rbl:
I took a closer look now and this can be achieved quite easily:
Open file /forums/includes/functions_gallery_imageedit.php
Inside this file somewhere around line 246 look for this
Code:
Content visible to verified customers only.
Replace with this:
Code:
Content visible to verified customers only.
Save your file and throw some weird image names to test it. It replaces every character that is not alphanumeric, dash, underscore or the dot, with one underscore.
Test it and let me know. I tried it with an imagename like this:
Az%20ñame cósa_ivclrd01.jpg
and the result was:
az_20_ame_c_sa_ivclrd01.jpg