Separate images for thumbnails and big size picture.

Hello everybody!
I’m looking for an oportunity to upload separate images for thumbnails and full-size pictures.
(or enable transforming thumbnails to B/W from colour pictures with script)

I’ve scanned through forums, but didn’t check any info.

Does anybody have the same thing to solve? ))

Thank you very much.

Not possible.. You can change the thumbnail picture files after upload though.. could do a script that does the necessary changes to the thumbnails after upload..