Biomedical Engineering Reference
In-Depth Information
Figure 11.22:
Level lines and graph of the segmentation function in time step
100 (top row). Then we show graphs of segmentation function after 300 and 800
steps (middle row). In the bottom row we plot the segmented Kanizsa triangle
(color slide).
The next examples are related to medical image segmentation. First we pro-
cess a 2D echocardiography (165
×
175 pixels) with high level of noise and gaps
in ventricular and atrium boundaries (see Fig. 11.23).
In Fig. 11.24 we present segmentation of the left atrium. We start with peak-
like segmentation function,
v
=
1, and we use
ε
=
10
−
2
,
K
=
0
.
1,
τ
=
0
.
001,
TOL
=
10
−
3
, and
δ
=
10
−
5
. In the top row of the figure we present the result of
segmentation with no presmoothing of the given echocardiography. In such a
case 68 time steps, with overall CPU time of 6.54 sec, were needed for threshold
δ
.
