Revista Brasileira de Cartografia (Apr 2006)
Verificação Automática da Malha Viária Georreferenciada em Imagens Digitais
Abstract
This paper proposes a solution for the problem of automatic verification of georeferenced road network in digital aerial images. The proposed methodology is based on two basic stages, i.e.: 1- Automatic extraction of georeferenced roads; and 2- Consistence analysis of extracted roads. In the first stage, a road extraction methodology based on the dynamic programming algorithm is used to automatically extract georeferenced roads. The extraction methodology is initialized with a few points automatically measured along the georeferenced road network and projected into the image-space. The precision of the projected points is also computed, making possible the automatic computation of the search windows used by the dynamic programming algorithm. In the second stage, the consistency analysis aims at checking the compatibility between the extracted roads and the corresponding georeferenced roads projected into the image-space. The checking criterion is based on an error model that basically embodies the uncertainties of the georeferenced roads. The obtained results have shown that the proposed methodology is promising, as it can automatize the most part of arduous and time-consuming road network verification task, leaving only a little part to be complimented by an operator. It was also shown that the methodology has the potential to be used in applications like the georeferenced road network's systematic error correction and geometric refinement.