gegl command-line
In addition to installing a library, GEGL also installs gegl - a binary/program that permits doing image processing from the command-line as well as an aid during development of GEGL operations. GEGL behaviour can be modified at runtime by setting appropriate environment variables.
- Some examples
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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.xml -o composition.png
gegl usage
The following is the usage information of the gegl binary, this documentation might not be complete.
usage: /build/gegl-vNNnnV/gegl-0.4.42/obj-x86_64-linux-gnu/bin/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
--info output information about the operation:
name, description, properties details.
-i, --file read xml from named file
-x, --xml use xml provided in next argument
-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.