fourier_smooth — SHAPE2D `descriptor` op

• Data kinds: pairs → pairs

• Call: import fourierdesc; fourierdesc.fourier_smooth(points, keep) (or opsshape2d.get("fourier_smooth"))

Usage

> This operator's description has not been translated yet. The original text follows as it is.

輪郭を複素 FFT で帯域制限して平滑化する。

輪郭を複素信号 z(t)=x(t)+i·y(t) と見て FFT し、低周波 `keep` 本(と対称成分)

だけ残して逆変換する。keep が小さいほど滑らか(高周波=細部/ノイズを落とす)。

keep が全周波数以上なら恒等。返り値は入力と同点数の (N,2)。

Detailed usage guide

• shape_description_2d 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.

Runnable examples (verified samples that actually call this op)

• contour_fourier — py -3.11 examples/contour_fourier.py

Ops the type connects to (they accept `pairs` as input)

elliptic_fourier · add_frame_corners · warp_tps_image · warp_piecewise_affine · morph · morph_sequence

Same category (`descriptor`)

elliptic_fourier · reconstruct · invariants · normalize · descriptor_distance · from_xld

*Provenance: fourierdesc.py — SHAPE2D operator registry. This per-op note is generated by tools/opdocs.py md (do not hand-edit).*

fourier_smooth — SHAPE2D descriptor op