tb_project_cylindrical — 2D typed op

Data kinds: pointsimage

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

tb_project_cylindrical: input → output

*The figure is the actual output on a synthetic 128×128 input. Left: input, right: output. Point clouds are drawn as a top-down scatter (brightness = z), 1-D series as a line plot, volumes as the maximum-intensity projection along z, videos as the middle frame, complex images as magnitude; return values that are not pictures are shown as the values themselves.*

Sweeping knob a (0.1 / 0.5 / 0.9, the other knob at its default):

tb_project_cylindrical: knob a sweep (docs site)

Sweeping knob b (0.1 / 0.5 / 0.9, the other knob at its default):

tb_project_cylindrical: knob b sweep (docs site)

Stages (the ops that come before → this op, left to right):

tb_project_cylindrical: stages (docs site)

On other images (synthetic scene / photo / coins. Top row: inputs, bottom row: their outputs. Knobs at default):

tb_project_cylindrical: other inputs (docs site)

Usage

Project onto a cylindrical range image (z_bins, h_res). Azimuth (columns) x z (rows), pixel value = horizontal radius ρ = hypot(x, y).

> The detailed description below is the original text — the summary and the headings are translated.

球面投影が仰角で層を切るのに対し、円柱投影は高さ z を等間隔に切る(壁/柱/回廊の展開に向く)。

画素値は z 軸からの水平距離 ρ(円柱上の点が一定になる自然な不変量)。空セル=0, 近い点優先(最小 ρ)。

z_range=(z_min,z_max) 未指定なら点群の [z.min, z.max] を採用。z 幅ゼロは fail-closed(ValueError)。

行 0 = 上端(z=z_max)。z_range 外、z 軸上(ρ=0)、非有限座標の点は落とす。

2-D 進化レジストリへ橋渡しした 3d の op `project_cylindrical。実装は同じで、呼び出し規約だけ op(v, a, b) に合わせてある。ah_res(既定 1024)、bz_bins`(既定 64)を振る。

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.

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.

img_to_points 0.50 0.50
tb_project_cylindrical 0.50 0.50

▸ Load this pipeline  ·  Load & run

Runnable examples (verified samples that actually call this op)

The examples below call the underlying ledger op project_cylindrical. This bridge op is the same implementation adapted to the fn(v, a, b) convention, so the behaviour carries over unchanged (only the call form differs).

curvilinear_projpy -3.11 examples_3d/curvilinear_proj.py

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

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

Same category (typed)

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


*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.