A Digital Investigation Manifesting use of Geometric Stencils for the Drawing of Akrotiri Thera Prehistoric Wall Paintings

The present chapter deals with the problem of determining the method used to draw several celebrated and beautiful wall-paintings belonging to the Late Bronze Age (c. 1630 B.C.), that were excavated at Akrotiri, Thera, Hellas (Greece). First, the authors process the wall paintings’ digital images in order to extract the contour of their main thematic entities. Subsequently, a number of fundamental definitions are given and the main hypothesis is stated, namely that geometrical stencils were used for the drawing of the considered wall paintings. A first estimation of the probable one stoke parts of the contour is undertaken, based on curvature considerations and minimization of corresponding error functions. Next, they select families of geometrical curves as potential prototypes of the employed stencils. The selection is based on archaeological and historical criteria. A novel exhaustive curve fitting method is introduced that offers unambiguously optimal matching of two digital curves. Taking into consideration the previous stages, the exact values of the stencils’ parameters are determined. Finally, the hypothesis that stencils were used for the drawing of the considered wall paintings is supported substantially by a visual representation of the one stroke parts together with the corresponding stencil segments that generated them.