Road extracted from satellite imagery have been used for many different purposes, e.g. military, map publishing, transportation, and car navigations, etc. Many method such as, neural network, Knowledge-based, Optimal search, Snake model, Semantic model, Road operator model, etc. was researched to identify road from satellite image, but because of complicated characteristics of road and image itself, and automated road network extraction still remains a challenge problem, and no existing software is able to perform the task reliably. This paper presents a hybrid method which combines Fuzzy-C-Means with back-propagation neural network and knowledge processing technique to detect roads in SPOT image.
The basic idea of the paper is "easiest first" principal, and firstly focus to extract local salient road segments most easily and reliably, then use contextual knowledge and supervised back-propagation neural network model to extract fuzzy road segments among salient road segment, and then grouping these extracted pixel as seed point, candidate point, and not-road point, and then according to appropriate knowledge rule to traversal and join, guide the further road link in the whole image. At last, some post-processing steps are taken to refine the result. The resultant image shows this hybrid identification method performs better than only using knowledge-based method or neural network techniques.