Filters

2006 - 20098
Reset filters

Settings

Author: Callieri, Marco × Has files: true × Start date: 2006 × End date: 2009 ×

Search Results

Now showing 1 - 8 of 8
  • Thumbnail Image
    Item
    Mapping highly detailed color information on extremely dense 3D models: the case of David s restoration
    (The Eurographics Association, 2007) Dellepiane, Matteo; Callieri, Marco; Ponchio, Federico; Scopigno, Roberto; David B. Arnold and Andrej Ferko
    The support of advanced Information Technology (IT) to preservation, restoration and documentation of Cultural Heritage is becoming a very important goal for the research community. Michelangelo's David was one of the first applications of 3D scanning technology on a highly popular work of art. The subsequent restoration campaign, started in 2002 and concluded in 2004, was also a milestone for the adoption of modern scientific analysis procedures and IT tools in the framework of a restoration process. One of the focuses in this restoration was also methodological, i.e. to plan and adopt innovative ways to document the restoration process. In this paper we present the results of an integration of different restoration data (2D and 3D datasets) which has been concluded recently. The recent evolution of HW and SW graphics technologies gave us the possibility to interactively visualize an extremely dense 3D model which incorporates the color information provided by two professional photographic campaigns, made before and after the restoration. Moreover, we present the results concerning the mapping, in this case on the 2D media, of the reliefs produced by restorers to assess and document the status of the marble surface before the restoration took place. This result could lead to new and fascinating applications of computer graphics for preservation, restoration and documentation of Cultural Heritage.
  • No Thumbnail Available
    Item
    Multiple Uses of 3D Scanning for the Valorization of an Artistic Site: the Case of Luni
    (The Eurographics Association, 2008) Dellepiane, Matteo; Callieri, Marco; Paribeni, Emanuela; Sorge, Elena; Sulfaro, Nino; Marianelli, Veronica; Scopigno, Roberto; Vittorio Scarano and Rosario De Chiara and Ugo Erra
    The heritage site of Luni is a very interesting location, which tells the story of an ancient roman colony, and of an area where different cultures left their heritage. In particular, the remains of the pediments of an ancient temple represent a very interesting case and an open field of study for art historians. The scanning of a group of statue belonging to the pediments showed that the produced 3D models could be used in several ways, not only for archival and presentation purposes but also to provide interactive support for the work of the restorers and the scholars. In particular, the use of 3D models to propose and validate hypothesis about the original position of the fragments in the context of the fronton could be an alternative solution to the direct manipulation of them. Moreover, the analysis of the original color of the statues, and the representation different hypothesis about the ancient appearance can be produced through the interactive editing of the 3D models of the statues. In this paper we present the scanning campaign which resulted in the acquisition of five statues,the preliminary results of some of the uses of the models produced with acquired data, and a brief description of other possible future applications of them. This shows how 3D scanning can be considered by now a mature technology for the support of restoration and preservation of Cultural Heritage.
  • Thumbnail Image
    Item
    High Quality PTM Acquisition: Reflection Transformation Imaging for Large Objects
    (The Eurographics Association, 2006) Dellepiane, Matteo; Corsini, Massimiliano; Callieri, Marco; Scopigno, Roberto; Marinos Ioannides and David Arnold and Franco Niccolucci and Katerina Mania
    Reflection Transformation Imaging has proved to be a powerful method to acquire and represent the 3D reflectance properties of an object, displaying them as a 2D image. Recently, Polynomial Texture Maps (PTM), which are relightable images created from a set of photos of the object taken under several different lighting conditions, have been used in Cultural Heritage field to document and virtually inspect several sets of small objects, such as cuneiform tablets and coins. In this paper we explore the possibility of producing high quality PTM of medium or large size objects. The aim is to analyze the acquisition pipeline, resolving all the issues related to the size of the object, and the conditions of acquisition. We will discuss issues regarding acquisition planning and data gathering. We also present a new tool to interactively browse high resolution PTMs. Moreover, we perform some quality assessment considerations, in order to study the degradation of quality of the PTMs respect to the number and position of lights used to acquire the PTM. The results of our acquisition system are presented with some examples of PTMs of large artifacts like a sarcophagus of 2.4 × 1 m size. PTM can be a good alternative to 3D scanning for capturing and representing certain class of objects, like bas-relieves, having lower costs in terms of acquisition equipment and data processing time.
  • Thumbnail Image
    Item
    Stereo Light Probe
    (The Eurographics Association and Blackwell Publishing Ltd, 2008) Corsini, Massimiliano; Callieri, Marco; Cignoni, Paolo
    In this paper we present a practical, simple and robust method to acquire the spatially-varying illumination of a real-world scene. The basic idea of the proposed method is to acquire the radiance distribution of the scene using high-dynamic range images of two reflective balls. The use of two light probes instead of a single one allows to estimate, not only the direction and intensity of the light sources, but also the actual position in space of the light sources. To robustly achieve this goal we first rectify the two input spherical images, then, using a region-based stereo matching algorithm, we establish correspondences and compute the position of each light. The radiance distribution so obtained can be used for augmented reality applications, photo-realistic rendering and accurate reflectance properties estimation. The accuracy and the effectiveness of the method have been tested by measuring the computed light position and rendering synthetic version of a real object in the same scene. The comparison with standard method that uses a simple spherical lighting environment is also shown.
  • Thumbnail Image
    Item
    Pushing Time-of-Flight Scanners to the Limit
    (The Eurographics Association, 2009) Callieri, Marco; Cignoni, Paolo; Dellepiane, Matteo; Scopigno, Roberto; Kurt Debattista and Cinzia Perlingieri and Denis Pitzalis and Sandro Spina
    The paper describes a pipeline for 3D scanning acquisition and processing that allow to exploit the utmost precision and quality out of ToF scanners. The proposed approach capitalize on the knowledge of the distribution of the noise to apply sophisticated fairing techniques for cleaning up the data. Leveraging on the very dense sampling of this kind of scanners we show that is possible to attain high accuracy. We present a practical application of the proposed approach for the scanning of a large (5mt) statue with millimetric precision.
  • Thumbnail Image
    Item
    Using 3D Scanning to Analyze a Proposal for the Attribution of a Bronze Horse to Leonardo da Vinci
    (The Eurographics Association, 2007) Dellepiane, Matteo; Callieri, Marco; Fondersmith, Mark; Cignoni, Paolo; Scopigno, Roberto; D. Arnold and F. Niccolucci and A. Chalmers
    In this paper we present how technologies developed in the context of 3D graphics (3D scanning and image-to- 3D-model mapping) have been used to evaluate in a metrically objective way the plausibility of an attribution hypothesis of a Renaissance artifact. The artifact considered is a small bronze horse (Archeological Museum, Florence, Italy), which was discovered to be very similar to a silverpoint drawing by Leonardo (Leonardo drawing #358, Windsor Royal Library, UK), thus originating an attribution hypothesis. A highly accurate digital replica of this small bronze statue was reconstructed by means of triangulation-based 3D scanning technology. Using image-to-3D-model mapping techniques the Leonardo s drawing depicting a very similar horse has been aligned to the digital 3D model, reconstructing in a virtual manner the ideal vantage points which could have been used to sketch the drawings of the horse (in the hypothesis that Leonardo had drawn it by directly looking at the bronze). The same approach has been also tried with other Leonardo s drawings depicting a similar subject, but none of those was sufficiently compatible in shape with the bronze horse to allow convergence of the image-to-3D mapping process. The approach proposed allows us to give some visually objective evidences about the shape similarity issue, which was the origin of this attribution attempt. At the same time, a purely technical evaluation does not close the attribution issue. Further archival research and expertise will be needed to solve and assess the issue of this disputed hypothesis.
  • No Thumbnail Available
    Item
    MeshLab: an Open-Source Mesh Processing Tool
    (The Eurographics Association, 2008) Cignoni, Paolo; Callieri, Marco; Corsini, Massimiliano; Dellepiane, Matteo; Ganovelli, Fabio; Ranzuglia, Guido; Vittorio Scarano and Rosario De Chiara and Ugo Erra
    The paper presents MeshLab, an open source, extensible, mesh processing system that has been developed at the Visual Computing Lab of the ISTI-CNR with the helps of tens of students. We will describe the MeshLab architecture, its main features and design objectives discussing what strategies have been used to support its development. Various examples of the practical uses of MeshLab in research and professional frameworks are reported to show the various capabilities of the presented system.
  • Thumbnail Image
    Item
    Artifacts Removal for Color Projection on 3D Models using Flash Light
    (The Eurographics Association, 2009) Dellepiane, Matteo; Callieri, Marco; Corsini, Massimiliano; Cignoni, Paolo; Scopigno, Roberto; Kurt Debattista and Cinzia Perlingieri and Denis Pitzalis and Sandro Spina
    Abstract Lighting artifacts are one of the main issues in digital photography: complex light setups are needed to attenuate or remove them. Flash light is a very easy way to illuminate an object or an environment, but it is rarely considered in most of the Computer Graphics and Computer Vision applications. This is due to the big amount of artifacts introduced by this lighting, and to the difficulty in modeling its behavior. In this paper we present a simple method to use flash light in the context of color acquisition and mapping on 3D models. We propose a simple way to accurately estimate the flash position with respect to the camera, and we propose two automatic methods to detect and remove artifacts from a set of images which are registered to a 3D model. These methods are integrated in the context of a color mapping framework. The results show that it is possible to obtain high quality colored 3D models using flash light, which is the most simple illumination setup. This results are extremely important especially in the context of Cultural heritage, where the acquisition of color has often to be performed on site, without a specific lighting setup.