1.)
My Mistake, Exiftrans is just a program to edit these tags for jpg. the program exiv2 can edit the tags also for tiff. th tags are called "exif", maybe this can help:
http://www.sno.phy.queensu.ca/~phil/exi ... /EXIF.html i edit the tags with this command line
exiv2 -k -M"set Exif.Image.Orientation 3" %F
this rotates the image to 180 degrees. exiv2 (and exiftrans for jpg, of course) don't change the image, they only edit a tag and all programs that can read out the tag display it in the right way - rotated to 180 degrees. i think convert ignores the tag.
2.)
This works, thanks. but the resulting tiff files doesn't have the same size as the tiff files i've created from the pdf with the windows tool pdf xchange view (here i can set up output as uncompressed tiff). the files created by pdf xchange view are much bigger