Current Issue : January - March Volume : 2012 Issue Number : 1 Articles : 4 Articles
The earth mover's distance (EMD) is a measure of the distance between two distributions, and it has been widely used in multimedia information retrieval systems, in particular, in content-based image retrieval systems. When the EMD is applied to image problems based on color or texture, the EMD reflects the human perceptual similarities. However, its computations are too expensive to use in large-scale databases. In order to achieve efficient computation of the EMD during query processing, we have developed ââ?¬Å?fastEMD,ââ?¬Â a library for high-speed feature-based similarity retrievals in large databases. This paper introduces techniques that are used in the implementation of the fastEMD and performs extensive experiments to demonstrate its efficiency....
In contrast to what is happening in the Internet-based scenario, the music market in the mobile scenario is far from being considered a large success. Several studies state that excessive downloading time and high cost are the main burdens. Motivated by the growth of social and mobile applications, in this paper we propose an approach that aims at reducing both the downloading time and the cost to get digital music when acquired in the mobile scenario. The proposed architecture exploits the usage of personal communication technologies embedded in cellphones (e.g., Bluetooth and Wi-Fi) to couple the current distribution model (mainly based on 3G networks), so as to provide a multichannel distribution model where users are free to redistribute digital music. The architecture includes a license-based security mechanism that prevents unauthorized usage of digital music, and makes use of an incentive mechanism to stimulate and reward the music distribution among customers. By analyzing pros and cons of the music distribution chain, results show that the proposed architecture might help in reducing both the downloading time and the cost to get digital music when acquired in the mobile scenario. Therefore, it might be helpful to the success of the mobile music scenario....
To quantify the excellence of multimedia quality, subjective evaluation experiments are conducted. In these experiments, the tradition of quantitative assessment is the most dominating, but it disregards the understanding of participants' interpretations, descriptions, and the evaluation criteria of quality. The goal of this paper is to present a new multimedia quality evaluation method called Open Profiling of Quality (OPQ) as a tool for building a deeper understanding on subjective quality. OPQ is a mixed method combining a conventional quantitative psychoperceptual evaluation and qualitative descriptive quality evaluation based on the individual's own vocabulary. OPQ is targeted for na�¯ve participants applicable to experiments with heterogeneous and multimodal stimulus material. The paper presents the theoretical basis of the development of OPQ and overviews the methods for audiovisual quality research. We present three extensive quality evaluation studies where OPQ has been used with 120 participants. Finally, we conclude further recommendations of use of the method in quality evaluation research....
Traditional synchronization schemes of multimedia applications are based on temporal relationships between inter- and intrastreams. These schemes do not provide good synchronization in the presence of random delay. As a solution, this paper proposes an adaptive content-based synchronization scheme that synchronizes multimedia streams by accounting for content in addition to time. This approach to synchronization is based on the fact that having two streams sampled close in time does not always imply that these streams are close in content. The proposed scheme primary contribution is the synchronization of audio and video streams based on content. The secondary contribution is adapting the frame rate based on content decisions. Testing adaptive content-based and adaptive time-based synchronization algorithms remotely between the American University of Beirut and Michigan State University showed that the proposed method outperforms the traditional synchronization method. Objective and subjective assessment of the received video and audio quality demonstrated that the content-based scheme provides better synchronization and overall quality of multimedia streams. Although demonstrated using a video conference application, the method can be applied to any multimedia streams including nontraditional ones referred to as supermedia like control signals, haptic, and other sensory measurements. In addition, the method can be applied to synchronize more than two streams simultaneously....
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