645 research outputs found
Symmetrical Segmentation Based Image Coding
No full textAn image coding technique based on symmetry extraction and Binary Space Partitioning (BSP) tree representation for still pictures is presented. Axes of symmetry, detected through a principal axis of inertia approach and a coefficient of symmetry measure, are used to divide recursively an input image into a finite number of convex regions. This recursive partitioning results in the BSP tree representation of the image data. The iterative partition occurs whenever the current left/right node of the tree cannot be represented `symmetrically' by its counterpart, i.e., the right/left node. This splitting process may also end whenever the region associated with a given node has homogeneous characteristics or its size falls below a certain threshold. Given a BSP tree partition for a given input image, and the `seed' leaf nodes (i.e., those that cannot be generated by mirroring their counterparts), the remaining leaf nodes of the tree are reconstructed using a predictive scheme with respect to the `seed' leaf nodes
Identification of Successive Correlated Camera Shots Using Audio and Video Information
No full textEffective creation and utilization of large digital multimedia libraries involves the application of multimedia processing techniques to organize, condense and index media for intelligent searching and selective retrieval. The segmentation of video sequences into scenes and the characterization of each scene has been suggested as a technique for organizing video information. As human beings use both auditory and visual systems to perceive the semantics of audio-visual sources, the analysis of the associated audio signal is shown to serve as a support for organizing video information
Caterina Colombini, o della cugina sedotta. Una ‘ricostruzione’ della figura di Caterina attraverso i testi
No full textIn this essay the author demonstrates that it is possible to “reconstruct” the figure of Caterina Colombini (1340?-1387) – Giovanni Colombini’s cousin – through a group of texts: the hagiography of Caterina, the letters sent to her by Giovanni Colombini and, finally, Giovanni’s biography written by Feo Belcari. The author divides his text into four parts: the first part analyzes the content of Caterina’s hagiography; the second examines the linguistic form of the hagiographic text; in the third, the author analyzes the latent meaning of the window, a symbolic place where Giovanni and Caterina converse on divine topics; in the last part, to conclude, the teachings that Giovanni gives to Catherine and her spiritual daughters – the Gesuate – are analyzed
Indexing Audio-Visual Sequences by Joint Audio and Video Processing
No full textThe focus of this work is oriented to the creation of a content-based hierarchical organisation of audio-visual data (a description scheme) and to the creation of meta-data (descriptors) to associate with audio and/or visual signals. The generation of efficient indices to access audio-visual databases is strictly connected to the generation of content descriptors and to the hierarchical representation of audio-visual material. Once a hierarchy can be extracted from the data analysis, a nested indexing structure can be created to access relevant information at a specific level of detail. Accordingly, a query can be made very specific in relationship to the level of detail that is required by the user. In order to construct the hierarchy, we describe how to extract information content from audio-visual sequences so as to have different hierarchical indicators (or descriptors), which can be associated to each media (audio, video). At this stage, video and audio signals can be separated into temporally consistent elements. At the lowest level, information is organised in frames (groups of pixels for visual information, groups of consecutive samples for audio information). At a higher level, low-level consistent temporal entities are identified: in case of digital image sequences, these consist of shots (or continuous camera records) which can be obtained by detecting cuts or special effects such as dissolves, fade in
and fade out; in case of audio information, these represent consistent audio segments belonging to one specific audio type (such as speech, music, silence, ...). One more level up, patterns of video shots or audio segments can be recognised so as to reflect more meaningful structures such as dialogues, actions, ... At the highest level, information is organised so as to establish correlation beyond the temporal organisation of information, allowing to reflect classes of visual or audio types: we call these classes idioms. The paper ends with a
description of possible solutions to allow a cross-modal analysis of audio and video information, which may validate or invalidate the proposed hierarchy, and in some cases enable more sophisticated levels of representation of information content
Audio as a Support to Scene Change Detection and Characterization of Video Sequences
No full textA challenging problem to construct video databases is the organization of video information. The development of algorithms able to organize video information according to semantic content of the data is getting more and more important. This will allow algorithms such as indexing and retrieval to work more efficiently. Until now, an attempt to extract semantic information has been performed using only video information. As a video sequence is constructed from a 2-D projection of a 3-D scene, video processing has shown its limitations especially in solving problems such as object identification or object tracking, reducing the ability to extract semantic characteristics. A possibility to overcome the problem is to use additional information. The associated audio signal is then the most natural way to obtain this information. This paper presents a technique which combines video and audio information together for classification and indexing purposes. The classification is performed on the audio signal; a general framework that uses the results of such classification is then proposed for organizing video information
Crescita territoriale e industrializzazione nell'azione meridionalista di Pasquale Saraceno
No full textScene Break Detection: A Comparison
No full textThe automatic organization of video databases according to the semantic content of data is a key aspect for efficient indexing and fast retrieval of audio-visual material. In order to generate indices that can be used to access a video database, a description of each video sequence is necessary. The identification of objects present in a frame and the track of their motion and interaction in space and time, is attractive but not yet very robust. For this reason, since the early 90's, attempts have been applied in trying to segment a video in shots. For each shot a representative frame of the shot, called k-frame, is usually chosen and the video can be analysed through its k-frames.
Even if abrupt scene changes are relatively easy to be detected, it is more difficult to identify special effects, such as dissolve, that were operated in the editing stage to merge two shots. Unfortunately, these special effects are normally used to stress the importance of the scene change (from a content point of view), so they are extremely relevant therefore they should not be missed. Beside, it is very important to determine precisely the beginning and the end of the transition in the case of dissolves and fades. In this work, two new parameters are proposed. These characterize the precision of boundaries of special effects when the scene change involves more than two frames. They are combined with the common recall and precision parameters. Three for cut detection are considered: histogram-based, motion-based and contour-based. These algorithms are tested and compared on several video sequences. Results will show that the best performance is achieved by the global histogram-based method which uses color information
Per una nuova edizione dei "Georgica" di Nicandro di Colofone
No full textMy doctoral dissertation deals with Nicander of Colophon's "Georgica". The first chapter examines author's life and the inconsistencies between ancient sources, which lead to postulate the existence of two different Nicanders, Nicander the Elder and Nicander the Younger. In the second chapter the "Georgica" and the main source of the fragments, Athenaeus of Naucratis' "Deipnosophists", are examined. Then the critical text of the fragments follows, with apparatus, translation, and notes
Chapter Caterina Colombini, o della cugina sedotta. Una ‘ricostruzione’ della figura di Caterina attraverso i testi
No full textIn this essay the author demonstrates that it is possible to “reconstruct” the figure of Caterina Colombini (1340?-1387) – Giovanni Colombini’s cousin – through a group of texts: the hagiography of Caterina, the letters sent to her by Giovanni Colombini and, finally, Giovanni’s biography written by Feo Belcari. The author divides his text into four parts: the first part analyzes the content of Caterina’s hagiography; the second examines the linguistic form of the hagiographic text; in the third, the author analyzes the latent meaning of the window, a symbolic place where Giovanni and Caterina converse on divine topics; in the last part, to conclude, the teachings that Giovanni gives to Catherine and her spiritual daughters – the Gesuate – are analyzed
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