ct_adjoint_project — TOMOGRAPHY ct_scan op

• Data kinds: projstack × ctgeometry → voxel

• Call: import fullseye as fs; fs.ledger.ct_adjoint_project(projections, geometry, device='auto') (to call the implementation directly, import ctscan; ctscan.ct_adjoint_project(projections, geometry, device='auto'); from the registry, opstomography.get("ct_adjoint_project"))

• GPU: none (CPU reference implementation only)

Usage

The exact transpose A^T of ct_forward_project.

<A x, y> = <x, A^T y> holds to rounding, on every scan. This is what an iterative solver needs; it is not the reconstruction fdk_reconstruct does.

:param projections: (view, V, U) array. :param geometry: dict from ct_scan_geometry. :param device: "auto", "cpu" or "cuda". :returns: (Z, Y, X) float volume. :raises ValueError: on a shape that disagrees with the geometry. Empty input

(projections with 0 elements) raises ValueError.

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)

• ct_scan_modes — py -3.11 examples/ct_scan_modes.py

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

radon_volume · ct_forward_project

Same category (ct_scan)

ct_scan_geometry · shepp_logan_3d · ellipsoid_phantom · ellipsoid_projections · ct_forward_project · fdk_reconstruct · sirt_reconstruct · os_sart_reconstruct

*Provenance: ctscan.py — TOMOGRAPHY 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.