SEMANTIC SEGMENTATION of BENTHIC COMMUNITIES from ORTHO-MOSAIC MAPS

Visual sampling techniques represent a valuable resource for a rapid, non-invasive data acquisition for underwater monitoring purposes.Long-term monitoring projects usually requires the collection of large quantities of data, and the visual analysis of a human expertoperator remains, in this context, a very time consuming task. It has been estimated that only the 1-2%of the acquired images are lateranalyzed by scientists (Beijbom et al., 2012). Strategies for the automatic recognition of benthic communities are required to effectivelyexploit all the information contained in visual data. Supervised learning methods, the most promising classification techniques in thisfield, are commonly affected by two recurring issues: the wide diversity of marine organism, and the small amount of labeled data.In this work, we discuss the advantages offered by the use of annotated high resolution ortho-mosaics of seabed to classify and segmentthe investigated specimens, and we suggest several strategies to obtain a considerable per-pixel classification performance although theuse of a reduced training dataset composed by a single ortho-mosaic. The proposed methodology can be applied to a large number ofdifferent species, making the procedure of marine organism identification an highly adaptable tas

Marching Intersections: An Efficient Approach to Shape-from-Silhouette

A new shape-from-silhouette algorithm for the creation of 3D digital models is presented. The algorithm is based on the use of the Marching Intersection (MI) data structure, a volumetric scheme which allows ef\ufb01cient representation of 3D polyhedra and reduces the boolean operations between them to simple boolean operations on linear intervals. MI supports the de\ufb01nition of a direct shape-from-silhouette approach: the 3D conoids built from the silhouettes extracted from the images of the object are directly intersected to form the resulting 3D digital model. Compared to existing methods, our approach allows high quality models to be obtained in an ef\ufb01cient way. Examples on synthetic objects together with quantitative and qualitative evaluations are given

Gestione del dato archeologico tridimensionale via web: l’esperienza con il software 3DHOP

3D Heritage Online Presenter (3DHOP) is a framework for advanced web-based visual presentations of high-resolution 3D content. Developed at the Visual Computing Lab CNR ISTI, 3DHOP was designed to cope with the specific needs of cultural heritage projects, supporting web-based publishing of very high-resolution digitized results and enabling the documentation of complex restoration actions. The present paper highlights, through some case studies (Peltuinum archaeological area, AQ, and Castillo de La Muela in Consuegra), the potentials of 3DHOP’s tools for the management of data from both active (laser scanner) and passive sensors (photogrammetry and aerophotogrammetry). In addition, problems and solutions encountered during the organization and personalization of web pages will be presented. The goal of this operation is to create a three-dimensional hub that can collect and link traditional archaeological documentation to 3D geometry

Data Fusion of Objects Using Techniques Such as Laser Scanning, Structured Light and Photogrammetry for Cultural Heritage Applications

In this paper we present a semi-automatic 2D-3D local registration pipeline capable of coloring 3D models obtained from 3D scanners by using uncalibrated images. The proposed pipeline exploits the Structure from Motion (SfM) technique in order to reconstruct a sparse representation of the 3D object and obtain the camera parameters from image feature matches. We then coarsely register the reconstructed 3D model to the scanned one through the Scale Iterative Closest Point (SICP) algorithm. SICP provides the global scale, rotation and translation parameters, using minimal manual user intervention. In the final processing stage, a local registration refinement algorithm optimizes the color projection of the aligned photos on the 3D object removing the blurring/ghosting artefacts introduced due to small inaccuracies during the registration. The proposed pipeline is capable of handling real world cases with a range of characteristics from objects with low level geometric features to complex ones

A sombra do arquitecto, da colaboração entre João Andresen e Teófilo Rego

Do levantamento do espólio do fotógrafo Teófilo Rego podemos concluir que dos vários profissionais da “Escola do Porto” com quem colaborou intensivamente entre as décadas de 1940 e 1960, a figura que mais se destaca é sem dúvida a do arquitecto João Andresen (1920/67). Como nenhum outro, o lote das imagens da obra deste autor revela de facto, pela quantidade e diversidade do material fotográfico, uma colaboração regular, sem igual, que abrange um número considerável dos seus trabalhos, desde o projecto que apresenta ao concurso para o Monumento ao Infante D. Henrique (1954/56) ao Plano de Desenvolvimento Turístico dos Reis Magos na ilha da Madeira (1964). A comunicação passa em revista as diversas reportagens que Rego realizou das obras e projectos de Andresen, aborda as histórias, as razões e os motivos que estão na sua origem, demonstrando como desde cedo a fotografia constituiu para os profissionais portugueses um instrumento imprescindível tanto na elaboração de arquivos de memória pessoal como na divulgação e apresentação dos seus trabalhos em concursos, exposições e revistas, ou ainda como meio de comunicação e suporte das ideias que pretendiam afirmar.Este texto foi co-financiado pela Fundação para a Ciência e a Tecnologia I.P. (PIDDAC) e pelo Fundo Europeu de Desenvolvimento Regional – FEDER, através do COMPETE – Programa Operacional Fatores de Competitividade (POFC), no âmbito do projecto "Fotografia, Arquitectura Moderna e a «Escola do Porto»: Interpretações em torno do Arquivo Teófilo Rego" (PTDC/ATP-AQI/4805/2012

Seasonality of the antibiotic resistance gene blaCTX-M in temperate Lake Maggiore

The beta lactamase gene blaCTX-M, responsible of the resistance to cephalosporins, has been detected in microbes from hospitals to open waters. We studied the seasonality and stability of blaCTX-M in Lake Maggiore over 3 years and the role of potential inputs of allochthonous bacteria and/or antibiotic pollution in promoting its occurrence. blaCTX-M was mainly present from January to July in the pelagic microbial community and the gene occurrence was significantly related to low water temperature. To evaluate its temporal stability in the bacterial community over a short period, we measured blaCTX-M daily over the course of 6 days. The gene was below the limit of quantification except for one sampling when its abundance peaked, suggesting a point contamination. The bacterial community of the lake in which blaCTX-M was detected suggests that at least two distinct bacterial populations contained the gene. The occurrence of known blaCTX-M containing genera and the occurrence of the gene, however, did not overlap. Furthermore, the experimental addition of cefotaxime to lake water incubations did not promote abundance of the gene. These data imply that blaCTX-M was present in the environmental microbial community. Increases of gene abundances were likely caused by environmental parameters other than antibiotic contamination

SEMANTIC SEGMENTATION OF BENTHIC COMMUNITIES FROM ORTHO-MOSAIC MAPS

Visual sampling techniques represent a valuable resource for a rapid, non-invasive data acquisition for underwater monitoring purposes. Long-term monitoring projects usually requires the collection of large quantities of data, and the visual analysis of a human expert operator remains, in this context, a very time consuming task. It has been estimated that only the 1-2% of the acquired images are later analyzed by scientists (Beijbom et al., 2012). Strategies for the automatic recognition of benthic communities are required to effectively exploit all the information contained in visual data. Supervised learning methods, the most promising classification techniques in this field, are commonly affected by two recurring issues: the wide diversity of marine organism, and the small amount of labeled data. In this work, we discuss the advantages offered by the use of annotated high resolution ortho-mosaics of seabed to classify and segment the investigated specimens, and we suggest several strategies to obtain a considerable per-pixel classification performance although the use of a reduced training dataset composed by a single ortho-mosaic. The proposed methodology can be applied to a large number of different species, making the procedure of marine organism identification an highly adaptable task.</p

3D DIGITIZATION OF AN HERITAGE MASTERPIECE - A CRITICAL ANALYSIS ON QUALITY ASSESSMENT

Despite being perceived as interchangeable when properly applied, close-range photogrammetry and range imaging have both their pros and limitations that can be overcome using suitable procedures. Even if the two techniques have been frequently cross-compared, critical analysis discussing all sub-phases of a complex digitization project are quite rare. Comparisons taking into account the digitization of a cultural masterpiece, such as the Etruscan Sarcophagus of the Spouses (Figure 1) discussed in this paper, are even less common. The final 3D model of the Sarcophagus shows impressive spatial and texture resolution, in the order of tenths of millimetre for both digitization techniques, making it a large 3D digital model even though the physical size of the artwork is quite limited. The paper presents the survey of the Sarcophagus, a late 6th century BC Etruscan anthropoid Sarcophagus. Photogrammetry and laser scanning were used for its 3D digitization in two different times only few days apart from each other. The very short time available for the digitization was a crucial constraint for the surveying operations (due to constraints imposed us by the museum curators). Despite very high-resolution and detailed 3D models have been produced, a metric comparison between the two models shows intrinsic limitations of each technique that should be overcome through suitable onsite metric verification procedures as well as a proper processing workflow

MeshLab

MeshLab the open source system for processing and editing 3D triangular meshes. It provides a set of tools for editing, cleaning, healing, inspecting, rendering, texturing and converting meshes. It offers features for processing raw data produced by 3D digitization tools/devices and for preparing models for 3D printing. With over 2 millions download, MeshLab is a de-fact standard tool in for mesh processing