A Computer-Based System to Support Forensic Examination of Japanese Documents

该研究项目已进行了两年（2001-2002年）。本研究项目的目的是开发一个基于计算机的系统，以支持日本文件的法医检查。我们能够达到这个研究项目的目的。研究项目取得的成果摘要如下。(1)我们已经开发了一个交互式的笔迹比较图表的准备系统，以支持日本的法医文件分析。该系统由三个主要的处理模块组成：（1）笔迹提取模块，用于从文档中分割成分笔迹;（2）手写字符识别模块，用于识别分割的笔迹以有效地制备图表;（3）图表制备模块，用于显示被质疑和已知文档的相同种类的笔迹以便于比较。每个模块都是与用户交互的，并且是菜单和鼠标驱动的。原型系统已在WindowsXP操作系统下用C++Builder实现。通过实例分析，证实了该系统比传统的海图制作方法更快、更有效。(2)我们已经开发了一种计算机算法，半自动地提取笔迹特征。提取的特征是笔画结构，如笔画长度比、两个笔画之间的交叉角度等。这些是文档审查员用于审查日文笔迹的许多特征中最重要的特征。为了验证个性的笔迹，我们研究这些功能的变化在一个人的笔迹样本和不同的人的笔迹样本之间。通过对笔迹特征的分析，验证了笔迹的个性特征，并进一步增加笔迹特征分析功能，以提高系统的支持功能。

This research project has been carried out over two years (2001-2002). The aim of this research project is to develop a computer-based system to support forensic examination of Japanese documents. We were able to achieve the aim of this research project. The summary of results obtained by the research project is as follows.(1) We have developed an interactive preparation system of handwriting comparison charts to support Japanese forensic document analysis. This system consists of three major processing modules ; (1) handwriting extraction module for segmenting component handwritings from documents, (2) handwritten character recognition module, which recognizes segmented handwritings for efficient preparation of charts, (3) chart preparation module, which displays the same kinds of handwritings of both questioned and known documents for easy comparison. Every module works interactively with user, and is menu and mouse driven. The prototype system has been implemented using C++Builder under WindowsXP operating system. Though some case studies, it was confirmed that this system is faster and more effective than traditional method in preparing charts.(2) We have developed a computer algorithm, which extracts features of handwriting semi-automatically. Extracted features were stroke structures such as length ratio of strokes, crossing angles between two strokes, etc. These are most important features of many features, which document examiners have used for examining Japanese handwritings. To validate individuality of handwriting, we examine the variation of these features within a person's handwriting samples and between the handwriting samples of different people. Through the analysis, we were able to validate the individuality of handwriting.It is the future work to add the feature analysis function to this system to improve the supporting function of this system.