Labeling Rylan Cottrell Excentric Labeling Textual information is

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 � D 1 – Except for sliding in or out of the view area, labels should not vanish when zooming in or appear when zooming out. � D 2 – As long as a label is visible, its position and size should change continuously under pan and zoom. � D 3 – Except for sliding in or out of the view area, labels should not vanish or appear during panning. � D 4 – 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