2007
Journal article
Open Access
Watermarked 3-D Mesh Quality Assessment
Corsini M., Drelie Gelasca E., Ebrahimi T., Barni M.
This paper addresses the problem of assessing distortions produced by watermarking 3-D meshes. In particular, a new methodology for subjective evaluation of the quality of 3-D objects is proposed and implemented. Two objective metrics derived from measures of surface roughness are then proposed and their efficiency to predict the perceptual impact of 3-D watermarking is assessed and compared with the state of the art. Results obtained showgood correlations between the proposed objective metrics and subjective assessments by human observers.Source: IEEE transactions on multimedia 9 (2007): 247–256. doi:10.1109/TMM.2006.886261
DOI: 10.1109/tmm.2006.886261
Metrics:
Corsini M., Drelie Gelasca E., Ebrahimi T., Barni M.
This paper addresses the problem of assessing distortions produced by watermarking 3-D meshes. In particular, a new methodology for subjective evaluation of the quality of 3-D objects is proposed and implemented. Two objective metrics derived from measures of surface roughness are then proposed and their efficiency to predict the perceptual impact of 3-D watermarking is assessed and compared with the state of the art. Results obtained showgood correlations between the proposed objective metrics and subjective assessments by human observers.Source: IEEE transactions on multimedia 9 (2007): 247–256. doi:10.1109/TMM.2006.886261
DOI: 10.1109/tmm.2006.886261
Metrics:
See at:
Infoscience - EPFL scientific publications 
| IEEE Transactions on Multimedia | IEEE Transactions on Multimedia 
| ieeexplore.ieee.org | CNR ExploRA
2010
Journal article
Open Access
A comparison of perceptually-based metrics for objective evaluation of geometry processing
Lavoue G., Corsini M.
Recent advances in 3D graphics technologies have led to an increasing use of processing techniques on 3D meshes, such as filtering, compression, watermarking, simplification, deformation and so forth. Since these processes may modify the visual appearance of the 3D objects, several metrics have been introduced to properly drive or evaluate them, from classic geometric ones such as Hausdorff distance, to more complex perceptually-based measures. This paper presents a survey on existing perceptuallybased metrics for visual impairment of 3D objects and provides an extensive comparison between them. In particular, different scenarios which correspond to different perceptual and cognitive mechanisms are analyzed. The objective is twofold: (1) catching the behavior of existing measures to help Perception researchers for designing new 3D metrics and (2) providing a comparison between them to inform and help Computer Graphics researchers for choosing the most accurate tool for the design and the evaluation of their mesh processing algorithms.Source: IEEE transactions on multimedia 12 (2010): 636–649. doi:10.1109/TMM.2010.2060475
DOI: 10.1109/tmm.2010.2060475
Metrics:
Lavoue G., Corsini M.
Recent advances in 3D graphics technologies have led to an increasing use of processing techniques on 3D meshes, such as filtering, compression, watermarking, simplification, deformation and so forth. Since these processes may modify the visual appearance of the 3D objects, several metrics have been introduced to properly drive or evaluate them, from classic geometric ones such as Hausdorff distance, to more complex perceptually-based measures. This paper presents a survey on existing perceptuallybased metrics for visual impairment of 3D objects and provides an extensive comparison between them. In particular, different scenarios which correspond to different perceptual and cognitive mechanisms are analyzed. The objective is twofold: (1) catching the behavior of existing measures to help Perception researchers for designing new 3D metrics and (2) providing a comparison between them to inform and help Computer Graphics researchers for choosing the most accurate tool for the design and the evaluation of their mesh processing algorithms.Source: IEEE transactions on multimedia 12 (2010): 636–649. doi:10.1109/TMM.2010.2060475
DOI: 10.1109/tmm.2010.2060475
Metrics:
See at:
IEEE Transactions on Multimedia | IEEE Transactions on Multimedia | CNR ExploRA
2006
Software
Unknown
HPTMBrowser
Corsini M.
Il pacchetto software permette di visualizzare PTM (polynomial Texture Maps) ad alta risoluzione in rete.
Corsini M.
Il pacchetto software permette di visualizzare PTM (polynomial Texture Maps) ad alta risoluzione in rete.
See at: CNR ExploRA
2006
Software
Unknown
PhotoTuner
Massimiliano Corsini
Il prodotto software permette di calibrare il colore di un set di immagini digitali utilizzando la tavola di MacBeth.
Massimiliano Corsini
Il prodotto software permette di calibrare il colore di un set di immagini digitali utilizzando la tavola di MacBeth.
See at: CNR ExploRA
2013
Journal article
Open Access
Perceptual metrics for static and dynamic triangle meshes
Corsini M., Larabi M. C., Lavoué G., Petrík O., Vása L., Wang K.
Almost all mesh processing procedures cause some more or less visible changes in the appearance of objects represented by polygonal meshes. In many cases, such as mesh watermarking, simplification or lossy compression, the objective is to make the change in appearance negligible, or as small as possible, given some other constraints. Measuring the amount of distortion requires taking into account the final purpose of the data. In many applications, the final consumer of the data is a human observer, and therefore the perceptibility of the introduced appearance change by a human observer should be the criterion that is taken into account when designing and configuring the processing algorithms. In this review, we discuss the existing comparison metrics for static and dynamic (animated) triangle meshes. We describe the concepts used in perception-oriented metrics used for 2D image comparison, and we show how these concepts are employed in existing 3D mesh metrics. We describe the character of subjective data used for evaluation of mesh metrics and provide comparison results identifying the advantages and drawbacks of each method. Finally, we also discuss employing the perception-correlated metrics in perception-oriented mesh processing algorithms.Source: Computer graphics forum (Online) 32 (2013): 125. doi:10.1111/cgf.12001
DOI: 10.1111/cgf.12001
Metrics:
Corsini M., Larabi M. C., Lavoué G., Petrík O., Vása L., Wang K.
Almost all mesh processing procedures cause some more or less visible changes in the appearance of objects represented by polygonal meshes. In many cases, such as mesh watermarking, simplification or lossy compression, the objective is to make the change in appearance negligible, or as small as possible, given some other constraints. Measuring the amount of distortion requires taking into account the final purpose of the data. In many applications, the final consumer of the data is a human observer, and therefore the perceptibility of the introduced appearance change by a human observer should be the criterion that is taken into account when designing and configuring the processing algorithms. In this review, we discuss the existing comparison metrics for static and dynamic (animated) triangle meshes. We describe the concepts used in perception-oriented metrics used for 2D image comparison, and we show how these concepts are employed in existing 3D mesh metrics. We describe the character of subjective data used for evaluation of mesh metrics and provide comparison results identifying the advantages and drawbacks of each method. Finally, we also discuss employing the perception-correlated metrics in perception-oriented mesh processing algorithms.Source: Computer graphics forum (Online) 32 (2013): 125. doi:10.1111/cgf.12001
DOI: 10.1111/cgf.12001
Metrics:
See at:
Computer Graphics Forum | Computer Graphics Forum | Hyper Article en Ligne | Hyper Article en Ligne | onlinelibrary.wiley.com | CNR ExploRA
2014
Conference article
Restricted
The common implementation framework as service - Towards novel applications for streamlined presentation of 3D content on the Web
Aderhold A., Wilkosinska K., Corsini M., Jung Y., Graf H., Kuijper A.
We solve a standing issue of the recently published Common Implementation Framework (CIF) for Online Virtual Museums: programmatic access to the transcoding, optimization and template rendering infrastructure of the CIF. We propose a method that enables researchers and developers to build novel systems on top of the CIF infrastructure beyond its current Cultural Heritage workflow. Therefore, we introduce a way to programmatically access the powerful backend of the CIF through a universal access layer, addressable by standards like HTTP and the JSON Data Interchange Format. In order to demonstrate our approach, we present two different use cases in which the CIF pipeline is utilized as a service through the proposed resource-based access layer: a native mobile iOS application for browsing 3D model repositories realizing just-in-time optimization of large models, and a MeshLab plugin to asynchronously convert and prepare a model for the Web.Source: DUXU 2014 - Design, User Experience, and Usability. User Experience Design for Diverse Interaction Platforms and Environments. Third International Conference, held as Part of HCI International 2014, pp. 3–14, Heraklion, Crete, 22-27 June 2014
DOI: 10.1007/978-3-319-07626-3_1
Project(s): V-MUST.NET
Metrics:
Aderhold A., Wilkosinska K., Corsini M., Jung Y., Graf H., Kuijper A.
We solve a standing issue of the recently published Common Implementation Framework (CIF) for Online Virtual Museums: programmatic access to the transcoding, optimization and template rendering infrastructure of the CIF. We propose a method that enables researchers and developers to build novel systems on top of the CIF infrastructure beyond its current Cultural Heritage workflow. Therefore, we introduce a way to programmatically access the powerful backend of the CIF through a universal access layer, addressable by standards like HTTP and the JSON Data Interchange Format. In order to demonstrate our approach, we present two different use cases in which the CIF pipeline is utilized as a service through the proposed resource-based access layer: a native mobile iOS application for browsing 3D model repositories realizing just-in-time optimization of large models, and a MeshLab plugin to asynchronously convert and prepare a model for the Web.Source: DUXU 2014 - Design, User Experience, and Usability. User Experience Design for Diverse Interaction Platforms and Environments. Third International Conference, held as Part of HCI International 2014, pp. 3–14, Heraklion, Crete, 22-27 June 2014
DOI: 10.1007/978-3-319-07626-3_1
Project(s): V-MUST.NET
Metrics:
See at:
doi.org | CNR ExploRA
2020
Contribution to journal
Embargo
Foreword to the special section on smart tool and applications for graphics (STAG 2019)
Agus M., Corsini M., Pintus R.
Source: Computers & graphics 91 (2020): A3–A4. doi:10.1016/j.cag.2020.05.027
DOI: 10.1016/j.cag.2020.05.027
Metrics:
Agus M., Corsini M., Pintus R.
Source: Computers & graphics 91 (2020): A3–A4. doi:10.1016/j.cag.2020.05.027
DOI: 10.1016/j.cag.2020.05.027
Metrics:
See at:
Computers & Graphics | www.sciencedirect.com | CNR ExploRA
2021
Journal article
Open Access
Multimodal attention networks for low-level vision-and-language navigation
Landi F., Baraldi L., Cornia M., Corsini M., Cucchiara R.
Vision-and-Language Navigation (VLN) is a challenging task in which an agent needs to follow a language-specified path to reach a target destination. The goal gets even harder as the actions available to the agent get simpler and move towards low-level, atomic interactions with the environment. This setting takes the name of low-level VLN. In this paper, we strive for the creation of an agent able to tackle three key issues: multi-modality, long-term dependencies, and adaptability towards different locomotive settings. To that end, we devise "Perceive, Transform, and Act" (PTA): a fully-attentive VLN architecture that leaves the recurrent approach behind and the first Transformer-like architecture incorporating three different modalities -- natural language, images, and low-level actions for the agent control. In particular, we adopt an early fusion strategy to merge lingual and visual information efficiently in our encoder. We then propose to refine the decoding phase with a late fusion extension between the agent's history of actions and the perceptual modalities. We experimentally validate our model on two datasets: PTA achieves promising results in low-level VLN on R2R and achieves good performance in the recently proposed R4R benchmark.Source: Computer vision and image understanding (Print) 210 (2021). doi:10.1016/j.cviu.2021.103255
DOI: 10.1016/j.cviu.2021.103255
Metrics:
Landi F., Baraldi L., Cornia M., Corsini M., Cucchiara R.
Vision-and-Language Navigation (VLN) is a challenging task in which an agent needs to follow a language-specified path to reach a target destination. The goal gets even harder as the actions available to the agent get simpler and move towards low-level, atomic interactions with the environment. This setting takes the name of low-level VLN. In this paper, we strive for the creation of an agent able to tackle three key issues: multi-modality, long-term dependencies, and adaptability towards different locomotive settings. To that end, we devise "Perceive, Transform, and Act" (PTA): a fully-attentive VLN architecture that leaves the recurrent approach behind and the first Transformer-like architecture incorporating three different modalities -- natural language, images, and low-level actions for the agent control. In particular, we adopt an early fusion strategy to merge lingual and visual information efficiently in our encoder. We then propose to refine the decoding phase with a late fusion extension between the agent's history of actions and the perceptual modalities. We experimentally validate our model on two datasets: PTA achieves promising results in low-level VLN on R2R and achieves good performance in the recently proposed R4R benchmark.Source: Computer vision and image understanding (Print) 210 (2021). doi:10.1016/j.cviu.2021.103255
DOI: 10.1016/j.cviu.2021.103255
Metrics:
See at:
ISTI Repository | www.sciencedirect.com | CNR ExploRA
2009
Journal article
Restricted
eNVyMyCar: a multiplayer car racing game for teaching computer graphics
Ganovelli F., Corsini M.
The development of a computer game is widely used as a way of conveying concepts regarding Computer Science. There are several reasons for this: it stimulates creativity, it provides an immediate sense of achievement (when the code works), it typically covers all the aspects of an introductory course, and it is easy to find ideas just by looking around and finding stimulation from one's environment and from fellow students. In this paper we present eNVyMyCar, a framework for the collaborative/competitive development of a computer game, and report the experience of its use in two Computer Graphics courses held in 2007. We developed a multiplayer car racing game where the student's task is just to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and are transparent to the developer. The innovative feature of our framework is that all on-line users can see the views produced by their fellow students. This motivates students to improve their work by comparing it with other students and picking up ideas from them. It also gives students an opportunity to show off to their classmates.Source: Computer graphics forum (Print) 28 (2009): 2025–2032. doi:10.1111/j.1467-8659.2009.01425.x
DOI: 10.1111/j.1467-8659.2009.01425.x
Metrics:
Ganovelli F., Corsini M.
The development of a computer game is widely used as a way of conveying concepts regarding Computer Science. There are several reasons for this: it stimulates creativity, it provides an immediate sense of achievement (when the code works), it typically covers all the aspects of an introductory course, and it is easy to find ideas just by looking around and finding stimulation from one's environment and from fellow students. In this paper we present eNVyMyCar, a framework for the collaborative/competitive development of a computer game, and report the experience of its use in two Computer Graphics courses held in 2007. We developed a multiplayer car racing game where the student's task is just to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and are transparent to the developer. The innovative feature of our framework is that all on-line users can see the views produced by their fellow students. This motivates students to improve their work by comparing it with other students and picking up ideas from them. It also gives students an opportunity to show off to their classmates.Source: Computer graphics forum (Print) 28 (2009): 2025–2032. doi:10.1111/j.1467-8659.2009.01425.x
DOI: 10.1111/j.1467-8659.2009.01425.x
Metrics:
See at:
Computer Graphics Forum | onlinelibrary.wiley.com | CNR ExploRA
2007
Conference article
Unknown
CENOBIUM Cultural Electronic Network Online: Binding Up Interoperably Usable Multimedia
Baracchini C., Callieri M., Corsini M., Dellepiane M., Dercks U., Keultjes D., Montani C., Scognamiglio M., Scopigno R., Sigismondi R., Wolf G.
CENOBIUM project is a multimedia presentation of Romanesque cloister capitals from the Mediterranean region. High-resolution digital photographs, 3-D models, and panoramas will virtually link the capitals to their original surroundings, thus representing them within their original architectural and conceptual contexts. The cloister of Monreale is the starting point of this project, which combines classical and innovative methods of Art History with the latest in multimedia data technology. The paper describes the different acquisition and documentation; it also outlines the main components of the system which will allow the user to virtually explore the cloister.Source: Electronic Imaging & the Visual Arts. EVA 2007 Florence, Florence, Italy, March 2007
Baracchini C., Callieri M., Corsini M., Dellepiane M., Dercks U., Keultjes D., Montani C., Scognamiglio M., Scopigno R., Sigismondi R., Wolf G.
CENOBIUM project is a multimedia presentation of Romanesque cloister capitals from the Mediterranean region. High-resolution digital photographs, 3-D models, and panoramas will virtually link the capitals to their original surroundings, thus representing them within their original architectural and conceptual contexts. The cloister of Monreale is the starting point of this project, which combines classical and innovative methods of Art History with the latest in multimedia data technology. The paper describes the different acquisition and documentation; it also outlines the main components of the system which will allow the user to virtually explore the cloister.Source: Electronic Imaging & the Visual Arts. EVA 2007 Florence, Florence, Italy, March 2007
See at: CNR ExploRA
2008
Conference article
Restricted
EnVyMyCar: a multi-player car racing game for teaching computer graphics
Ganovelli F., Corsini M.
The development of a computer game is widely used as a means to convey Computer Sciences concepts. There are several reasons for that: it is stimulates creativity, it provides an immediate sense of achievement when the code works, it typically covers all the aspects of an introductory course, it is easy to find ideas just looking around. In this paper we present NVMC (EnVy My Car), a framework for collaborative/competitive development of a computer game and report the experience in using it in two computer graphics courses held in the year 2007 by the authors. We developed a multiplayer car racing game where the student is only asked to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and transparent to the developer. The novelty of our framework is that all the clients on-line are able to see the views provided by the other clients, which serves to motivate the students to improve their work by comparing it with the other clients, as a means to pick up ideas from the others and finally to show off with their classmates.Source: Eurographics 2008 - Education Papers, Crete, Greece, 14-18/04/2008
DOI: 10.2312/eged.20081000
Metrics:
Ganovelli F., Corsini M.
The development of a computer game is widely used as a means to convey Computer Sciences concepts. There are several reasons for that: it is stimulates creativity, it provides an immediate sense of achievement when the code works, it typically covers all the aspects of an introductory course, it is easy to find ideas just looking around. In this paper we present NVMC (EnVy My Car), a framework for collaborative/competitive development of a computer game and report the experience in using it in two computer graphics courses held in the year 2007 by the authors. We developed a multiplayer car racing game where the student is only asked to implement the rendering of the scene, while all the other aspects, communication and synchronization are implemented in the framework and transparent to the developer. The novelty of our framework is that all the clients on-line are able to see the views provided by the other clients, which serves to motivate the students to improve their work by comparing it with the other clients, as a means to pick up ideas from the others and finally to show off with their classmates.Source: Eurographics 2008 - Education Papers, Crete, Greece, 14-18/04/2008
DOI: 10.2312/eged.20081000
Metrics:
See at:
diglib.eg.org | CNR ExploRA
2005
Report
Open Access
Watermarked 3D mesh quality assessment
Corsini M., Drelie Gelasca E., Touradj E., Barni M.
This paper addresses the problem of assessing distortions produced by watermarking 3D meshes. In particular, a new methodology for subjective evaluation of the quality of 3D objects is proposed and implemented. Two objective metrics derived from measures of surface roughness are then proposed and their efficiency to predict perceptual impact of 3D watermarking are assessed and compared with the state of the art. Results obtained show good correlations between the proposed objective metrics and subjective assessments by human observers.Source: ISTI Technical reports, 2005
Corsini M., Drelie Gelasca E., Touradj E., Barni M.
This paper addresses the problem of assessing distortions produced by watermarking 3D meshes. In particular, a new methodology for subjective evaluation of the quality of 3D objects is proposed and implemented. Two objective metrics derived from measures of surface roughness are then proposed and their efficiency to predict perceptual impact of 3D watermarking are assessed and compared with the state of the art. Results obtained show good correlations between the proposed objective metrics and subjective assessments by human observers.Source: ISTI Technical reports, 2005
See at:
ISTI Repository | 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
2021
Journal article
Open Access
CHARITY: Cloud for holography and cross reality
Dazzi P., Corsini M.
ISTI-CNR is involved in the H2020 CHARITY project (Cloud for HologrAphy and Cross RealITY), which started in January 2021. The project aims to leverage the benefits of intelligent, autonomous orchestration of a heterogeneous set of cloud, edge, and network resources, to create a symbiotic relationship between low and high latency infrastructures that will facilitate the needs of emerging applications.Source: ERCIM news online edition 126 (2021): 46–47.
Dazzi P., Corsini M.
ISTI-CNR is involved in the H2020 CHARITY project (Cloud for HologrAphy and Cross RealITY), which started in January 2021. The project aims to leverage the benefits of intelligent, autonomous orchestration of a heterogeneous set of cloud, edge, and network resources, to create a symbiotic relationship between low and high latency infrastructures that will facilitate the needs of emerging applications.Source: ERCIM news online edition 126 (2021): 46–47.
See at:
ercim-news.ercim.eu | ISTI Repository | CNR ExploRA
2008
Journal article
Open Access
Masked photo blending: mapping dense photographic data set on high-resolution sampled 3D models
Callieri M., Cignoni P., Corsini M., Scopigno R.
The technological advance of sensors is producing an exponential size growth of the data coming from 3D scanning and digital photography. The production of digital 3D models consisting of tens or even hundreds of millions of triangles is quite easy nowadays; at the same time, using high-resolution digital cameras it is also straightforward to produce a set of pictures of the same real object totalling more than 50M Pixel. The problem is how to manage all this data to produce 3D models that could fit the interactive rendering constraints. A common approach is to go for mesh parametrization and texture synthesis, but finding a parametrization for such large meshes and managing such large textures can be prohibitive. Moreover, digital photo sampling produces highly redundant data; this redundancy should be eliminated while mapping to the 3D model but, at the same time, should also be efficiently used to improve the sampled data coherence and the appearance representation accuracy. In this paper we present an approach where a multivariate blending function weights all the available pixel data with respect to geometric, topological and colorimetric criteria. The blending approach proposed is efficient, since it mostly works independently on each image, and can be easily extended to include other image quality estimators. The resulting weighted pixels are then selectively mapped on the geometry, preferably by adopting a multiresolution per-vertex encoding to make profitable use of all the data available and to avoid the texture size bottleneck. Some practical examples on complex datasets are presented.Source: Computers & graphics 32 (2008): 464–473. doi:10.1016/j.cag.2008.05.004
DOI: 10.1016/j.cag.2008.05.004
Metrics:
Callieri M., Cignoni P., Corsini M., Scopigno R.
The technological advance of sensors is producing an exponential size growth of the data coming from 3D scanning and digital photography. The production of digital 3D models consisting of tens or even hundreds of millions of triangles is quite easy nowadays; at the same time, using high-resolution digital cameras it is also straightforward to produce a set of pictures of the same real object totalling more than 50M Pixel. The problem is how to manage all this data to produce 3D models that could fit the interactive rendering constraints. A common approach is to go for mesh parametrization and texture synthesis, but finding a parametrization for such large meshes and managing such large textures can be prohibitive. Moreover, digital photo sampling produces highly redundant data; this redundancy should be eliminated while mapping to the 3D model but, at the same time, should also be efficiently used to improve the sampled data coherence and the appearance representation accuracy. In this paper we present an approach where a multivariate blending function weights all the available pixel data with respect to geometric, topological and colorimetric criteria. The blending approach proposed is efficient, since it mostly works independently on each image, and can be easily extended to include other image quality estimators. The resulting weighted pixels are then selectively mapped on the geometry, preferably by adopting a multiresolution per-vertex encoding to make profitable use of all the data available and to avoid the texture size bottleneck. Some practical examples on complex datasets are presented.Source: Computers & graphics 32 (2008): 464–473. doi:10.1016/j.cag.2008.05.004
DOI: 10.1016/j.cag.2008.05.004
Metrics:
See at:
Computers & Graphics | Computers & Graphics | CNR ExploRA
2008
Journal article
Restricted
Stereo light probe
Corsini M., Callieri M., Cignoni P.
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.Source: Computer graphics forum (Print) 27 (2008): 291–300. doi:10.1111/j.1467-8659.2008.01126.x
DOI: 10.1111/j.1467-8659.2008.01126.x
Project(s): EPOCH
Metrics:
Corsini M., Callieri M., Cignoni P.
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.Source: Computer graphics forum (Print) 27 (2008): 291–300. doi:10.1111/j.1467-8659.2008.01126.x
DOI: 10.1111/j.1467-8659.2008.01126.x
Project(s): EPOCH
Metrics:
See at:
www3.interscience.wiley.com | CNR ExploRA
2009
Journal article
Restricted
Image-to-geometry registration: a mutual information method exploiting illumination-related geometric properties
Corsini M., Dellepiane M., Ponchio F., Scopigno R.
This work concerns a novel study in the field of image-to-geometry registration. Our approach takes inspiration from medical imaging, in particular from multi-modal image registration. Most of the algorithms developed in this domain, where the images to register come from different sensors (CT, X-ray, PET), are based on Mutual Information, a statistical measure of non-linear correlation between two data sources. The main idea is to use mutual information as a similarity measure between the image to be registered and renderings of the model geometry, in order to drive the registration in an iterative optimization framework. We demonstrate that some illuminationrelated geometric properties, such as surface normals, ambient occlusion and reflection directions can be used for this purpose. After a comprehensive analysis of such properties we propose a way to combine these sources of information in order to improve the performance of our automatic registration algorithm. The proposed approach can robustly cover a wide range of real cases and can be easily extended.Source: Computer graphics forum (Print) 28 (2009): 1755–1764. doi:10.1111/j.1467-8659.2009.01552.x
DOI: 10.1111/j.1467-8659.2009.01552.x
Metrics:
Corsini M., Dellepiane M., Ponchio F., Scopigno R.
This work concerns a novel study in the field of image-to-geometry registration. Our approach takes inspiration from medical imaging, in particular from multi-modal image registration. Most of the algorithms developed in this domain, where the images to register come from different sensors (CT, X-ray, PET), are based on Mutual Information, a statistical measure of non-linear correlation between two data sources. The main idea is to use mutual information as a similarity measure between the image to be registered and renderings of the model geometry, in order to drive the registration in an iterative optimization framework. We demonstrate that some illuminationrelated geometric properties, such as surface normals, ambient occlusion and reflection directions can be used for this purpose. After a comprehensive analysis of such properties we propose a way to combine these sources of information in order to improve the performance of our automatic registration algorithm. The proposed approach can robustly cover a wide range of real cases and can be easily extended.Source: Computer graphics forum (Print) 28 (2009): 1755–1764. doi:10.1111/j.1467-8659.2009.01552.x
DOI: 10.1111/j.1467-8659.2009.01552.x
Metrics:
See at:
Computer Graphics Forum | onlinelibrary.wiley.com | CNR ExploRA
2008
Journal article
Open Access
MeshLab: an open-source 3D mesh processing system
Cignoni P., Corsini M., Ranzuglia G.
MeshLab is a free and open-source general-purpose mesh processing system designed to assist in the management of not-so-small, unstructured 3D models that typically occur in the pipeline when processing 3D scanned data in the context of Cultural Heritage. MeshLab provides a set of tools for editing, cleaning, healing, inspecting, rendering and converting the resulting meshesSource: ERCIM news 73 (2008): 45–46.
Project(s): EPOCH
Cignoni P., Corsini M., Ranzuglia G.
MeshLab is a free and open-source general-purpose mesh processing system designed to assist in the management of not-so-small, unstructured 3D models that typically occur in the pipeline when processing 3D scanned data in the context of Cultural Heritage. MeshLab provides a set of tools for editing, cleaning, healing, inspecting, rendering and converting the resulting meshesSource: ERCIM news 73 (2008): 45–46.
Project(s): EPOCH
See at:
ercim-news.ercim.eu | CNR ExploRA
2009
Journal article
Open Access
Scanner 3D con hardware low cost e strumenti free/open source
Callieri M., Corsini M., Ranzuglia G., Cignoni P.
3D scanning technologies offer a lot of interesting possibilities in the Cultural Heritage. Unfortunately most of the current 3D scanning solutions has an high cost and need a significant budget investment, both in terms of software and hardware. This paper will discuss how perform 3D scanning acquisition of Cultural heritage objects using only low cost hardware and open source or free software tools.Source: Archeologia e calcolatori 2 (2009): 175–182.
Callieri M., Corsini M., Ranzuglia G., Cignoni P.
3D scanning technologies offer a lot of interesting possibilities in the Cultural Heritage. Unfortunately most of the current 3D scanning solutions has an high cost and need a significant budget investment, both in terms of software and hardware. This paper will discuss how perform 3D scanning acquisition of Cultural heritage objects using only low cost hardware and open source or free software tools.Source: Archeologia e calcolatori 2 (2009): 175–182.
See at:
www.progettocaere.rm.cnr.it | CNR ExploRA
2010
Journal article
Restricted
Dynamic shading enhancement for reflectance transformation imaging
Palma G., Corsini M., Cignoni P., Scopigno R., Mudge M.
We propose a set of dynamic shading enhancement techniques for improving the perception of details, features, and overall shape characteristics from images created with Reflectance Transformation Imaging (RTI) techniques. Selection of these perceptual enhancement filters can significantly improve the user's ability to interactively inspect the content of 2D RTI media by zooming, panning, and changing the illumination direction. In particular, we present two groups of strategies for RTI image enhancement based on two main ideas: exploiting the unsharp masking methodology in the RTI-specific context; and locally optimizing the incident light direction for improved RTI image sharpness and illumination of surface features. The Result section will present a number of datasets and compare them with existing techniques.Source: ACM journal on computing and cultural heritage (Print) 3 (2010): 1–20. doi:10.1145/1841317.1841321
DOI: 10.1145/1841317.1841321
Metrics:
Palma G., Corsini M., Cignoni P., Scopigno R., Mudge M.
We propose a set of dynamic shading enhancement techniques for improving the perception of details, features, and overall shape characteristics from images created with Reflectance Transformation Imaging (RTI) techniques. Selection of these perceptual enhancement filters can significantly improve the user's ability to interactively inspect the content of 2D RTI media by zooming, panning, and changing the illumination direction. In particular, we present two groups of strategies for RTI image enhancement based on two main ideas: exploiting the unsharp masking methodology in the RTI-specific context; and locally optimizing the incident light direction for improved RTI image sharpness and illumination of surface features. The Result section will present a number of datasets and compare them with existing techniques.Source: ACM journal on computing and cultural heritage (Print) 3 (2010): 1–20. doi:10.1145/1841317.1841321
DOI: 10.1145/1841317.1841321
Metrics:
See at:
Journal on Computing and Cultural Heritage | CNR ExploRA