Annotating Real World objects using a Steerable Projector-Camera Unit

We describe the annotation of real world objects with labels similar to the "tool tips" known from desktop interfaces using a steerable projector-camera unit. Labels containing text or graphics are projected onto objects or next to objects on suitable surfaces and are placed automatically according to a set of weighted criteria ensuring an unambiguous mapping between labels and labeled objects as well as consistency among the set of labels. The method has been implemented in our instrumented environment to form the basis for making this environment to some extent selfexplaining.