scholarly journals Applying Speckle Noise Suppression to Refractive Indices Change Detection in Porous Silicon Microarrays

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2975
Author(s):  
Ruyong Ren ◽  
Zhenhong Jia ◽  
Jie Yang ◽  
Nikola Kasabov
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Change Detection ◽  
Noise Suppression ◽  
Refractive Index Change ◽  
Speckle Noise ◽  
Detection Accuracy ◽  
Value Change ◽  
Nonlocal Means ◽  
Index Changes

The gray value method can be used to detect gray value changes of each unit almost parallel to the surface image of PSi (porous silicon) microarrays and indirectly measure the refractive index changes of each unit. However, the speckles of different noise intensities produced by lasers on a porous silicon surface have different effects on the gray value of the measured image. This results in inaccurate results of refractive index changes obtained from the change in gray value. Therefore, it is very important to reduce the influence of speckle noise on measurement results. In this paper, a new algorithm based on the concepts of probability-based nonlocal-means filtering (PNLM), gradient operator, and median filtering is proposed for gray value restoration of porous silicon microarray images. A good linear relationship between gray value change and refractive index change is obtained, which can reduce the influence of speckle noise on the gray value of the PSi microarray image, improving detection accuracy. This means the method based on gray value change detection can be applied to the biological detection of PSi microarray arrays.

scholarly journals Speckle Noise Removal in Image-based Detection of Refractive Index Changes in Porous Silicon Microarrays

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ruyong Ren ◽  
Zhiqing Guo ◽  
Zhenhong Jia ◽  
Jie Yang ◽  
Nikola K. Kasabov ◽  
...  
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Refractive Index Change ◽  
Speckle Noise ◽  
Noise Removal ◽  
Detection Sensitivity ◽  
Gray Level ◽  
Denoising Method ◽  
Index Changes ◽  
Gray Values

Abstract Based on porous silicon (PSi) microarray images, we propose a new method called the phagocytosis algorithm (PGY) for removing the influence of speckle noise on image gray values. In a theoretical analysis, speckle noise of different intensities is added to images, and a suitable denoising method is developed to restore the image gray level. This method can be used to reduce the influence of speckle noise on the gray values of PSi microarray images to improve the accuracy of detection and increase detection sensitivity. In experiments, the method is applied to detect refractive index changes in PSi microcavity images, and a good linear relationship between the gray level change and the refractive index change is obtained. In addition, the algorithm is applied to a PSi microarray image, and good results are obtained.

scholarly journals Image Processing of Porous Silicon Microarray in Refractive Index Change Detection

Sensors ◽  
2017 ◽  
Vol 17 (6) ◽  
pp. 1335 ◽  
Author(s):  
Zhiqing Guo ◽  
Zhenhong Jia ◽  
Jie Yang ◽  
Nikola Kasabov ◽  
Chuanxi Li
Keyword(s):  
Image Processing ◽  
Refractive Index ◽  
Porous Silicon ◽  
Change Detection ◽  
Refractive Index Change ◽  
Index Change

Refractive index change detection based on porous silicon microarray

2016 ◽  
Vol 122 (5) ◽  
Author(s):  
Weirong Chen ◽  
Zhenhong Jia ◽  
Peng Li ◽  
Guodong Lv ◽  
Xiaoyi Lv
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Change Detection ◽  
Refractive Index Change ◽  
Index Change

scholarly journals Significant photoinduced refractive index change observed in porous silicon Fabry–Pérot resonators

2000 ◽  
Vol 76 (15) ◽  
pp. 1990-1992 ◽  
Author(s):  
Morio Takahashi ◽  
Yuichi Toriumi ◽  
Takahiro Matsumoto ◽  
Yasuaki Masumoto ◽  
Nobuyoshi Koshida
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Refractive Index Change ◽  
Index Change ◽  
Fabry Perot

scholarly journals Flow-Through Self-Standing Porous Silicon Sensor

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 17
Author(s):  
David Martín-Sánchez ◽  
Salvador Ponce-Alcántara ◽  
Jaime García-Rupérez
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Multilayer Structure ◽  
Reflectance Spectra ◽  
Flow Through ◽  
Index Changes ◽  
Lift Off ◽  
Theoretical Simulations ◽  
Silicon Sensor ◽  
Good Agreement

A self-standing porous silicon (PS) multilayer structure detached from the substrate by the lift-off method and integrated with a microfluidic cell is presented. Experiments of refractive index changes sensing flow through open-ended pores are reported. We continuously recorded the reflectance spectra of the PS membrane each 30 s and measured the shift as different substances flowed through the structure. The experimental sensitivity values are in good agreement with the theoretical simulations performed.

scholarly journals Parallel Detection of Refractive Index Changes in a Porous Silicon Microarray Based on Digital Images

Sensors ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 750 ◽  
Author(s):  
Chuanxi Li ◽  
Zhenhong Jia ◽  
Peng Li ◽  
Hao Wen ◽  
Guodong Lv ◽  
...  
Keyword(s):  
Refractive Index ◽  
Porous Silicon ◽  
Digital Images ◽  
Parallel Detection ◽  
Index Changes

AN APPROACH FOR IMPROVING ACCURACY OF CHANGE DETECTION IN MULTI-TEMOPRAL SAR IMAGES

2020 ◽  
pp. 47-54
Author(s):  
Nguyen Hung An
Keyword(s):  
Change Detection ◽  
Natural Resource ◽  
Speckle Noise ◽  
Sea Surface ◽  
Detection Accuracy ◽  
Sar Images ◽  
Novel Approach ◽  
Multi Temporal ◽  
Improving Accuracy

Algorithms of change detection in multi-temporal SAR images have received great interests for recent decades, and been widely applied in natural resource supervision activities. However, these algorithms still expose the limitation of detection accuracy due to inhenrent presence of speckle noise in SAR images. This paper developed a novel approach of change detection in multi-temporal SAR images of sea surface. The algorithm has increased accuracy of change detection in multi-temporal SAR images of sea surface compared with recent other methods.

ANALYSIS OF OPTICALLY INDUCED REFRACTIVE INDEX CHANGE OF DYE-DOPED NEMATIC LIQUID CRYSTALS

2002 ◽  
Vol 11 (01) ◽  
pp. 1-12 ◽  
Author(s):  
A. SHISHIDO ◽  
M.-Y. SHIH ◽  
I. C. KHOO
Keyword(s):  
Refractive Index ◽  
Liquid Crystals ◽  
Diffraction Efficiency ◽  
Order Parameter ◽  
Nematic Liquid Crystals ◽  
Refractive Index Change ◽  
Beam Polarization ◽  
Methyl Red ◽  
Parameter Modification ◽  
Index Changes

We present a detailed quantitative experimental and theoretical study of laser induced refractive index changes in nematic liquid crystals doped with methyl-red, disperse red and azobenzene liquid crystal. These refractive index changes, originating from molecular reorientations and order parameter modification, are measured by means of intensity and polarization grating methods. The reorientation of the director axis is calculated from polarization dependence of the probe beam diffraction efficiency. The contribution of each effect to the total diffraction efficiency is quantitatively evaluated. In general, we found that the reorientational direction of the NLC molecules depends on the dopants as well as the nature of the pump beam polarization state. In methyl-red doped samples, the laser induced reorientation mechanism dominates, whereas order parameter modification plays a major role in the others.

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