An algorithm to group edge points into digital line segments with Hough transformation is described in this paper. The edge points are mapped onto the parameter domain discretized at specific intervals, on which peaks appear to represent different line segments. By modeling each peak as a Gaussian function in the parameter domain, a region, to which the edge points are supposed to be mapped, is determined. Then the edge points are grouped and the parameters for a line segment are computed. For the edges including multiple line segments, a sequential Hough transformation, detecting peaks one by one in the parameter domain, is implemented and the points from the region around each peak are grouped, thus the line segments are described. Experiments show the robustness of the algorithm implemented on both generated edges disturbed by different noise levels and real images taken from indoor environment.