首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
2.
We present a new text-to-image re-ranking approach for improving the relevancy rate in searches. In particular, we focus on the fundamental semantic gap that exists between the low-level visual features of the image and high-level textual queries by dynamically maintaining a connected hierarchy in the form of a concept database. For each textual query, we take the results from popular search engines as an initial retrieval, followed by a semantic analysis to map the textual query to higher level concepts. In order to do this, we design a two-layer scoring system which can identify the relationship between the query and the concepts automatically. We then calculate the image feature vectors and compare them with the classifier for each related concept. An image is relevant only when it is related to the query both semantically and content-wise. The second feature of this work is that we loosen the requirement for query accuracy from the user, which makes it possible to perform well on users’ queries containing less relevant information. Thirdly, the concept database can be dynamically maintained to satisfy the variations in user queries, which eliminates the need for human labor in building a sophisticated initial concept database. We designed our experiment using complex queries (based on five scenarios) to demonstrate how our retrieval results are a significant improvement over those obtained from current state-of-the-art image search engines.  相似文献   

3.
提出了基于神经网络的交互式图像检索方法,系统根据用户对检索结果的评价,动态构造神经网络,描述图像之间的相似性;图像间的这种相似性以及本次检索结果可以作为以后检索的历史信息保存在神经网络中,从而提高下一次检索的效率。实验表明,该方法嵌入到典型的图像检索系统中,改善了图像检索性能。  相似文献   

4.
We introduce a semantic data model to capture the hierarchical, spatial, temporal, and evolutionary semantics of images in pictorial databases. This model mimics the user's conceptual view of the image content, providing the framework and guidelines for preprocessing to extract image features. Based on the model constructs, a spatial evolutionary query language (SEQL), which provides direct image object manipulation capabilities, is presented. With semantic information captured in the model, spatial evolutionary queries are answered efficiently. Using an object-oriented platform, a prototype medical-image management system was implemented at UCLA to demonstrate the feasibility of the proposed approach.  相似文献   

5.
6.
目前多数基于内容的图像检索研究是在如何理解图像的内容,挖掘图像内容的特征,并组织这些特征用于图像检索上。检索得到的结果往往丢弃不顾,不能用于未来相似语义图像的检索。提出了一种新颖的基于语义保存的图像检索方案:将检索得到的多个相似图像组成相似图像网络,并运用复杂性网络的子网络分割方法,划分出语义子网络,找出语义概念并保存;检索未来相似内容的图像只需匹配保存的图像语义概念。实验表明,检索后得到的图像网络具有小世界网络的特征;保存的图像语义能准确地匹配相似语义内容图像,并能极大地加快检索相似语义图像。  相似文献   

7.
The common problem in content based image retrieval (CBIR) is selection of features. Image characterization with lesser number of features involving lower computational cost is always desirable. Edge is a strong feature for characterizing an image. This paper presents a robust technique for extracting edge map of an image which is followed by computation of global feature (like fuzzy compactness) using gray level as well as shape information of the edge map. Unlike other existing techniques it does not require pre segmentation for the computation of features. This algorithm is also computationally attractive as it computes different features with limited number of selected pixels.  相似文献   

8.
张辉 《计算机工程与设计》2011,32(12):4291-4294
为提高在海量数据中的信息检索效率,分析了元数据目录服务技术的现状及其不足,通过引入语义关联技术,将语义关联的信息检索技术与网格信息服务技术有效结合,提出了一种改进的能有效提高检索效率的检索框架,并结合实例进行了描述.实验结果表明,该优化的语义关联查询方法是有效、可行的,能有效提高海量数据中信息检索的查准率和查全率.  相似文献   

9.
Typical content-based image retrieval solutions usually cannot achieve satisfactory performance due to the semantic gap challenge. With the popularity of social media applications, large amounts of social images associated with user tagging information are available, which can be leveraged to boost image retrieval. In this paper, we propose a sparse semantic metric learning (SSML) algorithm by discovering knowledge from these social media resources, and apply the learned metric to search relevant images for users. Different from the traditional metric learning approaches that use similar or dissimilar constraints over a homogeneous visual space, the proposed method exploits heterogeneous information from two views of images and formulates the learning problem with the following principles. The semantic structure in the text space is expected to be preserved for the transformed space. To prevent overfitting the noisy, incomplete, or subjective tagging information of images, we expect that the mapping space by the learned metric does not deviate from the original visual space. In addition, the metric is straightforward constrained to be row-wise sparse with the ?2,1-norm to suppress certain noisy or redundant visual feature dimensions. We present an iterative algorithm with proved convergence to solve the optimization problem. With the learned metric for image retrieval, we conduct extensive experiments on a real-world dataset and validate the effectiveness of our approach compared with other related work.  相似文献   

10.
当前主流的Web图像检索方法仅考虑了视觉特征,没有充分利用Web图像附带的文本信息,并忽略了相关文本中涉及的有价值的语义,从而导致其图像表达能力不强。针对这一问题,提出了一种新的无监督图像哈希方法——基于语义迁移的深度图像哈希(semantic transfer deep visual hashing,STDVH)。该方法首先利用谱聚类挖掘训练文本的语义信息;然后构建深度卷积神经网络将文本语义信息迁移到图像哈希码的学习中;最后在统一框架中训练得到图像的哈希码和哈希函数,在低维汉明空间中完成对大规模Web图像数据的有效检索。通过在Wiki和MIR Flickr这两个公开的Web图像集上进行实验,证明了该方法相比其他先进的哈希算法的优越性。  相似文献   

11.
针对大规模专利图像特征库的特点,使用边缘轮廓距离与分块特征相结合的方法提取低层视觉特征,结合基于K均值聚类的分类索引方法,兼顾语义相似和视觉特征相似,对专利图像库数据构建索引结构,实现了先分类后检索的功能。实验结果表明,方法不仅提高了检索速度,而且提高了检索的语义敏感度。  相似文献   

12.
We propose a specific content-based image retrieval (CBIR) system for hyperspectral images exploiting its rich spectral information. The CBIR image features are the endmember signatures obtained from the image data by endmember induction algorithms (EIAs). Endmembers correspond to the elementary materials in the scene, so that the pixel spectra can be decomposed into a linear combination of endmember signatures. EIA search for points in the high dimensional space of pixel spectra defining a convex polytope, often a simplex, covering the image data. This paper introduces a dissimilarity measure between hyperspectral images computed over the image induced endmembers, proving that it complies with the axioms of a distance. We provide a comparative discussion of dissimilarity functions, and quantitative evaluation of their relative performances on a large collection of synthetic hyperspectral images, and on a dataset extracted from a real hyperspectral image. Alternative dissimilarity functions considered are the Hausdorff distance and robust variations of it. We assess the CBIR performance sensitivity to changes in the distance between endmembers, the EIA employed, and some other conditions. The proposed hyperspectral image distance improves over the alternative dissimilarities in all quantitative performance measures. The visual results of the CBIR on the real image data demonstrate its usefulness for practical applications.  相似文献   

13.
Content Based Image Retrieval (CBIR) systems use Relevance Feedback (RF) in order to improve the retrieval accuracy. Research focus has been shifted from designing sophisticated low-level feature extraction algorithms to reducing the “semantic gap” between the visual features and the richness of human semantics. In this paper, a novel system is proposed to enhance the gain of long-term relevance feedback. In the proposed system, the general CBIR involves two steps—ABC based training and image retrieval. First, the images other than the query image are pre-processed using median filter and gray scale transformation for removal of noise and resizing. Secondly, the features such as Color, Texture and shape of the image are extracted using Gabor Filter, Gray Level Co-occurrence Matrix and Hu-Moment shape feature techniques and also extract the static features like mean and standard deviation. The extracted features are clustered using k-means algorithm and each cluster are trained using ANN based ABC technique. A method using artificial bee colony (ABC) based artificial neural network (ANN) to update the weights assigned to features by accumulating the knowledge obtained from the user over iterations. Eventually, the comparative analysis performed using the commonly used methods namely precision and recall were clearly shown that the proposed system is suitable for the better CBIR and it can reduce the semantic gap than the conventional systems.  相似文献   

14.
提出一种结合图像分块纹理特征和语义信息的医学胸片图像检索方法。同时,介绍了颜色特征提取方法中的颜色相关图算法。据此,实现了一个图像检索原型系统,依据所设计的评价实验,将不同实验的检索结果进行了比较和分析。实验证明,结合图像分块纹理特征和语义信息的检索方法具有较好的检索效果。  相似文献   

15.
Ou  Xinyu  Ling  Hefei  Liu  Si  Lei  Jie 《Multimedia Tools and Applications》2017,76(20):21281-21302
Multimedia Tools and Applications - Content-Based large-scale image retrieval has recently attracted considerable attention because of the explosive increase of online images. Inspired by recent...  相似文献   

16.
为了从海量的道路交通图像中检索出违反交通法规的图像,提出了一种特定目标自识别的语义图像检索方法。首先,通过交通领域专家建立交通领域本体及道路交通规则描述;然后,通过卷积神经网络(CNN)对交通图像的特征进行提取,并结合改进的支持向量机决策树(SVM-DT)算法对图像特征进行分类的策略,对交通图像中的特定目标及目标间空间位置关系进行自动识别,并映射成为相应的本体实例及其对象之间的关联关系(规则实例);最后,利用本体实例和规则实例,通过推理得到语义检索结果。实验结果表明,相比关键字和本体交通图像语义检索方法,所提方法具有更高的准确率、召回率和检索效率。  相似文献   

17.
The emergence of cloud datacenters enhances the capability of online data storage. Since massive data is stored in datacenters, it is necessary to effectively locate and access interest data in such a distributed system. However, traditional search techniques only allow users to search images over exact-match keywords through a centralized index. These techniques cannot satisfy the requirements of content based image retrieval (CBIR). In this paper, we propose a scalable image retrieval framework which can efficiently support content similarity search and semantic search in the distributed environment. Its key idea is to integrate image feature vectors into distributed hash tables (DHTs) by exploiting the property of locality sensitive hashing (LSH). Thus, images with similar content are most likely gathered into the same node without the knowledge of any global information. For searching semantically close images, the relevance feedback is adopted in our system to overcome the gap between low-level features and high-level features. We show that our approach yields high recall rate with good load balance and only requires a few number of hops.  相似文献   

18.
为了在图像语义标注领域能更好地反映标注之间的关系,通过对已标注图像的标注进行分析来建立标 注之间的关系,并在此基础上将叙词查询的概念引入到图像语义标注中并提出了基于叙词查询的图像语义标注 方法,把语义标注问题统一在叙词查询与图像的语义关系相结合在统一的框架下,最后通过在Corel图像数据库中的验证表明,所提出的方法是有效的并且标注率得到了明显的提高。  相似文献   

19.
We investigate the extraction of effective color features for a content-based image retrieval (CBIR) application in dermatology. Effectiveness is measured by the rate of correct retrieval of images from four color classes of skin lesions. We employ and compare two different methods to learn favorable feature representations for this special application: limited rank matrix learning vector quantization (LiRaM LVQ) and a Large Margin Nearest Neighbor (LMNN) approach. Both methods use labeled training data and provide a discriminant linear transformation of the original features, potentially to a lower dimensional space. The extracted color features are used to retrieve images from a database by a k-nearest neighbor search. We perform a comparison of retrieval rates achieved with extracted and original features for eight different standard color spaces. We achieved significant improvements in every examined color space. The increase of the mean correct retrieval rate lies between 10% and 27% in the range of k=1-25 retrieved images, and the correct retrieval rate lies between 84% and 64%. We present explicit combinations of RGB and CIE-Lab color features corresponding to healthy and lesion skin. LiRaM LVQ and the computationally more expensive LMNN give comparable results for large values of the method parameter κ of LMNN (κ≥25) while LiRaM LVQ outperforms LMNN for smaller values of κ. We conclude that feature extraction by LiRaM LVQ leads to considerable improvement in color-based retrieval of dermatologic images.  相似文献   

20.
裴焱栋  顾克江 《计算机应用》2020,40(7):1863-1872
多媒体信息的检索是信息复用的重要途径。三维模型检索作为三维建模过程中的关键技术之一,近年来随着三维建模的广泛运用而被深入研究。针对目前三维模型检索技术的进展,首先介绍了基于内容的检索技术,按照提取的特征将其分为四类:基于统计数据、基于几何外形、基于拓扑结构和基于视觉特征,分别介绍各类技术的主要成果和优缺点;然后介绍考虑语义信息,解决“语义鸿沟”现象的基于语义的检索方法,根据切入角度将其分为三类:相关性反馈、主动学习和本体技术,随后介绍了各类技术的相互关系与特点;最后总结和提出了三维模型检索的未来研究的发展方向。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号