gegl
GEGL provides a commandline tool called gegl, for working with the XML data model from file, stdin or the commandline. It can display the result of processing the layer tree or save it to file.
Some examples:
Render a composition to a PNG file:
$ gegl composition.xml -o composition.png
Using gegl with png’s passing through stdin/stdout piping.
$ cat input.png | gegl -o - -x "<gegl>
<tree>
<node class='invert'/>
<node class='scale' x='0.5' y='0.5'/>
<node class='png-load' path='-'/></tree></gegl>" > output.png
The latest development version is available in the gegl repository in GNOME git.
gegl usage
The following is the usage information of the gegl binary, this documentation might not be complete.
usage: /home/pippin/src/gegl/bin/.libs/lt-gegl [options] <file | -- [op [op] ..]>
Options:
-h, --help this help information
--list-all list all known operations
--exists return 0 if the operation(s) exist
--properties output the properties (name, type, description) of the operation
-i, --file read xml from named file
-x, --xml use xml provided in next argument
--dot output a graphviz graph description
-o, --output output generated image to named file, type based
on extension.
-p increment frame counters of various elements when
processing is done.
-s scale, --scale scale scale output dimensions by this factor.
-X output the XML that was read in
-v, --verbose print diagnostics while running
All parameters following -- are considered ops to be chained together
into a small composition instead of using an xml file, this allows for
easy testing of filters. Be aware that the default value will be used
for all properties.