2D: Focus Context

1
2-D FocusContext

• cs5984 Information Visualization
• Chris North

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Strategies

• Detail only detail without overview
• Zooming detail becomes overview
• Transparency detail on top of overview
• OverviewDetail detail next to overview
• FocusContext detail within overview
• FocusContext
• Distortion-oriented display
• Fisheye

3
Wendy Schafer

• Moosburg
• moosburg.cs.vt.edu

4
Document Lens

• Robertson, Document Lens, p 562
• priya, parool

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Bifocal Display

• Leung, Bifocal displays
• alex, qiang

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Distortion Functions

• Mapping from info surface to display surface

f
Information surface
Display surface
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Visual Transfer Functions
Display surface
Display surface
Information surface
Information surface
Identity function normal flat overview
Bifocal
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Magnification Functions
Bifocal
1st Derivative
Magnification
Magnification
Information surface
Information surface
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Bifocal Display
Disadvantage 1 dimensional stretching on the 4
sides
Bifocal
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Perspective Wall / Document Lens
Context gradually disappears
Perspective
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NonLinear Magnification

• http//www.cs.indiana.edu/hyplan/tkeahey/research/
  nlm/nlm.html
• http//www.cs.indiana.edu/hyplan/tkeahey/research/
  papers/infovis.98.html

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Bubble
Disadvantage local context highly de-magnified
Bubble
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Fisheye, wide-angle lens
Disadvantage no flat area
Wide-angle
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FocusContext

• Bifocal
• Perspective
• Bubble
• Wide-angle

15
Quiz TableLens

• Bifocal!

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Fisheye Menus

• combination of perspective

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Calendar

• Leung

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Why not magnifying glass?

• Hides local context

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FC vs. OD

• - eye swapping
• higher zoom factor, higher scale
• really high scale with intermediates
• implementation (no math)

• - distortion
• smooth transition
• more screen space efficient
• easier layout
• - no flat overview, turn offf focus

20
Next Week

• Tues Visual Overview Strategies
• Stasko, Information Mural
• ben, ahmed
• Rayson, Aggregate Towers
• anil, supriya
• Thurs Multiple View Strategies
• Chi, Visualization Spreadsheet
• mudita, abhi
• North, Snap-Together Visualization
• varun, kumar

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Assignment

• Homework 2 due today