We investigate the problems of 1-D and 2-D signal recovery from subsampled Hadamard measurements using Haar wavelet as a sparsity inducing prior. These are interest in, e.g., computational imaging applications relying on optical multiplexing or single-pixel imaging. However, realization such modalities is often hindered by coherence between bases. The variable multilevel density sampling strategies solve this issue adjusting subsampling process to local coherence, respectively, two bases;...

Abstract Here we show that compressive sensing allows 4‐dimensional (4‐D) STEM data to be obtained and accurately reconstructed with both high‐speed reduced electron fluence. The methodology needed achieve these results compared conventional 4‐D approaches requires only a random subset of probe locations is acquired from the typical regular scanning grid, which immediately generates higher speed lower fluence experimentally. We also consider downsampling detector, showing oversampling...

This paper focuses on the estimation of low-complexity signals when they are observed through $M$ uniformly quantized compressive observations. Among such signals, we consider 1-D sparse vectors, low-rank matrices, or compressible that well approximated by one these two models. In this context, prove efficiency a variant Basis Pursuit Denoise, called Consistent (CoBP), enforcing consistency between observations and re-observed estimate, while promoting its nature. We show reconstruction...

Abstract Traditional image acquisition for cryo focused ion-beam scanning electron microscopy (FIB-SEM) tomography often sees thousands of images being captured over a period many hours, with immense data sets produced. When imaging beam sensitive materials, these are compromised by additional constraints related to damage and the devitrification material during imaging, which renders both costly unreliable. Subsampling inpainting proposed as solutions aspects, allowing fast low-dose take...

Abstract Electron backscatter diffraction (EBSD) has developed over the last few decades into a valuable crystallographic characterisation method for wide range of sample types. Despite these advances, issues such as complexity preparation, relatively slow acquisition, and damage in beam‐sensitive samples, still limit quantity quality interpretable data that can be obtained. To mitigate issues, here we propose based on subsampling probe positions subsequent reconstruction an incomplete set....

Four-dimensional Scanning Transmission Electron Microscopy (4D STEM) with data acquired using a defocused electron probe is promising tool for characterising complex biological specimens and materials through phase retrieval process known as Ptychography (EP). The efficacy of 4D STEM acquisition the resulting quality EP reconstruction depends on overlap ratio adjacent illuminated areas. This paper demonstrates how impacts redundancy reconstruction. We define two quantities function that are...

Phase reconstruction is important in transmission electron microscopy for structural studies. We describe Fourier ptychography and its application to phase of both radiation-resistant beam-sensitive materials. demonstrate that the exit wave can be reconstructed at high resolution using a modified iterative retrieval algorithm with data collected an alternative optical geometry. This method achieves spatial 0.63 nm fluence $4.5 \times 10^2 \, e^-/\text{nm}^2$, as validated on Cry11Aa protein...

Images and spectra obtained from aberration corrected scanning transmission electron microscopes (STEM) are now used routinely to quantify the morphology, structure, composition, chemistry, bonding, optical/electronic properties of nanostructures, interfaces, defects in many materials/biological systems. However, obtaining quantitative reproducible atomic resolution observations some experiments is actually harder with these ground-breaking instrumental capabilities, as increase beam current...

Despite the widespread use of Scanning Transmission Electron Microscopy (STEM) for observing structure materials at atomic scale, a detailed understanding some relevant electron beam damage mechanisms is limited. Recent reports suggest that certain types can be modelled as diffusion process and accumulation effects this must kept low in order to reduce damage. We therefore develop an explicit mathematical formulation spatiotemporal processes STEM take into account both instrument sample...

Scanning transmission electron microscopy images can be complex to interpret on the atomic scale as contrast is sensitive multiple factors such sample thickness, composition, defects and aberrations. Simulations are commonly used validate or real experimental images, but they come at a cost of either long computation times specialist hardware graphics processing units. Recent works in compressive sensing for STEM have shown that it possible significantly reduce amount acquired signal still...

Scanning Transmission Electron Microscopy (STEM) offers high-resolution images that are used to quantify the nanoscale atomic structure and composition of materials biological specimens. In many cases, however, resolution is limited by electron beam damage, since in traditional STEM, a focused scans every location sample raster fashion. this paper, we propose scanning method based on theory Compressive Sensing (CS) subsampling probe locations using line hop sampling scheme significantly...

The realisation of sensing modalities based on the principles compressed is often hindered by discrepancies between mathematical model its operator, which necessary during signal recovery, and actual physical implementation, can amply differ from assumed model. In this paper we tackle bilinear inverse problem recovering a sparse input some unknown, unstructured multiplicative factors affecting sensors that capture each compressive measurement. Our methodology relies collecting few snapshots...

Cryo Focused Ion-Beam Scanning Electron Microscopy (cryo FIB-SEM) enables three-dimensional and nanoscale imaging of biological specimens via a slice view mechanism. The FIB-SEM experiments are, however, limited by slow (typically, several hours) acquisition process the high electron doses imposed on beam sensitive specimen can cause damage. In this work, we present compressive sensing variant cryo capable reducing operational dose increasing speed. We propose two Targeted Sampling (TS)...

Journal Article Exploring Low-dose and Fast Electron Ptychography using l0 Regularisation of Extended Ptychographical Iterative Engine Get access Amirafshar Moshtaghpour, Moshtaghpour Correlated Imaging, Rosalind Franklin Institute, Harwell Science & Innovation Campus, Didcot, UKMechanical, Materials, Aerospace Engineering, University Liverpool, UK Corresponding author: amirafshar.moshtaghpour@rfi.ac.uk. Search for other works by this author on: Oxford Academic Google Scholar Abner...

Abstract Four-dimensional scanning transmission electron microscopy (4-D STEM) is a state-of-the-art image acquisition mode used to reveal high and low mass elements at atomic resolution. The of the momenta each real space probe location allows for various analyses be performed from single dataset, including virtual imaging, electric field analysis, as well analytical or iterative extraction object induced phase shift. However, limiting factor in 4-D STEM speed which bottlenecked by read-out...

Fourier transform interferometry (FTI) is an appealing hyperspectral (HS) imaging modality for many applications demanding high spectral resolution, e.g., in fluorescence microscopy. However, the effective resolution of FTI limited by durability biological elements when exposed to illuminating light. Overexposed are indeed subject photo-bleaching and become unable fluoresce. In this context, acquisition HS volumes based on sampling optical path difference axis at Nyquist rate leads...

Journal Article Compressed STEM Simulations Get access A W Robinson, Robinson Mechanical, Materials, & Aerospace Engineering, University of Liverpool, U.K Corresponding author: A.W.Robinson@liverpool.ac.uk Search for other works by this author on: Oxford Academic Google Scholar D Nicholls, Nicholls J Wells, Wells Distributed Algorithms CDT, Moshtaghpour, Moshtaghpour U.KRosalind Franklin Institute, Harwell Science Innovation Campus, Didcot, U. K I Kirkland, Kirkland Rosalind KDepartment...

Single Pixel (SP) imaging is now a reality in many applications, e.g., biomedical ultrathin endoscope and fluorescent spectroscopy. In this context, schemes exist to improve the light throughput of these device, using structured illumination driven by compressive sensing theory. work, we consider combination SP with Fourier Transform Interferometry (SP-FTI) reach high-resolution HyperSpectral (HS) imaging, as desirable, While association not new, here focus on optimizing spatial...