Shane Tuohy

 In 2008, rear end collisions accounted for almost 25% of all injuries sustained in road traffic accidents on Irish roads [RSA Road Collision Factbook 2008]  Effective distance determination can go a long way to reducing injuries

 Mercedes Pre-Safe  Audi Pre-Sense Plus  Toyota Pre-Collision System  All are RADAR systems  Expensive  Cannot detect humans, animals  Susceptible to interference

 Front facing standard optical camera  Cheap  Many uses  Simple to install

 Begun by Intel, currently maintained by community, under stewardship of Willow Garage  Extensive library of Computer Vision functions  C, C++, Python, Java  No need to continually ‘reinvent the wheel’

Capture Image Process (OpenCV) Feedback To User

Capture Image Process (OpenCV) Feedback To User

Threshold Image Warp Perspective Determine Distance

 Remove road surface and highlight objects  Sample road surface in front of vehicle  Remove pixels ±35 of sampled value  Apply binary threshold

Threshold Image Warp Perspective Determine Distance

 Distance in image does not change linearly as vehicle changes position

 Inverse Perspective Mapping

 Geometric transform which allows us to remove perspective effect

Threshold Image Warp Perspective Determine Distance

 All road pixels are zero  Analyze area in front of car  Find first non zero pixels  Translate to distance using scaling factor

 How can we know this ‘scaling factor’?  Need to calibrate for particular camera setup  Can be done once for given environment and parameters  Lay 1m object on road surface  Use chessboard pattern of known size  Roughly calculated for project testing

Capture Image Process (OpenCV) Feedback To User

 Provide graphical feedback to user

1. Threshold to remove road surface. Generate transformation matrix 2. Transform image to IPM view 3. Distance determination 4. Graphics overlay 5. Modify algorithm for use on a real time video stream

 Further work possible  Improve thresholding for different road conditions  Improve performance of IPM algorithm  Automatic calibration implementation  Paper submitted to ISSC 2010, awaiting review  S. Tuohy, D. O Cualain, M. Glavin, E. Jones:“Distance Determination for an Automobile Environment using Inverse Perspective Mapping in OpenCV”  Successful implementation of proposed algorithm

Demonstration