Video-rate pipeline straight line extraction algorithm

An efficient algorithm suitable for VLSI implementation for extracting the line segments from the input binary edge image is presented. First it is assumed that an edge detection algorithm is applied to the input image producing an edge map and also recording for each pixel an orientation. To allow a video-rate implementation we scan this map in a raster fashion. Then each line segment is traced in parallel, with a prioritisation scheme dealing with segment intersection and applying colinearity restrictions to avoid merging two segments of different slopes. Since the raster scan oversegments lines to form an orientation from right to left and top to bottom, a merging process is applied simultaneously. Therefore, this algorithm is run in one pass. Finally, a quantitative performance analysis is carried out in which two types of errors are defined. It is shown that this algorithm is robust concerning scaling and rotation. Also, the result of applying this algorithm to natural images is shown.