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Related papers: Photo-$z$ Estimation with Normalizing Flow

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A new approach to estimating photometric redshifts - using Artificial Neural Networks (ANNs) - is investigated. Unlike the standard template-fitting photometric redshift technique, a large spectroscopically-identified training set is…

Astrophysics · Physics 2009-11-07 Andrew E. Firth , Ofer Lahav , Rachel S. Somerville

Building on the first paper in this series (Duncan et al. 2018), we present a study investigating the performance of Gaussian process photometric redshift (photo-z) estimates for galaxies and active galactic nuclei detected in deep radio…

Astrophysics of Galaxies · Physics 2018-05-24 Kenneth J Duncan , Matt J. Jarvis , Michael J. I. Brown , Huub J. A. Rottgering

Normalizing Flows (NFs) learn invertible mappings between the data and a Gaussian distribution. Prior works usually suffer from two limitations. First, they add random noise to training samples or VAE latents as data augmentation,…

Computer Vision and Pattern Recognition · Computer Science 2025-12-04 Qinyu Zhao , Guangting Zheng , Tao Yang , Rui Zhu , Xingjian Leng , Stephen Gould , Liang Zheng

Optical microscopy is an essential tool in biology and medicine. Imaging thin, yet non-flat objects in a single shot (without relying on more sophisticated sectioning setups) remains challenging as the shallow depth of field that comes with…

Image and Video Processing · Electrical Eng. & Systems 2020-10-14 Adrian Shajkofci , Michael Liebling

Normalizing Flows (NFs) are universal density estimators based on Neural Networks. However, this universality is limited: the density's support needs to be diffeomorphic to a Euclidean space. In this paper, we propose a novel method to…

Machine Learning · Computer Science 2022-02-02 Christian Horvat , Jean-Pascal Pfister

Normalizing Flows (NFs) are flexible explicit generative models that have been shown to accurately model complex real-world data distributions. However, their invertibility constraint imposes limitations on data distributions that reside on…

Computer Vision and Pattern Recognition · Computer Science 2022-08-19 Janis Postels , Martin Danelljan , Luc Van Gool , Federico Tombari

Uncertainty quantification provides quantitative measures on the reliability of candidate solutions of ill-posed inverse problems. Due to their sequential nature, Monte Carlo sampling methods require large numbers of sampling steps for…

Geophysics · Physics 2021-04-14 Ali Siahkoohi , Felix J. Herrmann

Noise modeling and reduction are fundamental tasks in low-level computer vision. They are particularly important for smartphone cameras relying on small sensors that exhibit visually noticeable noise. There has recently been renewed…

Computer Vision and Pattern Recognition · Computer Science 2022-06-03 Shayan Kousha , Ali Maleky , Michael S. Brown , Marcus A. Brubaker

Photometric wide-field surveys are imaging the sky in unprecedented detail. These surveys face a significant challenge in efficiently estimating galactic photometric redshifts while accurately quantifying associated uncertainties. In this…

The importance of photometric galaxy redshift estimation is rapidly increasing with the development of specialised powerful observational facilities. We develop a new photometric redshift estimation workflow TOPz to provide reliable and…

Machine learning photo-z methods, trained directly on spectroscopic redshifts, provide a viable alternative to traditional template fitting methods but may not generalise well on new data that deviates from that in the training set. In this…

Instrumentation and Methods for Astrophysics · Physics 2024-02-02 Shingo Tanigawa , Karl Glazebrook , Colin Jacobs , Ivo Labbe , Alex K. Qin

Diffusion models have shown great promise for image and video generation, but sampling from state-of-the-art models requires expensive numerical integration of a generative ODE. One approach for tackling this problem is rectified flows,…

Computer Vision and Pattern Recognition · Computer Science 2024-10-10 Sangyun Lee , Zinan Lin , Giulia Fanti

Despite the high accuracy of photometric redshifts (zphot) derived using Machine Learning (ML) methods, the quantification of errors through reliable and accurate Probability Density Functions (PDFs) is still an open problem. First, because…

Supernova (SN) classification and redshift estimation using photometric data only have become very important for the Large Synoptic Survey Telescope (LSST), given the large number of SNe that LSST will observe and the impossibility of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-02 Mi Dai , Steve Kuhlmann , Yun Wang , Eve Kovacs

Photometric galaxy surveys are an essential tool to further our understanding of the large-scale structure of the universe, its matter and energy content and its evolution. These surveys necessitate the determination of the galaxy redshifts…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-06 Pol Martí , Ramon Miquel , Anne Bauer , Enrique Gaztañaga

Normalizing flows define a probability distribution by an explicit invertible transformation $\boldsymbol{\mathbf{z}}=f(\boldsymbol{\mathbf{x}})$. In this work, we present implicit normalizing flows (ImpFlows), which generalize normalizing…

Machine Learning · Statistics 2021-03-18 Cheng Lu , Jianfei Chen , Chongxuan Li , Qiuhao Wang , Jun Zhu

Estimating the expectation of a real-valued function of a random variable from sample data is a critical aspect of statistical analysis, with far-reaching implications in various applications. Current methodologies typically assume…

Machine Learning · Computer Science 2026-02-18 Paweł Lorek , Rafał Nowak , Rafał Topolnicki , Tomasz Trzciński , Maciej Zięba , Aleksandra Krystecka

We present deep near-infrared (NIR) medium-bandwidth photometry over the wavelength range 1-1.8 microns in the All-wavelength Extended Groth strip International Survey (AEGIS) and Cosmic Evolution Survey (COSMOS) fields. The observations…

We present a comprehensive comparative study of three generative modeling paradigms: Denoising Diffusion Probabilistic Models (DDPM), Conditional Flow Matching (CFM), and MeanFlow. While DDPM and CFM require iterative sampling, MeanFlow…

Computer Vision and Pattern Recognition · Computer Science 2025-11-27 Umang Agarwal , Rudraksh Sangore , Sumit Laddha