Alessandro Spinetti

Bio: Alessandro Spinetti is an academic researcher from University of Florence. The author has contributed to research in topics: Radar & Ground-penetrating radar. The author has an hindex of 8, co-authored 15 publications receiving 253 citations.

Virtualizing ancient Rome: 3D acquisition and modeling of a large plaster-of-Paris model of imperial Rome

Abstract: Computer modeling through digital range images has been used for many applications, including 3D modeling of objects belonging to our cultural heritage. The scales involved range from small objects (e.g. pottery), to middle-sized works of art (statues, architectural decorations), up to very large structures (architectural and archaeological monuments). For any of these applications, suitable sensors and methodologies have been explored by different authors. The object to be modeled within this project is the "Plastico di Roma antica," a large plaster-of-Paris model of imperial Rome (16x17 meters) created in the last century. Its overall size therefore demands an acquisition approach typical of large structures, but it also is characterized extremely tiny details typical of small objects (houses are a few centimeters high; their doors, windows, etc. are smaller than 1 centimeter). This paper gives an account of the procedures followed for solving this "contradiction" and describes how a huge 3D model was acquired and generated by using a special metrology Laser Radar. The procedures for reorienting in a single reference system the huge point clouds obtained after each acquisition phase, thanks to the measurement of fixed redundant references, are described. The data set was split in smaller sub-areas 2 x 2 meters each for purposes of mesh editing. This subdivision was necessary owing to the huge number of points in each individual scan (50-60 millions). The final merge of the edited parts made it possible to create a single mesh. All these processes were made with software specifically designed for this project since no commercial package could be found that was suitable for managing such a large number of points. Preliminary models are presented. Finally, the significance of the project is discussed in terms of the overall project known as "Rome Reborn," of which the present acquisition is an important component.

Three-dimensional acquisition of large and detailed cultural heritage objects

Abstract: Cultural heritage digitization is becoming more common every day, but the applications discussed in the literature address mainly the digitization of objects at a resolution proportional to the object size, using low resolution for large artifacts such as buildings or large statues, and high resolution for small detailed objects. The case studied in this paper concerns a huge physical model of imperial Rome (16 × 17.5 m) whose extremely small details forced the use of high resolution and low noise scanning, in contrast with the long range needed. This paper gives an account of the procedures and the technologies used for solving this “contradiction”.

An ultra-wideband high-dynamic range GPR for detecting buried people after collapse of buildings

Abstract: An ultra wide band high dynamic range GPR radar - has been tested for buried victims detection. After a building collapse, for example due to an earthquake, the priority of search and rescue teams is to localize people trapped under debris. Several tools are available to help the detection of buried humans, such as micro-cameras, high sensitivity microphones, and so on. Many of these tools present some limitations such as low penetration depth and high susceptibility to external noises. In this paper the authors test the use of an Enhanced Ultra Wide Band (UWB), Continuous Wave Stepped Frequency (CW-SF) Ground penetrating radar as rescue equipment. The radar has been experimented both in controlled environment, and in a real test site, at the Fire-fighters Station of Pisa, Italy.

3D digitization of a large model of imperial Rome

Abstract: This paper describes 3D acquisition and modeling of the "Plastico di Roma antica", a large plaster-of-Paris model of imperial Rome (16/spl times/17 meters) created in the last century. Its overall size demands an acquisition approach typical of large structures, but it is also characterized by extremely tiny details, typical of small objects: houses are a few centimeters high; their doors, windows, etc. are smaller than 1 cm. The approach followed to resolve this "contradiction" is described. The result is a huge but precise 3D model created by using a special metrology laser radar. We give an account of the procedures of reorienting the large point clouds obtained after each acquisition step (50-60 million points) into a single reference system by means of measuring fixed redundant reference points. Finally we show how the data set can be properly divided into 2/spl times/2 meters sub-areas for allowing data merging and mesh editing.

Range sensors on marble surfaces: quantitative evaluation of artifacts

Abstract: While 3D imaging systems are widely available and used, clear statements about the possible influence of material properties over the acquired geometrical data are still rather few. In particular a material very often used in Cultural Heritage is marble, known to give geometrical errors with range sensor technologies and whose entity reported in the literature seems to vary considerably in the different works. In this article a deep investigation with different types of active range sensors used on four types of marble surfaces, has been performed. Two triangulation-based active sensors employing laser stripe and white light pattern projection respectively, and one PW-TOF laser scanner have been used in the experimentation. The analysis gave rather different results for the two categories of instruments. A negligible light penetration came out from the triangulation-based equipment (below 50 microns with the laser stripe and even less with the pattern projection device), while with the TOF system this came out to be two orders of magnitude larger, quantitatively evidencing a source of systematic errors that any surveyor engaged in 3D scanning of Cultural Heritage sites and objects should take into account and correct.

Heritage Recording and 3D Modeling with Photogrammetry and 3D Scanning

Abstract: The importance of landscape and heritage recording and documentation with optical remote sensing sensors is well recognized at international level. The continuous development of new sensors, data capture methodologies and multi-resolution 3D representations, contributes significantly to the digital 3D documentation, mapping, conservation and representation of landscapes and heritages and to the growth of research in this field. This article reviews the actual optical 3D measurement sensors and 3D modeling techniques, with their limitations and potentialities, requirements and specifications. Examples of 3D surveying and modeling of heritage sites and objects are also shown throughout the paper.

Recent developments in large-scale dimensional metrology

Abstract: With ever-more demanding requirements for the accurate manufacture of large components, dimensional measuring techniques are becoming progressively more sophisticated. This review describes some of the more recently developed techniques and the state-of-the-art in the more well-known large-scale dimensional metrology methods. In some cases, the techniques are described in detail, or, where relevant specialist review papers exist, these are cited as further reading. The traceability of the measurement data collected is discussed with reference to new international standards that are emerging. In some cases, hybrid measurement techniques are finding specialized applications and these are referred to where appropriate. © IMechE 2009.

Reality-based 3D documentation of natural and cultural heritage sites—techniques, problems, and examples

Abstract: The importance of cultural and natural heritage documentation is well recognized at international level, and there is an increasing pressure to document and preserve heritage also digitally. The continuous development of new sensors, data capture methodologies, and multi-resolution 3D representations and the improvement of existing ones can contribute significantly to the 3D documentation, conservation, and digital presentation of heritages and to the growth of the research in this field. The article reviews some important documentation requirements and specifications, the actual 3D surveying and modeling techniques and methodologies with their limitations and potentialities as well some visualization issues involved in the heritage field. Some examples of world heritage sites 3D documentation are reported and discussed.

Serious Games and Edutainment Applications

Abstract: The recent re-emergence of serious games as a branch of video games and as a promising frontier of education has introduced the concept of games designed for a serious purpose other than pure entertainment. To date the major applications of serious games include education and training, engineering, medicine and healthcare, military applications, city planning, production, crisis response, to name just a few. If utilised alongside, or combined with conventional training and educational approaches, serious games could provide a more powerful means of knowledge transfer in almost every application domain. Serious Games and Edutainment Applications offers an insightful introduction to the development and applications of games technologies in educational settings. It includes cutting-edge academic research and industry updates that will inform readers of current and future advances in the area. The book is suitable for both researchers and educators who are interested in using games for educational purposes, as well as game professionals requiring a thorough understanding of issues involved in the application of video games technology into educational settings. It is also applicable to programmers, game artists, and management contemplating or involved in the development of serious games for educational or training purposes.