Authors:
Marina Ljubenović
1
;
Mário A. T. Figueiredo
2
and
Arianna Traviglia
1
Affiliations:
1
Center for Cultural Heritage Technology, Istituto Italiano di Tecnologia, Venice, Italy
;
2
Instituto de Telecomunicações, Instituto Superior Técnico, Lisbon, Portugal
Keyword(s):
THz TDS, Deblurring, Denoising, Low-Rank.
Abstract:
Terahertz (THz) time-domain imaging holds immense potential for material characterization, capturing three-dimensional data across spatial and temporal dimensions. Despite its capabilities, the technology faces hurdles such as frequency-dependent beam-shape effects and noise. This paper proposes a novel, dual-stage framework for improving THz image resolution beyond the wavelength limit. Our method combats blur at lower frequencies and noise at higher frequencies. The first stage entails selective deblurring of lower-frequency bands, addressing beam-related blurring, while the second stage involves denoising the entire THz hyperspec-tral cube through dimensionality reduction, exploiting its low-rank structure. The synergy of these advanced techniques—beam shaping, noise removal, and low-rank representation—forms a comprehensive approach to enhance THz time-domain images. We present promising preliminary results, showcasing significant improvements across all frequency bands, which is
crucial as samples may display varying features across the THz spectrum. Our ongoing work is extending this methodology to complex scenarios such as analyzing multilayered structures in closed ancient manuscripts. This approach paves the way for broader application and refinement of THz imaging in diverse research fields.
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