scholarly journals Cultural Heritage Restoration of a Hemispherical Vault by 3D Modelling and Projection of Video Images with Unknown Parameters and from Unknown Locations

2021 ◽  
Vol 11 (12) ◽  
pp. 5323
Author(s):  
Jose Herraez ◽  
Jose L. Denia ◽  
Enrique Priego ◽  
Pablo Navarro ◽  
Maria T. Martin ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Cultural Heritage ◽  
3D Modelling ◽  
3D Image ◽  
Surface Geometry ◽  
Unknown Parameters ◽  
Mathematical Development ◽  
Video Images ◽  
Virtual Images ◽  
Architectural Restoration

Reverse engineering applied to architectural restoration for the reconstruction of structural surfaces depends on metric precision. Sometimes there are elements on these surfaces whose value is even higher than the building itself. This is the case for many churches whose ceilings have pictorial works of art. Reconstruction requires the existence of some identifiable remainder and/or a surface geometry that enables mathematical development. In our case, the vault has an irregular hemispherical geometry (without possible mathematical development), and there are no significant remains of the painting (which was destroyed by a fire). Through the 3D modelling of the irregular vault and two historic frames with a camera of unknown geometry, an inverse methodology is designed to project the original painting without metric deformations. For this, a new methodology to locate the camera positions is developed. After, a 3D virtual mathematical model of the complete image on the vault is calculated, and from it, partial 3D virtual images are automatically calculated depending on the variable unknown positions of the video cannons (distributed along the upper corridor of the apse) that will project them (visually forming a perfect complete 3D image).

scholarly journals EFFICIENT USE OF VIDEO FOR 3D MODELLING OF CULTURAL HERITAGE OBJECTS

2015 ◽  
Vol II-3/W4 ◽  
pp. 1-8 ◽  
Author(s):  
B. Alsadik ◽  
M. Gerke ◽  
G. Vosselman
Keyword(s):  
Cultural Heritage ◽  
Rapid Development ◽  
3D Modelling ◽  
Image Resolution ◽  
Video Image ◽  
Short Baseline ◽  
Video Imaging ◽  
Video Images ◽  
Average Accuracy ◽  
Cultural Heritage Objects

Currently, there is a rapid development in the techniques of the automated image based modelling (IBM), especially in advanced structure-from-motion (SFM) and dense image matching methods, and camera technology. One possibility is to use video imaging to create 3D reality based models of cultural heritage architectures and monuments. Practically, video imaging is much easier to apply when compared to still image shooting in IBM techniques because the latter needs a thorough planning and proficiency. However, one is faced with mainly three problems when video image sequences are used for highly detailed modelling and dimensional survey of cultural heritage objects. These problems are: the low resolution of video images, the need to process a large number of short baseline video images and blur effects due to camera shake on a significant number of images. <br><br> In this research, the feasibility of using video images for efficient 3D modelling is investigated. A method is developed to find the minimal significant number of video images in terms of object coverage and blur effect. This reduction in video images is convenient to decrease the processing time and to create a reliable textured 3D model compared with models produced by still imaging. <br><br> Two experiments for modelling a building and a monument are tested using a video image resolution of 1920×1080 pixels. Internal and external validations of the produced models are applied to find out the final predicted accuracy and the model level of details. Related to the object complexity and video imaging resolution, the tests show an achievable average accuracy between 1 – 5 cm when using video imaging, which is suitable for visualization, virtual museums and low detailed documentation.

scholarly journals 3D IMAGE-BASED SURVEYING OF THE SAFE OF THE OBELLIO FIRMO <i>DOMUS</i> IN POMPEII

2020 ◽  
Vol XLIII-B2-2020 ◽  
pp. 1389-1394
Author(s):  
C. Francolini ◽  
V. A. Girelli ◽  
G. Bitelli
Keyword(s):  
Cultural Heritage ◽  
Structure From Motion ◽  
Three Dimensional ◽  
Interesting Case ◽  
3D Modelling ◽  
3D Image ◽  
Ancient City ◽  
Over Time

Abstract. This paper shows an application of image-based 3D modelling concerning an interesting case study in the field of Cultural Heritage, a safe located in the Obellio Firmo domus in Pompeii (Italy), one of the largest and most complex houses in the ancient city. The object was strongly deformed by the eruption of Vesuvius in 79 A.D. and is currently protected by a permanent glass that helps to preserve it over time. The surveying activities and processing methodology is explained, based on Multi-View Structure from Motion technique, as well as the unconventional solution adopted during the images acquisition. Finally, an attempt will be presented to reconstruct the hypothetical original three-dimensional appearance and shape of the safe.

scholarly journals THE DIGITAL O&P WORKSHOP

2021 ◽  
Vol 4 (2) ◽  
Author(s):  
Manuel Opitz ◽  
Peter Fröhlingsdorf
Keyword(s):  
Digital Health ◽  
3D Modelling ◽  
3D Image ◽  
Image Capture ◽  
Call To Action ◽  
Processing Step ◽  
The Impact ◽  
Near Future ◽  
Rapid Transformation ◽  
Health Experts

Digitalisation is the megatrend in healthcare, not only since the pandemic. We are two European digital health experts and industry leaders in the field of orthotics and prosthetics (O&P) and in this article we explored what are the underlying trends driving the adoption of digitalisation for customisation of prosthetics & orthotics. We showed that several trends in 3D image capture (input step), 3D modelling (processing step) and 3D printing (output step) currently converge and thus fuel the rapid transformation of the O&P industry. In short outlooks, we rated the probability and timing of adoption rates across the upcoming couple of years. We furthermore reviewed the impact of boundary conditions set by regulators as well as the reimbursement system. Towards the end of this article, we outlined a digital scenario of the near future by following around an orthotist during her work. We finished with a call-to-action targeting regulators, payors, prosthetists/orthotists, and patients to enable such a desirable future. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/36349/28332 How To Cite: Opitz M, Fröhlingsdorf P. The digital O&P workshop. Canadian Prosthetics & Orthotics Journal. 2021; Volume 4, Issue 2, No.15. https://doi.org/10.33137/cpoj.v4i2.36349 Corresponding Author: Manuel Opitz, MECURIS GmbH, Lindwurmstraße 11, 80337 München, Germany.E-Mail: [email protected] number: https://orcid.org/0000-0001-6098-1881

The Use of Composites in Architectural Restoration: Some Critical Considerations on the Theoretical Implications

2014 ◽  
Vol 624 ◽  
pp. 11-18
Author(s):  
Eva Coisson ◽  
Federica Ottoni
Keyword(s):  
Composite Materials ◽  
Cultural Heritage ◽  
Single Case ◽  
Single Case Study ◽  
New Materials ◽  
Technical Issues ◽  
The Many ◽  
Architectural Restoration ◽  
Theoretical Issues

The use of composites in the field of architectural restoration is becoming more and more widespread, because of the great technical advantages they convey in many cases. But applying these materials to the Cultural Heritage poses not only technical issues, common to all the applications on the same materials, but also artistic, historical and, more generally, cultural ones. The present paper faces these issues, starting with some considerations on how they were dealt with in history, when the “new” materials were iron, steel and reinforced concrete. Then, the specific problems posed by the composite materials are discussed and some examples are shown in order to identify the correct approach to the many different cases that can arouse in the field of architectural restoration. There isn’t a single right solution for each problem, but there is a right approach that starts from the comprehension of the building’s behavior, passes through a comparison of all the possible solutions and aims at finding the best equilibrium among the technical and theoretical issues for the single case study.

scholarly journals Minimal Camera Networks for 3D Image Based Modeling of Cultural Heritage Objects

Sensors ◽  
2014 ◽  
Vol 14 (4) ◽  
pp. 5785-5804 ◽  
Author(s):  
Bashar Alsadik ◽  
Markus Gerke ◽  
George Vosselman ◽  
Afrah Daham ◽  
Luma Jasim
Keyword(s):  
Cultural Heritage ◽  
Camera Networks ◽  
3D Image ◽  
Image Based Modeling ◽  
Cultural Heritage Objects

An Algorithm of Vortex Patches Identification Based on Models of Point Vortices

2020 ◽  
pp. 11-18
Author(s):  
V.N. Govorukhin
Keyword(s):  
Mathematical Model ◽  
Fluid Flow ◽  
Flow Region ◽  
Velocity Model ◽  
Point Vortices ◽  
Unknown Parameters ◽  
Vortex System ◽  
Vortex Patch ◽  
Finite Set ◽  
Set Of Points

An algorithm for identifying a plane vortex fluid flow from known velocity vectors at a finite set of points in the flow region is proposed. To describe the approximation of the vortex structure, a mathematical model of the system of point vortices is used. The parameters to be determined and characterizing the flow are the number of point vortices, their coordinates, and intensity. Unknown parameters are determined as a result of minimizing the functional that relates the known velocity vectors and the velocity model flows of the vortex system at the same points in the region. An implementation of the algorithm for the simplest case, one vortex patch, is presented. Computational experiments were carried out, which showed the effectiveness of the developed method.

Application of Stochastic Point-Based Rendering to Laser-Scanned Point Clouds of Various Cultural Heritage Objects

2018 ◽  
Vol 12 (3) ◽  
pp. 348-355 ◽  
Author(s):  
Kyoko Hasegawa ◽  
Liang Li ◽  
Naoya Okamoto ◽  
Shu Yanai ◽  
Hiroshi Yamaguchi ◽  
...  
Keyword(s):  
Image Quality ◽  
Cultural Heritage ◽  
Large Scale ◽  
Nearest Neighbor ◽  
Point Clouds ◽  
Visualization Method ◽  
3D Image ◽  
Wide Applicability ◽  
Internal Structures ◽  
Cultural Heritage Objects

Recently, we proposed stochastic point-based rendering, which enables precise and interactive-speed transparent rendering of large-scale laser-scanned point clouds. This transparent visualization method does not suffer from rendering artifact and realizes correct depth feel in the created 3D image.In this paper, we apply the method to several kinds of large-scale laser-scanned point clouds of cultural heritage objects and prove its wide applicability.In addition, we prove better image quality is realized by properly eliminating points to realize better distributional uniformity of points. Here, the distributional uniformity means uniformity of inter-point distances between nearest-neighbor points.We also demonstrate that highlighting feature regions, especially edges, in the transparent visualization helps us understand 3D internal structures of complex laser-scanned objects. The feature regions are highlighted by properly increasing local opacity of the regions.

Design of a quadrotor flight test stand for system identification

2015 ◽  
Vol 119 (1214) ◽  
pp. 501-521 ◽  
Author(s):  
M. M. Beharie ◽  
J. O. Pedro ◽  
L. Dala
Keyword(s):  
Mathematical Model ◽  
Power Plant ◽  
Flight Test ◽  
Test Stand ◽  
Bldc Motor ◽  
Design Development ◽  
Unknown Parameters ◽  
Box Structure ◽  
Alternate Forms ◽  
Mission Profile

AbstractThis paper presents the design, development and construction of a flight test stand for a quadrotor UAV. As opposed to alternate forms of UAV, the power plant in the case of the quadrotor serves a dual purpose of control and propulsion. Since control and propulsion are coupled, the power plant (BLDC motor coupled with propeller) was studied in detail using a black box structure. Extractions of motor parameters in previous studies used traditional BLDC motor equations and propeller theory however the accuracy achievable and confidence in the extracted parameters remained questionable. The developed data acquisition process served to satisfy this need by the construction of a test bench that allows for the extraction of the unknown parameters instilling confidence in the modelling process. The established relationships are then used as inputs into a developed six degree of freedom Euler based mathematical model. A mission profile was constructed with distinct phases of which the mathematical model was used to simulate. Each phase in the mission profile excited different modes of the quadrotor dynamics creating an ideal simulation environment in which changes can be implemented and studied.

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