Caracterização da densidade das lacunas em superfícies pictóricas com recurso a Sistemas de Informação Geográfica (SIG)

This study deals with the application of simple image-processing techniques, in environment of geographic information system (GIS), on a detailed digital photography of a retabular painting. The aim is to register the lacunae density in a semi-automatic way, through a method of reclassification, like thresholding, and an algorithm of Kernel density estimation (Parzen-Rozenblatt method). The digital photography image used on exercise shows a detail of a 16th century panel painting, named “Resurrection of Lazarus”, from the Rotunda of Christ Convent, in Tomar, Portugal. The final result is a thematic pathologies map of lacunae type.