1. A system for classifying dominant singularity in a digital fingerprint image, the system comprising: an image enhancement unit configured to enhance the digital fingerprint image to generate an enhanced digital fingerprint image; a feature extraction and analysis unit configured to analyze image features within each of a predetermined number of local segments of the enhanced digital fingerprint image to translate the image features into orientations that estimate dominant structures in the underlying enhanced digital fingerprint image; a major block segmentation unit configured to determine, for each of a predetermined number of major blocks in the enhanced digital fingerprint image, a dominant orientation of ridge and valley patterns in the enhanced digital fingerprint image, wherein each major block comprises multiple local segments; a feature orientation calculation and extraction unit configured to generate an Orientation Feature Vector by listing, according to a pre-determined sequence, the dominant orientations of each of the major blocks of the enhanced digital fingerprint image; at least one memory storing a bank of regular expressions corresponding to a class of fingerprint images, wherein each regular expression describes sequences of dominant orientations associated with previous Orientation Feature Vectors generated from digital fingerprint images belonging to the class of fingerprint images; and a regular expression matching unit configured to determine whether the digital fingerprint image belongs to the class of fingerprint images by determining whether any of the regular expressions in the bank of regular expressions match the Orientation Feature Vector generated by the feature orientation calculation and extraction unit.