Fast Algorithms of Morphological Operations by Double Structuring Elements and Their Application to Ultrasound Image

Abstract

We propose fast algorithms for gray-scale morphology by double structuring elements (DSEs). The fast algorithms are implemented with chain rule and decomposition of the DSEs. The DSE allows morphological openings to sharpen edges of the image components, changing shape of the domain and gray values of the DSE with respect to spatial positions to adapt them for local structure. In application to contrast enhancement of ultrasound image, the proposed method improves the contrast of tissue boundaries without speckle emphasis. The proposed method shows better performance both in sharpening and in computational complexity, compared to the conventional morphological sharpening with spatially invariant domain of the DSE.