tonemap_aces — 3D render op

• Data kinds: image2d → image2d

• Call: import fullseye as fs; fs.ledger.tonemap_aces(hdr, exposure: 'float' = 1.0) -> 'np.ndarray' (to call the implementation directly, import render_tonemap; render_tonemap.tonemap_aces(hdr, exposure: 'float' = 1.0) -> 'np.ndarray'; from the registry, ops3d.get("tonemap_aces"))

Usage

Compress HDR into [0, 1] LDR with the ACES filmic approximation (Narkowicz 2015). → float64.

Applies f(x) = x(a x + b) / (x(c x + d) + e) to x = hdr * exposure. A film-like S-curve that lifts the shadows and rolls off the highlights gently, giving the "look" that is standard in video production. In the range x < ~7.24 it is strictly monotonically increasing with output < 1 (above that it saturates at 1 and is clipped). Colour (H, W, C) is mapped per channel independently.

Args:

hdr: HDR image. (H, W) or (H, W, C), radiance >= 0.

exposure: exposure scale applied before mapping (positive).

Returns:

float64 LDR image in [0, 1] (same shape as the input).

Raises:

ValueError: empty/non-finite/negative radiance, non-positive exposure (fail-closed).

Background guides (the physics and conventions behind this op)

• blender_interop — Using Blender alongside — build the shape, measure it with fullseye (pitfalls: axes, units, ground truth)

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)

• render_tonemap — py -3.11 examples_3d/render_tonemap.py

Ops the type connects to (they accept image2d as input)

fuse_to_voxel · fit_poly_surface · eval_poly_surface · surface_form_error · background_flatten · polar_unwrap · fit_zernike · matcap_shade

Same category (render)

project_points · render_point_depth · render_volume_projection · render_shaded · ambient_occlusion · cast_shadow · phong_shade · matcap_shade


*Provenance: render_tonemap.py — 3D 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.