Geography Reference
In-Depth Information
objects of the orthophoto like sport fields, buildings and roads were coloured to
enhance them. The result was exported to a VRML file and printed on a Contex
DESIGNmate CX
TM
printer which created the 3D model like described in
Sect.
3.1
and shown in Fig.
9
(Schwarzbach et al.
2012
).
8 Internet-Based Stereo Visualisation
In 2006 a first real-time transmission of various large sets of geodata between a
university lecture hall in Dresden and a university 3D cave in the town of Trier,
530 km great circle distance from each other, took place. This can today be
realised by any private individual, thanks to adequate Internet connections.
The Spanish company Sigrid S.L. offers e.g. map server software named Ste-
reoWebMap. This software is based on OGC WMS standard and offers via internet
both vector- and raster-based air campaign data as well as airphotos. Besides
orthophotos and anaglyph images for visualisation on a standard monitor rendered
stereomates can also be requested. This type of image is meant to be used with
special stereo-hardware like stereo-projectors and can be three-dimensionally
viewed with the help of polarisation glasses. One possibility is to visualise the two
stereomates on two TFT (Thin Film Transistor) displays with identical polarisa-
tion, which reflect the images onto a semi-reflective glass in between. Therefore,
one stereomate has to be mirrored (Fig.
18
). The viewer perceives the stereoscopic
impression of the scene by using polarisation glasses (
www.StereoWebMap
;
Sanchez
2012
). Thus, this technique cannot be considered autostereoscopic, but
with an adequate true-3D display in the near future glasses-free viewing of these
geodata provided via Internet will be possible.
Buchroithner et al. (
2012
) present in their paper several ''stereoscopic 3-D
hardware and software solutions for creating and displaying online maps and
virtual globes (such as Google Earth) in 'true-3D', with costs ranging from almost
free to several thousand [sic] pounds sterling.'' Here, only a few samples will be
presented.
To create your own stereo images a free software program named StereoPhoto
Maker is available. It acts as both a stereo image editor and viewer. A further
function allows the easy change of geographical information in the metadata of the
image (
www.StereoPhotoMaker
). Another freeware stereoscopic browser is the
Stereo GE Browser (
www.StereoGEBrowser
)
. Using the free Google Earth browser
plug-in this browser shows three instances of an image: two windows show the left
and right stereomate and the third window visualises the stereo image. The user can
choose different stereo methods, such as anaglyphs or side-by-side stereograms and
set the stereo-base. An interesting tool is the StereoGIS (
www.SimWright
)
from
SimWright Inc., an analysis application. For imagery in a 3D stereo format the user
can create, edit or extract two- and three-dimensional data products as well as
DEMs from the given imagery (Buchroithner et al.
2012
).
