Marking up a world: visual markup for creating and manipulating virtual models.

We describe Pantheia, a system that constructs virtual models of real spaces from collections of images, through the use of visual markers that guide and constrain model construction. To create a model users simply 'mark up' the real world scene by placing preprinted markers that describe scene elements or impose semantic constraints. Users then collect still images or video of the scene. From this input, Pantheia automatically and quickly produces a model. The Pantheia system was used to produce models of two rooms that demonstrate the effectiveness of the approach.