  The competitive Coding approach (CompCode) is one of the most promising
methods for palmprint recognition. Due to its high performance and simple
formulation, it has been continuously studied for many years. However, although
numerous variations of CompCode have been proposed, a detailed analysis of the
method is still absent. In this paper, we provide a detailed analysis of
CompCode from the perspective of linear discriminant analysis (LDA) for the
first time. A non-trivial sufficient condition under which the CompCode is
optimal in the sense of Fisher's criterion is presented. Based on our analysis,
we examined the statistics of palmprints and concluded that CompCode deviates
from the optimal condition. To mitigate the deviation, we propose a new method
called Class-Specific CompCode that improves CompCode by excluding
non-palm-line areas from matching. A nonlinear mapping of the competitive code
is also applied in this method to further enhance accuracy. Experiments on two
public databases demonstrate the effectiveness of the proposed method.
