On 9/21/07, Luca De Santis <[EMAIL PROTECTED]> wrote: > The JPEG standard doesn't cover a way to encode the resolution of a > file but the JFIF extension does. For a quick and useful introduction > to these concepts you can visit the Wikipedia page > http://en.wikipedia.org/wiki/JFIF > Here you can find a very useful table with the byte map of a JFIF file.
My understanding is that EXIF has now pretty much replaced the JFIF resolution system. http://en.wikipedia.org/wiki/Exif I think most image processing systems use EXIF to put DPI information into JPEG images. PIL will read EXIF tags from a JPEG image, but (as far as I can see) will not write tags back again. Googling for "PIL EXIF" seems uncertain anyway. John _______________________________________________ Image-SIG maillist - Image-SIG@python.org http://mail.python.org/mailman/listinfo/image-sig
