A video coding system that codes video objects as scalable video object
layers. Data of each video object may be segregated into one or more
layers. A base layer contains sufficient information to decode a basic
representation of the video object. Enhancement layers contain
supplementary data regarding the video object that, if decoded, enhance
the basic representation obtained from the base layer. The present
invention thus provides a coding scheme suitable for use with decoders of
varying processing power. A single decoder may decode only the base layer
of video objects to obtain the basic representation. However, more
powerful decoders may decode the base layer data of video objects and
additional enhancement layer data to obtain improved decoded output. The
coding scheme supports enhancement of both the spatial resolution and the
temporal resolution of video objects.