tb_lowpass — 2D typed op

Data kinds: signalsignal

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

Usage

Butterworth low-pass (scipy, zero-phase filtfilt). *cutoff* must be inside `(0, rate/2)`; an out-of-Nyquist cutoff raises instead of passing the signal through. A signal too short for zero-phase filtfilt also raises (the message names the exact minimum) instead of silently coming back unfiltered.

Typed bridge of the 1d op `lowpass into the 2-D evolution registry: the same implementation, called under the op(v, a, b) convention. a drives order (default 4); b` is unused.

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.

Runnable examples (verified samples that actually call this op)

• (none yet)

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

identity · tb_create_funct_1d_array · tb_smooth_funct_1d_gauss · tb_smooth_funct_1d_mean · tb_derivate_funct_1d · tb_integrate_funct_1d · tb_zero_crossings_funct_1d · tb_abs_funct_1d

Same category (typed)

tb_points_to_voxel · tb_estimate_point_normals · tb_iss_keypoints · tb_angle_3points · tb_project_points · tb_render_point_depth · tb_statistical_outlier_removal · tb_radius_outlier_removal


*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.