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. 2022 Mar;67(2):651-668.
doi: 10.1111/1556-4029.14927. Epub 2021 Nov 3.

Digitally captured signatures: A method for the normalization of force through calibration and the use of the zeta function

Nikolaos Kalantzis  1   2 , Andrew W G Platt  2
Affiliations

Digitally captured signatures: A method for the normalization of force through calibration and the use of the zeta function

Nikolaos Kalantzis et al. J Forensic Sci. 2022 Mar.

Abstract

Digitally captured signatures (DCS) are entering the scope of the Forensic Handwriting Examiner (FHE), and the meaningful comprehension and comparison of the captured information is essential in order to proceed to the examination of authenticity of DCS. In DCS solutions, force is captured and presented as pressure levels, but the relation between exercised force and the assigned pressure levels is not provided by the manufacturers of these solutions. For this purpose, we constructed an experimental array that allows the correlation of exercised force and assigned pressure levels, in a combination of three different digitizers, six different styli and four different capturing software. This process let us calculate the correlation function that assigns pressure levels to force for each solution (called the Zeta Function). Through this process, it was observed that different solutions follow different Zeta functions. To address this problem, a methodology for normalization of captured data between different solutions was created and demonstrated, using the calculated Zeta function and its inverse.

Keywords: biometric signature; calibration; capturing hardware and software; compatibility; digitally captured signature; electromagnetic resonance; forensic handwriting examination; hysteresis; normalization; zeta function.

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References

REFERENCES

    1. Huber R, Headrick A. Handwriting identification: facts and fundamentals. Boca Raton, FL: CRC Press; 1999. p. 135.
    1. Brewster F. Contested documents and forgeries. Calcutta: The Book Company Ltd; 1932. p. 39.
    1. European Network of Forensic Science Institutes. Appendix 5 - Overview procedure for forensic examinations and comparisons of digitally captured signatures and handwritten entries. In: European Network of Forensic Science Institutes, editor. Best practice manual for the forensic examination of handwriting. Version 03. Wiesbaden: ENFHEX; 2020. p. 48-64.
    1. International Organization for Standardization. ISO/IEC 19794 - 7:2014/AMD 1:2015. Biometric data interchange formats - Part 7: signature/sign time series data - amendment 1: XML encoding. Geneva: International Organization for Standardization; 2015.
    1. Kalantzis N. Normalization and comparability of digitally captured signatures (DCS). In: Proceedings of the 73rd Annual Scientific Meeting of the American Academy of Forensic Sciences; 2021 Feb 15-19; held virtually. Colorado Springs, CO: American Academy of Forensic Sciences; 2021. p. 717.

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