Comment by _flux
6 hours ago
> But anyone can visually examine this.
Can they? In principle it could be the difference between RGB 0.0,0.0,0.0 and RGB 0.004,0.0,0.0, that could be very difficult to visually see, but an algorithm could unmask the data with some correlation.
If you do it digitally and then map the material to black-and-white bitmap, then that you can actually virtually examine.
> Contrast that with a digital redation. You have to trust the tool works.
While true, I think the key problem is that the tools used were not made for digital redaction. If they were I would be quite a bit more confident that they would also work properly.
Seems like there could be a product for this domain.. And after some googling, it appears there is.
It's probably fine, but certainly better than what's being discussed ITT.
The larger point is that the "usual" redaction involves a tape pen or paint-style ink (dries opaque), IIRC, then photocopy, because the blocked out area is opaque. Scanner is probably no different than photocopy for these purposes.
> While true, I think the key problem is that the tools used were not made for digital redaction. If they were I would be quite a bit more confident that they would also work properly.
Adobe Acrobat's redaction tools regularly feature in this sort of fuck-up, and they are (at least marketed as being) designed for such use
Just scan it with black/ white setting.