Nonperiodic modes in two-dimensional (2-D) recursive digital filters under finite wordlength effects

Two-dimensional recursive digital filters under finite wordlength and zero input are shown to exhibit unstable responses, which do not satisfy the classical definitions for two-dimensional periodicity. This is in contrast to the one-dimensional case, where instabilities caused by finite-wordlength effects are always periodic for a finite-order filter. The consequences for multidimensional stability tests are mentioned.<
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