Earlier quoted context omitted.
It's not that you can unredact them from scratch (you could never get the blue circle back from this software). It's that you can tell which of the redacted images is which of the origin images. Investigative teams often find themselves in a situation where they have all four images, but need to work out which redacted files are which of the origins. Take for example, where headed paper is otherwise entirely redacted…
Ok thanks. That sounds reasonable. >... and therefore you can unredact them from that readme is just not true then I guess?
I think the word should be "redact".