<s>
An	O
image	B-Application
scanner	I-Application
—	O
often	O
abbreviated	O
to	O
just	O
scanner	O
—	O
is	O
a	O
device	O
that	O
optically	O
scans	O
images	O
,	O
printed	O
text	O
,	O
handwriting	O
or	O
an	O
object	O
and	O
converts	O
it	O
to	O
a	O
digital	B-Algorithm
image	I-Algorithm
.	O
</s>
<s>
Hand-held	O
scanners	O
,	O
where	O
the	O
device	O
is	O
moved	O
by	O
hand	O
,	O
have	O
evolved	O
from	O
text	O
scanning	O
"	O
wands	O
"	O
to	O
3D	B-Algorithm
scanners	I-Algorithm
used	O
for	O
industrial	O
design	O
,	O
reverse	O
engineering	O
,	O
test	O
and	O
measurement	O
,	O
orthotics	O
,	O
gaming	O
and	O
other	O
applications	O
.	O
</s>
<s>
Modern	O
scanners	O
typically	O
use	O
a	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	B-Algorithm
)	O
or	O
a	O
contact	O
image	O
sensor	O
(	O
CIS	O
)	O
as	O
the	O
image	O
sensor	O
,	O
whereas	O
drum	O
scanners	O
,	O
developed	O
earlier	O
and	O
still	O
used	O
for	O
the	O
highest	O
possible	O
image	O
quality	O
,	O
use	O
a	O
photomultiplier	O
tube	O
(	O
PMT	O
)	O
as	O
the	O
image	O
sensor	O
.	O
</s>
<s>
A	O
rotary	O
scanner	O
,	O
used	O
for	O
high-speed	O
document	B-Application
scanning	I-Application
,	O
is	O
a	O
type	O
of	O
drum	O
scanner	O
that	O
uses	O
a	O
CCD	B-Algorithm
array	I-Algorithm
instead	O
of	O
a	O
photomultiplier	O
.	O
</s>
<s>
Non-contact	O
planetary	B-Device
scanners	I-Device
essentially	O
photograph	O
delicate	O
books	O
and	O
documents	O
.	O
</s>
<s>
All	O
these	O
scanners	O
produce	O
two-dimensional	O
images	O
of	O
subjects	O
that	O
are	O
usually	O
flat	O
,	O
but	O
sometimes	O
solid	O
;	O
3D	B-Algorithm
scanners	I-Algorithm
produce	O
information	O
on	O
the	O
three-dimensional	O
structure	O
of	O
solid	O
objects	O
.	O
</s>
<s>
Digital	B-Device
cameras	I-Device
can	O
be	O
used	O
for	O
the	O
same	O
purposes	O
as	O
dedicated	O
scanners	O
.	O
</s>
<s>
Resolution	B-Algorithm
is	O
sufficient	O
for	O
less	O
demanding	O
applications	O
.	O
</s>
<s>
Digital	B-Device
cameras	I-Device
offer	O
advantages	O
of	O
speed	O
,	O
portability	O
and	O
non-contact	O
digitizing	O
of	O
thick	O
documents	O
without	O
damaging	O
the	O
book	O
spine	O
.	O
</s>
<s>
In	O
2010	O
scanning	O
technologies	O
were	O
combining	O
3D	B-Algorithm
scanners	I-Algorithm
with	O
digital	B-Device
cameras	I-Device
to	O
create	O
full-color	O
,	O
photo-realistic	O
3D	O
models	O
of	O
objects	O
.	O
</s>
<s>
memory	B-Device
cards	I-Device
and	O
USB	B-Protocol
sticks	O
)	O
.	O
</s>
<s>
These	O
scanners	O
are	O
high-resolution	B-Algorithm
systems	O
(	O
up	O
to	O
1µm/	O
pixel	B-Algorithm
)	O
,	O
similar	O
to	O
microscopes	O
.	O
</s>
<s>
The	O
detection	O
is	O
done	O
via	O
CCD	B-Algorithm
or	O
a	O
photomultiplier	O
tubes	O
.	O
</s>
<s>
They	O
send	O
a	O
linear	O
analog	O
AM	B-Device
signal	I-Device
through	O
standard	O
telephone	O
voice	O
lines	O
to	O
receptors	O
,	O
which	O
synchronously	O
print	O
the	O
proportional	O
intensity	O
on	O
special	O
paper	O
.	O
</s>
<s>
Drum	O
scanners	O
capture	O
image	O
information	O
with	O
photomultiplier	O
tubes	O
(	O
PMT	O
)	O
,	O
rather	O
than	O
the	O
charge-coupled	B-Algorithm
device	I-Algorithm
(	O
CCD	B-Algorithm
)	O
arrays	O
found	O
in	O
flatbed	O
scanners	O
and	O
inexpensive	O
film	B-Device
scanners	I-Device
.	O
</s>
<s>
Photomultipliers	O
offer	O
superior	O
dynamic	O
range	O
and	O
for	O
this	O
reason	O
drum	O
scanners	O
can	O
extract	O
more	O
detail	O
from	O
very	O
dark	O
shadow	O
areas	O
of	O
a	O
transparency	O
than	O
flatbed	O
scanners	O
using	O
CCD	B-Algorithm
sensors	I-Algorithm
.	O
</s>
<s>
The	O
smaller	O
dynamic	O
range	O
of	O
the	O
CCD	B-Algorithm
sensors	I-Algorithm
,	O
versus	O
photomultiplier	O
tubes	O
,	O
can	O
lead	O
to	O
loss	O
of	O
shadow	O
detail	O
,	O
especially	O
when	O
scanning	O
very	O
dense	O
transparency	O
film	O
.	O
</s>
<s>
The	O
sample	O
size	O
is	O
the	O
area	O
that	O
the	O
scanner	O
encoder	O
reads	O
to	O
create	O
an	O
individual	O
pixel	B-Algorithm
.	O
</s>
<s>
While	O
prices	O
of	O
both	O
new	O
and	O
used	O
units	O
dropped	O
from	O
the	O
start	O
of	O
the	O
21st	O
century	O
,	O
they	O
were	O
still	O
much	O
more	O
costly	O
than	O
CCD	B-Algorithm
flatbed	O
and	O
film	B-Device
scanners	I-Device
.	O
</s>
<s>
However	O
,	O
drum	O
scanners	O
with	O
their	O
superior	O
resolution	B-Algorithm
(	O
up	O
to	O
24,000	O
PPI	B-Algorithm
)	O
,	O
color	O
gradation	O
,	O
and	O
value	O
structure	O
continued	O
to	O
be	O
used	O
for	O
scanning	O
images	O
to	O
be	O
enlarged	O
,	O
and	O
for	O
museum-quality	O
archiving	O
of	O
photographs	O
and	O
print	O
production	O
of	O
high-quality	O
books	O
and	O
magazine	O
advertisements	O
.	O
</s>
<s>
"	O
A	O
flatbed	O
scanner	O
is	O
usually	O
composed	O
of	O
a	O
glass	O
pane	O
(	O
or	O
platen	O
)	O
,	O
under	O
which	O
there	O
is	O
a	O
bright	O
light	O
(	O
often	O
xenon	B-Protocol
,	O
LED	O
or	O
cold	O
cathode	O
fluorescent	O
)	O
which	O
illuminates	O
the	O
pane	O
,	O
and	O
a	O
moving	O
optical	O
array	O
in	O
CCD	B-Algorithm
scanning	O
.	O
</s>
<s>
CCD-type	O
scanners	O
typically	O
contain	O
three	O
rows	O
(	O
arrays	O
)	O
of	O
sensors	O
with	O
red	O
,	O
green	O
,	O
and	O
blue	O
filters.	O
"	O
</s>
<s>
"	O
Usually	O
,	O
uncut	O
film	O
strips	O
of	O
up	O
to	O
six	O
frames	O
,	O
or	O
four	O
mounted	O
slides	O
,	O
are	O
inserted	O
in	O
a	O
carrier	O
,	O
which	O
is	O
moved	O
by	O
a	O
stepper	B-Algorithm
motor	I-Algorithm
across	O
a	O
lens	O
and	O
CCD	B-Algorithm
sensor	I-Algorithm
inside	O
the	O
scanner	O
.	O
</s>
<s>
Film	B-Device
scanners	I-Device
vary	O
a	O
great	O
deal	O
in	O
price	O
and	O
quality.	O
"	O
</s>
<s>
The	O
lowest-cost	O
dedicated	O
film	B-Device
scanners	I-Device
can	O
be	O
had	O
for	O
less	O
than	O
$50	O
and	O
they	O
might	O
be	O
sufficient	O
for	O
modest	O
needs	O
.	O
</s>
<s>
Some	O
are	O
portable	O
,	O
powered	O
by	O
batteries	O
and	O
with	O
their	O
own	O
storage	O
,	O
eventually	O
transferring	O
stored	O
scans	O
to	O
a	O
computer	O
over	O
a	O
USB	B-Protocol
or	O
other	O
interface	O
.	O
</s>
<s>
3D	B-Algorithm
scanners	I-Algorithm
collect	O
data	O
on	O
the	O
three-dimensional	O
shape	O
and	O
appearance	O
of	O
an	O
object	O
.	O
</s>
<s>
Planetary	B-Device
scanners	I-Device
scan	O
a	O
delicate	O
object	O
without	O
physical	O
contact	O
.	O
</s>
<s>
There	O
are	O
two	O
different	O
types	O
:	O
document	O
and	O
3D	B-Algorithm
scanners	I-Algorithm
.	O
</s>
<s>
They	O
typically	O
have	O
a	O
"	O
start	O
"	O
button	O
,	O
which	O
is	O
held	O
by	O
the	O
user	O
for	O
the	O
duration	O
of	O
the	O
scan	O
;	O
some	O
switches	O
to	O
set	O
the	O
optical	O
resolution	B-Algorithm
;	O
and	O
a	O
roller	O
,	O
which	O
generates	O
a	O
clock	O
pulse	O
for	O
synchronization	O
with	O
the	O
computer	O
.	O
</s>
<s>
In	O
the	O
early	O
1990s	O
many	O
hand	O
scanners	O
had	O
a	O
proprietary	B-Device
interface	O
module	O
specific	O
to	O
a	O
particular	O
type	O
of	O
computer	O
,	O
such	O
as	O
an	O
Atari	B-Device
ST	I-Device
or	O
Commodore	B-Device
Amiga	I-Device
.	O
</s>
<s>
Since	O
the	O
introduction	O
of	O
the	O
USB	B-Protocol
standard	O
,	O
it	O
is	O
the	O
interface	O
most	O
commonly	O
used	O
.	O
</s>
<s>
Handheld	O
3D	B-Algorithm
scanners	I-Algorithm
are	O
used	O
in	O
industrial	O
design	O
,	O
reverse	O
engineering	O
,	O
inspection	O
and	O
analysis	O
,	O
digital	O
manufacturing	O
and	O
medical	O
applications	O
.	O
</s>
<s>
"	O
To	O
compensate	O
for	O
the	O
uneven	O
motion	O
of	O
the	O
human	O
hand	O
,	O
most	O
3D	B-Algorithm
scanning	I-Algorithm
systems	O
rely	O
on	O
the	O
placement	O
of	O
reference	O
markers	O
,	O
typically	O
adhesive	O
reflective	O
tabs	O
that	O
the	O
scanner	O
uses	O
to	O
align	O
elements	O
and	O
mark	O
positions	O
in	O
space.	O
"	O
</s>
<s>
Image	B-Application
scanners	I-Application
are	O
usually	O
used	O
in	O
conjunction	O
with	O
a	O
computer	O
which	O
controls	O
the	O
scanner	O
and	O
stores	O
scans	O
.	O
</s>
<s>
The	O
higher-resolution	O
cameras	O
fitted	O
to	O
some	O
smartphones	O
can	O
produce	O
reasonable	O
quality	O
document	O
scans	O
by	O
taking	O
a	O
photograph	O
with	O
the	O
phone	O
's	O
camera	O
and	O
post-processing	O
it	O
with	O
a	O
scanning	O
app	O
,	O
a	O
range	O
of	O
which	O
are	O
available	O
for	O
most	O
phone	O
operating	B-General_Concept
systems	I-General_Concept
,	O
to	O
whiten	O
the	O
background	O
of	O
a	O
page	O
,	O
correct	O
perspective	O
distortion	O
so	O
that	O
the	O
shape	O
of	O
a	O
rectangular	O
document	O
is	O
corrected	O
,	O
convert	O
to	O
black-and-white	O
,	O
etc	O
.	O
</s>
<s>
Some	O
smartphone	O
scanning	O
apps	O
can	O
save	O
documents	O
directly	O
to	O
online	O
storage	O
locations	O
,	O
such	O
as	O
Dropbox	B-Application
and	O
Evernote	B-Application
,	O
send	O
via	O
email	O
or	O
fax	O
documents	O
via	O
email-to-fax	O
gateways	O
.	O
</s>
<s>
Photo	B-Application
scanning	I-Application
apps	O
that	O
output	O
JPEG	O
files	O
,	O
and	O
have	O
editing	O
functions	O
useful	O
for	O
photo	O
rather	O
than	O
document	O
editing	O
;	O
</s>
<s>
This	O
data	O
is	O
then	O
processed	O
with	O
some	O
proprietary	B-Device
algorithm	O
to	O
correct	O
for	O
different	O
exposure	O
conditions	O
,	O
and	O
sent	O
to	O
the	O
computer	O
via	O
the	O
device	O
's	O
input/output	B-General_Concept
interface	O
(	O
usually	O
USB	B-Protocol
,	O
previous	O
to	O
which	O
was	O
SCSI	B-Architecture
or	O
bidirectional	O
parallel	B-Device
port	I-Device
in	O
older	O
units	O
)	O
.	O
</s>
<s>
High	B-General_Concept
quality	I-General_Concept
models	O
have	O
36-48	O
bits	O
of	O
color	O
depth	O
.	O
</s>
<s>
Another	O
qualifying	O
parameter	O
for	O
a	O
scanner	O
is	O
its	O
resolution	B-Algorithm
,	O
measured	O
in	O
pixels	B-Algorithm
per	I-Algorithm
inch	I-Algorithm
(	O
ppi	B-Algorithm
)	O
,	O
sometimes	O
more	O
accurately	O
referred	O
to	O
as	O
Samples	B-Device
per	I-Device
inch	I-Device
(	O
spi	O
)	O
.	O
</s>
<s>
Instead	O
of	O
using	O
the	O
scanner	O
's	O
true	O
optical	O
resolution	B-Algorithm
,	O
the	O
only	O
meaningful	O
parameter	O
,	O
manufacturers	O
like	O
to	O
refer	O
to	O
the	O
interpolated	O
resolution	B-Algorithm
,	O
which	O
is	O
much	O
higher	O
thanks	O
to	O
software	O
interpolation	B-Algorithm
.	O
</s>
<s>
,	O
a	O
high-end	O
flatbed	O
scanner	O
can	O
scan	O
up	O
to	O
5400	O
ppi	B-Algorithm
and	O
drum	O
scanners	O
have	O
an	O
optical	O
resolution	B-Algorithm
of	O
between	O
3,000	O
and	O
24,000	O
ppi	B-Algorithm
.	O
</s>
<s>
"	O
Effective	O
resolution	B-Algorithm
"	O
is	O
the	O
true	O
resolution	B-Algorithm
of	O
a	O
scanner	O
,	O
and	O
is	O
determined	O
by	O
using	O
a	O
resolution	B-Algorithm
test	O
chart	O
.	O
</s>
<s>
The	O
effective	O
resolution	B-Algorithm
of	O
most	O
all	O
consumer	O
flatbed	O
scanners	O
is	O
considerably	O
lower	O
than	O
the	O
manufactures	O
 '	O
given	O
optical	O
resolution	B-Algorithm
.	O
</s>
<s>
Example	O
is	O
the	O
Epson	O
V750	O
Pro	O
with	O
an	O
optical	O
resolution	B-Algorithm
given	O
by	O
manufacturer	O
as	O
being	O
4800dpi	O
and	O
6400dpi	O
(	O
dual	O
lens	O
)	O
,	O
but	O
tested	O
"	O
According	O
to	O
this	O
we	O
get	O
a	O
resolution	B-Algorithm
of	O
only	O
about	O
2300	O
dpi	O
-	O
that	O
's	O
just	O
40%	O
of	O
the	O
claimed	O
resolution	B-Algorithm
!	O
"	O
</s>
<s>
Dynamic	O
range	O
is	O
claimed	O
to	O
be	O
4.0	O
Dmax	O
,	O
but	O
"	O
Regarding	O
the	O
density	O
range	O
of	O
the	O
Epson	O
Perfection	O
V750	O
Pro	O
,	O
which	O
is	O
indicated	O
as	O
4.0	O
,	O
one	O
must	O
say	O
that	O
here	O
it	O
does	O
n't	O
reach	O
the	O
high-quality	O
 [ of ] 	O
film	B-Device
scanners	I-Device
either.	O
"	O
</s>
<s>
Manufacturers	O
often	O
claim	O
interpolated	O
resolutions	O
as	O
high	O
as	O
19,200	O
ppi	B-Algorithm
;	O
but	O
such	O
numbers	O
carry	O
little	O
meaningful	O
value	O
,	O
because	O
the	O
number	O
of	O
possible	O
interpolated	B-Algorithm
pixels	I-Algorithm
is	O
unlimited	O
and	O
doing	O
so	O
does	O
not	O
increase	O
the	O
level	O
of	O
captured	O
detail	O
.	O
</s>
<s>
The	O
size	O
of	O
the	O
file	O
created	O
increases	O
with	O
the	O
square	O
of	O
the	O
resolution	B-Algorithm
;	O
doubling	O
the	O
resolution	B-Algorithm
quadruples	O
the	O
file	O
size	O
.	O
</s>
<s>
A	O
resolution	B-Algorithm
must	O
be	O
chosen	O
that	O
is	O
within	O
the	O
capabilities	O
of	O
the	O
equipment	O
,	O
preserves	O
sufficient	O
detail	O
,	O
and	O
does	O
not	O
produce	O
a	O
file	O
of	O
excessive	O
size	O
.	O
</s>
<s>
The	O
file	O
size	O
can	O
be	O
reduced	O
for	O
a	O
given	O
resolution	B-Algorithm
by	O
using	O
"	O
lossy	O
"	O
compression	O
methods	O
such	O
as	O
JPEG	O
,	O
at	O
some	O
cost	O
in	O
quality	O
.	O
</s>
<s>
Drum	O
scanners	O
are	O
said	O
to	O
produce	O
the	O
purest	O
digital	O
representations	O
of	O
the	O
film	O
,	O
followed	O
by	O
high	O
end	O
film	B-Device
scanners	I-Device
that	O
use	O
the	O
larger	O
Kodak	O
Tri-Linear	O
sensors	O
.	O
</s>
<s>
Consumer-level	O
flatbed	O
photo	B-Application
scanners	I-Application
have	O
a	O
dynamic	O
range	O
in	O
the	O
2.0	O
–	O
3.0	O
range	O
,	O
which	O
can	O
be	O
inadequate	O
for	O
scanning	O
all	O
types	O
of	O
photographic	O
film	O
,	O
as	O
Dmax	O
can	O
be	O
and	O
often	O
is	O
between	O
3.0d	O
and	O
4.0d	O
with	O
traditional	O
black-and-white	O
film	O
.	O
</s>
<s>
Dedicated	O
film	B-Device
scanners	I-Device
have	O
a	O
dynamic	O
range	O
between	O
3.0d	O
–	O
4.0d	O
.	O
</s>
<s>
Parallel	B-Device
port	I-Device
-	O
Connecting	O
through	O
a	O
parallel	B-Device
port	I-Device
is	O
the	O
slowest	O
common	O
transfer	O
method	O
.	O
</s>
<s>
Early	O
scanners	O
had	O
parallel	B-Device
port	I-Device
connections	O
that	O
could	O
not	O
transfer	O
data	O
faster	O
than	O
70	O
kilobytes/second	O
.	O
</s>
<s>
The	O
primary	O
advantage	O
of	O
the	O
parallel	B-Device
port	I-Device
connection	O
was	O
economic	O
and	O
user	O
skill	O
level	O
:	O
it	O
avoided	O
adding	O
an	O
interface	O
card	O
to	O
the	O
computer	O
.	O
</s>
<s>
Certain	O
drumscanners	O
like	O
the	O
Howtek	O
D4000	O
featured	O
both	O
a	O
SCSI	B-Architecture
and	O
GPIB	O
interface	O
.	O
</s>
<s>
For	O
Apple	O
Macintosh	B-Application
systems	I-Application
,	O
National	O
Instruments	O
provided	O
a	O
NuBus	B-Device
GPIB	O
interface	O
card	O
.	O
</s>
<s>
Small	B-Architecture
Computer	I-Architecture
System	I-Architecture
Interface	I-Architecture
(	O
SCSI	B-Architecture
)	O
,	O
rarely	O
used	O
since	O
the	O
early	O
21st	O
century	O
,	O
supported	O
only	O
by	O
computers	O
with	O
a	O
SCSI	B-Architecture
interface	O
,	O
either	O
on	O
a	O
card	O
or	O
built-in	O
.	O
</s>
<s>
During	O
the	O
evolution	O
of	O
the	O
SCSI	B-Architecture
standard	O
,	O
speeds	O
increased	O
.	O
</s>
<s>
Widely	O
available	O
and	O
easily	O
set	O
up	O
USB	B-Protocol
and	O
Firewire	B-Protocol
largely	O
supplanted	O
SCSI	B-Architecture
.	O
</s>
<s>
Universal	O
Serial	O
Bus	O
(	O
USB	B-Protocol
)	O
scanners	O
can	O
transfer	O
data	O
quickly	O
.	O
</s>
<s>
The	O
early	O
USB	B-Protocol
1.1	O
standard	O
could	O
transfer	O
data	O
at	O
1.5	O
megabytes	O
per	O
second	O
(	O
slower	O
than	O
SCSI	B-Architecture
)	O
,	O
but	O
the	O
later	O
USB	B-Protocol
2.0/3.0	O
standards	O
can	O
transfer	O
at	O
more	O
than	O
20/60	O
megabytes	O
per	O
second	O
in	O
practice	O
.	O
</s>
<s>
FireWire	B-Protocol
,	O
or	O
IEEE-1394	B-Protocol
,	O
is	O
an	O
interface	O
of	O
comparable	O
speed	O
to	O
USB	B-Protocol
2.0	O
.	O
</s>
<s>
Possible	O
FireWire	B-Protocol
speeds	O
are	O
25	O
,	O
50	O
,	O
and	O
100	O
,	O
400	O
and	O
800	O
megabits	O
per	O
second	O
,	O
but	O
devices	O
may	O
not	O
support	O
all	O
speeds	O
.	O
</s>
<s>
Proprietary	B-Device
interfaces	O
were	O
used	O
on	O
some	O
early	O
scanners	O
that	O
used	O
a	O
proprietary	B-Device
interface	O
card	O
rather	O
than	O
a	O
standard	O
interface	O
.	O
</s>
<s>
During	O
the	O
early	O
1990s	O
professional	O
flatbed	O
scanners	O
were	O
available	O
over	O
a	O
local	B-General_Concept
computer	I-General_Concept
network	I-General_Concept
.	O
</s>
<s>
Battery-powered	O
portable	O
scanners	O
store	O
scans	O
on	O
internal	O
memory	O
;	O
they	O
can	O
later	O
be	O
transferred	O
to	O
a	O
computer	O
either	O
by	O
direct	O
connection	O
,	O
typically	O
USB	B-Protocol
,	O
or	O
in	O
some	O
cases	O
a	O
memory	B-Device
card	I-Device
may	O
be	O
removed	O
from	O
the	O
scanner	O
and	O
plugged	O
into	O
the	O
computer	O
.	O
</s>
<s>
A	O
paint	O
application	O
such	O
as	O
GIMP	B-Application
or	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
must	O
communicate	O
with	O
the	O
scanner	O
.	O
</s>
<s>
In	O
order	O
to	O
simplify	O
applications	O
programming	O
,	O
some	O
Applications	B-Application
programming	I-Application
interfaces	I-Application
(	O
"	O
API	B-Application
"	O
)	O
were	O
developed	O
.	O
</s>
<s>
The	O
API	B-Application
presents	O
a	O
uniform	O
interface	O
to	O
the	O
scanner	O
.	O
</s>
<s>
For	O
example	O
,	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
supports	O
the	O
TWAIN	B-Application
standard	O
;	O
therefore	O
in	O
theory	O
Photoshop	B-Operating_System
can	O
acquire	O
an	O
image	O
from	O
any	O
scanner	O
that	O
has	O
a	O
TWAIN	B-Application
driver	O
.	O
</s>
<s>
Either	O
the	O
application	O
or	O
the	O
scanner	O
manufacturer	O
(	O
or	O
both	O
)	O
may	O
have	O
faults	O
in	O
their	O
implementation	O
of	O
the	O
API	B-Application
.	O
</s>
<s>
Typically	O
,	O
the	O
API	B-Application
is	O
implemented	O
as	O
a	O
dynamically	B-Library
linked	I-Library
library	I-Library
.	O
</s>
<s>
Each	O
scanner	O
manufacturer	O
provides	O
software	O
that	O
translates	O
the	O
API	B-Application
procedure	O
calls	O
into	O
primitive	O
commands	O
that	O
are	O
issued	O
to	O
a	O
hardware	O
controller	O
(	O
such	O
as	O
the	O
SCSI	B-Architecture
,	O
USB	B-Protocol
,	O
or	O
FireWire	B-Protocol
controller	O
)	O
.	O
</s>
<s>
The	O
manufacturer	O
's	O
part	O
of	O
the	O
API	B-Application
is	O
commonly	O
called	O
a	O
device	B-Application
driver	I-Application
,	O
but	O
that	O
designation	O
is	O
not	O
strictly	O
accurate	O
:	O
the	O
API	B-Application
does	O
not	O
run	O
in	O
kernel	O
mode	O
and	O
does	O
not	O
directly	O
access	O
the	O
device	O
.	O
</s>
<s>
Rather	O
the	O
scanner	O
API	B-Application
library	O
translates	O
application	O
requests	O
into	O
hardware	O
requests	O
.	O
</s>
<s>
Common	O
scanner	O
software	B-Application
API	I-Application
interfaces	O
:	O
</s>
<s>
SANE	B-Application
(	O
Scanner	B-Application
Access	I-Application
Now	I-Application
Easy	I-Application
)	O
is	O
a	O
free/open	O
-source	O
API	B-Application
for	O
accessing	O
scanners	O
.	O
</s>
<s>
Originally	O
developed	O
for	O
Unix	B-Application
and	O
Linux	B-Application
operating	I-Application
systems	I-Application
,	O
it	O
has	O
been	O
ported	O
to	O
OS/2	B-Application
,	O
Mac	B-Application
OS	I-Application
X	I-Application
,	O
and	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Unlike	O
TWAIN	B-Application
,	O
SANE	B-Application
does	O
not	O
handle	O
the	O
user	O
interface	O
.	O
</s>
<s>
This	O
allows	O
batch	O
scans	O
and	O
transparent	O
network	O
access	O
without	O
any	O
special	O
support	O
from	O
the	O
device	B-Application
driver	I-Application
.	O
</s>
<s>
TWAIN	B-Application
is	O
used	O
by	O
most	O
scanners	O
.	O
</s>
<s>
ISIS	O
(	O
Image	O
and	O
Scanner	O
Interface	O
Specification	O
)	O
created	O
by	O
Pixel	B-Algorithm
Translations	O
,	O
which	O
still	O
uses	O
SCSI-II	O
for	O
performance	O
reasons	O
,	O
is	O
used	O
by	O
large	O
,	O
departmental-scale	O
,	O
machines	O
.	O
</s>
<s>
WIA	B-Device
(	O
Windows	B-Device
Image	I-Device
Acquisition	I-Device
)	O
is	O
an	O
API	B-Application
provided	O
by	O
Microsoft	O
for	O
use	O
on	O
Microsoft	B-Application
Windows	I-Application
.	O
</s>
<s>
Typically	O
,	O
in	O
addition	O
to	O
the	O
scanning	O
utility	O
,	O
some	O
type	O
of	O
image-editing	O
application	O
(	O
such	O
as	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
)	O
,	O
and	O
optical	B-Application
character	I-Application
recognition	I-Application
(	O
OCR	B-Application
)	O
software	O
are	O
supplied	O
.	O
</s>
<s>
OCR	B-Application
software	O
converts	O
graphical	O
images	O
of	O
text	O
into	O
standard	O
text	O
that	O
can	O
be	O
edited	O
using	O
common	O
word-processing	O
and	O
text-editing	O
software	O
;	O
accuracy	O
is	O
rarely	O
perfect	O
.	O
</s>
<s>
Some	O
scanners	O
compress	O
and	O
clean	O
up	O
the	O
image	O
using	O
embedded	O
firmware	B-Application
.	O
</s>
<s>
Once	O
on	O
the	O
computer	O
,	O
the	O
image	O
can	O
be	O
processed	O
with	O
a	O
raster	B-Algorithm
graphics	I-Algorithm
program	O
(	O
such	O
as	O
Adobe	B-Operating_System
Photoshop	I-Operating_System
or	O
the	B-Application
GIMP	I-Application
)	O
and	O
saved	O
on	O
a	O
storage	O
device	O
(	O
such	O
as	O
a	O
hard	B-Device
disk	I-Device
)	O
.	O
</s>
<s>
Images	O
are	O
usually	O
stored	O
on	O
a	O
hard	B-Device
disk	I-Device
.	O
</s>
<s>
Documents	O
are	O
best	O
stored	O
in	O
TIFF	O
or	O
PDF	B-Application
format	I-Application
;	O
JPEG	O
is	O
particularly	O
unsuitable	O
for	O
text	O
.	O
</s>
<s>
Optical	B-Application
character	I-Application
recognition	I-Application
(	O
OCR	B-Application
)	O
software	O
allows	O
a	O
scanned	B-Application
image	I-Application
of	O
text	O
to	O
be	O
converted	O
into	O
editable	O
text	O
with	O
reasonable	O
accuracy	O
,	O
so	O
long	O
as	O
the	O
text	O
is	O
cleanly	O
printed	O
and	O
in	O
a	O
typeface	O
and	O
size	O
that	O
can	O
be	O
read	O
by	O
the	O
software	O
.	O
</s>
<s>
OCR	B-Application
capability	O
may	O
be	O
integrated	O
into	O
the	O
scanning	O
software	O
,	O
or	O
the	O
scanned	B-Application
image	I-Application
file	O
can	O
be	O
processed	O
with	O
a	O
separate	O
OCR	B-Application
program	O
.	O
</s>
<s>
Document	B-Application
imaging	I-Application
requirements	O
differ	O
from	O
those	O
of	O
image	B-Application
scanning	I-Application
.	O
</s>
<s>
On	O
the	O
other	O
hand	O
,	O
image	B-Application
scanning	I-Application
typically	O
requires	O
the	O
ability	O
to	O
handle	O
fragile	O
and	O
or	O
three	O
dimensional	O
objects	O
as	O
well	O
as	O
scan	O
at	O
a	O
much	O
higher	O
resolution	B-Algorithm
.	O
</s>
<s>
Document	O
scanners	O
have	O
document	B-Device
feeders	I-Device
,	O
usually	O
larger	O
than	O
those	O
sometimes	O
found	O
on	O
copiers	O
or	O
all-purpose	O
scanners	O
.	O
</s>
<s>
Sophisticated	O
document	O
scanners	O
have	O
firmware	B-Application
or	O
software	O
that	O
cleans	O
up	O
scans	O
of	O
text	O
as	O
they	O
are	O
produced	O
,	O
eliminating	O
accidental	O
marks	O
and	O
sharpening	O
type	O
;	O
this	O
would	O
be	O
unacceptable	O
for	O
photographic	O
work	O
,	O
where	O
marks	O
cannot	O
reliably	O
be	O
distinguished	O
from	O
desired	O
fine	O
detail	O
.	O
</s>
<s>
The	O
resolution	B-Algorithm
used	O
is	O
usually	O
from	O
150	O
to	O
300	O
dpi	O
,	O
although	O
the	O
hardware	O
may	O
be	O
capable	O
of	O
600	O
or	O
higher	O
resolution	B-Algorithm
;	O
this	O
produces	O
images	O
of	O
text	O
good	O
enough	O
to	O
read	O
and	O
for	O
optical	B-Application
character	I-Application
recognition	I-Application
(	O
OCR	B-Application
)	O
,	O
without	O
the	O
higher	O
demands	O
on	O
storage	O
space	O
required	O
by	O
higher-resolution	O
images	O
.	O
</s>
<s>
Document	O
scans	O
are	O
often	O
processed	O
using	O
OCR	B-Application
technology	O
to	O
create	O
editable	O
and	O
searchable	O
files	O
.	O
</s>
<s>
Most	O
scanners	O
use	O
ISIS	O
or	O
TWAIN	B-Application
device	B-Application
drivers	I-Application
to	O
scan	O
documents	O
into	O
TIFF	O
format	O
so	O
that	O
the	O
scanned	O
pages	O
can	O
be	O
fed	O
into	O
a	O
document	O
management	O
system	O
that	O
will	O
handle	O
the	O
archiving	O
and	O
retrieval	O
of	O
the	O
scanned	O
pages	O
.	O
</s>
<s>
This	O
process	O
can	O
sometimes	O
be	O
automated	O
to	O
some	O
extent	O
,	O
but	O
it	O
often	O
requires	O
manual	O
labour	O
performed	O
by	O
data-entry	B-General_Concept
clerks	I-General_Concept
.	O
</s>
<s>
A	O
specialized	O
form	O
of	O
document	B-Application
scanning	I-Application
is	O
book	O
scanning	O
.	O
</s>
<s>
Capturing	O
images	O
on	O
document	O
cameras	O
differs	O
from	O
that	O
of	O
flatbed	O
and	O
Automatic	B-Device
document	I-Device
feeder	I-Device
(	O
ADF	O
)	O
scanners	O
in	O
that	O
there	O
are	O
no	O
moving	O
parts	O
required	O
to	O
scan	O
the	O
object	O
.	O
</s>
<s>
Document	O
cameras	O
can	O
be	O
integrated	O
directly	O
into	O
a	O
Workflow	B-Operating_System
or	O
process	O
,	O
for	O
example	O
a	O
teller	O
at	O
a	O
bank	O
.	O
</s>
<s>
For	O
example	O
,	O
Epson	O
,	O
Minolta	O
,	O
Nikon	B-Algorithm
,	O
Konica	O
Minolta	O
,	O
Microtek	O
,	O
and	O
others	O
use	O
Digital	O
ICE	O
,	O
while	O
Canon	O
uses	O
its	O
own	O
system	O
FARE	O
(	O
Film	O
Automatic	O
Retouching	O
and	O
Enhancement	O
system	O
)	O
.	O
</s>
<s>
Flatbed	O
scanners	O
have	O
been	O
used	O
as	O
digital	B-Algorithm
backs	I-Algorithm
for	O
large-format	O
cameras	O
to	O
create	O
high-resolution	B-Algorithm
digital	B-Algorithm
images	I-Algorithm
of	O
static	O
subjects	O
.	O
</s>
<s>
A	O
modified	O
flatbed	O
scanner	O
has	O
been	O
used	O
for	O
documentation	O
and	O
quantification	O
of	O
thin	O
layer	O
chromatograms	O
detected	O
by	O
fluorescence	O
quenching	O
on	O
silica	O
gel	O
layers	O
containing	O
an	O
ultraviolet	B-Application
(	O
UV	O
)	O
indicator	O
.	O
</s>
