Unequal importance image communication over heterogeneous networks

An unequal importance communication approach, for cheap, reliable and real-time image communication over heterogeneous networks and its applications in mobile multimedia communication systems is presented. Here, an image is partitioned into different layers of importance: base layer and enhancement layers. The low-rate base layer description, which can be strongly protected, is transmitted through a low-bandwidth, but robust and more expensive channel, supporting delay-sensitive applications (e.g. GSM network), while the high-rate enhancement layer description(s) are transmitted through a high-bandwidth, but high/variable-delay and cheap channel which does not support delay-sensitive applications (e.g. WLAN). In the receiver, when the base layer description is quickly received, an acceptable quality image is reconstructed, and when the enhancement layer description(s) are received a high quality image can be reconstructed. Our practical results indicated that this effective, flexible, and highly compatible method not only facilitates high quality image distribution among heterogeneous networks and increases the coverage, quality of service, and bandwidth and power efficiency but also decreases the delay and cost of image distribution in mobile communication systems.