A Photograph showing a dog.

I'm Lucas, a PhD student in Computer Vision/Machine Learning at University of Campinas. My research interests are Explainability and Weakly Supervised Semantic Segmentation problems.

"All we have to decide is what to do with the time that is given us."

Blog Posts

Aug 30, 2021

Activation, Cross-Entropy and Logits

Discussion around the activation loss functions commonly used in Machine Learning problems, considering their multiple forms.

Aug 30, 2021

Santos Dumont Super Computer

Accessing and using the SDumont infrastructure for Deep Learning research.

Jul 16, 2021

Segmentation and Detection

A comparison between edge-based segmentation, Felzenszwalb's method and morphological segmentation.

Jun 11, 2021

K-Means and Hierarchical Clustering

Efficient clustering algorithms implementations in TensorFlow and NumPy.

Jun 9, 2021

The 2D Fourier Transform

Applying the Fourier Transform over images using TensorFlow.

Jun 8, 2021

A Vectorized Implementation of The Convolution Operation

Implementing a few numeric operations over images using Python programming language.

Mar 23, 2021

Class Activation Mapping

Explaining AI with Grad-CAM.

Jan 15, 2021

Explaining Machine Learning Models

Explainability using tree decision visualization, weight composition, and gradient-based saliency maps.

see all posts

Publications

  1. L. David, H. Pedrini, Z. Dias, and A. Rocha, “Connoisseur: provenance analysis in paintings,” in 2021 IEEE Symposium Series on Computational Intelligence (SSCI), 2021, pp. 1–8.
  2. L. O. David, H. Pedrini, Z. Dias, and A. Rocha, “Authentication of Vincent van Gogh’s work,” in International Conference on Computer Analysis of Images and Patterns, 2021, pp. 371–380.
  3. L. O. David, “A Study of the ISOMAP Algorithm and Its Applications in Machine Learning,” 2015.
  4. L. David, H. Pedrini, and Z. Dias, “MinMax-CAM: Improving Focus of CAM-based Visualization Techniques in Multi-label Problems,” in 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, 2022, vol. 4, pp. 106–117.
  5. L. David, “Segmentation and Detection of Simple Geometric Shapes.”
  6. G. B. de Oliveira et al., “Bias Assessment in Medical Imaging Analysis: A Case Study on Retinal OCT Image Classification.,” in ICAART (3), 2022, pp. 574–580.
  7. L. David, H. Pedrini, and Z. Dias, “P-NOC: Adversarial CAM Generation for Weakly Supervised Semantic Segmentation,” arXiv preprint arXiv:2305.12522, 2023.
  8. L. David, H. Pedrini, and Z. Dias, “MinMax-CAM: Increasing Precision of Explaining Maps by Contrasting Gradient Signals and Regularizing Kernel Usage,” in International Joint Conference on Computer Vision, Imaging and Computer Graphics, 2022, pp. 222–247.

see all publications


Projects

wikiart

Full retriever for art and metadata in http://wikiart.org/

221 stars • Last pushed at Sep 18, 2022

keras-explainable

Efficient explaining AI algorithms for Keras models

14 stars • Last pushed at Nov 30, 2022

mazerunner

Final Project for Artificial Intelligence 2016-1 class at UNICAMP.

5 stars • Last pushed at Dec 8, 2017

minmax-cam

Official implementation for the paper "MinMax-CAM: Improving Focus of CAM-Based Visualization Techniques in Multi-Label Problems"

4 stars • Last pushed at Feb 15, 2022

grapher

RESTful APIs creator based on resource schematics.

3 stars • Last pushed at Apr 24, 2020

jmagic

A Java environment in which we (and AI agents) can play the game Magic: The Gathering.

3 stars • Last pushed at Jul 27, 2021

convolutional

Convolutional Nets implemented in pyCuda.

2 stars • Last pushed at Jul 26, 2021

algorithms-in-tensorflow

Experiments with gpu support, persistent logging and stable docker env.

2 stars • Last pushed at Dec 10, 2021

artificial

A basic API for artificial intelligent agents described in the book "Artificial Intelligence: A Modern Approach", by Russell and Norvig.

2 stars • Last pushed at Oct 14, 2021

tsp

Exploring shortest-paths in the Traveling Salesman Problem.

2 stars • Last pushed at Nov 19, 2015

manifold-learning

Final project as student at Universidade Federal de Sao Carlos.

2 stars • Last pushed at Feb 9, 2023

resnet38d-tf

Tensorflow implementation for ResNet38 dilated, with weights

1 stars • Last pushed at May 30, 2022

see all repositories


Reports

MO444 - Final Report: Classificando impacto humano sobre a floresta amazônica a partir de imagens de satélite

Application of multiple strategies involving deep convolutional networks in the solution of the "Planet: Understanding the Amazon from Space" challenge.

Published at Jun 19, 2021 Satellite Imagery Multi-label Convolutional Networks Portuguese

MO443 - Assignment 4: Texture Descriptors

Application of texture-describing methods to extract descriptors of texture samples.

Published at Jun 16, 2021 Computer Vision Texture

MO443 - Assignment 3: Image Segmentation

Segmentation of geometric shapes and blood cells using classic Computer Vision techniques.

Published at Jun 12, 2021 Computer Vision Segmentation

MO443 - Assignment 2: Discrete Fourier Transform

Application of the Discrete Fourier Transform over images using TensorFlow.

Published at May 7, 2021 Computer Vision FFT

MO443 - Assignment 1: Image Manipulation

Implementation of basic operations over images using Python programming language.

Published at Apr 6, 2021 Computer Vision Vectorization

Connoisseur: Provenance Analysis in Paintings (MSc dissertation)

A comparative analysis of multiple convolutional networks-based strategies to identify and classify art-related digital artifacts. In a first stage, we conduct our experiments over the VGDB2016 dataset, comprising art pieces from Vincent van Gogh and his peers. We then expand our strategy to a broader multi-class scenario, seeking to distinguish paintings from 1,584 different authors.

Published at Sep 23, 2019

Rede Neural Convolucional Paralelizada em PyCUDA

GPU implementations for the mathematical operations commonly employed in the development of convolutional networks.

Published at Dec 14, 2017 CUDA Portuguese

Redes Artificiais de Arquitetura Variante

Searching network architectures using Hill-Climbing and Genetic Algorithms.

Published at Dec 5, 2016 Portuguese Local Optimization Genetic Algorithms

Treinamento de redes neurais como um processo evolutivo

Exemplifying the training of neural networks as an evolutionary process. Network parameters are modeled as individuals and genetic algorithm is used to optimize the population accordingly.

Published at Jun 1, 2016 Portuguese Genetic Algorithms

A Study of the ISOMAP Algorithm and Its Applications in Machine Learning (Undergraduate final presentation)

Presentation of linear and non-linear classic dimensionality reduction methods.

Published at Dec 7, 2015 Dimensionality Reduction Manifold Learning ISOMAP

A Study of the ISOMAP Algorithm and Its Applications in Machine Learning (Undergraduate final report)

A study of the foundations of nonlinear dimensionality reduction through Manifold Learning.

Published at Dec 7, 2015 Dimensionality Reduction Manifold Learning ISOMAP

Educação e tecnologia: desafios para a construção de conhecimento por meio da computação

Será abordada a relação entre educação e computação, que se torna cada vez mais próxima. Mais precisamente, os objetos de aprendizagem, elementos essenciais nos processos de ensino e aprendizagem da educação a distância ou projetos de educação complementar.

Published at Jan 15, 2013 Portuguese Education


Events

17th International Conference on Computer Vision Theory and Applications (Feb. 2022)

"MinMax-CAM: Improving Focus of CAM-based Visualization Techniques in Multi-label Problems"

Speakerhttps://visapp.scitevents.org/?y=2022

IEEE Symposium Series on Computational Intelligence (Dec. 2021)

"Connoisseur: Provenance Analysis in Paintings," presented in the Applications of Deep Learning II track.

Speakerhttps://attend.ieee.org/ssci-2021/

The 19th International Conference on Computer Analysis of Images and Patterns (Sep. 2021)

"Authentication of Vincent van Gogh's Work," presented in the Biometrics, Cryprography and Security track.

Speakerhttps://cyprusconferences.org/caip2021/

Dextra's Data Week (Nov. 2020)

"Superpowers with Natural Language Processing," illustrating commercial cases for natural language processing techniques and algorithms.

Speakerhttps://www.dextra.com.br/

DevFest, GDG Campinas (Nov. 2018)

Participant in Computing Conference organized by GDG Campinas.

Participanthttps://gdg-campinas.github.io/devfest/

3rd Online National Congress on Mechanic Engineer and Automation (CONAENGE 2018)

Co-speaker for poster titled "Anomaly Detection and Failure Prediction in Industrial Machinery" (in Portuguese), describing the work performed at Solvian Tech for its multiple clients.

Co-Speakerhttps://conaenge.com.br/conaenge-2018/

SECOMP Unicamp 2017/2

Computing Week at Universidade Estadual de Campinas.

Organizerhttps://www.facebook.com/secompunicamp/

SECOMP UFScar 2015

Computing Week at Universidade Federal de São Carlos.

Speakerhttps://www.facebook.com/secompufscar/