Map Morphing

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 certain navigation tasks using the morphing interface [2].

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 for recall of relationships is affected by the setting in which it is used. Participants who used the technique in a casual, noisy atrium environment had better recall than those who used it in a controlled, quiet white room [1], while the same effect was not found for juxtaposing maps.


  1. Reilly, D. F. and Inkpen, K. M. (2007) White rooms and morphing don't mix: setting and the evaluation of visualization techniques. In Proceedings of the SIGCHI Conference on Human Factors in Computing Systems (CHI '07), San Jose, CA, USA, April 2007, 111-120. doi:10.1145/1240624.1240640
  2. Reilly, D. and Inkpen, K. M. (2004). Map Morphing: Making Sense of Incongruent Maps. In Proceedings of Graphics Interface 2004. London, Canada, May 2004. pp. 231-238. (PDF)
  3. Reilly, D. (2003). Map morphing: Visualizing relationships between map views. Poster Presentation at Graphics Interface 2003. Halifax, Canada, June 2003. (PDF)