Can small be beautiful?: assessing image resolution requirements for mobile TV

Mobile TV services are now being offered in several countries, but for cost reasons, most of these services offer material directly recoded for mobile consumption (i.e. without additional editing). The experiment reported in this paper, aims to assess the image resolution and bitrate requirements for displaying this type of material on mobile devices. The study, with 128 participants, examined responses to four different image resolutions, seven video encoding bitrates, two audio bitrates and four content types. The results show that acceptability is significantly lower for images smaller than 168x126, regardless of content type. The effect is more pronounced when bandwidth is abundant, and is due to important detail being lost in the smaller screens. In contrast to previous studies, participants are more likely to rate image quality as unacceptable when the audio quality is high.

[1]  Byron Reeves,et al.  The effects of screen size and message content on attention and arousal Media Psychology , 1999 .

[2]  V. Dreyer,et al.  Visual acuity. , 1974, Ophthalmologica. Journal international d'ophtalmologie. International journal of ophthalmology. Zeitschrift fur Augenheilkunde.

[3]  William Buxton,et al.  Telepresence: Integrating Shared Task and Person Spaces , 1992 .

[4]  Rahim Tafazolli,et al.  S-DMB System Architecture and the MoDiS Demo , 2004, Broadband Satellite Comunication Systems.

[5]  D. Snydacker,et al.  Adler's Physiology of the Eye. Clinical Application , 1981 .

[6]  Sugato Chakravarty,et al.  Methodology for the subjective assessment of the quality of television pictures , 1995 .

[7]  Stefan Winkler,et al.  Audiovisual quality evaluation of low-bitrate video , 2005, IS&T/SPIE Electronic Imaging.

[8]  Clifford Nass,et al.  The media equation - how people treat computers, television, and new media like real people and places , 1996 .

[9]  Richard Weiner.  Webster's New World dictionary of media and communications , 1990 .

[10]  D. S. Hands,et al.  A basic multimedia quality model , 2004, IEEE Transactions on Multimedia.

[11]  Yutaka Matsushita,et al.  Multiparty videoconferencing at virtual social distance: MAJIC design , 1994, CSCW '94.

[12]  U. Reimers,et al.  Digital video broadcasting , 1998, IEEE Commun. Mag..

[13]  M. Angela Sasse,et al.  Sharp or smooth?: comparing the effects of quantization vs. frame rate for streamed video , 2004, CHI '04.

[14]  M. Angela Sasse,et al.  Do Users Always Know What's Good For Them? Utilising Physiological Responses to Assess Media Quality , 2000, BCS HCI.

[15]  Stefan Winkler,et al.  Video quality evaluation for mobile streaming applications , 2003, Visual Communications and Image Processing.

[16]  Christof Faller,et al.  MAXIMIZING AUDIOVISUAL QUALITY AT LOW BITRATES , 2005 .

[17]  P. ed Hoschka,et al.  synchronized Multimedia Integration Language (SMIL) 1.0 Specification , 1998 .

[18]  Greger Wikstrand,et al.  Determining utility functions for streaming low bit rate football video , 2004 .

[19]  Daniel B. Horn,et al.  The effects of spatial and temporal video distortion on lie detection performance , 2002, CHI Extended Abstracts.

[20]  D A Owens,et al.  Near work, visual fatigue, and variations of oculomotor tonus. , 1987, Investigative ophthalmology & visual science.

[21]  Luke D. Postema,et al.  The Institute of Electrical and Electronics Engineers , 1963, Nature.

[22]  V. Michael Bove,et al.  Television Sound and Viewer Perceptions , 1991 .

[23]  R. Jain.  Quality of experience , 2004, IEEE MultiMedia.

[24]  Caj Södergård,et al.  Mobile television - technology and user experiences: Report on the Mobile-TV project , 2003 .

[25]  John G. Beerends,et al.  The Influence of Video Quality on Perceived Audio Quality and Vice Versa , 1999 .

[26]  M. Angela Sasse,et al.  Why Value Is Everything: A User-Centered Approach to Internet Quality of Service and Pricing , 2001, IWQoS.