DEDA – Tracking Dots Extraction, Decoding And Anonymisation Toolkit

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DEDA is an open-source toolkit documented by TU Dresden researchers for extracting and analyzing printer tracking dots, and for masking them in scanned or print-ready documents. Its documentation describes limits tied to print type, scan quality and page content; it does not establish that the software works with every printer or removes every trace.

The DEDA toolkit gives researchers and other users software to extract and decode tracking dots from some printed documents and to mask those dots before printing, according to the project’s GitHub documentation. The project addresses a privacy issue: the small yellow marks used by many commercial color laser printers can encode information about a printer or printout, including, in some cases, a device serial number.

DEDA stands for Tracking Dots Extraction, Decoding and Anonymisation. Its documentation describes several uses: parsing tracking data from a scan, comparing prints, extracting unfamiliar dot patterns for analysis, creating a dot matrix, and anonymising a scanned image or a document prepared for printing. Users can install the software through PyPI or from the project directory, and the documentation also describes a graphical interface.

For decoding, the project recommends a lossless scan, such as PNG, at 300 dpi, with neutral contrast. The command-line parser may read and sometimes decode the data. A separate comparison command can help identify a print that differs from others in a set. The documentation cautions that new patterns may not be recognised automatically, in which case users can extract the dots for further study.

The print-ready masking workflow is more involved. Users print a calibration page without page margins, scan it at 300 dpi, and use the scan to generate a printer-specific mask. They then apply that mask to a PDF. The project advises checking a masked page under a microscope to see whether the mask covers the printer’s dots. Its documentation says that the optional Wand package is needed to mask tracking dots over white or light-colored areas in graphics. It also describes a separate cleaning command that mostly removes tracking data from a scanned image.

How the Toolkit Addresses Print Privacy

Tracking dots can connect a physical printout to information about the device that produced it. That can help forensic analysis, but the same identifying features can raise privacy concerns when documents circulate beyond their intended audience. DEDA puts analysis and masking in one toolkit, giving users a way to inspect these marks and attempt to reduce their presence in a document prepared for printing.

The project’s own instructions show why this is a specialized process rather than a universal privacy switch. Masking depends on a calibration scan of the printer, correct alignment, and checking the result. The advice to inspect a page under a microscope signals that users should verify coverage on their own equipment. The documentation describes a tool and workflow; it does not report that every printer can be identified, or that every masked print is free of tracking information.

For investigators, the extraction and comparison functions offer a way to examine patterns that may otherwise be hard to see. For people preparing sensitive documents, the anonymisation features may help address one source of identifying information in color laser output. The practical value depends on the printer, document, scan and quality of the masking process.

Research Behind the DEDA Project

The project asks users to cite a paper by Timo Richter, Stephan Escher, Dagmar Schönfeld and Thorsten Strufe, published in 2018 in the proceedings of the ACM Workshop on Information Hiding and Multimedia Security. The paper is titled “Forensic Analysis and Anonymisation of Printed Documents.” The supplied source describes the software alongside that research citation, but does not provide a newer publication date, release announcement, or version history.

The documentation says tracking dots—also called yellow dots—are systematic marks integrated into almost every commercial color laser printer. It says these marks can encode information about the printer and/or printout. That description is the project’s account of the technology; the material supplied here does not list supported printer models or provide independent measurements of how often particular devices encode specific data.

DEDA’s troubleshooting notes also set boundaries around what users may find. Monochrome pages and inkjet prints might not contain these dots. A scanner may fail to capture them if its settings remove paper texture or threshold the marks away. The project further notes that ImageMagick security settings can block PDF processing in the optional image-handling setup.

““This process is integrated in almost every commercial colour laser printer.””

— DEDA project documentation

Limits of Detection and Masking

The documentation does not identify which printer models DEDA can decode or mask, or how reliably it works across different devices. It says tracking data can “sometimes” be decoded and that unfamiliar patterns may not be recognised by the parser. It also warns that print type, scan settings and contrast affect whether dots can be detected.

The source does not quantify how much information remains after the scanned-image cleaning function or after a masked PDF is printed. It gives a visual inspection step but no reported success rate or independent evaluation in the material provided. It is also unclear from the supplied documentation when the project was last updated or which software versions are currently maintained.

Steps for Users Evaluating DEDA

Anyone assessing the toolkit can start with the project’s installation and scan guidance, then test its parsing or masking workflow on the printer and document type they intend to use. The documentation recommends lossless scans at 300 dpi and, for print-ready masking, a calibration scan made from the specific printer. It also instructs users to inspect a masked print under a microscope.

The supplied source does not announce a scheduled release, upcoming feature, or further research milestone. Until the project publishes additional compatibility or evaluation details, users will need to treat results as device- and workflow-dependent and verify them directly.

Key Questions

What does DEDA do?

DEDA is software for extracting and sometimes decoding printer tracking dots, comparing prints, and masking dots in scanned images or print-ready PDFs.

Which printers may have tracking dots?

The project says the marks are integrated into almost every commercial color laser printer. It cautions that monochrome pages and inkjet prints might not contain them.

Does DEDA guarantee an anonymous printout?

No such guarantee appears in the supplied documentation. It describes masking steps and recommends checking the printed result under a microscope; it does not claim that all identifying information is removed.

What scan settings does the project recommend?

For decoding, DEDA recommends a lossless image format, such as PNG, at 300 dpi, with neutral contrast. Scanner settings should preserve the paper texture and tracking dots.

Source: hn