Dual-camera design for hyperspectral and panchromatic imaging, using a wedge shaped liquid crystal as a spectral multiplexer

Shmilovich, Shauli; Oiknine, Yaniv; Abuleil, Marwan J.; Abdulhalim, Ibrahim; Blumberg, Dan G.; Stern, Adrian

doi:10.1038/s41598-020-60413-8

Cited by 13 publications

(5 citation statements)

References 54 publications

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“…Although the application we report here focused on food control, the described approach can be implemented and used for any application simply by designing the characteristics of the passive filter and the tunable Lyot filter accordingly. Similar to our previous approach [8], this camera can also be used to give an image of all bands together as well as of each band separately. Other systems requiring more than one wavelength can benefit enormously from this type of filter [9][10].…”

Section: Discussionmentioning

confidence: 99%

Faster narrowband multi-spectral liquid crystal-based imaging modules tailored to the specific application

Pasha,

Abu Aisheh,

Abu Leil

et al. 2024

Liquid Crystals Optics and Photonic Devices

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The most common configuration of liquid crystal devices incorporated within spectral imaging systems is using LCTFs. Usually, these filters suffer from low light throughput or slow response times which may not meet the growing demands of industry and research. However, in most applications multispectral imaging is adequate, and no need for hyperspectral imaging. In this work, we implemented a discrete tunable Lyot-based filter in such systems to obtain spectral images more efficiently. The filter consists of 3 LC cells combined with 9 narrow bands of passive filter covering the VIS and NIR, which makes it a potential candidate for various applications. A system with a smaller number of bands designed for oximetry imaging is even faster and shows higher light throughput. Experimental results show that our system holds a relatively faster response time with high light throughput while providing reliable spectral information.

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Section: Discussionmentioning

confidence: 99%

Faster narrowband multi-spectral liquid crystal-based imaging modules tailored to the specific application

Pasha,

Abu Aisheh,

Abu Leil

et al. 2024

Liquid Crystals Optics and Photonic Devices

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“…As spectral encoding can be realized through many micro or nano light-modulating devices, BFRSM is very suitable for spectroscopy miniaturization. Various types of miniaturized spectrometer and spectral imaging devices have been developed based on BFRSM, such as film array-based spectrometers [ 4 , 5 , 6 ], quantum dot spectrometers [ 7 , 8 , 9 ], nanowire spectrometers [ 10 , 11 ], photonic crystal spectrometers and spectral imagers [ 12 , 13 , 14 ], and many other types of spectrometers and spectral imagers [ 15 , 16 , 17 , 18 , 19 , 20 ]. Moreover, as the detector for BFRSM acquires broadband spectral energy for each exposure, the optical throughput can be much higher than that of conventional dispersion-based spectrometers, so it is also broadly studied in remote sensing [ 21 , 22 ].…”

Section: Introductionmentioning

confidence: 99%

A Triangular-Matrix-Based Spectral Encoding Method for Broadband Filtering and Reconstruction-Based Spectral Measurement

Yue,

Wang

2024

Sensors

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Broadband filtering and reconstruction-based spectral measurement represent a hot technical route for miniaturized spectral measurement; the measurement encoding scheme has a great effect on the spectral reconstruction fidelity. The existing spectral encoding schemes are usually complex and hard to implement; thus, the applications are severely limited. Considering this, here, a simple spectral encoding method based on a triangular matrix is designed. The condition number of the proposed spectral encoding system is estimated and demonstrated to be relatively low theoretically; then, verification experiments are carried out, and the results show that the proposed encoding can work well under precise or unprecise encoding and measurement conditions; therefore, the proposed scheme is demonstrated to be an effective trade-off of the spectral encoding efficiency and implementation cost.

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“…Hyperspectral imaging provides a spectrum at each pixel in the image of a scene, providing rich color information of the scene. Much progress has been made in both hyperspectral imaging devices (Shmilovich et al, 2020) and their applications, such as photogrammetry (Mathys et al, 2019), pigment recognition (Cucci et al, 2011), and painting analysis (Cucci et al, 2013). Many of the applications require high spectral-resolution (2 nm bins or even shorter, according to (Cucci et al, 2013).…”

Section: Introductionmentioning

confidence: 99%

Eliminating Temporal Illumination Variations in Whisk-broom Hyperspectral Imaging

et al. 2022

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We propose a method for eliminating the temporal illumination variations in whisk-broom (point-scan) hyperspectral imaging. Whisk-broom scanning is useful for acquiring a spatial measurement using a pixel-based hyperspectral sensor. However, when it is applied to outdoor cultural heritages, temporal illumination variations become an issue due to the lengthy measurement time. As a result, the incoming illumination spectra vary across the measured image locations because different locations are measured at different times. To overcome this problem, in addition to the standard raster scan, we propose an additional perpendicular scan that traverses the raster scan. We show that this additional scan allows us to infer the illumination variations over the raster scan. Furthermore, the sparse structure in the illumination spectrum is exploited to robustly eliminate these variations. We quantitatively show that a hyperspectral image captured under sunlight is indeed affected by temporal illumination variations, that a Naïve mitigation method suffers from severe artifacts, and that the proposed method can robustly eliminate the illumination variations. Finally, we demonstrate the usefulness of the proposed method by capturing historic stained-glass windows of a French cathedral.

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Dual-camera design for hyperspectral and panchromatic imaging, using a wedge shaped liquid crystal as a spectral multiplexer

Cited by 13 publications

References 54 publications

Faster narrowband multi-spectral liquid crystal-based imaging modules tailored to the specific application

Faster narrowband multi-spectral liquid crystal-based imaging modules tailored to the specific application

A Triangular-Matrix-Based Spectral Encoding Method for Broadband Filtering and Reconstruction-Based Spectral Measurement

Eliminating Temporal Illumination Variations in Whisk-broom Hyperspectral Imaging

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