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Master's Dissertation
DOI
https://doi.org/10.11606/D.45.2021.tde-16122021-182010
Document
Author
Full name
Antonio Augusto Abello
E-mail
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2021
Supervisor
Committee
Hirata Junior, Roberto (President)
Gomes, David Menotti
Wang, Zhangyang
Title in English
Two studies on Convolutional Neural Networks sensibility to resolution
Keywords in English
Deep learning
Face recognition
Super resolution
Abstract in English
Convolutional Neural Networks (CNNs) recently became the state-of-the-art for various Computer Vision tasks. However, for reasons not completely understood, they are very sensitive to low resolution images. This can be troublesome as real life applications such as automated driving or surveillance can not use high resolution sensors. In this work we perform two studies on this subject matter: on the first we empirically study the effect of resolution loss and image restoration algorithms on a Face Recognition model. On the second, we study the high frequency bias hypothesis, one of the current possible explanations for CNNs sensitivity. We are able to develop new techniques for image restoration that better deal with the low resolution recognition problem and advance the understanding of the high frequency bias in CNNs.
Title in Portuguese
Dois estudos sobre a sensibilidade de Redes Neurais Convolucionais à resolução
Keywords in Portuguese
Deep learning
Reconhecimento facial
Super-resolução
Abstract in Portuguese
Redes Neurais Convolucionais (CNNs) recentemente se tornaram o estado-da-arte em várias áreas de Visão Computacional (CV). No entanto, por razões não completamente conhecidas, elas são bastante sensíveis à imagens de baixa resolução. Isso pode se tornar um problema para aplicações no mundo real, uma vez que para casos como o de vigilância ou direção automatizada nem sempre sensores de alta resolução podem ser utilizados. Neste trabalho conduzimos dois estudos sobre esse assunto: no primeiro estudamos empíricamente o efeito de perda de resolução e do uso de algoritmos de restauração de imagens em um modelo de Reconhecimento Facial (FR). No segundo, estudamos a hipótese do viés para altas frequências, uma das possíveis explicações para a sensibilidade de CNNs. No trabalho conseguimos desenvolver novas técnicas de restauração que ajudam melhor no problema de reconhecimento em baixa resolução e aprofundamos o entendimento atual sobre viés para altas frequências em CNNs.
 
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tese_Abello.pdf (7.79 Mbytes)
Publishing Date
2022-02-09
 
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