Morphological segmentation and classification of marble textures at macroscopical scale

This paper presents a methodology mainly based on mathematical morphology to segment and classify colour images of polished samples of marbles at the macroscopic scale. The distinct textural regions are segmented through a watershed-based procedure, and the over-segmentation problem is surpassed with the merging of adjacent regions according to criteria based on the analysis of alternative gradients obtained in grey and colour images. The classification of the elementary textural units in three classes (vein, background and transition) is performed with a morphological partitioning method of feature space. The evaluation and analyses of the methodology and alternatives presented are performed on a set of polished Portuguese marbles.