Restauración de cartografía antigua mediante procesado de imagen. Producción Ortofotografía Histórica

Abstract

Since the middle of the last century, public administrations have been conducting photographic flights in order to meet the needs of a variety of different departments. The great value of such documentation is safeguarded and supported by a number of regional and national projects such as the PNOA (National plan of Aerial Orthophotography) Historical Project The aim of this project was to develop a methodology for the production of orthophotographs based on historical photographs using the latest photogrammetric tools in order to minimize the personnel involved in the manual phases of the project as well as to reduce production times. There have been several tests of new photogrammetric tools based mainly on techniques such as SFM (structure from motion), with its origins in computer vision, creating new possibilities to streamline the production process as a whole. Commercial tools like Smart3D capture, 3D flow, Autodesk 123D, Photoscan Pro, Pix4d, in addition to free software tools like Bundler, VisualSFM, OpenCV orMatlab libraries allow for the acceleration of the production process in the relative orientation phase. However, the problem of manual identification of control points in order to control points in order to control all of the variables of an adjustment block, camera aberrations, film deformation and scanning, among others, still remain. Thanks to the digital processing of existing historical cartographic products generated from photogrammetric flights using orthorectified lenses, the task of identifying checkpoints in current cartographic products of higher resolution are provided which help determine the calibration parameters of unknown cameras. Using this methodology, our intention is to initiate an ambitious project in order