Morphological operations by locally variable structuring elements and their applications to region extraction in ultrasound images

Abstract

SUMMARYIn this paper, we define a new adaptive morphological operation, in which the value of a structuring element varies adaptively depending on the local intensity information of the processing image of interest. We prove that the proposed adaptive morphological operation has almost the same mathematical structure and properties as the conventional ones have. There are many useful functions in the method. Among them are the opening and closing, which implement both smoothing of the image and emphasizing of the edges at a time. Conventional opening operation has a smoothing function but not both. Applying our method to relatively unclear images such as ultrasound ones with speckle noise, its usefulness can be found in extracting regions. We also discuss parameter setting, and its enhancement effect together with experimental results is demonstrated.

Control of variable structure elements in adaptive mathematical morphology for boundary enhancement of ultrasound images

“…The results of boundary enhancement by the proposed method are now compared to the results of the method with a fixed structuring element, the method using a locally variable structuring element (LVSE), which was previously proposed by the authors [10], and other methods based on adaptive morphology. As the objects of comparison, smoothing by NCP and NOP [5], as well as by PUF [7], are considered.…”

“…In the local variable structuring element which was previously proposed by the authors [10], g depends on f and the value is governed only by the intensity information in the local area that can be covered by G. The variable structuring element g proposed in this study incorporates not only the above information, but also other information. g can be determined independently of f.…”

“…The authors have proposed the "locally variable structuring element" (LVSE) [8][9][10], which is determined from the local intensity information of the image to be processed, with a value varying depending on the spatial position. This element has a boundary enhancement function which has not been observed in conventional morphology.…”

Quantitative evaluation of diagnostic information around the contours in ultrasound images

“…This was followed by regional segmentation and estimation of the contour of the 139 designed to adapt the contour to the local features of the image. [20][21][22] As stated above, border extraction is, in principle, image segmentation, and it uses statistical values for quantitative evaluation of peripheral information. For this reason, the present study used statistical methods for extraction and evaluation of borders.…”

“…These smoothing and border-emphasizing processes apply a morphological operation involving local variable structural elements whose values vary depending on local features of the image. [20][21][22] Closing and opening operations with these variable structural elements are known to be capable of emphasizing the border and smoothing the image simultaneously. 21 abnormal tissue.…”