Search PDF *annotations*

Is your feature request related to a problem? Please describe. I'm running on relatively low-spec hardware (Raspberry Pi 5 8GB), but I know that with the right programs I can easily whiz though tasks that would otherwise take much longer, and rga has been an important part of that.

PDF annotation is very important for retrieving information and relating it (eg. I often use tags). I currently use Zotero to search through all my PDF text/annotations, but it is much slower than rga as it's a cross-platform program. Only feature I'm missing from Zotero is the ability to search PDF annotations.

Describe the solution you'd like I'd love PDF annotation integration, to make the search more complete, as I noticed a key part of this project is searching across as many formats possible (even OCR for images is supported!)

Describe alternatives you've considered Here is some research into the challenge:

• https://www.google.com/search?as_q=bash+search+pdf+only+annotations&as_epq=&as_oq=&as_eq=&as_nlo=&as_nhi=&lr=&cr=&as_qdr=all&as_sitesearch=&as_occt=any&as_filetype=&tbs=
  • https://unix.stackexchange.com/questions/31521/how-to-extract-annotations-from-pdf-files
    • https://stackoverflow.com/questions/1106098/parse-annotations-from-a-pdf
      • https://superuser.com/questions/275964/print-only-the-annotations-of-a-pdf

And here is a list of programs that could come in handy for implementing it:

• Python packages
  • PyPDF2
  • poppler
• GitHub
  • https://github.com/measuresforjustice/textricator (not sure if it actually supports annotations, haven't tested it yet)
  • https://github.com/foleyj2/teaching-tools
• Linux packages
  • pdfannotextractor

Additional context My understanding is that PDF annotations are a standard, so the app used shouldn't be a problem.

Thank you for having a look at this! I'll likely test a lot of the programs I've listed and give some feedback, and I'm happy to test others as well.