← Search

Samuel Pinilla

7 accepted papers

2024

Global Convergence of Alternating Direction Method of Multipliers for Invex Objective Losses

ICASSP 2024accepted

The Alternating Direction Method of Multipliers (ADMM) is uniquely suited for large-scale signal restoration problems, owing to its parallelizability. ADMM has been successfully deployed into several imaging modalities, including blind ptychography, phase retrieval, computer tomography, network unro…

Cited by 0SourceScholar
2024

Global Optimality for Non-linear Constrained Restoration Problems via Invexity

ICLR 2024poster

Signal restoration is an important constrained optimization problem with significant applications in various domains. Although non-convex constrained optimization problems have been shown to perform better than convex counterparts in terms of reconstruction quality, convex constrained optimization p…

Cited by 4SourcePDFScholar
2023

Unique Bispectrum Inversion for Signals with Finite Spectral/Temporal Support

ICASSP 2023accepted

Retrieving a signal from its triple correlation spectrum, also called bispectrum, arises in a wide range of signal processing problems. Conventional methods do not provide an accurate inversion of bispectrum to the underlying signal. In this paper, we present an approach that uniquely recovers signa…

Cited by 1SourceScholar
2022

Improved Imaging by Invex Regularizers with Global Optima Guarantees

NeurIPS 2022accept

Image reconstruction enhanced by regularizers, e.g., to enforce sparsity, low rank or smoothness priors on images, has many successful applications in vision tasks such as computer photography, biomedical and spectral imaging. It has been well accepted that non-convex regularizers normally perform b…

Cited by 10SourcePDFScholar
2021

Banraw: Band-Limited Radar Waveform Design Via Phase Retrieval

ICASSP 2021accepted

This paper presents a uniqueness result which states that a band- limited signal can be recovered from at least 3B measurements where B is the bandwidth from the radar ambiguity function (AF). This function is a two-dimensional mapping of the propagation delay and Doppler frequency. This formal mode…

Cited by 9SourceScholar
2018

Phase Retrieval via Smoothing Projected Gradient Method

ICASSP 2018accepted

Phase retrieval is a kind of ill-posed inverse problem, which is present in various applications, such as optics, astronomical imaging, and X-ray crystallography. Mathematically this inverse problem consists on recovering an unknown signal x ∈ R <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xm…

Cited by 0SourceScholar
2017

Stochastic Truncated Wirtinger Flow Algorithm for phase retrieval using boolean coded apertures

ICASSP 2017accepted

X-ray crystallography is an experimental technique to estimate the 3D atomic positions of the elements present in a crystal. This technique constructs the 3D structure from the phase of diffracted and patterned X-rays (DPX). Multiple intensity DPX measurements are acquired to solve the phase retriev…

Cited by 0SourceScholar