XnView Software

In XnView MP 0.99.7 (and older) you can enlarge thumbnails by selecting "View >> Thumbnails size".

I'd find it very convenient and intuitive if you could zoom thumbnails using Ctrl + Mousewheel. Also, the keys "+" and "-" could be supported. Zooming in browser and image view would be similar and thus be very intuitive.

Great idea.
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I tried to zoom my directory with folders and files, but all my thumbnails on folders do not get a bigger thumbnails.
It works for files only. The only solution is to refresh the whole thumbnail collection.