Estimating the Distance from View Point to Yellow Tactile Tile on Platform Using an Image

Abstract

For the purpose of mobility aid for the blind, this paper presents a new method for detecting the position of yellow tactile tile along train platform curb which is one of the most dangerous drop-off, by using an image. In Japan, yellow tactile tiles are usually set along train platform curbs in order to notify the blind of danger. In the method, first, we extract the region of yellow tactile tile in an image with a perceptually uniform color system. And two edge lines of both side of yellow tactile the are detected by using the Hough transformation. Then vertical lines such as pillars are extracted using information of the width of yellow tactile tile to obtain a surface normal of a platform. Finally, the distance from the blind to the yellow tactile tile is estimated based on 3D vector analysis under the perspective projection. The effectiveness of the proposed method is shown from extensive experiments for real images of subway platform scenes.