What does GEGL graph do ?

[rich2005]

GIMP Version: 2.10
Operating System: Windows
GIMP Experience: Intermediate Level

List any relevant plug-ins or scripts:
GEGL graph

---

I do not really want to disrupt the Learn GEGL thread so:

mackenzieh wrote

I'm curious as to what this plugin does.

see: viewtopic.php?f=10&t=19463#p265540

The GEGL graph in Filters -> Generic lets the user run GEGL operations interactively. Those with a 'G' in the menus.

What is the advantage? Why not use the filters in the menus ?

The GEGL operations can be chained together and parameters adjusted without 'undoing' previous work.
A trivial example, posterize an image, followed by the very nice GEGL waterpixels then the illusion filter.
If I use a chain of operations like this.

Code:

posterize
    levels=4

waterpixels
    size=32
    smoothness=1
    regularization=0

illusion
    division=8
    illusion-type=type1


I can adjust any of the values for any parameter (within the scope of the filter) in the GEGL graph and see the result. No need to undo anything to go back.

very quick example as an animation. https://i.imgur.com/XtP5rfk.mp4

[racer-x]

Interesting. I guess this will replace script making for many instances. Just make your own filter combinations and save the presets.

[rich2005]

Interesting. I guess this will replace script making for many instances. Just make your own filter combinations and save the presets.

Yes. Not impossible to script GEGL operations with Gimp 2.10 there are examples somewhere (but not easy). So you could make a collection of "boilerplate" text files for specific tasks.

or as you say, save as a preset. (a blank without all that commented text is a good start )

The place for GEGL filters and syntax is https://gegl.org/operations/

[cli345]

Pleased with your intervention : very good introduction (I've added a link to here at start of my thread).

[mackenzieh]

It is interesting to see it in action. I'm glad you posted an example because I had no clue what the plugin did.

[teapot]

Thank you for the explanation rich2005 as I was also wondering what was going on.

[contrast_]

Try this

Code:


noise-reduction iterations=6
median-blur percentile=40 alpha-percentile=1

gaussian-blur #stays locked at 0.50 in default. Never changes.

emboss  type=bumpmap azimuth=30  elevation=40 depth=1                   

median-blur radius=4 percentile=900 alpha-percentile=90 high-precision=yes



opacity value=2

#repaste this to make more bevely


noise-reduction iterations=6


median-blur percentile=40 alpha-percentile=1

gaussian-blur #stays locked at 0.50 in default. Never changes.

emboss  type=bumpmap azimuth=30  elevation=40 depth=1                   

median-blur radius=5 percentile=900 alpha-percentile=90 high-precision=yes



opacity value=2

#repaste this to make more bevely


#final effects

dropshadow radius=1 x=2 y=0.6 grow-radius=1  opacity=1.1


bloom threshold=-35



dropshadow x=7.3 y=7.3 grow-radius=1


[contrast_]

I've been doing this for about a year. I have code designated for small, medium, large and very large text.

Code:

gegl:rotate degrees=0  sampler=lohalo

gegl:color-overlay value=#00f525

gegl:dropshadow x=0.00  y=0.00 radius=0.00 grow-shape=circle grow-radius=7 opacity=1 color=#000000

gegl:dropshadow x=0.00  y=0 radius=0.00 grow-shape=circle grow-radius=5 opacity=1 color=#ffffff

gegl:dropshadow opacity=1.9 radius=1.6 x=-1.8 y=2.8



[contrast_]

This is a specialty bevel with a custom image overlay from pattern monster.

Code:

gegl:rotate degrees=0.0  sampler=lohalo

gegl:color-overlay value=#ffec00


median-blur percentile=50 alpha-percentile=2

gaussian-blur #stays locked at 0.50 in default. Never changes.

emboss  type=bumpmap azimuth=70  elevation=40 depth=3                   

median-blur radius=10 percentile=100 alpha-percentile=80 high-precision=yes

multiply aux=[gegl:layer src=PUT_YOUR_FILE_HERE.png]
t
opacity value=2
gegl:gray



dropshadow opacity=0.5 x=4 y=2


dropshadow opacity=0.5 x=4 y=2


[mahvin]

Very nice results, Contrast. Thank you for sharing!

[contrast_]

yes and there is a lot more. I do not want to brag but I am a "GEGL Wizard" I want GEGL to put an end to the legacy engine.

Here is stained glass in GEGL

Code:

#stained_glass
id=1

noise-spread amount-y=96 amount-x=46 seed=33
oilify mask-radius=1 exponent=3 intensities=115
noise-reduction iterations=2


gimp:layer-mode layer-mode=normal  opacity=0.40 aux=[ ref=1 gaussian-blur std-dev-x=2  std-dev-y=2  ]
bloom threshold=80

[contrast_]

Code:


gimp:desaturate
edge-neon amount=0.65

id=1

gimp:layer-mode layer-mode=hardlight  aux=[ ref=1 b gaussian-blur std-dev-y=5 std-dev-x=5   ]
gimp:layer-mode layer-mode=behind opacity=0.14  aux=[ ref=1 b gaussian-blur std-dev-y=33.00 std-dev-x=53.00 gaussian-blur std-dev-y=113.00 std-dev-x=66.00   ]
gimp:layer-mode layer-mode=hardlight  aux=[ ref=1  ]







id=2
gimp:layer-mode layer-mode=normal  aux=[ ref=2 color-to-alpha color=#000000 ]
color-to-alpha color=#000000 transparency-threshold=0.09
bloom radius=6
gaussian-blur std-dev-y=2.5 std-dev-x=2.5


median-blur neighborhood=diamond radius=2 high-precision=true alpha-percentile=1

id=3

gimp:layer-mode layer-mode=normal opacity=0.25  aux=[ ref=3 bloom limit-exposure=true ]

[contrast_]

Gimp's blend modes control the color

Code:

simplex-noise scale=20 iterations=1 seed=2949

lens-blur radius=0.52 highlight-factor=0.531

softglow glow-radius=0.190 brightness=4.251 sharpness=0.503

median-blur radius=2. percentile=100 alpha-percentile=10 neighborhood=diamond

bloom threshold=77

lens-blur radius=0.50 highlight-factor=0.931

[contrast_]

Another Bevel FIlter

Code:

`gegl:rotate degrees=0 sampler=lohalo

gegl:color-overlay value=#00d8ff

median-blur percentile=40 alpha-percentile=2

gaussian-blur #stays locked at 0.50 in default. Never changes.

emboss type=bumpmap azimuth=35 elevation=40 depth=3

median-blur radius=10 percentile=080 alpha-percentile=60 high-precision=yes

opacity value=1.5

dropshadow x=2.6 y=2.6 opacity=1`

Code:


noise-reduction iterations=6
median-blur percentile=40 alpha-percentile=1

gaussian-blur #stays locked at 0.50 in default. Never changes.

emboss  type=bumpmap azimuth=30  elevation=40 depth=1                   

median-blur radius=4 percentile=900 alpha-percentile=90 high-precision=yes



opacity value=2



noise-reduction iterations=6
median-blur percentile=40 alpha-percentile=1

gaussian-blur #stays locked at 0.50 in default. Never changes.

emboss  type=bumpmap azimuth=30  elevation=40 depth=1                   

median-blur radius=5 percentile=900 alpha-percentile=90 high-precision=yes



opacity value=2




dropshadow radius=2 x=2 y=2 grow-radius=1


bloom threshold=-75

[contrast_]

Code:

noise-rgb

gaussian-blur std-dev-y=1.3 std-dev-x=1.3
gray
sepia srgb=1 scale=2
saturation scale=1.2 colorspace=Native

[contrast_]

[Tas_mania]

I tried the edge-desaturate-neon and got this result when changing Mode to 'Difference'.

I like the result but will be trying this on a video stream.

[paynekj]

@contrast_
As you're a "GEGL Wizard" please tell me how to use gegl:contrast-curve without it crashing GIMP

[Tas_mania]

Wizard 101. You don't have to answer non-wizard questions.

[contrast_]

@contrast_
As you're a "GEGL Wizard" please tell me how to use gegl:contrast-curve without it crashing GIMP

LOL, I don't use that filter in GEGL. It crashed for me too even when just typing an =. Something is wrong with it. My expertise is making layer effects in GEGL. I am trying to make a new GEGL filter that allows multiple strokes, a shadow, a bevel, and image file overlay. I will name it GEGL Effects and it will be able to make all sorts of stylish text in a GUI.

I can't figure out how currently. I need to better familiarize myself with GEGL's source code.