【作者】 蒋仁波；

【导师】 卢健；

【作者基本信息】 武汉大学 ， 地理信息系统， 2004， 硕士

【摘要】 在数据库系统和计算机视觉两大研究领域的共同推动下，图像检索技术已逐渐成为一个非常活跃的研究领域。基于内容的图像检索不同于传统的基于文本的图像检索，它实际上是一种模糊查询技术，通过对图像数提取一定的特征，找出在特征空间中与查询要求最接近的图像。这就涉及两个方面问题，一、如何提取特征，二、特征向量间距离如何测量，也就是特征如何匹配的问题。 另外，无论采用何种特征，无论使用何种距离测度，最终决定两幅图像是否相似还取决于实际用户。不同的用户对图像的相似性的判断也存在不同的标准。因此，提出将相关反馈技术应用到图像检索中来。相关反馈的目标是从用户与查询系统的实际交互过程中进行学习，发现并捕捉用户的实际查询意图，并以此修正系统的查询策略，从而得到与用户实际需求尽可能相吻合的查询结果。由于相关反馈可以实时地修改系统的查询策略，从而为图像检索系统增加了自适应功能。 本文主要针对基于内容的图像检索所涉及的以上三方面技术进行深入的探讨和研究，并选择合适的算法，设计开发了基于内容的图像检索数据库实验系统。 本文第二章是全文的核心部分，分别讨论了颜色特征、纹理特征和形状特征的提取和表达。主要研究内容和成果有： 首先，详细归纳和总结了颜色、纹理及形状特征的提取和表达的诸多方法。 其次，对部分特征的有效性进行了实验，比如，对于颜色特征，就对比了颜色直方图在不同颜色空间中的有效性，并与多分辨率分块主色索引进行了对比，最后给出实验示例。 再次，以实验为基础，抽取、结合有效特征，并在效率和精确性方面加以了改进。例如，就形状特征，本文抽取了离心率、紧致度、形状不变距和傅立叶描述符组成特征向量，进行实验并取得较好的效果。 本文第三章主要讨论特征匹配的方法，包括：欧式距离、马氏距离、直方图相交等，除此之外还在第二小节给出了本文所用到的一些特征匹配方法。 第四章是本文具有创新的部分，首先，在众多相关反馈理论中选取了最为简单而有效的方法，并以此原理为基础，设计了行之有效且简单友好的查询界面。 第五章主要讨论了实验系统的设计和实施，并给出系统运行效果示例。第六章是全文的总结，主要通过结论性的语言对作者所进行的工作进行了客观的评价并对此方向的发展动态进行了展望。更多还原

【Abstract】 With the development of database system and computer vision, image retrieval technique becomes a very active research field gradually. The content-based image retrieval (CBIR) is different from the traditional text-based image retrieval. It is a fuzzy inquiry technology in fact. Through extracting the characteristic of the image, we may find out the image that is most close to the enquiring requirement in the characteristic space. The issue involves two aspects: the extraction of characteristics, and the measurement of the distance between two characteristics vectors, i.e. the problem of characteristic match.In addition, it finally depends on the actual users to determine whether the two images are similar or not despise different adoption of characteristics and estimation of distance. Different users have different standards to the similar judgment of the image too. Hence, relevant feedback technology is advanced and applied to the image retrieval. The goal of it is to study from mutual course between the users and the inquiry system to find and catch their actual inquiry intentions, and revise the systematic inquiry tactics, thus, get the inquiry results as identical as possible to the users’ actual demands. Because it could revise the systematic inquiry tactics real-timely, adaptive function has been added to the image retrieval system.The paper carries on the deep discussion and studies on the above three respects of the technology involved in CBIR system, and chosen suitable algorithm, designed and developed a CBIR experimental system. Chapter two of this paper is a key part of the full text, and discussed the extraction and expression of the color, texture, and shape characteristic separately. Main research contents and achievement have:First of all, a great deal of methods of extraction and expression about the color, texture and shape characteristic are summed up and summarized in detail. Secondly, we experiment the validity of some characteristics, for example, to the color characteristic, we compare with the validity of color histogram in different color space, and go on the contrast to Pieces of Multi-resolution main color index, and provide experiment demonstration finally.Based on the experiment, we collecte and combine the effective characteristic, and improve the algorithms in efficiency and accuracy. For example of shape characteristic, we chose eccentricity, compactness, shape invariant quadrature, andFourier descriptors to combine characteristic vector, and carry on the experiment and make better result.The third chapter mainly discusses the method of characteristic match, include: L1 and L2 distance, Mahalanobis distance, quadratic form distance and histogram intersection. In addition, characteristic match methods used in CBIR experimental system are presented.The innovation of the paper lies in chapter four. At first, we chose the simplest and valid method in numerous relevant feedback theories, and according to it, we design a simple and friendly inquiry interface. Chapter five mainly discussed the design and implementation of the experimental system, and provid the demonstration of systematic operation result. Chapter six is a summary of the full text, carry on objective appraisal to the author’s work with conclusive language, and expect the development trends in this field.更多还原