Final Presentation

```Shane Tuohy

In 2008, rear end collisions accounted for
almost 25% of all injuries sustained in road
Factbook 2008]

Effective distance determination can go a
long way to reducing injuries

Mercedes Pre-Safe
Audi Pre-Sense Plus
Toyota Pre-Collision System



 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


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.
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
```