46 documents found, page 1 of 5
Application of a self-supervised learning technique for monitoring industrial s...
Magalhães, V.; Costa, M. Fernanda P.; Ferreira, Manuel João Oliveira; Pinto, T.; Figueiredo, V.Supervised learning has reached a bottleneck as they require expensive and time-consuming annotations. In addition, in some problems, such as in industrial spaces, it is not always possible to acquire a large number of images. Self-supervised learning helps these issues by extracting information from the data itself, without requiring labels and has achieved good performance, closing the gap between supervised ...
Quality evaluation of digital fundus images through combined measures
Veiga, Diana; Pereira, Carla; Ferreira, Manuel João Oliveira; Gonçalves, Luís; Monteiro, João L.The evaluation of image quality is an important step before an automatic analysis of retinal images. Several conditions can impair the acquisition of a good image, and minimum image quality requirements should be present to ensure that an automatic or semiautomatic system provides an accurate diagnosis. A method to classify fundus images as low or good quality is presented. The method starts with the detection ...
Using a multi-agent system approach for microaneurysm detection in fundus images
Pereira, Carla; Veiga, Diana; Mahdjoub, Jason; Guessoum, Zahia; Gonçalves, Luís; Ferreira, Manuel João Oliveira; Monteiro, João L.Objective Microaneurysms represent the first sign of diabetic retinopathy, and their detection is fundamental for the prevention of vision impairment. Despite several research attempts to develop an automated system to detect microaneurysms in fundus images, none has shown the level of performance required for clinical practice. We propose a new approach, based on a multi-agent system model, for microaneurysm s...
Focus evaluation approach for retinal images
Veiga, Diana; Pereira, Carla; Ferreira, Manuel João Oliveira; Gonçalves, Luís; Monteiro, João L.Digital fundus photographs are often used to provide clinical diagnostic information about several pathologies such as diabetes, glaucoma, macular degeneration and vascular and neurologic disorders. To allow a precise analysis, digital fundus image quality should be assessed to evaluate if minimum requirements are present. Focus is one of the causes of low image quality. This paper describes a method that autom...
Blood vessel detection in fundus images by a multi-agent approach
Pereira, Carla; Mahdjoub, Jason; Guessoum, Zahia; Gonçalves, Luís; Ferreira, Manuel João OliveiraThe segmentation of retinal blood vessels by digital color fundus images analysis is crucial for several medical diagnostic systems, such as the diabetic retinopathy early diagnosis. This pathology has been shown to be the most common cause of blindness among working age people in developed countries. Several interesting approaches have been done in segmenting the blood vessels by image processing techniques ap...
Small red lesions detection using a MAS approach
Pereira, Carla; Veiga, Diana; Mahdjoub, Jason; Guessoum, Zahia; Gonçalves, Luís; Ferreira, Manuel João Oliveira; Monteiro, João L.Microaneurysms are the diabetic retinopathy rst sign and its early detection is crucial for blindness prevention. Several approaches can be found in literature for the automatic microaneurysm segmentation, but none of them has shown the required performance. In this study, a new approach is proposed based on an organization of agents enabling microaneurysms segmentation. This multiagent model is preceded by a p...
Retinal blood vessel segmentation by a MAS approach
Pereira, Carla; Mahdjoub, Jason; Guessoum, Zahia; Gonçalves, Luís; Ferreira, Manuel João OliveiraRetinal blood vessels segmentation by color fundus images analysis has got huge importance for the diabetic retinopathy early diagnosis. Several interesting computational approaches have been done in this field, but none of them has shown the required performance due to the use of global approaches. Therefore, a new approach is proposed based on an organization of agents enabling vessels detection. This multi-a...
Relatório de acompanhamento do projecto RHEUMUS (sistema de análise de imagens ...
Ferreira, Manuel João Oliveira; Martins, TeresaO projeto RHEUMUS tem como principal objetivo o desenvolvimento de um sistema de processamento e análise de imagens de ecografia para a área da reumatologia. A solução em desenvolvimento será composta por um conjunto de ferramentas computacionais capazes de identificar, segmentar e quantificar estruturas anatómicas normais/patológicas do sistema músculo-esquelético da mão e do joelho, baseadas na tecnologia de ...
Optic disc detection in color fundus images using ant colony optimization
Pereira, Carla Susana Correia; Gonçalves, Luís; Ferreira, Manuel João OliveiraDiabetic retinopathy has been revealed as the most common cause of blindness among people of working age in developed countries. However, loss of vision could be prevented by an early detection of the disease and, therefore, by a regular screening program to detect retinopathy. Due to its characteristics, the digital color fundus photographs have been the easiest way to analyze the eye fundus. An important prer...
Using MAS to detect retinal blood vessels
Pereira, Carla; Mahdjoub, Jason; Guessoum, Zahia; Gonçalves, Luís; Ferreira, Manuel João OliveiraThe segmentation of retinal vasculature by color fundus images analysis is crucial for several medical diagnostic systems, such as the diabetic retinopathy early diagnosis. Several interesting approaches have been done in this field but the obtained results need to be improved. We propose therefore a new approach based on an organization of agents. This multi-agent approach is preceded by a preprocessing phase ...