Abstract
Extracting rail loci and estimating track shapes from a railway picture are basic problems in applying image processing to railways, such as steering control in accordance with curvature, and guard watch on running ways. We proposed a new operator to extract the loci reflecting the figures of rails according to the position and direction of locus. A trace method is applied to the result of operator processing, in which rail loci are extracted as fractional straight lines using the Hough transformation in each divided zone. Three steps of process are introduced to decide three-dimensional track shapes. In the first step, the direction of the locus is estimated by the restrict conditions of parallel rails. The direction of a cross tie is decided in the second step based on the condition of the given superelevation, and finally the distance between the rail and the camera to take the picture is estimated in the last step from the gauge between the rails in the picture. Applying this method to real images, we have confirmed feasibility of this method.
