关键词: 指纹自动识别系统, 汗孔特征, 稳定性, 变异系数, 偏离度

Abstract: Objective To study the stability of pore features with AFIS fingerprint database. Methods By using of AFIS function of duplicate checking, the fingerprint images collected from the same person at different times are searched, and the distances and angles between pore feature and detail features in the collected fingerprint images are observed and measured. Besides，the statistics above are analyzed with the coefficient of variation and degree of deviation. Results The shape and size of the pore features vary greatly, the stability are poor, and the position of the pore features change less. The coefficient of variation of distance and angle between pore features and detail features is less than 8%, and most of the deviation is less than 9%. The position variation is in the acceptable range. Conclusion The physiological changes of pore features are far less obvious than the changes causing by different methods and pressure when collecting the fingerprint. The distribution of the pore features, which are measured referred to nearby the detail feature, remain stable at a certain physiological stage. The physiological stability of pore features provides a theoretical basis for fingerprint identification assisted by pore features.

Key words: automatic fingerprint identification system, pore feature, stability, coefficient of variation, degree of deviation