On the usability of practical stable n-D systems for signal processing applications

In practice, n-D signal processing problems often show the property that underlying signals are unbounded with respect to only one direction, like the spatio-temporal signal of a line-scan camera, for example. Thus, the use of systems which meet the conditions of practical BIBO stability, mainly known from the field of control theory, seems to be feasible. In this paper the practical BIBO stability concept introduced by Agathoklis and Bruton [1] is analyzed with respect to its applicability in the field of signal processing applications. It is shown that practical stability in its original form is not sufficient in signal processing if not further conditions are supposed. This is done by comparing the 2D Fourier transform of the actually measured impulse response of exemplary systems to the frequency response expected on basis of the transfer function.