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Detalhes

Detalhes

  • Nome

    Marta Campos Ferreira
  • Cargo

    Investigador Sénior
  • Desde

    01 janeiro 2014
Publicações

2024

Hybrid time-spatial video saliency detection method to enhance human action recognition systems

Autores
Gharahbagh, AA; Hajihashemi, V; Ferreira, MC; Machado, JJM; Tavares, JMRS;

Publicação
MULTIMEDIA TOOLS AND APPLICATIONS

Abstract
Since digital media has become increasingly popular, video processing has expanded in recent years. Video processing systems require high levels of processing, which is one of the challenges in this field. Various approaches, such as hardware upgrades, algorithmic optimizations, and removing unnecessary information, have been suggested to solve this problem. This study proposes a video saliency map based method that identifies the critical parts of the video and improves the system's overall performance. Using an image registration algorithm, the proposed method first removes the camera's motion. Subsequently, each video frame's color, edge, and gradient information are used to obtain a spatial saliency map. Combining spatial saliency with motion information derived from optical flow and color-based segmentation can produce a saliency map containing both motion and spatial data. A nonlinear function is suggested to properly combine the temporal and spatial saliency maps, which was optimized using a multi-objective genetic algorithm. The proposed saliency map method was added as a preprocessing step in several Human Action Recognition (HAR) systems based on deep learning, and its performance was evaluated. Furthermore, the proposed method was compared with similar methods based on saliency maps, and the superiority of the proposed method was confirmed. The results show that the proposed method can improve HAR efficiency by up to 6.5% relative to HAR methods with no preprocessing step and 3.9% compared to the HAR method containing a temporal saliency map.

2024

Estimating Alighting Stops and Transfers from AFC Data: The Case Study of Porto

Autores
Hora, J; Ferreira, MC; Camanho, A; Galvão, T;

Publicação
Lecture Notes in Networks and Systems

Abstract

2024

Qualitative Data Analysis in the Health Sector

Autores
Veloso, M; Ferreira, MC; Tavares, JMRS;

Publicação
Lecture Notes in Networks and Systems

Abstract

2024

Gamification in Mobile Ticketing Systems: A Review

Autores
Ferreira, MC; Gouveia, D; Dias, TG;

Publicação
Lecture Notes in Networks and Systems

Abstract

2024

Analyzing Quality of Service and Defining Marketing Strategies for Public Transport: The Case of Metropolitan Area of Porto

Autores
Ferreira, MC; Peralo, G; Dias, TG; Tavares, JMRS;

Publicação
Lecture Notes in Networks and Systems

Abstract

Teses
supervisionadas

2018

Monitoring a Mobile Ticketing System Based on NFC and BLE Beacons

Autor
José Miguel Botelho Mendes

Instituição
UP-FEUP

2018

Development and testing of a personalized recommender system based on mobility profile analysis and passenger activity

Autor
Luís Miguel Azevedo Duarte

Instituição
UP-FEUP

2018

Usability Evaluation Methodology for Public Transport Mobile Ticketing Solutions

Autor
Daniel Meireles de Amorim

Instituição
UP-FEUP