polarization_demosaic_color — OPTICS polarization op

Data kinds: image2drgbvolume

Call: import fullseye as fs; fs.ledger.polarization_demosaic_color(raw, layout=((90.0, 45.0), (135.0, 0.0)), bayer='RGGB') (to call the implementation directly, import optics; optics.polarization_demosaic_color(raw, layout=((90.0, 45.0), (135.0, 0.0)), bayer='RGGB'); from the registry, opsoptics.get("polarization_demosaic_color"))

Usage

Split a colour polarisation-sensor mosaic (Sony IMX250MYR family, a 4x4 block = a 2x2 Bayer block whose every colour site is itself a 2x2 block of polarisers) into four RGB images: `(4, H, W, 3) in :data:POLARIZATION_SWEEP_ANGLES order, each channel interpolated to full resolution. The rgbvolume` sort carries it (four "slices" of RGB).

Two closed forms composed, no new estimate: (1) the pixels at each of the

four polariser positions form a plain Bayer mosaic at half resolution, so

each is demosaicked with :func:gfx2d.raw_demosaic_bilinear and written

back to its positions — after which every pixel has RGB and the

polarisation mosaic is still interleaved; (2) each RGB channel is then a

monochrome polarisation mosaic, handled by :func:polarization_demosaic.

This is the decomposition Polanalyser documents for that sensor; *bayer*

is the pattern of the half-resolution Bayer grid (`RGGB` for the

IMX250MYR as read row-major from the top-left site) and *layout* the

polariser angles inside a site.

Ground truth: twelve affine planes (4 angles x RGB) mosaicked and split come

back to 1e-12 away from the border (bilinear is exact on affine fields, and

the composition of two exact steps is exact).

Raises `ValueError`: *raw* is not 2-D, has a height or width that is

not a multiple of 4, is non-finite, or *layout* / *bayer* is invalid.

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

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)

polarization_camera_pipelinepy -3.11 examples/polarization_camera_pipeline.py

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

Same category (polarization)

jones_element · jones_apply · stokes_from_jones · mueller_element · mueller_apply · stokes_analyze · polarization_demosaic · mueller_from_intensities


*Provenance: optics.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.