A novel snapshot polarimetric imager

Wong, Gerald; McMaster, Ciaran; Struthers, Robert; Gorman, Alistair; Sinclair, Peter M.; Lamb, Robert A.; Harvey, Andrew R.

doi:10.1117/12.974824

Cited by 5 publications

(5 citation statements)

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“…Thus both polarisation states are recorded simultaneously and there is no latency. Once the images have been accurately registered [5,6] there is a simple one-to-one pixel correlation between identical parts of the two images. The passenger plane is approximately 5km away and the sub-images have been normalised for clarity.…”

Section: Resultsmentioning

confidence: 99%

“…where H s and V s are the signal values recorded by corresponding pixels within the two images for the two polarisations [6]. Figure 8 clearly shows polarimetric variation with wavelength and position and that this variation is different for two cars.…”

Section: B Combined Polarimetric and Multispectral Imagingmentioning

confidence: 95%

“…The variation in polarimetric signature was determined by calculating the polarimetric contrast defined by equation (3). The sequence of the side-by-side red Audi and dark blue Ford shown in figure 6 was processed using the algorithm designed for polarimetric analysis outlined in [6]. The corresponding frames of the processed video are shown in figure 10, where green is used to highlight horizontally polarised light and red is used vertically polarised light.…”

Section: B Combined Polarimetric and Multispectral Imagingmentioning

confidence: 99%

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Computational polarimetric and multispectral imaging with a variable filter mask

Wong¹,

McMaster²,

Pilkington³

et al. 2013

2013 Saudi International Electronics, Communications and Photonics Conference

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We report on progress made in developing a polarimetric and multispectral imaging (MSI) camera that uses a coded filter mask to record spectral data on either a single frame or only a few frames depending on the design of the mask and the application. The design uses commercially available variable filters and beamsplitters to record spectral data simultaneously on a focal plane array, thus negating the need for scanning mechanisms or dispersive optical elements. The data rate depends on the design of the filter mask, pixel resolution, relative motion between target and camera, and the frame rate. The polarimetric data is recorded on a single frame thus eliminating latency. Multispectral data may be recorded on a few frames or a single frame, thus reducing the need for many multi-frame acquisitions. An optimum mask design matched to the imaging lens and focal plane array resolution, allows an object to be detected against spectral clutter or background on a single pixel. Thus a spatially resolved image is not required, alleviating the need for high magnification which would be a practical limitation where compact optical systems are required.The proof-of-principle is reported that uses a 1D variable filter mask to provide spectra of resolved target images in the near field for the visible spectrum. Test data are presented that show the potential for the concept and how it is readily extended to use a 2D mask in a modified design.

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Section: Resultsmentioning

confidence: 99%

Section: B Combined Polarimetric and Multispectral Imagingmentioning

confidence: 95%

Section: B Combined Polarimetric and Multispectral Imagingmentioning

confidence: 99%

See 1 more Smart Citation

Computational polarimetric and multispectral imaging with a variable filter mask

Wong¹,

McMaster²,

Pilkington³

et al. 2013

2013 Saudi International Electronics, Communications and Photonics Conference

Self Cite

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“…The amplitude-division polarization imaging system places multiple polarization modulation elements in parallel at the rear end of the spectroscopic prism, and then utilizes multiple lens groups to achieve a separate focusing for each channel with a single detector or multiple detectors. Finally, it can capture either a single image with different polarization states or multiple images corresponding to different polarization states 4,5 . A micropolarizer filters array is fabricated at the pixel level and positioned in front of the photosensitive sensors, in order to establish a division of focal plane type polarimetric camera.…”

Section: Introductionmentioning

confidence: 99%

Design of polarimetric camera based on the single-layer twisted nematic liquid crystal device

ye,

zhu,

liu

et al. 2024

MIPPR 2023: Multispectral Image Acquisition, Processing, and Analysis

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Polarization is the asymmetry of a light wave's electric field vibration direction with respect to its propagation direction, as a crucial clue for describing the light, which is one of the most apparent signs that distinguishes transverse waves from longitudinal waves. The current mainstream polarimetric cameras typically adopt a division of focal plane imaging architecture, in which a metal wire-grid structure is coupled with a detector to acquire the polarization state of the target. However, the structure of the division of focal plane reduces effective spatial resolution of the detector and requires complex registration algorithms to achieve pixel-level polarization acquisition, which leads to high equipment costs and impedes the development and application of polarimetric cameras in industrial production. In this paper, a single-layer twisted nematic liquid crystal (TNLC) is inserted to the imaging optical path of traditional camera to realize the polarization acquisition, allowing for a cost-effective transition from traditional devices to polarization imaging systems. The imaging detector coupled with the TNLC device can acquire polarization states ranging from 10 to 90-degree by adjusting the external voltage applied on the LC device. Moreover, a polarization angle calibration method based on a single-layer TNLC is proposed in this paper, providing a reliable reference for electrically controlled polarization angle acquisition. The experimental results acquired by presented imaging system demonstrate the feasibility and effectiveness of the proposed method. The TNLC based imaging scheme presented in this paper provides a solid foundation for developing simple, low-cost, and efficient polarimetric cameras.

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“…However, it has long been recognised that additional analysis of polarisation state, governed by the material refractive index, surface orientation and angle of observation, can lead to better discrimination. False colour representations of the polarimetric data can visually reveal hidden targets [148] and to some extent, 3D structure [149]. By exploiting knowledge about the dependence of polarisation state on surface and viewing angle, and the fixed vehicle to road geometry, Connor et al…”

Section: Introductionmentioning

confidence: 99%

300 GHz radar object recognition based on deep neural networks and transfer learning

Sheeny

Wallace

Wang

2020

IET Radar, Sonar & Navigation

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A novel snapshot polarimetric imager

Cited by 5 publications

References 0 publications

Computational polarimetric and multispectral imaging with a variable filter mask

Computational polarimetric and multispectral imaging with a variable filter mask

Design of polarimetric camera based on the single-layer twisted nematic liquid crystal device

300 GHz radar object recognition based on deep neural networks and transfer learning

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