  To quantify degree of spatial inhomogeneity for multiphase materials we adapt
the entropic descriptor (ED) of a pillar model developed to greyscale images.
To uncover the contribution of each phase we introduce the suitable 'phase
splitting' of the adapted descriptor. As a result, each of the phase
descriptors (PDs) describes the spatial inhomogeneity attributed to each
phase-component. Obviously, their sum equals to the value of the overall
spatial inhomogeneity. We apply this approach to three-phase synthetic
patterns. The black and grey components are aggregated or clustered while the
white phase is the background one. The examples show how the valuable
microstuctural information related separately to each of the phases can be
obtained at any integer length scale. Even dissimilar hidden statistical
periodicities can be easily detected for chosen phases built-up of compact
regular clusters.
