OpenRaster

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OpenRaster
Filename extension .ora
Internet media type image/openraster[1]
Type of format Layered raster graphics
Extended from OpenDocument
Open format? Yes
Website freedesktop.org/wiki/Specifications/OpenRaster

OpenRaster is a file format proposed for the common exchange of layered images between raster graphics editors. It is meant as a replacement for later versions of the Adobe PSD format. OpenRaster is still in development and so far is supported by a few programs.[2] The default file extension for OpenRaster files is ".ora".

Background[edit]

The Adobe Photoshop PSD file format was widely used as a cross-application file format for layered images. Adobe allowed this by releasing the format's specifications publicly. In 2006 Adobe changed this license to only grant access to and use of the specifications and documentation "for the purposes of internally developing Developer Programs in connection with Adobe Software products and incorporating portions or all of the Sample Code into Developer Programs."[3] In response to these restrictions, the OpenRaster format was proposed by KDE and Krita developers Boudewijn Rempt[4] and Cyrille Berger[5] at the first Libre Graphics Meeting at Lyon, France in the spring of 2006 and is drawn from the Open Document Format.[6]

Requirements[edit]

Following features should be present:

General[edit]

  • full freely available documentation
  • OpenDocument type of file format (archive with multiple files inside)
  • extensible, but private undocumented extensions should be excluded, any extension should be added to the spec and documentation of the file format
  • applications are not expected to support all features of the file format, but when manipulating the file they should not lose any information they cannot handle

Metadata[edit]

Layers[edit]

  • storage of multiple layers
  • storage of each layer's coordinates
  • storage of blending (compositing) options for each layer
  • storage of adjustment layers
  • storage of layer effects
  • groups of layers
  • color information – profile, colorspace

Other[edit]

  • storage of paths, clipping paths and text on path
  • selections and masks
  • embedding documents within OpenDocument frameworks
  • support undo, history of commands and actions (like PSD)

Proposals and extensions[edit]

  • Palette
  • Embed Fonts (Proposal to extension)
  • Multiple pages
  • Animation support using multiple pages and a timer (like PSD)

Challenges[edit]

According to the draft specification (as of October 2010), a major challenge for a cross-application format is that because not all of the features are available in all the programs, an image won't be displayed the same way in different applications, especially for adjustment/filters layers. And "viewer" applications like Inkscape or Scribus[7] won't have any implementation at all of those features.

A likely work-around is the optional storage of a redundant extra layer containing the fully rendered pixel data as seen after all image processing, or possibly a lower-resolution snapshot of it suitable for previewing and thumbnailing.

Different implementations levels might be defined, like, tiny, simple, small, normal, full and custom.

Application support[edit]

OpenRaster has limited support in a few graphics programs and among these its cross-application use is not seamless.[citation needed]

Application Status
DrawPile Basic (development version)[8]
GIMP Fundamental support with version 2.8.[9]
Krita Supported.[10]
LazPaint Reading since version 5.0 and writing since 5.2[11]
MyPaint Default working file format.[12]
Nathive Default format since 0.908.[13]
Pinta Supported starting with version 0.4.[14]
XnView Supported starting with version 1.98.1 [15]
Scribus Supported starting with version 1.5 [16]

See also[edit]

References[edit]

  1. ^ http://freedesktop.org/wiki/Specifications/OpenRaster/DesktopIntegration
  2. ^ OpenRaster Specifications Create Project OpenRaster wiki. Accessed 2010-03-26.
  3. ^ "Adobe Photoshop CS4 SDK License Agreement" Adobe.com. Developer Connection - Developer Resources. Retrieved 2009-10-12.
  4. ^ http://valdyas.org/fading/index.cgi/software/krita/openraster.html
  5. ^ http://blog.cberger.net/2006/06/20/why-openraster-is-needed/
  6. ^ "Debate arises over an open raster graphics format" Nathan Willis, Linux.com Archive. July 07, 2006. Retrieved 2010-03-26.
  7. ^ Scribus development branch 1.5 can import OpenRaster files since 26 March 2014
  8. ^ SCM Repositories - drawpile Sourceforge Drawpile project. June 14, 2009. Accessed 2010-03-26.
  9. ^ GIMP - Release Notes for GIMP 2.8 Accessed 2012-05-03.
  10. ^ Krita/OpenRaster status KOffice Developers Wiki. KOffice.org. Accessed 2010-03-26.
  11. ^ LazPaint thread, 2013-02-27
  12. ^ "MyPaint/OpenRaster News" Alexandre Prokoudine, Prokoudine.info - blog. June 8th, 2009.
  13. ^ "Nathive 0.908 release notes" Nathive website documentation
  14. ^ "Pinta - Version 0.4 Release Notes". 2010-07-06. 
  15. ^ "XnView release notes" XnView forum announcement
  16. ^ "Scribus mailing list" Scribus mailing list announcement

External links[edit]