possibilities

1
possibilities pitfalls of web sites for spatial
data dissemination

• Barend Köbben
• International Institute for Geo-information
  Science and Earth Observation (ITC)

2
Setting the stage

• Barend Köbben
• ltkobben_at_itc.nlgt

3
Overview

• Why use maps?
• Changing Cartography
• Why use the Web?
• WebCartography
• static view-only web-maps
• static interactive web-maps
• dynamic view-only web-maps
• dynamic interactive web-maps
• How the Web works

4
Why use graphics?

• Graphics are international
• uitgang, exit, Ausgang, sortie, uscita,
  salida,etc...

5
Why use graphics?

• Graphics are holistic
• a picture says more than a thousand words...
• First road left, then cross the railroad and
  continue until you cross the river, then the
  first right and right again on the crossroads...

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Why use maps?

• rainfall
• 12, 13, 14 september
• dirksland de bilt
  apeldoorn

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Why use maps?

• apeldoorn
• de bilt
• dirksland

8
Why use maps?

• Maps give an instant and complete overview of
  spatial phenomena

9
Developments in cartography

• 1950s first computer maps
• 1960s / 1970s automation of existing tasks
  (line drawings)
• 1980s computer-assisted map production
• 1990s full integration of maps in GI
  (scientific) visualization from supply to
  demand driven mapping Internet / Web
  environments
• 2000s location-based services in mobile
  environments

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CHANGING CARTOGRAPHY ? new kinds of maps

• Interactive maps
• Realism false realism Virtual worlds
• Depiction of movement change Animated maps
• Combining maps with other graphics, sound and
  moving images Multimedia

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Traditional vs. interactive maps

• traditional map view only map
• bitmaps (scanned images)
• interactive map (map as interface)
• clickable map leads to other (web) information
  map as menu
• interactive map (userdefined contents)
• maps on demand user defines contents and/or
  symbolisation

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Interactive maps
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Virtual worlds

• The world mapped as it is
• Perspective view (instead of orthogonal)
• Complete (not generalised)
• Realistic (not symbolised)
• Photorealism (or pseudorealism)

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Virtual Worlds

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Animated maps

• For showing dynamic phenomena
• As animated maps (movies)
• As dynamic real-time images (dynamic webpages)
• For moving through Virtual Worlds
• As animations (eg. animatedGIF, Quicktime movies)
• With interactive contents (modelled worlds, eg.
  games, VRML)

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Multimedia definition

• The combination of various media parts into a
  coherent whole
• Media parts
• maps, graphics, text, moving images, sound, text,
  etc...
• Coherent whole
• The whole is more than the sum of the parts

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CHANGING CARTOGRAPHY ? new (digital) data
dissemination

• On CDROM
• On the World Wide Web

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Why use the Web?

• WWW information is virtually platform-independent
• unrivalled in its capacity to reach many users at
  minimal costs
• easy to update frequently
• the WWW allows for a dynamic and interactive
  dissemination of spatial data ? New map types

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Disadvantages

• Potential user group is limited (though growing
  fast) and skewed (computer- literate and
  connected people)
• Difficult to charge for use
• Fast-moving
• Information is time-sensitive
• Interactivity is a must

20
World Internet users
Pie slices show regional shares of world
population. Dark wedges show Internet users
(numbers indicate Internet users as a percentage
of the total population per region). Internet
users of total world population 5.7 UNDP
2000
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Technical constraints

• Map and file size
• Screen size resolution
• Download times
• File formats
• Standardised GIF JPEG (raster), SVG (vector)
• Colour use
• Only 216 web-save colours
• ? Special map design needed

22
WebCartography

• Some examples
• Further examples
• http//kartoweb.itc.nl/webcartography/workshop
  Webcartography/index.html
• Further reading Kraak, Menno-Jan Allan Brown
  (eds) (2001)Web Cartography, developmentsand
  prospects, London and New York Taylor Francis

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WebCartography
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Static maps view only

• Existing maps (scanned)
• mainly interesting for Historical maps
• Specially designed web-maps
• eg. cartography students at ITC

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Static maps interactive interface

• Map is entrance to other (map) information
  clickable maps
• HTML clickable maps (Netherlands in provinces)
• Flash maps of Overijssel (data, magnify)
• User can change map content visualisation
• from simple layers on/off map of Overijssel
  (Flash)
• to fully interactive Tuerlersee topographic map
  (SVG)

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WebCartography
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Dynamic web maps

• For showing dynamic phenomena
• As animated maps (movies) (eg. gondwana)
• As dynamic real-time images (ANWB)

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Dynamic web maps

• For moving through Virtual Worlds
• As a view-only animation (eg. animated GIF)
• With an interactive interface (movie) (eg.
  quicktime)
• With interactive contents (modelled) (eg. games,
  VRML)

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Web graphics today

• standardised raster formats
• fixed resolution (quality low or files large)
• original content (information) is lost
• difficult to get interactivity (other than
  clickable maps)
• binary formats (no searching/indexing of
  information, no internationalisation)
• W3C standardised GIF, JPEG
• non-standard industry (proprietary) formats
• raster or vector offering diverse, possibilities
• Countless examples, eg PDF, Flash

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Web graphics of the future

• vector graphics, resolution-independent
• "content" of information saved
• client-side rendering -gt customisable for
  viewing environment
• XML-based
• W3Cs designated backbone for the future Web

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XML (eXtensible Markup Language)

• not a fixed format, but a metalanguage a
  language for describing other languages
• lets you design your own customized markup
  languages for limitless different types of
  documents
• eg. Geographic Markup Language (GML) - OpenGIS
  standard for geographical information
• written in SGML (the international standard
  metalanguage for text markup systems ISO 8879)
• much more than a webpage language
• useable for storing and exchanging any kind of
  structured data

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Scalable Vector Graphics (SVG)

• graphic quality
• 2D vector graphics in-line raster (jpeg, gif,
  png)
• all anti-aliased
• scalability
• vectors resolution-independent (zoom, pan)
• transformable, user defined coordinate-spaces
• interactivity
• declarative (in SVG objects)
• procedural (Javascript)
• animated dynamic maps
• dynamic change of object attributes
• declarative syntax (limited file size)
• animation client-side

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Links to examples

• VRML model of Ramelerbrink
• http//kartoweb.itc.nl/public_examples/Ramelerbri
  nk_VRML.html
• Flyby Quicktime movie
• http//kartoweb.itc.nl/public_examples/flyby.mov
• Interactive application of Gondwana continental
  drift
• http//kartoweb.itc.nl/gondwana/gondwana.html
• Interactive contents (layers on/off) - Flash
• http//kartoweb.itc.nl/public_examples/overijssel
  _interactive_contents.swf
• Interactive interface (magnifiy) - Flash
• http//kartoweb.itc.nl/public_examples/overijssel
  _mapmagnifier.swf
• Interactive contents (map as menu) - Flash
• http//kartoweb.itc.nl/public_examples/overijsse
  l_interactive_interface.swf
• Interactive interface (map as menu) - HTML
• http//kartoweb.itc.nl/public_examples/Clickable_
  map_NL_provinces/index.html
• Further examples of WebMaps
• http//kartoweb.itc.nl/webcartography/workshop
  Webcartography/index.html
• Swiss map with LOD
• http//kartoweb.itc.nl/public_examples/LOD_CH_SVG
  /LOD.html
• Swiss topographic map of Tuerlersee (hillshade
  cross-sections) http//kartoweb.itc.nl/public_ex
  amples/Tuerlersee.html