  Lines are the most essential and discriminative features of palmprint images,
which motivate researches to propose various line direction based methods for
palmprint recognition. Conventional methods usually capture the only one of the
most dominant direction of palmprint images. However, a number of points in
palmprint images have double or even more than two dominant directions because
of a plenty of crossing lines of palmprint images. In this paper, we propose a
local multiple directional pattern (LMDP) to effectively characterize the
multiple direction features of palmprint images. LMDP can not only exactly
denote the number and positions of dominant directions but also effectively
reflect the confidence of each dominant direction. Then, a simple and effective
coding scheme is designed to represent the LMDP and a block-wise LMDP
descriptor is used as the feature space of palmprint images in palmprint
recognition. Extensive experimental results demonstrate the superiority of the
LMDP over the conventional powerful descriptors and the state-of-the-art
direction based methods in palmprint recognition.
