NETCICATS: Network-Conscious Image Compression and Transmission System

NETCICATS is a software system for empirically evaluating network-conscious image compression, an approach that does not simply optimize compression, but which optimizes overall performance when compressed images are transmitted over a lossy packet-switched network such as the Internet. Based on Application Level Framing, an image is compressed into path-MTU-size Application Data Units (ADUs) at the application layer. Each ADU contains enough information to be processed independently of all other ADUs. Each ADU can be delivered to the receiving application out-of-order, thereby enabling faster progressive display of images. NETCICATS allows the empirical investigation of the combination of transport protocol features and compression algorithms that perform best over a lossy packet-switched network. It includes software components from the network layer (e.g., lossy router), transport layer (e.g., innovative transport protocols), and application layer (e.g., compression algorithms, browsers, etc.). We describe each component of the system and explain how the whole system is used. This paper also presents two network-conscious image compression algorithms: networkconscious GIF and wavelet zerotree encoding.