利用数字图像处理技术伪造文件的研究

介绍了利用数字图象处理技术剪贴伪造文件、变造签名、彩色打印伪造原始印文和签名等三种伪造文件的方法及其特点.数字图象处理技术能够克服许多传统伪造方法的"缺点",使伪造的文件达到较高的逼真度.讨论了数字图象处理技术的滥用引发的新问题.     

Clothed and unclothed human figure drawings lead to more correct and incorrect reports of touch in children

Abstract

The purpose of the current study was to examine the effect of clothed and unclothed human figure drawings (HFDs) on children's reports of touch. Eighty 4/5-year-olds and 80 9/10-year-olds participated in a staged event in which measurements of their body parts (e.g. waistline) were taken. Specifically, they were touched on 10 different locations. Immediately or three weeks after the event, they had to report where they had been touched. Half of the children received a clothed HFD while the other half was provided with an unclothed HFD to assist children in their recall. When we compared children's recall before and after the presentation of a HFD, we found that clothed and unclothed HFDs significantly decreased the accuracy of children's reports of touch. So, although children reported more correct touches after the presentation of a HFD, they were also more likely to include more incorrect information in their reports of touch.     

Identification of document paper using hybrid feature extraction

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.     

利用暗记特征鉴别彩色激光打印、复印文件

目的探讨激光打印机的暗记特征,为鉴别彩色激光打印、复印文件找到一种有效的方法。方法根据不同物质对光的反射特性及蓝色与黄色互补特性的原理,采用420nm左右蓝光照射方法,对部分品牌彩色激光打印、复印文件进行了初步分析研究,总结了暗记点阵形态特征、小点形态特征、出现位置特征和排列含义等特征。结果此方法对彩色激光打印、复印机具的种类鉴别和个体鉴别简便、有效。     

Evaluation of laser desorption mass spectrometry and UV accelerated aging of dyes on paper as tools for the evaluation of a questioned document

Laser desorption mass spectrometry (LDMS) may be used for the detection and identification of dyes found in inks. Naturally-aged and artificially-aged blue and black ballpoint pen inks containing the cationic dye methyl violet were analyzed on paper. The average molecular weight of the dye sample was calculated from LD mass spectral data and plotted versus time. The resulting aging curves demonstrate that, as dye degradation increases, the average molecular weight of the dye decreases. Typical variables involved in ink aging, such as the type of paper and ink formulation, were investigated. Results show that these variables influence the rate of dye degradation. Furthermore, UV accelerated aging has been developed and tested as an alternative to thermal approaches.     

Implementing statistical learning methods through Bayesian networks (Part 2): Bayesian evaluations for results of black toner analyses in forensic document examination

This paper presents and discusses the use of Bayesian procedures – introduced through the use of Bayesian networks in Part I of this series of papers – for ‘learning’ probabilities from data. The discussion will relate to a set of real data on characteristics of black toners commonly used in printing and copying devices. Particular attention is drawn to the incorporation of the proposed procedures as an integral part in probabilistic inference schemes (notably in the form of Bayesian networks) that are intended to address uncertainties related to particular propositions of interest (e.g., whether or not a sample originates from a particular source). The conceptual tenets of the proposed methodologies are presented along with aspects of their practical implementation using currently available Bayesian network software.     

The viability and possible applications of high resolution mark replicator casting compound in document examination.

Mark replicator casting compounds are commonly associated with recovering toolmark detail. A series of experiments was designed to identify the possible applications, and assess the overall viability, of using mark replicator compound to record indentations on questioned documents. The trials included testing the effect of Isomark High Resolution Mark Replicator on different paper-based substrate types, and observing in particular, any damage that it may cause. The experiments also tested the effect that the mark replicator has on subsequent fingerprinting techniques. It was found that the mark replicator successfully recorded indentations on paper and card surfaces. In some cases, the mark replicator caused staining on some of the surfaces and had a negative effect on the quality of fingerprints subsequently developed.     

Identification of sex depending on radiological examination of foot and patella

Forensic anthropology involves the building of an antemortem profile of an individual from skeletal remains. This includes sex, race determination, and age and stature estimation. Because most bones that are conventionally used for sex determination are often recovered either in a fragmented or incomplete state, it has become necessary to use denser bones that are often recovered intact, eg, the patella, calcaneus, and talus. The present work was performed to investigate the possibility of estimation of sex from some radiologic measurements among a known cross-section of Egyptian population. In this study lateral and anteroposterior radiographs of the right foot and knee were made on 160 living unfractured and nonpathologic individuals comprising 80 males and 80 females aged 25 to 65 years referred to the Radiology Department of Assiut University Hospital. Two measurements on right patella (maximum height and maximum width) and 2 measurements of metatarsal bones (length and midshaft diameter), were used to determine sex by univariate and multivariate discriminant analysis. Eighty radiographs of foot and patella of individuals not used in the original sample were randomly selected to test the accuracy of this method. The study revealed that significant sex differences were demonstrated based on these measurements taken on metatarsal bones more than on patella. One function associating 2 parameters (length and midshaft) of the third metatarsal bone obtained the highest value of correct sex determination with rate of 100% accuracy. The multivariate function associating length of the first, third, and fifth metatarsal bones and midshaft of first, second, and fifth metatarsal gave 100% accuracy. Test of multivariate function on the independent sample revealed a correct classification of 87.5%.     

Discrimination of document paper by XRF, LA–ICP–MS and IRMS using multivariate statistical techniques

The purpose of this study was to evaluate the potential of inorganic analysis techniques for the discrimination of document (multipurpose office) paper. A set of 25 different multipurpose office papers from the European market was used for comparison. It appeared that for the single techniques LA–ICP–MS had the highest overall discriminating power. Despite its lower sensitivity, XRF also showed good discriminating power but the correlation with LA–ICP–MS is high. The combination of LA–ICP–MS and IRMS provides a powerful and strongly discriminating set of techniques.     

Identification of human gender by hand x-ray

A planimetric analysis of hand bones x-ray images is proposed for gender identification. The gender is determined by two methods: by interval estimation of bones size and calculation of the discriminant function and its comparison with group centroid values.     

Identification of mongoose (Genus: Herpestes) species from hair through band pattern studies using discriminate functional analysis (DFA) and microscopic examination

India is home to seven species of mongoose (Herpestes sp). Mongooses are being poached primarily for their hair, which is used in the production of painting and shaving brushes. Prior to September 2002, mongooses were listed under Schedule-IV of the Wildlife (Protection) Act 1972 (India). Indiscriminate poaching of the mongoose created an immediate threat to their survival and hence mongooses have now been placed under Schedule-II of the Wildlife (Protection) Act-1972 (India). In order to convict a person under this legislation, species identification of case related samples is necessary. Four species of mongoose i.e. H. edwardsii, H. smithii, H. palustris and H. urva were characterised by performing discriminate functional analysis (DFA) on measurements of their dorsal guard hair banding pattern and by microscopic hair characteristics (Cuticular, medullar and cross section). It was possible to distinguish between the four species studied, based on both these methods.     

Identification of human urinary stains by enzyme-linked immunosorbent assay for human uromucoid

An enzyme-linked immunosorbent assay (ELISA) of the sandwich type for identification of human urinary stains using commercially available anti-human uromucoid was developed. When experimentally prepared urinary stains of humans and animals, 2 by 2 cm in area, were subjected to analysis, human stains could be differentiated from animal ones except chimpanzee and Old World monkey ones. Stains of other human body fluids showed negative reactions. The reactions did not decrease when human urinary stains were stored at room temperature for three months. The present ELISA provides a useful presumptive test for urinary stains of human origin.     

Investigation of Ballistic Evidence through an Automatic Image Analysis and Identification System

Automated firearms identification (AFI) systems contribute to shedding light on criminal events by comparison between different pieces of evidence on cartridge cases and bullets and by matching similar ones that were fired from the same firearm. Ballistic evidence can be rapidly analyzed and classified by means of an automatic image analysis and identification system. In addition, it can be used to narrow the range of possible matching evidence. In this study conducted on the cartridges ejected from the examined pistol, three imaging areas, namely the firing pin impression, capsule traces, and the intersection of these traces, were compared automatically using the image analysis and identification system through the correlation ranking method to determine the numeric values that indicate the significance of the similarities. These numerical features that signify the similarities and differences between pistol makes and models can be used in groupings to make a distinction between makes and models of pistols.     

Determining the sex of human remains through cranial morphology

Sex determination is the keystone of a biological profile, yet few qualitative methods of cranial sex determination have been tested. This analysis examines the accuracy and precision of 17 morphological features of the skull commonly used to determine the sex of unknown skeletal remains. The sample consists of 46 identified skulls from the 19th century St. Thomas' Anglican Church Cemetery in Belleville, Canada. Nasal aperature, zygomatic extension, malar size/rugosity, and supraorbital ridge proved the most useful; of secondary value are chin form and nuchal crest; mastoid size is of tertiary consideration; nasal size and mandibular symphysis/ramus size rank fourth; forehead shape ranks fifth; and palate size/shape are sixth. Skull size/architecture provides an internal standard to assess the relative sizes of other traits. This research is a necessary step in establishing the credibility of morphological sex determination with respect to the Daubert and Mohan criteria for admissibility in a court of law.