28,122 research outputs found
Depth Estimation Through a Generative Model of Light Field Synthesis
Light field photography captures rich structural information that may
facilitate a number of traditional image processing and computer vision tasks.
A crucial ingredient in such endeavors is accurate depth recovery. We present a
novel framework that allows the recovery of a high quality continuous depth map
from light field data. To this end we propose a generative model of a light
field that is fully parametrized by its corresponding depth map. The model
allows for the integration of powerful regularization techniques such as a
non-local means prior, facilitating accurate depth map estimation.Comment: German Conference on Pattern Recognition (GCPR) 201
Numerical calculation of three-point branched covers of the projective line
We exhibit a numerical method to compute three-point branched covers of the
complex projective line. We develop algorithms for working explicitly with
Fuchsian triangle groups and their finite index subgroups, and we use these
algorithms to compute power series expansions of modular forms on these groups.Comment: 58 pages, 24 figures; referee's comments incorporate
The Refined Topological Vertex
We define a refined topological vertex which depends in addition on a
parameter, which physically corresponds to extending the self-dual graviphoton
field strength to a more general configuration. Using this refined topological
vertex we compute, using geometric engineering, a two-parameter (equivariant)
instanton expansion of gauge theories which reproduce the results of Nekrasov.
The refined vertex is also expected to be related to Khovanov knot invariants.Comment: 70 Pages, 23 Figure
Refined descendant invariants of toric surfaces
We construct refined tropical enumerative genus zero invariants of toric
surfaces that specialize to the tropical descendant genus zero invariants
introduced by Markwig and Rau when the quantum parameter tends to . In the
case of trivalent tropical curves our invariants turn to be the
Goettsche-Schroeter refined broccoli invariants. We show that this is the only
possible refinement of the Markwig-Rau descendant invariants that generalizes
the Goettsche-Schroeter refined broccoli invariants. We discuss also the
computational aspect (a lattice path algorithm) and exhibit some examples.Comment: 30 pages, 7 figures; matches the published versio
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