<s>
In	O
the	O
field	O
of	O
gesture	B-General_Concept
recognition	I-General_Concept
and	O
image	B-Algorithm
processing	I-Algorithm
,	O
finger	B-Algorithm
tracking	I-Algorithm
is	O
a	O
high-resolution	B-Algorithm
technique	O
developed	O
in	O
1969	O
that	O
is	O
employed	O
to	O
know	O
the	O
consecutive	O
position	O
of	O
the	O
fingers	O
of	O
the	O
user	O
and	O
hence	O
represent	O
objects	O
in	O
3D	O
.	O
</s>
<s>
In	O
addition	O
to	O
that	O
,	O
the	O
finger	B-Algorithm
tracking	I-Algorithm
technique	O
is	O
used	O
as	O
a	O
tool	O
of	O
the	O
computer	O
,	O
acting	O
as	O
an	O
external	B-Device
device	I-Device
in	O
our	O
computer	O
,	O
similar	O
to	O
a	O
keyboard	B-Device
and	O
a	O
mouse	B-Device
.	O
</s>
<s>
The	O
finger	B-Algorithm
tracking	I-Algorithm
system	O
is	O
focused	O
on	O
user-data	O
interaction	O
,	O
where	O
the	O
user	O
interacts	O
with	O
virtual	O
data	O
,	O
by	O
handling	O
through	O
the	O
fingers	O
the	O
volumetric	O
of	O
a	O
3D	O
object	O
that	O
we	O
want	O
to	O
represent	O
.	O
</s>
<s>
Finger	B-Algorithm
tracking	I-Algorithm
systems	O
have	O
been	O
created	O
.	O
</s>
<s>
There	O
are	O
many	O
options	O
for	O
the	O
implementation	O
of	O
finger	B-Algorithm
tracking	I-Algorithm
,	O
principally	O
those	O
used	O
with	O
or	O
without	O
an	O
interface	B-Application
.	O
</s>
<s>
This	O
system	O
mostly	O
uses	O
inertial	O
and	O
optical	O
motion	B-Application
capture	I-Application
systems	O
.	O
</s>
<s>
Inertial	O
motion	B-Application
capture	I-Application
systems	O
are	O
able	O
to	O
capture	O
finger	O
motion	O
by	O
reading	O
the	O
rotation	O
of	O
each	O
finger	O
segment	O
in	O
3D	O
space	O
.	O
</s>
<s>
Applying	O
these	O
rotations	O
to	O
kinematic	B-Application
chain	I-Application
,	O
the	O
whole	O
human	O
hand	O
can	O
be	O
tracked	O
in	O
real	O
time	O
,	O
without	O
occlusion	O
and	O
wireless	O
.	O
</s>
<s>
Hand	O
inertial	O
motion	B-Application
capture	I-Application
systems	O
,	O
like	O
for	O
example	O
Synertial	O
mocap	B-Application
gloves	O
,	O
use	O
tiny	O
IMU	O
based	O
sensors	O
,	O
located	O
on	O
each	O
finger	O
segment	O
.	O
</s>
<s>
There	O
are	O
also	O
mocap	B-Application
glove	O
models	O
with	O
less	O
sensors	O
(	O
13	O
/	O
7	O
sensors	O
)	O
for	O
which	O
the	O
rest	O
of	O
the	O
finger	O
segments	O
is	O
interpolated	O
(	O
proximal	O
segments	O
)	O
or	O
extrapolated	O
(	O
distal	O
segments	O
)	O
.	O
</s>
<s>
On	O
the	O
top	O
of	O
finger	B-Algorithm
tracking	I-Algorithm
,	O
many	O
users	O
require	O
positional	B-Operating_System
tracking	I-Operating_System
for	O
the	O
whole	O
hand	O
in	O
space	O
.	O
</s>
<s>
Capturing	O
the	O
whole	O
body	O
using	O
inertial	O
mocap	B-Application
system	O
(	O
hand	O
skeleton	O
is	O
attached	O
at	O
the	O
end	O
of	O
body	O
skeleton	O
kinematic	B-Application
chain	I-Application
)	O
.	O
</s>
<s>
Capturing	O
position	O
of	O
the	O
palm	O
(	O
forearm	O
)	O
using	O
optical	O
mocap	B-Application
system	O
.	O
</s>
<s>
Capturing	O
position	O
of	O
the	O
palm	O
(	O
forearm	O
)	O
using	O
other	O
position	B-Operating_System
tracking	I-Operating_System
method	O
,	O
widely	O
used	O
in	O
VR	O
headsets	O
(	O
for	O
example	O
HTC	O
Vive	O
Lighthouse	O
)	O
.	O
</s>
<s>
Inertial	O
sensors	O
have	O
two	O
main	O
disadvantages	O
connected	O
with	O
finger	B-Algorithm
tracking	I-Algorithm
:	O
</s>
<s>
Current	O
generations	O
of	O
motion	B-Application
capture	I-Application
gloves	O
are	O
able	O
to	O
withstand	O
magnetic	O
interference	O
.	O
</s>
<s>
The	O
degree	O
to	O
which	O
they	O
are	O
immune	O
to	O
magnetic	O
interference	O
depends	O
on	O
manufacturer	O
,	O
price	O
range	O
and	O
number	O
of	O
sensors	O
used	O
in	O
the	O
mocap	B-Application
glove	O
.	O
</s>
<s>
Three	O
high-resolution	B-Algorithm
cameras	O
are	O
responsible	O
for	O
capturing	O
each	O
marker	O
and	O
measure	O
its	O
positions	O
.	O
</s>
<s>
The	O
visual	O
markers	O
,	O
usually	O
known	O
as	O
rings	O
or	O
bracelets	O
,	O
are	O
used	O
to	O
recognize	B-General_Concept
user	I-General_Concept
gesture	I-General_Concept
in	I-General_Concept
3D	I-General_Concept
.	O
</s>
<s>
In	O
addition	O
,	O
as	O
the	O
classification	O
indicates	O
,	O
these	O
rings	O
act	O
as	O
an	O
interface	B-Application
in	O
2D	O
.	O
</s>
<s>
The	O
interfaces	B-Application
provide	O
more	O
natural	O
3D	B-General_Concept
interaction	I-General_Concept
techniques	O
over	O
base	O
6	O
.	O
</s>
<s>
To	O
detect	O
such	O
pointers	O
through	O
an	O
interaction	O
,	O
we	O
enable	O
ultrasound	B-Application
infrared	O
sensors	O
.	O
</s>
<s>
Because	O
of	O
marker	O
occlusion	O
during	O
capture	O
,	O
tracking	O
fingers	O
is	O
the	O
most	O
challenging	O
part	O
for	O
optical	O
motion	B-Application
capture	I-Application
systems	O
(	O
like	O
Vicon	O
,	O
Optitrack	O
,	O
ART	O
,	O
..	O
)	O
.	O
</s>
<s>
Users	O
of	O
optical	O
mocap	B-Application
systems	O
claims	O
that	O
the	O
most	O
post-process	O
work	O
is	O
usually	O
due	O
to	O
finger	O
capture	O
.	O
</s>
<s>
As	O
the	O
inertial	O
mocap	B-Application
systems	O
(	O
if	O
properly	O
calibrated	O
)	O
are	O
mostly	O
without	O
the	O
need	O
for	O
post-process	O
,	O
the	O
typical	O
use	O
for	O
high	O
end	O
mocap	B-Application
users	O
is	O
to	O
fuse	O
data	O
from	O
inertial	O
mocap	B-Application
systems	O
(	O
fingers	O
)	O
with	O
optical	O
mocap	B-Application
systems	O
(	O
body	O
+	O
position	O
in	O
space	O
)	O
.	O
</s>
<s>
The	O
process	O
of	O
fusing	O
mocap	B-Application
data	O
is	O
based	O
on	O
matching	O
time	O
codes	O
of	O
each	O
frame	O
for	O
inertial	O
and	O
optical	O
mocap	B-Application
system	O
data	O
source	O
.	O
</s>
<s>
This	O
way	O
any	O
3rd	O
party	O
software	O
(	O
for	O
example	O
MotionBuilder	O
,	O
Blender	O
)	O
can	O
apply	O
motions	O
from	O
two	O
sources	O
,	O
independently	O
of	O
the	O
mocap	B-Application
method	O
used	O
.	O
</s>
<s>
Stretch	O
sensor	O
enabled	O
motion	B-Application
capture	I-Application
systems	O
use	O
flexible	O
parallel	O
plate	O
capacitors	O
to	O
detect	O
differences	O
in	O
capacitance	O
when	O
the	O
sensors	O
stretch	O
,	O
bend	O
,	O
shear	O
or	O
are	O
subjected	O
to	O
pressure	O
.	O
</s>
<s>
The	O
robust	O
and	O
flexible	O
qualities	O
of	O
these	O
sensors	O
leads	O
to	O
high	O
fidelity	O
finger	B-Algorithm
tracking	I-Algorithm
and	O
feature	O
in	O
mocap	B-Application
gloves	O
produced	O
by	O
StretchSense	O
.	O
</s>
<s>
Articulated	O
hand	B-Algorithm
tracking	I-Algorithm
is	O
simpler	O
and	O
less	O
expensive	O
than	O
many	O
methods	O
because	O
it	O
only	O
needs	O
one	O
camera	O
.	O
</s>
<s>
We	O
do	O
the	O
axes	O
at	O
each	O
joint	O
and	O
bisector	B-Protocol
of	O
this	O
axis	O
is	O
the	O
projection	O
of	O
the	O
joint	O
.	O
</s>
<s>
Region	O
extraction	O
:	O
left	O
and	O
right	O
hand	B-Algorithm
detection	I-Algorithm
based	O
on	O
a	O
comparison	O
between	O
them	O
.	O
</s>
<s>
Point	O
and	O
pinch	O
gesture	B-General_Concept
recognition	I-General_Concept
:	O
taking	O
into	O
account	O
the	O
points	O
of	O
reference	O
that	O
are	O
visible	O
(	O
fingertips	O
)	O
a	O
certain	O
gesture	O
is	O
associated	O
.	O
</s>
<s>
Pose	B-General_Concept
estimation	I-General_Concept
:	O
a	O
procedure	O
which	O
consists	O
on	O
identify	O
the	O
position	O
of	O
the	O
hands	O
through	O
the	O
use	O
of	O
algorithms	O
that	O
compute	O
the	O
distances	O
between	O
positions	O
.	O
</s>
<s>
The	O
Smart	O
Laser	O
Scanner	O
is	O
a	O
marker-less	O
finger	B-Algorithm
tracking	I-Algorithm
system	O
using	O
a	O
modified	O
laser	O
scanner/projector	O
developed	O
at	O
the	O
University	O
of	O
Tokyo	O
in	O
2003-2004	O
.	O
</s>
<s>
It	O
is	O
capable	O
of	O
acquiring	O
three-dimensional	O
coordinates	O
in	O
real	O
time	O
without	O
the	O
need	O
of	O
any	O
image	B-Algorithm
processing	I-Algorithm
at	O
all	O
(	O
essentially	O
,	O
it	O
is	O
a	O
rangefinder	O
scanner	O
that	O
instead	O
of	O
continuously	O
scanning	O
over	O
the	O
full	O
field	O
of	O
view	O
,	O
restricts	O
its	O
scanning	O
area	O
to	O
a	O
very	O
narrow	O
window	O
precisely	O
the	O
size	O
of	O
the	O
target	O
)	O
.	O
</s>
<s>
Gesture	B-General_Concept
recognition	I-General_Concept
has	O
been	O
demonstrated	O
with	O
this	O
system	O
.	O
</s>
<s>
Definitely	O
,	O
the	O
finger	B-Algorithm
tracking	I-Algorithm
systems	O
are	O
used	O
to	O
represent	O
a	O
virtual	B-Application
reality	I-Application
.	O
</s>
<s>
possibility	O
to	O
operate	O
through	O
natural	O
language	O
or	O
gesture	B-General_Concept
interaction	I-General_Concept
.	O
</s>
