<s>
Design	B-Algorithm
rule	I-Algorithm
for	I-Algorithm
Camera	I-Algorithm
File	I-Algorithm
system	I-Algorithm
(	O
DCF	O
)	O
is	O
a	O
JEITA	O
specification	O
(	O
number	O
CP-3461	O
)	O
which	O
defines	O
a	O
file	B-Application
system	I-Application
for	O
digital	B-Device
cameras	I-Device
,	O
including	O
the	O
directory	B-Application
structure	O
,	O
file	O
naming	O
method	O
,	O
character	O
set	O
,	O
file	O
format	O
,	O
and	O
metadata	O
format	O
.	O
</s>
<s>
It	O
is	O
currently	O
the	O
de	O
facto	O
industry	O
standard	O
for	O
digital	B-Device
still	I-Device
cameras	I-Device
.	O
</s>
<s>
In	O
order	O
to	O
guarantee	O
interoperability	O
,	O
DCF	O
specifies	O
the	O
file	B-Application
system	I-Application
for	O
image	O
and	O
sound	O
files	O
to	O
be	O
used	O
on	O
formatted	O
DCF	O
media	O
(	O
like	O
removable	B-Device
or	O
non-removable	O
memory	O
)	O
as	O
FAT12	B-Application
,	O
FAT16	B-Application
,	O
FAT32	B-Application
,	O
or	O
exFAT	B-Application
.	O
</s>
<s>
Media	O
with	O
a	O
capacity	O
of	O
more	O
than	O
2	O
GB	O
must	O
be	O
formatted	O
using	O
FAT32	B-Application
or	O
exFAT	B-Application
.	O
</s>
<s>
The	O
DCF	O
standard	O
defines	O
that	O
the	O
"	O
Read	O
Only	O
"	O
file	O
and	O
directory	B-Application
attribute	O
of	O
FAT	O
file	B-Application
systems	I-Application
can	O
be	O
used	O
to	O
protect	O
files	O
or	O
directories	B-Application
from	O
accidental	O
deletion	O
.	O
</s>
<s>
The	O
filesystem	B-Application
in	O
a	O
digital	B-Device
camera	I-Device
contains	O
a	O
DCIM	O
(	O
digital	B-Device
camera	I-Device
images	O
)	O
directory	B-Application
,	O
which	O
can	O
contain	O
multiple	O
subdirectories	B-Application
with	O
names	O
such	O
as	O
"	O
123ABCDE	O
"	O
that	O
consist	O
of	O
a	O
unique	O
directory	B-Application
number	O
(	O
in	O
the	O
range	O
100	O
…	O
999	O
)	O
and	O
five	O
alphanumeric	O
characters	O
(	O
or	O
any	O
valid	O
filename	O
characters	O
)	O
,	O
which	O
may	O
be	O
freely	O
chosen	O
and	O
often	O
refer	O
to	O
a	O
camera	O
maker	O
.	O
</s>
<s>
These	O
directories	B-Application
contain	O
files	O
with	O
names	O
such	O
as	O
"	O
ABCD1234.JPG	O
"	O
that	O
consist	O
of	O
four	O
alphanumeric	O
characters	O
(	O
often	O
"	O
100_	O
"	O
,	O
"	O
DSC0	O
"	O
,	O
"	O
DSCF	O
"	O
,	O
"	O
IMG_	O
"	O
,	O
"	O
MOV_	O
"	O
,	O
or	O
"	O
P000	O
"	O
)	O
,	O
followed	O
by	O
a	O
number	O
in	O
the	O
range	O
0001	O
...	O
9999	O
.	O
</s>
<s>
As	O
an	O
example	O
of	O
the	O
DCF	O
structure	O
,	O
the	O
files	O
on	O
a	O
Nikon	B-Algorithm
D40	I-Algorithm
are	O
arranged	O
according	O
to	O
the	O
above	O
specification	O
.	O
</s>
<s>
Specifically	O
,	O
a	O
card	O
formatted	O
by	O
the	O
camera	O
will	O
have	O
a	O
volume	O
named	O
"	O
NIKOND40	B-Algorithm
"	O
,	O
with	O
a	O
subdirectory	B-Application
named	O
"	O
DCIM	O
"	O
.	O
</s>
<s>
This	O
directory	B-Application
contains	O
a	O
subdirectory	B-Application
named	O
by	O
default	O
"	O
100NCD40	O
"	O
,	O
in	O
which	O
images	O
are	O
stored	O
.	O
</s>
<s>
As	O
this	O
is	O
an	O
industry	O
standard	O
,	O
similar	O
directory	B-Application
structures	O
and	O
naming	O
procedures	O
can	O
be	O
found	O
in	O
most	O
digital	B-Device
cameras	I-Device
.	O
</s>
<s>
The	O
standard	O
leaves	O
room	O
for	O
varying	O
types	O
of	O
file	O
and	O
directory	B-Application
organisations	O
.	O
</s>
<s>
Some	O
manufacturers	O
choose	O
filenames	O
that	O
include	O
the	O
subdirectory	B-Application
number	O
as	O
part	O
of	O
the	O
alphanumeric	O
part	O
of	O
the	O
filename	O
.	O
</s>
<s>
For	O
example	O
,	O
for	O
some	O
of	O
their	O
camera	O
models	O
,	O
Panasonic	O
's	O
DCF	O
file	O
numbering	O
has	O
filenames	O
starting	O
with	O
"	O
P	O
"	O
(	O
for	O
"	O
Panasonic	O
"	O
)	O
,	O
followed	O
by	O
the	O
number	O
of	O
the	O
DCF	O
subdirectory	B-Application
it	O
is	O
in	O
,	O
followed	O
by	O
the	O
actual	O
image	O
number	O
,	O
only	O
ranging	O
until	O
999	O
,	O
i.e.	O
</s>
<s>
possible	O
filenames	O
are	O
P1000001	O
,	O
P1000002	O
,	O
...	O
,	O
P9990999	O
(	O
with	O
the	O
"	O
0	O
"	O
remaining	O
constant	O
between	O
files	O
,	O
serving	O
no	O
identifying	O
purpose	O
)	O
.	O
</s>
<s>
GH0100001	O
,	O
GH0100002	O
,	O
...	O
,	O
GH9990999	O
(	O
note	O
however	O
that	O
the	O
latter	O
consists	O
of	O
nine	O
characters	O
instead	O
of	O
eight	O
,	O
so	O
GoPro	O
deviates	O
from	O
the	O
DCF	O
standard	O
)	O
.	O
</s>
<s>
A	O
general	O
example	O
of	O
a	O
DCF	O
directory	B-Application
and	O
file	O
structure	O
can	O
be	O
given	O
as	O
follows	O
:	O
</s>
<s>
...	O
</s>
<s>
...	O
</s>
<s>
...	O
etc	O
.	O
</s>
<s>
Files	O
in	O
directories	B-Application
that	O
are	O
not	O
located	O
under	O
a	O
DCF	O
directory	B-Application
are	O
not	O
DCF	O
object	O
components	O
.	O
</s>
<s>
One	O
DCF	O
directory	B-Application
may	O
contain	O
up	O
to	O
9999	O
DCF	O
objects	O
,	O
numbered	O
from	O
"	O
0001	O
"	O
to	O
"	O
9999	O
"	O
(	O
except	O
for	O
some	O
manufacturers	O
like	O
Panasonic	O
which	O
number	O
from	O
"	O
0001	O
"	O
to	O
"	O
0999	O
"	O
)	O
.	O
</s>
<s>
DCF	O
media	O
is	O
defined	O
as	O
removable	B-Device
memory	O
recorded	O
in	O
compliance	O
with	O
the	O
DCF	O
specification	O
or	O
,	O
removable	B-Device
and	O
non-removable	O
memory	O
that	O
a	O
file	B-Application
system	I-Application
can	O
access	O
from	O
an	O
external	O
device	O
through	O
IF	O
(	O
regardless	O
of	O
wired	O
or	O
wireless	O
)	O
.	O
</s>
<s>
Camera	B-Algorithm
file	I-Algorithm
systems	I-Algorithm
can	O
usually	O
be	O
accessed	O
by	O
directly	O
mounting	O
them	O
via	O
the	O
USB	B-Architecture
mass	I-Architecture
storage	I-Architecture
device	I-Architecture
class	I-Architecture
protocol	O
,	O
which	O
exposes	O
the	O
file	O
layout	O
,	O
whether	O
DCF	O
compliant	O
or	O
otherwise	O
.	O
</s>
<s>
Alternatively	O
,	O
and	O
independent	O
of	O
DCF	O
,	O
files	O
may	O
be	O
accessed	O
via	O
the	O
Picture	B-Algorithm
Transfer	I-Algorithm
Protocol	I-Algorithm
,	O
which	O
provides	O
an	O
object-oriented	O
view	O
and	O
need	O
not	O
expose	O
the	O
file	O
layout	O
.	O
</s>
<s>
The	O
file	B-Application
system	I-Application
layout	O
is	O
often	O
opaque	O
to	O
users	O
,	O
as	O
images	O
are	O
copied	O
onto	O
a	O
computer	O
or	O
printer	O
and	O
the	O
application	O
deals	O
with	O
layout	O
.	O
</s>
