Abstract
Road signs provide important information to guide and regulate the behavior of drivers and pedestrians to make their journeys safer and more comfortable. Therefore, we have already proposed a method for extracting and recognizing circular road signs on the basis of the color information and shape features derived from a color scene image. In the previous method, the use of lightness in images and the determination of a dynamic threshold for the binary processes have not been achieved yet. This paper proposes an algorithm to extract circular road signs on the basis of features of scene images. That is, the proposed method makes good use of lightness as well as hue and chroma. Also, the thresholds regarding the chroma and lightness in each binary process of the blue road signs are able to be automatically decided using local features in the target image. Tests on 295 images suggest that the proposed method can accurately extract circular road signs.
