Transcoding of JPEG images for wireless proxy communications

The explosive growth of the Internet and handheld wireless devices is widening a large gap between mobile clients. Mobile clients vary in their hardware and software resources such as screen size, color depth, effective bandwidth, processing power, and the ability to handle different data formats. This makes it difficult for servers to support a wide range of client variations. Application-level adaptation is required to provide a meaningful Internet experience across the range of client capabilities.In this research we introduce an image transcoding proxy server placed between the generic WWW servers and the heterogeneous mobile hosts. The main function of this proxy is to reprocess, on the fly, the most common image formats used on the web for quick transmission of reasonable quality. The transcoding proxy uses the mobile device characteristics as input parameters and can adapt to dynamically changing bandwidth on the proxy-client link. The policy decisions are used to select the most appropriate operations in order to achieve the smallest file size and acceptable image quality. Moreover, our proxy can perform on-demand specific image compression operations, tailoring content to the specific constraints of the user.