Since high-quality image/video systems based on the JPEG/MPEG compression standards often require power-expensive implementations
at relatively high bit-rates, they have not been widely used in low-power wireless applications. To alleviate this problem,
we designed, implemented, and evaluated a strategy that can adapt to different compression and transmission rates. (1) It
gives important parts of an image higher priority over unimportant parts. Therefore, the high-priority parts can achieve high
image quality, while the low-priority parts, with a slight sacrifice of quality, can achieve huge compression rate and thus
save the power/energy of a low-power wireless system. (2) We also introduce a priority-driven scheduling approach into our
coding algorithm, which makes the transmission of important parts earlier with more data than other parts. Through a balanced
trade-off between the available time/bandwidth/power and the image quality, this adaptive strategy can satisfy users with
desired images quality and lead to a significant reduction of the important parts’ deadline misses.
Keywords image systems - video systems - JPEG/MPEG compression standards, real-time scheduling
This material is supported in part by the National Science Foundation under Award No. IRI-9526004 and by a grant from the
Institute for Space Systems Operations. A preliminary 6-page version has appeared in the Proc. 11th IEEE-CS International
Conference on Embedded and Real-Time Computing Systems and Applications, Hong Kong, Aug. 2005.