luigi barazzetti | Politecnico di Milano (original) (raw)

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Papers by luigi barazzetti

Currently, the commercial market offers several tools for digital documentation of historic sites... more Currently, the commercial market offers several tools for digital documentation of historic sites and buildings. Photogrammetry and laser scanning play a fundamental role in the acquisition of metric information, which is then processed to generate reliable records particularly useful also in the built heritage conservation field. Although potentially very fast and accurate, such techniques require expert operators to produce reliable results, especially in the case of complex and large sites. The aim of this paper is to present the digital workflow developed for data acquisition and processing of the Shaikh Isa Bin Ali house in Muharraq, Bahrain. This historic structure is an outstanding example of Bahrain architecture as well as tangible memory of the country history, with strong connotations in the Bahrain cultural identity. The building has been documented employing several digital techniques, including: aerial (drone) and terrestrial photogrammetry, rectifying photography, total station and laser scanning. The documentation project has been developed for the Bahrain Authority for Culture and Antiquities (BACA) by a multidisciplinary team of experts from Carleton Immersive Media Studio (CIMS, Carleton University, Canada) and Gicarus Lab (Politecnico di Milano, Italy).

ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences

Documenting the physical characteristics of historic structures is the first step for any prevent... more Documenting the physical characteristics of historic structures is the first step for any preventive maintenance, monitoring, conservation, planning and promotion action. Metric documentation supports informative decision-making process for property owners, site managers, public officials, and conservators. This information serves also a broader purpose, over time, it becomes the primary means by which scholars, heritage professionals, and the general public understand a site that radically changed or disappeared. Further, documentation supports monitoring as well as the character-defining elements analysis, relevant to define the values of the building for the local and international community. The awareness of these concepts oriented the digital documentation and training activities, developed between 2016 and 2017, for the Bahrain Authority for Culture and Antiquities (BACA) in Bahrain. The developed activities had two main aims: a) support the local staff in using specific recor...

Lecture Notes in Computer Science, 2016

The goal of this study was to analyze the filtering performance of LiDAR data of an algorithm imp... more The goal of this study was to analyze the filtering performance of LiDAR data of an algorithm implemented by our group of research. The algorithm is completely automatic and needs only the raw data classified as first and last pulses. It was implemented in the open source software GRASS and it is composed of three functions that have to be

Fourth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2016), 2016

Radiometric image normalization is one of the basic pre-processing methods used in satellite time... more Radiometric image normalization is one of the basic pre-processing methods used in satellite time series analysis. This paper presents a new multi-image approach able to estimate the parameters of relative radiometric normalization through a multiple and simultaneous regression with a dataset of a generic number of images. The method was developed to overcome the typical drawbacks of standard one-to-one techniques, where image pairs are independently processed. The proposed solution is based on multi-image pseudo-invariant features incorporated into a unique regression solved via Least Squares. Results for both simulated and real data are presented and discussed.

Advanced Engineering Informatics, 2016

Proceedings of the 33rd Computer Graphics International on - CGI '16, 2016

Proceedings of Spie the International Society For Optical Engineering, Aug 1, 2009

Nowadays commercial software able to automatically create an accurate 3D model from any sequence ... more Nowadays commercial software able to automatically create an accurate 3D model from any sequence of terrestrial images is not available. This paper presents a methodology which is capable of processing markerless block of terrestrial digital images to perform a twofold task: (i) determine the exterior orientation parameters by using a progressive robust feature-based matching followed by a Least Squares Matching refining and a bundle adjustment; (ii) extract a dense point-clouds by using a multi-image matching based on diverse image primitives. The final result is an accurate surface model with characteristics similar to those achievable with range-based sensors. In the whole processing workflow the natural texture of the object is used, thus images and calibration parameters are the only inputs. The method exploits Computer Vision and Photogrammetric techniques and combines their advantages in order to automate the process. At the same time it ensures a precise and reliable solution. To verify the accuracy of the developed methodology, several comparisons with manual measurements, total station data and 3D laser scanner were also carried out.

Proceedings of the First International Conference on Human Computer Interaction Tourism and Cultural Heritage, Sep 7, 2010

It is normal for tourists to take photos during their holidays, which are then printed, loaded in... more It is normal for tourists to take photos during their holidays, which are then printed, loaded into digital frames or shared on the Internet. This paper describes a new methodology to obtain accurate 3D digital models and material replicas of real objects, starting from digital images acquired with consumer and professional cameras. The implemented software is completely automatic and provides detailed reconstructions. It stands out from other existing approaches for the high metric accuracy of the final product, the level of detail obtainable, the speed of the algorithms and its adaptability under different viewing conditions. Several examples relating to an actual trip to Rome are reported and discussed, showing what a tourist can obtain with this package. Obviously, the method can be used for many other applications in which accurate models are needed.

The article presents a powerful and automated methodology to extract accurate image correspondenc... more The article presents a powerful and automated methodology to extract accurate image correspondences from different kinds of closerange image blocks for their successive orientation with a bundle adjustment. The actual absence of a commercial solution able to automatically orient markerless image blocks confirms the still open research in this field. The developed procedure combines different image processing algorithms and robust estimation methods in order to obtain accurate locations and a uniform distribution of tie points in the images. We demonstrate the capabilities and effectiveness of this method with several tests on closed or open sequences and sparse blocks of images captured by a standard frame (pinhole) camera, but also spherical images. An accuracy evaluation of the achieved 3D object coordinates with photogrammetric bundle techniques is also presented. Figure 1. Typical sequence (92 images) automatically oriented extracting the necessary image correspondences (18,500 3D points).

Photogrammetric Engineering & Remote Sensing, 2016

International Journal of Heritage in the Digital Era, 2015

2015 IEEE International Geoscience and Remote Sensing Symposium (IGARSS), 2015

This paper wants to explore the application of the theory of reliability, which has become largel... more This paper wants to explore the application of the theory of reliability, which has become largely popular in the analysis of geodetic and photogrammetric networks, to the multiple co-registration of satellite time-series of images through block adjustment. Indeed the current and future availability of long series of satellite imagery can be exploited for the purpose of change detection and soil monitoring along time. Due to the large overlap between images, the multiple coregistration is a feasible task that may result in an increased reliability of the observations. On the other hand, to deal with such big data sets, automatic procedures have been developed for co-registration of satellite time-series. Due to the presence of residual errors in such procedures, the error analysis during the final block adjustment plays a key-role. Consequently, the background on the theory of reliability has been introduced here, and three simulated examples have been created in order to check the efficiency of the reliability analysis when dealing with time-series of medium resolution satellite imagery.

Third International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2015), 2015

Image sequence analysis for 3-D modeling is an aim of primary importance in Photogrammetry and Co... more Image sequence analysis for 3-D modeling is an aim of primary importance in Photogrammetry and Computer Vision. Both disciplines approach this issue, but with different procedures. The result is the reconstruction of a 3-D model of the captured object featuring different characteristics in terms of accuracy and time needed to built it up. The goal of this work is the

My �� Sn Sanctuary comprehends several ancient Hindu temples and is the most foremost heritage si... more My �� Sn Sanctuary comprehends several ancient Hindu temples and is the most foremost heritage site of this nature in Vietnam. Part of the complex is today seriously damaged and needs restoration works. The temple G1 addressed in this work represents a pilot case to establish a workflow for both documentation and conservation purposes. Both aims required as primary need