Abstract This paper explores the design, implementation and evaluation of context-aware mobile multimedia services by presenting six case studies on different application domains. The case studies highlight the opportunities that mobile devices equipped with wireless data transmission provide for context-aware and ubiquitous computing. Special emphasis is placed on empirical evaluation of the services in the field in form of a user... This paper explores the design, implementation and evaluation of context-aware mobile multimedia services by presenting six case studies on different application domains. The case studies highlight the opportunities that mobile devices equipped with wireless data transmission provide for context-aware and ubiquitous computing. Special emphasis is placed on empirical evaluation of the services in the field in form of a user evaluation with genuine end users in real environment of use. The paper concludes with a discussion on some important lessons learned from the case studies. Read More Read Less

Abstract Nowadays, mobile devices have implemented several transmission technologies which enable access to the Internet and increase the bit rate for data exchange. Despite modern mobile processors and high-resolution displays, mobile devices will never reach the stage of a powerful notebook or desktop system (for example, due to the fact of battery powered CPUs or just concerning the small-sized displays). Due... Nowadays, mobile devices have implemented several transmission technologies which enable access to the Internet and increase the bit rate for data exchange. Despite modern mobile processors and high-resolution displays, mobile devices will never reach the stage of a powerful notebook or desktop system (for example, due to the fact of battery powered CPUs or just concerning the small-sized displays). Due to these limitations, the deliverable content for these devices should be adapted based on their capabilities including a variety of aspects (e.g., from terminal to network characteristics). These capabilities should be described in an interoperable way. In practice, however, there are many standards available and a common mapping model between these standards is not in place. Therefore, in this paper we describe such a mapping model and its implementation aspects. In particular, we focus on the whole delivery context (i.e., terminal capabilities, network characteristics, user preferences, etc.) and investigated the two most prominent state-of-the-art description schemes, namely User Agent Profile (UAProf) and Usage Environment Description (UED). Read More Read Less

Abstract Mobile guide applications are among the most used applications in Today’s smartphones. These applications provide position information, map, directory services as well as guidance. Still there are many multimedia features that could be added to these applications. We present a user study on such applications, comparing the commercial Google Maps and Nokia Maps with two prototypes that we have created... Mobile guide applications are among the most used applications in Today’s smartphones. These applications provide position information, map, directory services as well as guidance. Still there are many multimedia features that could be added to these applications. We present a user study on such applications, comparing the commercial Google Maps and Nokia Maps with two prototypes that we have created to expose missing multimedia features in the commercial applications. We have evaluated the applications with real users and we have obtained direct feedback via questionnaires as well as implicit feedback using an observer frameworrk. Read More Read Less

Abstract Consuming mobile TV services is becoming increasingly popular. As hand held devices are personal and used in a “lean-forward” mode, they are well suited for interactive TV. The porTiVity system provides authoring tools for mobile interactive content that allow attaching interactivity to moving objectsin a TV program. We describe automatic and semi-automatic annotation tools that create content descriptions represented as... Consuming mobile TV services is becoming increasingly popular. As hand held devices are personal and used in a “lean-forward” mode, they are well suited for interactive TV. The porTiVity system provides authoring tools for mobile interactive content that allow attaching interactivity to moving objectsin a TV program. We describe automatic and semi-automatic annotation tools that create content descriptions represented as MPEG-7 documents. The descriptions of moving objects are then transformed into MPEG-4 LASeR, which is a suitable lightweight format for visualization and interactivity on the mobile device. Since mobile devices are well suited for consuming personalized services we describe different personalization aspects. We show the use of the authoring components of porTiVity in two example scenarios. Read More Read Less

Abstract This paper presents a standards-based architecture for a complex and generic distributed multimedia scenario, which combines content search and retrieval, DRM, and context-based content adaptation together. It is an innovative and totally generic approach trying to narrow the semantic-gap by integrating a flexible language for multimedia search based on MPEG Query Format (MPQF) standard with the application of video analysis... This paper presents a standards-based architecture for a complex and generic distributed multimedia scenario, which combines content search and retrieval, DRM, and context-based content adaptation together. It is an innovative and totally generic approach trying to narrow the semantic-gap by integrating a flexible language for multimedia search based on MPEG Query Format (MPQF) standard with the application of video analysis algorithms for the automatic extraction of lowlevel features and with the use of contextual information. Read More Read Less

Abstract The last detailed review of Content-based Image Retrieval Systems (CBIRS) is that from Veltkamp and Tanase [VT02], updated in 2002. Since then, many new systems emerged, other systems were improved, but many systems are no longer supported. This paper reconsiders the systems described by Veltkamp and Tanase and proposes in addition for a selection of existing CBIRS a quantitative comparison.... The last detailed review of Content-based Image Retrieval Systems (CBIRS) is that from Veltkamp and Tanase [VT02], updated in 2002. Since then, many new systems emerged, other systems were improved, but many systems are no longer supported. This paper reconsiders the systems described by Veltkamp and Tanase and proposes in addition for a selection of existing CBIRS a quantitative comparison. For this purpose we developed a benchmarking system for CBIRS based on how accurate they could match ideal (ground truth) results. As measure we introduced the RankWRN , which we developed based on the Normalized Avarage Rank. Our measure allows fair and accurate comparisons (due to multiple similarity values) of different CBIRS with respect to different queries. None of the other benchmarks allow this comparison. The choice for a system to be compared quantitatively was motivated by availability of the source or runtime code and the liveness (i.e., active development on the CBIRS). The benchmarked systems were SIMBA, SIMPLIcity, PictureFinder, ImageFinder, Caliph&Emir, VIPER/GIFT and Oracle Intermedia. Results show that VIPER/GIFT performs best in the settings of our benchmark, Caliph&Emir is second and SIMBA third. The default parameter settings of the systems tend to show the best results. MPEG-7 descriptors, which are used in Caliph&Emir, show a good performance in the benchmarking. Read More Read Less