Revisiting Competitive Coding Approach for Palmprint Recognition: A Linear Discriminant Analysis Perspective
This work addresses a specific problem in biometric recognition for palmprint identification, but it is incremental as it builds upon existing competitive coding methods.
The paper tackled the lack of detailed analysis of the competitive coding approach for palmprint recognition by providing a linear discriminant analysis perspective, presenting a sufficient condition for optimality and proposing a new method that improved accuracy on two public databases.
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.