SPECIAL ISSUE ON QUALITY OF EXPERIENCE ISSUES IN MEDIA DELIVERY Quality of Experience Issues in Media Delivery

For Media delivery industry, guarantee of user experience is always a key factor for many media service to consumers. Therefore contrary to QoS, concept of QoE (Quality of Experience) has been highlighted concerns for media delivery industry referring to " the overall acceptability of an application or service, as perceived subjectively by the end user ". Media delivery industry takes end-user QoE monitoring as either " critical " or " very important " to their video initiatives, and meanwhile the top issue reported from industry is that current QoE assessment solutions deployed today are not accurate enough and too costly to measure end user experience. Therefore this E-Letter tries to provide a compact and insightful understanding on current research status on QoE, standard activities and applications related to accurate and light weight QoE assessment solutions for media delivery. The first paper, titled 'Perceptual-based visual quality metrics: Methodologies, directions and challenges', provides an overview on QoE concept, difference from QoS, existed classification, research challenges and opportunities. Visual Quality Metrics are classified according to the availability of the reference and employed methodologies. Challenges from aspect of multi-dimensional measurement, multidisciplinary processing, inadequate understanding of the human perception system, 3D content are also highlighted. Standardization is always the most efficient way to push new technologies to be adopted by industry. The second paper, titled 'Recent Multimedia QoE standardization activities in ITU-T SG12', briefly outlines recent and ongoing standardization activities of SG12 on multimedia QoE assessment. A structured figure on ITU-related standardization bodies working on multimedia QoE assessment was given in the paper. Standard activities related to speech QoE, Audio, Video and Audiovisual QoE are introduced with their latest status in the ITU-T standard group. Relation between different standard group and future outlook are also concluded in the paper. We need to clearly clarify and classify different applications scenarios when designing applicable QoE assessment schemes. The third paper, titled 'QoE Models for Quality Planning and Monitoring for Video Delivery', tries to clearly differentiate the requirements for QoE models from two typical scenarios in video delivery, namely, video system quality planning scenario and the quality monitoring scenario. Then QoE modeling approaches for the two scenarios and different criteria to construct the evaluation datasets are also illustrated in the paper. 3D video becomes more and more important in media delivery applications. The fourth paper, titled 'Objective quality assessment for 3-D video delivery', presents a brief review on …