alife_reaction_bz — 2D artificial-life op

Data kinds: imageimage

Call: fullseye.apply(img, "alife_reaction_bz", a=0.5, b=0.5) (the 2-D model is one image plus two scalar knobs a,b∈[0,1])

alife_reaction_bz: 入力 → 出力

*The figure is the real output on a synthetic 128×128 input. Left: input, right: output (a non-image return value is shown as the value itself).*

Usage

Belousov-Zhabotinsky-like excitable medium (Greenberg-Hastings automaton).

A 3-state excitable lattice -- 0 = rest, 1 = excited, 2 = refractory -- with

the Greenberg-Hastings rule: an excited cell becomes refractory, a refractory

cell relaxes to rest, and a resting cell fires when at least `thr` of its 8

Moore neighbours are excited. Because a refractory cell cannot be re-excited,

excitation cannot back-propagate and the fronts organise into the travelling

waves and rotating spirals of the BZ reaction. The image tertiles set the

initial state (>2/3 excited, 1/3..2/3 refractory, else rest). `a` sets the

excitation threshold thr = 1 + int(3a) neighbours, `b` the step count

1 + int(20b). Returns state/2.

Detailed usage guide

gallery2d_physics_alife_3d family guide

References (sample data, literature)

• Sample-data catalog (download URLs / licences) — 2-D uses skimage.data (BSD/public domain) plus synthetic images; 3-D lists download URLs for real data sources (Stanford, PDS, …).

• Operator provenance and references — the sources of the research/methods this op family came from.

• The canonical algorithm (author, year) and its uses are named in the family usage guide above.

Try it in Studio

The program below has been verified to run (same input as the figure). In Studio's help this block becomes buttons that load and run it on the spot.

alife_reaction_bz 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

gallery2d_physics_alife_3dpy -3.11 examples/gallery2d_physics_alife_3d.py

sim2real_and_alifepy -3.11 examples/sim2real_and_alife.py

Ops the type connects to (they accept image as input)

identity · gaussian · mean_box · bilateral · unsharp · median · min_filter · max_filter

Same category (artificial-life)

alife_gray_scott · alife_turing · alife_life_step · alife_cyclic_ca · alife_perona_malik · alife_curvature_flow · alife_dla · alife_wolfram1d


*Provenance: ops.py — 2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

© 2026 Kazufumi Furuse — Fullseye operator documentation. Licensed under Apache-2.0.