ATTEMPTS TO AUTOMATE THE PROCESS OF GENERATION OF ORTHOIMAGES OF OBJECTS OF CULTURAL HERITAGE
- Faculty of Geodesy and Cartography, Institute of Photogrammetry, Remote Sensing and Spatial Information Systems, Warsaw, University of Technology, Warsaw, Poland
Keywords: high resolution orthoimages, Hough algorithm, automatic image orientation, SIFT, orthorectification
Abstract. At present, digital documentation recorded in the form of raster or vector files is the obligatory way of inventorying historical objects. The orthoimage is a cartometric form of photographic presentation of information in the two-dimensional reference system. The paper will discuss the issue of automation of the orthoimage generation basing on the TLS data and digital images. At present attempts are made to apply modern technologies not only for the needs of surveys, but also during the data processing. This paper will present attempts aiming at utilisation of appropriate algorithms and the author’s application for automatic generation of the projection plane, for the needs of acquisition of intensity orthoimages from the TLS data. Such planes are defined manually in the majority of popular TLS data processing applications. A separate issue related to the RGB image generation is the orientation of digital images in relation to scans. It is important, in particular in such cases when scans and photographs are not taken simultaneously. This paper will present experiments concerning the utilisation of the SIFT algorithm for automatic matching of intensity orthoimages of the intensity and digital (RGB) photographs. Satisfactory results of the process of automation, as well as in relation to the quality of resulting orthoimages have been obtained.