ISO 15740:2005

INTERNATIONAL ISO
STANDARD 15740
First edition
2005-08-15
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 2005
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ii © ISO 2005 – All rights reserved

Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Digital Still Photography Device Model. 6
5 Data Format Specification . 7
6 Image and Data Object Formats. 19
7 Transport requirements . 25
8 Persistent Storage . 25
9 Communication Protocol . 28
10 Operations . 31
11 Responses. 51
12 Events . 57
13 Device properties. 63
14 Conformance Section. 79
Annex A (informative) Optional Device Features. 81
Annex B (normative) Object referencing and format codes. 83
Annex C (informative) Operation flow example scenarios. 85
Annex D (informative) Filesystem implementation examples . 89
Annex E (informative) Reference to OSI Model. 91
Annex F (informative) SendObject Implementation Example. 94
Bibliography . 98

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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 15740 was prepared by Technical Committee ISO/TC 42, Photography.
iv © ISO 2005 – All rights reserved

Introduction
For the purposes of this International Standard, digital still photography devices (DSPDs) are defined as
devices with persistent storage that 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, datasets, 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 enable 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 datasets and their usages
 a means of describing data object associations and filesystems
 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 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
ISO 15740. This information is not included in ISO 15740, which instead references the USB still device class
document developed by the Device Working Group of the USB Implementers Forum.
vi © ISO 2005 – All rights reserved

INTERNATIONAL STANDARD ISO 15740:2005(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 referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 8601:2004, Data elements and interchange formats — Information interchange — Representation of
dates and times
ISO 12234-1:2001, Electronic still-picture imaging — Removable memory — Part 1: Basic removable-memory
module
ISO 12234-2:2001, Electronic still-picture imaging — Removable memory — Part 2: TIFF/EP image data
format
ISO/IEC 10646-1:1993, Information technology — Universal Multiple-Octet Coded Character Set (UCS) —
Part 1: Architecture and Basic Multilingual Plane
ISO/IEC 10918-1:1994, Information technology — Digital compression and coding of continuous-tone still
images: Requirements and guidelines
IEC 61966-2-1:1999, 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 An album may or may not be a physical folder in a filesystem. In this International Standard, an album is a
type of association.
3.2
Application Programming Interface
API
high-level functional description of a software interface
NOTE An API is typically language-dependent.
3.3
association
logical construct used to expose a relationship between discrete objects
NOTE Associations are used to indicate that separate data objects are related. Associations are represented like
folders, and may be nested using a standard branched hierarchical tree structure.
EXAMPLE A time sequence, or user-defined groupings by content or capture session.
3.4
connection
transport-provided mechanism for establishing paths for transferring data between devices
3.5
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
3.6
data object
image or other type of data that typically exists in persistent storage of a DSPD or other device
3.7
dataset
transport-independent collection of one or more individual data items with known interpretations
NOTE Data sets are not necessarily opaque nor atomic to transport implementations.
3.8
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
3.9
device discovery
act of determining the set of all devices present on a particular transport or platform that are physically or
logically accessible
2 © ISO 2005 – All rights reserved

3.10
Digital Still Photography Device
DSPD
device with persistent storage that captures a two-dimensional digital still image
3.11
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 DPOF also allows index prints, cropping, and text overlays to be specified.
3.12
enumeration
act of creating an ordered increasing numerical list that contains one representative element for each member
of a set
3.13
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 In Exif, metadata and thumbnail, images are stored using TIFF tags within an application segment at the
beginning of the JPEG file.
3.14
folder
optional sub-structure in a hierarchical storage area that can contain data objects
3.15
FlashPix
image file format, defined in FlashPix Format Specification, using a structured storage file containing metadata
and a tiled, hierarchical image representation
NOTE The tiles in
...