scholarly journals Probability of correct reconstruction in compressive spectral imaging

2016 ◽  
Vol 36 (2) ◽  
pp. 68 ◽  
Author(s):  
Samuel Eduardo Pinilla ◽  
Héctor Miguel Vargas García ◽  
Henry Arguello Fuentes
Keyword(s):  
Image Reconstruction ◽  
Spectral Imaging ◽  
Reconstruction Algorithm ◽  
Data Cube ◽  
Coded Aperture ◽  
Sensing Matrix ◽  
3 Dimensional ◽  
3D Data ◽  
Minimum Number

Coded Aperture Snapshot Spectral Imaging (CASSI) systems capture the 3-dimensional (3D) spatio-spectral information of a scene using a set of 2-dimensional (2D) random coded Focal Plane Array (FPA) measurements. A compressed sensing reconstruction algorithm is then used to recover the underlying spatio-spectral 3D data cube. The quality of the reconstructed spectral images depends exclusively on the CASSI sensing matrix, which is determined by the statistical structure of the coded apertures. The Restricted Isometry Property (RIP) of the CASSI sensing matrix is used to determine the probability of correct image reconstruction and provides guidelines for the minimum number of FPA measurement shots needed for image reconstruction. Further, the RIP can be used to determine the optimal structure of the coded projections in CASSI. This article describes the CASSI optical architecture and develops the RIP for the sensing matrix in this system. Simulations show the higher quality of spectral image reconstructions when the RIP property is satisfied. Simulations also illustrate the higher performance of the optimal structured projections in CASSI.

scholarly journals High-dynamic range compressive spectral imaging by grayscale coded aperture adaptive filtering

2015 ◽  
Vol 35 (3) ◽  
pp. 53-60 ◽  
Author(s):  
Nelson Eduardo Diaz ◽  
Hoover Fabian Rueda Chacon ◽  
Henry Arguello Fuentes
Keyword(s):  
Dynamic Range ◽  
Imaging System ◽  
Three Dimensional ◽  
Spectral Imaging ◽  
Reconstruction Algorithm ◽  
High Dynamic Range ◽  
Data Cube ◽  
Coded Aperture ◽  
Coded Apertures

<p class="p1">The coded aperture snapshot spectral imaging system (CASSI) is an imaging architecture which senses the three dimensional informa-tion of a scene with two dimensional (2D) focal plane array (FPA) coded projection measurements. A reconstruction algorithm takes advantage of the compressive measurements sparsity to recover the underlying 3D data cube. Traditionally, CASSI uses block-un-block coded apertures (BCA) to spatially modulate the light. In CASSI the quality of the reconstructed images depends on the design of these coded apertures and the FPA dynamic range. This work presents a new CASSI architecture based on grayscaled coded apertu-res (GCA) which reduce the FPA saturation and increase the dynamic range of the reconstructed images. The set of GCA is calculated in a real-time adaptive manner exploiting the information from the FPA compressive measurements. Extensive simulations show the attained improvement in the quality of the reconstructed images when GCA are employed.  In addition, a comparison between traditional coded apertures and GCA is realized with respect to noise tolerance.</p>

scholarly journals Rotational hyperspectral scanner and related image reconstruction algorithm

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Longqiang Luo ◽  
Shuo Li ◽  
Xinli Yao ◽  
Sailing He
Keyword(s):  
Image Reconstruction ◽  
Spectral Resolution ◽  
Reconstruction Algorithm ◽  
Hyperspectral Data ◽  
Data Cube ◽  
Spatial Accuracy ◽  
Scanning Method ◽  
Image Reconstruction Algorithm

AbstractWe design and implement a compact and lightweight hyperspectral scanner. Based on this, a novel rotational hyperspectral scanner was demonstrated. Different from translational scanning, rotational scanning is a moveless and stable scanning method. We also designed a relevant image algorithm to reconstruct the image from an angular recorded hyperspectral data cube. The algorithm works well even with uncertain radial and tangential offset, which is caused by mechanical misalignment. The system shown a spectral resolution of 5 nm after calibration. Finally, spatial accuracy and spectral precision were discussed, based on some additional experiments.

scholarly journals In situX-ray beam imaging using an off-axis magnifying coded aperture camera system

2013 ◽  
Vol 20 (4) ◽  
pp. 596-602 ◽  
Author(s):  
Anton Kachatkou ◽  
Nicholas Kyele ◽  
Peter Scott ◽  
Roelof van Silfhout
Keyword(s):  
Image Reconstruction ◽  
Impulse Response ◽  
Finite Thickness ◽  
Incident Beam ◽  
Reconstruction Algorithm ◽  
Coded Aperture ◽  
X Ray ◽  
Image Reconstruction Algorithm ◽  
Imaging Model ◽  
Image Blur

An imaging model and an image reconstruction algorithm for a transparent X-ray beam imaging and position measuring instrument are presented. The instrument relies on a coded aperture camera to record magnified images of the footprint of the incident beam on a thin foil placed in the beam at an oblique angle. The imaging model represents the instrument as a linear system whose impulse response takes into account the image blur owing to the finite thickness of the foil, the shape and size of camera's aperture and detector's point-spread function. The image reconstruction algorithm first removes the image blur using the modelled impulse response function and then corrects for geometrical distortions caused by the foil tilt. The performance of the image reconstruction algorithm was tested in experiments at synchrotron radiation beamlines. The results show that the proposed imaging system produces images of the X-ray beam cross section with a quality comparable with images obtained using X-ray cameras that are exposed to the direct beam.

scholarly journals Augmented Reality Character Topeng Malang Dewi as an Effort to Improve the Quality of Student Learning Media

2021 ◽  
Author(s):  
Moch. Heru Eriza ◽  
Andy Pramono ◽  
Dimas Rifqi Novica
Keyword(s):  
Augmented Reality ◽  
Research Method ◽  
Development Research ◽  
Subdivision Surface ◽  
3 Dimensional ◽  
Character Design ◽  
Minimum Number ◽  
Artistic Heritage ◽  
Surface Technique

The preservation of the cultural and artistic heritage of our ancestors is important for us to persevere as a species. The purpose of this research was to introduce Indonesian culture, especially Topeng Malang, to the Indonesian society, particularly the teenagers, using 3D character media, implemented through augmented reality. The study followed the development research method of Borg WR and Gall MD. 3D characters were designed using the low poly subdivision surface technique, with a minimum number of poly but maintaining the detail of the character. Based on the results of the data analysis, the following essential points were obtained: (1) The character design of the Topeng Malang adopted the figures of Dewi Sekartaji and Dewi Walangwati. (2) The character design of the Topeng Malang character represented the posture, nature, and characteristics of the style. The result of this design was the implementation of 3-dimensional masks and character transformation in augmented reality media. Based on the results and the questionnaires used by the author to gather users’ knowledge of the character shape of the augmented reality media of the mask, 49.3% of the responses were found to be very good and 46.4% good. These results certainly add to the positive values of utilizing the 3D character media as a medium to introduce Wayang Topeng Malangan. Keywords: Topeng Malang, 3D character model

scholarly journals Plane wave ultrasound imaging using synthetic aperture image reconstruction techniques

2021 ◽  
Author(s):  
Dae-Myoung (Danny) Yang
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Plane Wave ◽  
Ultrasound Imaging ◽  
Plane Waves ◽  
Reconstruction Algorithm ◽  
Synthetic Aperture ◽  
Depth Of Penetration ◽  
Image Reconstruction Techniques

Ultrasound imaging based on transmitting plane waves (PW) enables ultrafast imaging. Coherent PW compounding ultrasound imaging can reach the image quality of optimal multifocus image. In the image reconstruction, it was assumed that an infinite extent PWs was emitted. In this thesis, we propose a new image reconstruction algorithm – Synthetic-aperture plane-wave (SAPW) imaging – without using this assumption. The SAPW imaging was compared with the PWs imaging in numerical simulations and experimental measurements. The measured RF data in PW imaging was first decoded in the frequency domain using a pseudoinverse algorithm to estimate the RF data Then, SAPW RF data were used to reconstruct images through the standard synthetic transit aperture (STA) method. Main improvements in the image quality of the SAPW imaging in comparison with the PWs imaging are increases in the depth of penetration and the field of view when contrast-to-noise ratio (CNR) was used as a quantitative metric.

scholarly journals Plane wave ultrasound imaging using synthetic aperture image reconstruction techniques

2021 ◽  
Author(s):  
Dae-Myoung (Danny) Yang
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Plane Wave ◽  
Ultrasound Imaging ◽  
Plane Waves ◽  
Reconstruction Algorithm ◽  
Synthetic Aperture ◽  
Depth Of Penetration ◽  
Image Reconstruction Techniques

Ultrasound imaging based on transmitting plane waves (PW) enables ultrafast imaging. Coherent PW compounding ultrasound imaging can reach the image quality of optimal multifocus image. In the image reconstruction, it was assumed that an infinite extent PWs was emitted. In this thesis, we propose a new image reconstruction algorithm – Synthetic-aperture plane-wave (SAPW) imaging – without using this assumption. The SAPW imaging was compared with the PWs imaging in numerical simulations and experimental measurements. The measured RF data in PW imaging was first decoded in the frequency domain using a pseudoinverse algorithm to estimate the RF data Then, SAPW RF data were used to reconstruct images through the standard synthetic transit aperture (STA) method. Main improvements in the image quality of the SAPW imaging in comparison with the PWs imaging are increases in the depth of penetration and the field of view when contrast-to-noise ratio (CNR) was used as a quantitative metric.

scholarly journals Development of a simple, portable, colorimetric arsenic sensor based on Molybdenum Blue Chemistry

2021 ◽  
Author(s):  
Nevetha Yogarajah
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Ultrasound Imaging ◽  
Plane Waves ◽  
Reconstruction Algorithm ◽  
Depth Of Penetration ◽  
Molybdenum Blue ◽  
Ultrafast Imaging ◽  
Infinite Extent

Ultrasound imaging based on transmitting plane waves (PW) enables ultrafast imaging. Coherent PW compounding ultrasound imaging can reach the image quality of optimal multifocus image. In the image reconstruction, it was assumed that an infinite extent PWs was emitted. In this thesis, we propose a new image reconstruction algorithm – Synthetic-aperture plane-wave (SAPW) imaging – without using this assumption. The SAPW imaging was compared with the PWs imaging in numerical simulations and experimental measurements. The measured RF data in PW imaging was first decoded in the frequency domain using a pseudoinverse algorithm to estimate the RF data Then, SAPW RF data were used to reconstruct images through the standard synthetic transit aperture (STA) method. Main improvements in the image quality of the SAPW imaging in comparison with the PWs imaging are increases in the depth of penetration and the field of view when contrast-to-noise ratio (CNR) was used as a quantitative metric

scholarly journals Development of a simple, portable, colorimetric arsenic sensor based on Molybdenum Blue Chemistry

2021 ◽  
Author(s):  
Nevetha Yogarajah
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Ultrasound Imaging ◽  
Plane Waves ◽  
Reconstruction Algorithm ◽  
Depth Of Penetration ◽  
Molybdenum Blue ◽  
Ultrafast Imaging ◽  
Infinite Extent

Ultrasound imaging based on transmitting plane waves (PW) enables ultrafast imaging. Coherent PW compounding ultrasound imaging can reach the image quality of optimal multifocus image. In the image reconstruction, it was assumed that an infinite extent PWs was emitted. In this thesis, we propose a new image reconstruction algorithm – Synthetic-aperture plane-wave (SAPW) imaging – without using this assumption. The SAPW imaging was compared with the PWs imaging in numerical simulations and experimental measurements. The measured RF data in PW imaging was first decoded in the frequency domain using a pseudoinverse algorithm to estimate the RF data Then, SAPW RF data were used to reconstruct images through the standard synthetic transit aperture (STA) method. Main improvements in the image quality of the SAPW imaging in comparison with the PWs imaging are increases in the depth of penetration and the field of view when contrast-to-noise ratio (CNR) was used as a quantitative metric

Difference Spectrum Images: Numerical Filters Applied to EELS 3D Data Sets

2001 ◽  
Vol 7 (S2) ◽  
pp. 1160-1161
Author(s):  
G. Kothleitner ◽  
F. Hofer ◽  
C. Trevor
Keyword(s):  
Energy Loss ◽  
Imaging Techniques ◽  
Difference Spectrum ◽  
Data Cube ◽  
Data Sets ◽  
3 Dimensional ◽  
Energy Filtering ◽  
3D Data ◽  
Transmission Electron ◽  
Image Pixels

Spectroscopy and imaging techniques based on electron energy-losses (EELS) in a TEM have proven to be important tools to characterize materials and life science samples. There are two techniques available to explore the energy-loss dimension. in the fixed-beam approach spectroscopic data are recorded via energy-filtered images taken by an energy-filtering transmission electron microscope (EFTEM). in the STEM approach a parallel-detection EELS spectrometer (PEELS) coupled with a small focused probe acquires large energy ranges of the energy-loss spectrum point-wise for a small area. Both techniques produce complete 3 dimensional data sets containing energy-loss information for all image pixels. This technique is called EFTEM or STEM spectrum imaging.In the recorded SI data cube the x and y-axes correspond to spatial positions in the specimen as for any image. The third axis contains the energy-loss spectrum. in the scanning mode one records a complete spectrum for each pixel.

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