Abstract : The automated segmentation and classification of galaxies still constitute open problems for astronomical imaging, mainly due to their fuzzy and versatile nature, as well as to the multitude of the available channels. In this paper, a mathematical morphology based approach is explored. First, a semi-automated method for multispectral galaxy segmentation, based on the marker controlled watershed transformation is proposed. Moreover, a novel and viewpoint independent morphological feature, based on the top-hat operator, is introduced for the distinction of spiral from elliptical galaxies. Illustrative application examples of the presented approach on actual images are also provided.