Comment 3 for bug 754531

Let me try to be more understandable.

If I look at the contents of my CF card ( from a Canon400D)

/media/Card/DCIM/146CANON/IMG_0101.CR2

what i want as a final filename is

400D_C146_0101.CR2

( C is an arbitary letter I'd manually change when I reset the view counter counter in my 400D. )

the $filenumber of exiftool gives me 146-0101.CR2 which is close to what I need

see in the DCIM spec ( http://en.wikipedia.org/wiki/Design_rule_for_Camera_File_system#Directory_and_file_structure)
for more details about de structure of the DCIM structure.

The advantage of the $filenumber exif field is that it does not depend on the parent directory but only uses info already in the picture

Sorry for the noise but english is not my mother tongue