The paper focuses on testing the user perception of time-variable quality of scene objects. The scenes are generated and presented by the DMP (Distributed Multimedia Plays) packet-based system for futuristic continental multimedia collaboration. DMP guarantees maximum user-to-user delay and minimum scene quality. Time-variable scene quality control is obtained by adapting the composition and object resolution to traffic load in the network, by controlled dropping of sub-objects in network nodes, and by admission control. The perceived quality of scenes was tested using an existing DMP performance (simulation) model that generates two-dimensional random distributions for the frequency of overloads in the network nodes versus packet drop rate and duration. Video clips with time-varying scene quality were synthesized, and showed to test persons. Four sub-objects of spatial resolution 1400 x 1050 pixels, and temporal resolution of 60Hz was applied. Sub-objects were dropped in the network, and missing sub-objects were regenerated by standard linear interpolation techniques. Test persons could perceive a moderate average quality reduction 13 on a 0-100 quality scale when 75% of the sub-objects were dropped and interpolated. To improve the quality, edge detection and correction was added. The test persons could perceive a small average quality reduction of 8 on a 0-100 quality scale when 75% of the sub-objects were dropped.

Date Published: 19 January 2009
PDF: 12 pages
Proc. SPIE 7242, Image Quality and System Performance VI, 72420X (19 January 2009); doi: 10.1117/12.808512

Published in SPIE Proceedings Vol. 7242:
Image Quality and System Performance VI
Susan P. Farnand; Frans Gaykema, Editor(s)