Map Morphing

What is it?

Map Morphing is an interactive morph between two maps covering approximately the same region. Using both blending and distortion, the maps appear to merge into one another. This allows the user to directly visualize how the two maps diverge from one another in their presentation.

This is particularly useful when one or both maps provide views that aren’t spatially accurate (such as the typical “schematic” subway map).


We currently generate short movie sequences (between 10-20 frames), which the user controls with a slider (blending and distortion are not independently controlled). In this way they can interactively build an understanding of how the two maps are related. The movie sequences are created using the free MorphX software.


Exploratory study

An exploratory study compared the technique against other ways of relating maps. Three different pairs of maps were used (Europe-Middle East ancient/modern, London subway/street, and Toronto transit/tourist). User evaluations were positive, and participants were more likely to correctly complete ceratin navigation tasks using the morphing interface.

Morphing and recall

This larger study explored more specifically whether morphing helps to build a lasting understanding of map interrelationships. Results indicate that the technique’s effectiveness in this regard is sensitive to environmental conditions.

We are currently preparing the results of this study for publication.


D. Reilly and K.M. Inkpen. (2004). Map Morphing: Making Sense of Incongruent Maps. In Proceedings of Graphics Interface 2004. London, Canada, May 2004. pp. 231-238. (PDF)

D. Reilly. (2003). Map morphing: Visualizing relationships between map views. Poster Presentation at Graphics Interface 2003. Halifax, Canada, June 2003. (PDF)


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Maps owned by respective copyright holders

Downtown London: tourist map and the famous schematic tube map.
31mb quicktime movie

Ancient/Modern: the World According to Eratosthenes (194 B.C.) and a modern Mercator projection.
19mb quicktime movie