🚀 go-pugleaf

>>>Is there a recipe for generating the "complement" of a given filter?  Or
>>>for generating a pair of filters which are complementary in this sense? 
> 
>>Generate one of the too signals, e.g. the low passed signal.  Subtract it
>>from the original signal to get the high passed signal.
> 
> This is a nice idea, but it won't work in general.
> i.e. simple subtraction doesn't consider the phase response of H(z).
> Something must have been written on this, what about Quadrature Mirror
> Filterbanks ??

You could try this one: Tree-Structured Complementary Filter Banks
Using All-Pass Sections, Regalia P, Mitra S, Vaidyanathan P, Renfors
M, Neuvo Y. IEEE Transactions on Circuits and Systems, Vol. CAS-34,
No. 12, Dec. 1987.