<s>
Visualization	B-Application
or	O
visualisation	B-Application
(	O
see	O
spelling	O
differences	O
)	O
is	O
any	O
technique	O
for	O
creating	O
images	O
,	O
diagrams	O
,	O
or	O
animations	O
to	O
communicate	O
a	O
message	O
.	O
</s>
<s>
Visualization	B-Application
through	O
visual	O
imagery	O
has	O
been	O
an	O
effective	O
way	O
to	O
communicate	O
both	O
abstract	O
and	O
concrete	O
ideas	O
since	O
the	O
dawn	O
of	O
humanity	O
.	O
</s>
<s>
Examples	O
from	O
history	O
include	O
cave	O
paintings	O
,	O
Egyptian	O
hieroglyphs	O
,	O
Greek	O
geometry	O
,	O
and	O
Leonardo	B-Application
da	I-Application
Vinci	I-Application
's	O
revolutionary	O
methods	O
of	O
technical	B-Application
drawing	I-Application
for	O
engineering	O
and	O
scientific	O
purposes	O
.	O
</s>
<s>
Visualization	B-Application
today	O
has	O
ever-expanding	O
applications	O
in	O
science	O
,	O
education	O
,	O
engineering	O
(	O
e.g.	O
,	O
product	O
visualization	B-Application
)	O
,	O
interactive	B-General_Concept
multimedia	I-General_Concept
,	O
medicine	B-Application
,	O
etc	O
.	O
</s>
<s>
Typical	O
of	O
a	O
visualization	B-Application
application	O
is	O
the	O
field	O
of	O
computer	O
graphics	O
.	O
</s>
<s>
The	O
invention	O
of	O
computer	O
graphics	O
(	O
and	O
3D	O
computer	O
graphics	O
)	O
may	O
be	O
the	O
most	O
important	O
development	O
in	O
visualization	B-Application
since	O
the	O
invention	O
of	O
central	B-Architecture
perspective	I-Architecture
in	O
the	O
Renaissance	B-Application
period	O
.	O
</s>
<s>
The	O
development	O
of	O
animation	O
also	O
helped	O
advance	O
visualization	B-Application
.	O
</s>
<s>
The	O
use	O
of	O
visualization	B-Application
to	O
present	O
information	O
is	O
not	O
a	O
new	O
phenomenon	O
.	O
</s>
<s>
Examples	O
from	O
cartography	O
include	O
Ptolemy	O
's	O
Geographia	O
(	O
2nd	O
century	O
AD	O
)	O
,	O
a	O
map	O
of	O
China	O
(	O
1137	O
AD	O
)	O
,	O
and	O
Minard	O
's	O
map	O
(	O
1861	O
)	O
of	O
Napoleon	B-Device
's	O
invasion	O
of	O
Russia	O
a	O
century	O
and	O
a	O
half	O
ago	O
.	O
</s>
<s>
Most	O
of	O
the	O
concepts	O
learned	O
in	O
devising	O
these	O
images	O
carry	O
over	O
in	O
a	O
straightforward	O
manner	O
to	O
computer	B-Application
visualization	I-Application
.	O
</s>
<s>
The	O
recent	O
emphasis	O
on	O
visualization	B-Application
started	O
in	O
1987	O
with	O
the	O
publication	O
of	O
Visualization	B-Application
in	O
Scientific	O
Computing	O
,	O
a	O
special	O
issue	O
of	O
Computer	O
Graphics	O
.	O
</s>
<s>
Since	O
then	O
,	O
there	O
have	O
been	O
several	O
conferences	O
and	O
workshops	O
,	O
co-sponsored	O
by	O
the	O
IEEE	O
Computer	O
Society	O
and	O
ACM	O
SIGGRAPH	O
,	O
devoted	O
to	O
the	O
general	O
topic	O
,	O
and	O
special	O
areas	O
in	O
the	O
field	O
,	O
for	O
example	O
volume	O
visualization	B-Application
.	O
</s>
<s>
TV	O
also	O
offers	O
scientific	B-Application
visualizations	I-Application
when	O
it	O
shows	O
computer	O
drawn	O
and	O
animated	O
reconstructions	O
of	O
road	O
or	O
airplane	O
accidents	O
.	O
</s>
<s>
Some	O
of	O
the	O
most	O
popular	O
examples	O
of	O
scientific	B-Application
visualizations	I-Application
are	O
computer-generated	O
images	O
that	O
show	O
real	O
spacecraft	O
in	O
action	O
,	O
out	O
in	O
the	O
void	O
far	O
beyond	O
Earth	O
,	O
or	O
on	O
other	O
planets	O
.	O
</s>
<s>
Dynamic	O
forms	O
of	O
visualization	B-Application
,	O
such	O
as	O
educational	O
animation	O
or	O
timelines	B-Application
,	O
have	O
the	O
potential	O
to	O
enhance	O
learning	O
about	O
systems	O
that	O
change	O
over	O
time	O
.	O
</s>
<s>
Apart	O
from	O
the	O
distinction	O
between	O
interactive	B-General_Concept
visualizations	I-General_Concept
and	O
animation	O
,	O
the	O
most	O
useful	O
categorization	O
is	O
probably	O
between	O
abstract	O
and	O
model-based	O
scientific	B-Application
visualizations	I-Application
.	O
</s>
<s>
The	O
abstract	O
visualizations	B-Application
show	O
completely	O
conceptual	O
constructs	O
in	O
2D	O
or	O
3D	O
.	O
</s>
<s>
The	O
model-based	O
visualizations	B-Application
either	O
place	O
overlays	O
of	O
data	O
on	O
real	O
or	O
digitally	O
constructed	O
images	O
of	O
reality	O
or	O
make	O
a	O
digital	O
construction	O
of	O
a	O
real	O
object	B-Algorithm
directly	O
from	O
the	O
scientific	O
data	O
.	O
</s>
<s>
Scientific	B-Application
visualization	I-Application
is	O
usually	O
done	O
with	O
specialized	O
software	O
,	O
though	O
there	O
are	O
a	O
few	O
exceptions	O
,	O
noted	O
below	O
.	O
</s>
<s>
Some	O
of	O
these	O
specialized	O
programs	O
have	O
been	O
released	O
as	O
open	B-Application
source	I-Application
software	I-Application
,	O
having	O
very	O
often	O
its	O
origins	O
in	O
universities	O
,	O
within	O
an	O
academic	O
environment	O
where	O
sharing	O
software	O
tools	O
and	O
giving	O
access	O
to	O
the	O
source	O
code	O
is	O
common	O
.	O
</s>
<s>
There	O
are	O
also	O
many	O
proprietary	B-Application
software	I-Application
packages	O
of	O
scientific	B-Application
visualization	I-Application
tools	O
.	O
</s>
<s>
Models	O
and	O
frameworks	O
for	O
building	O
visualizations	B-Application
include	O
the	O
data	B-Application
flow	I-Application
models	O
popularized	O
by	O
systems	O
such	O
as	O
AVS	O
,	O
IRIS	O
Explorer	O
,	O
and	O
VTK	B-Language
toolkit	O
,	O
and	O
data	O
state	O
models	O
in	O
spreadsheet	O
systems	O
such	O
as	O
the	O
Spreadsheet	O
for	O
Visualization	B-Application
and	O
Spreadsheet	O
for	O
Images	O
.	O
</s>
<s>
As	O
a	O
subject	O
in	O
computer	B-General_Concept
science	I-General_Concept
,	O
scientific	B-Application
visualization	I-Application
is	O
the	O
use	O
of	O
interactive	O
,	O
sensory	O
representations	O
,	O
typically	O
visual	O
,	O
of	O
abstract	O
data	O
to	O
reinforce	O
cognition	O
,	O
hypothesis	O
building	O
,	O
and	O
reasoning	O
.	O
</s>
<s>
Scientific	B-Application
visualization	I-Application
is	O
the	O
transformation	O
,	O
selection	O
,	O
or	O
representation	O
of	O
data	O
from	O
simulations	O
or	O
experiments	O
,	O
with	O
an	O
implicit	O
or	O
explicit	O
geometric	O
structure	O
,	O
to	O
allow	O
the	O
exploration	O
,	O
analysis	O
,	O
and	O
understanding	O
of	O
the	O
data	O
.	O
</s>
<s>
Scientific	B-Application
visualization	I-Application
focuses	O
and	O
emphasizes	O
the	O
representation	O
of	O
higher	O
order	O
data	O
using	O
primarily	O
graphics	O
and	O
animation	O
techniques	O
.	O
</s>
<s>
It	O
is	O
a	O
very	O
important	O
part	O
of	O
visualization	B-Application
and	O
maybe	O
the	O
first	O
one	O
,	O
as	O
the	O
visualization	B-Application
of	O
experiments	O
and	O
phenomena	O
is	O
as	O
old	O
as	O
science	O
itself	O
.	O
</s>
<s>
Traditional	O
areas	O
of	O
scientific	B-Application
visualization	I-Application
are	O
flow	B-Application
visualization	I-Application
,	O
medical	B-Application
visualization	I-Application
,	O
astrophysical	O
visualization	B-Application
,	O
and	O
chemical	O
visualization	B-Application
.	O
</s>
<s>
Data	O
visualization	B-Application
is	O
a	O
related	O
subcategory	O
of	O
visualization	B-Application
dealing	O
with	O
statistical	B-Application
graphics	I-Application
and	O
geospatial	B-General_Concept
data	I-General_Concept
(	O
as	O
in	O
thematic	B-Application
cartography	I-Application
)	O
that	O
is	O
abstracted	O
in	O
schematic	O
form	O
.	O
</s>
<s>
Information	O
visualization	B-Application
concentrates	O
on	O
the	O
use	O
of	O
computer-supported	O
tools	O
to	O
explore	O
large	O
amount	O
of	O
abstract	O
data	O
.	O
</s>
<s>
The	O
term	O
"	O
information	O
visualization	B-Application
"	O
was	O
originally	O
coined	O
by	O
the	O
User	O
Interface	O
Research	O
Group	O
at	O
Xerox	O
PARC	O
and	O
included	O
Jock	O
Mackinlay	O
.	O
</s>
<s>
Practical	O
application	O
of	O
information	O
visualization	B-Application
in	O
computer	O
programs	O
involves	O
selecting	O
,	O
transforming	B-General_Concept
,	O
and	O
representing	O
abstract	O
data	O
in	O
a	O
form	O
that	O
facilitates	O
human	O
interaction	O
for	O
exploration	O
and	O
understanding	O
.	O
</s>
<s>
Important	O
aspects	O
of	O
information	O
visualization	B-Application
are	O
dynamics	O
of	O
visual	B-Application
representation	I-Application
and	O
the	O
interactivity	O
.	O
</s>
<s>
Strong	O
techniques	O
enable	O
the	O
user	O
to	O
modify	O
the	O
visualization	B-Application
in	O
real-time	O
,	O
thus	O
affording	O
unparalleled	O
perception	O
of	O
patterns	O
and	O
structural	O
relations	O
in	O
the	O
abstract	O
data	O
in	O
question	O
.	O
</s>
<s>
Educational	O
visualization	B-Application
is	O
using	O
a	O
simulation	O
to	O
create	O
an	O
image	O
of	O
something	O
so	O
it	O
can	O
be	O
taught	O
about	O
.	O
</s>
<s>
The	O
use	O
of	O
visual	B-Application
representations	I-Application
to	O
transfer	O
knowledge	O
between	O
at	O
least	O
two	O
persons	O
aims	O
to	O
improve	O
the	O
transfer	O
of	O
knowledge	O
by	O
using	O
computer	O
and	O
non-computer-based	O
visualization	B-Application
methods	O
complementarily	O
.	O
</s>
<s>
Thus	O
properly	O
designed	O
visualization	B-Application
is	O
an	O
important	O
part	O
of	O
not	O
only	O
data	O
analysis	O
but	O
knowledge	O
transfer	O
process	O
,	O
too	O
.	O
</s>
<s>
For	O
example	O
,	O
visualization	B-Application
of	O
a	O
3D	O
scalar	O
field	O
may	O
be	O
implemented	O
using	O
iso-surfaces	O
for	O
field	O
distribution	O
and	O
textures	O
for	O
the	O
gradient	O
of	O
the	O
field	O
.	O
</s>
<s>
Examples	O
of	O
such	O
visual	O
formats	O
are	O
sketches	O
,	O
diagrams	O
,	O
images	O
,	O
objects	O
,	O
interactive	B-General_Concept
visualizations	I-General_Concept
,	O
information	O
visualization	B-Application
applications	O
,	O
and	O
imaginary	O
visualizations	B-Application
as	O
in	O
stories	O
.	O
</s>
<s>
While	O
information	O
visualization	B-Application
concentrates	O
on	O
the	O
use	O
of	O
computer-supported	O
tools	O
to	O
derive	O
new	O
insights	O
,	O
knowledge	O
visualization	B-Application
focuses	O
on	O
transferring	O
insights	O
and	O
creating	O
new	O
knowledge	O
in	O
groups	O
.	O
</s>
<s>
Beyond	O
the	O
mere	O
transfer	O
of	O
facts	O
,	O
knowledge	O
visualization	B-Application
aims	O
to	O
further	O
transfer	O
insights	O
,	O
experiences	O
,	O
attitudes	O
,	O
values	O
,	O
expectations	O
,	O
perspectives	O
,	O
opinions	O
,	O
and	O
predictions	O
by	O
using	O
various	O
complementary	O
visualizations	B-Application
.	O
</s>
<s>
involves	O
visualization	B-Application
software	I-Application
technology	O
for	O
the	O
viewing	O
and	O
manipulation	O
of	O
3D	O
models	O
,	O
technical	B-Application
drawing	I-Application
and	O
other	O
related	O
documentation	O
of	O
manufactured	O
components	O
and	O
large	O
assemblies	O
of	O
products	O
.	O
</s>
<s>
Product	O
visualization	B-Application
software	I-Application
typically	O
provides	O
high	O
levels	O
of	O
photorealism	O
so	O
that	O
a	O
product	O
can	O
be	O
viewed	O
before	O
it	O
is	O
actually	O
manufactured	O
.	O
</s>
<s>
Technical	B-Application
visualization	I-Application
is	O
an	O
important	O
aspect	O
of	O
product	O
development	O
.	O
</s>
<s>
Originally	O
technical	B-Application
drawings	I-Application
were	O
made	O
by	O
hand	O
,	O
but	O
with	O
the	O
rise	O
of	O
advanced	O
computer	O
graphics	O
the	O
drawing	O
board	O
has	O
been	O
replaced	O
by	O
computer-aided	B-Application
design	I-Application
(	O
CAD	B-Application
)	O
.	O
</s>
<s>
CAD-drawings	O
and	O
models	O
have	O
several	O
advantages	O
over	O
hand-made	O
drawings	O
such	O
as	O
the	O
possibility	O
of	O
3-D	O
modeling	O
,	O
rapid	B-Device
prototyping	I-Device
,	O
and	O
simulation	O
.	O
</s>
<s>
3D	O
product	O
visualization	B-Application
promises	O
more	O
interactive	O
experiences	O
for	O
online	O
shoppers	O
,	O
but	O
also	O
challenges	O
retailers	O
to	O
overcome	O
hurdles	O
in	O
the	O
production	O
of	O
3D	O
content	O
,	O
as	O
large-scale	O
3D	O
content	O
production	O
can	O
be	O
extremely	O
costly	O
and	O
time-consuming	O
.	O
</s>
<s>
Recent	O
research	O
in	O
the	O
field	O
has	O
focused	O
on	O
web	O
design	O
and	O
graphically	O
oriented	O
usability	B-General_Concept
.	O
</s>
<s>
Visual	B-Application
analytics	I-Application
focuses	O
on	O
human	O
interaction	O
with	O
visualization	B-Application
systems	O
as	O
part	O
of	O
a	O
larger	O
process	O
of	O
data	O
analysis	O
.	O
</s>
<s>
Visual	B-Application
analytics	I-Application
has	O
been	O
defined	O
as	O
"	O
the	O
science	O
of	O
analytical	O
reasoning	O
supported	O
by	O
the	O
interactive	O
visual	O
interface	O
"	O
.	O
</s>
<s>
Visual	B-Application
analytics	I-Application
research	O
concentrates	O
on	O
support	O
for	O
perceptual	O
and	O
cognitive	O
operations	O
that	O
enable	O
users	O
to	O
detect	O
the	O
expected	O
and	O
discover	O
the	O
unexpected	O
in	O
complex	O
information	O
spaces	O
.	O
</s>
<s>
Technologies	O
resulting	O
from	O
visual	B-Application
analytics	I-Application
find	O
their	O
application	O
in	O
almost	O
all	O
fields	O
,	O
but	O
are	O
being	O
driven	O
by	O
critical	O
needs	O
(	O
and	O
funding	O
)	O
in	O
biology	O
and	O
national	O
security	O
.	O
</s>
<s>
Interactive	B-General_Concept
visualization	I-General_Concept
or	O
interactive	O
visualisation	B-Application
is	O
a	O
branch	O
of	O
graphic	B-Application
visualization	I-Application
in	O
computer	B-General_Concept
science	I-General_Concept
that	O
involves	O
studying	O
how	O
humans	O
interact	O
with	O
computers	O
to	O
create	O
graphic	O
illustrations	O
of	O
information	O
and	O
how	O
this	O
process	O
can	O
be	O
made	O
more	O
efficient	O
.	O
</s>
<s>
For	O
a	O
visualization	B-Application
to	O
be	O
considered	O
interactive	O
it	O
must	O
satisfy	O
two	O
criteria	O
:	O
</s>
<s>
Response	O
time	O
:	O
changes	O
made	O
by	O
the	O
human	O
must	O
be	O
incorporated	O
into	O
the	O
visualization	B-Application
in	O
a	O
timely	O
manner	O
.	O
</s>
<s>
In	O
general	O
,	O
interactive	B-General_Concept
visualization	I-General_Concept
is	O
considered	O
a	O
soft	O
real-time	O
task	O
.	O
</s>
<s>
One	O
particular	O
type	O
of	O
interactive	B-General_Concept
visualization	I-General_Concept
is	O
virtual	B-Application
reality	I-Application
(	O
VR	O
)	O
,	O
where	O
the	O
visual	B-Application
representation	I-Application
of	O
information	O
is	O
presented	O
using	O
an	O
immersive	O
display	O
device	O
such	O
as	O
a	O
stereo	O
projector	O
(	O
see	O
stereoscopy	B-Algorithm
)	O
.	O
</s>
<s>
Another	O
type	O
of	O
interactive	B-General_Concept
visualization	I-General_Concept
is	O
collaborative	O
visualization	B-Application
,	O
in	O
which	O
multiple	O
people	O
interact	O
with	O
the	O
same	O
computer	B-Application
visualization	I-Application
to	O
communicate	O
their	O
ideas	O
to	O
each	O
other	O
or	O
to	O
explore	O
information	O
cooperatively	O
.	O
</s>
<s>
Frequently	O
,	O
collaborative	O
visualization	B-Application
is	O
used	O
when	O
people	O
are	O
physically	O
separated	O
.	O
</s>
<s>
Using	O
several	O
networked	O
computers	O
,	O
the	O
same	O
visualization	B-Application
can	O
be	O
presented	O
to	O
each	O
person	O
simultaneously	O
.	O
</s>
<s>
The	O
people	O
then	O
make	O
annotations	O
to	O
the	O
visualization	B-Application
as	O
well	O
as	O
communicate	O
via	O
audio	O
(	O
i.e.	O
,	O
telephone	O
)	O
,	O
video	O
(	O
i.e.	O
,	O
a	O
video-conference	O
)	O
,	O
or	O
text	O
(	O
i.e.	O
,	O
IRC	B-Protocol
)	O
messages	O
.	O
</s>
<s>
The	O
Programmer	B-Library
's	I-Library
Hierarchical	I-Library
Interactive	I-Library
Graphics	I-Library
System	I-Library
(	O
PHIGS	B-Library
)	O
was	O
one	O
of	O
the	O
first	O
programmatic	O
efforts	O
at	O
interactive	B-General_Concept
visualization	I-General_Concept
and	O
provided	O
an	O
enumeration	O
of	O
the	O
types	O
of	O
input	O
humans	O
provide	O
.	O
</s>
<s>
Pick	O
some	O
part	O
of	O
an	O
existing	O
visual	B-Application
representation	I-Application
;	O
</s>
<s>
Input	O
devices	O
range	O
from	O
the	O
common	O
–	O
keyboards	B-Device
,	O
mice	B-Device
,	O
graphics	B-Device
tablets	I-Device
,	O
trackballs	B-Device
,	O
and	O
touchpads	B-Application
–	O
to	O
the	O
esoteric	O
–	O
wired	B-General_Concept
gloves	I-General_Concept
,	O
boom	O
arms	O
,	O
and	O
even	O
omnidirectional	B-General_Concept
treadmills	I-General_Concept
.	O
</s>
<s>
When	O
the	O
information	O
being	O
presented	O
is	O
altered	O
,	O
the	O
visualization	B-Application
is	O
usually	O
part	O
of	O
a	O
feedback	O
loop	O
.	O
</s>
<s>
For	O
example	O
,	O
consider	O
an	O
aircraft	O
avionics	O
system	O
where	O
the	O
pilot	O
inputs	O
roll	O
,	O
pitch	O
,	O
and	O
yaw	O
and	O
the	O
visualization	B-Application
system	O
provides	O
a	O
rendering	O
of	O
the	O
aircraft	O
's	O
new	O
attitude	O
.	O
</s>
<s>
Another	O
example	O
would	O
be	O
a	O
scientist	O
who	O
changes	O
a	O
simulation	O
while	O
it	O
is	O
running	O
in	O
response	O
to	O
a	O
visualization	B-Application
of	O
its	O
current	O
progress	O
.	O
</s>
<s>
Experiments	O
have	O
shown	O
that	O
a	O
delay	O
of	O
more	O
than	O
20	O
ms	O
between	O
when	O
input	O
is	O
provided	O
and	O
a	O
visual	B-Application
representation	I-Application
is	O
updated	O
is	O
noticeable	O
by	O
most	O
people	O
.	O
</s>
<s>
Thus	O
it	O
is	O
desirable	O
for	O
an	O
interactive	B-General_Concept
visualization	I-General_Concept
to	O
provide	O
a	O
rendering	O
based	O
on	O
human	O
input	O
within	O
this	O
time	O
frame	O
.	O
</s>
<s>
However	O
,	O
when	O
large	O
amounts	O
of	O
data	O
must	O
be	O
processed	O
to	O
create	O
a	O
visualization	B-Application
,	O
this	O
becomes	O
hard	O
or	O
even	O
impossible	O
with	O
current	O
technology	O
.	O
</s>
<s>
Thus	O
the	O
term	O
"	O
interactive	B-General_Concept
visualization	I-General_Concept
"	O
is	O
usually	O
applied	O
to	O
systems	O
that	O
provide	O
feedback	O
to	O
users	O
within	O
several	O
seconds	O
of	O
input	O
.	O
</s>
<s>
The	O
term	O
interactive	O
framerate	O
is	O
often	O
used	O
to	O
measure	O
how	O
interactive	O
a	O
visualization	B-Application
is	O
.	O
</s>
<s>
Framerates	O
measure	O
the	O
frequency	O
with	O
which	O
an	O
image	O
(	O
a	O
frame	O
)	O
can	O
be	O
generated	O
by	O
a	O
visualization	B-Application
system	O
.	O
</s>
<s>
Specifically	O
,	O
it	O
is	O
possible	O
to	O
achieve	O
a	O
good	O
framerate	O
of	O
50	O
frame/s	O
but	O
if	O
the	O
images	O
generated	O
refer	O
to	O
changes	O
to	O
the	O
visualization	B-Application
that	O
a	O
person	O
made	O
more	O
than	O
1	O
second	O
ago	O
,	O
it	O
will	O
not	O
feel	O
interactive	O
to	O
a	O
person	O
.	O
</s>
<s>
The	O
rapid	O
response	O
time	O
required	O
for	O
interactive	B-General_Concept
visualization	I-General_Concept
is	O
a	O
difficult	O
constraint	O
to	O
meet	O
and	O
there	O
are	O
several	O
approaches	O
that	O
have	O
been	O
explored	O
to	O
provide	O
people	O
with	O
rapid	O
visual	O
feedback	O
based	O
on	O
their	O
input	O
.	O
</s>
<s>
Parallel	B-Operating_System
rendering	I-Operating_System
–	O
where	O
more	O
than	O
one	O
computer	O
or	O
video	O
card	O
is	O
used	O
simultaneously	O
to	O
render	O
an	O
image	O
.	O
</s>
<s>
Multiple	O
frames	O
can	O
be	O
rendered	O
at	O
the	O
same	O
time	O
by	O
different	O
computers	O
and	O
the	O
results	O
transferred	O
over	O
the	O
network	O
for	O
display	O
on	O
a	O
single	O
monitor	B-Device
.	O
</s>
<s>
Progressive	O
rendering	O
–	O
where	O
a	O
framerate	O
is	O
guaranteed	O
by	O
rendering	O
some	O
subset	O
of	O
the	O
information	O
to	O
be	O
presented	O
and	O
providing	O
incremental	O
(	O
progressive	O
)	O
improvements	O
to	O
the	O
rendering	O
once	O
the	O
visualization	B-Application
is	O
no	O
longer	O
changing	O
.	O
</s>
<s>
Level-of-detail	O
(	O
LOD	O
)	O
rendering	O
–	O
where	O
simplified	O
representations	O
of	O
information	O
are	O
rendered	O
to	O
achieve	O
a	O
desired	O
framerate	O
while	O
a	O
person	O
is	O
providing	O
input	O
and	O
then	O
the	O
full	O
representation	O
is	O
used	O
to	O
generate	O
a	O
still	O
image	O
once	O
the	O
person	O
is	O
through	O
manipulating	O
the	O
visualization	B-Application
.	O
</s>
<s>
When	O
the	O
information	O
being	O
represented	O
is	O
stored	O
in	O
a	O
topologically	B-Architecture
rectangular	O
array	O
(	O
as	O
is	O
common	O
with	O
digital	B-Application
photos	I-Application
,	O
MRI	O
scans	O
,	O
and	O
finite	B-Algorithm
difference	I-Algorithm
simulations	O
)	O
,	O
a	O
lower	O
resolution	O
version	O
can	O
easily	O
be	O
generated	O
by	O
skipping	O
n	O
points	O
for	O
each	O
1	O
point	O
rendered	O
.	O
</s>
<s>
Subsampling	O
can	O
also	O
be	O
used	O
to	O
accelerate	O
rendering	O
techniques	O
such	O
as	O
volume	O
visualization	B-Application
that	O
require	O
more	O
than	O
twice	O
the	O
computations	O
for	O
an	O
image	O
twice	O
the	O
size	O
.	O
</s>
<s>
By	O
rendering	O
a	O
smaller	O
image	O
and	O
then	O
scaling	B-Algorithm
the	O
image	O
to	O
fill	O
the	O
requested	O
screen	O
space	O
,	O
much	O
less	O
time	O
is	O
required	O
to	O
render	O
the	O
same	O
data	O
.	O
</s>
<s>
Frameless	O
rendering	O
–	O
where	O
the	O
visualization	B-Application
is	O
no	O
longer	O
presented	O
as	O
a	O
time	O
series	O
of	O
images	O
,	O
but	O
as	O
a	O
single	O
image	O
where	O
different	O
regions	O
are	O
updated	O
over	O
time	O
.	O
</s>
