| EEcient implementation of morphological operations requires the decomposition of structuring elements into the dilation of smaller structuring elements. Zhuang and Haralick presented a search algorithm to nd optimal decompositions of structuring elements in binary morphology. In this paper we use the concepts of Top of a set and Umbra of a surface to extend this algorithm to nd an optimal dec...

AbstructEfficient implementation of morphological operations requires the decomposition of structuring elements into the dilation of smaller structuring elements. Zhuang and Haralick presented a search algorithm to find optimal decompositions of structuring elements in binary morphology. In this paper, we use the concepts of Top of a set and Umbra of a surface to extend this algorithm to find a...

Shadow detection is useful in many applications like image segmentation, scene interpretation and object recognition/tracking. Shadow in images is formed when direct light from a light source cannot reach due to obstruction by an object. Shadow removal is a critical step for improving object detection and tracking. Many algorithms for shadow detection have been proposed in the literature. This ...

Extending the rigorous presentation of the “classical umbral calculus” [28], the so-called partition polynomials are interpreted with the aim to point out the umbral nature of the Poisson random variables. Among the new umbrae introduced, the main tool is the partition umbra that leads also to a simple expression of the functional composition of the exponential power series. Moreover a new shor...

In the present work a statistical investigation of the spatial distribution of longitudinal coordinates of sunspot data has been carried out. For the analysis the maximal area of umbra plus penumbra of sunspot groups has been taken into account. Spatial distributions of longitudinal coordinates of sunspot data are obtained in diierent coordinate systems (e.g. Carrington, equatorial and diierent...