View source for GEGL

==Design==
GEGL is modelled after a [[directed acyclic graph]], where each ''node'' represents an image ''operation'' (called "operators" or "ops"), and each ''edge'' represents an ''image''. Operations can in general take several input images and give several output images, which corresponds to having several incoming edges (images) and several outgoing edges (images) at a given node (operation). The system uses an on-demand model, doing work only as required. This allows features such as having very quick previews while editing, and once the user has finished making changes, GEGL will repeat the same operations in full resolution for the final image in the background.

===Operations===
An operation (op) is a node within a GEGL graph responsible for one action; ops can be:
* simple, such as "add" (taking two inputs) or "premultiply by alpha" (taking one input)
* complex, such as colorspace conversions

GEGL also has a notion of meta operations, where one operation can be constructed from other operations (e.g. ''unsharp mask'' is a combination of ''add'', ''multiply'', ''subtract'' and ''gaussian blur'' ops).

===babl===
babl, a support library for GEGL, provides a generic way to deal with [[color-space]] conversions;<ref>[http://gegl.org/babl/ babl website]</ref>
babl operates abstracting the fundamental color operations so that GEGL need not be aware of them. Through babl, GEGL provides an optimized and powerful (optionally with [[SIMD]] support) treatment of arbitrary color data; this enables dependent applications to efficiently support a wide range of color spaces (from 8-bit [[RGB color model|RGB]] to full [[floating point]] [[CMYK color model|CMYK]]) with minimal extra application code.