PTP/IP, developed by FotoNation and first implemented in a round of Wi-Fi digital cameras by Nikon, Canon, and Eastman Kodak, allows data transfer over any IP-based network. For example, if the controlling software was running on a Smartphone with GPS functionality, it would be possible to add the GPS coordinates to an image's Exif data, at the time of image capture - even if the camera itself had no GPS functionality.Ī number of protocols have been developed that extend PTP. As described above, the storage objects of the camera's memory cards can be manipulated too.īy controlling a camera in this way it is possible to augment its capabilities. In addition to changing the camera's settings and operating mode, it is possible to receive a through-the-lens view using "Live View". Events raised by the camera, in response to specific actions performed by the host device, are sent back to the host via the USB asynchronous Interrupt endpoint. When interacting with the camera in this manner, it is expected that the USB endpoints are in (synchronous) Bulk Transfer Mode, for getting/setting virtually all the camera's features/properties (such as ISO, Aperture, Shutter speed and focus). As is the norm for PTP, the communication takes place over a USB connection. Many modern digital cameras from Canon and Nikon can be controlled via PTP from a USB host enabled computing device (Smartphone, PC or Arduino for example). But none of these are required as PTP abstracts from the underlying representation.īy contrast, if a camera is mounted via USB MSC, the physical file system and layout are exposed to the user. Images on digital cameras are generally stored as files on a mass storage device, such as a memory card, which is formatted with a file system, most commonly FAT12, FAT16 or FAT32, which may be laid out as per the Design rule for Camera File system (DCF) specification. However, it is designed to support existing standards, such as Exif, TIFF/EP, DCF, and DPOF, and is commonly implemented over the USB and FireWire transport layers. PTP does not specify a way for objects to be stored – it is a communication protocol. Key contributors to the standard included Tim Looney and Tim Whitcher ( Eastman Kodak Company) and Eran Steinberg ( Fotonation). PTP was originally standardized as PIMA 15470 in 2000, while it was developed by the IT10 committee. The term "Picture Transfer Protocol" and the acronym "PTP" were both coined by Steve Mann, summarizing work on the creation of a Linux-friendly way of transferring pictures to and from home-made wearable computers, at a time when most cameras required the use of Microsoft Windows or Mac OS device drivers to transfer their pictures to a computer. Until the standardization of PTP, digital camera vendors used different proprietary protocols for controlling digital cameras and transferring images to computers and other host devices. These objects can however have parents and siblings so that a file-system–like view of device contents can be created. While it is common to think of the objects that PTP handle as files, they are abstract entities identified solely by a 32-bit object ID. PTP specifies a way of creating, transferring and manipulating objects which are typically photographic images such as a JPEG file. USB PTP is a common alternative to the USB mass-storage device class (USB MSC), as a digital camera connection protocol. USB is the default network transport media for PTP devices. It is further standardized for USB by the USB Implementers Forum as the still image capture device class. The protocol has been standardized as ISO 15740. Picture Transfer Protocol ( PTP) is a 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. Tim Looney and Tim Whitcher ( Eastman Kodak Company), Eran Steinberg ( Fotonation), and others Protocol to transfer images from digital cameras to computers Picture Transfer Protocol Abbreviation
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