tono/GWYDDION_FEATURE_GAP.md

Gwyddion Features Not Yet in argonode

Reference for future implementation. Grouped by value to typical SPM workflows.

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High Value

#	Feature	Gwyddion Source	Description
1	Line Correction	linecorrect.c, linematch.c	Row-by-row median/polynomial alignment. Essential for raw SPM data with scan-line artifacts.
2	Scar Removal	scars.c	Detect and interpolate scan-line defects (horizontal streaks).
3	Facet Leveling	facet-level.c	Orient the dominant surface facet to horizontal. Better than plane level for terraced/stepped surfaces.
4	Morphological Mask Ops	mask_morph.c	Erode, dilate, open, close on grain masks. Needed to clean up thresholded masks. DONE
5	1D FFT Filter	fft_filter_1d.c	Bandpass/lowpass/highpass filtering of LINE profiles. DONE
6	2D FFT Filter	fft_filter_2d.c	Frequency-domain filtering of DATA_FIELDs (remove periodic noise, etc.). DONE
7	Autocorrelation (ACF)	acf2d.c	2D autocorrelation function. Reveals periodic structures and correlation lengths.
8	PSDF	psdf2d.c	Radial/2D power spectral density function. Complementary to ACF for roughness characterization.
9	Fractal Dimension	fractal.c	Multiple methods: partitioning, cube counting, triangulation, PSDF, HHCF. Quantifies surface complexity.
10	Curvature	curvature.c	Local mean/Gaussian curvature maps. Useful for feature identification.
11	Grain Distance Transform	mask_edt.c	Euclidean distance from grain boundaries. Useful for spatial distribution analysis.
12	Watershed Segmentation	grain_wshed.c	Automatic grain detection without manual threshold. More robust than simple thresholding.
13	Rotate / Flip	rotate.c, basicops.c	Basic geometric transforms (90°, arbitrary angle, mirror).
14	Crop	crop.c	Extract sub-region of a field. DONE

Medium Value

#	Feature	Gwyddion Source	Description
15	Correlation / Pattern Matching	crosscor.c, maskcor.c	Find repeated features or align images via cross-correlation.
16	Slope Distribution	slope_dist.c	Angular histogram of surface slopes. Characterizes surface texture directionality.
17	Grain Filtering	grain_filter.c	Remove particles by size, height, or border contact. Refine grain masks post-detection.
18	Field Arithmetic	arithmetic.c	Add/subtract/multiply/divide two DATA_FIELDs. Useful for difference maps, normalization.
19	Spot Removal	spotremove.c	Interpolate over selected point defects (dust, spikes).
20	Tip Modeling / Deconvolution	tip_blind.c, tip_model.c	Estimate tip shape from image, deconvolve to recover true surface.
21	Radial Profile	rprofile tool	Azimuthally averaged profile from a center point. Good for circular features.
22	Wavelet Transform	dwt.c, cwt.c	Discrete/continuous wavelet analysis. Multi-scale roughness decomposition.
23	Scale / Resample	scale.c, resample.c	Resize fields with interpolation.
24	Gradient	gradient.c	Compute x/y gradient magnitude maps.
25	Custom Convolution	convolution_filter.c	User-defined kernel convolution.
26	Local Contrast Enhancement	local_contrast.c	Enhance visibility of local features in images.

Lower Priority

#	Feature	Gwyddion Source	Description
27	Drift Correction	drift.c	Compensate for thermal/piezo drift between scan lines.
28	Affine / Perspective Correction	correct_affine.c, correct_perspective.c	Fix geometric distortions from scanner nonlinearity.
29	MFM Analysis	mfm_*.c	Magnetic force microscopy: field calculation, shift finding.
30	Lattice Measurement	measure_lattice.c	Detect and measure periodic lattice structures from ACF/FFT.
31	Hough Transform	hough.c	Detect lines and circles in images.
32	Image Stitching / Merging	merge.c, stitch.c	Combine multiple overlapping scans into one image.
33	Facet Analysis	facet_analysis.c	Orientation distribution of surface facets (stereographic projection).
34	Shape Fitting	fit-shape.c	Fit geometric primitives: sphere, paraboloid, cylinder, etc.
35	Synthetic Surface Generation	*_synth.c (~20 modules)	Generate test surfaces: FBM, noise, lattice, waves, particles, fibers, etc.
36	Entropy	entropy.c	Information entropy of height distribution.
37	Indentation Analysis	indent_analyze.c, hertz.c	Nanoindentation curve fitting (Hertz model).
38	Deconvolution	deconvolve.c	Blind/regularized deconvolution for image restoration.
39	Canny / Harris Detection	filters.c	Corner and edge feature detection beyond basic Sobel/Prewitt.
40	Kuwahara Filter	filters.c	Edge-preserving smoothing filter.

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Already Implemented in argonode

For reference, these Gwyddion equivalents are already covered:

argonode Node	Category	Gwyddion Equivalent
Load Image / Load SPM File	io	File import (gwy, sxm, ibw)
Save Image	io	File export
Coordinate	io	—
Plane Level	level	level.c
Polynomial Level	level	polylevel.c
Fix Zero	level	level.c (fix_zero)
Gaussian Filter	filters	filters.c (gaussian)
Median Filter	filters	filters.c (median)
Edge Detect	filters	edge.c (sobel, prewitt, laplacian, LoG)
1D FFT Filter	filters	fft_filter_1d.c (lowpass, highpass, bandpass, notch)
2D FFT Filter	filters	fft_filter_2d.c (lowpass, highpass, bandpass, notch)
Statistics	analysis	stats.c
Height Histogram	analysis	linestats.c (dh)
2D FFT	analysis	fft.c
Cross Section	analysis	profile tool
Profile Roughness	analysis	roughness.c (Ra, Rq, Rsk, Rku, Rp, Rv, Rt)
Line Math	analysis	linestats.c
Threshold Mask	mask	threshold.c, otsu_threshold.c
Mask Morphology	mask	mask_morph.c (erode, dilate, open, close)
Mask Invert	mask	—
Mask Combine	mask	— (boolean AND, OR, XOR, subtract)
Particle Analysis	particles	grain_stat.c
Preview / 3D View / Print Table	display	Presentation, 3D view