Efficient Stop Sign Detection Using 3D Scene Geometry

Jeffrey SchlosserCS 223bMarch 17, 2008

Problem Statement and Data

Quickly and reliably detect stop signs using data acquired from a camera mounted on an autonomous vehicle

Approach

Haar classifiers used to form representation of stop signs

Utilize known geometry:

x

y

z

pinhole camera

camera coordinate frame

dy

dx

h

Approach (cont.)

000 Xx gKZ x’

y’ Possible locations and scales of stop signs

Results: Single Image

Processing time:

1117 milliseconds

Processing time:

275 milliseconds

Traditional Algorithm (comprehensive search)

Intelligent Algorithm (using 3D scene context)

Results: Image Sequence

Average Processing time: 253 milliseconds

3.9 fps 1.53 FP/image

Average Processing time: 71 milliseconds

14 fps 0.73 FP/image

Intelligent Algorithm (using 3D scene context)

Traditional Algorithm (comprehensive search)

Even faster times possible with better information

Questions?