The IR dust reconstruction in negpy/features/retouch/logic.py ports algorithm concepts (continuous defect score, score-weighted multiscale reconstruction, original-floor writer rule, interior-radius routing with feathered compositing) from digital-fauxice, Copyright (c) 2026 Rohan Pandula, MIT License. https://github.com/rohanpandula/digital-fauxice
The Plustek USB driver lives in the separate pyopticfilm package. NegPy integrates it via negpy/infrastructure/scanners/plustek_backend.py. That driver includes
material derived from or informed by the SANE Project genesys backend
(Scanner Access Now Easy), GNU GPL:
https://gitlab.com/sane-project/backends
Relevant upstream areas include (non-exhaustive): backend/genesys USB protocol, register tables, motor/sensor/frontend tables, and image pipeline helpers. Plustek, OpticFilm, and related names are trademarks of their respective owners; NegPy is not affiliated with or endorsed by Plustek Inc.
The spectral dye density curves in scripts/print_dyes/kodak_ra4_e4021.csv (Kodak E-4021, 2009) and scripts/print_dyes/kodak_2393_h1_2393.csv (Kodak H-1-2393t, 1998), and the 2393 characteristic curves that the Kodak Vision Premier 2393 profile in negpy/features/exposure/papers.py is fitted to, are derived from spektrafilm by Andrea Volpato, licensed CC BY-SA 4.0:
https://github.com/andreavolpato/spektrafilm https://github.com/andreavolpato/spektrafilm/blob/main/SPEKTRAFILM_LICENSE.txt
Modified by NegPy: the CSVs keep each profile's channel_density on its 5 nm grid where all three dyes are defined; print_luts/kodak_e4021.npz and kodak_2393.npz are baked from them, and papers.py holds the tone constants fitted to that data. NegPy distributes them under the GPL v3, which Creative Commons lists as a BY-SA compatible license.
The print LUTs negpy/features/exposure/print_luts/fuji_ca_dpii.npz and fuji_ca_hd.npz, and the paper white, base tint and Dmax of the Fujicolor Crystal Archive stocks in papers.py, are derived from Fujifilm's Frontier-PD printer profiles for Crystal Archive DPII and HD paper (FUJIFILM, made with Argyll CMS). The profiles are not distributed with NegPy.
The print LUT negpy/features/exposure/print_luts/frontier.npz is derived from the color reproduction tables (ColorData.dat) of the Fujifilm Frontier 350/370 A1 system software v7.6. The tables are not distributed with NegPy.
scripts/crosstalk_dyes/kodak_vision3_dyes.csv is the mean of spektrafilm's traces of the Kodak VISION3 50D, 200T, 250D and 500T dye curves (H-1-5203, H-1-5207, H-1-5213, H-1-5219), resampled to 5 nm, under the same license. The Kodak consumer and VERITA 200D crosstalk estimates in crosstalk/ are fitted with it.
The DX numbers, the Kodak Ultra Max edge code and two respool sources in the
edge entries of gear/film_stocks.json come from The Big Film Database
(dxdatabase) © 2018 by Dxdatabase, licensed CC BY-SA 4.0 and provided as is,
without warranties:
http://industrieplus.alwaysdata.net/dxdatabase/ https://github.com/dxdatabase/Open-source-film-database https://thebigfilmdatabase.merinorus.com/ https://creativecommons.org/licenses/by-sa/4.0/
Modified by NegPy: each four-digit DX number is split into the part 1 and part 2 of the film edge barcode. NegPy distributes them under the GPL v3, which Creative Commons lists as a BY-SA compatible license.
The negpy_core extension module links these Rust crates: PyO3 and rust-numpy (MIT OR Apache-2.0; rust-numpy BSD-2-Clause), rayon and crossbeam (MIT OR Apache-2.0), ndarray, num-traits, num-complex, num-integer, matrixmultiply and rawpointer (MIT OR Apache-2.0), libc, once_cell, either, portable-atomic and rustc-hash (MIT OR Apache-2.0), multiversion and target-features (MIT OR Apache-2.0), libm (MIT, a port of musl's math library), rustfft, realfft, primal-check, strength_reduce and transpose (MIT OR Apache-2.0), miniz_oxide (MIT OR Zlib OR Apache-2.0), adler2 (0BSD OR MIT OR Apache-2.0), crc32fast and cfg-if (MIT OR Apache-2.0). negpy_core/Cargo.lock lists the exact versions.
negpy_core/src/resize.rs and negpy_core/src/filter.rs port OpenCV's float32 area
resize, separable filter engine and bit-exact Gaussian kernel (including its
softfloat exp table) so their results match cv2 bit for bit. negpy_core/src/lsd.rs
ports OpenCV's line segment detector (modules/imgproc/src/lsd.cpp),
negpy_core/src/inpaint.rs its Navier-Stokes inpaint, and
negpy_core/src/seam.rs its dynamic-programming seam finder. OpenCV, Apache
License 2.0. https://github.com/opencv/opencv
negpy_core/src/sift.rs and negpy_core/src/register.rs port OpenCV 4.13's SIFT detector and descriptor (sift.dispatch.cpp, sift.simd.hpp), its RANSAC similarity estimate and Levenberg-Marquardt refinement (ptsetreg.cpp, levmarq.cpp). OpenCV, Apache License 2.0. SIFT is by David G. Lowe; its patent expired in March 2020.