activity
20152026
most citedLearning Features for Offline Handwritten Signature Verification using Deep Convolutional Neural Networks

387 citations · 1.1k across the 17 of their papers we have counts for

collaborators

19 papers

cs.CV2026

FaceSnap: Real-Time Personalized Lightstage Facial Performance Capture

Rukhshanda Hussain, Noé Artru, Emeline Got +6

Lightstage facial capture produces production-quality digital humans, but it is resource and labor-intensive. Multi-camera setups, hours of computation, and massive data storage cr…

cs.CV2026

KM-Speaker: Keypoint-Based Style Control for High-Quality Speech-Driven 3D Facial Animation and Dialogue Localization

Arthur Josi, Emeline Got, Abdallah Dib +2

Speech-driven 3D facial animation methods face significant challenges in simultaneously achieving high-fidelity motion and precise artistic control at production quality. Existing…

cs.GR2025

Geometry-Aware Texture Generation for 3D Head Modeling with Artist-driven Control

Amin Fadaeinejad, Abdallah Dib, Luiz Gustavo Hafemann +6

Creating realistic 3D head assets for virtual characters that match a precise artistic vision remains labor-intensive. We present a novel framework that streamlines this process by…

cs.GR2025★ 1 cited

Model See Model Do: Speech-Driven Facial Animation with Style Control

Yifang Pan, Karan Singh, Luiz Gustavo Hafemann

Speech-driven 3D facial animation plays a key role in applications such as virtual avatars, gaming, and digital content creation. While existing methods have made significant progr…

cs.CV2024

SEREP: Semantic Facial Expression Representation for Robust In-the-Wild Capture and Retargeting

Arthur Josi, Luiz Gustavo Hafemann, Abdallah Dib +3

Monocular facial performance capture in-the-wild is challenging due to varied capture conditions, face shapes, and expressions. Most current methods rely on linear 3D Morphable Mod…

cs.CV2023

MoSAR: Monocular Semi-Supervised Model for Avatar Reconstruction using Differentiable Shading

Abdallah Dib, Luiz Gustavo Hafemann, Emeline Got +4

Reconstructing an avatar from a portrait image has many applications in multimedia, but remains a challenging research problem. Extracting reflectance maps and geometry from one im…

cs.CV2023

A Scale-Invariant Trajectory Simplification Method for Efficient Data Collection in Videos

Yang Liu, Luiz Gustavo Hafemann

Training data is a critical requirement for machine learning tasks, and labeled training data can be expensive to acquire, often requiring manual or semi-automated data collection…

cs.CV2021★ 1 cited

Detecting and Matching Related Objects with One Proposal Multiple Predictions

Yang Liu, Luiz G. Hafemann, Michael Jamieson +1

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. While for…

cs.CV2020

Group Activity Detection from Trajectory and Video Data in Soccer

Ryan Sanford, Siavash Gorji, Luiz G. Hafemann +2

Group activity detection in soccer can be done by using either video data or player and ball trajectory data. In current soccer activity datasets, activities are labelled as atomic…

cs.CV2019

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

Luiz G. Hafemann, Robert Sabourin, Luiz S. Oliveira

Offline Handwritten Signature verification presents a challenging Pattern Recognition problem, where only knowledge of the positive class is available for training. While classifie…

cs.LG2019★ 35 cited

Universal Adversarial Audio Perturbations

Sajjad Abdoli, Luiz G. Hafemann, Jerome Rony +3

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

cs.CV2019★ 58 cited

Characterizing and evaluating adversarial examples for Offline Handwritten Signature Verification

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 syst…

cs.CV2018★ 1 cited

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

Jérôme Rony, Luiz G. Hafemann, Luiz S. Oliveira +3

Research on adversarial examples in computer vision tasks has shown that small, often imperceptible changes to an image can induce misclassification, which has security implication…

cs.CV2018★ 67 cited

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

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 Ne…

cs.LG2018★ 75 cited

DESlib: A Dynamic ensemble selection library in Python

Rafael M. O. Cruz, Luiz G. Hafemann, Robert Sabourin +1

DESlib is an open-source python library providing the implementation of several dynamic selection techniques. The library is divided into three modules: (i) \emph{dcs}, containing…

cs.CV2017★ 387 cited

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

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 deliberat…

cs.CV2016★ 64 cited

Analyzing features learned for Offline Signature Verification using Deep CNNs

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.…

cs.CV2016★ 148 cited

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

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, signa…

cs.CV2015★ 231 cited

Offline Handwritten Signature Verification - Literature Review

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. The objective of signature verification system…