Dynamic image adaptation technique and architecture to enhance server performance in wireless image services

Image-based data services, like wireless photos with camera phones and multi-media message services, are gaining in popularity and wireless data market share. Dynamic image adaptation techniques have been shown to be effective to provide required tradeoffs between image quality, network bandwidth availability, and wireless transmission latency, enabling low-cost, best-effort wireless image data transmission (D.G. Lee et al., 2002; D.G. Lee et al., 2003). This paper investigates the effect of image adaptation techniques on image servers, including server latency and server capacity, and end-to-end service latency using a proposed performance evaluation and exploration framework. We first motivate the need for dynamic adaptation techniques by demonstrating the greatly reduced end-to-end service latency using the proposed dynamic adaptation technique over the existing methods. We next investigate the impact of image adaptation techniques under overloaded server conditions. While the proposed dynamic adaptation technique can provide server performance improvement (8/spl times/ lower maximum server latency and 6/spl times/ server capacity increase), even more significant server performance increases can be achieved through the use of a novel configurable hardware/software (HW/SW) architecture for the image adaptation technique. The proposed HW/SW architecture is capable of achieving significantly higher server performance (server capacity increase of 18/spl times/ and server latency decrease of 34/spl times/), while accommodating several different types of image adaptation techniques. Experimental results show that customized image-based data services can be enabled at significantly reduced server costs, and thereby reducing overall wireless service cost.