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Real-Time Sidewalk Slope Calculation through Integration of GPS Trajectory and Image Data to Assist People with Disabilities in Navigation

School of Information Sciences, University of Pittsburgh, 135 North Bellefield Avenue, Pittsburgh, PA 15260, USA
Author to whom correspondence should be addressed.
Academic Editors: Stephan Winter, Alper Yilmaz, Monika Sester and Wolfgang Kainz
ISPRS Int. J. Geo-Inf. 2015, 4(2), 741-753;
Received: 31 January 2015 / Revised: 14 April 2015 / Accepted: 27 April 2015 / Published: 4 May 2015
(This article belongs to the Special Issue Selected Papers from the ISPRS Tracking and Imaging Challenge 2014)
PDF [2342 KB, uploaded 20 May 2015]


People with disabilities face many obstacles in everyday outdoor travels. One of the most notable obstacles is steep slope on sidewalk segments. Current navigation systems/services do not all support map databases with slope attributes and cannot calculate sidewalk slope in real time. In this paper, we present a technique for calculating slopes of sidewalk segments by image data and predict the most suitable route for each individual user through integration with GPS trajectory. In our technique we make use of GPS trajectory data, to identify the sidewalk segment on which the traveler will most probably pass, and images of the identified sidewalk segment. Through edge detection techniques we detect edges of objects, such as buildings, billboards, and walls, in the background. Slope of the segment is then calculated by comparing its line representation in the map with the detected edges. Our experiment result indicates effective calculation of sidewalk slopes. View Full-Text
Keywords: GPS trajectory; image processing; navigation GPS trajectory; image processing; navigation

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This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

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Lu, Y.; Karimi, H.A. Real-Time Sidewalk Slope Calculation through Integration of GPS Trajectory and Image Data to Assist People with Disabilities in Navigation. ISPRS Int. J. Geo-Inf. 2015, 4, 741-753.

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