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A Practical Reflectance Transformation Imaging Pipeline for Surface Characterization in Cultural Heritage

Irina Ciortan, Ruggero Pintus, Giacomo Marchioro, Claudia Daffara, Andrea Giachetti, and Enrico Gobbetti

October 2016

Abstract

We present a practical acquisition and processing pipeline to characterize the surface structure of cultural heritage objects. Using a free-form Reflectance Transformation Imaging (RTI) approach, we acquire multiple digital photographs of the studied object shot from a stationary camera. In each photograph, a light is freely positioned around the object in order to cover a wide variety of illumination directions. Multiple reflective spheres and white Lambertian surfaces are added to the scene to automatically recover light positions and to compensate for non-uniform illumination. An estimation of geometry and reflectance parameters (e.g., albedo, normals, polynomial texture maps coefficients) is then performed to locally characterize surface properties. The resulting object description is stable and representative enough of surface features to reliably provide a characterization of measured surfaces. We validate our approach by comparing RTI-acquired data with data acquired with a high-resolution microprofilometer.

Reference and download information

Irina Ciortan, Ruggero Pintus, Giacomo Marchioro, Claudia Daffara, Andrea Giachetti, and Enrico Gobbetti. A Practical Reflectance Transformation Imaging Pipeline for Surface Characterization in Cultural Heritage. In The 13th Eurographics Worhshop on Graphics and Cultural Heritage, October 2016. http://dx.doi.org/10.2312/gch.20161396.

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Bibtex citation record

@InProceedings{Ciortan:2016:PRT,
    author = {Irina Ciortan and Ruggero Pintus and Giacomo Marchioro and Claudia Daffara and Andrea Giachetti and Enrico Gobbetti},
    title = {A Practical Reflectance Transformation Imaging Pipeline for Surface Characterization in Cultural Heritage},
    booktitle = {The 13th Eurographics Worhshop on Graphics and Cultural Heritage},
    month = {October},
    year = {2016},
    abstract = { We present a practical acquisition and processing pipeline to characterize the surface structure of cultural heritage objects. Using a free-form Reflectance Transformation Imaging (RTI) approach, we acquire multiple digital photographs of the studied object shot from a stationary camera. In each photograph, a light is freely positioned around the object in order to cover a wide variety of illumination directions. Multiple reflective spheres and white Lambertian surfaces are added to the scene to automatically recover light positions and to compensate for non-uniform illumination. An estimation of geometry and reflectance parameters (e.g., albedo, normals, polynomial texture maps coefficients) is then performed to locally characterize surface properties. The resulting object description is stable and representative enough of surface features to reliably provide a characterization of measured surfaces. We validate our approach by comparing RTI-acquired data with data acquired with a high-resolution microprofilometer. },
    url = {http://vic.crs4.it/vic/cgi-bin/bib-page.cgi?id='Ciortan:2016:PRT'},
}