A multi-biometric verification system lowers the verification errors by fusing information from multiple biometric sources. Information can be fused in parallel or serial modes. While parallel fusion gives a higher accuracy, it may suffer from a serious problem of taking a longer verification time. Serial fusion can alleviate this problem by allowing the users to submit a subset of the available biometric characteristics. Unfortunately, several studies show that serial fusion may not reach the level of accuracy of parallel fusion. In this paper, we propose a fusion framework which combines the advantages of both parallel and serial fusion. The core of the framework is a new concept of “confident reject region” which incurs nearly zero verification error. We evaluate our framework by performing experiments on two multi-biometric verification systems built with NIST biometric scores set release 1. The experimental results show that our framework achieves a lower equal error rate and takes a shorter verification time than standard parallel fusion.

多生物特征验证系统通过融合来自多个生物特征来源的信息来降低验证错误。信息可以以并行或串行模式融合。虽然并行融合提供了更高的准确性，但它可能会遇到需要更长验证时间的严重问题。串行融合可以通过允许用户提交可用生物特征的子集来缓解这个问题。不幸的是，一些研究表明串行融合可能无法达到并行融合的准确度水平。在本文中，我们提出了一个融合框架，它结合了并行和串行融合的优点。该框架的核心是“置信拒绝区域”的新概念，它导致几乎为零的验证错误。