Overview
ISO 15740:2013 - Photography - Electronic still picture imaging - Picture Transfer Protocol (PTP) - defines a common, transport- and platform-independent communication protocol for exchanging images with and between digital still photography devices (DSPDs). Published as the third edition (PTP v1.1), the standard specifies interoperable mechanisms for image transfer, device discovery, object referencing and metadata handling between cameras, host computers, printers, kiosks and storage/display devices.
Keywords: ISO 15740, Picture Transfer Protocol, PTP, digital still photography devices, image transfer, device communication, interoperability.
Key technical topics and requirements
ISO 15740:2013 organizes protocol behavior and requirements across logical areas rather than providing low-level transport specifics. Major topics include:
- Data format specification - Definitions for data types, simple types, arrays and data sets used for communication and metadata.
- Image and data object formats - Rules for thumbnails, object format codes and object association to ensure consistent image referencing.
- Transport requirements - Guidance for reliable channels, asynchronous event support, device discovery and specific transport considerations (USB, TCP/IP, IEEE 1394 referenced).
- Persistent storage and object referencing - StorageIDs, data object referencing and receiver placement semantics for DSPDs.
- Communication protocol - Device roles, sessions, transactions and operation flow to manage commands and responses cleanly.
- Operations, responses and events - Formalized operation codes, response codes and event types to support predictable device behavior.
- Device properties and management - Standardized device property identification, values and property-management requirements.
- Streaming (PTP v1.1 only) - Optional high-performance streaming constructs, packet/frame layout and multiplexing for advanced devices.
- Conformance and vendor extensions - Rules for optional features, vendor extension registration and conformance testing.
Practical applications
ISO 15740:2013 enables reliable image exchange workflows across hardware and software ecosystems. Typical applications:
- Transferring photos from cameras to host computers and cloud gateways.
- Direct printing from cameras to networked/USB printers and kiosks.
- Inter-device image exchange between cameras, storage devices and display systems.
- Remote device control, metadata synchronization and event-driven image capture workflows.
- Implementing interoperable firmware and device drivers for camera manufacturers and accessory vendors.
Who should use this standard
- Camera and DSPD manufacturers (firmware and hardware design)
- Printer and kiosk vendors integrating direct image printing
- Software developers creating image-management, backup, or device-control applications
- Systems integrators building interoperable imaging solutions
- Test labs and compliance teams validating PTP conformance
Related standards and notes
ISO 15740 is maintained by ISO/TC 42 (Photography) and complements transport standards such as USB, TCP/IP and IEEE 1394 by defining the protocol semantics above the transport layer. PTP v1.1 remains backward compatible with earlier PTP versions while adding optional performance and streaming features.