Explanipedia

Depth from Coupled Optical Differentiation Open

Junjie Luo, Yuxuan Liu, E. Alexander, Qi Guo · 2025

We propose depth from coupled optical differentiation, a low-computation passive-lighting 3D sensing mechanism. It is based on our discovery that per-pixel object distance can be rigorously determined by a coupled pair of optical derivativ…

Bio-Inspired Computational Imaging: Components, Algorithms, and Systems Open

Yi-Chun Hung, Qi Guo, E. Alexander · 2025

Artificial vision has advanced significantly on the basis of insights from human and animal vision. Still, biological vision retains advantages over mainstream computer vision, notably in terms of robustness, adaptability, power consumptio…

Focal Split: Untethered Snapshot Depth from Differential Defocus Open

Junjie Luo, John Mamish, Alan M.N. Fu, Thomas Concannon, Josiah Hester , et al. · 2025

We introduce Focal Split, a handheld, snapshot depth camera with fully onboard power and computing based on depth-from-differential-defocus (DfDD). Focal Split is passive, avoiding power consumption of light sources. Its achromatic optical…

Spectrum from Defocus: Fast Spectral Imaging with Chromatic Focal Stack Open

M. Kerem Aydin, Yi-Chun Hung, Jaclyn Pytlarz, Qi Guo, E. Alexander · 2025

Hyperspectral cameras face harsh trade-offs between spatial, spectral, and temporal resolution in an inherently low-photon regime. Computational imaging systems break through these trade-offs with compressive sensing, but require complex o…

Seeing Eye to AI? Applying Deep-Feature-Based Similarity Metrics to Information Visualization Open

Sheng Long, Angelos Chatzimparmpas, E. Alexander, Matthew Kay, Jessica Hullman · 2025

Judging the similarity of visualizations is crucial to various applications, such as visualization-based search and visualization recommendation systems. Recent studies show deep-feature-based similarity metrics correlate well with percept…

The Evolutionary Map of the Universe: A new radio atlas for the southern hemisphere sky Open

Andrew Hopkins, A. D. Kapińska, J. Marvil, Tessa Vernstrom, J. D. Collier , et al. · 2025

We present the Evolutionary Map of the Universe (EMU) survey conducted with the Australian Square Kilometre Array Pathfinder (ASKAP). EMU aims to deliver the touchstone radio atlas of the southern hemisphere. We introduce EMU and review it…

The Polarisation Sky Survey of the Universe’s Magnetism (POSSUM): Science goals and survey description Open

B. M. Gaensler, G. Heald, N. M. McClure‐Griffiths, C. S. Anderson, Cameron L. Van Eck , et al. · 2025

The Australian SKA Pathfinder (ASKAP) offers powerful new capabilities for studying the polarised and magnetised Universe at radio wavelengths. In this paper, we introduce the Polarisation Sky Survey of the Universe’s Magnetism (POSSUM), a…

Pseudo-3D visualization of Faraday structure in polarized radio sources: methods, science use cases, and development priorities Open

L. Rudnick, C. S. Anderson, W. D. Cotton, Alice Pasetto, E. Alexander , et al. · 2024

We introduce the construction of polarized intensity cubes $\mathbb{P}$(RA, Dec, $\Phi$) and their visualization as movies, as a powerful technique for interpreting Faraday structure. $\mathbb{P}$ is constructed from maps of peak polarized…

Pseudo-3D visualization of Faraday structure in polarized radio sources: methods, science use cases, and development priorities Open

L. Rudnick, C. S. Anderson, W. D. Cotton, Alice Pasetto, E. Alexander , et al. · 2024

We introduce the construction of polarized intensity cubes $P$(RA, Dec, $Φ$) and their visualization as movies, as a powerful technique for interpreting Faraday structure. $P$ is constructed from maps of peak polarized intensity P(RA, Dec)…

Machine learning based stellar classification with highly sparse photometry data Open

Sean Cody, Sebastian Scher, Iain McDonald, A. A. Zijlstra, E. Alexander , et al. · 2024

Background Identifying stars belonging to different classes is vital in order to build up statistical samples of different phases and pathways of stellar evolution. In the era of surveys covering billions of stars, an automated method of i…

Machine learning based stellar classification with highly sparse photometry data Open

Sean Cody, Sebastian Scher, Iain McDonald, A. A. Zijlstra, E. Alexander , et al. · 2024

Background Identifying stars belonging to different classes is vital in order to build up statistical samples of different phases and pathways of stellar evolution. In the era of surveys covering billions of stars, an automated method of i…

HyperColorization: propagating spatially sparse noisy spectral clues for reconstructing hyperspectral images Open

M. Kerem Aydin, Qi Guo, E. Alexander · 2024

Hyperspectral cameras face challenging spatial-spectral resolution trade-offs and are more affected by shot noise than RGB photos taken over the same total exposure time. Here, we present a colorization algorithm to reconstruct hyperspectr…

<span>PySSED</span>: an automated method of collating and fitting stellar spectral energy distributions Open

Iain McDonald, A. A. Zijlstra, N. L. J. Cox, E. Alexander, Alexander Csukai , et al. · 2024

Stellar atmosphere modelling predicts the luminosity and temperature of a star, together with parameters such as the effective gravity and the metallicity, by reproducing the observed spectral energy distribution. Most observational data c…

Radio galaxy zoo EMU: towards a semantic radio galaxy morphology taxonomy Open

Micah Bowles, Hongming Tang, E. Vardoulaki, E. Alexander, Yan Luo , et al. · 2023

We present a novel natural language processing (NLP) approach to deriving plain English descriptors for science cases otherwise restricted by obfuscating technical terminology. We address the limitations of common radio galaxy morphology c…

Thermal Spread Functions (TSF): Physics-guided Material Classification Open

Aniket Dashpute, Vishwanath Saragadam, E. Alexander, Florian Willomitzer, Aggelos K. Katsaggelos , et al. · 2023

Robust and non-destructive material classification is a challenging but crucial first-step in numerous vision applications. We propose a physics-guided material classification framework that relies on thermal properties of the object. Our …

Hydrologic (discharge, level, pressure, voltage, electrical conductivity, and temperature) and atmospheric (pressure and temperature) data from injection experiments and a rain event at Bear Spring, MN, USA – June 10-12, 2016 Open

Andrew J. Luhmann, S. L. Bilek, M. D. Covington, Ronni Grapenthin, Han Woo , et al. · 2023

Galaxy image deconvolution for weak gravitational lensing with unrolled plug-and-play ADMM Open

Tianao Li, E. Alexander · 2023

Removing optical and atmospheric blur from galaxy images significantly improves galaxy shape measurements for weak gravitational lensing and galaxy evolution studies. This ill-posed linear inverse problem is usually solved with deconvoluti…

Identifying anomalous radio sources in the Evolutionary Map of the Universe Pilot Survey using a complexity-based approach Open

Gary Segal, David Parkinson, R. P. Norris, Andrew Hopkins, H. Andernach , et al. · 2023

The Evolutionary Map of the Universe (EMU) large-area radio continuum survey will detect tens of millions of radio galaxies, giving an opportunity for the detection of previously unknown classes of objects. To maximize the scientific value…

Hydra II: Characterisation of Aegean, Caesar, ProFound, PyBDSF, and Selavy source finders Open

M. M. Boyce, Andrew Hopkins, S. Riggi, L. Rudnick, M. Ramsay , et al. · 2023

We present a comparison between the performance of a selection of source finders (SFs) using a new software tool called Hydra. The companion paper, Paper I, introduced the Hydra tool and demonstrated its performance using simulated data. H…

Hydra I: An extensible multi-source-finder comparison and cataloguing tool Open

M. M. Boyce, Andrew Hopkins, S. Riggi, L. Rudnick, M. Ramsay , et al. · 2023

The latest generation of radio surveys are now producing sky survey images containing many millions of radio sources. In this context it is highly desirable to understand the performance of radio image source finder (SF) software and to id…

CS-ROMER: a novel compressed sensing framework for Faraday depth reconstruction Open

Miguel Cárcamo, Anna M. M. Scaife, E. Alexander, J. P. Leahy · 2022

The reconstruction of Faraday depth structure from incomplete spectral polarization radio measurements using the RM Synthesis technique is an under-constrained problem requiring additional regularisation. In this paper we present cs-romer:…

Galaxy Image Deconvolution for Weak Gravitational Lensing with Unrolled Plug-and-Play ADMM Open

Tianao Li, E. Alexander · 2022

Removing optical and atmospheric blur from galaxy images significantly improves galaxy shape measurements for weak gravitational lensing and galaxy evolution studies. This ill-posed linear inverse problem is usually solved with deconvoluti…

Video Data: Optic flow in the natural habitats of zebrafish supports spatial biases in visual self-motion estimation Open

E. Alexander, Lanya T. Cai, Sabrina Fuchs, Tim C. Hladnik, Yue Zhang , et al. · 2022

Video dataset accompanying "Spatial Biases in Optic-Flow Sampling for Self-Motion Estimation in Natural Environments." See accompanying Github repository for more documentation and analysis code.

Video Data: Optic flow in the natural habitats of zebrafish supports spatial biases in visual self-motion estimation Open

E. Alexander, Lanya T. Cai, Sabrina Fuchs, Tim C. Hladnik, Yue Zhang , et al. · 2022

Video dataset accompanying "Spatial Biases in Optic-Flow Sampling for Self-Motion Estimation in Natural Environments." See accompanying Github repository for more documentation and analysis code.

Organizers Open

Ioannis Gkioulekas, Katie Bouman, Caltech Tian, William T. Freeman, Vivek Boominathan , et al. · 2022

Compact single-shot metalens depth sensors inspired by eyes of jumping spiders Open

Qi Guo, Zhujun Shi, Yao‐Wei Huang, E. Alexander, Cheng‐Wei Qiu , et al. · 2019

Significance Nature provides diverse solutions to passive visual depth sensing. Evolution has produced vision systems that are highly specialized and efficient, delivering depth-perception capabilities that often surpass those of existing …

The ASKAP EMU Early Science Project: radio continuum survey of the Small Magellanic Cloud Open

T. Joseph, M. D. Filipović, E. J. Crawford, Ivan S. Bojičić, E. Alexander , et al. · 2019

We present two new radio continuum images from the Australian Square Kilometre Array Pathfinder (ASKAP) survey in the direction of the Small Magellanic Cloud (SMC). These images are part of the Evolutionary Map of the Universe (EMU) Early …

Spectroscopy with the Engineering Development Array: cold H+ at 63 MHz towards the Galactic Centre Open

J. B. R. Oonk, E. Alexander, J. W. Broderick, M. Sokołowski, R. B. Wayth · 2019

The Engineering Development Array (EDA) is a single test station for Square Kilometre Array (SKA) precursor technology. We have used the EDA to detect low-frequency radio recombination lines (RRLs) from the Galactic Centre region. Low-freq…

A Theory of Depth From Differential Defocus Open

E. Alexander · 2019

This document describes a class of computationally-efficient visual depth sensors. Inspired by the visual system of the jumping spider, these sensors are thin lens cameras that observe small changes in optical defocus. Differential defocus…

Primordial 'planetary' rarw gas in a mantle derived amphibole Open

Asish R. Basu, Kazuo Saito, E. Alexander · 2019

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