Graph-based representation for similarity retrieval of symbolic images

Image retrieval from an image database by the image objects and their spatial relationships has emerged as an important research subject in these decades. To retrieve images similar to a given query image, retrieval methods must assess the similarity degree between a database image and the query image by the extracted features with acceptable efficiency and effectiveness. This paper proposes a graph-based model SRG (spatial relation graph) to represent the semantic information of the contained objects and their spatial relationships in an image with no file annotation. In an SRG graph, the image objects are symbolized by the predefined class names as vertices and the spatial relations between object pairs are represented as arcs. The proposed model assesses the similarity degree between two images by calculating the maximum common subgraph of two corresponding SRG’s through intersection, which has quadratic time complexity owing to the characteristics of SRG. Its efficiency remains quadratic regardless of the duplication rate of the object symbols. The extended model SRG_T is also proposed, with the same time complexity, for the applications that need to consider the topological relations among objects. A synthetic symbolic image database and an existing image dataset are used in the conducted experiments to verify the performance of the proposed models. The experimental results show that the proposed models have compatible retrieval quality with remarkable efficiency improvements compared with three well-known methods LCS_Clique, SIM_R, and 2D Be-string, where LCS_Clique utilizes the number of objects in the maximum common subimage as its similarity function, SIM_R uses accumulation-based similarity function of similar object pairs, and 2D Be-string calculates the similarity of 2D patterns by the linear combination of two 1D similarities.     

Reasoning about pictures and similarity retrieval for image information systems based on SK-set knowledge representation

Spatial reasoning and similarity retrieval are two important functions of any image information system. Good spatial knowledge representation for images is necessary to adequately support these two functions. In this paper, we propose a new spatial knowledge representation, called the SK-set based on morphological skeleton theories. Spatial reasoning algorithms which achieve more accurate results by directly analysing skeletons are described. SK-set facilitates browsing and progressive visualization. We also define four new types of similarity measures and propose a similarity retrieval algorithm for performing image retrieval. Moreover, using SK-set as a spatial knowledge representation will reduce the storage space required by an image database significantly.     

<Emphasis Type="Italic">I-Quest</Emphasis>: an <Emphasis Type="Italic">i</Emphasis>ntelligent <Emphasis Type="Italic">que</Emphasis>ry <Emphasis Type="Italic">st</Emphasis>ructuring based on user browsing feedback for semantic retrieval of video data

In spite of significant improvements in video data retrieval, a system has not yet been developed that can adequately respond to a user’s query. Typically, the user has to refine the query many times and view query results until eventually the expected videos are retrieved from the database. The complexity of video data and questionable query structuring by the user aggravates the retrieval process. Most previous research in this area has focused on retrieval based on low-level features. Managing imprecise queries using semantic (high-level) content is no easier than queries based on low-level features due to the absence of a proper continuous distance function. We provide a method to help users search for clips and videos of interest in video databases. The video clips are classified as interesting and uninteresting based on user browsing. The attribute values of clips are classified by commonality, presence, and frequency within each of the two groups to be used in computing the relevance of each clip to the user’s query. In this paper, we provide an intelligent query structuring system, called I-Quest, to rank clips based on user browsing feedback, where a template generation from the set of interesting and uninteresting sets is impossible or yields poor results.

面向信息检索的藏文文本索引策略研究

互联网文本数量持续爆炸式增长,用户通过互联网查找信息变得更加困难,响应时间得不到满足。针对藏文本身的语言学特点,探讨一种面向信息搜索的藏文文本索引建立策略,建立一种高效的藏文文本索引,以提高藏文信息检索速度。     

Spatial inference and similarity retrieval of an intelligent image database system based on object's spanning representation

In this paper, we presented a novel image representation method to capture the information about spatial relationships between objects in a picture. Our method is more powerful than all other previous methods in terms of accuracy, flexibility, and capability of discriminating pictures. In addition, our method also provides different degrees of granularity for reasoning about directional relations in both 8- and 16-direction reference frames. In similarity retrieval, our system provides twelve types of similarity measures to support flexible matching between the query picture and the database pictures. By exercising a database containing 3600 pictures, we successfully demonstrated the effectiveness of our image retrieval system. Experiment result showed that 97.8% precision rate can be achieved while maintaining 62.5% recall rate; and 97.9% recall rate can be achieved while maintaining 51.7% precision rate. On an average, 86.1% precision rate and 81.2% recall rate can be achieved simultaneously if the threshold is set to 0.5 or 0.6. This performance is considered to be very good as an information retrieval system.     

Synchronization-Oriented Placement and Retrieval Strategies for Delay-Sensitive Media Streams

Multimedia data include text,image,audio and video,etc.Recent developments and advances in the areas of mass storage technology and high speed networks make it feasible for multimedia computing systems to offer services such as multimedia e-mial,teleconferencing and various vivid games.The storage and retrieval of multimedia data are two of the most important technologies in the futre multimedia systems.This paper analyzes the synchronization requirements of the delay-sensitive media streams,classifies the synchronization hierarchically and proposes several effective strategies for the intra-media and inter-media data placement problems.     

Trademark image retrieval using synthetic features for describing global shape and interior structure

A trademark image retrieval (TIR) system is proposed in this work to deal with the vast number of trademark images in the trademark registration system. The proposed approach commences with the extraction of edges using the Canny edge detector, performs a shape normalisation procedure, and then extracts the global and local features. The global features capture the gross essence of the shapes while the local features describe the interior details of the trademarks. A two-component feature matching strategy is used to measure the similarity between the query and database images. The performance of the proposed algorithm is compared against four other algorithms.     

Loss and gain functions for CBR retrieval

The method described in this article evaluates case similarity in the retrieval stage of case-based reasoning (CBR). It thus plays a key role in deciding which case to select, and therefore, in deciding which solution will be eventually applied. In CBR, there are many retrieval techniques. One feature shared by most is that case retrieval is based on attribute similarity and importance. However, there are other crucial factors that should be considered, such as the possible consequences of a given solution, in other words its potential loss and gain. As their name clearly implies, these concepts are defined as functions measuring loss and gain when a given retrieval case solution is applied. Moreover, these functions help the user to choose the best solution so that when a mistake is made the resulting loss is minimal. In this way, the highest benefit is always obtained.     

Inference and retrieval of soccer event

As to the soccer video, the event is defined as the medium-level spatiotemporal entity interesting to users, having certain context cues corresponding to the specific domain knowledge model. As a medium-level entity, the inference of soccer event is based on the fusion of context cues and domain knowledge model. The shooting event is chosen as research target and the event analysis method is expected to be reusable for other soccer events. According to the analysis of shooting event, the following seven kinds of context cues are extracted, respectively including one kind of caption detection, two kinds of face detection, one kind of audience detection, one kind of goal detection, and two kinds of motion estimation. In the inference of soccer event Bayesian network is used to perform the fusion of context cues. In the experiments the event retrieval is performed based on the video data of World Cup 2002, and the results show that the key to event retrieval is the extraction of context cues related with the user-defined event closely.     

Structural feature indexing for retrieval of partially visible shapes

Efficient and robust information retrieval from large image databases is an essential functionality for the reuse, manipulation, and editing of multimedia documents. Structural feature indexing is a potential approach to efficient shape retrieval from large image databases, but the indexing is sensitive to noise, scales of observation, and local shape deformations. It has now been confirmed that efficiency of classification and robustness against noise and local shape transformations can be improved by the feature indexing approach incorporating shape feature generation techniques (Nishida, Comput. Vision Image Understanding 73 (1) (1999) 121-136). In this paper, based on this approach, an efficient, robust method is presented for retrieval of model shapes that have parts similar to the query shape presented to the image database. The effectiveness is confirmed by experimental trials with a large database of boundary contours obtained from real images, and is validated by systematically designed experiments with a large number of synthetic data.     

Spatial reasoning and similarity retrieval for image database systems based on RS-strings

In this paper, we propose a rotation-invariant spatial knowledge representation called RS-string. Then we present the string generation algorithm to automatically generate RS-strings for segmented pictures. We also propose the spatial reasoning and similarity retrieval algorithms based on RS-strings. The similarity retrieval algorithm is much more flexible than all previous 2D string representations because our approach can consider every possible view of a query picture. Thus the system does not require the user to provide a query picture which must have the same orientation as that of a database picture. Finally, we provide several examples to demonstrate the capabilities of spatial reasoning and similarity retrieval based on the RS-string representation.     

Shot retrieval based on fuzzy evolutionary aiNet and hybrid features

As the multimedia data increasing exponentially, how to get the video data we need efficiently become so important and urgent. In this paper, a novel method for shot retrieval is proposed, which is based on fuzzy evolutionary aiNet and hybrid features. To begin with, the fuzzy evolutionary aiNet algorithm proposed in this paper is utilized to extract key-frames in a video sequence. Meanwhile, to represent a key-frame, hybrid features of color feature, texture feature and spatial structure feature are extracted. Then, the features of key-frames in the same shot are taken as an ensemble and mapped to high dimension space by non-linear mapping, and the result obeys Gaussian distribution. Finally, shot similarity is measured by the probabilistic distance between distributions of the key-frame feature ensembles for two shots, and similar shots are retrieved effectively by using this method. Experimental results show the validity of this proposed method.     

Similarity retrieval of iconic image database

The perception of spatial relationships among objects in a picture is one of the important selection criteria to discriminate and retrieve the images in an iconic image database system. The data structure called 2D string, proposed by Chang et al., is adopted to represent symbolic pictures. The 2D string preserves the objects' spatial knowledge embedded in images. Since spatial relationship is a fuzzy concept, the capability of similarity retrieval for the retrieval by subpicture is essential. In this paper, similarity measure based on 2D string longest common subsequence is defined. The algorithm for similarity retrieval is also proposed. Similarity retrieval provides the iconic image database with the distinguishing function different from a conventional database.     

基于文本聚类与分布式Lucene的知识检索

针对传统集中式索引处理大规模数据的性能和效率问题,提出了一种基于文本聚类的检索算法。利用文本聚类算法改进现有的索引划分方案,根据查询与聚类结果的距离计算判断查询意图,缩减查询范围。实验结果表明,所提方案能够有效地缓解大规模数据建索引和检索的压力,大幅提高分布式检索性能,同时保持着较高的准确率和查全率。     

Techniques used and open challenges to the analysis,indexing and retrieval of digital video

Video in digital format is now commonplace and widespread in both professional use, and in domestic consumer products from camcorders to mobile phones. Video content is growing in volume and while we can capture, compress, store, transmit and display video with great facility, editing videos and manipulating them based on their content is still a non-trivial activity. In this paper, we give a brief review of the state of the art of video analysis, indexing and retrieval and we point to research directions which we think are promising and could make searching and browsing of video archives based on video content, as easy as searching and browsing (text) web pages. We conclude the paper with a list of grand challenges for researchers working in the area.     

基于XML和ANN的Web文本智能检索研究

传统的网络信息检索技术如搜索引擎存在一些不足,一方面它只是将信息搜寻出来,不能发现隐藏在数据背后的知识;另一方面其采集软件在采集数据时缺乏人工干预,智能性不强,导致信息利用率不高.针对传统的Web搜索引擎存在的上述问题,结合Web文本挖掘、XML、BP神经网络在数据处理方面的长处,提出了一个具有一定智能的Web文本信息检索模型,以使其具有较高的信息利用率.     

A database system of mechanical components based on geometric and topological similarity. Part II: indexing, retrieval, matching, and similarity assessment

This paper presents an approach for retrieving and matching similar designs in a database of mechanical components. The retrieval and matching process is based on the geometric and topological similarity between mechanical components. The process constitutes five steps: (i) transforming the component from the CAD system in STEP format, (ii) building an attributed graph for it, (iii) abstracting the graph into some geometric entities, (iv) retrieving a set of similar graphs based on the abstracted data, and (v) matching the graph of the new design with each graph on the set of similar graphs. This paper addresses the last three steps. Retrieving and matching mechanical parts based on their shape has many applications such as cost estimation and process planning. Matching similar parts and calculating a similarity index for them has applications in manufacturing evaluation, design by case-based reasoning, robotics, and computer integrated manufacturing. Having a database system of mechanical components based on part shape serves in all of these applications.