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.^[1] The default file extension for OpenRaster files is ".ora".

Background

For many years the Adobe Photoshop PSD file format was used as a cross-application file format for layered images. Adobe allowed this by releasing the format's specifications publicly. However, 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."^[2] In response to these restrictions, the OpenRaster format was proposed at the first Libre Graphics Meeting at Lyon, France in the spring of 2006 and is drawn from the Open Document Format.^[3]

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 aren't expected to support all features of the file format, but when manipulating the file they shouldn't lose any information they can't handle

Metadata

• storage of metadata using {XMP - Dublin Core - IPTC} tags
• possibility of storing metadata tags per layer
• storage of Exif tags
• all text data in Unicode (UTF-8 or UTF-16)

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

• storage of paths, clipping paths, text on path
• selections, masks
• embedding documents within OpenDocument framework
• support undo/history of commands/actions like PSD do

Proposals and extensions

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

Challenges

A major problem is that because all features aren't available in all the programs, image won't be displayed the same way in different applications, especially for adjustement/filters layers. And "viewer" apps like inkscape or scribus 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

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

Application	Status
MyPaint	Default working file format.[4]
GIMP	Planned[5] + external plug-in.[6]
Krita	Supported.[7]
DrawPile	Basic (development version)[8]
Nathive	Default format since 0.908.[9]
Pinta	Supported starting with version 0.4.[10]
XnView	Supported starting with version 1.98.1 [11]

See also

Free software portal

• Create Project
• FreeDesktop.org
• Libre Graphics Meeting
• free and open source software
• GIMP
• Krita
• FXG

References

1. ^ OpenRaster Specifications Create Project OpenRaster wiki. Accessed 2010-03-26.
2. ^ "Adobe Photoshop CS4 SDK License Agreement" Adobe.com. Developer Connection - Developer Resources. Retrieved 2009-10-12.
3. ^ "Debate arises over an open raster graphics format" Nathan Willis, Linux.com Archive. July 07, 2006. Retrieved 2010-03-26.
4. ^ "MyPaint/OpenRaster News" Alexandre Prokoudine, Prokoudine.info - blog. June 8th, 2009.
5. ^ pippin's website at gimp.org - OpenRaster
6. ^ [CREATE] Announcing oratools; with a GIMP plug-in for OpenRaster load/save Jon Nordby (September 2, 2009) Freedesktop.org CREATE mailing list archive. Accessed 2010-03-26.
7. ^ Krita/OpenRaster status KOffice Developers Wiki. KOffice.org. Accessed 2010-03-26.
8. ^ SCM Repositories - drawpile Sourceforge Drawpile project. June 14, 2009. Accessed 2010-03-26.
9. ^ "Nathive 0.908 release notes" Nathive website documentation
10. ^ "Pinta - Version 0.4 Release Notes". 2010-07-06. http://pinta-project.com/release/0.4. 
11. ^ "XnView release notes" XnView forum announcement

External links

• Specification website
• Create Project
• pippin's website at gimp.org - OpenRaster (archive)
• Integration of Gimp Openraster into mainline