A new energy-based method for motion estimation of opaque or transparent ob
jects is described, which uses a reduced number of spatio-temporal Gabor fi
lters. This method is based on the simplifying hypothesis of additive trans
parency and it copes very well with two specific cases: transparent objects
in motion over a fixed background, or over a background moving at the same
speed but going in opposite directions. (C) 2001 Elsevier Science B.V. All
rights reserved.