图像自动语义标注技术综述

近年来,随着对基于内容图像检索技术研究的深入,图像自动语义标注已成为了该领域的研究热点。针对目前广泛研究的图像语义标注技术,从其分类、关键技术、存在问题及发展方向进行了进行了论述,以期为从事该方向研究的人员提供一定的借鉴意义和参考价值。     

图像语义自动标注及其粒度分析方法

缩小图像低层视觉特征与高层语义之间的鸿沟, 以提高图像语义自动标注的精度, 进而快速满足用户检索图像的需求,一直是图像语义自动标注研究的关键. 粒度分析方法是一种层次的、重要的数据分析方法, 为复杂问题的求解提供了新的思路. 图像理解与分析的粒度不同, 图像语义标注的精度则不同, 检索的效率及准确度也就不同. 本文对目前图像语义自动标注模型的方法进行综述和分析, 阐述了粒度分析方法的思想、模型及其在图像语义标注过程中的应用, 探索了以粒度分析为基础的图像语义自动标注方法并给出进一步的研究方向.     

基于个性化本体的图像语义标注和检索

针对目前图像检索系统较难实现语义检索的问题,提出了一种新的以本体为核心的图像语义标注和检索模型。构建个性化本体描述图像语义,继而提取基于概念集的图像语义特征并利用本体中“Is-A”关系设计相似性度量方法最终实现语义扩展检索。其难点在于顶级本体向个性化本体进化,以及基于概念集和“Is-A”关系实现语义相似度量的方法。通过系统的初步实现与相关实验的验证,该模型的检索准确度可达88.6%,明显高于传统的基于关键字和基于通用本体的图像检索,实现了图像智能检索功能。     

基于语义分类的文物图像标注研究

由于图像数据中普遍存在的“语义鸿沟”问题，传统的基于内容的图像检索技术对于数字图书馆中的图像检索往往力不从心。而图像标注能有效地弥补语义的缺失。文中分析了图像语义标注的现状以及存在的问题，提出了基于语义分类的文物语义标注方法。算法首先通过构建一个Bayes语义分类器对待标注图像进行语义分类，进而通过在语义类内部建立基于统计的标注模型，实现了图像的语义标注。在针对文物图像进行标注的实验中，该方法获得了较好的标注准确率和效率。     

基于语义分类的文物图像标注研究

由于图像数据中普遍存在的“语义鸿沟”问题,传统的基于内容的图像检索技术对于数字图书馆中的图像检索往往力不从心。而图像标注能有效地弥补语义的缺失。文中分析了图像语义标注的现状以及存在的问题,提出了基于语义分类的文物语义标注方法。算法首先通过构建一个Bayes语义分类器对待标注图像进行语义分类,进而通过在语义类内部建立基于统计的标注模型,实现了图像的语义标注。在针对文物图像进行标注的实验中,该方法获得了较好的标注准确率和效率。     

基于内容检索的图像自动标注方法研究

图像标注技术是近年来的研究热点。为了更好地解决图像自动标注问题,提出了一个基于检索和重排序的标注方法。在检索阶段,通过使用基于MSF的全局特征对待标注图像进行基于内容的检索,从而在图像数据库中得到一系列的相似图像数据集;在重排序阶段,利用随机漫步方法对相似图像数据集的标注信息进行重排序,最终排序后的关键词则为待标注图像的标注信息。该方法不仅跳过了漫长的训练阶段,而且充分利用了网络上那些已经具有标注信息的图像,具有较好的稳定性和可扩展性。实验结果显示了该方法的有效性。     

CAD模型自动语义标注

为了解决基于关键字检索方式难以获得符合设计意图的CAD模型的问题,通过对CAD模型自动添加语义标签来改进传统关键字方式检索CAD模型的准确性.首先提出一种利用属性图比较CAD模型形状相似性的算法,根据图的邻接矩阵及顶点属性构造图顶点集的序列,通过动态编程方法求出图的最大公共子图,得到CAD模型之间的形状相似度;然后根据求出的未知模型与已知模型之间的形状相似度,利用概率方法实现对未知模型的自动语义标注.实验结果表明,采用文中方法可以使基于关键字的检索方法具有搜索形状相似模型的功能,在很大程度上改进了传统关键字方式检索CAD模型的准确性.     

结合SML与本体的图像语义自动标注方法

图像语义自动标注成为基于内容的图像检索研究的热点,提出一种改进的SML两级图像语义自动标注方法.首先采用监督多类标注方法 SML对图像进行粗略标注,然后用基于本体的最优语义标注方法(Oostia)对粗略标注的结果进行精细标注,Oostia方法通过4种不同方式对粗略标注关键字进行扩展,充分挖掘图像中丰富的语义信息.文中提出的方法与其它相关方法进行了比较,实验结果表明,该方法优于其它方法.     

融合语义主题的图像自动标注

由于语义鸿沟的存在,图像自动标注已成为一个重要课题.在概率潜语义分析的基础上,提出了一种融合语义主题的方法以进行图像的标注和检索.首先,为了更准确地建模训练数据,将每幅图像的视觉特征表示为一个视觉"词袋";然后设计一个概率模型分别从视觉模态和文本模态中捕获潜在语义主题,并提出一种自适应的不对称学习方法融合两种语义主题.对于每个图像文档,它在各个模态上的主题分布通过加权进行融合,而权值由该文档的视觉词分布的熵值来确定.于是,融合之后的概率模型适当地关联了视觉模态和文本模态的信息,因此能够很好地预测未知图像的语义标注.在一个通用的Corel图像数据集上,将提出的方法与几种前沿的图像标注方法进行了比较.实验结果表明,该方法具有更好的标注和检索性能.     

一种新的图像语义自动标注与检索算法*

提出了一种新的利用图像语义词汇表进行图像自动标注与检索的方法.采用混合层次模型在已标注好的训练图像集上计算图像区域类与关键字的联合概率分布,并用生成的模型标注未曾观察过的测试图像集,或用来进行基于语义的图像检索.实验结果表明,该方法在标注、检索精度和效率方面均优于当前其他方法.     

CBIR中的索引技术综述

总结了基于内容图像检索中索引技术的研究现状、分析比较了其性能的主要差异，同时也指出了其中存在的问题以及今后的发展趋势．     

Spatial Color Indexing and Applications

We define a new image feature called the color correlogram and use it for image indexing and comparison. This feature distills the spatial correlation of colors and when computed efficiently, turns out to be both effective and inexpensive for content-based image retrieval. The correlogram is robust in tolerating large changes in appearance and shape caused by changes in viewing position, camera zoom, etc. Experimental evidence shows that this new feature outperforms not only the traditional color histogram method but also the recently proposed histogram refinement methods for image indexing/retrieval. We also provide a technique to cut down the storage requirement of the correlogram so that it is the same as that of histograms, with only negligible performance penalty compared to the original correlogram.We also suggest the use of color correlogram as a generic indexing tool to tackle various problems arising from image retrieval and video browsing. We adapt the correlogram to handle the problems of image subregion querying, object localization, object tracking, and cut detection. Experimental results again suggest that the color correlogram is more effective than the histogram for these applications, with insignificant additional storage or processing cost.     

Multi-Modal Dialog Scene Detection Using Hidden Markov Models for Content-Based Multimedia Indexing

A class of audio-visual data (fiction entertainment: movies, TV series) is segmented into scenes, which contain dialogs, using a novel hidden Markov model-based (HMM) method. Each shot is classified using both audio track (via classification of speech, silence and music) and visual content (face and location information). The result of this shot-based classification is an audio-visual token to be used by the HMM state diagram to achieve scene analysis. After simulations with circular and left-to-right HMM topologies, it is observed that both are performing very good with multi-modal inputs. Moreover, for circular topology, the comparisons between different training and observation sets show that audio and face information together gives the most consistent results among different observation sets.     

Two-dimensional entropy model for video shot partitioning

A shot presents a contiguous action recorded by an uninterrupted camera operation and frames within a shot keep spatio-temporal coherence. Segmenting a serial video stream file into meaningful shots is the first pass for the task of video analysis,content-based video understanding. In this paper,a novel scheme based on improved two-dimensional entropy is proposed to complete the partition of video shots. Firstly,shot transition candidates are detected using a two-pass algorithm: a coarse searching pass and a fine searching pass. Secondly,with the character of two-dimensional entropy of the image,correctly detected transition candidates are further classified into different transition types whereas those falsely detected shot breaks are distinguished and removed. Finally,the boundary of gradual transition can be precisely located by merging the characters of two-dimensional entropy of the image into the gradual transition. A large number of video sequences are used to test our system performance and promising results are obtained.     

一类规范文本篇章结构的自动标引

本文通过对汉语文本中标题和段的级、标题的型等概念的描述与分析,讨论了汉语文本篇章结构的标引问题,提出了规范文本的概念,并给出了规范文本篇章结构的一种标记方法,在此基础上,讨论并实现了规范文本篇章结构的自动标引,给出了标引算法。     

Access to Pictorial Material: A Review of Current Research and Future Prospects

Rapid expansion in the digitization of image and image collections has vastly increased the numbers of images available to scholars and researchers through electronic means. This research review will familiarize the reader with current research applicable to the development of image retrieval systems and provides additional material for exploring the topic further, both in print and online. The discussion will cover several broad areas, among them classification and indexing systems used for describing image collections and research initiatives into image access focusing on image attributes, users, queries, tasks, and cognitive aspects of searching. Prospects for the future of image access, including an outline of future research initiatives, are discussed. Further research in each of these areas will provide basic data which will inform and enrich image access system design and will hopefully provide a richer, more flexible, and satisfactory environment for searching for and discovering images. Harnessing the true power of the digital image environment will only be possible when image retrieval systems are coherently designed from principles derived from the fullest range of applicable disciplines, rather than from isolated or fragmented perspectives.     

一种基于二维隐马尔可夫模型的图像分类算法

针对图像分块之间的相互依赖关系,提出一种基于二维隐马尔可夫模型的图像分类算 法。该算法将一维隐马尔可夫模型扩展成二维隐马尔可夫模型,模型中相邻的图像分块在平面两个 方向上按条件转移概率进行状态转换,反应出两个维上的依赖关系。隐马尔可夫模型参数通过期望 最大化算法(EM)来估计。同时,本文利用二维Viterbi算法,在训练隐马尔可夫模型的基础上,实现 对图像进行最优分类。文件图像分割的应用表明,隐马尔可夫算法优于CART算法。     

A New Indexing Scheme for Content-Based Image Retrieval

We propose a new efficient indexing scheme, called the HG-tree, to support content-based retrieval in image databases. Image content is represented by a point in a multidimensional feature space. The types of queries considered are the range query and the nearest-neighbor query, both in a multidimensional space. Our goals are twofold: increasing the storage utilization and decreasing the area covered by the directory regions of the index tree. The high storage utilization and the small directory area reduce the number of nodes that have to be touched during the query processing. The first goal is achieved by suppressing node splitting if possible, and when splitting is necessary, converting two nodes into three. This is done by proposing a good ordering on the directory nodes. The second goal is achieved by maintaining the area occupied by the directory region as small as possible. This is done by introducing the smallest interval that encloses all regions of the lower nodes. We note that there is a trade-off between the two design goals, but the HG-tree is so flexible that it can control the trade-off to some extent. We present the design of our indexing scheme and associated algorithms. In addition, we report the results of a series of tests, comparing the proposed index tree with the buddy-tree, which is one of the most successful point indexing schemes for a multidimensional space. The results show the superiority of our method.     

基于PCA和CHMM的音频自动分类*

针对DHMM分类器对音频特征进行向量量化引起的误差及特征维数过多导致计算复杂度过大的问题,提出了一种新的基于PCA和CHMM的音频自动分类方法。它先将音频特征组成一个高维向量,然后使用PCA对这些高维向量进行降维,再使用CHMM分类器对降维后的特征进行分类。实验证明了PCA和CHMM音频分类的有效性。