The embedded zerotree wavelet algorithm (EZW)
is a simple, yet remarkable effective, image compression algorithm, having
the property that the bits in the bit stream are generated
in order of importance, yielding a fully embedded
code. Using an embedded coding algorithm, an encoder can terminate
the encoding at any point thereby allowing a target rate or target
distortion metric to be met exactly. Also, given a bit stream,
the decoder can cease decoding at any point in the bit stream
and still produce exactly the same image that would have been encoded
at the bit rate corresponding to the truncated stream. In addition
to producing a fully embedded bit stream, EZW consistently
produces compression results that are competitive with virtually
all known compression algorithms. (See Figures
and
)