Single-shot multispectral imager using spatially multiplexed Fourier spectral filters

Ni, Chuan; Jia, Jie; Howard, Matthew; Hirakawa, Keigo; Sarangan, Andrew

doi:10.1364/josab.35.001072

Cited by 6 publications

(3 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Another issue is the "chromatic aberration" effect along channels which results in blur. Snapshot multispectral cameras also face the same problem [25]. In filter-wheel multispectral camera, this issue is resolved by focusing the lens for each channel individually and then combining the resulting images to ensure that the images for each channel are as sharp as possible.…”

Section: Image Acquisitionmentioning

confidence: 99%

Multispectral camera as spatio-spectrophotometer under uncontrolled illumination

Khan¹,

Thomas²,

Hardeberg³

et al. 2019

Opt. Express

View full text Add to dashboard Cite

Multispectral constancy enables the illuminant invariant representation of multispectral data. This article proposes an experimental investigation of multispectral constancy through the use of multispectral camera as a spectrophotometer for the reconstruction of surface reflectance. Three images with varying illuminations are captured and the spectra of material surfaces is reconstructed. The acquired images are transformed into canonical representation through the use of diagonal transform and spectral adaptation transform. Experimental results show that use of multispectral constancy is beneficial for both filter-wheel and snapshot multispectral cameras. The proposed concept is robust to errors in illuminant estimation and is able to perform well with linear spectral reconstruction method. This work makes us one step closer to the use of multispectral imaging for computer vision.

show abstract

Section: Image Acquisitionmentioning

confidence: 99%

Multispectral camera as spatio-spectrophotometer under uncontrolled illumination

Khan¹,

Thomas²,

Hardeberg³

et al. 2019

Opt. Express

View full text Add to dashboard Cite

show abstract

“…CMOS cameras) 3,4 in order to spatially separate the spectral content of the incident light into narrowband measurements. In an earlier work, we introduced the concept of Fourier filters, 5,6 where broadband sinusoidally varying spectral filters are used to resolve the spectral content of light with a high overall transmission compared to narrow band filters. When detecting narrowband spectral features (such as emmission bands) these filters were shown to require fewer number of filters compared to the conventional narrowband measurements.…”

Section: Introductionmentioning

confidence: 99%

Single-shot spectroscopy using continuously variable filters

Lawandi,

Bolatbek,

Agha

et al. 2023

Nanoengineering: Fabrication, Properties, Optics, Thin Films, and Devices XX

Self Cite

View full text Add to dashboard Cite

Spectroscopic measurements are used in increasingly diverse areas of manufacturing, disease detection, food quality inspection, indoor lighting control, etc. Commonly used spectral decomposition methods utilize several discrete dispersive optical elements to split the incoming light into its frequency components and direct them onto a linear photodetector array. In our previous work, we demonstrated that such mechanically fragile systems can be replaced by thin film dielectric Fourier spectral filters. However, the main disadvantage of this technique is the need for multiple filters with varying dielectric Fabry-Perot cavity lengths, which requires extensive fabrication processes to lithographically pattern and etch. In this work, we demonstrate a novel fabrication of a continuously variable filter, using glancing angle deposition, that can produce 10× more Fourier filters in a single deposition run without the need for lithographic patterning. We apply this method to a commercial off-the-shelf 38-channel linear photodetector array and demonstrate the ability to quickly decompose the incoming signal using only half of the available channels. This novel technique has the potential to enable highly compact and highly robust spectrometers that could be integrated into many handheld devices

show abstract

“…Several snapshot devices are proposed in the literature [4] to increase the number of channels and thus the accuracy of the camera systems. Some devices benefit from optimized filter designs [5,6]. Some designs are simply extensions of RGB cameras with additional sensors, color filter arrays (CFA), filter wheels, or beam-splitters [7,8].…”

Section: Introductionmentioning

confidence: 99%

Configuration and Registration of Multi-Camera Spectral Image Database of Icon Paintings

Mirhashemi

2019

Computation

View full text Add to dashboard Cite

At the cost of added complexity and time, hyperspectral imaging provides a more accurate measure of the scene’s irradiance compared to an RGB camera. Several camera designs with more than three channels have been proposed to improve the accuracy. The accuracy is often evaluated based on the estimation quality of the spectral data. Currently, such evaluations are carried out with either simulated data or color charts to relax the spatial registration requirement between the images. To overcome this limitation, this article presents an accurately registered image database of six icon paintings captured with five cameras with different number of channels, ranging from three (RGB) to more than a hundred (hyperspectral camera). Icons are challenging topics because they have complex surfaces that reflect light specularly with a high dynamic range. Two contributions are proposed to tackle this challenge. First, an imaging configuration is carefully arranged to control the specular reflection, confine the dynamic range, and provide a consistent signal-to-noise ratio for all the camera channels. Second, a multi-camera, feature-based registration method is proposed with an iterative outlier removal phase that improves the convergence and the accuracy of the process. The method was tested against three other approaches with different features or registration models.

show abstract

Single-shot multispectral imager using spatially multiplexed Fourier spectral filters

Cited by 6 publications

References 15 publications

Multispectral camera as spatio-spectrophotometer under uncontrolled illumination

Multispectral camera as spatio-spectrophotometer under uncontrolled illumination

Single-shot spectroscopy using continuously variable filters

Configuration and Registration of Multi-Camera Spectral Image Database of Icon Paintings

Contact Info

Product

Resources

About