'Picture Transfer Protocol' ('PTP') is a widely supported protocol developed by the
International Imaging Industry Association to allow the transfer of images from digital cameras to computers and other peripheral devices without the need of additional
device drivers. The protocol has been standardised as
ISO 15740.
It is further standardized for
USB by the
USB Implementers Forum as the ''still image capture device class''. USB is the default network transport media for PTP devices. USB PTP is a common alternative to
USB MSC, as a digital camera connection protocol. Some cameras support both modes.
The PTP protocol specify a way of creating, transferring and manipulating ''objects'' which are typically photographic images such as a
JPEG file. While it is common to think of the objects that PTP handle as
files, they are abstract entities identified solely by an 32-bit object ID. These objects can however have ''parents'' and ''siblings'' so that a file system-like view of device contents can be created.
A number of protocols have been developed that extend PTP. 'PTP/IP', developed by
FotoNation and first implemented by
Nikon, allows data transfer over a wireless network.
Media Transfer Protocol, developed by
Microsoft, allows for transfer over wireless or wired networks based in part on FotoNation's PTP/IP, but also allows users to transfer other media aside from pictures, as well as for tagging objects with extended
metadata (such as title, artist and similar).
Both
Microsoft and
Apple include PTP support in their
operating systems, from
Windows Me onwards, and
Mac OS X v10.1 onwards, respectively. Microsoft implements PTP on Windows through
Windows Image Acquisition.
[1][2] PTP on
Linux and other
free software/
open source operating systems is supported by a number of libraries, such as
libgphoto and
libptp, libraries used by applications such as
digikam and
f-spot.
See also
★
PictBridge
★
Digital camera
★
Universal Serial Bus
★
USB mass storage device class USB MSC — alternative protocol for digital cameras
References
1. Windows Image Acquisition on MSDN
2. Still image connectivity for Windows
External links
★
ISO 15740, ISO.
★
Picture Transfer Protocol — PTP — Now an International Standard, I3A.
★
Microsoft and FotoNation Team to Support the Media Transfer Protocol For Wireless Digital Still Cameras, Microsoft PressPass.
★
Free software with PTP support