCMD=goto,+10 for faster navigation and I am planning to write a script to jump to the first image of the next/previous folder, so a more aggressive caching would be great.