{"title":"A case-study of scoring schemes for the PvS-index","authors":"Herwig Lejsek","doi":"10.1145/1160939.1160953","DOIUrl":"https://doi.org/10.1145/1160939.1160953","url":null,"abstract":"Recently we have proposed a new indexing method for high-dimensional data, the PvS-index. It provides fast query processing in constant time and is well suited for doing similarity search in Image Retrieval Systems using local descriptors. It is based on projecting data points onto random lines and uses this information to segment them into appropriately sized buckets, which can be read in just one I/O operation. After this preprocessing step the search queries just three buckets per query descriptor and uses a recent rank aggregation method, OMEDRANK, in order to provide good approximate results for the nearest neighbour problem.We have recently shown that PvS-indexing works well for large collections of real image data. In that work, however, we used a simple scoring scheme and collected few nearest neighbours for each query descriptor. In this study we examine how much the actual number of nearest neighbours, gathered for each local descriptor, influences the final query result, when searching a PvS-index. Based on the results we propose two new alternative scoring schemes, which improve the retrieval quality and stabilise the results, making the search less affected by the actual number of nearest neighbours accumulated.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123691593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Data embedding techniques and applications","authors":"Li Yang","doi":"10.1145/1160939.1160948","DOIUrl":"https://doi.org/10.1145/1160939.1160948","url":null,"abstract":"As an effective way for dimensionality reduction, data embedding has direct applications in data mining, data indexing and searching, information retrieval, and multimedia data processing. As two representative techniques for data embedding, both Isomap and LLE require the construction of neighborhood graphs on which every point is connected to its neighbors. This paper reviews several techniques that have been developed to construct connected neighborhood graphs. These methods have made Isomap and LLE applicable to a wide range of data including under-sampled data and non-uniformly distributed data. Application-related issues of data embedding techniques are also discussed.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128142837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the impact of outliers on high-dimensional data analysis methods for face recognition","authors":"Sid-Ahmed Berrani, Christophe Garcia","doi":"10.1145/1160939.1160952","DOIUrl":"https://doi.org/10.1145/1160939.1160952","url":null,"abstract":"In this paper, the impact of outliers on the performance of high-dimensional data analysis methods is studied in the context of face recognition. Most of the existing face recognition methods are based on PCA-like methods: Faces are projected into a lower dimensional space in which similarity between faces is more easily evaluated. These methods are, however, very sensitive to the quality of face images used in the training and the recognition phases. Their performance significantly degrades when faces are not well centered or taken under variable illumination conditions. In this paper, we study this phenomenon for two face recognition methods (PCA and LDA2D) and we propose a filtering process that allows an automatic isolation of noisy faces which are responsible for the performance degradation. This process is performed during the training phase as well as the recognition phase. It is based-on the recently proposed robust high-dimensional data analysis method RobPCA. Experiments show that this filtering process improves the recognition rate by 10 to 20%.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"25 19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128541394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Optimizing progressive query-by-example over pre-clustered large image databases","authors":"A. Choupo, Laure Berti-Équille, A. Morin","doi":"10.1145/1160939.1160946","DOIUrl":"https://doi.org/10.1145/1160939.1160946","url":null,"abstract":"The typical mode for querying in an image content-based information system is query-by-example, which allows the user to provide an image as a query and to search for similar images (i.e., the nearest neighbors) based on one or a combination of low-level multidimensional features of the query example. Off-lime, this requires the time-consuming pre-computing of the whole set of visual descriptors over the image database. On-line, one major drawback is that multidimensional sequential NN-search is usually exhaustive over the whole image set face to the user who has a very limited patience. In this paper, we propose a technique for improving the performance of image query-by-example execution strategies over multiple visual features. This includes first, the pre-clustering of the large image database and then, the scheduling of the processing of the feature clusters before providing progressively the query results (i.e., intermediate results are sent continuously before the end of the exhaustive scan over the whole database). A cluster eligibility criterion and two filtering rules are proposed to select the most relevant clusters to a query-by-example. Experiments over more than 110 000 images and five MPEG-7 global features show that our approach significantly reduces the query time in two experimental cases: the query time is divided by 4.8 for 100 clusters per descriptor type and by 7 for 200 clusters per descriptor type compared to a \"blind\" sequential NN-search with keeping the same final query result. This constitutes a promising perspective for optimizing image query-by-example execution.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128794120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A fast shot matching strategy for detecting duplicate sequences in a television stream","authors":"Xavier Naturel, P. Gros","doi":"10.1145/1160939.1160947","DOIUrl":"https://doi.org/10.1145/1160939.1160947","url":null,"abstract":"This article presents a method for detecting duplicate sequences in a continuous television stream. This is of interest to many applications, including commercials monitoring and video indexing. Repetitions can also be used as a way of structuring television streams by detecting inter-program breaks as a set of duplicate sequences. In this context, we present a shot-based method for detecting repeated sequences efficiently. Experiments show that this fast shot matching strategy allows us to retrieve duplicated shots between a 1 hour long query and a 24 hours database in only 10 ms.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"407 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117098315","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Joint exploitation of multiple media from multimedia to databases","authors":"P. Gros","doi":"10.1145/1160939.1160943","DOIUrl":"https://doi.org/10.1145/1160939.1160943","url":null,"abstract":"Multimedia content analysis offers many exciting research opportunities and is a necessary step towards automatic understanding of the content of digital documents. Digital documents are typically composite. Processing in parallel and integrating low-level information computed over each of the media that compose a multimedia document can yield knowledge that stand-alone and isolated analysis could not discover.Joint processing of multiple media is very challenging, even at the lowest analysis levels. Coping with imperfect synchronization of pieces of information, mixing extremely different kinds of information (numerical or symbolic descriptions, values describing intervals or instants, probabilities and distances, HMM and Gaussians, ...), and reconciling contradictory outputs are some of the obstacles which make processing of multimedia documents much more difficult than it seems at first glance.This talk will first show what may be gained from jointly analyzing multimedia documents. It will then briefly overview the typical information that can be extracted from major media (video, sound, images and text) before focusing on the problems that arise when trying to use all this information together. We hope to convince researchers to start trying to solve these problems, since they directly hamper the acquisition of higher-level knowledge from multimedia documents.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130050766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Using pivots to index for support vector machine queries","authors":"Arun Qamra, E. Chang","doi":"10.1145/1160939.1160954","DOIUrl":"https://doi.org/10.1145/1160939.1160954","url":null,"abstract":"In many data-mining applications, Support Vector Machines are used to learn query concepts, and then the learned SVM is used to find the corresponding best matches in a given dataset. When the dataset is large, naively scanning the entire dataset to find the instances with the highest classification scores is not practical. An indexing strategy is thus desirable for scalability. In contrast to queries in traditional similarity search scenarios which are in the form of an input space point, SVM queries are hyperplanes in a (kernel function induced) feature space, and the best matches are instances farthest from the hyperplane. Also, the kernel parameters used, and hence the feature space used, may vary with the query. These issues make the problem challenging. In this work, we propose an indexing strategy that uses pivots (selected using PCA or KPCA) to prune irrelevant instances from the dataset, and zoom in on a smaller candidate set, to efficiently answer SVM queries.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116575179","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Similarity search in high-dimensional datasets","authors":"R. Ramakrishnan, J. Goldstein, U. Shaft","doi":"10.1145/1160939.1160941","DOIUrl":"https://doi.org/10.1145/1160939.1160941","url":null,"abstract":"The problem of finding \"similar\" multimedia objects is a central one, and a popular approach is to represent objects as vectors in a high-dimensional space, and to build a spatial index over a collection of such vectors in order to retrieve the \"nearest neighbors\" of a query object. There are some fundamental assumptions involved here. First, that the user's notion of similarity can be captured by distance in the space that the vectors are embedded, and second, that nearest neighbors can be efficiently retrieved. In this talk, we discuss these assumptions, based on our experience with the PiQ image database project, carried out at the University of Wisconsin-Madison, and some subsequent work.We will first present a brief overview of the PiQ system and its goal of identifying the DBMS infrastructure required to support image databases, and discuss the role of similarity and nearest-neighbor queries in content-based querying. Next, we consider when the notion of \"nearest neighbor\" is well-defined in high-dimensional spaces, and when efficient indexing is feasible. The goal is not to suggest that indexing high-dimensional data is impossible, although our results here are mainly negative. Rather, we seek to identify the conditions under which effective indexing and retrieval techniques are feasible, and to identify the key difficulties that must be overcome. Finally, we present some indexing techniques to retrieve nearest neighbors under appropriate conditions, highlighting the role played by redundancy and approximation.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115308549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
John R. Smith, D. Doermann, Amarnath Gupta, J. Goldstein, U. Shaft, N. Ratha
{"title":"Multimedia applications: beyond similarity searches","authors":"John R. Smith, D. Doermann, Amarnath Gupta, J. Goldstein, U. Shaft, N. Ratha","doi":"10.1145/1160939.1160957","DOIUrl":"https://doi.org/10.1145/1160939.1160957","url":null,"abstract":"Relational database systems solve many of the traditional problems for processing of structured data. However, unstructured data in the form of images, video, audio and multimedia is growing at a tremendous rate and introduces new requirements that are not met by today's database engines. One well known example is content-based retrieval that involves similarity searching and indexing in high-dimensional feature spaces. In addition there has been much recent focus on applying machine learning techniques involving semantics modeling, spatio-temporal indexing, multi-modal (audio-, visual-, textual-) integration and relevance feedback searching.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127037106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"EXTENT: fusing context, content, and semantic ontology for photo annotation","authors":"E. Chang","doi":"10.1145/1160939.1160945","DOIUrl":"https://doi.org/10.1145/1160939.1160945","url":null,"abstract":"This architecture paper presents EXTENT, a probabilistic framework that uses influence diagrams to fuse metadata of multiple modalities for photo annotation. EXTENT fuses contextual information (location, time, and camera parameters), photo content (perceptual features), and semantic ontology in a synergistic way. It uses causal strengths to encode causalities between variables, and between variables and semantic labels. Through a landmark-recognition case study, we show that EXTENT can provide high-quality annotation, substantially better than any traditional unimodal methods.","PeriodicalId":346313,"journal":{"name":"Computer Vision meets Databases","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2005-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127446480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}