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The evaluation and classification of chemical properties in different copy-paper products could significantly help address document forgery. This study analyzes the feasibility of utilizing infrared spectroscopy in conjunction with machine learning algorithms for classifying copy-paper products. A dataset comprising 140 infrared spectra of copy-paper samples was collected. The classification models employed in this study include partial least squares-discriminant analysis, support vector machine, and K-nearest neighbors. The key findings indicate that a classification model based on the use of attenuated-total-reflection infrared spectroscopy demonstrated good performance, highlighting its potential as a valuable tool in accurately classifying paper products and ensuring assisting in solving criminal cases involving document forgery.

The evaluation and classification of chemical properties in different copypaper products could significantly help address document forgery. This study analyzes the feasibility of utilizing infrared spectroscopy in conjunction with machine learning algorithms for classifying copy-paper products. A dataset comprising 140 infrared spectra of copy-paper samples was collected. The classification models employed in this study include partial least squares-discriminant analysis, support vector machine, and K-nearest neighbors. The key findings indicate that a classification model based on the use of attenuated-total-reflection infrared spectroscopy demonstrated good performance, highlighting its potential as a valuable tool in accurately classifying paper products and ensuring assisting in solving criminal cases involving document forgery. [ABSTRACT FROM AUTHOR]

Recently, in forensic science studies, identification of the source of color laser printouts is one of the most challenging issues that hinder forensic document examiners. Although various methods for establishing the identity of the source of color laser printouts are currently available worldwide, none of those methods approaches an accuracy and precision of 100%. The coded dot matrix patterns are state-of-the-art prototypes of steganography based on the active technique. Upon tracking the coded dot matrix patterns of all investigated color laser printouts, the identity and uniqueness can be determined, respectively. In the current paper, nineteen variant brands of color laser printer machines were selected. The advanced security features embedded in their printouts have steganalysis and grouped them into two broad categories. A direct model of hyperspectral analysis integrated with video spectral comparator Regula® 4307 was applied. The complete identification of the investigated color laser printouts was achieved. The decisive degree of the results reached one hundred percent for the investigated color laser in this study. Moreover, the novel classification scheme of coded dot matrix patterns presents for completing the individual characteristics.

Document forgery is a significant issue in Korea, with around ten thousand cases reported every year. Analyzing paper plays a crucial role in examining questionable documents such as marketable securities and contracts, which can aid in solving criminal cases of document forgery. Paper analysis can also provide essential insights in other types of criminal cases, serving as an important clue for solving cases such as the source of a blackmail letter. The papermaking process generates distinct forming fabric marks and formations, which are critical features for paper classification. These characteristics are observable under transmitted light and are created by the forming fabric pattern and the distribution of pulp fibers, respectively. In this study, we propose a novel approach for paper identification based on hybrid features. This method combines texture features extracted from images converted using the gray‐level co‐occurrence matrix (GLCM) approach and a convolutional neural network (CNN), with another set of features extracted by the CNN using the same images as input. We applied the proposed method to classification tasks for seven major paper brands available in the Korean market, achieving an accuracy of 97.66%. The results confirm the applicability of this method for visually inspecting paper products and demonstrate its potential for assisting in solving criminal cases involving document forgery. [ABSTRACT FROM AUTHOR]

In forensic document analysis, the authenticity of a document must be properly checked in the context of suspected forgery. Hyperspectral Imaging (HSI) is a non-invasive way of detecting fraudulent papers in a multipage document. The occurrence of a forged paper in a multi-page document may have a substantial difference from rest of the papers in its age, type, color, texture, and so on. Each pixel in an HSI data can be used as the material fingerprint for the spatial point it corresponds to. Hence, hyperspectral data of paper samples made of the same substance have similar characteristics and can be grouped into a single cluster. Similarly, paper samples made of different substances have different spectral properties. This paper relies on this heuristic and proposes a tensor based clustering framework for hyperspectral paper data, with an application to detect the forged papers in multi-page documents. Information embedded in the hyperspectral patches of the papers to be clustered is arranged into individual lateral slices of a third-order tensor in this framework. Further, this work employs the self-expressiveness property of submodules and an objective function is formulated to extract self-expressive representation tensor with low multirank and f-diagonal structure. Objective function of the proposed method incorporates $l_{\frac {1}{2}}$ -induced Tensor Nuclear Norm (TNN) and $l_{\frac {1}{2}}$ regularization to impart better low rankness and f-diagonal structure to the representation tensor. Experimental results of the proposed method were compared to the state-of-the-art subspace clustering approaches. The results demonstrate improved performance of the proposed method over the existing clustering algorithms.

The article addresses the problems of methodical support for establishing the statute of limitations when conducting a forensic document examination, directly affecting the admissibility of an expert’s opinion as evidence in legal proceedings. Establishing the statute of limitations for the execution of documents’ requisites is one of the most demanded tasks when considering all categories of cases – administrative, arbitration, civil, criminal. Analysis of the forensic practice of this type of examination in legal proceedings shows the application of various methods and approaches. Such variety raises questions among both the judicial and legal communities. For example, what existing methods are scientifically substantiated, tested, certified, lead to reliable results, and can be used to solve expert tasks? Which are unsuitable for the use in expert practice, and for what reasons?To confirm the suitability of their author’s developments for forensic examination, individual non-state experts provide various patents and certificates. How legal and permissible is this practice?The article offers a competent analysis of the current situation on the example of the widely used method of “wet copying”