Search results for "SCANNER"
showing 10 items of 170 documents
Facial scanning accuracy depending on the alignment algorithm and digitized surface area location: An in vitro study.
2021
To measure the accuracy (trueness and precision) of a facial scanner depending on the alignment method and the digitized surface area location.Fourteen markers were adhered on a head mannequin and digitized using an industrial scanner (GOM Atos Q 3D 12 M; Carl Zeiss Industrielle Messtechnik GmbH). A control mesh was acquired. Subsequently, the mannequin was digitized using a facial scanner (Arc4; Bellus3D) (n = 30). The control mesh was delineated into 10 areas. Based on the alignment procedures, two groups were created: reference best fit (RBF group) and landmark-based best fit (LA group). The root mean square was used to calculate the discrepancy between the control mesh and each facial s…
Land surface emissivity retrieval from airborne sensor over urban areas
2012
Abstract In this paper we compare three different methodologies to retrieve land surface emissivity (LSE) over urban areas: the NDVI thresholds method, the temperature and emissivity separation (TES) algorithm and the temperature independent spectral indices (TISI) algorithm. The methodologies were applied to the Airborne Hyperspectral Scanner (AHS) imagery acquired during the Dual-use European Security IR Experiment 2008 (DESIREX 2008) experimental campaign over the city of Madrid (Spain). The images have a spatial resolution of 4 m. The retrieved values are compared to in situ data measured during the campaign at 4 sites. Results show a good performance of the TISI and the TES algorithms …
Rilievo integrato presso il Borgo Schirò (PA)
2013
Il lavoro qui presentato consiste in un rilievo integrato (Topografico/GPS statico/NRTK/Laser Scanner) di un piccolo contesto extraurbano siciliano, Borgo Schirò, noto per le vicende storiche che portarono alla sua costruzione a seguito dell’emanazione della legge n.1 del 2 gennaio 1940, per il superamento del latifondo. Data la natura varia degli elementi da rilevare (edifici, arredo urbano, strade) sono state adottate tecniche di acquisizione diversificate per ognuno di essi, le quali, in forma integrata, hanno permesso un utile confronto finale degli elaborati prodotti, offrendo la possibilità di effettuare analisi qualitative altamente accurate su singoli casi strutturali ed elevati gra…
Three-dimensional phase unwrapping using the Hungarian algorithm.
2009
We propose a three-dimensional phase unwrapping technique that uses the Hungarian algorithm to join together all the partial residual loops that may occur in a wrapped phase volume. Experimental results have shown that the proposed algorithm is more robust and reliable than other well-known three-dimensional phase unwrapping algorithms. Additionally, the proposed algorithm is fast in terms of computational complexity, which makes it suitable for practical applications.
Aiding phase unwrapping by increasing the number of residues in two-dimensional wrapped-phase distributions.
2015
In phase unwrapping residues are points of locally inconsistent phase that occur within a wrapped-phase map, which are usually regarded as being problematic for phase-unwrapping algorithms. Real phase maps typically contain a number of residues that are approximately proportional to the subsequent difficulty in unwrapping the phase distribution. This paper suggests the radical use of the discrete Fourier transform to actually increase the number of residues in 2D phase-wrapped images that contain discontinuities. Many of the additional residues that are artificially generated by this method are located on these discontinuities. For example, in fringe projection systems, such phase discontin…
MRI of tarantulas: morphological and perfusion imaging.
2005
This paper describes a study performed to evaluate the feasibility of using a 1.5-T whole-body magnetic resonance imaging (MRI) equipment, in combination with pharmacokinetic modeling, to obtain in vivo information about the morphology and perfusion of tarantulas (Eurypelma californicum). MRI was performed on three tarantulas using spin-echo sequences for morphological imaging and a rapid spoiled gradient-echo sequence for dynamic imaging during and after contrast medium (CM; Gd-DTPA) injection. Signal enhancement in dynamic measurements was evaluated with a pharmacokinetic two-compartment model. Spin-echo images showed morphological structures well. Dynamic images were of sufficient qualit…
Integrating topographic, photogrammetric and laser scanning techniques for a scan-to-bim process
2021
Abstract. The preservation of historic buildings can often be particularly difficult due to the lack of detailed information about architectural features, construction details, etc.. However, in recent years considerable technological innovation in the field of Architecture, Engineering, and Construction (AEC) has been achieved by the Building Information Modeling (BIM) process. BIM was developed as a methodology used mainly for new construction but, given its considerable potential, this approach can also be successfully used for existing buildings, especially for buildings of historical and architectural value. In this case, it is more properly referred to as Historic – or Heritage – Buil…
Surveying in the Valley of the Temples
2014
Full-waveform terrestrial laser scanning enables high-precision 3D topographic modelling of unstable rock valleys that is valuable for various geomorphological investigations. The area below the archaeological site of Temple of Juno in Agrigento, Sicily, is characterised by the presence of large sections of rock that have fallen down from the upper ridge. In this context, full-waveform laser scanning technology was tested for the production of a highly detailed 3D topographic model at two resolutions (2cm and 20cm) for simulating potential rockfall paths at the site.
In vivo evaluation of three-dimensional of volumetric changes using a CAD/CAM chair-side system : technical procedure
2017
An intraoral digital scanner in combination with specialized three-dimensional surface analysis software monitors volumetric changes to soft tissues or dental restorations. This technology can evaluate the success of a specific technique or medium- or long-term clinical outcomes in both clinical and research situations. This article describes how this technology was used to provide immediate chair-side data analysis without the help of specialized laboratory support. Key words:Intraoral scanner, CAD-CAM, best fit-method, surface tessellation language.
The Technologies of Architectural Survey: A New Comparison Based on the Tower of Sotillo de la Ribera, Burgos
2017
The paper offers an original research about the analysis and the comparison of different techniques of survey concerning the architectural field – image-based and range-based – throughout the development of the theory of errors in order to evaluate reliability and precision of the results. In particular, this analysis will be focused on the tower of the parochial Church of Santa Águeda, a building located in the small village of Sotillo de la Ribera, within the province of Burgos (Spain). The first part of this work, therefore, has been submitted to the implementation of different methodologies, from the direct survey used as a basis, to the procedure to represent graphically the results (e…