i
i
i
i
i
i
i
i
70 4 Progressive Fine Granularity Scalable (PFGS) Coding
the properties of FGS, such as fine granularity scalability, channel adaptation, and
error recovery.
There are still several issues to be addressed in the basic PFGS framework pro-
posed by Li et al. [51]. First, it needs multiple extra picture buffers to save multiple
reconstructed layers as references, which increases the memory cost and computa-
tional complexity of the PFGS encoder and decoder. Fortunately, not every reference
layer makes the same contribution to the improvement of coding efficiency. Only a
few among the reference layers make significant contributions to improving coding
efficiency, while others have little effect. How to choose a minimal number of ref-
erence layers