2007
Conference article
Open Access
Extending geometrical acoustics to highy detailed architectural environments
Tsingos N., Dachsbacher C., Lefebvre S., Dellepiane M.
Geometrical acoustics (GA) is a widely used approximation for simulating sound propagation in virtual 3D environments. However, GA is a high-frequency approximation and therefore very detailed models, containing features small compared to audible wavelengths, may fall outside its validity domain. Including finer geometrical details might actually degrade the quality of the simulation, as supported by a number of previous studies. Furthermore, the cost of running GA-based simulations significantly increases with the geometrical complexity. In this paper, we propose an extension to GA for highly detailed environments. In particular, we pre-compute a representation of the scattering behavior off complex geometry using finite element techniques. We then use this representation within classical GA frameworks, such as radiosity or ray-casting, to compute impulse responses and auralize the corresponding acoustical effects.Source: 19th International Congress on Acustics, Madrid, Spain, 2-7 Settembre 2007
Tsingos N., Dachsbacher C., Lefebvre S., Dellepiane M.
Geometrical acoustics (GA) is a widely used approximation for simulating sound propagation in virtual 3D environments. However, GA is a high-frequency approximation and therefore very detailed models, containing features small compared to audible wavelengths, may fall outside its validity domain. Including finer geometrical details might actually degrade the quality of the simulation, as supported by a number of previous studies. Furthermore, the cost of running GA-based simulations significantly increases with the geometrical complexity. In this paper, we propose an extension to GA for highly detailed environments. In particular, we pre-compute a representation of the scattering behavior off complex geometry using finite element techniques. We then use this representation within classical GA frameworks, such as radiosity or ray-casting, to compute impulse responses and auralize the corresponding acoustical effects.Source: 19th International Congress on Acustics, Madrid, Spain, 2-7 Settembre 2007
See at:
www.sea-acustica.es 
| CNR ExploRA
2007
Conference article
Restricted
Instant Sound Scattering
Tsingos N., Dachsbacher C., Lefevbre S., Dellepiane M.
Real-time sound rendering engines often render occlusion and early sound reflection effects using geometrical techniques such as ray or beam tracing. They can only achieve interactive rendering for environments of low local complexity resulting in crude effects which can degrade the sense of immersion. However, surface detail or complex dynamic geometry has a strong influence on sound propagation and the resulting auditory perception. This paper focuses on high-quality modeling of first-order sound scattering. Based on a surface-integral formulation and the Kirchhoff approximation, we propose an efficient evaluation of scattering effects, including both diffraction and reflection, that leverages programmable graphics hardware for dense sampling of complex surfaces. We evaluate possible surface simplification techniques and show that combined normal and displacement maps can be successfully used for audio scattering calculations. We present an auralization framework that can render scattering effects interactively thus providing a more compelling experience. We demonstrate that, while only considering first order phenomena, our approach can provide realistic results for a number of practical interactive applications. It can also process highly detailed models containing millions of unorganized triangles in minutes, generating high-quality scattering filters. Resulting simulations compare well with on-site recordings showing that the Kirchhoff approximation can be used for complex scattering problems.Source: Eurographics Symposium on Rendering, pp. 111–120, Grenoble, France, 25-27 Giugno 2007
DOI: 10.2312/egwr/egsr07/111-120
Metrics:
Tsingos N., Dachsbacher C., Lefevbre S., Dellepiane M.
Real-time sound rendering engines often render occlusion and early sound reflection effects using geometrical techniques such as ray or beam tracing. They can only achieve interactive rendering for environments of low local complexity resulting in crude effects which can degrade the sense of immersion. However, surface detail or complex dynamic geometry has a strong influence on sound propagation and the resulting auditory perception. This paper focuses on high-quality modeling of first-order sound scattering. Based on a surface-integral formulation and the Kirchhoff approximation, we propose an efficient evaluation of scattering effects, including both diffraction and reflection, that leverages programmable graphics hardware for dense sampling of complex surfaces. We evaluate possible surface simplification techniques and show that combined normal and displacement maps can be successfully used for audio scattering calculations. We present an auralization framework that can render scattering effects interactively thus providing a more compelling experience. We demonstrate that, while only considering first order phenomena, our approach can provide realistic results for a number of practical interactive applications. It can also process highly detailed models containing millions of unorganized triangles in minutes, generating high-quality scattering filters. Resulting simulations compare well with on-site recordings showing that the Kirchhoff approximation can be used for complex scattering problems.Source: Eurographics Symposium on Rendering, pp. 111–120, Grenoble, France, 25-27 Giugno 2007
DOI: 10.2312/egwr/egsr07/111-120
Metrics:
See at:
diglib.eg.org 
| CNR ExploRA
2007
Contribution to conference
Unknown
Investigation of auditory-visual integration in VR Environments
Nguyen K., Dellepiane M., Viaud-Delmon I., Warusfel O.
Investigating the time and spatial constraints under which visual and auditory stimuli are perceived as a unique percept or as spatially coincident has been a topic of numerous researches. However, these findings have been derived up to now in extremely simplified stimulation context consisting in the combination of elementary auditory and visual stimuli usually displayed in dark and anechoic conditions. The present experiment is conducted in a VR environment using a passive stereoscopic display and binaural audio rendering. Subjects have to indicate the point of subjective spatial alignment (PSSA) between a horizontally moving visual stimulus that crosses the direction of a stationary sound. Auditory stimuli are displayed on headphones using individualized head-related transfer functions and the visual stimulus is integrated in a visual background texture in order to convey visual perspective. Two types of audio stimuli are used to evaluate the influence of auditory localisation acuity on the auditory-visual integration: periodic white noise bursts providing optimal localisation cues and periodic 1kHz tone bursts. The present study will indicate whether previous findings (Lewald et al., Behavioural Brain Research, 2001) still hold in more complex audio-visual contexts such as those offered by cutting edge VR environments.Source: 8th International Multisensory Research Forum, Sydney, Australia, 5-7 July 2007
Nguyen K., Dellepiane M., Viaud-Delmon I., Warusfel O.
Investigating the time and spatial constraints under which visual and auditory stimuli are perceived as a unique percept or as spatially coincident has been a topic of numerous researches. However, these findings have been derived up to now in extremely simplified stimulation context consisting in the combination of elementary auditory and visual stimuli usually displayed in dark and anechoic conditions. The present experiment is conducted in a VR environment using a passive stereoscopic display and binaural audio rendering. Subjects have to indicate the point of subjective spatial alignment (PSSA) between a horizontally moving visual stimulus that crosses the direction of a stationary sound. Auditory stimuli are displayed on headphones using individualized head-related transfer functions and the visual stimulus is integrated in a visual background texture in order to convey visual perspective. Two types of audio stimuli are used to evaluate the influence of auditory localisation acuity on the auditory-visual integration: periodic white noise bursts providing optimal localisation cues and periodic 1kHz tone bursts. The present study will indicate whether previous findings (Lewald et al., Behavioural Brain Research, 2001) still hold in more complex audio-visual contexts such as those offered by cutting edge VR environments.Source: 8th International Multisensory Research Forum, Sydney, Australia, 5-7 July 2007
See at: CNR ExploRA
2014
Contribution to journal
Restricted
Introduction to special issue on interacting with the past
Hachet M., Dellepiane M.
The current special issue joins together such examples of fascinating works dedicated to interaction with cultural heritage covering a wide range of possible examples.DOI: 10.1145/2635671
Metrics:
Hachet M., Dellepiane M.
The current special issue joins together such examples of fascinating works dedicated to interaction with cultural heritage covering a wide range of possible examples.DOI: 10.1145/2635671
Metrics:
See at:
dl.acm.org | Journal on Computing and Cultural Heritage | CNR ExploRA
2014
Conference article
Unknown
Site-specific art and 3D: an example of spatial analysis and reconstruction
Dellepiane M., De Matteis M.
Site-specific art is a concept that goes back to the beginning of human race: the works of art were often created by artists taking into account not only their shape and appearance, but also the context in which they would be put. For this reason, moving the artifacts from its original placement (or the changes which happen around it) tend to decrease its impact, and possibly weaken its potentials. Site-specific art is a very powerful concept also for contemporary artists. This paper focuses on the analysis of L.O.V.E., a sculpture from the controversial artist Maurizio Cattelan. Cattelan donated the sculpture to Milano, under the condition that it should not be moved from its original place (in front of Milano Stock Exchange). The aim of the paper is to use 3D reconstruction techniques to show and analyse the monument, stressing its relation with the context around it. A multi-view stereo matching campaign was perfomed to have an accurate reconstruction of the context, then the photos provided by the community were integrated in the reconstruction to show the "point of view" of the people. These data provide interesting indications about the aims of the authors, and they provide additional material for the interpretation of the work of artSource: EG GCH 2014 - 12th EUROGRAPHICS Workshop on Graphics and Cultural Heritage, pp. 29–34, Darmstadt, Germany, 6-8 October 2014
DOI: 10.2312/gch.20141301
Project(s): V-MUST.NET
Metrics:
Dellepiane M., De Matteis M.
Site-specific art is a concept that goes back to the beginning of human race: the works of art were often created by artists taking into account not only their shape and appearance, but also the context in which they would be put. For this reason, moving the artifacts from its original placement (or the changes which happen around it) tend to decrease its impact, and possibly weaken its potentials. Site-specific art is a very powerful concept also for contemporary artists. This paper focuses on the analysis of L.O.V.E., a sculpture from the controversial artist Maurizio Cattelan. Cattelan donated the sculpture to Milano, under the condition that it should not be moved from its original place (in front of Milano Stock Exchange). The aim of the paper is to use 3D reconstruction techniques to show and analyse the monument, stressing its relation with the context around it. A multi-view stereo matching campaign was perfomed to have an accurate reconstruction of the context, then the photos provided by the community were integrated in the reconstruction to show the "point of view" of the people. These data provide interesting indications about the aims of the authors, and they provide additional material for the interpretation of the work of artSource: EG GCH 2014 - 12th EUROGRAPHICS Workshop on Graphics and Cultural Heritage, pp. 29–34, Darmstadt, Germany, 6-8 October 2014
DOI: 10.2312/gch.20141301
Project(s): V-MUST.NET
Metrics:
See at: CNR ExploRA
2006
Journal article
Unknown
Visualization of colour information on highly detailed 3D models
Dellepiane M., Callieri M.
The evolution of technology and important advances in the field of visualization of huge 3D datasets mean that it is now possible to acquire and display detailed 3D models. However, in order to achieve a completely realistic result, high quality colour information must be added to the geometric structure.Source: ERCIM news 67 (2006): 53–54.
Dellepiane M., Callieri M.
The evolution of technology and important advances in the field of visualization of huge 3D datasets mean that it is now possible to acquire and display detailed 3D models. However, in order to achieve a completely realistic result, high quality colour information must be added to the geometric structure.Source: ERCIM news 67 (2006): 53–54.
See at: CNR ExploRA
2006
Software
Unknown
TexAlign
Ganovelli M., Dellepiane M.
Il pacchetto software permette di allineare un set di fotografie digitali ad un modello 3D stimando opportunamente i parametri della camera.
Ganovelli M., Dellepiane M.
Il pacchetto software permette di allineare un set di fotografie digitali ad un modello 3D stimando opportunamente i parametri della camera.
See at: CNR ExploRA
2010
Conference article
Restricted
Using Lego pieces for camera calibration: a preliminary study
Baronti L., Dellepiane M., Scopigno R.
Camera calibration is an important operation for a number of applications in the field of Computer Graphics and Computer Vision. In particular, if the intrinsic parameters of the camera are known in advance, the accuracy of results is extremely improved. For this reason, several easy procedures to calibrate a camera have been proposed. The accuracy and ease-of-use of these procedures is strongly related to the needed calibration target, which is usually a single 2D printed pattern (i.e. a checkerboard). In this paper we propose the use of an alternative: a Lego structure. Lego pieces exhibit several strong-points, like the off-the-shelf availability and the geometric accuracy. Additionally, it's easy to prepare a structure and obtain the corresponding 3D model using freeware tools. Hence, we present the preliminary tests on the use of Lego structures for camera calibration. The tests have been performed on a user-friendly ad-hoc tool, which takes advantage of the peculiar features of Lego to automatically correct the positions of the 2D and 3D correspondences used for calibration. Results show that it's possible to obtain accurate results starting from a few photos, and that the entire procedure can be completed in a very short time.Source: 31st Annual Conference of the European Association for Computer Graphics - Short Papers, pp. 97–100, Norrkoping, Sweden, 4-7 May 2010
Baronti L., Dellepiane M., Scopigno R.
Camera calibration is an important operation for a number of applications in the field of Computer Graphics and Computer Vision. In particular, if the intrinsic parameters of the camera are known in advance, the accuracy of results is extremely improved. For this reason, several easy procedures to calibrate a camera have been proposed. The accuracy and ease-of-use of these procedures is strongly related to the needed calibration target, which is usually a single 2D printed pattern (i.e. a checkerboard). In this paper we propose the use of an alternative: a Lego structure. Lego pieces exhibit several strong-points, like the off-the-shelf availability and the geometric accuracy. Additionally, it's easy to prepare a structure and obtain the corresponding 3D model using freeware tools. Hence, we present the preliminary tests on the use of Lego structures for camera calibration. The tests have been performed on a user-friendly ad-hoc tool, which takes advantage of the peculiar features of Lego to automatically correct the positions of the 2D and 3D correspondences used for calibration. Results show that it's possible to obtain accurate results starting from a few photos, and that the entire procedure can be completed in a very short time.Source: 31st Annual Conference of the European Association for Computer Graphics - Short Papers, pp. 97–100, Norrkoping, Sweden, 4-7 May 2010
See at:
diglib.eg.org | CNR ExploRA
2012
Conference article
Unknown
Teaching 3D acquisition for cultural heritage: a theory and practice approach.
Dellepiane M., Scopigno R.
The paper presents the experience of a course (3D Graphics for Cultural Heritage) in the context of Humanistic Informatics degree. The goal of the course was to present an overview of the techniques for the acquisition of 3D models of real objects. The focus was put on freeware/open source solutions that could give the students the possibility to experiment directly on the data, and possibly apply them in their future activities. The acquisition techniques were divided in three groups: 3D scanning, Dense Stereo Reconstruction and Re-Lightable Images. Moreover, general concepts about 3D Graphics, remote visualization, and planning of projects were part of the subjects. The final project for each student consisted in a practical acquisition of a real objects, using one of the proposed techniques. The results of the projects showed that high quality 3D acquisition is now possible even with low-cost devices and freeware tools, and that it can be a strongpoint for the career of future young CH professionals.Source: Eurographics 2012 - Education papers, pp. 25–32, Cagliari, Italy, 13-18 May 2012
DOI: 10.2312/conf/eg2012/education/025-032
Metrics:
Dellepiane M., Scopigno R.
The paper presents the experience of a course (3D Graphics for Cultural Heritage) in the context of Humanistic Informatics degree. The goal of the course was to present an overview of the techniques for the acquisition of 3D models of real objects. The focus was put on freeware/open source solutions that could give the students the possibility to experiment directly on the data, and possibly apply them in their future activities. The acquisition techniques were divided in three groups: 3D scanning, Dense Stereo Reconstruction and Re-Lightable Images. Moreover, general concepts about 3D Graphics, remote visualization, and planning of projects were part of the subjects. The final project for each student consisted in a practical acquisition of a real objects, using one of the proposed techniques. The results of the projects showed that high quality 3D acquisition is now possible even with low-cost devices and freeware tools, and that it can be a strongpoint for the career of future young CH professionals.Source: Eurographics 2012 - Education papers, pp. 25–32, Cagliari, Italy, 13-18 May 2012
DOI: 10.2312/conf/eg2012/education/025-032
Metrics:
See at: diglib.eg.org | CNR ExploRA
2013
Contribution to conference
Unknown
Which infrastructure support for visual data creation, archiving and visualization?
Scopigno R., Dellepiane M.
Visual data are nowadays a basic component of the massive data gathered in archaeology. With the term visual data we mean any visual representation that could be associated to an artwork, architecture or site, to describe its shape in terms of visual and geometric elements. Therefore, different representations are included: 2D images (standard images, panoramic images, Reflection Transformation Images - RTI), 2D graphical representations such as maps or drawings (usually represented by standard digital image files), 3D models (either sampled or reconstructed with modelling systems) or finally videos (grabbed from reality or computer animations). In the framework of the ARIADNE project, we are focusing on the services that an infrastructure for archaeological documentation should provide for managing these media. Our first goal is to present to users the capabilities of current technology (both commercial tools and resources produced in few recent EU projects) and to understand how to map the real needs of the user community on existing technologies and potential services for production, sharing and visualization. Training is an important component of an infrastructure project, due to the many media available and the complexity of both mastering data creation/presentation and of understanding which media fits better the specific documentation or visual analysis needs. Our purpose will be to help our community in building a clear view of the affordances of particular genres of representations, clarifying their documentation potential and the possible limitations wrt. storing, discovery, accessing, connecting with other data, and rendering. Designing an infrastructure requires also focusing on configuration and/or development (e.g. customization to user needs of open source solutions and of academic prototypes developed by EU projects). Obviously, visual data cannot be treated isolated from the other data. Integration should be designed to allow advanced visual data creation and visualization to inter-operate with standard databases and repositories.Source: CHNT18 - 18th Conference on Cultural Heritage and New Technologies, Vienna, Austria, 11-13 Novembre 2013
Project(s): ARIADNE
Scopigno R., Dellepiane M.
Visual data are nowadays a basic component of the massive data gathered in archaeology. With the term visual data we mean any visual representation that could be associated to an artwork, architecture or site, to describe its shape in terms of visual and geometric elements. Therefore, different representations are included: 2D images (standard images, panoramic images, Reflection Transformation Images - RTI), 2D graphical representations such as maps or drawings (usually represented by standard digital image files), 3D models (either sampled or reconstructed with modelling systems) or finally videos (grabbed from reality or computer animations). In the framework of the ARIADNE project, we are focusing on the services that an infrastructure for archaeological documentation should provide for managing these media. Our first goal is to present to users the capabilities of current technology (both commercial tools and resources produced in few recent EU projects) and to understand how to map the real needs of the user community on existing technologies and potential services for production, sharing and visualization. Training is an important component of an infrastructure project, due to the many media available and the complexity of both mastering data creation/presentation and of understanding which media fits better the specific documentation or visual analysis needs. Our purpose will be to help our community in building a clear view of the affordances of particular genres of representations, clarifying their documentation potential and the possible limitations wrt. storing, discovery, accessing, connecting with other data, and rendering. Designing an infrastructure requires also focusing on configuration and/or development (e.g. customization to user needs of open source solutions and of academic prototypes developed by EU projects). Obviously, visual data cannot be treated isolated from the other data. Integration should be designed to allow advanced visual data creation and visualization to inter-operate with standard databases and repositories.Source: CHNT18 - 18th Conference on Cultural Heritage and New Technologies, Vienna, Austria, 11-13 Novembre 2013
Project(s): ARIADNE
See at: CNR ExploRA
2013
Conference article
Open Access
Edge detection on polynomial texture maps
Brognara C., Corsini M., Dellepiane M., Giachetti A.
In this paper we propose a simple method to extract edges from Polynomial Texture Maps (PTM) or other kinds of Reflection Transformation Image (RTI) files. It is based on the idea of following 2D lines where the variation of corresponding 3D normals computed from the PTM coefficients is maximal. Normals are estimated using a photometric stereo approach, derivatives along image axes directions are computed in a multiscale framework providing normal discontinuity and orientation maps and lines are finally extracted using non-maxima suppression and hysteresis thresholds as in Canny's algorithm. In this way it is possible to discover automatically potential structure of interest (inscriptions, small reliefs) on Cultural Heritage artifacts of interest without the necessity of interactively recreating images using different light directions. Experimental results obtained on test data and new PTMs acquired in an archaeological site in the Holy Land with a simple low-end camera, show that the method provides potentially useful results.Source: ICIAP 2013 - image Analysis and Processing. 17th International Conference, pp. 482–491, Naples, Italy, 9-13 September 2013
DOI: 10.1007/978-3-642-41181-6_49
Metrics:
Brognara C., Corsini M., Dellepiane M., Giachetti A.
In this paper we propose a simple method to extract edges from Polynomial Texture Maps (PTM) or other kinds of Reflection Transformation Image (RTI) files. It is based on the idea of following 2D lines where the variation of corresponding 3D normals computed from the PTM coefficients is maximal. Normals are estimated using a photometric stereo approach, derivatives along image axes directions are computed in a multiscale framework providing normal discontinuity and orientation maps and lines are finally extracted using non-maxima suppression and hysteresis thresholds as in Canny's algorithm. In this way it is possible to discover automatically potential structure of interest (inscriptions, small reliefs) on Cultural Heritage artifacts of interest without the necessity of interactively recreating images using different light directions. Experimental results obtained on test data and new PTMs acquired in an archaeological site in the Holy Land with a simple low-end camera, show that the method provides potentially useful results.Source: ICIAP 2013 - image Analysis and Processing. 17th International Conference, pp. 482–491, Naples, Italy, 9-13 September 2013
DOI: 10.1007/978-3-642-41181-6_49
Metrics:
See at:
link.springer.com | doi.org | link.springer.com | CNR ExploRA
2013
Conference article
Restricted
Digital reconstruction and visualization in archaeology. Case-study drawn from the work of the Swedish Pompeii Project
Dell'Unto N., Ferdani D., Leander A., Dellepiane M., Callieri M., Lindgren S.
The Swedish Pompeii Project started in 2000 as a research and fieldwork activity initiated by the Swedish Institute in Rome. The aim was to record and analyze an entire Pompeian city-block, Insula V 1. Since autumn 2011 a new branch of advanced digital archaeology, involving 3D reconstructions and documentation methods, was added to the project agenda. The insula was completely digitized using laser scanner technology and the raw data were employed to develop different research activities in the area of digital visualization. This paper presents the recent results of the 3D interpretation of the house of Caecilius Iucundus. This research activity was developed employing a large variety of historical and archaeological sources such as: archaeological reports, historical image documentation (printed as well as in edited material) and analysis of the in situ structures. This work was characterized by the experimentation of a new workflow of data development, where the elaboration of the interpreted structures took place directly in virtual space, using the scanned model as geometrical reference. This method easily connected all the historical and archaeological sources collected for the interpretation, opening a new discussion about different possible interpretation of the house. Moreover, a Cave Automatic Virtual Environment (CAVE) was used in different occasions as platform where the different hypotheses could be discussed in the context given by the actual state of the archaeological structures. The use of an accurate and resolute replica of the site as a backdrop for the virtual reconstruction allowed a high level of control on the proposed hypotheses during the interpretation process. This study enabled the acquisition of new and important information about the house, thus, bringing a significant contribution to the archaeological analysis of Insula V 1, suggested as pilot project for wider use.Source: Digital Heritage - 2013 Digital Heritage International Congress, pp. 621–628, Marseille, France, 27 October - 1 November 2013
Dell'Unto N., Ferdani D., Leander A., Dellepiane M., Callieri M., Lindgren S.
The Swedish Pompeii Project started in 2000 as a research and fieldwork activity initiated by the Swedish Institute in Rome. The aim was to record and analyze an entire Pompeian city-block, Insula V 1. Since autumn 2011 a new branch of advanced digital archaeology, involving 3D reconstructions and documentation methods, was added to the project agenda. The insula was completely digitized using laser scanner technology and the raw data were employed to develop different research activities in the area of digital visualization. This paper presents the recent results of the 3D interpretation of the house of Caecilius Iucundus. This research activity was developed employing a large variety of historical and archaeological sources such as: archaeological reports, historical image documentation (printed as well as in edited material) and analysis of the in situ structures. This work was characterized by the experimentation of a new workflow of data development, where the elaboration of the interpreted structures took place directly in virtual space, using the scanned model as geometrical reference. This method easily connected all the historical and archaeological sources collected for the interpretation, opening a new discussion about different possible interpretation of the house. Moreover, a Cave Automatic Virtual Environment (CAVE) was used in different occasions as platform where the different hypotheses could be discussed in the context given by the actual state of the archaeological structures. The use of an accurate and resolute replica of the site as a backdrop for the virtual reconstruction allowed a high level of control on the proposed hypotheses during the interpretation process. This study enabled the acquisition of new and important information about the house, thus, bringing a significant contribution to the archaeological analysis of Insula V 1, suggested as pilot project for wider use.Source: Digital Heritage - 2013 Digital Heritage International Congress, pp. 621–628, Marseille, France, 27 October - 1 November 2013
See at:
www.digitalheritage2013.org | CNR ExploRA
2013
Conference article
Restricted
Global refinement of image-to-geometry registration for color projection
Dellepiane M., Scopigno R.
The management, processing and visualization of color information is a critical subject in the context of the acquisition and visualization of real objects. Especially in the context of Cultural Heritage, artifacts are so complex or hard to handle that the appearance information has to be extracted from a set of images. The images usually have to be registered to the 3D model of the objects, in order to transfer the needed information. Hence, the problem of image-to-geometry registration has been thoroughly studied by the Computer Graphics and Computer Vision community. Several methods have been proposed, but a fully automatic and generic solution is still missing. Moreover, small misalignments often lead to visible artifacts in the final colored 3D models. In this paper, we propose a method to refine the alignment of a group of images which has been already registered to a 3D model. Taking advantage of the overlapping among the images, and applying a statistical global method based on Mutual Information, the registration error is distributed among all the elements of the dataset. Hence, the quality of color projection is improved, especially when dealing with small details. The method was tested on a number of heterogeneous Cultural Heritage objects, bringing to a visible improvement in the rendering quality. The method is fully automatic, and it does not need powerful hardware or long processing time. Hence, it represents a valid solution for a wide application on CH artifacts.Source: Digital Heritage - 2013 Digital Heritage International Congress, pp. 39–46, Marseille, France, 27 October - 1 November 2013
Project(s): HARVEST4D
Dellepiane M., Scopigno R.
The management, processing and visualization of color information is a critical subject in the context of the acquisition and visualization of real objects. Especially in the context of Cultural Heritage, artifacts are so complex or hard to handle that the appearance information has to be extracted from a set of images. The images usually have to be registered to the 3D model of the objects, in order to transfer the needed information. Hence, the problem of image-to-geometry registration has been thoroughly studied by the Computer Graphics and Computer Vision community. Several methods have been proposed, but a fully automatic and generic solution is still missing. Moreover, small misalignments often lead to visible artifacts in the final colored 3D models. In this paper, we propose a method to refine the alignment of a group of images which has been already registered to a 3D model. Taking advantage of the overlapping among the images, and applying a statistical global method based on Mutual Information, the registration error is distributed among all the elements of the dataset. Hence, the quality of color projection is improved, especially when dealing with small details. The method was tested on a number of heterogeneous Cultural Heritage objects, bringing to a visible improvement in the rendering quality. The method is fully automatic, and it does not need powerful hardware or long processing time. Hence, it represents a valid solution for a wide application on CH artifacts.Source: Digital Heritage - 2013 Digital Heritage International Congress, pp. 39–46, Marseille, France, 27 October - 1 November 2013
Project(s): HARVEST4D
See at:
www.digitalheritage2013.org | CNR ExploRA
2013
Contribution to book
Open Access
Pompei revived: scanning Mission - Insula V 1
Dell'Unto N., Dellepiane M., Callieri M., Leander A., Lindgren S., Larsson C.
The Swedish Pompeii Project started in 2000 as a fieldwork initiated from the Swedish Institute in Rome. The aim was to record and analyze a full Pompeian city-block, Insula V 1. This paper presents the initial results of one of the actions in the context of this project. In October 2011, two houses were acquired using 3D scanning and 3d-from-photos techniques, and the data was processed to obtain an accurate and complete model. Through the use of Virtual Reality Techniques, it will be possible to visit the Pompeian houses of Casa del Torello and Casa di Cecilio Giocondo understanding the relation between the actual archaeological context and their original outfit. The collected data will be used also to design and test a web-based access system, where the entire dataset will be available for browsing, measurement and data extraction. The features of HTML5, in particular WebGL, will be used to deliver realtime 3D content and interaction.Source: Archaeology in the Digital Era, edited by Graeme Earl, Tim Sly, Angeliki Chrysanthi, Patricia Murrieta-Flores, Constantinos Papadopoulos, Iza Romanowska, David Wheatley, pp. 199–207. Amsterdam: Amsterdam University Press, 2013
Project(s): 3D-COFORM
Dell'Unto N., Dellepiane M., Callieri M., Leander A., Lindgren S., Larsson C.
The Swedish Pompeii Project started in 2000 as a fieldwork initiated from the Swedish Institute in Rome. The aim was to record and analyze a full Pompeian city-block, Insula V 1. This paper presents the initial results of one of the actions in the context of this project. In October 2011, two houses were acquired using 3D scanning and 3d-from-photos techniques, and the data was processed to obtain an accurate and complete model. Through the use of Virtual Reality Techniques, it will be possible to visit the Pompeian houses of Casa del Torello and Casa di Cecilio Giocondo understanding the relation between the actual archaeological context and their original outfit. The collected data will be used also to design and test a web-based access system, where the entire dataset will be available for browsing, measurement and data extraction. The features of HTML5, in particular WebGL, will be used to deliver realtime 3D content and interaction.Source: Archaeology in the Digital Era, edited by Graeme Earl, Tim Sly, Angeliki Chrysanthi, Patricia Murrieta-Flores, Constantinos Papadopoulos, Iza Romanowska, David Wheatley, pp. 199–207. Amsterdam: Amsterdam University Press, 2013
Project(s): 3D-COFORM
See at:
dare.uva.nl | CNR ExploRA
2014
Contribution to book
Unknown
Training for innovation: data and multimedia visualization
Dellepiane M., Scopigno R.
Among the goals of the ARIADNE project (a digital infrastructure for archaeological documentation), two interrelated objectives are the design of new services (or the integration of existing ones) and the implementation of an intense training & hands-on program. Especially in the case of visual media (which are evolving at an impressing pace) services should be paired by user consultation and training, since a pre-requisite of any service activity is to consolidate knowledge on the potential of new media and the impact those could have in the selected discipline. The latter is the main objective of the TNA training program and of other user consultation events that have been organized in the first 18 months of the ARIADNE project. This short contribution presents the results of this activity and our plans for the design of new services.Source: ARIADNE - The way forward to digital archaeology in Europe, edited by Franco Nicolucci, pp. 35–44, 2014
Project(s): ARIADNE
Dellepiane M., Scopigno R.
Among the goals of the ARIADNE project (a digital infrastructure for archaeological documentation), two interrelated objectives are the design of new services (or the integration of existing ones) and the implementation of an intense training & hands-on program. Especially in the case of visual media (which are evolving at an impressing pace) services should be paired by user consultation and training, since a pre-requisite of any service activity is to consolidate knowledge on the potential of new media and the impact those could have in the selected discipline. The latter is the main objective of the TNA training program and of other user consultation events that have been organized in the first 18 months of the ARIADNE project. This short contribution presents the results of this activity and our plans for the design of new services.Source: ARIADNE - The way forward to digital archaeology in Europe, edited by Franco Nicolucci, pp. 35–44, 2014
Project(s): ARIADNE
See at: CNR ExploRA
2015
Conference article
Open Access
Fast decompression for web-based view-dependent 3D rendering
Ponchio F., Dellepiane M.
Efficient transmission of 3D data to Web clients and mobile applications remains a challenge due to limited bandwidth. Most of the research focus in the context of mesh compression has been on improving compression ratio. However, in this context the use of Javascript on the Web and low power CPUS in mobile applications led to critical computational costs. Progressive decoding improves the user experience by providing a simplified version of the model that refines with time, and it's able to mask latency. Current approaches do so at very poor compression rates or at additional computational cost. The need for better performing algorithms is especially evident with this class of methods where Limper [Limper et al. 2013b] demonstrated how decoding time becomes a limiting factor even at moderately low bandwidths. In this paper we present a novel multi-resolution WebGL based rendering algorithm which combines progressive loading, view-dependent resolution and mesh compression, providing high frame rates and a decoding speed of million of triangles per second in Javascript. This method is parallelizable, robust to non-manifold meshes, and scalable to very large models.Source: 20th International Conference on 3D Web Technology, pp. 199–207, Heraklion, Crete, Greece, 18-21/06/2015
DOI: 10.1145/2775292.2775308
Project(s): HARVEST4D
Metrics:
Ponchio F., Dellepiane M.
Efficient transmission of 3D data to Web clients and mobile applications remains a challenge due to limited bandwidth. Most of the research focus in the context of mesh compression has been on improving compression ratio. However, in this context the use of Javascript on the Web and low power CPUS in mobile applications led to critical computational costs. Progressive decoding improves the user experience by providing a simplified version of the model that refines with time, and it's able to mask latency. Current approaches do so at very poor compression rates or at additional computational cost. The need for better performing algorithms is especially evident with this class of methods where Limper [Limper et al. 2013b] demonstrated how decoding time becomes a limiting factor even at moderately low bandwidths. In this paper we present a novel multi-resolution WebGL based rendering algorithm which combines progressive loading, view-dependent resolution and mesh compression, providing high frame rates and a decoding speed of million of triangles per second in Javascript. This method is parallelizable, robust to non-manifold meshes, and scalable to very large models.Source: 20th International Conference on 3D Web Technology, pp. 199–207, Heraklion, Crete, Greece, 18-21/06/2015
DOI: 10.1145/2775292.2775308
Project(s): HARVEST4D
Metrics:
See at:
ISTI Repository | dl.acm.org | doi.org | CNR ExploRA
2016
Journal article
Open Access
Web-based visualization for 3D data in archaeology: The ADS 3D viewer
Galeazzi F., Callieri M., Dellepiane M., Charno M., Richards J., Scopigno R.
The solid geometry of archaeological deposits is fundamental to the interpretation of their chronological sequence. However, such stratigraphic sequences are generally viewed as static two-dimensional diagrammatic representations which are difficult to manipulate or to relate to real layers. The ADS 3D Viewer is a web-based resource for the management and analysis of archaeological data. The viewer was developed to take advantage of recent developments in web technology, namely the adoption of WebGL (Web Graphics Library) by current web browsers. The ADS 3D Viewer combines the potential of the 3D Heritage Online Presenter (3DHOP), a software package for the web-based visualization of 3D geometries, with the infrastructure of the Archaeology Data Service (ADS) repository, in the attempt to create a platform for the visualization and analysis of 3D data archived by the ADS.Two versions of the viewer have been developed to answer the needs of different users. The first version, the Object Level 3D Viewer, was implemented to extend the browsing capability of ADS project archives by enabling the visualization of single 3D models. The second version, the Stratigraphy 3D Viewer, is an extension which allows the exploration of a specific kind of aggregated data: the multiple layers of an archaeological stratigraphic sequence. This allows those unable to participate directly in the fieldwork to access, analyse and re-interpret the archaeological context remotely. This has the potential to transform the discipline, allowing inter-disciplinary, cross-border and 'at-distance' collaborative workflows, and enabling easier access to and analysis of archaeological data.Source: Journal of Archaeological Science: Reports (Print) 9 (2016): 1–11. doi:10.1016/j.jasrep.2016.06.045
DOI: 10.1016/j.jasrep.2016.06.045
Metrics:
Galeazzi F., Callieri M., Dellepiane M., Charno M., Richards J., Scopigno R.
The solid geometry of archaeological deposits is fundamental to the interpretation of their chronological sequence. However, such stratigraphic sequences are generally viewed as static two-dimensional diagrammatic representations which are difficult to manipulate or to relate to real layers. The ADS 3D Viewer is a web-based resource for the management and analysis of archaeological data. The viewer was developed to take advantage of recent developments in web technology, namely the adoption of WebGL (Web Graphics Library) by current web browsers. The ADS 3D Viewer combines the potential of the 3D Heritage Online Presenter (3DHOP), a software package for the web-based visualization of 3D geometries, with the infrastructure of the Archaeology Data Service (ADS) repository, in the attempt to create a platform for the visualization and analysis of 3D data archived by the ADS.Two versions of the viewer have been developed to answer the needs of different users. The first version, the Object Level 3D Viewer, was implemented to extend the browsing capability of ADS project archives by enabling the visualization of single 3D models. The second version, the Stratigraphy 3D Viewer, is an extension which allows the exploration of a specific kind of aggregated data: the multiple layers of an archaeological stratigraphic sequence. This allows those unable to participate directly in the fieldwork to access, analyse and re-interpret the archaeological context remotely. This has the potential to transform the discipline, allowing inter-disciplinary, cross-border and 'at-distance' collaborative workflows, and enabling easier access to and analysis of archaeological data.Source: Journal of Archaeological Science: Reports (Print) 9 (2016): 1–11. doi:10.1016/j.jasrep.2016.06.045
DOI: 10.1016/j.jasrep.2016.06.045
Metrics:
See at:
Journal of Archaeological Science Reports | ISTI Repository | Journal of Archaeological Science Reports | www.sciencedirect.com | CNR ExploRA
2016
Journal article
Open Access
Relative Scale Estimation and 3D Registration of Multi-Modal Geometry Using Growing Least Squares
Mellado N., Dellepiane M., Scopigno R.
The advent of low cost scanning devices and the improvement of multi-view stereo techniques have made the acquisition of 3D geometry ubiquitous. Data gathered from different devices, however, result in large variations in detail, scale, and coverage. Registration of such data is essential before visualizing, comparing and archiving them. However, state-of-the-art methods for geometry registration cannot be directly applied due to intrinsic differences between the models, e.g., sampling, scale, noise. In this paper we present a method for the automatic registration of multi-modal geometric data, i.e., acquired by devices with different properties (e.g., resolution, noise, data scaling). The method uses a descriptor based on Growing Least Squares, and is robust to noise, variation in sampling density, details, and enables scale-invariant matching. It allows not only the measurement of the similarity between the geometry surrounding two points, but also the estimation of their relative scale. As it is computed locally, it can be used to analyze large point clouds composed of millions of points. We implemented our approach in two registration procedures (assisted and automatic) and applied them successfully on a number of synthetic and real cases. We show that using our method, multi-modal models can be automatically registered, regardless of their differences in noise, detail, scale, and unknown relative coverage.Source: IEEE transactions on visualization and computer graphics 22 (2016): 2160–2173. doi:10.1109/TVCG.2015.2505287
DOI: 10.1109/tvcg.2015.2505287
Project(s): HARVEST4D, SMARTGEOMETRY
Metrics:
Mellado N., Dellepiane M., Scopigno R.
The advent of low cost scanning devices and the improvement of multi-view stereo techniques have made the acquisition of 3D geometry ubiquitous. Data gathered from different devices, however, result in large variations in detail, scale, and coverage. Registration of such data is essential before visualizing, comparing and archiving them. However, state-of-the-art methods for geometry registration cannot be directly applied due to intrinsic differences between the models, e.g., sampling, scale, noise. In this paper we present a method for the automatic registration of multi-modal geometric data, i.e., acquired by devices with different properties (e.g., resolution, noise, data scaling). The method uses a descriptor based on Growing Least Squares, and is robust to noise, variation in sampling density, details, and enables scale-invariant matching. It allows not only the measurement of the similarity between the geometry surrounding two points, but also the estimation of their relative scale. As it is computed locally, it can be used to analyze large point clouds composed of millions of points. We implemented our approach in two registration procedures (assisted and automatic) and applied them successfully on a number of synthetic and real cases. We show that using our method, multi-modal models can be automatically registered, regardless of their differences in noise, detail, scale, and unknown relative coverage.Source: IEEE transactions on visualization and computer graphics 22 (2016): 2160–2173. doi:10.1109/TVCG.2015.2505287
DOI: 10.1109/tvcg.2015.2505287
Project(s): HARVEST4D
, SMARTGEOMETRY Metrics:
See at:
IEEE Transactions on Visualization and Computer Graphics | ISTI Repository | IEEE Transactions on Visualization and Computer Graphics | HAL Descartes | ieeexplore.ieee.org | CNR ExploRA
2016
Journal article
Open Access
Multiresolution and fast decompression for optimal web-based rendering
Ponchio F., Dellepiane M.
Limited bandwidth is a strong constraint when efficient transmission of 3D data to Web clients and mobile applications is needed. In this paper we present a novel multi-resolution WebGL based rendering algorithm which combines progressive loading, view-dependent resolution and mesh compression, providing high frame rates and a decoding speed of million of triangles per second in JavaScript. The method is parallelizable and scalable to very large models. The algorithm is based on the local multi-resolution approaches provided by the community, but ad-hoc solutions had to be studied and implemented to provide adequate performances. In particular, a compression mechanism that reached very high compression rate without impact on rendering performance was implemented. Moreover, the data partition strategy was modified in order to be able to load different types of data (i.e. point clouds) and better adapt to the potentials and limitations of web-based rendering.Source: Graphical models (Print) 88 (2016): 1–11. doi:10.1016/j.gmod.2016.09.002
DOI: 10.1016/j.gmod.2016.09.002
Project(s): ARIADNE, HARVEST4D
Metrics:
Ponchio F., Dellepiane M.
Limited bandwidth is a strong constraint when efficient transmission of 3D data to Web clients and mobile applications is needed. In this paper we present a novel multi-resolution WebGL based rendering algorithm which combines progressive loading, view-dependent resolution and mesh compression, providing high frame rates and a decoding speed of million of triangles per second in JavaScript. The method is parallelizable and scalable to very large models. The algorithm is based on the local multi-resolution approaches provided by the community, but ad-hoc solutions had to be studied and implemented to provide adequate performances. In particular, a compression mechanism that reached very high compression rate without impact on rendering performance was implemented. Moreover, the data partition strategy was modified in order to be able to load different types of data (i.e. point clouds) and better adapt to the potentials and limitations of web-based rendering.Source: Graphical models (Print) 88 (2016): 1–11. doi:10.1016/j.gmod.2016.09.002
DOI: 10.1016/j.gmod.2016.09.002
Project(s): ARIADNE
, HARVEST4D Metrics:
See at:
ISTI Repository | Graphical Models | www.sciencedirect.com | CNR ExploRA
2017
Contribution to book
Restricted
Integration and analysis of sampled data: visualization approaches and platforms
Scopigno R., Dellepiane M.
The evolution of digitization technologies (2D and 3D) and the consequent wide availability of digital representations of artworks has ignited a number of works aimed at providing tools and platforms for archival, visual presentation, and integration of all those media. This chapter reviews some available instruments, focusing first on the platforms that could support the CH/DH professional in the single or cross-analysis of multimedia representations. Then, we discuss the available approaches for structuring and integrating the available data, presenting both the GIS-based solutions and the more recent Web-based systems. Some discussion on open issues concludes the contribution.Source: Sensing the Past : from artifact to historical site, edited by Nicola Masini, Francesco Soldovieri, pp. 377–393, 2017
DOI: 10.1007/978-3-319-50518-3
Metrics:
Scopigno R., Dellepiane M.
The evolution of digitization technologies (2D and 3D) and the consequent wide availability of digital representations of artworks has ignited a number of works aimed at providing tools and platforms for archival, visual presentation, and integration of all those media. This chapter reviews some available instruments, focusing first on the platforms that could support the CH/DH professional in the single or cross-analysis of multimedia representations. Then, we discuss the available approaches for structuring and integrating the available data, presenting both the GIS-based solutions and the more recent Web-based systems. Some discussion on open issues concludes the contribution.Source: Sensing the Past : from artifact to historical site, edited by Nicola Masini, Francesco Soldovieri, pp. 377–393, 2017
DOI: 10.1007/978-3-319-50518-3
Metrics:
See at:
doi.org | link.springer.com | CNR ExploRA