Information Technology Reference
In-Depth Information
nearly everywhere. In this case, pen data is streamed to a personal mobile device
that acts as an information hub and decides how to distribute pen data further to
other computing devices over a network connection. Letras also supports different
configurations; for instance the pen can be coupled with a PC.
Letras has a modular architecture. It relies on a distributed processing pipeline
for pen data. Different processing stages are decoupled using generic interfaces. The
first processing stage, the driver stage, connects to one or several Anoto pens. This
includes simultaneous connection to different pen models. A next processing stage
provides for abstracting from raw pen coordinates to higher-level interactive areas.
This is similar to the interactive areas of the Anoto SDK, but with a distributed
lookup of area definitions across multiple issuing organizations, allowing to dis-
tribute interactive paper material such as leaflets. Further processing stages support
semantic processing, e.g. handwriting recognition, and application-level processing,
e.g. rendering the ink traces. Application developers can develop additional process-
ing stages and flexibly deploy processing stages to different computers and devices.
While the first processing stage is typically deployed on a computing device that
is used by end-users (e.g. the mobile phone, the tablet or the PC), the application
developer can decide where to deploy other stages. For instance, handwriting recog-
nition might be performed on a server. For rendering, the system might detect which
computing devices in the room feature a large screen and dynamically deploy the
rendering stage on one of these devices. The individual stages are interconnected
with the MundoCore middleware [3]. This supports the dynamic configuration of
the computing environment. A drawback of Letras is that it currently does not pro-
vide a print toolkit. For adding the Anoto pattern to documents, the developer must
use one of the Anoto SDKs.
Letras is developed in Java and contains some native components for Mac OS X,
Windows and Linux. It provides native support for streaming pen data to Android
devices. It currently supports Anoto ADP-301, Anoto DP-201, Logitech/Destiny io2
and Nokia SU-1B.
Livescribe SDK
Livescribe offers an SDK for their Livescribe pens.
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It can be downloaded and used
free of charge. It follows a different approach than the frameworks presented above.
In contrast to standard Anoto pens which do only capture pen data and transfer it
to a computer, a Livescribe pen has a processing unit that can execute custom code.
Livescribe applications consist of a paper product and a penlet. A penlet is a piece
of software that is executed directly on the pen. This enables to develop applications
that react on user input in real-time without requiring a streaming connection to a
second computer device which handles the interpretation. Furthermore, a specific
Desktop SDK offers support for developing desktop applications that access pen
data (this is similar to the standard way of Anoto-based applications).
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http://www.livescribe.com
