Design and modeling of the generally adopted progressive image transmission regulator and its application

Progressive image transmission (PIT) has been widely developed to serve many applications, such as remote browsing of image database over relatively low bit-rate channels. Generally, a progressive image transmission consists of multiple stages, including an initial stage to send a low-resolution version of the image. The resolution is then improved gradually during the remaining subsequent stages. While the network bandwidth should be competed for among the increasing traffic sources, such a layer structure of resolution motivates our dynamic adaptation of PIT-stage-numbers and transmission rates for image transmissions to alleviate the traffic clusters in low bit-rate channels, which in turn incurs network congestion and data loss problems. We propose a generally adopted PIT regulator, called GAPIT-R, which can be achieved through the adaptation of the PIT-stage-number dependent of the current channel capacity indicated from the TCP flow control mechanisms. In essence, GAPIT-R acts as a traffic shaper/regulator to prevent low bit-rate channels from been congested by the exhaustive transmission of images from senders. With GAPIT-R provided in existing and coming promising progressive image transmission techniques, the first coarse progressive-image can be sent efficiently to the receiver for recognition, and the remaining progressive-images can be transmitted in adaptive rates to prevent the network from been congested.