Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Learn priors on the spatiotemporal relationship between edges in the alpha matte and the composite image
 

Summary:  Learn priors on the spatiotemporal relationship between edges in the
alpha matte and the composite image
Fit these priors to natural image statistics models to avoid over-fitting
These priors propagate alpha values along, but not across, edge surfaces in
both space and time

We calculate the maximum a posteriori (MAP) estimate of the foreground
image F and the alpha-matte given C and B:

The MAP estimation is converted into an energy minimization by taking the
negative log-likelihood of the posterior, and noting that p(C) and p(B) do not
depend on the unknowns F and .
This is calculated over 100,000's of variables using the well-honed Matlab
optimizer fmincon. Derivatives of the energy function are computed using
Maple, and automatically written to C source code. An analytical sparse
Hessian is assembled from these derivatives allowing the use of efficient
sparse solvers.
Nicholas Apostoloff and Andrew W. Fitzgibbon
University of Oxford
{nema,awf}@robots.ox.ac.uk

  

Source: Apostoloff, Nicholas - Department of Engineering Science, University of Oxford

 

Collections: Engineering; Computer Technologies and Information Sciences