GIMP plug-in replacements
Several of Gwyddion data synthesis modules reimplement – usually better – ideas from old GIMP ‘Render’ plug-ins written or improved by Yeti about than 15 years ago: FourierCompose, ParticleDeposition, PerlinNoise, Plasma2, TuringPattern, Voronoi, WavesOfChaos or WaterSurface.
The GIMP plug-ins have not been updated since, mostly because Gwyddion's direct data arrays are a better match for generation of 2D maps that involve FFT or solving differential equations than GIMP's tile-based system. In addition, false colour mapping comes free in Gwyddion and is non-destructive. On the other hand, some useful operations that are quite natural in GIMP, in particular mapping RGB channels to three different functions, may be cumbersome in Gwyddion because it does not work with colour images – it works with height maps. So one has to generate the three channels in sequence and compose them as RGB afterwards.
Anyway, there is essentially zero chance of further development of the GIMP plug-ins. But people still ask about them occasionally. Here is an overview of full or partial replacements of the GIMP render plug-ins by Gwyddion data synthesis modules. All images on this page were generated in Gwyddion.
FourierCompose
Gwyddion's Spectral synthesis module is more or less a direct equivalent of the GIMP FourierCompose plug-in. Both generate images with given density of spatial frequencies (and random phases) with using inverse Fourier transform.
There is a second module that employs Fourier synthesis, Phases. However, it mostly uses FFT as a dirty trick to approximate images that could take weeks to obtain if simulated properly. So they output is quite different from FourierCompose.
ParticleDeposition
Columnar synthesis in Gwyddion is essentially exactly the same model of columnar film growth as the GIMP ParticleDeposition plug-in. Even some of the parameters are (roughly) equivalent, although the naming has changed.
But there is more. Gwyddion has several additional modules that simulate some deposition process (in fact, there seems to be no end of them): Ballistic and Diffusion represent classical physical models, ballistic deposition and diffusion-limited aggregation. Arguably, Object, Fibre and Particle data synthesis modules are also particle deposition models.
PerlinNoise
There is no Gwyddion module that reimplements the same algorithm as GIMP PerlinNoise plug-in. That being said, Spectral synthesis with Gaussian multiplier enabled generates surfaces that are sufficiently similar that no specific replacement is necessary.
Plasma2
There are essentially two replacements for the probably most popular GIMP plug-in from the set, Plasma2. Again, Gwyddion's Spectral can generate a variety of images from the same class – in particular the fractal-like images can be even completely mathematically equivalent.
The second Gwyddion module is much closer to the original algorithm used in Plasma2, becaust it also works by spatial subdivision. Although Brownian has a somewhat different set of options, if you want Plasma2-like images generated with some heavy-tailed distributions, it certainly can do that.
TuringPattern
GIMP TuringPattern plug-in has several counterpart modules in Gwyddion, close or removed to various degree.
Coupled PDEs is closest to the GIMP plugin. It uses the same set of coupled non-linear partial differential equations to produce the Turing pattern. This is, however, the only pattern it can currently produce.
Domains simulates the characteristic spirals and other shapes produced by non-equilibrium Ising models. The images it can calculate are neither a subset nor a superset of TuringPattern's, but there is a considerable intersection.
The already mentioned Phases module essentially generates one specific type of pattern that TuringPattern did. The physical system motivating its creation was different, but the resulting patterns are similar.
And there is also the Anneal module which represents a different kind of cellular automaton than Domains. But again, it simulates a phase separation process.
Voronoi
If you like the GIMP Voronoi plug-in you must love the Lattice module in Gwyddion. It implements the same surface construction, but it has much more flexibility and interesting options. It does not do one thing the GIMP plug-in does, generation of tileable images (the plug-in was cheating in a sense).
WavesOfChaos
The WavesOfChaos GIMP plug-in currently does not have any replacement or successor in Gwyddion. Stay tuned.
WaterSurface
GIMP WaterSurface plug-in was originally created by Kyoichiro Suda and Yeti only did some improvements and rewrites. Anyway, it was also reimplemented in Gwyddion as Waves. It is not a drop-in replacement but you can recognise a number of identical parameters between the GIMP plug-in and the Gwyddion module.
Other generators
Some Gwyddion generators also create structures and patterns that do not correspond to any of the GIMP plug-ins. For instance Patterns creates various (semi)regular patterns and Pile-up generates surfaces from piled up geometrical shapes. There are also simple point and line noise modules Noise and Line Noise.
Transferring images
Now the most important point, especially if you are not faimilar with Gwyddion. How to get an image from Gwyddion to GIMP:
- Use Ctrl-C/Ctrl-V (Ctrl-Shift-V) to copy a false-colour mapped (or grey scale) height field from Gwyddion to GIMP.
- Use ‘Save As’ in Gwyddion to export to a pixmap image format (PNG, TIFF, WebP, ...), disabling all rulers and physical scales.
You can do post-processing in GIMP, but Gwyddion also offers a bunch of interesting (and sometimes complementary) functions. You may want to save the data as a GWY file to preserve it as double-precision data that can be processed or colour-mapped differently later.
