Search Results for author: Luiz G. Hafemann

Found 12 papers, 8 papers with code

Detecting and Matching Related Objects with One Proposal Multiple Predictions

1 code implementation23 Apr 2021 Yang Liu, Luiz G. Hafemann, Michael Jamieson, Mehrsan Javan

Tracking players in sports videos is commonly done in a tracking-by-detection framework, first detecting players in each frame, and then performing association over time.

Meta-learning for fast classifier adaptation to new users of Signature Verification systems

1 code implementation17 Oct 2019 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

This is particularly challenging for skilled forgeries, where a forger practices imitating the user's signature, and often is able to create forgeries visually close to the original signatures.

Meta-Learning

Universal Adversarial Audio Perturbations

1 code implementation arXiv preprint 2019 Sajjad Abdoli, Luiz G. Hafemann, Jerome Rony, Ismail Ben Ayed, Patrick Cardinal, Alessandro L. Koerich

We demonstrate the existence of universal adversarial perturbations, which can fool a family of audio classification architectures, for both targeted and untargeted attack scenarios.

Audio Classification

Characterizing and evaluating adversarial examples for Offline Handwritten Signature Verification

2 code implementations10 Jan 2019 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

The phenomenon of Adversarial Examples is attracting increasing interest from the Machine Learning community, due to its significant impact to the security of Machine Learning systems.

BIG-bench Machine Learning Object Recognition

Decoupling Direction and Norm for Efficient Gradient-Based L2 Adversarial Attacks and Defenses

5 code implementations23 Nov 2018 Jérôme Rony, Luiz G. Hafemann, Luiz S. Oliveira, Ismail Ben Ayed, Robert Sabourin, Eric Granger

Research on adversarial examples in computer vision tasks has shown that small, often imperceptible changes to an image can induce misclassification, which has security implications for a wide range of image processing systems.

Fixed-sized representation learning from Offline Handwritten Signatures of different sizes

1 code implementation2 Apr 2018 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

Methods for learning feature representations for Offline Handwritten Signature Verification have been successfully proposed in recent literature, using Deep Convolutional Neural Networks to learn representations from signature pixels.

Representation Learning

DESlib: A Dynamic ensemble selection library in Python

2 code implementations14 Feb 2018 Rafael M. O. Cruz, Luiz G. Hafemann, Robert Sabourin, George D. C. Cavalcanti

DESlib is an open-source python library providing the implementation of several dynamic selection techniques.

Learning Features for Offline Handwritten Signature Verification using Deep Convolutional Neural Networks

4 code implementations16 May 2017 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

Verifying the identity of a person using handwritten signatures is challenging in the presence of skilled forgeries, where a forger has access to a person's signature and deliberately attempt to imitate it.

Analyzing features learned for Offline Signature Verification using Deep CNNs

no code implementations15 Jul 2016 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

Research on Offline Handwritten Signature Verification explored a large variety of handcrafted feature extractors, ranging from graphology, texture descriptors to interest points.

Writer-independent Feature Learning for Offline Signature Verification using Deep Convolutional Neural Networks

no code implementations4 Apr 2016 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

Automatic Offline Handwritten Signature Verification has been researched over the last few decades from several perspectives, using insights from graphology, computer vision, signal processing, among others.

Offline Handwritten Signature Verification - Literature Review

no code implementations28 Jul 2015 Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

The area of Handwritten Signature Verification has been broadly researched in the last decades, but remains an open research problem.

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