Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A single scale retinex based method for palm vein extraction   Palm vein recognition is a novel biometric identification technology. But how
to gain a better vein extraction result from the raw palm image is still a
challenging problem, especially when the raw data collection has the problem of
asymmetric illumination. This paper proposes a method based on single scale
Retinex algorithm to extract palm vein image when strong shadow presents due to
asymmetric illumination and uneven geometry of the palm. We test our method on
a multispectral palm image. The experimental result shows that the proposed
method is robust to the influence of illumination angle and shadow. Compared to
the traditional extraction methods, the proposed method can obtain palm vein
lines with better visualization performance (the contrast ratio increases by
18.4%, entropy increases by 1.07%, and definition increases by 18.8%).

28
The categories of this paper are: alg-geom
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
37
The categories of this paper are: supr-con
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
18
The categories of this paper are: econ
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas