Multi-scale opening – A new morphological operator

Abstract

Theoretical properties of multi-scale opening (MSO), a new mathematical morphological operator, are established and its application to separation of conjoined fuzzy objects is presented. The new MSO operator accounts for distinct intensity properties of individual objects inside the assembly of two conjoined fuzzy objects by combining fuzzy distance transform (FDT), a morphologic feature, with fuzzy connectivity, a topologic feature, to iteratively open two objects starting at large scales and progressing toward finer scales. Results of application of the new mathematical morphological operator to separate conjoined arterial structures in mathematically generated phantoms and for segmentation of arteries and veins in a physical cast phantom of a pig lung are presented. Performance of the MSO operator is also evaluated in terms of patients’ pulmonary non-contrast CT data for separating arteries and veins and for complete carotid vascular segmentation for patient’s CTA data set.