ISO 15740:2013

INTERNATIONAL ISO
STANDARD 15740
Third edition
2013-09-15
Photography — Electronic still
picture imaging — Picture transfer
protocol (PTP) for digital still
photography devices
Photographie — Imagerie des prises de vue électroniques —
Protocole de transfert d’images (PTP) pour les appareils
photographiques électroniques numériques
Reference number
ISO 15740:2013(E)
©
ISO 2013

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ISO 15740:2013(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO 2013
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
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ISO 15740:2013(E)

Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Digital still photography device model . 5
4.1 Overview . 5
4.2 Baseline requirements . 6
5 Data format specification . 6
5.1 General format . 6
5.2 Data types . 7
5.3 Simple types . 9
5.4 Arrays .11
5.5 Data sets . .12
6 Image and data object formats .21
6.1 Object usage .21
6.2 Thumbnail formats .22
6.3 ObjectFormatCodes .23
6.4 Object format version identification .23
6.5 Data object association .24
7 Transport requirements .26
7.1 Disconnection events.26
7.2 Reliable, error-free channel .27
7.3 Asynchronous event support .27
7.4 Device discovery and enumeration .27
7.5 Specific transports .27
8 Persistent storage .27
8.1 StorageID .27
8.2 Data object referencing .28
8.3 Receiver object placement .29
9 Communication protocol .30
9.1 Device roles .30
9.2 Sessions .30
9.3 Transactions .30
9.4 Operation flow .33
9.5 Vendor extensions .33
10 Operations .35
10.1 Operation overview .35
10.2 Operation parameters .35
10.3 OperationCode format .35
10.4 OperationCode summary .35
10.5 Operation descriptions .35
11 Responses .60
11.1 ResponseCode format .60
11.2 ResponseCode summary .60
11.3 Response descriptions .61
12 Events
.66
12.1 Event usage .66
12.2 Event types .66
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ISO 15740:2013(E)

12.3 Event data set .66
12.4 EventCode format .67
12.5 EventCode summary .67
12.6 Event descriptions .67
13 Device properties .71
13.1 Device property usage .71
13.2 Values of a device property .71
13.3 Device property management requirements .72
13.4 Device property identification .72
13.5 Device property descriptions .76
14 Streaming (PTP v1.1 only) .92
14.1 Streaming overview .92
14.2 Stream transfer .92
14.3 Multiplexing .92
14.4 Discovering and configuring stream capabilities .93
14.5 Data transfer mechanism .93
14.6 Packet layout .94
14.7 Frame layout .95
14.8 Enumerating supported streams .95
14.9 Retrieving stream information.95
15 Conformance section .95
Annex A (informative) Optional device features .98
Annex B (normative) Object referencing and format codes .100
Annex C (informative) Operation flow example scenarios .102
Annex D (informative) Filesystem implementation examples .106
Annex E (informative) Reference to OSI model .109
Annex F (informative) SendObject implementation example .112
Bibliography .115
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ISO 15740:2013(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directives
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received. www.iso.org/patents
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
The committee responsible for this document is ISO/TC 42, Photography.
This third edition cancels and replaces the second edition (ISO 15740:2008), of which it constitutes a
minor revision with the following changes:
— as the vendor extension ID registry formerly maintained by the I3A has been transferred to another
organization, term 3.21 (I3A) was removed and the remaining terms renumbered;
— in 9.5.1, the fourth and fifth sentences were amended and combined to reflect that a new organization
assigns and maintains VendorExtensionIDs.
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ISO 15740:2013(E)

Introduction
This third edition of ISO 15740 (hereinafter designated PTP v1.1) provides optional support for new
increased performance and compatibility. All new constructs are fully backward compatible with the
first edition (hereinafter designated PTP v1.0) and are optional. See 5.5.2 for standard version.
For the purposes of this International Standard, digital still photography devices (DSPDs) are defined
as devices with persistent storage which capture a digital two-dimensional image at a discrete point in
time. Most DSPDs include interfaces that can be used to connect to a host computer or other imaging
device, such as a printer. A number of high speed interface transports has been developed, including
USB, TCP/IP and IEEE 1394 (FireWire). This International Standard is designed to provide requirements
for communicating with DSPDs. This includes communications with any type of device, including
host computers, direct printers and other DSPDs over a suitable transport. The requirements include
standard image referencing behaviour, operations, responses, events, device properties, data sets and
data formats to ensure interoperability. This International Standard also provides optional operations
and formats, as well as extension mechanisms.
This International Standard specifies the following:
— behaviour requirements for DSPDs; this includes the baseline features a device needs to support in
order to provide interoperability over conforming transports;
— functional requirements needed by a transport to facilitate the creation of a transport-dependent
implementation specification that conforms to this International Standard;
— a high-level protocol for communicating with and between DSPDs consisting of operation, data and
response phases;
— sets of suggested data codes and their usages including
— OperationCodes,
— ResponseCodes,
— ObjectFormatCodes,
— DevicePropCodes,
— EventCodes,
— required data sets and their usages,
— a means of describing data object associations and filesystems and
— mechanisms for implementing extensibility.
This International Standard does not attempt to define any of the following:
— any sort of device discovery, enumeration or transport aggregation methods; implementation of this
functionality is left to the transports and the platforms upon which support for this International
Standard is implemented;
— an application programming interface; this is left to the platforms upon which support for this
International Standard is implemented.
This International Standard has been designed to appropriately support popular image formats used in
[15]
digital still cameras, including the Exif and TIFF/EP formats defined in ISO 12234-1 and ISO 12234-2,
as well as the Design Rule for Camera Filesystem (DCF) and the Digital Print Order Format (DPOF).
The technical content of this International Standard is closely related to PIMA 15740:2000. The main
difference is that PIMA 15740:2000 includes an informative annex describing a USB implementation of
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ISO 15740:2013(E)

ISO 15740. This information is not included in this International Standard, which instead references the
USB still device class document developed by the Device Working Group of the USB Implementers Forum.
PTP v1.1 provides optional support for new increased performance and compatibility. All new constructs
are fully backward compatible with PTP v1.0 and are optional.
— Performance Enhancements:
— Support for retrieval of ObjectHandles in enumerated chunks, via specification of three new
optional operations and a new response code. This may reduce long response times for some
initiators that possess large numbers of objects.
— Support for optional arbitrary resizing prior to image transmission via specification of a new
operation GetResizedImageObject. In PTP v1.0, image sizes might be requested in full-resolution
or thumbnail size only.
— Support for arrays of data sets. This can be used to reduce the number of required transactions
necessary for device characterization from being a function of the number of objects on the
device to one.
— An optional fast file characterization operation called GetFilesystemManifest that exploits data
set arrays to request, in a single transaction, only the minimum data required to characterize
a typical filesystem. Many initiators, particularly in printing scenarios, are interested in fast
filesystem characterization for access to a specifically named file in a particular place. This
capability can significantly improve end-user workflow latency. This single operation replaces
the typical series of many GetObjectInfo requests with a binary filesystem manifest. This
manifest is defined as a simple array of a subset of the standard ObjectInfo data set called the
ObjectFilesystemInfo data set. This operation replaces the need for many GetObjectInfo calls,
while also avoiding the need for responders to perform many internal file-opens on the fly, or
to cache ObjectInfo image data that is often held persistently only “inside” internal image files
(e.g. TIFF tags inside EXIF JPEGs), to quickly communicate only the fast filesystem information.
— Compatibility Enhancements:
— An optional mechanism to support multiple vendor extension sets. This is specified via the new
VendorExtensionMap data set, and two new optional operations that may be invoked outside of
a session (GetVendorExtensionMaps and GetVendorDeviceInfo).
— The optional fast file characterization method GetFilesystemManifest natively supports
extremely large objects, by requiring 8-bytes for object size (UINT64), as opposed to the
standard 4-bytes.
— A new standard ObjectFormatCode to support the Digital Negative file format (DNG).
— Feature Enhancement:
— An optional mechanism for handling streaming content. This is specified via the new StreamInfo
data set, as well as the supporting GetStreamInfo and GetStream operations, as well as some
optional new supporting DeviceProperties. This is described in a new Clause 14.
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INTERNATIONAL STANDARD ISO 15740:2013(E)
Photography — Electronic still picture imaging — Picture
transfer protocol (PTP) for digital still photography devices
1 Scope
This International Standard provides a common communication protocol for exchanging images with
and between digital still photography devices (DSPDs). This includes communication between DSPDs
and host computers, printers, other digital still devices, telecommunications kiosks and image storage
and display devices.
This protocol is transport- and platform-independent.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 8601, Data elements and interchange formats — Information interchange — Representation of
dates and times
ISO 12234-2, Electronic still-picture imaging — Removable memory — Part 2: TIFF/EP image data format
ISO/IEC 10646, Information technology — Universal Coded Character Set (UCS)
ISO/IEC 10918-1:1994, Information technology — Digital compression and coding of continuous-tone still
images: Requirements and guidelines
IEC 61966-2-1, Multimedia systems and equipment — Colour measurement and management — Part 2-1:
Colour management — Default RGB colour space — sRGB
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
album
end-user-created object used to logically group data objects according to some user-defined criteria
Note 1 to entry: An album might or might not be a physical folder in a filesystem. In this International Standard,
an album is a type of association.
3.2
association
logical construct used to expose a relationship between discrete objects
Note 1 to entry: Associations are used to indicate that separate data objects are related. Associations are
represented like folders, and can be nested using a standard branched hierarchical tree structure.
EXAMPLE A time sequence, or user-defined groupings by content or capture session.
3.3
connection
transport-provided mechanism for establishing paths for transferring data between devices
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ISO 15740:2013(E)

3.4
datacode
16-bit unsigned integer whose Most Significant Nibble (4 bits) is used to indicate the category of code
and whether the code value is standard or vendor-extended
3.5
data object
image or other type of data that typically exists in persistent storage of a DSPD or other device
3.6
dataset
transport-independent collection of one or more individual data items with known interpretations
Note 1 to entry: Data sets are not necessarily opaque nor atomic to transport implementations.
3.7
Design Rule for Camera Filesystem
DCF
standard convention for camera filesystems which specifies the file format, foldering and naming
conventions in order to promote file interoperability between conforming digital photography devices
3.8
device discovery
act of determining the set of all devices present on a particular transport or platform that are physically
or logically accessible
3.9
digital still photography device
DSPD
device with persistent storage which captures a two-dimensional digital still image
3.10
Digital Print Order Format
DPOF
standardized ASCII file stored on removable media along with the image files that indicates how many
copies of which images should be printed
Note 1 to entry: DPOF also allows index prints, cropping, and text overlays to be specified.
3.11
enumeration
act of creating an ordered increasing numerical list that contains one representative element for each
member of a set
3.12
Exif/JPEG
compressed file format for digital cameras in which the images are compressed using the baseline JPEG
standard described in ISO 12234-2
Note 1 to entry: In Exif, metadata and thumbnail images are stored using TIFF tags within an application segment
at the beginning of the JPEG file.
3.13
folder
optional sub-structure in a hierarchical storage area that can contain data objects
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3.14
FlashPix
image file format, defined in FlashPix Format Specification, using a structured storage file containing
metadata and a tiled, hierarchical image representation
Note 1 to entry: The tiles in a FlashPix image are normally baseline JPEG images, and individual image tiles of a
particular resolution can be easily accessed for rapid display and editing.
3.15
IEEE 1394
high-speed serial bus standardized by the IEEE (Institute of Electrical and Electronics Engineers)
currently having clock rates of 100, 200 and 400 Mbits/s
Note 1 to entry: IEEE 1394 is often referred to as FireWire.
...