Suggestions for unredacting badly redacted documents? – Digitalmunition




Home Forums Suggestions for unredacting badly redacted documents?

This topic contains 1 reply, has 2 voices, and was last updated by  fleeb_ 2 weeks, 3 days ago.

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  • #378889

    anonymous
    Participant

    I guess this isn’t conventional hacking; it’s infosec and it’s computer based, but involves scanned redacted documents.

    The documents I have were FOIA’ed by someone else more than two decades ago and have been online since then. I have trouble believing I’m the first to have spotted this mistake but some searching returned no hits.

    What has happened is the redactor has cut out little squares of paper to place over the redacted sections of the document and then scanned it. What they were supposed to then do was fiddle with the contrast to make sure nothing bleeds through (i.e. make light greys white and dark greys blacker). Historically this would be done with a photocopier but I assume around this time they may have been switching to digital someone made mistake because only a quarter of the pages part way through are like this.

    I noticed this mistake last night while looking through a pile of FOIA’ed documents from someone else’s online archive and have tried in GIMP to fiddle with the contrast to make things stand out to some partial success. I know very little about image processing though so I was hoping someone might be able to point me towards some better tools or better technique.

    The document includes both images and text.

  • #378891

    Ixta44

    Curves image tool. If you know how to use it

  • #378890

    fleeb_

    You could try to crank up the contrast and isolate just those letters. Turn it up so it’s just black and white. If there is grey left, make it greyscale. Maybe try to smooth out any speckling, and either read the characters, or run them through some online OCR (optical character recognition) online if there are reams of pages.

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