thumbnail for .tiff file

[yagmur]

Hello,
i have installed coppermine and i'd like to upload in my gallery some .tiff files (i have to keep this type).
I added in the "allowed_doc_types" the .tiff type and finally i can upload tiff files.
The problem is that  every tiff file's thumbnail has the same generic image and i can open it only with an image editor.
I installed and configured imageMagick  and it works,independently, very well: i can transform a tiff file to a jpg file, but i can't have the right thumbnails in my gallery.

Could someone help me please?

Thank you in advance.

[Αndré]

http://forum.coppermine-gallery.net/index.php/topic,74588.0.html