Heritage and technology: novel approaches to 3D documentation and communication of architectural heritage

In the past few years we have seen a drastic increasing of image-based modeling (IBM) techniques to get high quality reality-based 3D models. The low costs of these techniques as well as their attractive visual quality have lead many researchers and professionals to invest their energies and resources in several tests. The use of IMB in the field of cultural heritage is mostly exploited in applications such as documentation, digital restoration, visualization, inspection, planning, AR/VR, conservation and design. One of the strengthen of multi-view stereo techniques is the possibility to capture millions of points in a very short time and to get a 3D textured polygonal model that can be easily used for visualizing and communicating digital assets. Currently, we can distinguish between desktop and web based packages. If the first one needs a high performance computer for data processing, the second one use the power of cloud computing to carry out a semi-automatic data processing instead of considerably slowing-down the computer. The aim of this study is to compare two of the most known IBM packages (Agisoft Photoscan and Autodesk Recap) in applications dealing with architectural heritage. The comparison among the chosen packages are typical user-oriented parameters such as: visual completeness/detail of the 3D model; ratio between images resolution/number of images/time processing; number of used/discharged images (useful to optimize the images network); metric accuracy; learning curve/usability.