vol_label_volume_render — VOLCOLOR `render` op

• Data kinds: labels → rgbimage

• Call: import fullseye as fs; fs.ledger.vol_label_volume_render(labels, axis='z', mode: 'str' = 'front', seed: 'int' = 0, alpha: 'float' = 0.35, background=(0.0, 0.0, 0.0)) (to call the implementation directly, import volcolor; volcolor.vol_label_volume_render(labels, axis='z', mode: 'str' = 'front', seed: 'int' = 0, alpha: 'float' = 0.35, background=(0.0, 0.0, 0.0)); from the registry, opsvolcolor.get("vol_label_volume_render"))

Usage

A composited projection of the coloured labels, (H, W, 3), built with numpy alone.

*mode*:

• "front" -- the colour of the first non-background voxel hit along the viewing direction (opaque display).

• "back" -- the last one hit (the shape seen from the back side).

• "alpha" -- front-to-back over compositing (Porter & Duff 1984). Non-background voxels are stacked from the front, each with opacity *alpha*. Depth overlaps show, while the front colour always comes out stronger than what is behind it.

mode="max" is rejected (ValueError). Taking the max of RGB per channel produces a colour that belongs to no part, with the red component from part A and the green component from part B. Measured (3 plates overlapping with an offset in z, (16, 16, 16), seed=0, axis="z"): the per-channel max projection (16, 16) created, out of 168 foreground pixels, colours matching no palette row in 90 pixels. For the same input "front" gives palette colours in all 256 pixels (tests/test_volcolor.py::test_channelwise_max_would_invent_colours).

*axis* is "z"/0 (returns (H, W, 3)), "y"/1 ((D, W, 3)), "x"/2 ((D, H, 3)).

Raises ValueError for an unknown *mode* / *axis*, an *alpha* outside [0, 1], or a bad label volume.

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)

• voxel_labels_color — py -3.11 examples/voxel_labels_color.py

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

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Same category (`render`)

vol_labels_to_meshes

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

vol_label_volume_render — VOLCOLOR render op