ShadowCam: Real-Time Detection of Moving Obstacles Behind A Corner For Autonomous Vehicles

Moving obstacles occluded by corners are a potential source for collisions in mobile robotics applications such as autonomous vehicles. In this paper, we address the problem of anticipating such collisions by proposing a vision-based detection algorithm for obstacles which are outside of a vehicle's direct line of sight. Our method detects shadows of obstacles hidden around corners and automatically classifies these unseen obstacles as “dynamic” or “static”. We evaluate our proposed detection algorithm on real-world corners and a large variety of simulated environments to assess generalizability in different challenging surface and lighting conditions. The mean classification accuracy on simulated data is around 80% and on real-world corners approximately 70%. Additionally, we integrate our detection system on a full-scale autonomous wheelchair and demonstrate its feasibility as an additional safety mechanism through real-world experiments. We release our real-time-capable implementation of the proposed ShadowCam algorithm and the dataset containing simulated and real-world data under an open-source license.

[1]  Edwin Olson,et al.  AprilTag 2: Efficient and robust fiducial detection , 2016, 2016 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS).

[2]  Robert Henderson,et al.  Detection and tracking of moving objects hidden from view , 2015, Nature Photonics.

[3]  Edwin Olson,et al.  AprilTag: A robust and flexible visual fiducial system , 2011, 2011 IEEE International Conference on Robotics and Automation.

[4]  Alessandro Leone,et al.  Shadow detection for moving objects based on texture analysis , 2007, Pattern Recognit..

[5]  Cheng Lu,et al.  Entropy Minimization for Shadow Removal , 2009, International Journal of Computer Vision.

[6]  Martin Laurenzis,et al.  Dual-mode optical sensing: three-dimensional imaging and seeing around a corner , 2016 .

[7]  Rishi Ramakrishnan,et al.  Shadow compensation for outdoor perception , 2015, 2015 IEEE International Conference on Robotics and Automation (ICRA).

[8]  Xiaogang Wang,et al.  A discriminative deep model for pedestrian detection with occlusion handling , 2012, 2012 IEEE Conference on Computer Vision and Pattern Recognition.

[9]  Ramesh Raskar,et al.  Occluded Imaging with Time-of-Flight Sensors , 2016, ACM Trans. Graph..

[10]  Soon Yim Tan,et al.  Non-Line-of-Sight Localization in Multipath Environments , 2008, IEEE Transactions on Mobile Computing.

[11]  Ramesh Raskar,et al.  Estimating Motion and size of moving non-line-of-sight objects in cluttered environments , 2011, CVPR 2011.

[12]  Alex Zelinsky,et al.  Learning OpenCV---Computer Vision with the OpenCV Library (Bradski, G.R. et al.; 2008)[On the Shelf] , 2009, IEEE Robotics & Automation Magazine.

[13]  Mohammed Bennamoun,et al.  Automatic Shadow Detection and Removal from a Single Image , 2016, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[14]  Jason J. Corso,et al.  A Continuous Occlusion Model for Road Scene Understanding , 2016, 2016 IEEE Conference on Computer Vision and Pattern Recognition (CVPR).

[15]  Koen E. A. van de Sande,et al.  Evaluating Color Descriptors for Object and Scene Recognition , 2010, IEEE Transactions on Pattern Analysis and Machine Intelligence.

[16]  Peter I. Corke,et al.  Dealing with shadows: Capturing intrinsic scene appearance for image-based outdoor localisation , 2013, 2013 IEEE/RSJ International Conference on Intelligent Robots and Systems.

[17]  Mohan M. Trivedi,et al.  Learning to Detect Vehicles by Clustering Appearance Patterns , 2015, IEEE Transactions on Intelligent Transportation Systems.

[18]  Fadel Adib,et al.  See through walls with WiFi! , 2013, SIGCOMM.

[19]  Javier Alonso-Mora,et al.  Foresight: Remote Sensing for Autonomous Vehicles Using a Small Unmanned Aerial Vehicle , 2017, FSR.

[20]  Jing Wu,et al.  Adaptive fuzzy filter algorithm for real-time video denoising , 2008, 2008 9th International Conference on Signal Processing.

[21]  Vivek K Goyal,et al.  Photon-efficient imaging with a single-photon camera , 2016, Nature Communications.

[22]  Paul Newman,et al.  LAPS-II: 6-DoF day and night visual localisation with prior 3D structure for autonomous road vehicles , 2014, 2014 IEEE Intelligent Vehicles Symposium Proceedings.

[23]  Frédo Durand,et al.  Turning Corners into Cameras: Principles and Methods , 2017, 2017 IEEE International Conference on Computer Vision (ICCV).

[24]  Vivek K. Goyal,et al.  Photon-Efficient Computational 3-D and Reflectivity Imaging With Single-Photon Detectors , 2014, IEEE Transactions on Computational Imaging.

[25]  Hans-Hellmut Nagel,et al.  Tracking of Occluded Vehicles in Traffic Scenes , 1996, ECCV.

[26]  Javier Alonso-Mora,et al.  A parallel autonomy research platform , 2017, 2017 IEEE Intelligent Vehicles Symposium (IV).