Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Sparse Representation of Astronomical Images   Sparse representation of astronomical images is discussed. It is shown that a
significant gain in sparsity is achieved when particular mixed dictionaries are
used for approximating these types of images with greedy selection strategies.
Experiments are conducted to confirm: i)Effectiveness at producing sparse
representations. ii)Competitiveness, with respect to the time required to
process large images.The latter is a consequence of the suitability of the
proposed dictionaries for approximating images in partitions of small
blocks.This feature makes it possible to apply the effective greedy selection
technique Orthogonal Matching Pursuit, up to some block size. For blocks
exceeding that size a refinement of the original Matching Pursuit approach is
considered. The resulting method is termed Self Projected Matching Pursuit,
because is shown to be effective for implementing, via Matching Pursuit itself,
the optional back-projection intermediate steps in that approach.

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The categories of this paper are: cond-mat
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The categories of this paper are: physics
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The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
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The categories of this paper are: eess
30
The categories of this paper are: q-alg
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The categories of this paper are: q-fin
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The categories of this paper are: adap-org
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The categories of this paper are: hep-ph
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The categories of this paper are: stat
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The categories of this paper are: funct-an
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The categories of this paper are: chem-ph
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The categories of this paper are: solv-int
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The categories of this paper are: quant-ph
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The categories of this paper are: nucl-th
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The categories of this paper are: chao-dyn