render_through_lens — OPTICS imaging_sim op

Data kinds: image2d × tableimage2d

Call: import lensimage; lensimage.render_through_lens(image, system, pixel_pitch_um=5.5, field_of_view=None, zones=3, noise=None, seed=0, illumination='traced', size=None, oversample=None) (or opsoptics.get("render_through_lens"))

Usage

Render an ideal irradiance image as the sensor behind *system* would record it (`image2d`).

*image* (H×W, non-negative) is the ideal (paraxial) image on a sensor of

*pixel_pitch_um* pixels centred on the optical axis; with *field_of_view*

(half field to the sensor corner: degrees for an object at infinity,

object height in mm otherwise) the picture is first zoomed so the corner

sees that field. Pipeline: (a) inverse distortion remap

(:func:distortion_map grid, `scipy.ndimage.map_coordinates` order 1);

(b) spatially varying blur — a `zones×zones` lattice of tile centres,

each with its own pixel-integrated :func:psf_from_opd (the +y-field PSF

rotated to the tile azimuth), blended with bilinear (tent) weights so

seams vanish; (c) relative illumination: `"traced"` = fraction of the

field's ray bundle that reaches the image (vignetting, from

:func:raytrace.ray_bundle) normalised to the axis, times cos⁴ (obliquity,

objects at infinity only), `"cos4" = the classic law alone, "none"`;

(d) sensor, when *noise* is `True or a dict `{"full_well": 20000,

"read_e": 3.0, "bits": 12, "exposure": 1.0, "dark_e": 0.0}``: electrons =

irradiance × exposure × full_well, Poisson shot noise

(:func:photoncount.photon_sample), Gaussian read noise, quantisation to

*bits*, returned as DN/(2^bits − 1). With `noise=None` the float

irradiance is returned untouched (deterministic; the noisy path is

deterministic for a given *seed* too).

*oversample* defaults to whatever keeps at least 2 PSF samples per pixel

(`max(4, ceil(2·λ·F#/pitch))`). Ground truth: a δ image through the

f/2 paraboloid gives the pixel-integrated Airy PSF; a checkerboard through

it comes back undistorted (correlation > 0.99); energy is conserved to 1 %

with illumination off; noise off is bit-reproducible.

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 image2d as input)

fraunhofer_pattern · psf_to_mtf · illumination_uniformity · surface_defect · defocus_blur

Same category (imaging_sim)

psf_from_opd · distortion_map · 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.