Interactive sonification of images on mobile devices for the visually impaired

A human-computer mobile interface for visually impaired persons is presented in the article. The authors propose several methods for image analysis and sound synthesis basing on interaction with a mobile device using tactile gestures. The developed algorithms allow to sonify colour and greyscale images, but mainly focus on the presentation of abstract black and white shapes for use in education of blind children. The interaction of the sonification process is achieved through various tactile gestures depending on the sonification mode, ranging from simple point-touches to two-handed multi-touch control. Implementation and pilot test results of the proposed human-computer interface using an Android tablet is included in the article.