<p><strong>Abstract.</strong> This involved a sort of preventive diagnostics based on the historical knowledge of the building, on the construction techniques and on the compositional style, on the other hand on diagnostic imaging using photographic techniques developed from the early 1800s.<br />The preliminary cognitive approach, the stylistic identification, the classification of method, the historical reading, the critical analysis of the historical and compositional genesis of the building, the careful reading of the pathogenesis in progress, mark, from the mid-800 in then, the evolution of the concept of restoration that will take shape from time to time from what was "before" and only secondarily from what "is now". This perhaps unconscious diagnostic reading of the artifact (first artistic, then monumental and finally as a cultural testimony) has, in fact, involved generations of restorers painting the landscape of the restoration sometimes in different way, with results that well we know.<br />In fact, almost never the fathers of restoration (or anti-restoration) explicitly touch the issues of preventive diagnosis, but certainly base their theories and their "restoration" on the observation of the factory, on the knowledge of construction techniques and historical period of belonging.</p><p>The things begin to change starting from the first Charter of Restoration of 1883 with the enlargement of the diagnostic project (which finds paternity starting from the 1972 Italian Charter, which embraces many disciplines: from photography to relief, from chemistry to physics, from the historical reading to the knowledge of the materials, from the identification of the material pathogenesis to the reading of the static and structural framework of the buildings.<br />With the passing of time and the explosion of science and technology in the field of cultural heritage all aspects related to preliminary knowledge aimed at their conservation evolve exponentially especially with the advent of electronics. Starting from the 60s of the 1900s, equipment with great calculation capacity and small dimensions was born, a real springboard for the new techniques of surveying by means of a laser scanner, photographic socket and photogrammetric restitution.<br />Tools and techniques of restitution settle and even more solidly base the knowledge base linked to the project of conservation and enhancement of cultural heritage.</p><p>Base of support and extraction of selected data and / or dedicated to the project continuously interface with the disciplines of knowledge that are now more and more "forced" to the table of confrontation to reveal information hidden in the folds of time.<br />A recent work on an eighteenth-century Sanremese building it gives us information on the complexity of the construction of a process of knowledge articulated, composed of several activities to be correlated and integrated continuously, one in the other to try to give answers on evident problems of degradation never fully documented.</p><p>The study, performed in a rather limited time frame, focused on the Hall of family portraits seriously degraded by "accidents of various kinds". The work was based on the three-dimensional conception of the acquired data, allowing to investigate the hall as an articulated organism, supporting the technicians in the three-dimensional understanding of the asset, constituting a complete database of the actual state, becoming support of the results of the various surveys conducted for the knowledge of the asset.<br />In this cognitive path, the BIM method is understood as the possibility of constructing the "as built" model, complete not only of the dimensional graphic data of the asset, but also of those that contribute to the determination of the actual state. The graphic aspect of the model must be connected with historical, material, degradation, contextual information, with the results of any specialized investigations conducted.<br />Only then will the BIM model of a historic building be the complete database, the "medical record" of its state of health, complete with diagnosis, care, indications of maintenance that can be shared and questioned over time.</p>
Remote Colorimetric and Structural Diagnosis by RGB-ITR Color Laser Scanner Prototype