Search results for "Photogrammetry"
showing 10 items of 142 documents
Multitechnique diagnostic analysis and 3D surveying prior to the restoration of St. Michael defeating Evil painting by Mattia Preti
2021
In this study, a multimethodological analysis involving optical and physical/chemical diagnostic techniques and 3D photogrammetric survey was successfully applied, for the first time, on the large oil on canvas St. Michael defeating Evil painting by Mattia Preti, located inside the Church of the Immaculate Conception of Sarria (Floriana) in Malta. Pigmenting agents, binder media, and raw materials were first characterized, both at elemental and molecular scales, through X-ray fluorescence spectroscopy (XRF), optical stereo microscopy (SM), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), Fourier transform infrared spectroscopy (FT-IR), and gas chroma…
PERSPECTIVE RESTITUTION FROM VIEW CAMERAS PHOTOS
2022
Abstract. The paper aims at discussing the accuracy of perspective restitution from view camera photos; view cameras are non-standard cameras frequently used in the past century for on field shooting of buildings and urban sites; this is why the reconstruction of lost buildings often deals with photos taken with a view camera. The case study chosen for the proposed experiment is an urban complex built in Palermo in the ‘50s. The site features a very regular layout with surfaces at right angle, that supports the graphic reconstruction of photos’ inner and outer orientation. The site has been surveyed with a laser scanner; the point cloud provided the metric information needed for the evaluat…
3D mosaics survey: analysis of photogrammetric/computer vision approach in a metrological context
2016
The goal of the paper is evaluate photogrammetric/computer vision approach in a metrological context for 3D mosaics survey. The aim of the mosaics survey is the production of a full-scale representation (scale 1:1) useful for the documentation and for the restoration processes. In order to evaluate the optimal photogrammetric/computer vision workflow in this work three different surveys have been done for three mosaics with different size and location. Two of these are stored at Regional Archaeological Museum “Antonino Salinas” in Palermo (Italy) and the other one is stored at Regional Archaeological Museum “Baglio Anselmi” in Marsala (Italy). The research has allowed to show the potentiali…
Monoscopic Photogrammetry to Investigate the Buildings in the Period of Modernism in Salerno: The Case Study of Torquato Tasso High School
2021
The city of Salerno and the expansion that underwent in the 1920s in order to respond to the urban expansion following the demographic increase that occurred at the beginning of the century will be the topics discussed in this paper. Transformations that created a face to the city that, in its forms, although not linked to the most advanced avant-garde, represent a testimony of the new characteristics of the “modern” city. Within this evolutionary process of the province of Salerno there is the 1928 project of two engineers, Michele and his son Luigi De Angelis for the construction of the “Regio” School. In a first moment, several projects found in the archives refer mainly to the various l…
Impacts of wood extraction on soil: assessing rutting and soil compaction caused by skidding and forwarding by means of traditional and innovative me…
2021
AbstractIntensive forestry operations may cause soil compaction, plastic soil disturbances and rutting, which are responsible for undesirable effects on soils, vegetation and water bodies. Despite the numerous studies aimed to identify the main factors affecting soil damages, it still remains unclear whether wood extraction methods and driving direction (uphill or downhill) may affect the impacts of forest machines. This research analyses soil compaction and soil penetration resistance as well as rutting from forwarding and skidding using the same farm tractor in up- and downhill wood extraction. Rutting was estimated by 3D soil reconstruction derived by portable laser scanning (PLS) and cl…
Damage Indices and Photogrammetry for Decay Assessment of Stone-Built Cultural Heritage: The Case Study of the San Domenico Church Main Entrance Port…
2020
In recent decades, increasing attention is being paid to the multidisciplinary approach that allows the performance of both a preventive conservation and a more invasive restoration action. In this context, the present study aims to acquire information and data from field surveys undertaken in San Domenico Church, Southern Calabria, in order to provide a tool for the recording and the inventory of damage and decay phenomena, and assess their causes and scale. The subsequent calculation of damage indices also provided useful information in order to allow the prioritization of conservation and preservation responses.
Assessment of Classifiers and Remote Sensing Features of Hyperspectral Imagery and Stereo-Photogrammetric Point Clouds for Recognition of Tree Specie…
2018
Recognition of tree species and geospatial information on tree species composition is essential for forest management. In this study, tree species recognition was examined using hyperspectral imagery from visible to near-infrared (VNIR) and short-wave infrared (SWIR) camera sensors in combination with a 3D photogrammetric canopy surface model based on RGB camera stereo-imagery. An arboretum with a diverse selection of 26 tree species from 14 genera was used as a test area. Aerial hyperspectral imagery and high spatial resolution photogrammetric color imagery were acquired from the test area using unmanned aerial vehicle (UAV) borne sensors. Hyperspectral imagery was processed to calibrated …
A reverse engineering approach to measure the deformations of a sailing yacht
2016
In this work, a multidisciplinary experience, aimed to study the permanent deformations of the hull of a regatta sailing yacht is described. In particular, a procedure to compare two different surfaces of the hull of a small sailing yacht, designed and manufactured at the University of Palermo, has been developed. The first one represents the original CAD model while the second one has been obtained by means of a reverse engineering approach. The reverse engineering process was performed through an automatic close-range photogrammetry survey, that has allowed to obtain very accurate measures of the hull, and a 3D modelling step by the well-known 3D computer graphics software Rhinoceros. The…
Capturing gypsum rillenkarren morphometry by a 3D-photo reconstruction (3D-PR) technique
2020
Abstract Rillenkarren are small scale, straight, narrow solution channels that head at the crest of a bare rock slope and are extinguished downslope. In this paper the applicability of 3D-photo reconstruction technique of the rock surface is proposed for capturing the rillenkarren morphometry on gypsum. At first, the measurements are used to assess a relationship between the width/depth ratio and the depth of the rillenkarren. The exponent of this power relationship resulted different from the theoretical value - 0.5, confirming that the cross-section profiles of a rillenkarren can have a shape different from parabolic. The analysis developed for the cross-section area, the perimeter and th…
Finding Possible Weakness in the Runoff Simulation Experiments to Assess Rill Erosion Changes without Non-Intermittent Surveying Capabilities
2020
The Terrestrial Photogrammetry Scanner (TEPHOS) offers the possibility to precisely monitor linear erosion features using the Structure from Motion (SfM) technique. This is a static, multi-camera array and dynamically moves the digital videoframe camera designed to obtain 3-D models of rills before and after the runoff experiments. The main goals were to (1) obtain better insight into the rills