Quote:
Originally Posted by ardeegee
I think I know why my PDF, at least, has conversion problems. It has a font called "Charis SIL" embedded, and is something called a "smart font"
Charis SIL is a TrueType font with “smart font” capabilities added using the Graphite, OpenType®, and AAT font technologies. This means that complex typographic issues such as the placement of diacritics or the formation of ligatures are handled by the font, provided you are running an application that provides an adequate level of support for one of these smart font technologies. With the old font (and its derivatives), diacritic placement was handled using non-standard character encodings that incorporated multiple versions of a diacritic as distinctly-encoded characters. |
That is interesting. I checked my 'problem' PDF to see if it matched the pattern you've identified. Sure enough, my conversion problem involves Adobe Garamond Pro, an OpenType font and therefore (I assume) one with smart font capabilities. The same PDF has a small sample of text with some of the same letter combinations, using a different font (TimesNewRoman Italic, I believe, which is a TrueType font and therefore without smart font capabilities), and this does not show a conversion problem.
But when I tried to create a new PDF using the problematic letter combinations and using these two fonts, the conversion went ok. So I'm still only able to see a problem with this one PDF file, and never with anything I create myself.
I still think it points to a problem with the (open source?) PDF library calibre is using, because it cannot convert this particular PDF file to any other format without corruption, whereas Acrobat, and Adobe's free PDF2TXT and PDF2HTML services, don't have this issue.