These two days, I studied how to export PDF annotations. Not done, roughly list some key points for your reference:

  • Adobe took the lead in developing the PDF standard, which is so old and long that it’s generally not worth looking at
  • Apple provides PDFKit; However, more than ten years did not update, the function is relatively weak
    • Core, Cmap errors occur when parsing annotated text, but there is nothing to set
    • In addition, WWDC 2017 released PDFKit for iOS, so I didn’t study it. I guess the focus is on display, not editing
  • For third-party PDF SDKS:
    • A few are free, or open source, most notably Skim; Unfortunately, Skim also cannot parse annotated text, especially text or fonts that are not in English
    • For the most part, commercial SDKS; The effect I can not say, because at every turn $1000 a year of authorization, can not try
  • PDF Expert is the strongest product I’ve ever tried. Of course, the price is also the most ferocious

Overall, PDF is still a small game played by a small group of players. Vested interests, a firm grip on the market; The latecomers are unlikely to come in and make a difference. Standards themselves lack the motivation to keep up with The Times. I don’t think so.

However, I did build a simple gadget based on Apple’s PDFKit that can export annotations from PDF into CSV text. Need a friend, can contact me alone.

1109-PDF annotated export, from get started to dump