Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Survey on Periocular Biometrics Research   Periocular refers to the facial region in the vicinity of the eye, including
eyelids, lashes and eyebrows. While face and irises have been extensively
studied, the periocular region has emerged as a promising trait for
unconstrained biometrics, following demands for increased robustness of face or
iris systems. With a surprisingly high discrimination ability, this region can
be easily obtained with existing setups for face and iris, and the requirement
of user cooperation can be relaxed, thus facilitating the interaction with
biometric systems. It is also available over a wide range of distances even
when the iris texture cannot be reliably obtained (low resolution) or under
partial face occlusion (close distances). Here, we review the state of the art
in periocular biometrics research. A number of aspects are described,
including: i) existing databases, ii) algorithms for periocular detection
and/or segmentation, iii) features employed for recognition, iv) identification
of the most discriminative regions of the periocular area, v) comparison with
iris and face modalities, vi) soft-biometrics (gender/ethnicity
classification), and vii) impact of gender transformation and plastic surgery
on the recognition accuracy. This work is expected to provide an insight of the
most relevant issues in periocular biometrics, giving a comprehensive coverage
of the existing literature and current state of the art.

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The categories of this paper are: quant-ph
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The categories of this paper are: econ
34
The categories of this paper are: chem-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: plasm-ph
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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: hep-ph
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The categories of this paper are: physics
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The categories of this paper are: astro-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: adap-org
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The categories of this paper are: q-fin
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The categories of this paper are: funct-an