SPIHT Coding
Runs in passes - one for each bit plane.
Encoder maintains two data structures.
- S, a list of indices (i,j) such that B[i,j] is declared significant in the current bit plane.
- Z, a stack of zero trees of two types.
- rootless (R)
- root-and-childless (RC)
- The nodes in a zero tree are insignificant in the current bit plane. (ignore root in R and root and children in RC)