<s>
Pfinder	B-Application
is	O
a	O
computer	B-Application
vision	I-Application
system	O
which	O
detects	O
features	O
in	O
video	O
images	O
in	O
order	O
to	O
recognize	O
human	O
figures	O
and	O
their	O
movements	O
and	O
gestures	O
.	O
</s>
<s>
Pfinder	B-Application
was	O
designed	O
by	O
Wren	O
,	O
et	O
al	O
.	O
</s>
<s>
As	O
described	O
by	O
its	O
authors	O
,	O
Pfinder	B-Application
is	O
a	O
"	O
real-time	O
system	O
for	O
tracking	O
people	O
and	O
interpreting	O
their	O
behavior	O
"	O
.	O
</s>
<s>
As	O
an	O
example	O
,	O
Pfinder	B-Application
can	O
track	O
a	O
person	O
's	O
head	O
and	O
hands	O
,	O
and	O
can	O
determine	O
the	O
pose	O
of	O
the	O
body	O
and	O
recognize	B-General_Concept
gestures	I-General_Concept
.	O
</s>
<s>
Pfinder	B-Application
does	O
not	O
cope	O
with	O
multi-modal	O
backgrounds	O
,	O
in	O
which	O
a	O
histogram	O
of	O
the	O
pixel	O
intensity	O
contains	O
more	O
than	O
one	O
distinct	O
peak	O
.	O
</s>
<s>
Pfinder	B-Application
is	O
not	O
able	O
to	O
handle	O
multiple	O
people	O
in	O
the	O
same	O
image	O
well	O
.	O
</s>
