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January 4, 2021 18:07
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Save peci1/67bc29310fd4208312222c2de97ba0eb to your computer and use it in GitHub Desktop.
Anonymize a PDF document with comments so that both document metadata and comment author data do not disclose who the author is.
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| qpdf --qdf --object-streams=disable $1 $1.tmp # uncompress /FlateDecode sections | |
| perl -pe 's/(?<=\/T \()(.*?)(?=\))/ "x" x length($1) /e' $1.tmp > $1.tmp2 # remove /T commands containing author name in comments | |
| qpdf --compress-streams=y $1.tmp2 $1.tmp3 # recompress streams | |
| qpdf --empty --pages $1.tmp3 1-z -- $1.anonymous.pdf # remove document metadata (this also removes whole comments) | |
| rm $1.tmp* # cleanup |
You can also want to search the document for instances of your name. It doesn't have to be encoded in ASCII only. Here's an example of finding a hex version of your name in the document. You can then use sed to replace all letters in your name with a character, e.g. x.
grep $(echo -n "Martin Pecka" | xxd -ps) $1.tmp
Or a 00-prefixed hex string:
grep $(echo -n "Martin Pecka" | xxd -ps | sed -r 's/.{2}/00&/g') $1.tmp
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Super helpful, thanks!