工程图纸识别与智能化光栅矢量编辑系统

该文描述了工程图纸矢量化、识别的处理与实现过程,对当前矢量化中存在的问题进行了分析研究。提出智能化光栅矢量化的方法,采用自动和交互搜索的方法实现光栅信息的提取、编辑和矢量化,并结合知识引导的联想修正技术使识别的准确性有了明显提高。文中结合建筑结构图的自动识别和计算进行了研究。     

工程图纸的矢量化方法

矢量化是工程图纸自动输入和识别不可缺少的重要环节。而线段提取则是矢量化处理的关键。本文拟对工程图纸矢量化过程中图象预处理和常用的几种线段提取方法作一简要介绍和比较,同时对所用的处理给出算法描述。     

浅谈CASSCAN5.0软件在地形图扫描矢量化中的应用

CASSCAN5.0软件具有强大的图像处理功能,支持全自动矢量化和交互式自动跟踪,因此,本文介绍了如何利用CASSCAN5.0软件对扫描地形图进行交互式矢量化。通过实例证明,使用CASSCAN5.0软件进行扫描矢量化,不仅能提高矢量化效率,而且能满足精度要求。     

基于可变形模型及区域流向分析的等高线自适应矢量化算法

等高线的矢量化一直是地形图自动识别的难点之一．该文对目前图纸矢量化算法进行了总结分析，根据等高线本身所具有的特征，结合人眼对等高线跟踪提取的特点，提出可变形模型跟踪矢量化算法．算法通过初始种子段的生成、可变内力控制及区域流向分析，直接在原地形图上实现等高线的自动矢量化及断点、粘连点的处理．实验证明该方法行之有效且具有很好的稳定性．     

基于细化和自适应网格的图纸矢量化方法

文中提出了一种基于细化和自适应网格相结合的矢量化方法。该方法将局部矢量化与全局矢量化结合起来，既具备了基于细化方法进行图纸矢量化的优点，同时又可以利用自适应网格技术提取交叉处矢量以避免畸变的产生。     

基于OTSU和轮廓追踪的地图线条识别方法

纸质地图或扫描地图是传统地图保存方式。这种方式使得空间查询与分析困难,需要将这些地图矢量化才有助于对历史地理空间数据的查询和分析。然而,传统矢量化方式耗时耗力,不能满足实际需求。为此,提出了一种基于边界追踪的地图自动矢量化方法。首先,将地图灰度化和二值化;然后,对二值化的地图应用栅格转矢量方法矢量化。最后,基于4幅地图,测试了本文方法的提取效果。实验结果表明,本文方法能够较为完整地提取出全部地图的线条,且可以有效地将地图中的文字分离出来。     

数字地图局部自动生成与半自动编辑

数字地图的局部自动生成与半自动编辑系统由道路编辑模块和房屋编辑模块构成。文章详细描述了各模块中的半自动提取功能的算法，其中道路提取采用了滚球法，房屋提取采用的是基于几何关系的算法。所有半自动提取算法都在图形的基础上操作的，能保证有较好的通用性，不仅可用于纸面地图生成数字地图的开发过程，而且适用于从航空图像开发数字地图等用途。数字地图半自动编辑器已可作为一个独立的系统，在人机交互状态下自动／半自动生成数字道路地图和数字房屋地图。     

矢量化在切绘机自动编程系统中的应用

研究了图像矢量化的关键技术,并将其应用到数控切绘机自动编程系统中.系统的输入为衣服、鞋帽等样片的扫描图,通过中值滤波、二值化、边缘提取、轮廓跟踪和曲线拟合等处理,实现了样片轮廓信息的矢量化.这种方法的应用扩展了数控切绘机自动编程系统的造型功能,增强了切绘机的适用性.     

一种快速的扫描铅笔稿图细化算法

二维动画计算机输助制作系统中,在对扫描铅笔稿图进行矢量化后,可以大大提高描线上色的效率,并且能够提取线条和闭包,对便于自动上色和中间帧生成等更高级功能的实现。扫描铅笔搞图的细化是矢量化的第一步,在比较了大量现存的图象细化算法后,提出了一种非迭代线跟踪细化算法,该算法效率较高,只需对图象进行一遍扫描加两遍轮廓跟踪,就能较好地满足二维动画计算机辅助制作系统对细化效率的要求。该文还对算法的时间复杂性进行     

矢量字库的设计与实现

矢量字库是使用矢量文字的主要方式。本文以一种轮廓文字位图矢量化的方法为基础，详细介绍了从文字住图数据抓取、位图轮廓提取、矢量化数据生成、到矢量化字库生成、读取及显示的设计与实现方法。     

Detecting conjugate-point pairs for map alignment between two polygon datasets

When the same objects in different datasets have different positions and shapes, map alignment is necessary to minimise these geometric inconsistencies for successful map integration. In this paper, we propose a method to detect conjugate-point pairs for aligning two polygon datasets by matching the contours of corresponding polygons. This method comprises three processes, including identification of the corresponding polygon pairs, shape approximation with virtual corner-vertices and detection of conjugate-point pairs with our modified vertex-attributed-string-matching (VASM) algorithm. We applied this method to two distinct spatial datasets; a cadastral map and a topographical map of the same urban area. Then, the performance of our method was assessed visually and statistically. Both evaluations showed satisfactory results.     

Challenges of land administration and Bolivian colonization: beyond technical cadastral mapping

The paper provides an overview of the dynamic process of concluding land-titling efforts started almost 30 years ago in a colonization area of Bolivia. Through the course of the cadastral mapping effort it was discovered that technological solutions cannot stand alone as the answer to land administration challenges. Findings demonstrated failings that can occur in land information systems attributed largely to an over confidence in standardization and technology as well as a lack of information or attention to detail about local land tenure characteristics, illustrating the adage that land is unique. This paper focuses on the lessons learned through public participation in the parcel mapping of 100 colonies subjected to titling and certification. Mechanisms that strengthen the tenants' role in the cadastral mapping process proved mutually beneficial to both tenants and technicians by streamlining the process. Getting initial input into the process during the information-gathering stage rather than simply submitting the results for criticism after the fact avoided duplication of efforts thus improving the efficiency of the land administration project. Efficiency is increased while empowering those most interested in the work. The lessons learned here may be exported to other cadastral mapping projects.     

动态土地信息系统时空过程及时空数据存储

时态GIS（TGIS）以及时空数据模型是当前地理信息科学领域的研究热点，土地地籍管理信息系统是TGIS的典型应用，对土地地籍管理信息系统的时空过程进行了分析；提出了在基态修正时空数据模型中，采用区段快速索引和变粒度存储因子方法；通过区段快速索引和变粒度存储因子的引入，系统查询效率有了明显提高；论述了土地信息系统中的时空概念，数据结构和系统实现，重点讨论了数据库中的数据组织、拓扑关系建立及数据存储管理机制；最后介绍了基于上述模型和方法开发的新一代大型网络级动态土地地籍管理信息系统（ReGIS）的主要功能，两年多的应用表明，系统设计先进，性能良好，运行稳定。     

Transition from 2D to 3D real property cadastre: The case of the Slovenian cadastre

The land administration system, providing a mechanism to support the management of real properties, is one of the most crucial infrastructures of any country. This infrastructure is needed to support planning and implementation of land-related policies, and in general to support human decisions and activities in our environment. The fundamental part of a modern land administration system is the land cadastre. Over the last decade, the demand for three-dimensional (3D) cadastre has increased significantly worldwide. The physical and legal complexities of the built and natural environment prompt new concepts and definitions of real property units in order to meet the demands of a today's society and to balance private and public spatial interests. Particularly in urban areas, including other areas with intensive human interventions into space, there is a tendency to use space above and below the Earth's surface, above and below structures, etc. Complex 3D objects cannot be defined and registered as cadastral objects in the traditional 2D land cadastre and represented in a 2D cadastral map. For this purpose, next to the land cadastre, in 2000, Slovenia introduced the building cadastre. From the juridical point of view, the current cadastral system is not sufficient for all 3D situations. In this paper, we discuss upgrade possibilities of data models of the land cadastre and building cadastre to introduce a unique 3D real property cadastre in Slovenia. We believe that the data available in the current cadastres will significantly contribute toward the 3D real property cadastre and 3D graphical representation of cadastral data; nevertheless, some additional data are needed. The minimum data required could be provided already through the current cadastral procedures.     

Attention-based multi-modal fusion for improved real estate appraisal: a case study in Los Angeles

Multimedia Tools and Applications - The geographical presentation of a house, which refers to the sightseeing and topography near the house, is a critical factor to a house buyer. The street map is...     

Structuring urban data

Geometric city modeling is an open problem without standard solutions. Within this problem, there appear several sub-problems that must be faced, like the accurate modeling of streets, buildings and other architectonic structures. One important source of geographical information is (measured) cadastral urban data. However, this information is not always well structured, and sometimes it is even simply corrupted GIS data. In this paper we present a robust and generic solution for the generation of block and building layouts based on a repairing process applied when this data is not correct. Our input data is a top projection map of a city which usually has been created by a mixture of photogrammetric restitution and, in a second stage, hand-drawn using any GIS application. Moreover, these maps are under continuous modifications, like in the case of public administrations. This process sometimes results in the introduction of mistakes and anomalies, which are hard to correct without the appropriate tools. Our solution is based on a novel semi-automatic 2D restructuring algorithm, which uniformly corrects errors and ambiguities that are commonly present in corrupted cadastral data. This problem is complex because it is necessary to identify not just simple elements from the input file, but also their connectivity and structure in the real world. The output of our algorithm is the urban data restructured into a hierarchy of blocks and buildings, from which we can get a realistic 3D model by extruding each building using the floor number for each building within the cadastral data.     

地籍空间数据库拓扑关系分析及基于规则的验证方法

为了提高空间数据质检的效率，实现要素类间拓扑关系的智能检测，在分析地籍空间数据库要素拓扑关系分类的基础上，提出了基于拓扑规则的拓扑关系验证方法，并采用GIS开发平台ArcEngine，开发了空间数据质检系统LR_Checker。大量地籍空间数据的测试表明，采用LR_Checker可大大降低数据检查的工作量，基于拓扑规则的拓扑关系验证方法是正确、有效和合理的。     

Cadastral systems — alternatives

The importance of successful cadastral systems to a country's economy, administration and rule of law are accepted by many. Several donor organizations have been, for quite some time, supportive of projects to make existing cadastral systems more successful or set up new ones. Nevertheless, there have been, and still are, problems with such projects. One of the reasons for such problems relates to the limited cadastral knowledge of local experts and to the fact that many foreign consultants are mainly familiar with the cadastral system of their own country. It is important for all the cadastral experts, whether they are local or foreign, to know that there are many alternatives, which in general, give a good solution. The article will introduce the most common alternatives for seven issues, like a centralized or decentralized cadastral system, land registration with a separate or integrated cadastre, and different parcel identification methods. Even though there seems to be little correlation between the alternatives used in a particular country and the question of whether its cadastral system is running well, the article ends with some conclusions based on our recent experiences in central Europe.