An Overview of Multimodal Techniques for the Characterization of Sport Programmes

The problem of content characterization of sports videos is of great interest because sports video appeals to large audiences and its efficient distribution over various networks should contribute to widespread usage of multimedia services. In this paper we analyze several techniques proposed in literature for content characterization of sports videos. We focus this analysis on the typology of the signal (audio, video, text captions, ...) from which the low-level features are extracted. First we consider the techniques based on visual information, then the methods based on audio information, and finally the algorithms based on audio-visual cues, used in a multi-modal fashion. This analysis shows that each type of signal carries some peculiar information, and the multi-modal approach can fully exploit the multimedia information associated to the sports video. Moreover, we observe that the characterization is performed either considering what happens in a specific time segment, observing therefore the features in a "static" way, or trying to capture their "dynamic" evolution in time. The effectiveness of each approach depends mainly on the kind of sports it relates to, and the type of highlights we are focusing on

State-of-the-Art and Trends in Scalable Video Compression with Wavelet Based Approaches

3noScalable Video Coding (SVC) differs form traditional single point approaches mainly because it allows to encode in a unique bit stream several working points corresponding to different quality, picture size and frame rate. This work describes the current state-of-the-art in SVC, focusing on wavelet based motion-compensated approaches (WSVC). It reviews individual components that have been designed to address the problem over the years and how such components are typically combined to achieve meaningful WSVC architectures. Coding schemes which mainly differ from the space-time order in which the wavelet transforms operate are here compared, discussing strengths and weaknesses of the resulting implementations. An evaluation of the achievable coding performances is provided considering the reference architectures studied and developed by ISO/MPEG in its exploration on WSVC. The paper also attempts to draw a list of major differences between wavelet based solutions and the SVC standard jointly targeted by ITU and ISO/MPEG. A major emphasis is devoted to a promising WSVC solution, named STP-tool, which presents architectural similarities with respect to the SVC standard. The paper ends drawing some evolution trends for WSVC systems and giving insights on video coding applications which could benefit by a wavelet based approach.partially_openpartially_openADAMI N; SIGNORONI. A; R. LEONARDIAdami, Nicola; Signoroni, Alberto; Leonardi, Riccard

Constrained energy minimization and ground states for NLS with point defects

We investigate the ground states of the one-dimensional nonlinear Schr\"odinger equation with a defect located at a fixed point. The nonlinearity is focusing and consists of a subcritical power. The notion of ground state can be defined in several (often non-equivalent) ways. We define a ground state as a minimizer of the energy functional among the functions endowed with the same mass. This is the physically meaningful definition in the main fields of application of NLS. In this context we prove an abstract theorem that revisits the concentration-compactness method and which is suitable to treat NLS with inhomogeneities. Then we apply it to three models, describing three different kinds of defect: delta potential, delta prime interaction, and dipole. In the three cases we explicitly compute ground states and we show their orbital stability. This problem had been already considered for the delta and for the delta prime defect with a different constrained minimization problem, i.e. defining ground states as the minimizers of the action on the Nehari manifold. The case of dipole defect is entirely new.Comment: 35 pages, 3 figure

Transforming Multimedia Structural Information into Semantics

In this paper a new approach to metadata production is presented. For this purpose, a new interactive tool for audiovisual content acquisition and classication has been developed. The user can decompose a given content into units and easily annotate each unit adding basic information such as time, place, etc. as well classication information such as event type, relationship type, etc. according to the MPEG 7 Standard. At the end of this production process, the tool automatically produces a structural description of the overall set of the annotated units. The new idea proposed in this work is to combine the intrinsic semantics of each annotated unit with the implicit semantic information derived from the structural description, hence reducing the needs to perform complex signal processing operations on the content. This aspect is really important since image and video processing is generally heavier than metadata processing and the content can be spread over a network and not made readily available at the processing point

A fully scalable wavelet video coding scheme with homologous inter-scale prediction

In this paper, we present a fully scalable wavelet-based video coding architecture called STP-Tool, in which motion-compensated temporal-filtered subbands of spatially scaled versions of a video sequence can be used as a base layer for inter-scale predictions. These predictions take place in a pyramidal closed-loop structure between homologous resolution data, i.e., without the need of spatial interpolation. The presented implementation of the STP-Tool architecture is based on the reference software of the Wavelet Video Coding MPEG Ad-Hoc Group. The STP-Tool architecture makes it possible to compensate for some of the typical drawbacks of current wavelet-based scalable video coding architectures and shows interesting objective and visual results even when compared with other wavelet-based or MPEG-4 AVC/H.264-based scalable video coding systems

Progressive contour coding in the wavelet domain

This paper presents a new wavelet-based image contour coding technique, suitable for representing either shapes or generic contour maps. Starting from a contour map (e.g. a segmentation map or the result of an edge detector process), a unique one-dimensional signal is generated from the set of contour points. Coordinate jumps between contour extremities when under a tolerance threshold represent signal discontinuities but they can still be compactly coded in the wavelet domain. Exceeding threshold discontinuities are coded as side information. This side information and the amount of remaining discontinuity are minimized by an optimized contour segment sequencing. The obtained 1D signal is decomposed and coded in the wavelet domain by using a 1D extension of the SPIHT algorithm. The described technique can efficiently code any kind of 2D contour map, from one to many unconnected contour segments. It guarantees a fully embedded progressive coding, state-of-art coding performance, good approximation capabilities for both open and closed contours, and graceful visual degradation at low bit-rates

SVC CE1: STool - a native spatially scalable approach to SVC

4noThis documents describes the UNIBS-SCL proposal in response to the MPEG21 SVC CE1 [1]. Our scalable video coding scheme, called STool, is based on a 2D+t+2D structure and is implemented using a modified version of the Microsoft Research Asia (MSRA) reference software [2] plus some modifications and tools which has been used in substitution. The STool architecture has been implemented in two different systems. In System-1 the modules provided in the MSRA software have been used to build the new STool architecture. In System-2 we test a new entropy coder, called GOF-EMDC, which is an extended version of the EMDC coder [3]. At the time GOF-EMDC codec and other parts of System-2 have not been optimized in many aspects, therefore we can expect better performance from our system in the next future. Despite this fact System-2 provides similar coding performances when compared to System-1. In addition, System-2 is much more flexible in many aspects, it guarantees a major number of functionalities and better fulfill the requirements list. Therefore with System-1 we intend to demonstrate the characteristics of the STool architecture, especially with respect to the reference software used, while with System-2 we customize and add functionalities to Stool. We submitted extraction and decoding software for both Systems-1 and System-2, System-1 coded sequences for both scenarios 1 and 2 and System-2 coded sequences for scenario 2 only. For System-2 scenario 1 we only had deadline problems. No technical problems actually exist to produce such sequences.ISO/IEC JTC1/SC29/WG11 MPEG2004/M11368 70th meeting, Oct. 2004, Palma de Mallorca, ESopenopenADAMI N.; BRESCIANINI M.; LEONARDI R; SIGNORONI A.Adami, Nicola; Brescianini, Michele; Leonardi, Riccardo; Signoroni, Albert

Markov Chains Fusion for Video Scene Generation

In this paper we address the general issue of merging Markov chains used to model two instances of a given process with some properties in common. In particular, in this work we apply this scenario to a multimedia application that generates new video scenes mixing the original segments of a given movie. To perform the latter process, it is first necessary to describe the structure of the scenes in some way, which in our case is done through Markov chains. The video scenes are then recombined by fusing their corresponding models using the general method described here. We analyze and validate the proposed methodology only for this specific application, however the solution presented here could be used in a very diverse array of applications where Markov chains are routinely used, ranging from queuing modeling to financial decision processes

HDR Image Watermarking

In this Chapter we survey available solutions for HDR image watermarking. First, we briefly discuss watermarking in general terms, with particular emphasis on its requirements that primarily include security, robustness, imperceptibility, capacity and the availability of the original image during recovery. However, with respect to traditional image watermarking, HDR images possess a unique set of features such as an extended range of luminance values to work with and tone-mapping operators against whom it is essential to be robust. These clearly affect the HDR watermarking algorithms proposed in the literature, which we extensively review next, including a thorough analysis of the reported experimental results. As a working example, we also describe the HDR watermarking system that we recently proposed and that focuses on combining imperceptibility, security and robustness to TM operators at the expense of capacity. We conclude the chapter with a critical analysis of the current state and future directions of the watermarking applications in the HDR domain

Metodo di codifica video scalabile

4noUn metodo di codifica video scalabile in cui il segnale video viene elaborato e codificato a diversi livelli di risoluzione spaziale dove tra coppie di livelli spaziali viene abilitato un meccanismo di predizione che consente un confronto a livelli di risoluzione spaziale omologhi senza impedire che vengano persi dati utili al fine di ottenere una buona efficienza di codifica.openopenADAMI N.; BRESCIANINI M.; R. LEONARDI; SIGNORONI A.Adami, Nicola; Brescianini, Michele; Leonardi, Riccardo; Signoroni, Albert