Grouping contents on Korean road signs

In this paper, we propose a method for grouping the content of Korean road signs into the five categories of Korean, English, direction symbol, road symbol and distance digit. The first step necessary to automate the inspection of road signs is to determine whether their content is reproduced as clearly as in the original design. Previously, inspections were performed manually by humans. Instead, we deal with images that are acquired manually by digital cameras, using various features including color, relative length and size, reflecting the design rule for Korean road sign. We began by analyzing blobs that are obtained through connected component analysis after binarization. These are first grouped into two categories: direction symbol and size. Then, the road symbol is selected using color. Finally, the remaining blobs are grouped using the relative length between blobs. Experimental results using real images show the feasibility of the proposed algorithm.