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BishopFox
unredacter
TypeScript2022–2025
BishopFox / unredacter

unredacter

Never ever ever use pixelation as a redaction technique

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7Distinct people
7Mentions
0Explicit recommenders
8.4KGitHub stars
REPOSITORY AT A GLANCE

What to know before exploring

What it is

Never ever ever use pixelation as a redaction technique

GitHub

Where it is used

No documented product use has been verified yet.

What people are saying

No recommendation phrase was found in the indexed comments.

No classified warning is attached to this page. Read the discussions before treating silence as approval.

Also in these discussions

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This week on Hacker News

Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.

No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.

Mentions over time

HN mentions by year7 dated mentions

Observed mentions: 2022-06-01 13:49:32 UTC to 2025-12-28 18:47:03 UTC.

01232022-01-01 00:00:00 UTC to 2023-01-01 00:00:00 UTC (exclusive): 3 mentions; 1 submissions, 2 comments20222023-01-01 00:00:00 UTC to 2024-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments20232024-01-01 00:00:00 UTC to 2025-01-01 00:00:00 UTC (exclusive): 0 mentions; 0 submissions, 0 comments2025-01-01 00:00:00 UTC to 2026-01-01 00:00:00 UTC (exclusive): 2 mentions; 0 submissions, 2 comments2025

Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.

View mention counts and date ranges
UTC ranges include their start and exclude their end. Select a period to filter the source evidence.
PeriodStart (UTC)End (exclusive, UTC)MentionsSubmissionsComments
20222022-01-01 00:00:00 UTC2023-01-01 00:00:00 UTC312
20232023-01-01 00:00:00 UTC2024-01-01 00:00:00 UTC202
20242024-01-01 00:00:00 UTC2025-01-01 00:00:00 UTC000
20252025-01-01 00:00:00 UTC2026-01-01 00:00:00 UTC202

What Hacker News says

7 sources
alright2565·Dec 28, 2025
The Flameshot screenshot tool uses an interesting variant of pixelation that does protect the text from unredaction: https://github.com/flameshot-org/flameshot/commit/533a1b7d55... > Since pixelation does not protect the contents of the pixelated area (see e.g. https://github.com/bishopfox/unredacter), _pseudo-pixelation_ is used: > Only colors from the fringe of the selected area are used to generate a pixelation-like effect. The interior of the selected area is not used as an input at all and hence can not be recovered. The edges of the pixelated area are used the generate a color palette, and then each pixel is generated by randomly sampling from that pallete's gradient.
In Never Use Pixelation to Hide Sensitive Text (2014)
zamadatix·Mar 19, 2023
> You can use the well known approach like https://github.com/bishopfox/unredacter If it's so easy and already done why not show it actually reconstructing real examples like that page. The reality is there is no existing well known approach for recovering data in the exact way you laid out. Similar approaches sure but they rely on different data sources (such as downsampled versions of text) instead of artifacts. That it is feasible in the easy case does not mean it is feasible in the hard case, why should the two be expected to hold the exact same amount of information about the source? Even if they do the method of reconstruction will surely be different. > I am just showing that jpg compression cast a digital shadow on itself that can be outside of the cropped area, which many people find unintuitive. That I agree 100%, and it's a gre
Read the rest
at thing to show, it's just a bit overreaching to then name that "jpguncrop" with a description referring to aCropalypse instead. Maybe it could lead to something like that but what's in the repository does not match the name or description. > Matching the shape of this digital shadow (which is not very small (all the highlighted pixel region contain some info) ), combined with an educated prior on the missing portion (that must provide a way to represent the hidden portion in less bits than you can get from the shape of the shadow) , can help you recover the data. Great, you have a theory - demonstrate! I'll be the first to comment on how clever, persevering, and well executed the work was if you post a thread showing it works. Until that point though it isn't so just because you think it would work. Here is a great test case https://i.imgur.com/sAEpfQ6.jpg. The font size should be small enough that data leaks out of the obfuscated area from the characters. I'm optimistic this blind reconstruction case is feasible given the additional constraints compared to the circle test but it would probably take a decent chunk of new work.
In Exploiting aCropalypse: Recovering truncated PNGs
GistNoesis·Mar 19, 2023
You can use the well known approach like https://github.com/bishopfox/unredacter I am just showing that jpg compression cast a digital shadow on itself that can be outside of the cropped area, which many people find unintuitive. Matching the shape of this digital shadow (which is not very small (all the highlighted pixel region contain some info) ), combined with an educated prior on the missing portion (that must provide a way to represent the hidden portion in less bits than you can get from the shape of the shadow) , can help you recover the data.
In Exploiting aCropalypse: Recovering truncated PNGs

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