Mastodawn

@djb Kudos to djb for supporting #MuPDF usage.

That said and celebrated ;), there are things that #Censor is not yet well redacting.

The upstream library #MuPDF (with its #Python bindings in #PyMuPDF) supports by default only redaction of text, vector graphics and images. Testing on a variety of PDF files (thanks to #pypdf, #qpdf, #ghostscript, and their issue reporters, as well as @pdfarranger for their hint) let me discover that some vector graphics are not properly redacted and an upstream issue has been reported for that.

Also, form fields (widgets), signatures and links may be incompletely redacted.

You can find an updated list of “What is redacted? What not?” here: https://codeberg.org/censor/Censor/issues/120

#pdf #redaction #security

meta: What is redacted? What not?

> **Warning** > The following description is **not** valid for Censor until version 0.4.0. I recommend to update to [version 0.5.0](https://codeberg.org/censor/Censor/releases/tag/v0.5.0) for secure redaction. ## Elements under redaction rectangles - [x] Text: - characters are removed when ...

Codeberg.org

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Robert Wolff 2d ago

“Better safe than sorry”

For release 0.5.0 of #Censor, a lot of work went into improving the security of PDF redaction.

PDF documents are tricky, and irrevocably removing elements from them is even more. With this release, before saving a redacted document, garbage is now properly collected and documents are sanitized, which means that metadata, page thumbnails, etc. are removed.

Also, vector graphics are now removed with a more strict option when they overlap with redaction rectangles. On top of that, I added redaction of PDF annotations.

The user interface was refreshed: with undo and redo buttons in the toolbar and improved document saving experience. Drawing rectangles is now indicated by a crosshair cursor.

Thanks to the translators, you may now talk also Czech with Censor!

Get it from @flathub: https://flathub.org/apps/page.codeberg.censor.Censor, or contribute on @Codeberg: https://codeberg.org/censor/Censor

#censorship #redaction #PDF #Codeberg #Flatpak #Flathub #GNOME #python #MuPDF #PyMuPDF #linux

Install Censor on Linux | Flathub

Redact PDF documents

Bruce Simpson, Ph.D.Mar 10

#Desktop #Linux Kryptonite detected: None of the main Linux #PDF readers support the #MuPDF rendering engine. In 2026. C'mon. Get real. #SumatraPDF would be the answer, but the author declines to port it as it's too inherently tied to #Windows itself. KDE never incorporated the #Okular backend for #MuPDF and it's been forked on GitHub nearly 12 times. I tried #Sioyek but I found the UI was too minimalist. #EVince is still stuck using #Poppler. https://www.sumatrapdfreader.org/

Free PDF Reader - Sumatra PDF

Sumatra PDF reader and viewer for Windows

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Robert Wolff Feb 28

“A historic moment for Censor”

#Censor – the PDF redaction tool for the @gnome desktop – comes now with a new edit history. It allows you to undo and redo redactions using the right-click context menu or keyboard shortcuts. Also, a bug that prevented repeated saving to the same file path was fixed.

Get the new version from @flathub: https://flathub.org/apps/page.codeberg.censor.Censor, and find it on @Codeberg: https://codeberg.org/censor/Censor/releases/tag/v0.4.0

You may now talk Chinese, Dutch, English, Estonian, Finnish, French, German, Italian, and Vietnamese with Censor (thanks a lot to the translators!). If your language is missing from this list I invite you to contribute at Codeberg Translate: https://translate.codeberg.org/engage/censor

#censorship #redaction #PDF #Codeberg #Flatpak #Flathub #GNOME #python #MuPDF #PyMuPDF #Linux

Install Censor on Linux | Flathub

Redact PDF documents

RedPacket Security Feb 11

CVE Alert: CVE-2025-15569 - Artifex - MuPDF - https://www.redpacketsecurity.com/cve-alert-cve-2025-15569-artifex-mupdf/

#OSINT #ThreatIntel #CyberSecurity #cve-2025-15569 #artifex #mupdf

CVE Alert: CVE-2025-15569 - Artifex - MuPDF - RedPacket Security

A flaw has been found in Artifex MuPDF up to 1.26.1 on Windows. The impacted element is the function get_system_dpi of the file platform/x11/win_main.c. This

RedPacket Security

R.L. Dane

🍵

Feb 8

Mmmmm, naaaah, I'll just use #zathura or #MuPDF, thanks.

rld@Intrepid:~$ doas pkg install calibre
doas (rld@Intrepid) password: 
Updating FreeBSD repository catalogue...
FreeBSD repository is up to date.
Updating FreeBSD-kmods repository catalogue...
FreeBSD-kmods repository is up to date.
All repositories are up to date.
The following 62 package(s) will be affected (of 0 checked):

New packages to be INSTALLED:
	MathJax3: 3.2.2 [FreeBSD]
	assimp: 6.0.2 [FreeBSD]
	calibre: 8.16.2_1 [FreeBSD]
	gstreamer1-plugins-good: 1.26.10 [FreeBSD]
	gstreamer1-plugins-pulse: 1.26.10 [FreeBSD]
	gstreamer1-plugins-ugly: 1.26.10 [FreeBSD]
	hyphen: 2.8.8 [FreeBSD]
	liberation-fonts-ttf: 2.1.5,2 [FreeBSD]
	libmtp: 1.1.22 [FreeBSD]
	pcsc-lite: 2.3.3_1,2 [FreeBSD]
	podofo: 0.10.4_2 [FreeBSD]
	(((39 python packages)))
	(((12 qt6 packages)))

Number of packages to be installed: 62

The process will require 269 MiB more space.
65 MiB to be downloaded.

Proceed with this action? [y/N]: n
rld@Intrepid:~$

Hacker News Dec 30

Zpdf: PDF text extraction in Zig – 5x faster than MuPDF

https://github.com/Lulzx/zpdf

#HackerNews #Zpdf #PDF #text #extraction #Zig #MuPDF #faster #technology

Robert Wolff Dec 21

Censor, a new document redaction tool, is there!

It allows to draw black rectangles on PDF documents and to permanently remove the text and images below. Find it on @Codeberg: https://codeberg.org/censor/Censor, get it from @flathub: https://flathub.org/apps/page.codeberg.censor.Censor, or translate it on Codeberg Translate: https://translate.codeberg.org/engage/censor!

It is a free and open-source graphical user interface (GUI) for #Linux and the #GNOME desktop, and uses the #MuPDF library with its #python bindings from the #PyMuPDF module.

#censorship #redaction #PDF #Codeberg #Flatpak #Flathub

Censor

PDF Document Redaction for the GNOME Desktop

Codeberg.org

gdorn Oct 27

ETA: Okular + MuPDF backend seems the best answer for Linux.

Original Gripe:
Why is there no such thing as a pdf viewer capable of flipping through a game book (e.g. the OSE bundle on DTRPG) as fast as a physical book?

I mean, startup time is one thing; rendering a book with all of the art and fonts and backgrounds, sure, take a minute to do so, especially with the really dense books with tons of complex layout.

But why does every pdf viewer seem to throw out the rendered pages and only keep a handful open at a time? I have 64GB of RAM, I can fit the entire book in memory; heck, it could rasterize the entire thing to .bmp and store a thousand copies of it, easily, so why do they all prefer low memory usage to speed?

ETA: In the tradition of complaining about something followed by finally getting a lucky search result, I immediately found MuPDF, which is very fast engine but not really usable as an app itself, but is used as a backend by several other apps. One of those apps, Okular, also has memory configuration options, one of which is "greedy" which will use up to half your RAM to keep rendered pages in.

So #Okular + #MuPDF appears to solve my problem, finally, after years of griping about it.

Ditch evince!

#pdf #pdfviewer