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Wavelet Analysis of Resultant Velocity Belonging to Genuine and Forged Signatures
Author(s) -
Syed Ahmad Sharifah Mumtazah,
Loo Ling Yim,
Wan Adnan Wan Azizun,
Md. Anwar Rina
Publication year - 2017
Publication title -
journal of forensic sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.715
H-Index - 96
eISSN - 1556-4029
pISSN - 0022-1198
DOI - 10.1111/1556-4029.13303
Subject(s) - wavelet , pattern recognition (psychology) , signature (topology) , sample (material) , artificial intelligence , statistical hypothesis testing , mathematics , statistics , discrete wavelet transform , wavelet transform , computer science , geometry , physics , thermodynamics
This study presents a wavelet analysis of resultant velocity features belonging to genuine and forged groups of signature sample. Signatures of individuals were initially classified based on visual human perceptions of their relative sizes, complexities, and legibilities of the genuine counterparts. Then, the resultant velocity was extracted and modeled through wavelet analysis from each sample. The wavelet signal was decomposed into several layers based on maximum overlap discrete wavelet transform ( MODWT ). Next, the zero crossing rate features were calculated from all the high wavelet sub‐bands. A total of seven hypotheses were then tested using a two‐way ANOVA testing methodology. Of these, four hypotheses were conducted to test for significance differences between distributions. In addition, three hypotheses were run to provide test for interaction between two factors of signature authentication versus perceived classification. The results demonstrated that both feature distributions belonging to genuine and forged groups of samples cannot be distinguished by themselves. Instead, they were significantly different under the influence of two other inherent factors, namely perceived size and legibility. Such new findings are useful information particularly in providing bases for forensic justifications in establishing the authenticity of handwritten signature specimens.