PictBridge is an industry standard introduced in 2003 from the Camera & Imaging Products Association

Camera & Imaging Products Association

, is a Japan-based organization set up in July 2002 to deal with technologies related to photography. Its members are engaged with the production of film-based and digital cameras, and other related equipment....

 (CIPA) for direct printing. It allows images to be printed directly from digital camera

Digital camera

A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...

s to a printer

Computer printer

In computing, a printer is a peripheral which produces a text or graphics of documents stored in electronic form, usually on physical print media such as paper or transparencies. Many printers are primarily used as local peripherals, and are attached by a printer cable or, in most new printers, a...

, without having to connect the camera to a computer. Its formal name is “Standard of Camera & Imaging Products Association CIPA DC-001 — 2003 Digital Solutions for Imaging Devices”. CIPA DC-001-2003 Rev. 2.0 has been published in 2007.

PictBridge is typically implemented using Universal Serial Bus

Universal Serial Bus

USB is an industry standard developed in the mid-1990s that defines the cables, connectors and protocols used in a bus for connection, communication and power supply between computers and electronic devices....

 ports and the USB protocol. PictBridge-capable printers typically have a USB Type A receptacle which is then connected by cable to the USB port of a PictBridge-capable digital camera (typically a Type Mini-B). The user selects the images on the camera, which the printer retrieves and prints.

Proprietary ownership

PictBridge arguably does not qualify as an open standard

Open standard

An open standard is a standard that is publicly available and has various rights to use associated with it, and may also have various properties of how it was designed . There is no single definition and interpretations vary with usage....

, as the specification can only be obtained from CIPA after agreement not to disclose any information from the specification to others (section 2.2 of the agreement).
In practice this means that PictBridge cannot be implemented as free software

Free software

Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...

 or open source

Open source

The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...

 software other than by reverse-engineering the protocol (perhaps aided by the white paper that CIPA provides), if publishing source code of an implementation of the PictBridge standard is considered to count as “disclosing information” from the specification.

A printer may implement similar functions to a PictBridge printer without the non-disclosure agreement by treating the camera’s memory as a USB mass storage device

USB mass storage device class

The USB mass storage device class, otherwise known as USB MSC or UMS, is a protocol that allows a Universal Serial Bus device to become accessible to a host computing device, to enable file transfers between the two...

, although the user interface for image selection would necessarily be on the printer rather than the camera in this case.