post op• Data kinds: rgb → rgb
• Call: import fullseye as fs; fs.ledger.bloom(rgb, threshold=0.8, sigma=4.0, intensity=0.6) (to call the implementation directly, import gfx2d; gfx2d.bloom(rgb, threshold=0.8, sigma=4.0, intensity=0.6); from the registry, opsgfx2d.get("bloom"))
Bleed the bright parts of an image into their neighbourhood.
The classical three steps: isolate what is above threshold, blur it by a Gaussian of sigma, add intensity times the result back, clip.
A *linear-light* operator: light spreading in a lens adds radiance. Running it on sRGB-encoded values makes the halo too strong in the mid-tones — srgb_to_linear first, linear_to_srgb after.
Exact identities: intensity=0 and threshold >= 1 both return the input bit for bit, and a black image stays black.
The added energy is *not* conserved by the clip at the end. The suite measures both halves: on a centred bright blob the Gaussian preserves the bright mass to 5.0e-16 relative, so everything lost after that is the clip — on a random scene with a saturated square, 2.69 % of the pixels clip and 1.65 % of the total energy is thrown away, and neither number is returned to the caller.
• 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.
• gfx2d_scene — py -3.11 examples/gfx2d_scene.py
• poc_public_camera_heading_real — py -3.11 examples/poc_public_camera_heading_real.py
rgb as input)srgb_to_linear · linear_to_srgb · blend_mode · light_mask · normal_map_decode · vignette · chromatic_aberration · film_grain
post)vignette · chromatic_aberration · film_grain · color_lut · color_grade · dither · palette_quantize
*Provenance: gfx2d.py — GFX2D 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.