As part of our research in an HCI project, we need to track what users are drawing on pieces of paper in real time. Due to some requirements, we cannot replace the paper with anything digital. What we can do is tracking the user's pen movement using cameras, or use some sort of digital pen which works on paper (like Anoto or Livescribe), but with real time capabilities.

Using a camera might be more challenging due to occlusion, small size of pen and large size of the room, and so on. It seems that using a digital pen is a more viable option (I don't know of any product which offers this capability though), or maybe a completely different solution that I haven't thought of.

Any idea how can I tackle this problem? I appreciate if you can give me some pointers on technologies/tools you know which can help m

EDIT: I rephrased the question to fit the website's requirements better.

  • Does it have to be actual paper? If not a Wacom Cintiq and a good drawing application would get you a pretty close approximation.
    – Varedis
    Jul 23, 2015 at 10:19
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    @Lazarus The entire stack exchange network is not a good place to be asking product recommendations. Please refer to this: meta.stackexchange.com/questions/139511/…
    – nightning
    Jul 23, 2015 at 23:11
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    I did some basic research in this area five years ago. Most setups that had real time links between physical and digital documents, i.e. did not use Anoto or something completely different, used custom camera installations if I remember correctly. I should be able to find the .bib somewhere.
    – Crissov
    Jul 23, 2015 at 23:20
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    Did you check the Livescribe pens, though?
    – Crissov
    Jul 23, 2015 at 23:33
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    this is a valid HCI question because I'm reading it as how one can record pen movements on paper.
    – colmcq
    Jul 24, 2015 at 14:14

4 Answers 4


Start with a glass table and place it under an overhead light. Use onion paper (or some other semitransparent paper) and regular pens/pencils. Put a digital camera under the table point up at the bottom of the paper. As the participant draws on the paper, their shadow may indeed be be captured by the camera, but the point of the writing tool, and any opaque ink that has already written will be far darker than that shadow. Now on the digial side, apply a threshold contrast filter to the digital feed to remove the shadow, leaving only the pen-tip and the ink.


You might want to consider a traditional classroom solution of using a document camera. Picture an old school overhead projector, but instead of projecting the image on the wall, it transmit digitally and you can put it up on a digital screen. Once it's in digital format, you can use any screen capture software to record this.

Yes, the writers hand will block the view of a small portion of the paper where the hand is resting, however the area where the pen touch the paper should be visible.


So I finally found a viable solution. It took some tinkering though. I used a Livescribe 3 pen in combination with an iPhone device. The digital pen can send the data in real time to the iPhone, but it has a closed platform so we cannot use the data straight out of the app. What I did was connecting the Livescribe iOS App to Evernote, as it will send auto updates to Evernote every minute or so. Then I use Evernote with the same login on a Windows machine and sync it every minute. The updates are not that fast, but it is the best solution we could get to so far.


Attach a Go Pro to the user's forehead or mounted just above and over their shoulder


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