Sebastiano Impedovo

Automatic bankcheck processing : A new engineered system

A new bankcheck processing system is presented in this paper. A full exploitation of the contextual knowledge, together with a multi-expert approach, have been used both to analyze the complex shape of handwritten text and to design the system. Several processing modules have been integrated in the system. Some of the most relevant are those for data acquisition, preprocessing, machine-printed numeral recognition, layout analysis, courtesy amount recognition, legal amount recognition, amount validation, and signature verification. Some combination techniques have also been used in the system. Reuse and maintenance of the system were two of the main goals of the designing process and the Khoros software tool was used for this purpose.

Recent advancements in automatic signature verification

This paper presents some of the main strategies for dynamic and static verification of handwritten signatures and focuses the most promising directions of scientific research, starting from the analysis of the literature of the last decade.

A multi-expert signature verification system for bankcheck processing

In this paper a multi-expert signature verification system is presented. The system has been specifically designed for applications in the field of bankcheck processing. For this purpose, it combines three different algorithms for signature verification. A wholistic approach is used in the first algorithm, a component-oriented approach is used in the second and third algorithms. The second algorithm is based on a structure-based procedure, the third algorithm uses a highly-adaptive neural network. The three algorithms are combined in the multi-expert system by a voting strategy.

A new technique for fast number comparison in the residue number system

A technique for number comparison in the residue number system is presented, and its theoretical validity is proved. The proposed solution is based on using a diagonal function to obtain a magnitude order of the numbers. In a first approach the function is computed using a suitable extra modulus. In the final implementation of the technique the extra modulus has been inserted in the set of moduli of the residue system, avoiding redundancy. The technique is compared with other approaches. >

Verification of Handwritten Signatures: an Overview

In the information and communication personal verification is a crucial aspect. Among the different means for personal verification, handwritten signature plays a fundamental role since signature is the most diffuse means for personal verification in our daily life. In this paper a brief overview of the field of handwritten signature verification is presented and some of the most relevant perspectives are highlighted.

Analysis of stability in hand-written dynamic signatures

This paper presents a new technique to evaluate the local stability in hand-written dynamic signatures and use the results to improve the process of automated signature verification. The experimental results points out the usefulness of integrating stability, information into the signature verification process.

Optimal zoning design by genetic algorithms

In pattern recognition, zoning is one of the most effective methods for extracting distinctive characteristics from patterns. So far, many zoning methods have been proposed, based on standard partitioning criteria of the pattern image. In this paper, a new technique is presented for zoning design. Zoning is considered as the result of an optimization problem and a genetic algorithm is used to find the optimal zoning that minimizes the value of the cost function associated to the classification. For this purpose, a new description of zonings by Voronoi diagrams is used, which is found to be well suited for the genetic technique. The experimental tests, carried out in the field of handwritten numeral and character recognition, show that the proposed technique leads to zonings superior to traditional zoning methods

Selection of reference signatures for automatic signature verification

This paper presents an effective procedure to select the reference specimens for a signature verification system. Specifically, from the analysis of local stability in handwritten signatures, a suitable measure is proposed to determine the capability of different sets of signatures in supporting effective verification. The measure uses a correlation-based criterium which detects and recovers non-linear time distortions in different specimens. In the experimental test, the selected set of signatures has been used for reference in a system for dynamic signature verification based on a multi-expert verification strategy. The experimental results points out the capability of the new technique in selecting effective reference signatures.

Component-oriented algorithms for signature verification

Signing is a complex and highly variable process. It results from simple bodily motions of a ballistic nature whose combined effects produce the fundamental components of the signature. Therefore, ...

A Multi-expert System for Dynamic Signature Verification

This paper presents a multi-expert system for dynamic signature verification. The system combines three experts whose complementar behaviour is achieved by using both different features and verification strategies. The first expert uses shape-based features and performs signature verification by a wholistic analysis. The second and third expert uses speedbased features and performs signature verification by a regional analysis. Finally, the verification responses provided by the three experts are combined by majority voting.