The Hough transform is a well-known method for detecting lines. The standard Hough transform (SHT) uses a straight line equation parameterized by an angle and a distance, so the axes of the Hough space are continuous and it is difficult to determine their optimal resolutions for digitization. To resolve this difficulty, we propose a discrete Hough transform (DHT) using line segment representation for line detection. The end points of line segments are used as parameters, so the resolutions of the axes can be easily determined and accumulated bins can be easily smoothed for noise suppression. Therefore, the proposed DHT is more appropriate for detecting isolated lines than the SHT.