Juan Carlos Torres

University of Granada | UGR · Virtual Reality Laboratory

Monocular Simultaneous Localization and Mapping (SLAM), Visual Odometry (VO), and Structure from Motion (SFM) are techniques that have emerged recently to address the problem of reconstructing objects or environments using monocular cameras. Monocular pure visual techniques have become attractive solutions for 3D reconstruction tasks due to their a...

Generating chemical element maps of paintings from X-ray fluorescence (XRF) data is a very valuable tool for the scientific community of conservators and art historians. Hand-held XRF scanners are cheap and easily portable but their use provides scans with a few data, so additional analytical tools are needed to obtain reliable chemical element map...

Monocular Simultaneous Landing and Mapping (SLAM), Visual Odometry (VO), and Structure from Motion (SFM) are techniques that have emerged recently to address the problem of reconstructing objects or environments using monocular cameras. Monocular pure visual techniques have become attractive solutions for 3D reconstruction tasks due to their afford...

Pure monocular 3D reconstruction is a complex problem that has attracted the research community’s interest due to the affordability and availability of RGB sensors. SLAM, VO, and SFM are disciplines formulated to solve the 3D reconstruction problem and estimate the camera’s ego-motion; so, many methods have been proposed. However, most of these met...

Pure monocular 3D reconstruction is an ill-posed problem that has attracted the research community's interest due to the affordability and availability of RGB sensors. SLAM, VO, and SFM are disciplines formulated to solve the 3D reconstruction problem and estimate the camera’s ego-motion, so many methods have been proposed. However, most of these m...

The different non-invasive techniques that have been developed for the study of works of art in Cultural Heritage have become an indispensable tool for researchers and practitioners. In particular, the creation of images showing the spatial distribution of chemical elements and pigments, called maps, helps give a better understanding of the artwork...

Virtual reality (VR) has been brought closer to the general public over the past decade as it has become increasingly available for desktop and mobile platforms. As a result, consumer-grade VR may redefine how people learn by creating an engaging “hands-on” training experience. Today, VR applications leverage rich interactivity in a virtual environ...

Cost surfaces are a useful tool for solving many spatial analysis problems. However, GIS tools are limited when used to compute cost surfaces. This is primarily because they can only deal with isotropic frictions or, at best, they use a very limited definition of anisotropic friction that only considers local information, thereby generating unnatur...

Background Pregnancy is a period of particular vulnerability to experience intimate partner violence against women (IPVAW). eHealth strategies have been implemented to identify women exposed to IPVAW and to combat the abuse and empower them, but there is a lack of evidence on the use of these strategies among pregnant women. This work aims to ident...

This paper introduces a precise and easy to use method for defining the microstructure of heterogeneous solids. This method is based on the concept of Heterogeneous Composite Bézier Hyperpatch, and allows to accurately represent the primary material proportions, as well as the size and shape of the material phases. The solid microstructure is model...

This paper introduces a flexible and easy to use method for designing complex composite heterogeneous materials. These materials feature two distinct phases called core and matrix that remain separate and distinct. Moreover, composite materials have an internal microarchitecture that have to be precisely modeled. All the microarchitecture examples...

The study objective was to determine dental parameters that characterize human bitemarks and dentitions for biter identification using semi-automatized technology. Sixty-five dental casts and eighteen bitemark photographs were used. Casts were scanned by a 3D laser scanner to generate comparison overlays, and bitemarks were digitally photographed f...

We propose a new architecture for 3D information systems that takes advantage of the inherent parallelism of the GPUs. This new solution structures information as thematic layers, allowing a level of detail independent of the resolution of the meshes. Previous proposals of layer based systems present issues, both in terms of performance and storage...

The design of the industrial facilities distribution is one of the most important decisions to be made, as it will condition the operation thereof. The concept of industrial installation as it is known today has evolved to the point that it integrates automation and information systems. Indeed, such evolution has given rise to the so-called intelli...

CHISel is a cultural heritage information system that supports the extensive organization, tracking, and implementation of data on 3D computer generated models of archaeological artefacts and site. We conducted a detailed user test of CHISel, to assess the usability of the complex and numerous system features, in order to assess the efficiency, use...

In this usability evaluation of the Fountain of the Lions software application aimed to be used by museum visitors, the software is analysed using three established usability research methods: personas, a cognitive walkthrough (task analysis) with three participants, and an individual heuristic evaluation. Areas in which the software succeeds and a...

The aim of this study was to develop new software to describe tooth marks from photographs of human bites. Using these images, BitePrint software approximates each tooth mark as an ellipse and the dental arch as a semi-circle. The expert marks the mesiodistal length and the bucco-lingual width of each tooth mark and the software automatically fits...

Three-dimensional terrain reconstruction from 2D aerial images is a problem of utmost importance due its wide level of applications. It is relevant in the context of intelligent systems for disaster managements (for example to analyze a flooded area), soil analysis, earthquake crisis, civil engineering, urban planning, surveillance and defense rese...

Many real objects are heterogeneous. They are composed of diverse materials, which are present in varying proportions. Materials inside the solid do not have to be uniformly distributed. So, methods capable of accurately model not only the boundary of the solid, but also the distribution of material in every single point of its interior, are needed...

Exploratory data analysis constitutes a challenge for scientists and analysts of multiples disciplines. Most current methods and tools do not allow for analyzing effectively several variables simultaneously. This paper addresses the problem of visual analysis of temporal sequences of multiple variables using multiparameter visualization techniques...

En la actualidad existe un amplio consenso sobre el uso de las técnicas de realidad virtual (RV) para el tratamiento de diferentes trastornos como fobias específicas, trastornos de la conducta alimentaria o adicciones. Presentamos aquí los resultados de ANALGESIA, un software de RV para inducir estados de bienestar y relajación. Consiste en un conj...

Abstract Formal models can be useful in computer graphics as a conceptual framework supporting representation systems. This allows to formally derive properties and algorithms and proof their correctness and validity. This paper describes a formal model based on a geometric algebra. This algebra has been used to obtain specific representation syste...

The information about cultural heritage artifacts that archeologists must manage is usually very heterogenous, and, due to its spatial nature, cannot be easily represented using conventional data management frameworks. The strong spatial dependence of this data suggests that the information should be linked to a 3D model of the artifact. This artic...

Conventional information systems are frequently used to document Cultural Heritage sites. These systems are adequate for some specific purposes as they can store and retrieve a large amount of heterogeneous documents. Nevertheless, this is not enough for research and conservation purposes; researchers need to be able to find out relations between d...

En arqueología, y en patrimonio histórico en general, la información gestionada es de muy diversa índole, incluyendo desde, medidas, anotaciones, croquis, y planos, hasta fotografías o modelos 3D, pasando por resultados de análisis. Además de esta heterogeneidad, estos datos, tienen una característica esencial: están asociados a localizaciones conc...

Body sensor networks (BSNs) enable the pervasive, long-term, and real-time monitoring in any environment and without restriction of activity. Security and privacy are extremely critical issues of BSNs, as sensitive information is transmitted through ...

The exploration of large GIS models containing spatio-temporal information is a challenge. In this paper we propose the integration of scientific visualization (ScVis) techniques into geographic information systems (GIS) as an alternative for the visual analysis of data. Providing GIS with such tools improves the analysis and understanding of datas...

The exploration of large GIS models containing spatio-temporal information is a challenge. In this paper we propose the integration of scientific visualization (ScVis) techniques into geographic information systems (GIS) as an alternative for the visual analysis of data. Providing GIS with such tools improves the analysis and understanding of datas...

Managing information related to cultural heritage sites is an important task and much work has been devoted to developing special purpose document management systems. These systems are able to store and retrieve large amounts of documents; however, while this is adequate for some purposes, it is not sufficient for research and conservation work. Re...

Integral field spectroscopy (IFS) is a technique that is widely used in astronomy. It gives simultaneously the spectra of each spatial sampling element of a given field, generating a large amount of information that is also known as data cube. Visualizing and exploring these data cubes in a flexible and an intuitive way is a challenge. Although the...

Computational methods to generate three dimensional models from photographies have received increasing attention in the last years. Nowadays, although they are not a substitutive to laser scanners, they are a viable alternative in cases were using a laser scanner is not possible. These methods are also attractive because they do not need the acquis...

Integral field spectroscopy (IFS) is a technique that is widely used by astrophysics. It allows the whole electromagnetic spectrum for each pixel of a telescope image to be captured, generating a large amount of information. Visualizing and exploring this information in a flexible and an intuitive way is a challenge. This paper presents an interact...

Geographic information systems (GIS) allow us to manage information related to a territory in an efficient and flexible way. Management of information concerning cultural heritage presents a set of requirements which are similar to those. In processes such as documentation, restoration and preservation it is necessary to locate a wealth of informat...

que se plantea en Nivel 13. En esta lección se aborda la creación y utilización de mundos virtuales. Es decir, el proceso de crear un escenario que sea una réplica virtual de un entorno real y la presentación de este escenario de forma que parezca real. Esto nos plantea dos caminos inversos: crear representaciones computacionales precisas de la rea...

Work on archaeological sites or cultural heritage artefacts usually generates a huge amount of heterogeneous information. The strong spatial structure of data suggests that this information should be linked to a threedimensional model of the artefact. This paper presents a new approach to the representation and management of information in the Cult...

Considerable efforts have been done to produce realistic results when simulating interaction with elastic materials. Many applications such as surgery planning, medical training, or virtual sculpting would benefit from a plausible simulation scenario. However, even though many works have proposed very satisfactory results, realistic simulation of d...

Las superficies de coste son una solución precalculada del problema de camino mínimo en mapas raster. Normalmente los sistemas GIS utilizan un mapa para almacenar los costes unitarios, que son constantes para cada celda, lo que implica resolver un problema isotrópico. No obstante, los problemas reales no suelen ser isotrópicos. En este trabajo se p...

Within the limits of current technology, many applications of a virtual environment will trade-off accuracy for speed. This is not an acceptable compromise in a medical training application where both are essential. Efficient algorithms must therefore be developed. The purpose of this project is the development and validation of a novel physics-bas...

In the initial stages of a design process, information is intrinsically imprecise due to the vagueness of designers’ ideas and their lack of initial information. The geometric modeling capabilities provided by current CAD systems are unable to manipulate an initial rough model or objects the geometry of which is incomplete. Our approach aims to clo...

En este trabajo se aborda el problema de la detección de inclusión y el cálculo de distancia a la superficie en modelos poligonales de varios cientos de miles de polígonos. Este problema es especialmente importante en el contexto de la interacción con dispositivos hápticos, presente en aplicaciones de realidad vütual tales como sistemas de entrenam...

In the initial stages of a design process, information is intrinsically imprecise due to the vagueness of designers' ideas and their lack of initial information. The geometric modeling capabilities provided by current CAD systems are unable to manipulate an initial rough model or objects the geometry of which is incomplete. Our approach aims to clo...

En el proceso de restauración y conservación del patrimonio histórico se hace necesaria la utilización de todas las técnicas disponibles que puedan aportar un adecuado conocimiento del proceso que se realice. En este artículo presentamos los trabajos realizados mediante el uso de escáner láser 3D para el registrado y documentación del estado de la...

Many researchers have dealt during last decade about digitizing and reconstructing hand made pottery elements from fragments retrieved in the archaeological excavations. Some studies have demonstrated the huge variability in results from manual processes, which usually leads into a wrong typological classification of the profile. Moreover, after or...

3D digitalization has become a common tool in archaeology. However, the post processing of the data produced by the scanners is still quite complex, and the computer models generated are given very few practical applications. In this paper, we analyse the key steps involved in the processing of the point clouds. We also review some of the more usu...

One of the most important problems nowadays in virtual archaeology is the fact that scanning real models produces huge amount of polygons, and these polygons must be rendered and displayed in a interactively way, trying to minimize the hardware requirements. In a global world, internet has become the most important way of knowledge, and archaeology...

Large-range laser scanners provide a huge number of points that are not so easy to handle with laptops and current commercial software. Each laser capture can have several million points, and usually it is needed more than one to retrieve the complete surface. These digitalization devices are used for scanning large areas like buildings, walls or g...

Volume data are usually represented as a uniform structured grid. Nevertheless, this representation imposes large memory requirements when large volumes are stored.Hierarchical representations can be used to reduce either memory requirements or rendering time. They have been used as index to the cell grid, but this increases memory requirements, as...

In this paper we present a new data structure: the BP-Octree (Bounding-planes Octree). The BP-Octree is based on a spatial decomposition of the model using an octree, and offers a very tight hierarchy of convex bounding volumes which leads to simplified models. It is done by assigning to each node of the tree a set of planes that, intersected one a...

Three dimensional datasets representing scalar fields are frequently rendered using isosurfaces. For datasets arranged as a cubic lattice, the marching cubes algorithm is the most used isosurface extraction method. However, the marching cubes algorithm produces some ambiguities which have been solved using different approaches that normally imply a...

En este artículo presentamos una introducción al problema de la generación de modelos 3D a partir de datos obtenidos mediante escáner láser, analizando brevemente los trabajos más significativos dentro de este campo. A continuación proponemos un sistema cuya finalidad es la semiautomatización del proceso completo. Para ello, el sistema se apoya en...

Validation studies of the new DentalPrint software were carried out with experimental bite marks in pigskin. The bite marks were digitally photographed according to the ABFO guidelines for evidence collection. Dental casts used in the experiment were scanned in 3D and 2D, and comparison overlays were generated using DentalPrint and Adobe Photoshop...

En este trabajo nos proponemos estudiar el modelado y visualización de modelos raster 3D en un sistema GIS (Geographic Information System) permitiendo la vista tridimensional y el análisis de la capa atmosférica terrestre en unavariedad significativa de parámetros, ahondando en las capacidades que otorga un GIS GPL (como GRASS) y en los distintos fo...

En el presente trabajo se presenta una nueva estructura de datos que permite representar un solido mediante una jerarquía de planos espacialmente indexados. Se hace uso de un árbol para realizar la jerarquizacion tridimensionalmente indexada. Los planos que correponden a los nodos de dicho nivel forman una envolvente convexa del sólido en el volume...