gegl commandline

In addition to installing a library, GEGL also installs gegl - a binary/program that permits doing image processing from the commandline as well as an aid during development of GEGL operations.

Some examples:

Render a composition to a PNG file, the composition can be in GEGLs XML format or the one-liner friendly terser gegl-chain format.

$ gegl composition -o composition.png

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/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. After chaining a new op in properties can be set
with property=value pairs as subsequent arguments.