Roberto Javier López-Sastre

Associate Professor, University of Alcalá 

Office S-342, Polytechnic School
University of Alcalá
Campus Universitario, A2 Km 33.600
28805, Alcalá de Henares (SPAIN)
Tlf: (+34) 91 885 6720
Fax: (+34) 91 885 6699

Teaching 2023-2024:


I received a Master of Electrical Engineering from the University of Alcalá, Spain in 2005. I work at GRAM research group within the Department of Signal Theory and Communications, where I defended my PhD in Electrical Engineering on may 18, 2010, entitled "Visual Vocabularies for Category-Level Object Recognition". In 2008, I spent 6 months in lovely Leuven, working with Tinne Tuytelaars and the VISICS-PSI research group. Summer 2010, I visited Silvio Savarese's group at University of Michigan.

Research interests

In reverse chronological order: offline-RL, meta-learning, semantic visual navigation, AI applied to astrophysics, unsupervised learning, activity recognition, object category pose estimation, semantic visual vocabularies, category-level object recognition, traffic signs recognition/detection.


PhD Students:

Postdocs: Visitors:
  • Sergio Hernández-García (2022, PhD student from King Juan Carlos University)
  • Nadjia Khatir (2017, PhD student from University of Oran)
Master's and Undergraduate Students:
  • Pablo Ríos-Navarro (Master student)
  • Rafael Flor-Rodríguez (Master student)
  • Eduardo Blanco-Fernández (Master student)

Selected Publications


Realistic Continual Learning Approach using Pre-trained Models

N. Nasri, C. Gutiérrez-Álvarez, S. Lafuente-Arroyo, S. Maldonado-Bascón, R. J. López-Sastre.

ArXiv, 2024. PDF

Visual Semantic Navigation with Real Robots

C. Gutiérrez-Álvarez, P. Ríos-Navarro, R. Flor-Rodríguez, F. J. Acevedo-Rodríguez, R. J. López-Sastre.

ArXiv, 2023. PDF Code


Towards Clear Evaluation of Robotic Visual Semantic Navigation

C. Gutiérrez-Álvarez, S. Hernandez-García, N. Nasri, A. Cuesta-Infante, R. J. López-Sastre.

ICARA, 2023. PDF Code


Assistive Robot with an AI-Based Application for the Reinforcement of Activities of Daily Living: Technical Validation with Users Affected by Neurodevelopmental Disorders

N. Nasri, R. J. López-Sastre, S. Pacheco-da-Costa, I. Fernández-Munilla, C. Gutiérrez-Álvarez, T. Pousada-Garcı́a, F. J. Acevedo-Rodríguez, S. Maldonado-Bascón,.

Applied Sciences, 2022. PDF

Stellar mass and radius estimation using artificial intelligence

A. Moya and R. J. López-Sastre.

Astronomy & Astrophysics, 2022. PDF Code


Live Video Action Recognition from Unsupervised Action Proposals

R. J. López-Sastre, M. Baptista-Ríos, F. J. Acevedo-Rodríguez, P. Martín-Martín, S. Maldonado-Bascón.

17th International Conference on Machine Vision Applications (MVA), 2021. PDF

AI for dating stars: a benchmarking study for gyrochronology

A. Moya, J. Recio-Martínez and R. J. López-Sastre.

1st Workshop on AI for Space, CVPR, 2021. PDF Supplementary Code


Rethinking Online Action Detection in Untrimmed Videos: A Novel Online Evaluation Protocol

M. Baptista-Ríos, R. J. López-Sastre, F. Caba Heilbron, Jan van Gemert, F. J. Acevedo-Rodríguez, S. Maldonado-Bascón.

IEEE Access, 2020. PDF Code

Unsupervised Action Proposals Using Support Vector Classifiers for Online Video Processing

M. Baptista-Ríos, R. J. López-Sastre, F. J. Acevedo-Rodríguez, P. Martín-Martín, S. Maldonado-Bascón.

Sensors, 2020. PDF Code

Learning to Learn Face-PAD: a lifelong learning approach

D. Pérez-Cabo, D. Jiménez-Cabello, A. Costa-Pazo, R. J. López-Sastre..

IJCB, 2020. PDF Code


Deep Anomaly Detection for Generalized Face Anti-Spoofing

D. Pérez-Cabo, D. Jiménez-Cabello, A. Costa-Pazo, R. J. López-Sastre.

Chalearn Looking at People series Face Spoofing Attack Workshop and Challenge, CVPR 2019. PDF

Generalized Presentation Attack Detection: a face anti-spoofing evaluation proposal

A. Costa-Pazo, D. Jiménez-Cabello, E. Vázquez-Fernández, J. L. Alba-Castro, R. J. López-Sastre.

International Conference on Biometrics (ICB) 2019. PDF Code

Combining Online Clustering and Rank Pooling Dynamics for Action Proposals

Nadjia Khatir, Roberto J. López-Sastre, Marcos Baptista-Ríos, Safia Nait-Bahloul, Francisco Javier Acevedo-Rodríguez.


Collision anticipation via deep reinforcement learning for visual navigation

E. Gutiérrez-Maestro, R. J. López-Sastre, S. Maldonado-Bascón.


Learning to Exploit the Prior Network Knowledge for Weakly-Supervised Semantic Segmentation

C. Redondo-Cabrera, M. Baptista-Ríos, R. J. López-Sastre.

IEEE Transactions on Image Processing 2019 PDF Code

Answering Visual-Relational Queries in Web-Extracted Knowledge Graphs

D. Oñoro-Rubio, M. Niepert, A. García-Durán, R. González, R. J. López-Sastre.

AKBC 2019 PDF Code

Unsupervised learning from videos using temporal coherency deep networks

C. Redondo-Cabrera and R. J. López-Sastre.

Computer Vision and Image Understanding 2019. PDF Code


The challenge of simultaneous object detection and pose estimation: a comparative study

D. Oñoro-Rubio, R. J. López-Sastre, C. Redondo-Cabrera, P. Gil-Jiménez.

Image and Vision Computing 2018. PDF Code

In pixels we trust: From Pixel Labeling to Object Localization and Scene Categorization

C. Herránz-Perdigureo, C. Redondo-Cabrera and R. J. López-Sastre.

IROS, 2018. PDF Code Video

Learning Short-Cut Connections for Object Counting

D. Oñoro-Rubio, M. Niepert, R. J. López-Sastre.

BMVC, 2018 PDF

ISA^2: Intelligent Speed Adaptation from Appearance

C. Herránz-Perdigureo and R. J. López-Sastre.

IROS 2018 Workshop, 10th Planning, Perception and Navigation for Intelligent Vehicles (PPNIV'18). PDF ISA^2 Dataset


Pose Estimation Errors, the Ultimate Diagnosis

C. Redondo-Cabrera, R. J. López-Sastre, Y. Xiang , T. Tuytelaars, S. Savarese.

ECCV, 2016. PDF Code Supplementary

Towards perspective-free object counting with deep learning

D. Oñoro-Rubio and R. J. López-Sastre.

ECCV, 2016. PDF Code Video

Unsupervised Robust Feature-based Partition Ensembling to Discover Categories

R. J. López-Sastre.

CVPR Workshops, Robust Features for Computer Vision, 2016. PDF Code Video


Because better detections are still possible: Multi-aspect Object Detection with Boosted Hough Forest

C. Redondo-Cabrera, R. J. López-Sastre.

BMVC 2015. PDF Supplementary Code

Extremely Overlapping Vehicle Counting

R. Guerrero-Gómez-Olmedo, B. Torre-Jimenez, R. J. López-Sastre, S. Maldonado-Bascón and Daniel Oñoro-Rubio.

IbPRIA 2015. PDF TRANCOS Dataset

Fast Head Pose Estimation for Human-Computer Interaction

M. García-Montero, C. Redondo-Cabrera, R. López-Sastre and Tinne Tuytelaars.

IbPRIA 2015. PDF Code Video

Structured Output Prediction with Hierarchical Loss Functions for Seafloor Imagery Taxonomic Categorization.

N. Nourani-Vatani, R. López-Sastre and S. Williams.

IbPRIA 2015. PDF Code Video


Recognizing in the Depth: Selective 3D Spatial Pyramid Matching Kernel for Object and Scene Categorization

C. Redondo-Cabrera, R. J. López-Sastre, J. Acevedo-Rodríguez, S. Maldonado-Bascon.

Image and Vision Computing 2014. PDF Project page

All together now: Simultaneous Object Detection and Continuous Pose Estimation using a Hough Forest with Probabilistic Locally Enhanced Voting

C. Redondo-Cabrera, R. J. López-Sastre, T. Tuytelaars.

BMVC 2014. PDF Project page


Evaluating 3D spatial pyramids for classifying 3D shapes

R. J. López-Sastre, A. García-Fuertes, C. Redondo-Cabrera, F. J. Acevedo-Rodríguez, S. Maldonado-Bascón.

Computers & Graphics 2013. PDF Project page - Executable Paper

Vehicle Tracking by Simultaneous Detection and Viewpoint Estimation

R. Guerrero-Gómez-Olmedo, R. J. López-Sastre, S. Maldonado-Bascón, A. Fernández-Caballero.


Heterogeneous Visual Codebook Integration via Consensus Clustering for Visual Categorization

R. J. López-Sastre, J. Renes-Olalla, P. Gil-Jiménez, S. Maldonado-Bascón, S. Lafuente-Arroyo.

IEEE TCSVT 2013. PDF Project page


SURFing the Point Clouds: Selective 3D Spatial Pyramids for Category-level Object Recognition

C. Redondo-Cabrera, R. J. López-Sastre, F.J. Acevedo-Rodríguez, S. Maldonado-Bascón.

IEEE CVPR 2012. PDF Project page


Deformable Part Models Revisited: A Performance Evaluation for Object Category Pose Estimation

R. J. López-Sastre, T. Tuytelaars, S. Savarese.

IEEE ICCV 2011, 1st IEEE Workshop on Challenges and Opportunities in Robot Perception. PDF Project page

Fast Reciprocal Nearest Neighbors Clustering

R. J. López-Sastre, D. Oñoro-RUbio, P. Gil-Jiménez, S. Maldonado-Bascón.

Signal Processing. PDF Code

Towards a more discriminative and semantic visual vocabulary

R. J. López-Sastre, T. Tuytelaars, J. Acevedo-Rodríguez, S. Maldonado-Bascón.

Computer Vision and Image Understanding. PDF Code

Visual Word Aggregation

R. J. López-Sastre, J. Renes-Olalla, P. Gil-Jiménez, S. Maldonado-Bascón.

ibPRIA2011. PDF


Visual Vocabularies for Category-Level Object Recognition

R. J. López-Sastre

Ph.D. Thesis. PDF


Class Representative Visual Words for Category-level Object Recognition

R. J. López-Sastre, T. Tuytelaars and S. Maldonado-Bascón.

ibPRIA2009. PDF


Fundaments in luminance and retroreflectivity measurements of vertical traffic signs using a color digital camera

P. Siegmann, R. J. López-Sastre, P. Gil-Jiménez, S. Lafuente-Arroyo, S. Maldonado-Bascón.

IEEE Transactions on Instrumentation and Measurement. PDF


Computer Algebra Algorithms Applied to Computer Vision in a Parking Management System

R. J. López-Sastre, P. Gil-Jiménez, F.J. Acevedo, S. Maldonado.


Road-sign Detection and recognition based on support vector machines

S. Maldonado-Bascón, S. Lafuente-Arroyo, P. Gil-Jiménez, H. Gómez-Moreno and F. López-Ferreras.

IEEE trans. on Intelligent transportation systems. PDF


An Approach to the Recognition of Information Traffic Sign Based on 2-D Homography and SVMs

A. Vázquez-Reina, R. J. López-Sastre, P. Siegmann, S. Lafuente-Arroyo and H. Gómez-Moreno.

Proceedings of Advanced Concepts for Intelligent Vision Systems 2006. PDF

Adaptive Traffic Road Sign Panels Text Extraction

A. Vázquez-Reina, R. J. López-Sastre, S. Lafuente-Arroyo and P. Gil-Jiménez.



Recognition of Mandatory Traffic Signs using the Hausdorff Distance

R. J. López-Sastre, S. Lafuente-Arroyo, P. Siegmann, P. Gil-Jiménez, A. Vázquez-Reina.