<s>
Picture	B-Algorithm
Transfer	I-Algorithm
Protocol	I-Algorithm
(	O
PTP	O
)	O
is	O
a	O
protocol	O
developed	O
by	O
the	O
International	O
Imaging	O
Industry	O
Association	O
to	O
allow	O
the	O
transfer	O
of	O
images	O
from	O
digital	B-Device
cameras	I-Device
to	O
computers	O
and	O
other	O
peripheral	O
devices	O
without	O
the	O
need	O
of	O
additional	O
device	B-Application
drivers	I-Application
.	O
</s>
<s>
The	O
protocol	O
has	O
been	O
standardized	O
as	O
ISO	B-Algorithm
15740	I-Algorithm
.	O
</s>
<s>
It	O
is	O
further	O
standardized	O
for	O
USB	B-Protocol
by	O
the	O
USB	B-Protocol
Implementers	O
Forum	O
as	O
the	O
still	O
image	O
capture	O
device	O
class	O
.	O
</s>
<s>
USB	B-Protocol
is	O
the	O
default	O
network	O
transport	O
media	O
for	O
PTP	O
devices	O
.	O
</s>
<s>
USB	B-Algorithm
PTP	I-Algorithm
is	O
a	O
common	O
alternative	O
to	O
the	O
USB	B-Architecture
mass-storage	I-Architecture
device	I-Architecture
class	I-Architecture
(	O
USB	B-Architecture
MSC	I-Architecture
)	O
,	O
as	O
a	O
digital	B-Device
camera	I-Device
connection	O
protocol	O
.	O
</s>
<s>
While	O
it	O
is	O
common	O
to	O
think	O
of	O
the	O
objects	O
that	O
PTP	O
handle	O
as	O
files	B-Operating_System
,	O
they	O
are	O
abstract	O
entities	O
identified	O
solely	O
by	O
a	O
32-bit	O
object	O
ID	O
.	O
</s>
<s>
Until	O
the	O
standardization	O
of	O
PTP	O
,	O
digital	B-Device
camera	I-Device
vendors	O
used	O
different	O
proprietary	O
protocols	O
for	O
controlling	O
digital	B-Device
cameras	I-Device
and	O
transferring	O
images	O
to	O
computers	O
and	O
other	O
host	O
devices	O
.	O
</s>
<s>
The	O
term	O
"	O
Picture	B-Algorithm
Transfer	I-Algorithm
Protocol	I-Algorithm
"	O
and	O
the	O
acronym	O
"	O
PTP	O
"	O
were	O
both	O
coined	O
by	O
Steve	O
Mann	O
,	O
summarizing	O
work	O
on	O
the	O
creation	O
of	O
a	O
Linux-friendly	O
way	O
of	O
transferring	O
pictures	O
to	O
and	O
from	O
home-made	O
wearable	O
computers	O
,	O
at	O
a	O
time	O
when	O
most	O
cameras	O
required	O
the	O
use	O
of	O
Microsoft	B-Application
Windows	I-Application
or	O
Mac	O
OS	O
device	B-Application
drivers	I-Application
to	O
transfer	O
their	O
pictures	O
to	O
a	O
computer	O
.	O
</s>
<s>
However	O
,	O
it	O
is	O
designed	O
to	O
support	O
existing	O
standards	O
,	O
such	O
as	O
Exif	O
,	O
TIFF/EP	O
,	O
DCF	B-Algorithm
,	O
and	O
DPOF	B-Algorithm
,	O
and	O
is	O
commonly	O
implemented	O
over	O
the	O
USB	B-Protocol
and	O
FireWire	B-Protocol
transport	O
layers	O
.	O
</s>
<s>
Images	O
on	O
digital	B-Device
cameras	I-Device
are	O
generally	O
stored	O
as	O
files	B-Operating_System
on	O
a	O
mass	B-Device
storage	I-Device
device	I-Device
,	O
such	O
as	O
a	O
memory	B-Device
card	I-Device
,	O
which	O
is	O
formatted	O
with	O
a	O
file	O
system	O
,	O
most	O
commonly	O
FAT12	B-Application
,	O
FAT16	B-Application
or	O
FAT32	B-Application
,	O
which	O
may	O
be	O
laid	O
out	O
as	O
per	O
the	O
Design	B-Algorithm
rule	I-Algorithm
for	I-Algorithm
Camera	I-Algorithm
File	I-Algorithm
system	I-Algorithm
(	O
DCF	B-Algorithm
)	O
specification	O
.	O
</s>
<s>
By	O
contrast	O
,	O
if	O
a	O
camera	O
is	O
mounted	O
via	O
USB	B-Architecture
MSC	I-Architecture
,	O
the	O
physical	O
file	O
system	O
and	O
layout	O
are	O
exposed	O
to	O
the	O
user	O
.	O
</s>
<s>
Many	O
modern	O
digital	B-Device
cameras	I-Device
from	O
Canon	O
and	O
Nikon	B-Algorithm
can	O
be	O
controlled	O
via	O
PTP	O
from	O
a	O
USB	B-Protocol
host	O
enabled	O
computing	O
device	O
(	O
Smartphone	O
,	O
PC	O
or	O
Arduino	O
for	O
example	O
)	O
.	O
</s>
<s>
As	O
is	O
the	O
norm	O
for	O
PTP	O
,	O
the	O
communication	O
takes	O
place	O
over	O
a	O
USB	B-Protocol
connection	O
.	O
</s>
<s>
When	O
interacting	O
with	O
the	O
camera	O
in	O
this	O
manner	O
,	O
it	O
is	O
expected	O
that	O
the	O
USB	B-Protocol
endpoints	O
are	O
in	O
(	O
synchronous	O
)	O
Bulk	O
Transfer	O
Mode	O
,	O
for	O
getting/setting	O
virtually	O
all	O
the	O
camera	O
's	O
features/properties	O
(	O
such	O
as	O
ISO	O
,	O
Aperture	O
,	O
Shutter	O
speed	O
and	O
focus	O
)	O
.	O
</s>
<s>
Events	O
raised	O
by	O
the	O
camera	O
,	O
in	O
response	O
to	O
specific	O
actions	O
performed	O
by	O
the	O
host	O
device	O
,	O
are	O
sent	O
back	O
to	O
the	O
host	O
via	O
the	O
USB	B-Protocol
asynchronous	O
Interrupt	O
endpoint	O
.	O
</s>
<s>
As	O
described	O
above	O
,	O
the	O
storage	O
objects	O
of	O
the	O
camera	O
's	O
memory	B-Device
cards	I-Device
can	O
be	O
manipulated	O
too	O
.	O
</s>
<s>
PTP/IP	O
,	O
developed	O
by	O
FotoNation	O
and	O
first	O
implemented	O
in	O
a	O
round	O
of	O
Wi-Fi	O
digital	B-Device
cameras	I-Device
by	O
Nikon	B-Algorithm
,	O
Canon	O
,	O
and	O
Eastman	O
Kodak	O
,	O
allows	O
data	O
transfer	O
over	O
any	O
IP-based	O
network	O
.	O
</s>
<s>
Media	B-Protocol
Transfer	I-Protocol
Protocol	I-Protocol
(	O
MTP	B-Protocol
)	O
,	O
developed	O
by	O
Microsoft	O
,	O
allows	O
for	O
transfer	O
over	O
wireless	O
or	O
wired	O
networks	O
based	O
in	O
part	O
on	O
FotoNation	O
's	O
PTP/IP	O
,	O
but	O
also	O
allows	O
users	O
to	O
transfer	O
other	O
media	O
aside	O
from	O
pictures	O
,	O
as	O
well	O
as	O
for	O
tagging	O
objects	O
with	O
extended	O
metadata	O
(	O
such	O
as	O
title	O
,	O
artist	O
and	O
similar	O
)	O
.	O
</s>
<s>
Microsoft	B-Application
Windows	I-Application
has	O
supported	O
PTP	O
from	O
Windows	B-Device
ME	I-Device
onwards	O
(	O
excluding	O
Windows	B-Operating_System
CE	I-Operating_System
)	O
.	O
</s>
<s>
Microsoft	O
implements	O
PTP	O
on	O
Windows	O
through	O
Windows	B-Device
Image	I-Device
Acquisition	I-Device
.	O
</s>
<s>
A	O
disadvantage	O
of	O
PTP	O
on	O
Windows	O
as	O
compared	O
to	O
USB	B-Architecture
mass	I-Architecture
storage	I-Architecture
is	O
that	O
Windows	O
does	O
not	O
assign	O
drive	O
letters	O
to	O
PTP	O
devices	O
,	O
so	O
image	O
files	B-Operating_System
on	O
them	O
cannot	O
be	O
manipulated	O
by	O
scripts	O
or	O
standard	O
Windows	O
programs	O
,	O
only	O
by	O
Windows	O
Explorer	O
or	O
applications	O
with	O
specially	O
written	O
PTP	O
support	O
.	O
</s>
<s>
PTP	O
on	O
Linux	B-Application
and	O
other	O
free	B-Application
and	O
open-source	B-Application
operating	O
systems	O
is	O
supported	O
by	O
a	O
number	O
of	O
libraries	O
,	O
such	O
as	O
libgphoto	B-Algorithm
and	O
,	O
used	O
by	O
applications	O
such	O
as	O
digiKam	B-Language
and	O
F-Spot	B-Language
.	O
</s>
<s>
As	O
on	O
Microsoft	B-Application
Windows	I-Application
there	O
is	O
no	O
native	O
support	O
on	O
Linux	B-Application
,	O
but	O
by	O
means	O
of	O
GVfs	B-Language
the	O
devices	O
can	O
easily	O
be	O
mounted	O
and	O
made	O
available	O
to	O
applications	O
that	O
use	O
standard	O
POSIX	O
commands	O
and	O
library	O
functions	O
.	O
</s>
<s>
Android	B-Application
has	O
PTP	O
support	O
,	O
although	O
as	O
with	O
MTP	B-Protocol
,	O
a	O
limitation	O
is	O
that	O
when	O
transferring	O
photos	O
from	O
one	O
's	O
computer	O
to	O
the	O
Android	B-Application
device	O
,	O
file	O
timestamps	O
are	O
replaced	O
with	O
the	O
time	O
of	O
the	O
copy	O
(	O
with	O
copies	O
in	O
the	O
other	O
direction	O
,	O
from	O
device	O
to	O
computer	O
,	O
timestamps	O
are	O
preserved	O
)	O
.	O
</s>
<s>
The	O
Poseidon	O
USB	B-Protocol
stack	O
on	O
Amiga	B-Device
includes	O
ptp.class	O
.	O
</s>
