Priority-driven coding of progressive JPEG images for transmission in real-time applications

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.