Stefano Levialdi

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*Dipartimento di Informatica e Sistemistica, Università di Roma "La Sapienza", Via Salaria 113, 00198 Roma, Italy, e-mail: [catarci/batini] °Dipartimento di Informatica, Università di Bari, Via Orabona 4, 70125 Bari, Italy, e-mail: ^Dipartimento di Scienze dell'Informazione, Università di Roma "La Sapienza",(More)
The paper describes a new indexing methodology for image databases integrating color and spatial information for content-based image retrieval. This methodology, called Spatial-Chromatic Histogram (SCH), synthesizing in few values information about the location of pixels having the same color and their arrangement within the image, can be more satisfactory(More)
Digital annotation of multimedia documents adds information to a document (e.g. a web page) or parts of it (a multimedia object such as an image or a video stream contained in the document). Digital annotations can be kept private or shared among different users over the internet, allowing discussions and cooperative work. We study the possibility of(More)
Despite recent advances of electronic technologies in e-learning, a consolidated evaluation methodology for e-learning applications is not available. The evaluation of educational software must consider its usability and more in general its accessibility, as well as its didactic effectiveness. This work is a first step towards the definition of a(More)
The new challenge for designers and HCI researchers is to develop software tools for effective e-learning. Learner-Centered Design (LCD) provides guidelines to make new learning domains accessible in an educationally productive manner. A number of new issues have been raised because of the new "vehicle" for education. Effective e-learning systems should(More)
To appear in IEEE Transactions on Data and Knowledge Engineering, 1995-96 1Abstract We describe an approach for multiparadigmatic visual access to databases, which i s proposed to achieve seamless integration of different interaction paradigms. The user i s provided with an adaptive interface augmented by a user model, supporting different visual(More)
An image can be regarded as a fuzzy subset of a plane. A fuzzy entropy measuring the blur in an image is a functional which increases when the sharpness of its argument image decreases. We generalize and extend the relation "sharper than" between fuzzy sets in view of implementing the properties of a relation "sharper than" between images. We show that(More)
To efficiently solve the image retrieval problem in an image database, many techniques have been devised addressing the requirements of different applications. Present information management systems exploit these techniques to allow querying of pictorial documents archives. To do this, the first step is to extract relevant keys from the image content(More)
A parallel processing algorithm for shrinking binary patterns to obtain single isolated elements, one for each pattern, is presented. This procedure may be used for counting patterns on a matrix, and a hardware implementation of the algorithm using large scale integrated tecnology is envisioned. The principal features of this method are the very small(More)