Showing papers by "Nalini K. Ratha published in 1996"

A real-time matching system for large fingerprint databases

Abstract: With the current rapid growth in multimedia technology, there is an imminent need for efficient techniques to search and query large image databases. Because of their unique and peculiar needs, image databases cannot be treated in a similar fashion to other types of digital libraries. The contextual dependencies present in images, and the complex nature of two-dimensional image data make the representation issues more difficult for image databases. An invariant representation of an image is still an open research issue. For these reasons, it is difficult to find a universal content-based retrieval technique. Current approaches based on shape, texture, and color for indexing image databases have met with limited success. Further, these techniques have not been adequately tested in the presence of noise and distortions. A given application domain offers stronger constraints for improving the retrieval performance. Fingerprint databases are characterized by their large size as well as noisy and distorted query images. Distortions are very common in fingerprint images due to elasticity of the skin. In this paper, a method of indexing large fingerprint image databases is presented. The approach integrates a number of domain-specific high-level features such as pattern class and ridge density at higher levels of the search. At the lowest level, it incorporates elastic structural feature-based matching for indexing the database. With a multilevel indexing approach, we have been able to reduce the search space. The search engine has also been implemented on Splash 2-a field programmable gate array (FPGA)-based array processor to obtain near-ASIC level speed of matching. Our approach has been tested on a locally collected test data and on NIST-9, a large fingerprint database available in the public domain.

Smartcard Based Authentication

Abstract: In the modern electronic world, authentication of a person is an important task in many areas of day-to-day life. Using a biometrics to authenticate a person’s identity has several advantages over the present practices of passwords and/or authentication cards using magnetic stripes or bar codes. However, with the use of a biometrics there is an open issue of misuse of the biometrics for purposes that the owner of the biometrics may not be aware of. In this chapter, we propose a new method of remote authentication that combines the security of a smartcard with the accuracy and convenience of biometrics to authenticate the identity of a person. With this approach, the need to access a large biometrics database is eliminated. The proposed method can be used in many application areas including system security, electronic commerce and access control.

FPGA-based high performance page layout segmentation

Abstract: A page layout segmentation algorithm for locating text, background and halftone areas is presented. The algorithm has been implemented on Splash 2-an FPGA-based array processor. The speed as determined by the Xilinx synthesis tools projects an application speed of 5 MHz. For documents of size 1,024/spl times/1,024 pixels, a significant speedup of two orders of magnitude compared to a SparcStation 20 has been achieved.