<s>
Discrete	B-Algorithm
Skeleton	I-Algorithm
Evolution	I-Algorithm
(	O
DSE	B-Algorithm
)	O
describes	O
an	O
iterative	O
approach	O
to	O
reducing	O
a	O
morphological	B-Algorithm
or	O
topological	B-Algorithm
skeleton	I-Algorithm
.	O
</s>
<s>
It	O
is	O
a	O
form	O
of	O
pruning	B-Algorithm
in	O
that	O
it	O
removes	O
noisy	O
or	O
redundant	O
branches	O
(	O
spurs	O
)	O
generated	O
by	O
the	O
skeletonization	O
process	O
,	O
while	O
preserving	O
information-rich	O
"	O
trunk	O
"	O
segments	O
.	O
</s>
<s>
DSE	B-Algorithm
algorithms	O
are	O
distinguished	O
by	O
complex	O
,	O
recursive	O
decision-making	O
processes	O
with	O
high	O
computational	O
requirements	O
.	O
</s>
<s>
Pruning	B-Algorithm
methods	O
such	O
as	O
by	O
structuring	O
element	O
(	O
SE	O
)	O
convolution	O
and	O
the	O
Hough	B-Algorithm
transform	I-Algorithm
are	O
general	O
purpose	O
algorithms	O
which	O
quickly	O
pass	O
through	O
an	O
image	O
and	O
eliminate	O
all	O
branches	O
shorter	O
than	O
a	O
given	O
threshold	O
.	O
</s>
<s>
DSE	B-Algorithm
methods	O
are	O
most	O
applicable	O
when	O
detail	O
retention	O
and	O
contour	O
reconstruction	O
are	O
valued	O
.	O
</s>
<s>
Input	O
images	O
will	O
typical	O
contain	O
more	O
data	O
than	O
is	O
necessary	O
to	O
generate	O
an	O
initial	O
skeleton	O
,	O
and	O
thus	O
must	O
be	O
reduced	B-General_Concept
in	O
some	O
way	O
.	O
</s>
<s>
Reducing	O
the	O
resolution	O
,	O
converting	O
to	O
grayscale	O
,	O
and	O
then	O
binary	O
by	O
masking	O
or	O
thresholding	B-Algorithm
are	O
common	O
first	O
steps	O
.	O
</s>
<s>
Morphological	B-Algorithm
operations	O
such	O
as	O
closing	B-Algorithm
,	O
opening	B-Algorithm
,	O
and	O
smoothing	O
of	O
the	O
binary	O
image	O
may	O
also	O
be	O
part	O
of	O
pre-processing	O
.	O
</s>
<s>
DSE	B-Algorithm
techniques	O
may	O
be	O
applied	O
to	O
an	O
existing	O
skeleton	O
or	O
incorporated	O
as	O
part	O
of	O
the	O
skeleton	O
growing	O
algorithm	O
.	O
</s>
<s>
DSE	B-Algorithm
and	O
related	O
methods	O
remove	O
entire	O
spurious	O
branches	O
while	O
leaving	O
the	O
main	O
trunk	O
intact	O
.	O
</s>
