Investigation Of Threshold Dependence In Adaptive Vector Quantization For Image Transmission In Packet Switched Networks
CONSTANTINE N. MANIKOPOULOS, Hao Sun, H. Hsu · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1988
In heavily congested packet-switched networks, instead of trying, a priory, to predict the load to the network for a particular set of users, a preferred approach may be to endeavor to control the load. In order to effect dynamic control of the network load, the user (video encoder), and the service provider (packet-switched network), must be interactively linked, in marked departure of traditional source - network separation. Moreover, the resulting source-network system must be capable to dynamically adjust the values of the average bit rate (B) and/or distortion (D) of the variable bit rate transmission source. Adaptive vector quantization has been employed to encode the image source with constant local picture quality: An activity index, A, has been used to classify image areas into two groups, active and non-active, according to whether A>T or A