Image Processing Reference

In-Depth Information

FIGURE 3
Edge extraction and mass location results (1024 × 1024 pixels).

2.3.3 Mass location parameter

For a further work, we obtain the mass position coordinate by defining a circle, whose center

corresponds to the center of extracted mass egde, and the radius of which is a middle value of

the distance from boundary pixel to the center position, indicating as: (
cx
,
cy
) and
r
. For
Figure

3
,
the parameter is: (682, 586),
r
= 46. The parametric circle could be used as the initial contour

of deformable model followed by.

2.4 Mass Segmentation

The results of mass location are rough and exist certain gap with the actual boundary, we util-

ize the Snake model to perform an accurate segmentation further.

2.4.1 Typical VFC Snake model

The Snake model defined a parametric curve guided by external forces and internal forces that

pull it toward the edge of ROI until the energy function achieves the minimum. The curve
v
(
s
)

and the minimizing energy function
E
(
v
) forms are

(8)

(9)

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