  Eliminating two trivial degrees of freedom corresponding to the lowpass DC
response and the highpass Nyquist response in a two-channel multirate filter
bank seems simple enough. Nonetheless, the ISO/IEC JPEG 2000 image coding
standard manages to make this mundane task look totally mysterious. We reveal
the true meaning behind JPEG 2000's arcane specifications for filter bank
normalization and point out how the seemingly trivial matter of gain scaling
leads to highly nontrivial issues concerning uniqueness of lifting
factorizations.
