M.I.T. Media Laboratory Vision and Modeling Group Technical Report No. 198
On the use of ``Nulling'' Filters to Separate Transparent Motions
Trevor Darrell and Eero Simoncelli
Transparent motions can be isolated in the Fourier domain, using derivative
prefilters that selectively null the spatio-temporal energy consistent with
the gradient constraint imposed by each component velocity. We use these
``nulling'' prefilters to robustly compute the support a particular velocity
has at a point despite other velocities that may also be present at that
point. Images are decomposed into a set of global constraints that account
for a maximal amount of the motion information in the sequence. Adopting
global motion hypotheses and a selection mechanism based on finding a parsimonious
subset of these hypotheses, we show results separating motion stimuli into
their constituent layers, even when those layers are transparently combined
in the stimuli.
A Postscript
version of this report is available.