Ana Paula Brandão Lopes

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In this paper, we present a content-based image retrieval system designed to retrieve mammographies from large medical image database. The system is developed based on breast density, according to the four categories defined by the American College of Radiology, and is integrated to the database of the Image Retrieval in Medical Applications (IRMA) project,(More)
Most of previous papers about the detection of nude or pornographic images start by the application of a skin detector followed by some kind of shape or geometric model-ing. In this work, these two steps are avoided by a bag-of-features (BOF) approach, in which images are represented by histograms of sparse visual descriptors. BOF approaches have been(More)
This paper presents a survey of human action recognition approaches based on visual data recorded from a single video camera. We propose an organizing framework which puts in evidence the evolution of the area, with techniques moving from heavily constrained motion capture scenarios towards more challenging , realistic, " in the wild " videos. The proposed(More)
—The ability to filter improper content from mul-timedia sources based on visual content has important applications , since text-based filters are clearly insufficient against erroneous and/or malicious associations between text and actual content. In this paper, we investigate a method for detection of nudity in videos based on a bag-of-visual-features(More)
—The strategies for the preservation of historical documents can include their digitization, which is an effective way to make them publicly available while preventing degradation of the original sources. The Arquivo P ´ ublico Mineiro (APM), the Archives of the State of Minas Gerais, has a collection of historical photographs from Brazil, and some of them(More)
—The recognition of human actions from videos has several interesting and important applications, and a vast amount of different approaches has been proposed for this task in different settings. Such approaches can be broadly categorized in model-based and model-free. Typically, model-based approaches work only in very constrained settings, and because of(More)
—Bag-of-Visual-Features (BoVF) representations have achieved a great success when used for object recognition, mainly because of their robustness to several kinds of variations and occlusion. Recently, a number of BoVF approaches has been proposed also for recognition of human actions from videos. One important issue that arises when using BoVF for videos(More)
In this work, we propose a 2D-PCA based face recognizer as a semi-automatic tool for helping indexing people in historical photographs. In the proposed recognizer we cope with the scarcity of training samples and the lack of precision of the detector using a training scheme in two stages. The first stage uses an external face database to compute an average(More)
In this paper, we present a content-based image retrieval (CBIR) system called MammoSVD. This CBIR system is developed based on breast density – fatty or dense, and the database used, from the IRMA project, provides images with the ground truth already set. Singular value decomposition (SVD) is proposed for the breast density characterization by the(More)