Biomedical Engineering Reference
In-Depth Information
Figure 5.
Illustration of segmentation of cellular structure in an EM photomicrograph.
Reprinted with permission from [16]. Copyright c
1994, IEEE.
(a)
(b)
(c)
(d)
Figure 6.
Illustration of snake-growing algorithm in comparison to conventional snake. (a)
Initial contour shown in white dots. (b) Result of conventional snake. (c-e) Performance of
snake-growing algorithm. Reprinted with permission from [18]. Copyright c
1990, IEEE.
Leymarie and Levine [19] utilized a distance transformmetric from the gradi-
ent informationwithin the active contour framework to define a
grassfire transform
.
The main motivation of the work was to define shape through skeletonization. In
particular, an object's boundary is taken as the initial firefront that propagates
within the interior of the object defined by the closed boundaries of the object.
Points where the firefronts meet are considered the skeleton points of the rep-
resentative object. The firefront propagation is accomplished using the active
contour framework guiding the propagation using the distance transform from the
boundaries. This work tries to bring in the gradient-based and regional informa-
