【作者】 刘平；

【导师】 廖兆存；

【作者基本信息】 华中科技大学 ， 计算机应用技术， 2007， 硕士

【摘要】 PDF擅长于描述复杂的页面版式,因此已经成为通用文档格式标准之一,也是目前最常用的科技论文存储载体。而ScienceWord是一种面向科技教育领域的专业文档处理软件,可以方便地编辑公式、化学式、数学几何图形等科技文档对象。然而ScienceWord格式文档尚不具有很强的通用性,为了满足用户需求,有必要向ScienceWord软件中加入PDF存储功能。PDF文档存储模块开发相对独立于ScienceWord软件框架。从功能上来看,该模块所做的主要工作可分为两部分:文字、图形、图片等基本文档对象的加入;科技文档对象的加入。基本文档对象在PDF中以页面描述语言形式描述,同时兼顾生成PDF的文档精确性、存储效率以及跨平台特性。科技文档对象则相对复杂,除了构成自身的基本文档元素以外,它们不仅具有复杂的内部结构,而且不同科技文档对象之间也具有复杂的逻辑关系。这些逻辑信息是用户最为关心的,也是传统PDF文档不能描述的。为了减小在文档存储过程中逻辑信息的损失,得到具有更好内容访问特性的PDF文档,对科技文档对象描述进行了研究,将其抽象为层次化的数据结构,然后通过扩展的PDF标签描述。以研究结果为依据实现的原型系统与ScienceWord软件框架兼容,可以作为ScienceWord软件中的PDF文档存储方案。原型系统生成的标签PDF文件可以完全保持文档原有的逻辑信息,并且可以通过Acrobat插件程序提取还原这些信息。标签PDF文档可以描述复杂的文档逻辑结构,而且页面内容的物理存储更有组织,便于今后实现基于内容的PDF文件检索或是其他复杂应用。更多还原

【Abstract】 PDF, one of the best choices for describing complex layout, has become a de facto industry standard, and is frequently used for scientific paper storage. ScienceWord, a professional scientific document word processor, can easily edit papers integrated with document objects of science, such as formulas, chemistry equations and geometry shapes. However, document format of ScienceWord hasn’t been universally used yet, so it’s necessary to add PDF storage module to ScienceWord to meet users’needs.The PDF storage module is independent from ScienceWord development framework. From a functionality perspective, there’re 2 types of components in the storage module: components for basic document elements, such as texts, figures and images etc; components for document objects of science. In the previous components, basic document elements are described using Page Description Language in PDF file. At the same time, all the factors, which affect the generated PDF files, should be taken into consideration, like layout displaying accuracy, storage efficiency and platform independence. However, the latter components are more difficult to be implemented because of the complex logical information contained in document objects of science. Unfortunately this type of information can’t be described in average PDF files. In order to decrease the information loss during storage, logical information are abstracted into structured expression, and then translated into logical trees in PDF through defining new PDF tags. The prototype system, which is implemented on the study results, can be used as a PDF storage solution due to its compatibility with ScienceWord frameworks. According to the test, all structured logical information can be expressed exactly, and then extracted truly through Acrobat plug-ins in the tagged PDF file generated by the prototype system.Since the entire page contents are well organized, it’s easily expected that these tagged PDF files have got more advanced features. Also they will be helpful for future development of PDF file retrieval and other applications.更多还原