Figure from ROBOT, Moravec, Oxford, 1998, Chapter 2: Caution! Robot Vehicle!, page 39
Sparse map from Cart in 1979, Dense grid from Crayfish in 1997

1979 and 1997-3D maps from stereoscopic images

In each example about forty images similar to the ones in the upper half of the diagrams were stereoscopically processed to make the maps below them. The map on the left shows the Cart's position near the beginning of a run, its camera field of view, its planned path, and a kind of perspective view of features that passed all consistency checks. Each feature is a black dot linked to the ground by a diagonal line. The diagonal's length is the feature's height; where it meets the ground is its forward and lateral position. The features are also marked by dots overlaid on the camera image. To aid interpretation, about a dozen clusters of features were hand-labeled with the identity of the object on which they were found. The map on the right is a perspective view of the occupied cells in a 256 by 256 by 64 grid representing a 6 meter square by 2 meter high bite of the office above. To aid visualization, the cells in about a dozen box-shaped volumes selected by hand were ``spotlighted'' with distinctive tints.