In this paper we describe a rotation-invariant multi-scale morphological method for texture analysis. Compared with existing methods our method has three advantages. First, it can be implemented efficiently. Furthermore, our method can be used for the computation of size and strict shape attributes, which we use for the computation of 2-D size-shape pattern spectra. Finally, our method is rotation-invariant. Although the latter can also be approximated by morphological methods by using structuring elements at different angles, this tends to be computationally intensive.