Classification criteria for local navigation digital assistance techniques for the visually impaired

This paper presents the criteria for classification of the existing techniques for the development of navigation aid for the visually impaired people. Digital assistance for the visually impaired people to navigate easily even during the presence of static and moving obstacles has been a food for research over the years. The motivation for the current work is the development of a smart hearing aid for people with hearing loss. The filtering of essential information to enable a better sensing of the surrounding environment for people with diminished vision is the main aim of developing a navigation system for people with such impairment. The current study gives an overview of the techniques used for obstacle detection, detection of path for navigation and system for alerting the users about existing obstacles in their path. It also presents the selected algorithms used for detecting the obstacles in the path and alarming the user about its presence which offers as a criteria for the comparison of the techniques for the development of a navigation system for the blind.