
Instead of just pre-loading the image(s) in cache, render it (not shown) and cache its display as well (when View is set to anything different from 100%).
=> the image will be displayed immediately, without having to calculate anything, and it should not take too much memory.
Moreover, when the image is loaded, it should be turned at first - based on the EXIF (if applicable) - before being cached, in order to avoid this additionnal delay for display.
Olivier