Querying GIS with Animated Spatial Sketches Volker Haarslev and - - PowerPoint PPT Presentation

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Querying GIS with Animated Spatial Sketches Volker Haarslev and - - PowerPoint PPT Presentation

Dec 21, 2022 257 likes •424 views

Querying GIS with Animated Spatial Sketches Volker Haarslev and Michael Wessel University of Hamburg, Germany haarslev@informatik.uni-hamburg.de http://kogs-www.informatik.uni-hamburg.de/~haarslev/ Motivation VISCO's Language Elements

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  • Motivation
  • VISCO's Language Elements
  • Sketching Queries for City Map Examples
  • Conclusion
  • (Demo Slides)

Querying GIS with Animated Spatial Sketches

Volker Haarslev and Michael Wessel University of Hamburg, Germany

haarslev@informatik.uni-hamburg.de http://kogs-www.informatik.uni-hamburg.de/~haarslev/

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Motivation

  • Sketch constellation of spatial objects
  • Topological and geometric

relationships between components are important

  • Consider relationships in sketches as

query constraints

  • Interpret sketch as “sentence” of a

visual query language

  • Sketch constellation of spatial objects
  • Topological and geometric

relationships between components are important

  • Consider relationships in sketches as

query constraints

  • Interpret sketch as “sentence” of a

visual query language

Query Spatial Databases (GIS)

  • Relaxation of geometrical

(topological) constraints needed

  • Derived constraints (e.g. centered)
  • Relaxation of geometrical

(topological) constraints needed

  • Derived constraints (e.g. centered)

Explicit Meta Information

Building

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Naive Physics Metaphor

Physical properties visualize semantics

  • 0-D: marbles, nails, swivel joints

e.g. marble: roll around, change position

  • 1-D: (cross) beams, rubber bands, telescop

antenna e.g. rubber band: stretch, shrink, wrap around

  • 2-D: enclosures, transparencies

e.g. enclosure: fenced area trapping marbles Physical properties visualize semantics

  • 0-D: marbles, nails, swivel joints

e.g. marble: roll around, change position

  • 1-D: (cross) beams, rubber bands, telescop

antenna e.g. rubber band: stretch, shrink, wrap around

  • 2-D: enclosures, transparencies

e.g. enclosure: fenced area trapping marbles

Semantics of Query Objects

  • Degrees of freedom gained by relaxations
  • Variations of user sketches visualized by

animations

  • Degrees of freedom gained by relaxations
  • Variations of user sketches visualized by

animations

Animation

Vivid Spatial Constellations

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VISCO’s Language Elements

Fixpoint Marble Nail Beam (Atomic) Rubber Band Crossbeams Fixed Angle Minimal Angle Maximal Angle Min + Max Angle

Parallelogram as example

Compass Enclosure Polygon Transparency Film

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  • Transparency film (of an overhead projector)
  • Rectangular shape
  • Own local cartesian coordinate system
  • Can be scaled, translated, rotated, and stacked up
  • Fixpoint (w.r.t. transformations) is required
  • Any nail (isolated or as vertex) on transparency
  • Users interactively draw VISCO's query

elements

  • Collection of drawn elements defines

(sub)constellation

  • Geometrical and topological relationships are

relevant

  • Transparency film (of an overhead projector)
  • Rectangular shape
  • Own local cartesian coordinate system
  • Can be scaled, translated, rotated, and stacked up
  • Fixpoint (w.r.t. transformations) is required
  • Any nail (isolated or as vertex) on transparency
  • Users interactively draw VISCO's query

elements

  • Collection of drawn elements defines

(sub)constellation

  • Geometrical and topological relationships are

relevant

VISCO: Transparency Films

Basic Building Block

  • One transparency

as drawing sheet

  • Two transparencies

each with objects

  • One transparency

as drawing sheet

  • Two transparencies

each with objects

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Example: Various Quadrilaterals

  • matches at most 4

line segments

  • marbles act as

swivel joints and may float inside of enclosure

  • rubber bands may

stretch or shrink

  • matches at most 4

line segments

  • marbles act as

swivel joints and may float inside of enclosure

  • rubber bands may

stretch or shrink

4

  • 4 beams as edges
  • marbles act as

swivel joints and may float inside of enclosure

  • beams have a

fixed length

  • 4 beams as edges
  • marbles act as

swivel joints and may float inside of enclosure

  • beams have a

fixed length

  • 4 beams as edges
  • marbles may float

inside of enclosure

  • beams have a

fixed length and a fixed right angle

  • fixed orientation
  • 4 beams as edges
  • marbles may float

inside of enclosure

  • beams have a

fixed length and a fixed right angle

  • fixed orientation
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VISCO: Enclosures and Points

  • Enclosure is meta object
  • visualized by a gray texture
  • all enclosed objects are "trapped" and

must stay inside of their enclosure

  • Two types of enclosures
  • translucent: also consider

relationships with other visible objects

  • opaque: hidden objects are excluded
  • Computed ε-enclosures
  • interior or exterior (border) of an
  • bject
  • radius is required
  • Enclosure is meta object
  • visualized by a gray texture
  • all enclosed objects are "trapped" and

must stay inside of their enclosure

  • Two types of enclosures
  • translucent: also consider

relationships with other visible objects

  • opaque: hidden objects are excluded
  • Computed ε-enclosures
  • interior or exterior (border) of an
  • bject
  • radius is required

Enclosure

  • Semantics of nails not affected
  • Marbles are only allowed inside
  • f enclosures
  • Marbles may freely change their

position

  • Semantics of nails not affected
  • Marbles are only allowed inside
  • f enclosures
  • Marbles may freely change their

position

Point

4

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Example: Rectangle Touching Scalable Circle

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City Map Example: Öjendorf as Subsection of Hamburg

  • Areas intended as

query matches are marked

  • Input for query

processing is a vector representation of this map

  • Areas intended as

query matches are marked

  • Input for query

processing is a vector representation of this map

Map data donated by the 'Amt für Geoinformation und Vermessung'

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City Map Example: Church in vicinity of subway station

  • Create transparency of fixed size

(300 x 300 m)

  • Draw a fixpoint (nail) and attach

the concept 'SubwayStation' to fixpoint

  • fixpoint may coincide with any

point object in database

  • Generate circular ε-enclosure
  • fixpoint as center
  • radius of 100 m
  • Draw a marble inside of the

enclosure and attach the concept 'Church' to marble

  • Create transparency of fixed size

(300 x 300 m)

  • Draw a fixpoint (nail) and attach

the concept 'SubwayStation' to fixpoint

  • fixpoint may coincide with any

point object in database

  • Generate circular ε-enclosure
  • fixpoint as center
  • radius of 100 m
  • Draw a marble inside of the

enclosure and attach the concept 'Church' to marble

Snapshots of query construction with example of intended match

300m 300m 300m 300m SubwayStation Church 300m 300m SubwayStation

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City Map Example: 3 adjacent buildings aligned in parallel (1)

Create scalable, rotatable transparency with enclosure Create scalable, rotatable transparency with enclosure

4 4 4 Building Building Building

Sketch three quadrilaterals Sketch three quadrilaterals

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City Map Example: 3 adjacent buildings aligned in parallel (2)

Constrain orientation of edges as visualized Constrain orientation of edges as visualized

4 4 4 Building Building Building 4 4 4 Building Building Building

Generate center points of quadrilaterals (marbles) Generate center points of quadrilaterals (marbles)

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City Map Example: 3 adjacent buildings aligned in parallel (3)

Draw enclosure confining center points more closely Draw enclosure confining center points more closely

Example of intended match

4 4 4 Building Building Building

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Conclusion and Ongoing Research

  • VISCO is innovative compared to other relevant approaches

(see related work in paper)

  • geometric as well as topological queries or combination of both
  • high expressiveness by interpreting topological relations as

qualitative constraints enriched with meta information

  • simple but powerful 'naive physics' metaphor
  • approximate or vague objects/constellations possible
  • Prototype implementation partially completed (user interface)
  • Query semantics specified by translational semantics (typed

lambda calculus)

  • Description logic framework for query processing and
  • ptimization is under development
  • VISCO is innovative compared to other relevant approaches

(see related work in paper)

  • geometric as well as topological queries or combination of both
  • high expressiveness by interpreting topological relations as

qualitative constraints enriched with meta information

  • simple but powerful 'naive physics' metaphor
  • approximate or vague objects/constellations possible
  • Prototype implementation partially completed (user interface)
  • Query semantics specified by translational semantics (typed

lambda calculus)

  • Description logic framework for query processing and
  • ptimization is under development