The color and the shape: Automatic on-line color calibration for autonomous robots

Abstract

This paper presents a method for automatic on-line color calibration of soccer-playing robots. Our method requires a geometrical model of the field-lines in world coordinates, and one of the ball in image coordinates. No specific assumptions are made about the color of the field, ball, or goals except that they are of roughly homogeneous distinct colors, and that the field-lines are bright relative to the field. The classification works by localizing the robot (without using color information), then growing homogeneously colored regions and matching their size and shape with those of the expected regions. If a region matches the expected one, its color is added to the respective color class. This method can be run in a background thread thus enabling the robot to quickly recalibrate in response to changes in illumination. © Springer-Verlag Berlin Heidelberg 2006.