Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Unassisted Quantitative Evaluation Of Despeckling Filters   SAR (Synthetic Aperture Radar) imaging plays a central role in Remote Sensing
due to, among other important features, its ability to provide high-resolution,
day-and-night and almost weather-independent images. SAR images are affected
from a granular contamination, speckle, that can be described by a
multiplicative model. Many despeckling techniques have been proposed in the
literature, as well as measures of the quality of the results they provide.
Assuming the multiplicative model, the observed image $Z$ is the product of two
independent fields: the backscatter $X$ and the speckle $Y$. The result of any
speckle filter is $\widehat X$, an estimator of the backscatter $X$, based
solely on the observed data $Z$. An ideal estimator would be the one for which
the ratio of the observed image to the filtered one $I=Z/\widehat X$ is only
speckle: a collection of independent identically distributed samples from Gamma
variates. We, then, assess the quality of a filter by the closeness of $I$ to
the hypothesis that it is adherent to the statistical properties of pure
speckle. We analyze filters through the ratio image they produce with regards
to first- and second-order statistics: the former check marginal properties,
while the latter verifies lack of structure. A new quantitative image-quality
index is then defined, and applied to state-of-the-art despeckling filters.
This new measure provides consistent results with commonly used quality
measures (equivalent number of looks, PSNR, MSSIM, $\beta$ edge correlation,
and preservation of the mean), and ranks the filters results also in agreement
with their visual analysis. We conclude our study showing that the proposed
measure can be successfully used to optimize the (often many) parameters that
define a speckle filter.

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The categories of this paper are: chao-dyn
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
15
The categories of this paper are: nucl-ex
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The categories of this paper are: q-alg
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The categories of this paper are: funct-an
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
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The categories of this paper are: quant-ph
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The categories of this paper are: astro-ph
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: adap-org