Automatic production of tactile graphics from scalable vector graphics

This paper presents a method to convert vector graphics into tactile representations for the blind. Generating tactile pictures from vector graphics is an important effort to bring more accessibility to the WWW as well as other means of communications since vector graphics are an increasing trend in web based graphics. Prior research has investigated methods that extracts object boundaries from images to produce raised-line tactile pictures. The proposed method extends this idea for vector graphics, producing tactile pictures where important outlines are emphasized. Important outlines are determined by using the hierarchical structure of a vector graphic. A Braille printer is used where raised dots are embossed for the outlining boundaries. Important and detail boundaries are embossed with dots of larger and smaller height, respectively, while all other regions contain no raised dots. Results testing a person's ability to discriminate, identify, and comprehend tactile pictures shows the proposed methods' advantage over two other methods.