Smartphone-Based Obstacle Detection for the Visually Impaired

Abstract

Abstract.One of the main problems that visually impaired people have to deal with is moving autonomously in an unknown environment. Currently, the most used autonomous walking aid is still the white can. Though in the last few years more technological devices have been introduced, referred to as electronic travel aids (ETAs). In this paper, we present a novel ETA based on computer vision. Exploiting the hardware and software facilities of a standard smartphone, our system is able to extract a 3D representation of the scene and detect possible obstacles. To achieve such a result, images are captured by the smartphone camera and processed with a modified Structure from Motion algorithm that takes as input also information from the built-in gyroscope. Then the system estimates the ground-plane and labels as obstacles all the structures above it. Results on indoor and outdoor test sequences show the effectiveness of the proposed method.

Review of Navigation Assistive Tools and Technologies for the Visually Impaired

“…Another mobile camera-based navigation system for the visually impaired was proposed in [ 38 ]. This system uses pre-stored images of the floor to guide people in finding the obstacle-free route by comparing current floor images with pre-stored images and checking for introduced obstacles.…”

“…In [ 38 ], a “smart environment explorer (SEE)”-based stick system was designed and proposed for blind people. The system guides the visually impaired and helps enhance the ability for “space consciousness”.…”

A Comprehensive Examination of Electronic Wayfinding Technology for Visually Impaired Travelers in an Urban Environment

“…More recently, attention has been placed on the development of smartphone-based technologies to facilitate visually impaired users in their wayfinding activities (Coughlan and Manduchi, 2009;Kane et al, 2009;Narasimhan et al, 2009;Swobodzinski and Raubal, 2009;Zöllner et al, 2011;Ahmetovic, 2013;Hakobyan et al, 2013;Caldini et al, 2015;Diamantatos and Kavallieratou, 2014;Ye et al, 2014;Griffin-Shirley et al, 2017). A widely under-explored component in these works, however, is the empirical assessment of smartphone-based wayfinding technologies in terms of their usefulness (i.e., the degree to which a product enables a user to achieve his or her goals, which includes the user's intrinsic motivation) and usability (i.e., the degree to which a product is able or fit to be used) of these technologies (Davis, 1989) for visually impaired users, which is particularly relevant for the study at hand.…”

Assistive Systems for the Visually Impaired Based on Image Processing

“…Obstacle detection is one of the representative research themes. Many research groups have proposed obstacle detection systems based on laser sensors [3][4][5][6][7][8][9][10][11], single charge-coupled devices cameras [12][13][14][15][16], ultrasonic sensors [17][18][19][20][21][22][23][24][25][26][27][28][29], stereoscopic cameras [30][31][32][33][34][35][36][37][38][39][40][41], or RGB-D cameras [42][43][44][45][46]. These assistive systems are built on the basis of the concept of the electronic travel aid (ETA) [47,48], which aims to assist visually impaired users in walking while avoiding obstacles.…”