Abstract: A chaosgenetic algorithm wasproposed to extractgeometric primitivesdirectly from original images. Comparedwith the traditionalgeometric primitive extraction, this algorithm needs notdo edge detection before geometric primitive extraction. Instead, it directly searches for geometric primitives from an original grey image based on the gradient information. Additionally, this algorithm reduces time and space consumption compared with Hough transform. Simulations show that this method is simple, efficient and reasonably robust.