Ich bin Deborah.
Schaut euch meine Arbeiten
an oder lest meinen Blog.

How to print an invisible IR marker using a standard printer

Leider ist der Eintrag nur auf Amerikanisches Englisch verfügbar. Der Inhalt wird unten in einer verfügbaren Sprache angezeigt. Klicken Sie auf den Link, um die aktuelle Sprache zu ändern.

Deborah Schmidt, Johannes Fritzsche

How do we create markers that are visible to cameras, but not to our eyes?

Tracking markers (e.g. QR Codes) are a common tool to create mixed reality applications. They look ugly, they can’t be too small for successful detection. In our case, we wanted to use them to recognize book pages and project onto them, but the projection on top of the blunt black pattern would not give the content justice.

A common technique to recognize something visually outside of the humanly receptive spectrum is the usage of Near-Infrared (NIR) cameras. There are high quality / high price solutions to print the markers with the same special ink used on paper money to create invisible watermarks. We experimented a lot to find a cheaper DIY solution and here it is!

Build a Near-Infrared receptive camera

First, we need a Near-Infrared receptive camera. You can specifically buy one or you can also modify a cheap webcam by removing the IR filter and adding a visible light filter (e.g. dia film). Here is a guide.

Material and color experiments

Experiment with the camera. What do you see? How do different colors look like on the material you want to use?

Since we wanted to print markers, we used a color printer with black cartridge as well as color cartridges and took standard printer test pages (this one from Ubuntu was perfect) to get a feeling for what the IR cam can detect. We realized that what we printed with the black ink was also visible in NIR, but stayed invisible to the camera if printed using the color cartridges.

This marker was printed in a middle tone grey with the black ink and inserted a second time into the printer to print a colored motive on top of it. You can hardly see the marker and utilize any fitting motive to cover it.

For our scenario we needed a plane, light, non-distracting surface. It also had to be something that we could mass print. Therefore we printed the markers in the lightest grey that was still detectable using the black ink, and printed the remaining white quads (the negative space of the marker) in a similar grey by mixing the color inks in a similar amount.

Marker image creation

In Inkscape there is a simple way to achieve that: Assign the color using the CMYK color picker and make sure that C, M and Y are zero. The printer will use the black ink. Add a small amount to Cyan, Magenta or Yellow and the printer will solely use the color cartridges, but create a similar grey tone. This way, we did not have to insert the page twice into the printer. Of course, if this works depends on the driver and the system – experiment.


We were able to print a 100 page book with markers of the size of the full page using our home printer. We were able to project onto the markers without anyone noticing them (they were still recognizable though).

Have a look at the final project video to see the result:

Sag etwas

Deine email-Adresse wird nicht veröffentlicht.

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>

Artikel zum Thema "Blog":

How to print an invisible IR marker using a standard printerQuick, Draw! Generierte Zeichnungen, Teil 2(English) The Art of CodingImperfekte MandalasHerbstblätterFarbexplosion #25 Jahre KAZOOSH!FarbexplosionUbuntu 15.10, MongoDB und node.jsSpeed of Fencing Remixgit cheat sheetFraktaleofxSortableListHäkeln: Haarband mit JeansknopfWandmalen zu Marias GeburtstagLinux / Ubuntu + Serato Vinyl Control System + Pure DataWicket-Bootstrap – Navbar und Pageparameters – aktives Item setzenLinux Console MerkzettelCrawling Traces @Deutscher Multimediapreis mb21Crawling Traces History Viewernew.livestream.com unter Ubuntu mit VLC abspielenCrawling Traces at Hechtfest / hechtgruenLinksammlung: Datensicherheit, soziale Netzwerke und sicheres MailingFix: VMware Player Crash unter Ubuntu 13.04Xubuntu: Wenn Dockbarx Thunar oder das Terminal nicht startet.Ubuntu 12.10, libwebsockets and OFSetting up Meteor with Ubuntu 12.10 on an NTFS share partitionWebauftritt: KAZOOSH!Zwischenstand IsolinienDas Scheunentor wird buntSkype auf Ubuntu 10.10 oder 11.04 64bitElitebook 8440p vs UbuntuKryptografie & Datensicherheit – NotizenRandom Compilation IIRandom Compilation IAll You Can Eat in DresdenWebauftritt: ESE 2010