图像检索技术研究进展

近年来,互联网上视觉数据呈现出爆炸式的增长,越来越多的研究工作围绕图像搜索或图像检索技术而展开.早期的搜索技术仅采用文本信息,忽视了视觉内容作为排序的线索,导致搜索文本和视觉内容不一致.基于内容的图像检索（CBIR）技术充分利用视觉内容识别相关图像,在近几年来获得了广泛关注.在图像检索中,最根本的问题是意图鸿沟和语义鸿沟,围绕该问题,近年涌现出大量的基于内容的图像检索的技术.本文主要对2003-2016年间提出的相关图像检索方法进行总结、分类和评估,并对未来的潜在研究方向进行讨论.     

地图图形目标之间基本空间关系抽象的规律

以地图自动综合为目的,定义了空间目标的几种基本空间关系.总结了道路、水系、居民地等要素之间存在的典型空间关系,着重讨论了它们之间空间关系抽象的规则,为地图自动综合中有效保持空间关系的一致性提供必要的理论基础.     

重叠矩形图像表示及其上的精确Legendre矩计算(英文)

Linear quadtree is a popular image representation method due to its convenient imaging procedure. However, the excessive emphasis on the symmetry of segmentation, i.e. dividing repeatedly a square into four equal sub-squares, makes linear quadtree not an optimal representation. In this paper, a no-loss image representation, referred to as Overlapped Rectangle Image Representation （ORIR）, is presented to support fast image operations such as Legendre moments computation. The ORIR doesn＇t importune the symmetry of segmentation, and it is capable of representing, by using an identical rectangle, the information of the pixels which are not even adjacent to each other in the sense of 4-neighbor and 8-neighbor. Hence, compared with the linear quadtree, the ORIR significantly reduces the number of rectangles required to represent an image. Based on the ORIR, an algorithm for exact Legendre moments computation is presented. The theoretical analysis and the experimental results show that the ORIR-based algorithm for exact Legendre moments computation is faster than the conventional exact algorithms.     

Unveiling movement uncertainty for robust trajectory similarity analysis

Trajectory data analysis and mining require distance and similarity measures, and the quality of their results is directly related to those measures. Several similarity measures originally proposed for time-series were adapted to work with trajectory data, but these approaches were developed for well-behaved data that usually do not have the uncertainty and heterogeneity introduced by the sampling process to obtain trajectories. More recently, similarity measures were proposed specifically for trajectory data, but they rely on simplistic movement uncertainty representations, such as linear interpolation. In this article, we propose a new distance function, and a new similarity measure that uses an elliptical representation of trajectories, being more robust to the movement uncertainty caused by the sampling rate and the heterogeneity of this kind of data. Experiments using real data show that our proposal is more accurate and robust than related work.     

Ontologies and representation spaces for sketch map interpretation

In this paper, we present a systematic approach to sketch map interpretation. The method decomposes the elements of a sketch map into a hierarchy of categories, from the material sketch map level to the non-material representational sketch map level, and then interprets the sketch map using the five formal representation spaces that we develop. These spaces (set, graph, metric and Euclidean) provide a tiered formal representation based on standard mathematical structures. We take the view that a sketch map bears information about the physical world and systematises this using extensions of existing formal ontologies. The motivation for this work is the partially automatic extraction and integration of information from sketch maps. We propose a set of ontologies and methods as a first step in the direction of a formalisation of partially automatic extraction and integration of sketch map content. We also see this work as a contribution to spatial cognition, where researchers externalise spatial knowledge using sketch mapping. The paper concludes by working through an example that demonstrates the sketch map interpretation at different levels using the underlying method.     

线状要素移位的研究

制图综合常要求将地形图要素从其正确的图面位置偏移一点。本文就线状要素的移位问题进行讨论。首先提出移位场的概念,这对于由于移位所产生的“连锁反应”能较好地解决;然后,提出一种栅格探测——矢量计算方祛,加快移位计算的速度。     

科尔沁典型沙区专题图形库系统的建立及查询设计

以建立沙漠化环境信息系统核心问题之一的专题图形库为出发点,对利用ＵＴｅｋ工作站及微机建立沙漠化专题图库的技术进行了探讨。建立了科尔沁典型沙区土地结构类型三个时期两级专题图形库,并对库信息的查询方法作了较详细的介绍。     

基于样条函数对线状目标矢量化的表示

在分析遥感影像中提取的线状目标的基础上,利用样条插值函数,对提取的线状目标矢量化表示进行了研究。主要过程包括目标的分解、插值点的选取、插值函数的选择、特征点的增加等。实验结果表明,提出的方法能有效地表示提取的线状目标,减少数据冗余,具有好的光滑性。     

基于GIS的静态图式表达方法与制图表达方法的对比分析

针对GIS生成的地图产品脱离GIS地理空间数据,割裂地理要素与地图对象完整性,导致输出地图产品更新困难。结合制图单位实际生成需求,研究GIS静态图式表达和GIS制图表达;基于GIS制图模板和GIS符号库,采用C#+ArcEngine编程技术,实现GIS专题制图系统。系统具有GIS静态图式渲染功能和GIS制图表达功能,并以某区域专题制图项目为例,对比分析不同方式专题制图效果。结果表明基于地理空间数据规则的地图制图表达技术能够兼顾GIS和地图制图对数据的不同要求,可快速完成地图制作,部分解决传统上必须通过大量人工编辑才能够完成的制图任务,一定程度提高工作效率。     

高光谱图像稀疏信息处理综述与展望

高光谱成像技术具有光谱连续、图谱合一,能够以较高的光谱诊断能力对地物目标进行精细化解译,可以大幅增强地物信息的提取能力。充分利用高光谱遥感图像丰富的空间、谱信息,进行观测目标地物的精细化解译,成为近年来遥感领域的研究热点和前沿领域,并在多个相关领域具有巨大的应用价值和广阔的发展前景。本文结合高光谱图像成像特点,对基于稀疏表示理论的高光谱图像处理与分析方法进行综述,概括了高光谱图像处理与分析主要研究,并对各个研究领域与方向进行分析和评价,最后对各研究领域发展提出建议和展望。