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Effective and efficient retrieval of similar shapes from large image databases is still a challenging problem in spite of the high relevance that shape information can have in describing image contents. In this paper, we propose a novel Fourier-based approach, called WARP, for matching and retrieving similar shapes. The unique characteristics of WARP are(More)
In this paper we present WINDSURF (Wavelet-Based Indexing of Images Using Region Fragmentation), a new approach to content-based image retrieval. The method uses the wavelet transform to extract color and texture features from an image and applies a clustering technique to partition the image into a set of " homogeneous " regions. Similarity between images(More)
Skyline queries compute the set of Pareto-optimal tuples in a relation, ie those tuples that are not <i>dominated</i> by any other tuple in the same relation. Although several algorithms have been proposed for efficiently evaluating skyline queries, they either require to extend the relational server with specialized access methods (which is not always(More)
In recent years, several methods have been proposed for implementing interactive similarity queries on multimedia databases. Common to all these methods is the idea to exploit user feedback in order to progressively adjust the query parameters and to eventually converge to an " optimal " parameter setting. However, all these methods also share the feature(More)
Managing photos by using low-level visual features is a powerful , yet imprecise, organization paradigm. The same is true if only keywords (or tags) are used. In this paper we present a new browsing and search system, named Scenique, that allows the user to manage her photo collections by using both visual features and tags, all homogeneously organized into(More)
Skyline queries compute the set of Pareto-optimal tuples in a relation, that is, those tuples that are not <i>dominated</i> by any other tuple in the same relation. Although several algorithms have been proposed for efficiently evaluating skyline queries, they either necessitate the relation to have been indexed or have to perform the dominance tests on(More)
Region-based image retrieval systems aim to improve the effectiveness of content-based search by decomposing each image into a set of " homogeneous " regions. Thus, similarity between images is assessed by computing similarity between pairs of regions and then combining the results at the image level. In this paper we propose the first prov-ably sound(More)
One of the most important operations involving Data Mining patterns is computing their similarity. In this paper we present a general framework for comparing both simple and complex patterns, i.e., patterns built up from other patterns. Major features of our framework include the notion of structure and measure similarity, the possibility of managing(More)
Searching in a large data set those strings that are more similar , according to the edit distance, to a given one is a time-consuming process. In this paper we investigate the performance of metric trees, namely the M-tree, when they are extended using a cheap approximate distance function as a filter to quickly discard irrelevant strings. Using the bag(More)