Search Results for author: Alejandro C. Frery

Found 17 papers, 0 papers with code

Comparing Samples from the $\mathcal{G}^0$ Distribution using a Geodesic Distance

no code implementations23 Apr 2019 Alejandro C. Frery, Juliana Gambini

The $\mathcal{G}^0$ distribution is widely used for monopolarized SAR image modeling because it can characterize regions with different degree of texture accurately.

Parameter Estimation for the Single-Look $\mathcal{G}^0$ Distribution

no code implementations29 Sep 2018 Débora Chan, Andrea Rey, Juliana Gambini, Alejandro C. Frery

It is well-known that these images are affected by speckle, and prone to contamination as double bounce and corner reflectors.

Unsupervised Classification of PolSAR Data Using a Scattering Similarity Measure Derived from a Geodesic Distance

no code implementations1 Dec 2017 Debanshu Ratha, Avik Bhattacharya, Alejandro C. Frery

This geodesic distance is obtained between an elementary target and the observed Kennaugh matrix, and it is further utilized to compute a similarity measure between scattering mechanisms.

General Classification

Unassisted Quantitative Evaluation Of Despeckling Filters

no code implementations19 Apr 2017 Luis Gomez, Raydonal Ospina, Alejandro C. Frery

We, then, assess the quality of a filter by the closeness of $I$ to the hypothesis that it is adherent to the statistical properties of pure speckle.

The Geodesic Distance between $\mathcal{G}_I^0$ Models and its Application to Region Discrimination

no code implementations1 Jan 2017 José Naranjo-Torres, Juliana Gambini, Alejandro C. Frery

This paper presents a new proposal for feature extraction and region discrimination in SAR imagery, using the geodesic distance as a measure of dissimilarity between $\mathcal{G}_I^0$ models.

Classification and Verification of Online Handwritten Signatures with Time Causal Information Theory Quantifiers

no code implementations26 Jan 2016 Osvaldo A. Rosso, Raydonal Ospina, Alejandro C. Frery

We present a new approach for online handwritten signature classification and verification based on descriptors stemming from Information Theory.

General Classification

Optical images-based edge detection in Synthetic Aperture Radar images

no code implementations24 Aug 2015 Gilberto P. Silva Junior, Alejandro C. Frery, Sandra Sandri, Humberto Bustince, Edurne Barrenechea, Cédric Marco-Detchart

We compare the modified and unmodified versions of the gravitational edge detection technique with the well-established one proposed by Canny, as well as with a recent multiscale fuzzy-based technique proposed by Lopez-Molina et Alejandro We also address the issues of aggregation of gray level images before and after edge detection and of filtering.

Edge Detection

Classification of Complex Wishart Matrices with a Diffusion-Reaction System guided by Stochastic Distances

no code implementations17 Jul 2015 Luis Gomez, Luis Alvarez, Luis Mazorra, Alejandro C. Frery

We propose a new method for PolSAR (Polarimetric Synthetic Aperture Radar) imagery classification based on stochastic distances in the space of random matrices obeying complex Wishart distributions.

General Classification

Bias Correction and Modified Profile Likelihood under the Wishart Complex Distribution

no code implementations18 Apr 2014 Abraão D. C. Nascimento, Alejandro C. Frery, Renato J. Cintra

This paper proposes improved methods for the maximum likelihood (ML) estimation of the equivalent number of looks $L$.

A New Algorithm of Speckle Filtering using Stochastic Distances

no code implementations29 Aug 2013 Leonardo Torres, Tamer Cavalcante, Alejandro C. Frery

The proposal is compared with the Lee's filter using a protocol based on Monte Carlo.

SAR Image Despeckling Algorithms using Stochastic Distances and Nonlocal Means

no code implementations20 Aug 2013 Leonardo Torres, Alejandro C. Frery

The proposals are compared with the Improved Sigma filter and with anisotropic diffusion for speckled data (SRAD) using a protocol based on Monte Carlo simulation.

Sar Image Despeckling

Speckle Reduction with Adaptive Stack Filters

no code implementations8 Jun 2013 María Elena Buemi, Alejandro C. Frery, Heitor S. Ramos

We study the performance of adaptive stack filters when they are applied to speckled imagery, in particular to Synthetic Aperture Radar (SAR) images.

General Classification

Analytic Expressions for Stochastic Distances Between Relaxed Complex Wishart Distributions

no code implementations19 Apr 2013 Alejandro C. Frery, Abraão D. C. Nascimento, Renato J. Cintra

The scaled complex Wishart distribution is a widely used model for multilook full polarimetric SAR data whose adequacy has been attested in the literature.

Cannot find the paper you are looking for? You can Submit a new open access paper.