Shape From Moments*
Gene H. Golub
Abstract:
We discuss the problem of recovering a planar polygon
from its measured complex moments. These moments correspond to an
indicator function defined over the polygon's support. Previous
work on this problem gave necessary and sufficient conditions for
such successful recovery process and focused mainly on the case of
exact measurements being given. We extend these
results and treat the same problem in the case where a longer than
necessary series of noise corrupted moments is given. Similar to
methods found in array processing, system identification, and
signal processing, we discuss a set of possible estimation
procedures which are based on the Prony and the Pencil methods,
relate them one to the other, and compare them through
simulations. We then present an improvement over these methods
based on the direct use of the Maximum-Likelihood estimator,
exploiting the above methods as initialization. We show that VarPro
algorithm can be used for boost accuracy of the estimated vertices.
Finally, we show how regularization, and thus Maximum A-posteriori
Probability estimator could be applied to reflect prior knowledge
about the recovered polygon. Numerical examples that illustrate the
proposed algorithms and their performance are shown.
* Joint work with Peyman Milanfar and Michael Elad