Finding straight lines in drawings

Abstract

We have developed an efficient method to extract straight lines at any orientation from a line drawing. The method works by extracting the horizontal and vertical lines using the FAST method, detecting the angles of the other lines and applying the FAST method again while the image is rotated to each corresponding angle. The method is efficient because it is based on very efficient line finding, transposition, and rotation operations which work over the run-length representation of the line drawing.