Labeling

Rylan Cottrell

Excentric Labeling Textual information is often required to

support /supplement a visualization for the identification of critical elements of the display.

How they see the problem: Lack of labels. Restrictions on how labels are viewed, i.e., labels

can only be viewed one at a time (e.g., tooltips). Labels can obscure data. Poor placement of labels can lead to ambiguity. Data density. Long labels.

Taxonomy of Labeling Techniques Goal of the layout.

Readable. No ambiguity between the element and its label. Labels do not obscure pertinent information.

Static Label-at-all-cost Rapid Label – overlaps, data occlusion. Label-what-you-can – only labels that fit are

displayed.

Taxonomy Cont’d Dynamic

Cursor sensitive balloon label – think tooltip. All or Nothing – labels appear when the number of

objects fall below a certain limit.

Scatter plot - Excentric

Map - Zoom

Map - Excentric

Cartography - Excentric

Particle-Based Labeling Non-overlapping labeling is NP-Hard. Needs

Real-time interaction No preprocessing No label conflicts - No occlusion Does not obscure data No constraints on the labels Global labeling solution

Labeling Pipeline

Conflict Detection

Results

Dynamic Map Labeling Static Map – goal is to maximize information.

Dynamic Map. Continuous zoom. Continuous pan. Interactive speed. Purpose – navigation.

Dynamic Label Consistency D1 – Except for sliding in or out of the view

area, labels should not vanish when zooming in or appear when zooming out.

D2 – As long as a label is visible, its position and size should change continuously under pan and zoom.

D3 – Except for sliding in or out of the view area, labels should not vanish or appear during panning.

D4 – The placement and selection of any label is a function of the current map state.

Dynamic selection – at which scales a label will be selected.

Dynamic placement – a static placement for each scale at which a label is selected.

Filtering Number of labels much larger then what can be

shown in any given view area.

Preprocessing Determine dynamic placement. Choose the active range for each label.

Interaction Filter labels on the basis.

Geographic region. Scale.

For each label not filtered out, display iff the current scale is in active range.

NYC

NYC - Zoom

Google Earth