Extracting lines using a modified Hough transformation

Summary form only given, as follows. An efficient algorithm that extracts lines using a point and a direction parameters from an edge image is discussed. In this algorithm, a line equation is derived for every pair of two edge elements in the image, and lines are extracted using a one-dimensional accumulator (instead of a two-dimensional accumulator, as in the conventional Hough transform methods). The advantages of this algorithm over the conventional Hough transform methods are a fast processing time and less chance of multiple detection for a single line. These advantages come mainly from the facts that the edge elements included in a line are removed from the image when the line is extracted, and the direction parameter of a line is computed only once for a pair of two edge elements which form the line. This means that the processing time does not increase proportionally to the accuracy of lines to be extracted. The algorithm has been implemented on an IBM-PC/AT using the Pascal programming language, and synthetic and real images have been used to show the performance of the algorithm.