Sudoku multispectral filter arrays for spectral snapshot cameras
Year: 2025
Type: article
Abstract: Multispectral filter arrays (MSFAs) are optical components that incorporate pixelated colored filters to selectively filter light at different wavelengths. MSFAs are used in a range of multispectral imaging (MSI) systems, such as mosaic color image sensing and compressive spectral imaging (CSI). The former being cameras with generalized Bayer color filter masks, and the latter where the color filter array is used in concert with a dispersive element to compressively capture spectral images with a 2D focal plane array. Several approaches to optimize the color patterns in MSFAs have been proposed; notably, the placement of the optical elements in most of the proposed approaches is guided by generalizing the constraints defined by Bayer half a century ago. While Bayer dither matrices place spatial constraints in two dimensions, MSFAs generalize these constraints across three dimensions: spatial (2D) and spectral. This paper proposes a new, simple, yet surprisingly effective optimization strategy inspired by the globally recognized combinatorial puzzle Sudoku . The Sudoku-based approach constrains the spatial distribution of colors in the MSFA to form homogeneous patterns rich in high-frequency components across both spatial and spectral dimensions. These properties are desirable for improving image reconstruction. The Sudoku guidelines naturally provide colored patterns that follow blue-noise distributions characterized by the absence of low-frequency components. Notably, if the Sudoku "single digit" constraints along cells, rows, and columns are further generalized to gradually have inter-cell constraints, the resulting colored patterns become increasingly periodic. The proposed framework thus offers mechanisms to generate a broad spectrum of colored patterns, ranging from aperiodic, random blue-noise patterns to periodic Bayer-like patterns. Simulations demonstrate that mosaic and CSI measurements using Sudoku color codes lead to data reconstructions that are comparable to, if not better than, those produced by state-of-the-art MSFA design strategies.
Source: Optics Continuum
Authors: Alvaro Aguirre, Abdullah Alrushud, Gonzalo Arce, Daniel Lau
Institution: University of Kentucky
Language: English
Subfield: Computational Mechanics
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,372
OpenAlex ID: W4413801637