change uploaded file name

[pyro]

by default is uploades file name orig_IMGname.jpg - is there a way to change whatever this orig_? i want that fullsize picture names are big_IMGname.jpg

[Nibbler]

Is this a modpack question?

[pyro]

i dont find modpack for this so i need modifi core files

[Nibbler]

Coppermine doesn't use a prefix for fullsize files, only thumbnails (thumb_) and resized images (normal_).