> Wouldn't the 3 shears method take a preposterous¹ amount of memory if you rotate by something like 180 degrees? The first shear will take a w.h image and outp

> Wouldn't the 3 shears method take a preposterous¹ amount of memory if you rotate by something like 180 degrees? The first shear will take a w.h image and output a w.h.h one! If implemented as a three pass algorithm, yes. If implemented as a one pass algorithm, no.