Imagens digitais e quimiometria – uma abordagem em documentoscopia na avaliaçao de tintas de canetas pretas

Abstract

The pen ink analysis on paper is an important area in forensic chemistry that can be used to identify forgeries and alterations in a document. However, many of analytical instrumental methods are expensive and/or destructive, and in this area, document destruction should be avoided whenever possible. Thus, this work proposes the application of the parallel factor analysis (PARAFAC) chemometric tool in digital images obtained from a smartphone (Xiaomi Mi A1) for the non-destructive evaluation of ballpoint, rollerball, gel, and felt tip pen types. The results suggest that a non-destructive evaluation can be performed on a document by using a digital image and the chemometric tool PARAFAC, which showed a distinction between the different pen types. Replicate mode loadings represent a measure of precision in the repeatability level, while R (red), G (green), B (blue) channel loadings show the portion of these channels that influence the separation.