distortion_map — OPTICS imaging_sim op

Data kinds: tabletable

Call: import lensimage; lensimage.distortion_map(system, image_size=(256, 256), pixel_pitch_um=5.5, fields=None, order=2) (or opsoptics.get("distortion_map"))

Usage

Real chief-ray height versus the paraxial one, and the remap grid (`table`).

Fields (degrees for an object at infinity, object heights in mm otherwise)

default to 9 values from the axis to the sensor corner

(`hypot(H, W)/2 · pitch`). For each, the real chief ray is traced to the

image plane (`r_real) and compared with the ideal height f·tanθ`

(or `m·H); distortion_pct = (r_real − r_ideal)/r_ideal · 100` —

negative is barrel. A radial polynomial `r_real = r(1 + k1 r² + k2 r⁴ …)`

(*order* even terms) is fitted and inverted on a dense table to build

`grid_rows / grid_cols` — for every real sensor pixel, the

fractional ideal-image pixel it sees (the inverse remap a renderer feeds to

`scipy.ndimage.map_coordinates). max_distortion_pct` is at the

corner. A paraboloid mirror with the stop on it and any system on axis give

zero (< 1e-7 %); the plano-convex singlet (stop on its first surface) is

barrel: −0.0059 % at the corner of a 2048 × 5.5 µm sensor (4.55°) and

−0.065 % at 15°, the doublet −0.28 % at 15° (measured, pinned in the tests).

Family-wide input contract (fail-closed)

Every optics op validates its input before computing (nothing slips through silently):

Units are baked into the argument name_mm / _um / _deg / _mrad. Confusing mm with µm does not crash; it yields a plausible-looking wrong answer, so the name prevents it. Nothing here guesses the unit from the magnitude.

• **Strings raise ValueError** — float('50') succeeds, so an unparsed configuration value would slip through as a length (measured: thin_lens('50', '200') returned a plausible 66.667 mm). bool is refused too, as the implicit promotion True == 1.

• **complex / masked arrays raise ValueError (real-valued slots only; silently dropping the imaginary part or peeling off the mask is refused). NaN/Inf raises ValueError on every input.**

Division by zero and its relatives are refused by name: focal length 0, radius of curvature 0, refractive index <= 0, a fully opaque aperture (all zeros, so the normalisation is 0/0), a PSF whose sum is <= 0, a Stokes vector with S0 = 0, and an object sitting at the front focal point (the image is at infinity).

Only two ops return a non-finite value, and both state it as a contract: depth_of_field returns far_mm = inf beyond the hyperfocal distance (that is what the hyperfocal distance means), and gaussian_beam returns wavefront_radius_mm = inf at the waist (the radius of curvature of a plane wavefront). Both also return a finite companion (far_is_infinite / curvature_per_mm). **Any other silent NaN/Inf is detected internally and raises ValueError** — "float64 overflowed" and "the answer is infinite" are different claims, so the first is never returned wearing the face of the second.

Size caps: generated grids are capped by optics.MAX_GRID (4096); supplied fields/PSFs/apertures by optics.MAX_FIELD_ELEMENTS (2^24); ABCD element chains by optics.MAX_SYSTEM_ELEMENTS (1024); Zernike by MAX_ZERNIKE_TERMS (512) / MAX_ZERNIKE_ORDER (40) / MAX_ZERNIKE_BASIS (2^25). This closes, fail-closed, the paths where a small argument triggers a huge internal allocation (measured: n_max=40 × 4096² needs 108 GB).

Physically impossible states are refused too: a Stokes vector with degree of polarisation > 1, negative transmittance, negative intensity, and invalid Zernike indices such as n-|m| odd.

Detailed usage guide

optics_imaging family guide

Background guides (the physics and conventions behind this op)

mv_cables — ケーブル(規格・速度・給電・ロボットケーブル)

mv_cameras — 産業用カメラメーカー(センサとの紐付け・ラインスキャン / TDI)

mv_frame_grabbers — フレームグラバーボード(光学系ではないが、撮れるかを決める)

mv_image_sensors — 産業用イメージセンサ(現行品中心)

mv_standards — カメラインターフェースの規格と団体

virtual_machine_vision — 仮想マシンビジョン — パラメータの洗い出しとオブジェクト模型

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)

lens_defect_dataset_demopy -3.11 examples/lens_defect_dataset_demo.py

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

abcd_matrix · wavefront_stats · paraxial_trace · seidel_coefficients · spot_stats · tolerance_analysis · wavefront_from_opd · spot_diagram

Same category (imaging_sim)

psf_from_opd · render_through_lens · defect_dataset · calibration_views


*Provenance: lensimage.py — OPTICS 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.