tonemap_reinhard — 3D `render` op

• Data kinds: image2d → image2d

• Call: import fullseye as fs; fs.ledger.tonemap_reinhard(hdr, exposure: 'float' = 1.0, white: 'float | None' = None) -> 'np.ndarray' (to call the implementation directly, import render_tonemap; render_tonemap.tonemap_reinhard(hdr, exposure: 'float' = 1.0, white: 'float | None' = None) -> 'np.ndarray'; from the registry, ops3d.get("tonemap_reinhard"))

Usage

Compress HDR into [0, 1] LDR with Reinhard tone mapping. → float64, the same shape as the input.

For the exposure-scaled x = hdr * exposure:

• white is None … the basic form x / (1 + x). Maps [0, ∞) strictly monotonically increasing onto [0, 1) and never clips (strictly preserves tonal order over the whole range).

• white given … the extended form x (1 + x/white²) / (1 + x). Maps white exactly to 1.0 and devotes much of the range to values below white (inputs above white exceed 1, so they are clipped to [0, 1]).

Colour (H, W, C) is mapped per channel independently. Unlike naive clipping min(x, 1), it keeps a monotonic tonal scale even in the highlight region of values > 1.

Args:

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

exposure: exposure scale applied before mapping (positive).

white: optional white-point (positive). None gives basic Reinhard (recommended; monotonic everywhere).

Returns:

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

Raises:

ValueError: empty/non-finite/negative radiance, non-positive exposure/white (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_beauty — py -3.11 examples_3d/render_beauty.py

• 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).*

tonemap_reinhard — 3D render op