GOLD: a Parallel Real-Time Stereo Vision System for Generic Obstacle and Lane Detection


This Project has been supported by Italian CNR through the `Progetto Finalizzato Trasporti 2'.
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The GOLD (Generic Obstacle and Lane Detection) system is a stereo vision-based hardware and software system to be used on moving vehicles to increment road safety.

It is based on the full-custom massively parallel architecture PAPRICA, and it allows to detect both generic obstacles (without constraints on symmetry or shape) and the lane position in a structured environment (with painted lane markings). The output of the processing is displayed on both an on-board monitor and a control-panel to give visual feedbacks to the driver.

The system has been tested both in laboratory and on board of the MOB-LAB experimental land vehicle and demonstrated its robustness with respect to shadows and changing illumination conditions, different road textures, and vehicle movement.

How does the system work?
The localization of obstacles in front of the vehicle is performed by the processing of pairs of stereo images, while lane detection is based on a pattern-matching technique which relies on the presence of road markings.

Both functionalities share the same underlying approach, the Inverse Perspective Mapping. Such a technique is based on a transform that, given a model of the road in front of the vehicle (e.g. flat road), remaps both stereo images into a common domain; any disparity in the remapped images is due to a deviation from the road model, thus making possible to detect potential obstacles.


left image

right image

left remapped image

right remapped image

difference image

the result of obstacle detection

Moreover in the remapped domain the detection of lane markings is extremely simplified since they can be devised as almost vertical lines with constant width. In fact the remapped image represents a bird's eye view of the road surface, allowing lane markings detection through an extremely simple and fast morphological processing.


the acquired image

the remapped image

the result of the
morphological processing
the extraction of the road
geometry
the result of lane detection

Furthermore, since both functionalities are based on the processing of images remapped into the same domain, the fusion of the result of the two processings is straightforward. When one or more obstacles are detected, their position and size are given as input to the lane detection algorithm. The obstacle area is not considered during the lane detection process thus avoiding the risk that the obstacle shape could be confused by a part of a lane marking.


References:


Alessandra Fascioli
Last update: Mar 15 1997