SIST ISO 15740:2014 adopts ISO 15740:2013 and specifies the Picture Transfer Protocol (PTP) for electronic still picture imaging. The standard defines a common, transport- and platform-independent communication protocol for exchanging images and related metadata between digital still photography devices (DSPDs) and other systems - including host computers, printers, kiosks, storage and display devices. This third edition (PTP v1.1) updates device/operation semantics and adds optional streaming capabilities.
Key topics and technical requirements
The standard is organized to cover the full protocol lifecycle and implementation requirements:
- Data format specification - primitive data types, arrays and structured data sets for PTP messaging.
- Image and data object formats - object usage, thumbnail formats, ObjectFormatCodes and associations.
- Transport requirements - device discovery, reliable error-free channels, asynchronous event support and disconnect handling.
- Persistent storage and referencing - StorageID, object referencing and receiver placement rules.
- Communication protocol mechanics - device roles, sessions, transactions, operation flow and vendor extension management.
- Operations, responses and events - comprehensive operation codes, response codes and event definitions used to control devices and report status.
- Device properties management - property identification, value semantics and configuration/management requirements.
- Streaming (PTP v1.1 only) - optional support for stream discovery, configuration, packet/frame layout and multiplexing for higher-performance transfers or live-view streams.
- Conformance and implementation guidance - conformance tests and informative annexes including filesystem examples, operation flow scenarios and OSI model references.
Practical applications
ISO 15740 / PTP is designed for real-world interoperability in digital photography ecosystems:
- Transfer images and metadata from cameras to host computers, printers and photo kiosks.
- Enable direct printing, remote device control, metadata exchange and thumbnail retrieval across heterogeneous devices.
- Support for image kiosks, storage appliances and display devices where reliable, standardized object transfer and discovery are required.
- Optional streaming enables high-throughput or live-view use cases in camera-to-host workflows.
Who should use this standard
- Camera and DSPD manufacturers implementing firmware and device control interfaces.
- Software developers building photo-management, editing or capture applications.
- Peripheral vendors (printers, kiosks, storage/display device OEMs) integrating standardized image transfer.
- System integrators and firmware engineers needing a transport-independent protocol for device-to-device image exchange.
Related standards and notes
- This document is the third edition of ISO 15740 (PTP v1.1). It is maintained under ISO/TC 42 (Photography).
- The protocol is intentionally transport-agnostic - implementers commonly map PTP to transports such as USB, TCP/IP or wireless links depending on product requirements.
Keywords: Picture Transfer Protocol, PTP, ISO 15740, electronic still picture imaging, digital still photography devices, image transfer protocol, device discovery, metadata, streaming, device properties.