F. Moschetti

NTT DOCOMO, Edo, Tōkyō, Japan

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Publications (22)9.75 Total impact

  • F. Moschetti, K. Sugimoto, S. Kato, M. Etoh
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    ABSTRACT: In this paper we present a video coder based on a redundant dictionary that employs nonseparable bidimensional functions. The algorithm used for the representation of the residual of motion estimation is matching pursuit (MP). The proposed dictionary has new features capable of catching curved and oriented contours typical of the residual of motion estimation in natural video sequences. An adaptive grid approach is adopted for the coding of atoms and this is combined with an innovative coding method employing an arithmetic encoder. The proposed coder shows improvements over H.264 in terms of compression efficiency, with up to 20% gains for very low bitrates.
    Image Processing, 2004. ICIP '04. 2004 International Conference on; 11/2004
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    ABSTRACT: Video coding schemes, equipped with various kinds of prediction modes, improve coding efficiency by offering efficient prediction modes that adapt to the motion in a macroblock (MB). Operation time for motion estimation and mode selection, on the other hand, increases with the number of prediction modes. We have proposed a motion compensated prediction method (arbitrary-shape partitioning motion compensation: APMC) equipped with various inter prediction modes which adapts to the motion boundary of objects on an MB basis. This paper confirms the coding efficiency of APMC in comparison to the final specification of H.264/AVC and introduces a method to improve the computational performance of APMC by using a hierarchical mode search method based on motion boundary position within MBs. Simulation results show that APMC improves coding efficiency by about 5% in comparison with the final specification of H.264/AVC, and the proposed hierarchical mode search method decreases the operation time to about 60%, while maintaining the coding efficiency.
    Image Processing, 2004. ICIP '04. 2004 International Conference on; 11/2004
  • F. Moschetti, K. Sugimoto, S. Kato, M. Burrini
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    ABSTRACT: Wavelets, fundamental components of the latest image coding standard JPEG2000, have proven to be a very useful tool in representation and coding of 2D images. They are also a powerful instrument in catching zero-dimensional singularities, though less efficient in dealing with 'edge' singularities. Ridgelets, by definition, are a powerful tool in catching and representing line singularities in bidimensional space. In this paper we propose a hybrid approach that combines both ridgelets and wavelets for a more efficient representation of 2D images with edges. Results confirm the potential of the combined use of wavelets and ridgelets as an efficient representation, showing substantial improvements when compared to only wavelets.
    Acoustics, Speech, and Signal Processing, 2004. Proceedings. (ICASSP '04). IEEE International Conference on; 06/2004
  • K. Sugimoto, F. Moschetti, S. Kato, M. Etoh
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    ABSTRACT: Matching pursuit (MP) based video coder represents an active alternative to conventional block based DCT based architectures R Neff et al. (1997). In this paper we propose a generalized motion compensation method and an entropy coding method for MP based coder. Motion vectors are combined with the cut-off frequency level of loop filters applied to the reference frame. Exploiting the characteristics of MP atoms, the latter are efficiently coded by employing an adaptive grid size combined with context based adaptive arithmetic coder. Reordering of atoms in each grid is also applied. Simulation results show that our proposed method outperforms traditional fixed grid based approach.
    Image Processing, 2003. ICIP 2003. Proceedings. 2003 International Conference on; 10/2003
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    L. Granai, F. Moschetti, P. Vandergheynst
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    ABSTRACT: Wavelet transform is a powerful instrument in catching zero-dimensional singularities. Ridgelets are powerful instrument in catching and representing mono-dimensional singularities in bidimensional space. In this paper we propose a hybrid video coder scheme using ridgelet transform for the first approximation of line-edge singularities in displaced frame difference images. We demonstrate the potential of ridgelets and results show substantial improvements when compared to wavelet only based coder.
    Multimedia and Expo, 2003. ICME '03. Proceedings. 2003 International Conference on; 08/2003
  • F. Moschetti, M. Kunt, E. Debes
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    ABSTRACT: We address the problem of motion estimation (ME) in digital video sequences and propose a new fast, adaptive, and efficient block-matching algorithm. Higher quality and efficiency are achieved using a statistical model for the motion vectors. This model introduces adaptation in the search window, drastically reducing the number of positions where correlation-type computation is performed. The efficiency is further improved by progressively undersampling the macroblock. Patterns for undersampling are proposed to obtain the maximum benefit from single instruction multiple data (SIMD) instructions. In contrast with existing motion-estimation techniques, search strategy and subsampled patterns are closely linked. This shows that a good search strategy is much more important than blindly reducing the number of pixels considered for the matching pattern. We describe an implementation of the proposed matching strategy that exploits the very long instruction word (VLIW) and SIMD technology available in the new Itanium processor family. Results show that the proposed algorithm adapts easily to the evolution of the scene avoiding annoying quality drops that can be observed with other deterministic algorithms. The total number of operations required by the proposed method is inferior to those required by traditional approaches.
    IEEE Transactions on Circuits and Systems for Video Technology 06/2003; DOI:10.1109/TCSVT.2003.811363 · 2.26 Impact Factor
  • Fulvio Moschetti, Kazuo Sugimoto
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    ABSTRACT: Achieving very low bitrates for video applications in a mobile environment is essential. Video codecs standards evolution had a tremendous impact in the development of digital video, making possible today widespread usage of video data. At the same time it had an impact on the direction of research, biasing most of the efforts towards block based video. Alternative approaches may though lead towards different architectures able to provide higher compression efficiency. In this paper we propose a Matching Pursuit (MP) based video coder that adopts a generalized sub-pixel motion compensation and arithmetic coding. We introduce a new dictionary, and an adaptive grid for atom coding combined with an arithmetic coder. Comparison with H.264 show an improvement of up to 20% in compression efficiency for the same PSNR
    Visual Communications and Image Processing 2003; 01/2003
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    ABSTRACT: Matching pursuit decomposes a signal into a linear expansion of functions selected from a redundant dictionary, isolating the signal structures that are coherent with respect to a given dictionary. In this paper we focus on the Matching Pursuit representation of the displaced frame difference (dfd). In particular, we introduce a new dictionary for matching pursuit that efficiently exploits the signal structures of the dfd. We also propose a fast strategy to find the atoms exploiting the maximum of the absolute value of the error in the motion predicted image and the convergence of the MSE with the rotation of the atoms. Results show that the fast strategy is quite robust when compared to exhaustive search techniques and it improves the results of a suboptimal search strategy based on a genetic algorithm.
    Image Processing. 2002. Proceedings. 2002 International Conference on; 02/2002
  • F. Moschetti, G. Covitto, F. Ziliani, A. Mecocci
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    ABSTRACT: We describe a system for automatic objects extraction and dynamic bitrate allocation in a second generation object based video coder, targeting surveillance sequences. We combine model-based statistical change detection with a multiresolution-based approach for object extraction. Masks are redefined at a block level resolution and refined to improve the coding quality exploiting spatio-temporal considerations. We propose a dynamic adaptation of the quantization step of the MPEG-4 coder, based on motion information of the extracted objects. The results outperform traditional frame based coders at very low bit-rates. The masks proposed dramatically improve the coding performance, even when compared to ideally extracted masks.
    Multimedia and Expo, 2002. ICME '02. Proceedings. 2002 IEEE International Conference on; 02/2002
  • Eric Debes, Fulvio Moschetti
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    ABSTRACT: This paper proposes a classification of the parallelisms in general-purpose processor based systems in three main categories. One category is the intra-processor parallelism that includes multimedia instructions and superscalar and VLIW architectures. The former takes advantage of data parallelism. The latter benefit from instruction level parallelism. Another category is the inter-processor parallelism. We consider the parallelism between processors inside shared memory symmetric multiprocessor systems and in distributed memory clusters of workstations. Finally, in the last category, main features of the system level parallelism are studied including the input/output operations, the memory hierarchy and the exploitation of external processing. The potential gain is studied for each type of parallelism available in general-purpose processor based systems from a theoretical point of view as well as for existing image and video applications. The results in this paper showed that the exploitation of the different levels of parallelism available in PC workstations can lead to considerable gains in speed when optimizing a multimedia application. Finally the results of this work can be used to influence the design of new multimedia systems and media processors.
    Visual Communications and Image Processing 2002; 01/2002
  • Fulvio Moschetti, Eric Debes
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    ABSTRACT: ABSTRACT When a block matching must be performed between two frames, the matching,criterion is usually evaluated using every pixel of the block. One of the fundamental,hypothesis of block matching (BM) is that all the pixels in a block move,with the same motion vector. According to this hypothesis, a good estimation of the motion,could be obtained,by using,only a fraction of the pixels ina,block for the computation ,of the ,correlation. It is evident anyway that if too few pixels are used to get this match, then there will be an inaccuracy in the motion estimates. Inthis paper we study ,the impact ,of particular ,subsampling
    Proceedings of the 2001 IEEE International Conference on Multimedia and Expo, ICME 2001, August 22-25, 2001, Tokyo, Japan; 01/2001
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    Fulvio Moschetti, Eric Debes
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    ABSTRACT: Motion estimation represents the main computational burden of every hybrid video encoder. Various solutions have been proposed in order to reduce the number of operations needed for this task, trying to keep good quality of the estimation and of the relative encoded video. In this paper we propose an algorithm that, exploiting the statistical properties of the motion field, searches a number of points dynamically related to the evolution of the sequence. A subsampling pattern of the Macroblock is also proposed to reduce the overall impact of the motion estimation in an MPEG encoder. Keywords: Motion estimation, dynamic adaptation, Macroblock subsampling, MPEG 1. INTRODUCTION Digital video communications is a field that, in last years, was characterized by an exponential growth and it keeps on evolving thanks to the continuously increasing bandwidth availability and the enormous interest in video communications, video e-mail and e-commerce applications like video ads on the web. The ...
    Proceedings of SPIE - The International Society for Optical Engineering 06/2000; DOI:10.1117/12.386554 · 0.20 Impact Factor
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    L. Favalli, A. Mecocci, F. Moschetti
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    ABSTRACT: The work presented in this article describes a tool for object tracking, notes insertion, and information retrieval, applicable to MPEG-2 sequences. Maximum compliance with the MPEG standard is sought, so the added information is transmitted as side information without affecting the actual video-audio stream as defined in the MPEG-2 standard. Additional processing is added to a standard sequence, allowing for automatic tracking of one object across different groups of pictures. Results show that the proposed algorithm is capable of tracking objects with a good degree of precision. Features are included to alert the human operator when objects disappear, or must be considered lost, due to an excessive change in their shape
    IEEE Transactions on Circuits and Systems for Video Technology 05/2000; 10(3-10):427 - 432. DOI:10.1109/76.836288 · 2.26 Impact Factor
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    F. Moschetti, E. Debes
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    ABSTRACT: A new block matching (BM) algorithm for motion estimation (ME) is introduced in this paper. This algorithm is formed of two different steps: the first step considers, inside the search window, a fewer number of pixels rather than the full search algorithm (FSA); the second step considers a sub-sampled macroblock (MB) for the operations that contribute to determine the mean absolute difference (MAD). The sub-sampling technique is meant to exploit as much as possible the single instruction multiple data (SIMD) technique currently available on the most common general purpose processors. The overall number of operations needed to compute the BM is considerably reduced. The simulations results of the proposed algorithm compared with the conventional methods are given. The proposed technique shows an improvement in terms of number of operations required and for the PSNR and MPQM behavior, for MPEG2 encoded sequences
    Circuits and Systems, 2000. Proceedings. ISCAS 2000 Geneva. The 2000 IEEE International Symposium on; 02/2000
  • F. Moschetti, M. Kunt, F. Calvano
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    ABSTRACT: In this paper we propose a block matching algorithm (BM) that reduces the computational burden of the motion estimation in an hybrid video encoder. To decrease the global complexity it acts at three different levels represented by the frame itself, the searching window and the macroblock (MB). To achieve an optimal performance also onto current general purpose processors provided with SIMD register files, a particular sub-sampling pattern of the MB is used. The algorithm shows a lower complexity than the three step search (TSS). In sequences where the motion field is formed by large motion vectors, the quality performance can be better than the full search algorithm (FSA) with an a priori fixed maximum motion vector. The algorithm is in fact able to adapt itself to the sequence
    Image Processing, 2000. Proceedings. 2000 International Conference on; 02/2000
  • E. Debes, F. Moschetti
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    ABSTRACT: This article presents a new model for the exploitation of the different levels of parallelism in general purpose processor based workstations in the framework of multimedia applications. It is called the GEMS model, standing for gain, effort, management and size. It is used to study the intra-processor parallelism including instruction level and data level parallelism, inter-processor parallelism ranging from shared-memory multiprocessors to distributed memory clusters and system level parallelism like input/output operations and the exploitation of external resources. The aim of this work is to help a programmer writing a multimedia application in choosing which level of parallelism will help to speed up the application and how to partition the application into small tasks to obtain the highest gain for a given parallelism. Indeed for an efficient implementation it is very important to have a good understanding of the architecture in order to design new algorithms or to optimize an existing application according to features available in PC workstations
    Multimedia and Expo, 2000. ICME 2000. 2000 IEEE International Conference on; 02/2000
  • Eric Debes, Fulvio Moschetti
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    ABSTRACT: Cet article explique comment des logiciels multimédia qui nécessitent beaucoup de ressources peuvent s'exécuter de manière satisfaisante sur des stations de travail à base de processeurs généralistes, sans matériel spécifique, grâce à des changements algorithmiques et à l'adaptation de l'implémentation aux architectures PCs. L'encodeur MPEG2 est pris comme exemple pour décrire la méthodologie qui a pour but d'exécuter l'application le plus rapidement possible sur une station de travail PC. Afin d'atteindre cet objectif, nous montrons comment obtenir les gains en vitesse grâce à une technique de comparaison de blocs différente de celle de la recherche exhaustive et grâce à l'exploitation des différents niveaux de parallélisme disponibles dans les machines à base de processeurs généralistes. Les résultats démontrent un gain considérable en vitesse tout en conservant une qualité acceptable du bitstream vidéo décodé.
  • L. Favalli, A. Mecocci, F. Moschetti
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    ABSTRACT: The work presented in this paper describes a tool for object tracking and notes insertion and information retrieval to be applied to MPEG-2 sequences. Maximum compliance with the MPEG standard is sought, in that the added information is transmitted as side information without affecting the actual video-audio stream that can be decoded by a standard MPEG-2 decoder. Additional processing is added to a standard encoder only with the scope to allow the automatic tracking of one object across a different Group of Pictures which would be otherwise unrelated. Results show that the proposed algorithm is capable of tracking objects with a good degree of precision for about 100 frames. Features are included to allow the identification of objects even after occlusions, provided that some (reasonable) restrictions are met
    Circuits and Systems, 1998. ISCAS '98. Proceedings of the 1998 IEEE International Symposium on; 01/1998
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    Eric Debes, Fulvio Moschetti
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    ABSTRACT: Le but de cet article est d'expliquer comment exploiter efficacement les différents niveaux de parallélisme disponibles dans les systèmes à base de processeurs généralistes pour l'implémentation d'applications multimédias. Les différents parallélismes sont classés en trois niveaux : intra-processeur, inter-processeur et au niveau du système. L'exploitation des différents niveaux de parallélisme est étudiée du point de vue théorique ainsi que par des exemples pratiques en soulignant le gain potentiel, l'effort requis par le programmeur, le management du niveau de parallélisme et la taille idéale des données à traiter en parallèle. Un modèle d'étude des différents niveaux de parallélisme est proposé pour aider le programmeur à choisir quelles fonctionnalités permettent d'obtenir le meilleur gain en vitesse d'exécution avec le minimum d'effort de programmation et de temps de développement. De plus le temps nécessaire au management du parallélisme ainsi que la taille idéale des données à traiter en parallèle sont expliqués pour aider le programmeur à distribuer son application de manière efficace.
  • E. Debes, F. Moschetti