Nowadays, photographs are one of the most used media for communication. Images are used for the representation
of documents, Cultural goods, and so on: they are used to pass on a wedge of historical memory of the society.
Since its origin, the photographic technique has got several improvements; nevertheless, photos are liable to
several damages, both concerning the physical support and concerning the colors and figures which are depicted
in it: for example, think about scratches or rips happened to a photo, or think about the fading or red (or yellow)
toning concerning the colors of a photo. In this paper, we propose a novel method which is able to assess the original beauty of digital reproductions of aged photos, as well as digital reproductions of faded goods. The method is based on the comparison of the degraded image with a not-degraded one showing similar contents; thus, the colors of the not-degraded image can be transplanted in the degraded one. The key idea is a dualism between the analytical mechanics and the color theory: for each of the degraded and not-degraded images we compute first a scatter plot of the x and y normalized coordinates of their colors; these scatter diagrams can be regarded as a system of point masses, thus provided of inertia axes and an inertia ellipsoid. Moving the scatter diagram of the degraded image over the one belonging to the not-degraded image, the colors of the degraded image can be restored.
In this contribution we describe the modern 2D and 3D technologies for the documentation, analysis and restoration of
paintings. RGB color imaging, IR and UV fluorescence sensors, together with highly precise active sensors are among
the most widely technologies in this field. The devices provide information on the painting's materials, on the employed
technique and on the conservation's state of the art work. However, all information must be correctly registered to be
able to draw safe conclusions and perform the most adequate conservation interventions. We also present a complete
example where multispectral visible images, IR reflectography, UV fluorescence and 3D data are acquired and then
combined, showing how the integration gives a new and significant improvement in the analysis of painting.
The goal of this paper is to present the research that has been carried out over the last 10 years in the Image Processing and Communications Lab of the University of Florence for developing applications for the cultural heritage field. In particular research has focused on the following issues: high resolution acquisition of paintings by means of mosaicing techniques, colour calibration of the acquisition devices, tools for forecasting the results of restoration processes (in particular with reference to the cleaning process), systems for producing virtually restored digital copies of paintings (in particular for filling in cracks and lacunas). The problems related to the distribution of the digital copies have also been considered, in particular with reference to the watermarking of
the images for copyright protection. The methodologies developed by the Lab with reference to the above mentioned issues will be described, and the main results discussed.
Over the past years the progresses of electronic imaging have encouraged researchers to develop applications for the fine arts sector. In particular the aspects that have been mostly investigated have regarded, the high quality acquisition of paintings (both from the point of view of spatial resolution and of color calibration), the actual restoration of the works (for giving to restorers an aid to forecast the results of the tasks they choose), the virtual restoration (to try to build a digital copy of the painting as it was at the origin), and the diagnosis (to automatically highlights, evaluate and monitor the possible damages that a work has suffered). Partially related to image processing are also the technologies for 3D acquisition and modeling of statues. Finally particular care has been given recently also to the distribution of the digital copies of cultural heritage objects over the Internet, thus posing novel
problems regarding the effective browsing of digital multimedia archives, and the protection of the Intellectual Property connected to art-works reproductions. The goal of this paper is to review the research results that have been obtained in the past in this field, and to present some problems that are still open and can represent a challenging research field for the future.