problem with series 60 theme studio

can i use jpeg file to creat theme and how coz i saw my friend's uncle had creat theme using picture that capture by 7610. i try to open jpeg file from my computer but it just read *tdf file. i dont have such type of file so how to convert jpeg to this kind of format? i realy want to creat theme with my picture

Well,

.TDF is not the picture file but that theme studio's raw file.

you can use jepg by selecting the bakground and then browse the photo

I want to know the exact procedure to do that along with screenshots if possible.