Geometry Preserving Active Polygon-Incorporated Sign Detection Algorithm

AbstractA generalized traffic sign detection algorithm incorporating a hybrid active contour (HAC) model has been previously developed to automatically detect all types of traffic signs. Although the HAC model has shown some promising results, there are still some false negatives remaining due to the over-evolution of the HAC model. Therefore, further improvement is needed to reduce the number of these false negatives. This paper is aimed at developing a new geometry-preserving active polygon (GPAP) model to address the over-evolution issue in the HAC model for improving the computation speed. The contributions of this paper include (1) proposing a new geometry-preserving evolution that ensures that the “contour” only evolves at its vertices instead of at every point along the edges; (2) tailoring a new energy function that enables a polygon to effectively converge to traffic sign regions without losing its geometry integrity by using both local color contrast feature and global elongation and rectangular...