scholarly journals Underwater Spectral Imaging System Based on Liquid Crystal Tunable Filter

2021 ◽  
Vol 9 (11) ◽  
pp. 1206
Author(s):  
Hong Song ◽  
Syed Raza Mehdi ◽  
Chaopeng Wu ◽  
Zixin Li ◽  
Hai Gong ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Response ◽  
Image Data ◽  
Spectral Imaging ◽  
Tunable Filter ◽  
Test Analysis ◽  
Spectral Bands ◽  
Collecting Efficiency ◽  
Imaging Sensor

In the past decade, underwater spectral imaging (USI) has shown great potential in underwater exploration for its high spectral and spatial resolution. This proposal presents a stare-type USI system combined with the liquid crystal tunable filter (LCTF) spectral splitting device. Considering the working features of LCTF and the theoretical model of USI, the core structure containing “imaging lens-LCTF-imaging sensor” is designed and developed. The system is compact, and the optical geometry is constructed minimally. The spectral calibration test analysis proved that the spectral response range of the system covers a full band of 400 nm to 700 nm with the highest spectral resolution between 6.7 nm and 18.5 nm. The experiments show that the system can quickly collect high-quality spectral image data by switching between different spectral bands arbitrarily. The designed prototype provides a feasible and reliable spectral imaging solution for in situ underwater targets observation with high spectrum collecting efficiency.

Design and Calibration of Liquid Crystal Tunable Filter Based Spectral Imaging System

2012 ◽  
Author(s):  
Weilin Wang ◽  
Changying Li ◽  
Ernest W Tollner ◽  
Ronald D Gitaitis ◽  
Glen C Rains
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Imaging ◽  
Tunable Filter

scholarly journals Compressive spectral imaging system based on liquid crystal tunable filter

2018 ◽  
Vol 26 (19) ◽  
pp. 25226 ◽  
Author(s):  
Xi Wang ◽  
Yuhan Zhang ◽  
Xu Ma ◽  
Tingfa Xu ◽  
Gonzalo R. Arce
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Imaging ◽  
Tunable Filter

scholarly journals Miniature Compressive Ultra-spectral Imaging System Utilizing a Single Liquid Crystal Phase Retarder

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Isaac August ◽  
Yaniv Oiknine ◽  
Marwan AbuLeil ◽  
Ibrahim Abdulhalim ◽  
Adrian Stern
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Imaging ◽  
Crystal Phase ◽  
Liquid Crystal Phase

“Compact Spectral Imaging” System Using Liquid Crystal for Fast Measurement

1994 ◽  
Vol 1 (1) ◽  
pp. 129-131 ◽  
Author(s):  
Takashi INOUE ◽  
Akiko HlRAI ◽  
Kazuyoshi ITOH ◽  
Yoshiki ICHIOKA
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Imaging ◽  
Fast Measurement

scholarly journals Interference Spectral Imaging Based on Liquid Crystal Relaxation and Its Application in Optical Component Defect Detection

2022 ◽  
Vol 12 (2) ◽  
pp. 718
Author(s):  
Jiajia Yuan ◽  
Wei Fan ◽  
He Cheng ◽  
Dajie Huang ◽  
Tongyao Du
Keyword(s):  
Liquid Crystal ◽  
Imaging System ◽  
Spectral Imaging ◽  
Optical Path Difference ◽  
Path Difference ◽  
Optical Path ◽  
Hyperspectral Data ◽  
Optical Component ◽  
Path Delay ◽  
Polarized Beams

In this paper, we propose a fast interference spectral imaging system based on liquid crystal (LC) relaxation. The path delay of nematic LC during falling relaxation is used for the scanning of the optical path. Hyperspectral data can be obtained by Fourier transforming the data according to the path delay. The system can obtain two-dimensional spatial images of arbitrary wavelengths in the range of 300–1100 nm with a spectral resolution of 262 cm−1. Compared with conventional Fourier transform spectroscopy, the system can easily collect and integrate all valid information within 20 s. Based on the LC, controlling the optical path difference between two orthogonally polarized beams can avoid mechanical movement. Finally, the potential for application in contactless and rapid non-destructive optical component defect inspection is demonstrated.

scholarly journals Forgery Detection in a Questioned Hyperspectral Document Image using K-means Clustering

2020 ◽  
Author(s):  
Maria Yaseen ◽  
Rammal Aftab ◽  
Rimsha mahrukh
Keyword(s):  
Hyperspectral Imaging ◽  
Spectral Response ◽  
Document Image ◽  
Spectral Signature ◽  
Detection Techniques ◽  
Spectral Signatures ◽  
Spectral Bands ◽  
Mismatch Detection ◽  
The One ◽  
Imaging Sensor

Hyperspectral imaging allows for analysis of images in several hundred of spectral bands depending on the spectral resolution of the imaging sensor. Hyperspectral document image is the one which has been captured by a hyperspectral camera so that the document can be observed in the different bands on the basis of their unique spectral signatures. To detect the forgery in a document various Ink mismatch detection techniques based on hyperspectral imaging have presented vast potential in differentiating visually similar inks. Inks of different materials exhibit different spectral signature even if they have the same color. Hyperspectral analysis of document images allows identification and discrimination of visually similar inks. Based on this analysis forensic experts can identify the authenticity of the document. In this paper an extensive ink mismatch detection technique is presented which uses KMean Clustering to identify different inks on the basis of their unique spectral response and separates them into different clusters.

scholarly journals Forgery Detection in a Questioned Hyperspectral Document Image using K-means Clustering

2020 ◽  
Author(s):  
Maria Yaseen ◽  
Rammal Aftab ◽  
Rimsha mahrukh
Keyword(s):  
Hyperspectral Imaging ◽  
Spectral Response ◽  
Document Image ◽  
Spectral Signature ◽  
Detection Techniques ◽  
Spectral Signatures ◽  
Spectral Bands ◽  
Mismatch Detection ◽  
The One ◽  
Imaging Sensor

Hyperspectral imaging allows for analysis of images in several hundred of spectral bands depending on the spectral resolution of the imaging sensor. Hyperspectral document image is the one which has been captured by a hyperspectral camera so that the document can be observed in the different bands on the basis of their unique spectral signatures. To detect the forgery in a document various Ink mismatch detection techniques based on hyperspectral imaging have presented vast potential in differentiating visually similar inks. Inks of different materials exhibit different spectral signature even if they have the same color. Hyperspectral analysis of document images allows identification and discrimination of visually similar inks. Based on this analysis forensic experts can identify the authenticity of the document. In this paper an extensive ink mismatch detection technique is presented which uses KMean Clustering to identify different inks on the basis of their unique spectral response and separates them into different clusters.

The Study on Spectral Imaging Technique in Detection of Dermatosis

2012 ◽  
Vol 472-475 ◽  
pp. 879-882
Author(s):  
Yan Ping Chen ◽  
Jiao Dai ◽  
Ling Hua Kong ◽  
Chun Bin Li
Keyword(s):  
Liquid Crystal ◽  
Skin Disease ◽  
Multispectral Imaging ◽  
Imaging Technique ◽  
Spectral Imaging ◽  
Cost Effective ◽  
Tunable Filter ◽  
Human Beings ◽  
Imaging Technology ◽  
Filter Wheel

Dermatosis, a kind of common and frequent disease, is harmful to health and risk against the lives of human beings. The detection of dermatosis is of great significance, especially to the early diagnosis of skin disease. Nowadays, the studies of spectral imaging technology in the diagnosis of skin disease are attracting more and more attentions. In this paper, we firstly review some literary products related to dermatosis detection and then make a comparison among fluorescence spectrum method, filter wheel method, liquid crystal tunable filter (LCTF) method and mosaic multispectral imaging technology. Finally we propose that the smaller, lighter and more cost-effective equipment should be the trend.

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