An extraction method of solid line graph elements in mathematical graphs for automating translation of tactile graphics

Tactile graphics are images that use raised surface so that a visually impaired person can feel them. Tactile graphics are necessary to visually impaired students when they study mathematics and science. Since producing tactile graphics are not simple task, an intelligent computer-aided system for assisting the production of tactile graphics is needed. Mathematical graph recognition from printed materials plays an important role to develop such a system. So, this paper focuses on part of a method of mathematical graph recognition. A mathematical graph includes graph elements such as the rays representing the x-axis and the y-axis and the line segments or the curves representing functions or equations. Graph elements are often drawn so that they are overlapped each other. So, this paper discusses a method for extracting graph elements from an element which is drawn by overlapping more than one graph element. The effectiveness of our method is evaluated by a computer experiment.