Ground truth evaluation of the Stixel representation using laser scanners

Modern real-time dense stereo vision provides precise depth information for nearly every pixel of an image, indicating stereo cameras as a key sensor for future vehicle safety systems. Efficient analysis of this large amount of data by different tasks running in parallel asks for a medium level representation that decouples application specific analysis from low-level vision. Recently, the so called “Stixel World” has been proposed. It models the objects in the scene, implicitly separates them from the ground plane, encodes the freespace to maneuver and thus represents the scene in a highly compact manner that supports different recognition tasks efficiently. The potential of this new representation depends on the accuracy that can be achieved. Therefore, this paper analyzes the precision of this representation using a high performance laser scanner as reference sensor. The statistical analysis confirms the high accuracy as expected from visual inspection.