Nuevas tecnologías en levantamientos aplicadas a la arqueología y la restauración

En las intervenciones arqueológicas la necesidad de dar cuenta de un modo científico del estado real de los yacimientos es una labor esencial. Para este cometido es necesario documentar gráficamente la geometría de los restos arqueológicos y su relación con el entorno de la manera más fidedigna posible. En los últimos años se ha dado un gran salto en la calidad y cantidad de la información geométrica que se puede obtener. Estas posibilidades en alza han estimulado la exigencia cada vez mayor de la rigurosidad en los levantamientos. Como muestra de las posibilidades de actuación aplicando tecnologías innovadoras se presenta este trabajo consistente en el levantamiento y modelizado de la muralla y barbacana descubierta en pleno centro de la ciudad de Sevilla con motivo de las obras del nuevo tren metropolitano. La singularidad del caso radica en que se trata de unos restos que serán extraídos de su ubicación actual para ser repuestos nuevamente una vez terminadas las obras de la estación de metro que se ubicará justo en esa localización pero a una cota inferior. En la actualidad no se ha tomado la decisión política sobre la posibilidad de ser nuevamente sepultados para permitir recuperar la configuración previa de la calle donde se descubrieron, o mantenerlos expuestos con la consecuente eliminación del tráfico de vehículos en la calle. De optarse por la primera opción correspondería al resultado de nuestro trabajo la responsabilidad de erigirse como referente virtual de unos restos arqueológicos inaccesibles. Con ocasión del trabajo se tendrá oportunidad de contrastar los resultados de la aplicación de técnicas de levantamiento mediante estación total láser, fotogrametría digital no métrica y escaneado láser tridimensionalIn archaeology, the necessity of scientifically stating the real condition of deposits is an essential work. For this task it is necessary to graphically document the geometry of the archaeological rests and their relationship with the environment in as accurate a way as possible. Over the last few years, great advances have been made in the quality and amount of the geometric information that can be obtained. These new possibilities incur difficulties regarding the required vigorous measurement and analysis of the data, however much improved results can be obtained. As an example of the performance possibilities, applying innovating technologies, we present this work consisting on the survey and modelling of the wall and barbican, discovered in the city of Seville, during the works of the new metropolitan train. The singularity of the case is that the wall will be extracted from its present location to be replaced back again once works of the tube station that will be located just in that location but to an inferior level finishes. At present the political decision between, being buried to allow the recovering of the previous configuration of the street, where they were discovered, or to be left exposed with the consequent elimination of the traffic of vehicles in the street, has not been taken yet. If the decision taken is the first option, our work would have the responsibility of being the virtual reference of an inaccessible archaeological rest. As a result of this work, we will have opportunity to check the results of the application of these techniques of survey by laser total station, non-metric digital photogrammetry and three-dimensional laser scannin

Determining image distortion and PBS (point of best symmetry) in digital images using straight line matrices

[EN] It is impossible to take accurate measurements in photogrammetry without first removing the distortion in images. This paper presents a methodology for correcting radial and tangential distortion and for determining the PBS (Point of Best Symmetry) without knowledge of the interior orientation parameters (IOPs). An analytical plumb-line calibration method is used, measuring only the coordinates of points on straight lines, regardless of the position and direction of these lines within the image. Points belonging to multiple lines can also be used since the effects on their X and Y coordinates are calculated independently. The results obtained on an image of a common scene, taken with a handheld non-metric camera, show a high degree of accuracy even with a minimum number of observables. And its application on a calibrated grid for engineering purposes with a semi-metric camera, results optimal even using a single image. (C) 2016 Elsevier Ltd. All rights reserved.The authors wish to thank CITES Espana and Direccion General de Bienes Culturales y Ensenanzas Artisticas, de la Consejeria de Educacion, Cultura y Universidades de la Comunidad Autonoma de la Region de Murcia, Museo Nacional de Arqueologia Subacuatica. Financial support is gratefully acknowledged from Spanish "I + D + I MINECO" projects CTQ2011-28079-CO3-01 and 02 and CTQ2014-53736-C3-1-P supported by ERDEF funds. The authors also wish to thank Mr. Manuel Planes and Dr. Jose Luis Moya, technical supervisors of the Electron Microscopy Service of the Universitat Politecnica de Valencia.Herráez Boquera, J.; Denia Ríos, JL.; Navarro Esteve, PJ.; Rodríguez Pereña, J.; Martín Sánchez, MT. (2016). Determining image distortion and PBS (point of best symmetry) in digital images using straight line matrices. Measurement. 91:641-650. https://doi.org/10.1016/j.measurement.2016.05.051S6416509

APPLICATIONS OF THREE-DIMENSIONAL SCANNING TECHNOLOGY FOR THE COORDINATION OF HISTORICAL MONUMENTS OF NATIONAL INSTITUTE OF ARCHAEOLOGY AND HISTORY (INAH) IN MEXICO CITY. (2009 AND 2010)

[EN] The National Institute of Archaeology and History manages the documentation and preservation of the patrimony of Mexico, a country with an area of ??1.959.000 square kilometers, which is almost four times the size of Spain. To attend on all this patrimony, INAH has several departments. The National Coordination of Historical Monuments manages the monuments and architecture built from the colonial era. Inside the Coordination, the Technical Support Division manages the teams and the tools necessary for the survey[ES] El Instituto Nacional de Arqueología e Historia gestiona la documentación y conservación del patrimonio de México un país con una extensión de 1.959000 kilómetros cuadrados, que casi cuadriplica la extensión de España. Para atender todo este Patrimonio el INAH cuenta con diversos departamentos. La Coordinación Nacional de Monumentos Históricos gestiona los monumentos y arquitecturas construidos a partir de la época virreinal. Dentro de la Coordinación, la Dirección de Apoyo Técnico gestiona los equipos e instrumentos necesarios para el levantamiento.Navarro Esteve, P.; Herráez Boquera, J.; Mora Flores, Á.; Barros E Costa, H.; Denia Ríos, JL. (2011). APLICACIONES DE LA TECNOLOGÍA DE DIGITALIZACIÓN TRIDIMENSIONAL POR LA COORDINACIÓN DE MONUMENTOS HISTÓRICOS DEL INSTITUTO NACIONAL DE ARQUEOLOGÍA E HISTORIA (INAH) EN MÉXICO DF. (2009 Y 2010). EGA. Revista de Expresión Gráfica Arquitectónica. 16(17). doi:10.4995/ega.2011.882SWORD4253161

Restoration of paintings on domes with non-developable geometry (Los Santos Juanes Church in Valencia)

[EN] The restoration of paintings on elements in cultural heritage buildings (fundamentally, churches) involves two structural problems: capturing the geometry of the construction element and its development. In many cases, the geometries are regular (e.g., cylinders, spheres, elliptical domes). However, there are cases in which the elements cannot be adapted to any known geometry, much less one that can be mathematically developed. The development of surfaces becomes essential for the restoration of paintings over "flat elements" (over which work is performed on the ground) that are subsequently transferred to the real surface (ceilings). The mathematical transformations that allow regular geometries to be developed are widely known (cartographic projections). However, when the geometry is irregular, there is no development. This study presents a new methodology based on differential rectification and its application for the development of oculi in the Los Santos Juanes Church (Valencia), whose geometry is completely irregular both in shape and as a result of construction defects (and damage caused by fire). The present study focuses on the restoration of paintings damaged by fire.Navarro Esteve, PJ.; Yudici Oliver, SA.; Herráez Boquera, J.; Denia Rios, JL.; Martín Sánchez, MT.; Rodríguez Pereña, J. (2018). Restoration of paintings on domes with non-developable geometry (Los Santos Juanes Church in Valencia). International Journal of Architectural Heritage. 12(2):169-177. https://doi.org/10.1080/15583058.2017.1356946S16917712

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

[EN] 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)Herráez Boquera, J.; Denia Rios, JL.; Priego De Los Santos, E.; Navarro Esteve, PJ.; Martín Sánchez, MT.; Rodríguez Pereña, J. (2021). Cultural Heritage Restoration of a Hemispherical Vault by 3D Modelling and Projection of Video Images with Unknown Parameters and from Unknown Locations. Applied Sciences. 11(12):1-12. https://doi.org/10.3390/app11125323112111

Epipolar image rectification through geometric algorithms with unknown parameters

Herráez Boquera, J., Denia Rios, J.L., Navarro Esteve, P.J., Rodríguez Pereña, J., Martín Sánchez M.T."Epipolar image rectification through geometric algorithms with unknown parameters". JJ. Electron. Imaging. 22(4), 043021 (Dec 02, 2013). © (2013) Society of Photo-Optical Instrumentation Engineers. One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. http://dx.doi.org/10.1117/1.JEI.22.4.043021Image processing in photogrammetry is commonly used for scene reconstruction. Although two-dimensional applications can be solved using isolated images, reconstruction of three-dimensional scenes usually requires the use of multiple images simultaneously. Epipolar image rectification is a common technique for this purpose. It typically requires internal orientation parameters and, therefore, knowledge of camera calibration and relative orientation parameters between images. A reparameterization of the fundamental matrix through a completely geometric algorithm of seven parameters that enables the epipolar image rectification of a photogrammetric stereo pair without introducing any orientation parameters and without premarking ground control points is presented. The algorithm enables the generation of different stereoscopic models with a single photogrammetric pair from unknown cameras, scanned from a book, or frames from video sequences. Stereoscopic models with no parallaxes have been obtained with a standard deviation of <0.5 pixels. (C) 2013 SPIE and IS&THerráez Boquera, J.; Denia Rios, JL.; Navarro Esteve, PJ.; Rodríguez Pereña, J.; Martín Sánchez, MT. (2013). Epipolar image rectification through geometric algorithms with unknown parameters. Journal of Electronic Imaging. 22(4). doi:10.1117/1.JEI.22.4.04302104302122

Three-dimensional image orientation through only one rotation applied to image processing in engineering

Photogrammetry is a science with many fields of application in civil engineering where image processing is used for different purposes. In most cases, the use of multiple images simultaneously for the reconstruction of 3D scenes is commonly used. However, the use of isolated images is becoming more and more frequent, for which it is necessary to calculate the orientation of the image with respect to the object space (exterior orientation), which is usually made through three rotations through known points in the object space (Euler angles). We describe the resolution of this problem by means of a single rotation through the vanishing line of the image space and completely external to the object, to be more precise, without any contact with it. The results obtained appear to be optimal, and the procedure is simple and of great utility, since no points over the object are required, which is very useful in situations where access is difficult.Herráez Boquera, J. (2008). Three-dimensional image orientation through only one rotation applied to image processing in engineering. Applied Optics. 47(35):6631-6637. doi:10.1364/AO.47.006631S66316637473

Automation of thermographic 3D modelling through image fusion and image matching techniques

Infrared thermography has proved to be an adequate technique for building inspection, as it can be used to determine energy efficiency and also to detect defects in construction. Geometry and spatial relationships are also very important in building inspection because they make location of thermal defects and measurement of affected surfaces possible. A procedure to fuse automatically generated infrared mosaics and visible images to combine geometric information with thermal data in the same image is described in this paper. Fused images are then used for the automatic generation of a thermographic 3D model of the building through image matching, where apart from having thermographic information available, geometric measurements can be performed. The proposed methodology is suitable for building inspection, where working space and time are usually limited so a reduction on the number and size of instruments is appreciated. Furthermore, automation of the process diminishes the error in results by avoiding operator's influence.The authors would like to give thanks to Conselleria de Economia e Industria (Xunta de Galicia), Ministerio de Economia y Competitividad and CDTI (Gobierno de Espana) for the financial support given; human resources programs (FPU AP2009-1144) and projects (INCITE 10TMT 011CT, INCITE 10REM033E, IDI-20101770). All the programs are cofinanced by the Fondo Europeo para el Desarrollo Regional (FEDER).Lagüela, S.; Armesto, J.; Arias, P.; Herráez Boquera, J. (2012). Automation of thermographic 3D modelling through image fusion and image matching techniques. Automation in Construction. 27:24-31. doi:10.1016/j.autcon.2012.05.011S24312

High performance grid for the metric calibration of thermographic cameras

The metric calibration of thermographic cameras would make possible the acquisition of geometric data if the principles of photogrammetry are followed. Both the distortion effects introduced in the images by the lens and the perspective effect can be corrected if the calibration parameters are known. This paper presents a calibration grid that allows the automatic metric calibration of thermographic cameras. This calibration grid is made of light and easy-to-find materials to guarantee its portability and handling. The calibration parameters obtained with the presented calibration grid are verified and compared with those obtained with a temperature-based calibration grid through the evaluation of the accuracy and repeatability in the modelling of a standard artefact previously certified. © 2012 IOP Publishing Ltd.The authors would like to thank Conselleria de Economia e Industria (Xunta de Galicia) and Ministerio de Ciencia e Innovacion (Gobierno de Espana) for the financial support given: human resource programmes (IPP055-EXP44, FPU AP2009-1144) and projects (INCITE09 304 262 PR, INCITE 10TMT 011CT and BIA2009-08012). All programmes are cofinanced by the Fondo Europeo para el Desarrollo Regional (FEDER).Laguela, S.; Gónzalez-Jorge, H.; Armesto, J.; Herráez Boquera, J. (2012). High performance grid for the metric calibration of thermographic cameras. Measurement Science and Technology. 23(1):1-9. doi:10.1088/0957-0233/23/1/015402S1923

Technical study for restoration of mural paintings through the transfer of a photographic image to the vault of a church

[EN] This study, which is part of the project for the restoration of the pictorial set that Antonio Palomino painted on the vault of the central nave of the Church of the Santos Juanes in the city of Valencia (Spain), describes the complete geometric study for the digital restitution of these paintings, after their partial destruction in a fire caused during the Spanish Civil War.Two analogic black and white photographs taken before the fire (1920), will be the key to the reha-bilitation of these valuable paintings. 3D modelling with laser scanning systems of the vault provides the geometry with precision and a high level of detail of the surface on which the paintings were carried out, in addition to the structural elements that make up the architecture of the temple.The solution proposed approaches a new methodology for the digital reconstruction of the rectified image and its subsequent georeferencing, as well as the entire environment to determine the correct location of the artistic work. Today, digital or virtual restoration is considered a very useful technique for the restoration of old photographs, but it is also an excellent opportunity to develop possible solutions in restoration of paintings and frescoes.This paper describes the initial process of transferring the paintings of this Spanish artist, from a photographic image of the original frescoes (2D) to the irregular surface and volume (3D) of the current cover of this Valencian Royal Parish, through a restoration of the mural set.(c) 2022 Consiglio Nazionale delle Ricerche (CNR). Published by Elsevier Masson SAS. All rights reserved.Priego De Los Santos, E.; Herráez Boquera, J.; Denia Rios, JL.; Navarro Esteve, PJ. (2022). Technical study for restoration of mural paintings through the transfer of a photographic image to the vault of a church. Journal of Cultural Heritage. 58:112-121. https://doi.org/10.1016/j.culher.2022.09.0231121215