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Steerable Filters
Illustrated are a set of even-symmetric (top row) and odd-symmetric
(bottom row) steerable wedge filters. These filters are
polar-separable, where the angular portion of the even/odd-symmetric
filters are constructed from a linear combination of the first N
cos/sin harmonics. A filter at any orientation may be constructed
from a linear combination of these basis filters.
These filters differ from the traditional steerable filters which are
based on directional derivatives whose symmetry produces orientation
responses that are periodic with period pi, independent of the
underlying image structure. The steerable wedge filters are spatially
asymmetric and therefore are more likely to accurately represent the
underlying image structure.
Matlab routines for constructing and applying
steerable wedge filters.
(Collaborative work with Eero Simoncelli)
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