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| Registros recuperados: 15 | |
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| Istenič, Klemen; Gracias, Nuno; Arnaubec, Aurelien; Escartín, Javier; Garcia, Rafael. |
| Improvements in structure-from-motion techniques are enabling many scientific fields to benefit from the routine creation of detailed 3D models. However, for a large number of applications, only a single camera is available for the image acquisition, due to cost or space constraints in the survey platforms. Monocular structure-from-motion raises the issue of properly estimating the scale of the 3D models, in order to later use those models for metrology. The scale can be determined from the presence of visible objects of known dimensions, or from information on the magnitude of the camera motion provided by other sensors, such as GPS. This paper addresses the problem of accurately scaling 3D models created from monocular cameras in GPS-denied environments,... |
| Tipo: Text |
Palavras-chave: Structure-from-motion; Underwater 3D reconstruction; Photogrammetry; Laser scalers. |
| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00591/70338/68394.pdf |
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| Barde, J.; Bonhommeau, Sylvain; Chassot, E.; Motah, B.. |
| ollecting data on aquatic biodiversity is very challenging because of the difficulty to access underwater ecosystems. Over the years, field surveys have become easier and cheaper with the development of low cost electronics. Commercial and recreational vessels, including sailboats, can now substantially complement expensive scientific surveys and arrays of observation buoys deployed across the world oceans (Pesant et al., 2015, Karsenti et al., 2011). Meanwhile, a large variety of marine animals such as birds, mammals, and fish have become data collection platforms for both biological and environmental parameters through the advent of archival tags. It becomes obvious that data collection in coastal and high seas will become more popular and that citizen... |
| Tipo: Text |
Palavras-chave: Citizen science; Ocean and coastal observing systems; Surfing; Action cameras; Coral reef mapping; Photogrammetry; Deep learning; R. |
| Ano: 2018 |
URL: http://archimer.ifremer.fr/doc/00450/56164/57712.pdf |
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| Sacco,I.C.N.; Picon,A.P.; Ribeiro,A.P.; Sartor,C.D.; Camargo-Junior,F.; Macedo,D.O.; Mori,E.T.T.; Monte,F.; Yamate,G.Y.; Neves,J.G.; Kondo,V.E.; Aliberti,S.. |
| The aim of this study was to investigate the influence of image resolution manipulation on the photogrammetric measurement of the rearfoot static angle. The study design was that of a reliability study. We evaluated 19 healthy young adults (11 females and 8 males). The photographs were taken at 1536 pixels in the greatest dimension, resized into four different resolutions (1200, 768, 600, 384 pixels) and analyzed by three equally trained examiners on a 96-pixels per inch (ppi) screen. An experienced physiotherapist marked the anatomic landmarks of rearfoot static angles on two occasions within a 1-week interval. Three different examiners had marked angles on digital pictures. The systematic error and the smallest detectable difference were calculated from... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Physical therapy modalities; Photogrammetry; Reliability; Rearfoot angle. |
| Ano: 2012 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2012000900003 |
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| Bertin, Stephane; Friedrich, Heide. |
| Gravel riverbeds naturally present a range of sediment size that can span several orders of magnitude. However, fine sediment (i.e., size <2 mm) additions affect sediment transport and are potentially harmful to the river ecology. Limited research has been done to understand the effects of sand addition on gravel bed topography. For this study, we conducted flume experiments testing the effectiveness of topography remote sensing to measure the response of a water-worked gravel bed to varying sand additions and bed flushing. Repeated measurements of the bed topography with through-water photogrammetry show that sand deposits primarily in low-lying areas of the bed, where it is sheltered. Observed changes in bed elevation standard deviation, skewness, and... |
| Tipo: Text |
Palavras-chave: Gravel bed; Sand addition; Bed flushing; DEM; Roughness; Photogrammetry. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00637/74905/75969.pdf |
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| Fabri, Marie-claire; Vinha, Beatriz; Allais, Anne-gaelle; Bouhier, Marie-edith; Dugornay, Olivier; Gaillot, Arnaud; Arnaubec, Aurelien. |
| Cold-water coral ecosystems have been identified as vulnerable, but quantitative data on their conservation status is very limited. The Marine Strategy Framework Directive (MSFD) is the tool implemented by the European Union’s Integrated Maritime Policy to achieve Good Environmental Status (GES) of marine waters by 2020. In this context, the aim of this study was to evaluate the Ecological Status of benthic habitats in Cassidaigne canyon, focusing in particular on cold-water coral habitats dominated by Madrepora oculata. Data were collected during the Videocor1 cruise (2017). Videos and photos collected during eight dives of the H-ROV Ariane were used to reconstruct, in 3-dimensions, the areas where cnidarians have settled in the canyon. A total of 33 3D... |
| Tipo: Text |
Palavras-chave: Biodiversity; Photogrammetry; Habitat mapping; Bauxite residues; Vulnerable marine ecosystems. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00511/62293/66719.pdf |
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| Jaud, Marion; Grasso, Florent; Le Dantec, Nicolas; Verney, Romaric; Delacourt, Christophe; Ammann, Jerome; Deloffre, Julien; Grandjean, Philippe. |
| Intertidal mudflats play a critical role in estuarine exchange, connecting marine and continental supplies of nutrients and sediments. However, their complex morphodynamics, associated with a wide range of physical and biological processes, are still poorly understood and require further field investigation. In addition, mudflats are challenging areas for Structure-from-Motion (SfM) photogrammetric surveys. Indeed, the mudflats generally hold back residual tidal water, which can make stereo restitution particularly difficult because of poor correlations or sun-glint effects. This study aims to show the potential of light UAVs (Unmanned Aerial Vehicles) for monitoring sedimentary hydrodynamics at different spatial scales in a silty estuary. For each UAV... |
| Tipo: Text |
Palavras-chave: Coastal monitoring; Unmanned Aerial Vehicle; Photogrammetry; Estuary; Mudflat areas; Morphological features. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00326/43721/43167.pdf |
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| Urbina-barreto, Isabel; Chiroleu, Frédéric; Pinel, Romain; Fréchon, Louis; Mahamadaly, Vincent; Elise, Simon; Kulbicki, Michel; Quod, Jean-pascal; Dutrieux, Eric; Garnier, Rémi; Henrich Bruggemann, J.; Penin, Lucie; Adjeroud, Mehdi. |
| Structural complexity plays a key role in the functioning of coral reef ecosystems. Reef-building corals are major contributors to this complexity, providing shelter and food for numerous invertebrates and fish species. Both structural complexity and shelter capacity of reefscapes are determined by several components such as spurs and grooves, slope, caves and holes, vegetation and coral colonies. Quantifying the shelter capacity from coral colonies to reefscapes is a fundamental step to estimating ecosystem potential to support biodiversity. Here, we applied underwater photogrammetry to quantify shelter volumes provided by individual coral colonies. Overall, 120 3D models of coral colonies from branching, massive, columnar and tabular growth forms were... |
| Tipo: Text |
Palavras-chave: Coral reefs; Reef-building corals; Photogrammetry; 3D models; Predictive models; Shelter capacity; Structural complexity; Coral growth forms. |
| Ano: 2021 |
URL: https://archimer.ifremer.fr/doc/00659/77065/78372.pdf |
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| Troncoso Pazos,Jorge Andrés; Suazo Galdames,Iván Claudio; Cantín López,Mario; Zavando Matamata,Daniela Alejandra. |
| The nasal form is one of the most important aspects in assessing the facial aesthetics. Several authors have described changes in the form and nasal dimensions attributable to race and gender. The purpose of this study was to analyze the presence of sexual dimorphism in various morphometric parameters of the nose in a group of Chilean adults. This study involved 180 adults Chilean volunteers, 90 males and 90 females, between the age of 18 and 30 years which were conducted measurements of 12 parameters using indirect anthropometry, based on photographs from the front, profile and the nasal base, standardized, prosecuted through the program Corel Draw Graphics SuiteX3. Of the 12 dimensions nasal analyzed, significant differences were found between males and... |
| Tipo: Journal article |
Palavras-chave: Nose; Sexual dimorphism; Rhinoplasty; Anthropometry; Photogrammetry. |
| Ano: 2008 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022008000300005 |
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| Campos,João Batista. |
| The process of land occupation by the state of Paraná practically decimated its forests. Presently, only 7% from a total area of 83.41% is covered by forests. Most of them are now concentrated in the "Serra do Mar" and in the Iguaçu National Park. With regard to forest cover the most critical region is situated in the northwestern of the state with less than 1% of its area covered by forest. This restricted area mainly consists of conservation units and the islands of the high Paraná River floodplain. The present study consists of a spatial and multi-temporal analysis of deforestation and the quantification of the remnant forests on Porto Rico island (22º45'S; 53º15'W), which have their occupation history linked to the colonization process of the region.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Photogrammetry; Alluvial forest; Floodplain; Forest. |
| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89131999000100013 |
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| Populus, Jacques; Laurentin, Astrid; Rollet, Claire; Vasquez, Mickael; Guillaumont, Brigitte; Bonnot-courtois, Chantal. |
| This paper addresses the need for a finer description of coastal zone relief that is currently of interest for benthic habitat mapping. For example, the distribution of seaweed species in the tidal zone will mostly depend on the terrain's hypsometric level, slope and orientation. These parameters can be used in predictive distribution models, or more simply merged with 2.5/3D imagery to enhance interpretation. Since the required accuracy is of the order of 20-30 cm, two remote sensing techniques, lidar and photogrammetry, were examined and conditions for their application were assessed. Lidar surveys have been shown to provide such accuracy in all instances, whatever the substratum and vegetal cover type, as well as with the slope values currently... |
| Tipo: Text |
Palavras-chave: Laser scanning; Benthos mapping; Photogrammetry; Coastal zone topography. |
| Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-2278.pdf |
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| Registros recuperados: 15 | |
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