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.[3] The default file extension for OpenRaster files is ".ora".

OpenRaster
Filename extension
.ora
Internet media type
image/openraster[1]
Latest release
0.0.5 (draft)[2]
Type of formatLayered raster graphics
Extended fromOpenDocument
Open format?Yes
WebsiteOpenRaster Specification at openraster.org

Background

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."[4] In response to these restrictions, the OpenRaster format was proposed by KDE and Krita developers Boudewijn Rempt[5] and Cyrille Berger[6] at the first Libre Graphics Meeting at Lyon, France in the spring of 2006 and is drawn from the Open Document Format.[7]

Requirements

Following features should be present:

General
  • 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

Layers
  • 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

See[8]

  • 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
  • palette
  • embedded fonts (proposal to extension)
  • multiple pages
  • animation support using multiple pages and a timer (like PSD)

Challenges

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.

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

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

Application Baseline SVG
DrawPile Supported[9] Yes
Chasys Draw IES Supported[10] Yes
GIMP Basic support since version 2.8[11] No
Inkscape Unsupported
Krita Supported[12][13] No
LazPaint Reading since version 5.0 and writing since 5.2[14] Yes
MyPaint Default working file format[15] Yes
Nathive Default format since 0.908[16]
Pinta Supported starting with version 0.4[17] No
XnView Supported through a user-made plugin[18]
Scribus Supported starting with version 1.5[19] No
ImageMagick Supported starting with version 7.0.10-26[20] Yes
Paint.net Supported through a user-made plugin[21] No

See also

References
  1. "OpenRaster Desktop Integration". openraster.org. Retrieved 2016-12-19.
  2. "OpenRaster Specification (Draft)". openraster.org. Retrieved 2016-12-19.
  3. "OpenRaster Specification". openraster.org. Retrieved 2016-12-19.
  4. "Adobe Photoshop CS4 SDK License Agreement" Adobe.com. Developer Connection - Developer Resources. Retrieved 2009-10-12.
  5. Rempt, Boudewijn (2006-06-20). "OpenRaster". valdyas.org. Fading Memories. Archived from the original on 2013-04-16. Retrieved 2016-12-19.
  6. Berger, Cyrille (June 20, 2006). "Why OpenRaster is needed ?". blog.cberger.net. Retrieved 2016-12-19.
  7. "Debate arises over an open raster graphics format" Nathan Willis, Linux.com Archive. July 07, 2006. Retrieved 2010-03-26.
  8. "Proposals and Application Specific Extensions — Open Raster Specification version 0.05". www.openraster.org.
  9. Drawpile Drawpile project. Sept 3, 2018. Accessed 2018-09-03.
  10. Chasys Draw IES Help - File Formats - Other Image Files. Dec 12, 2018. Accessed 2018-12-12.
  11. GIMP - Release Notes for GIMP 2.8 Accessed 2012-05-03.
  12. "Krita/OpenRaster status". community.kde.org. Retrieved 2016-12-19.
  13. "*.ora - Krita Documentation". docs.krita.org. Retrieved 2016-12-19.
  14. LazPaint thread, 2013-02-27
  15. "MyPaint/OpenRaster News" Archived 2016-03-08 at the Wayback Machine Alexandre Prokoudine, Prokoudine.info - blog. June 8th, 2009.
  16. "Nathive 0.908 release notes" Nathive website documentation
  17. "Pinta - Version 0.4 Release Notes". 2010-07-06. Archived from the original on 2010-07-08.
  18. XnView Plugins
  19. "Scribus mailing list" Scribus mailing list announcement
  20. ImageMagick Changelog
  21. "OpenRaster Filetype" by user Zagna
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