Master's Thesis - Studierstube Augmented Reality Project - Graz ...

4.4 Visualization Framework
datasets, the required features to support them - such as slice navigation, zooming,
panning, window / level adjustment - are implemented as well. Medical image processing,
respectively the administration of morphological data is done with the Insight
Segmentation and Registration Toolkit (ITK) [ITK2006] in the background. Figure 4.7
illustrates the isolated iMEDgine viewer GUI with two anatomical example datasets.
Each view renders a scene-graph implemented with Coin [SystemsInMotion2007] whose
main structure is shown in figure 4.6.
Figure 4.6: The basic scene-graph of iMedgine views. Below the ”Dynamic Separator”
all the image related nodes (plane, texture, volume rendering...) can be added. The
”Static Separator” allows to add an additional information overlay like slice counters,
cross hair, DICOM-entries etc. Image from [Streit2006].
In this thesis this basic scene graph is extended with special-purpose separator
nodes such as the ”Flow-Volume Separator”. This allows to separate the pure grayvalued
image data visualization from overlaid and embedded flow visualizations. These
separators combine both Cash-Flow scene-graphs (see section 4.4.1.3) and further flow
visualization nodes, i.e. hardware accelerated ones.
The use of design patterns and the well known library Qt [Trolltech2007] allows
to define new datasets and corresponding views and view controlling widgets fast and
comfortably. Using Coin3D scene graphs eases the development of new views through
the possible scripting of a good portion of new code.
Augmenting the iMEDgine viewer with new dataset classes (DICOM and 4D-Flow
Toolbox intermediate file) allowes to handle the 4D-Flow intermediate result file which
is described in section 4.2. A new correlated configuration widget enables the user to
choose the current temporal position and some other time-depenent adjustments for
each dataset for some views. Others can be controlled directly inside the render area.
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